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1.	Johansson, Patrik, et al. (author) A Patient-Derived Cell Atlas Informs Precision Targeting of Glioblastoma 2020 In: Cell Reports. - : Elsevier BV. - 2211-1247. ; 32:2 Journal article (peer-reviewed)abstract Glioblastoma (GBM) is a malignant brain tumor with few therapeutic options. The disease presents with a complex spectrum of genomic aberrations, but the pharmacological consequences of these aberrations are partly unknown. Here, we report an integrated pharmacogenomic analysis of 100 patient-derived GBM cell cultures from the human glioma cell culture (HGCC) cohort. Exploring 1,544 drugs, we find that GBM has two main pharmacological subgroups, marked by differential response to proteasome inhibitors and mutually exclusive aberrations in TP53 and CDKN2A/B. We confirm this trend in cell and in xenotransplantation models, and identify both Bcl-2 family inhibitors and p53 activators as potentiators of proteasome inhibitors in GBM cells, We can further predict the responses of individual cell cultures to several existing drug classes, presenting opportunities for drug repurposing and design of stratified trials. Our functionally profiled biobank provides a valuable resource for the discovery of new treatments for GBM.
2.	Lundsten, Sara, et al. (author) p53-Mediated Radiosensitization of 177Lu-DOTATATE in Neuroblastoma Tumor Spheroids 2021 In: Biomolecules. - : MDPI. - 2218-273X. ; 11:11 Journal article (peer-reviewed)abstract p53 is involved in DNA damage response and is an exciting target for radiosensitization in cancer. Targeted radionuclide therapy against somatostatin receptors with 177Lu-DOTATATE is currently being explored as a treatment for neuroblastoma. The aim of this study was to investigate the novel p53-stabilizing peptide VIP116 in neuroblastoma, both as monotherapy and together with 177Lu-DOTATATE. Five neuroblastoma cell lines, including two patient-derived xenograft (PDX) lines, were characterized in monolayer cultures. Four out of five were positive for 177Lu-DOTATATE uptake. IC50 values after VIP116 treatments correlated with p53 status, ranging between 2.8–238.2 μM. IMR-32 and PDX lines LU-NB-1 and LU-NB-2 were then cultured as multicellular tumor spheroids and treated with 177Lu-DOTATATE and/or VIP116. Spheroid growth was inhibited in all spheroid models for all treatment modalities. The most pronounced effects were observed for combination treatments, mediating synergistic effects in the IMR-32 model. VIP116 and combination treatment increased p53 levels with subsequent induction of p21, Bax and cleaved caspase 3. Combination treatment resulted in a 14-fold and 1.6-fold induction of MDM2 in LU-NB-2 and IMR-32 spheroids, respectively. This, together with differential MYCN signaling, may explain the varying degree of synergy. In conclusion, VIP116 inhibited neuroblastoma cell growth, potentiated 177Lu-DOTATATE treatment and could, therefore, be a feasible treatment option for neuroblastoma.
3.	Al-Ramadan, Afkar, et al. (author) Analysis of radiation effects in two irradiated tumor spheroid models 2018 In: Oncology Letters. - : Spandidos Publications. - 1792-1074 .- 1792-1082. ; 15:3, s. 3008-3016 Journal article (peer-reviewed)abstract Multicellular spheroids have proven suitable as three-dimensional in vivo-like models of non-vascularized micrometastases. Unlike monolayer-based models, spheroids mirror the cellular milieu and the pathophysiological gradients inside tumor nodules. However, there is limited knowledge of the radiation effects at the molecular level in spheroids of human origin. The present study is a presentation of selected cell biological processes that may easily be analyzed with methods available at routine pathology laboratories. Using gamma irradiated pancreatic neuroendocrine BON1 and colonic adenocarcinoma HCT116 spheroids as model systems, the present study assessed the radiobiological response in these models. Spheroid growth after irradiation was followed over time and molecular responses were subsequently assessed with immunohistochemistry (IHC) staining for descriptive analyses and semi-automatic grading of apoptosis, G(2)-phase and senescence in thin sections of the spheroids. Growth studies demonstrated the BON1 spheroids were slower growing and less sensitive to radiation compared with the HCT116 spheroids. IHC staining for G2-phase was primarily observed in the outer viable P-cell layers of the spheroids, with the 6 Gy irradiated HCT116 spheroids demonstrating a very clear increase in staining intensity compared with unirradiated spheroids. Apoptosis staining results indicated increased apoptosis with increasing radiation doses. No clear association between senescence and radiation exposure in the spheroids were observed. The present results demonstrate the feasibility of the use of multicellular spheroids of human origin in combination with IHC analyses to unravel radiobiological responses at a molecular level. The present findings inspire further investigations, including other relevant IHC-detectable molecular processes in time-and radiation dose-dependent settings.
4.	Andrade, Fernanda, et al. (author) Polymeric micelles targeted against CD44v6 receptor increase niclosamide efficacy against colorectal cancer stem cells and reduce circulating tumor cells in vivo 2021 In: Journal of Controlled Release. - : Elsevier. - 0168-3659 .- 1873-4995. ; 331, s. 198-212 Journal article (peer-reviewed)abstract Colorectal cancer (CRC) is a highly prevalent disease worldwide. Patient survival is hampered by tumor relapse and the appearance of drug-resistant metastases, which are sustained by the presence of cancer stem cells (CSC). Specific delivery of anti-CSC chemotherapeutic drugs to tumors by using targeted drug delivery systems that can also target CSC sub-population might substantially improve current clinical outcomes. CD44v6 is a robust biomarker for advanced CRC and CSC, due to its functional role in tumorigenesis and cancer initiation process. Here, we show that CD44v6-targeted polymeric micelles (PM) loaded with niclosamide (NC S), a drug against CSC, is a good therapeutic strategy against colorectal CSC and circulating tumor cells (CTC) in vivo. HCT116 cells were sorted according to their CD44v6 receptor expression into CD44v6+ (high) and CDv44v6- (low) subpopulations. Accordingly, CD44v6+ cells presented stemness properties, such as overexpression of defined stemness markers (ALDH1A1, CD44v3 and CXCR4) and high capacity to form colonspheres in low attachment conditions. NC S-loaded PM functionalized with an antibody fragment against CD44v6 (Fab-CD44v6) presented adequate size, charge, and encapsulation efficiency. In addition, Fab-CD44v6 significantly increased PM internalization in CD44v6+ cells. Further, encapsulation of NCS improved its effectiveness in vitro, particularly against colonspheres, and allowed to increase its intravenous dosage in vivo by increasing the amount of NCS able to be administered without causing toxicity. Remarkably, functionalized PM accumulate in tumors and significantly reduce CTC in vivo. In conclusion, CD44v6 targeted PM meet the essential conditions to become an efficient anti-CSC therapy.
5.	Berglund, Hanna, et al. (author) p53 stabilisation potentiates [177Lu]Lu-DOTATATE treatment in neuroblastoma xenografts 2023 In: European Journal of Nuclear Medicine and Molecular Imaging. - : Springer. - 1619-7070 .- 1619-7089. Journal article (peer-reviewed)abstract PurposeMolecular radiotherapy is a treatment modality that is highly suitable for targeting micrometastases and [177Lu]Lu-DOTATATE is currently being explored as a potential novel treatment option for high-risk neuroblastoma. p53 is a key player in the proapoptotic signalling in response to radiation-induced DNA damage and is therefore a potential target for radiosensitisation.MethodsThis study investigated the use of the p53 stabilising peptide VIP116 and [177Lu]Lu-DOTATATE, either alone or in combination, for treatment of neuroblastoma tumour xenografts in mice. Initially, the uptake of [177Lu]Lu-DOTATATE in the tumours was confirmed, and the efficacy of VIP116 as a monotherapy was evaluated. Subsequently, mice with neuroblastoma tumour xenografts were treated with placebo, VIP116, [177Lu]Lu-DOTATATE or a combination of both agents.ResultsThe results demonstrated that monotherapy with either VIP116 or [177Lu]Lu-DOTATATE significantly prolonged median survival compared to the placebo group (90 and 96.5 days vs. 50.5 days, respectively). Notably, the combination treatment further improved median survival to over 120 days. Furthermore, the combination group exhibited the highest percentage of complete remission, corresponding to a twofold increase compared to the placebo group. Importantly, none of the treatments induced significant nephrotoxicity. Additionally, the therapies affected various molecular targets involved in critical processes such as apoptosis, hypoxia and angiogenesis.ConclusionIn conclusion, the combination of VIP116 and [177Lu]Lu-DOTATATE presents a promising novel treatment approach for neuroblastoma. These findings hold potential to advance research efforts towards a potential cure for this vulnerable patient population.
6.	Bondza, Sina, et al. (author) Bivalent binding on cells varies between anti-CD20 antibodies and is dose-dependent 2020 In: mAbs. - : TAYLOR & FRANCIS INC. - 1942-0862 .- 1942-0870. ; 12:1 Journal article (peer-reviewed)abstract Based on their mechanism of action, two types of anti-CD20 antibodies are distinguished: Type I, which efficiently mediate complement-dependent cytotoxicity, and Type II, which instead are more efficient in inducing direct cell death. Several molecular characteristics of these antibodies have been suggested to underlie these different biological functions, one of these being the manner of binding to CD20 expressed on malignant B cells. However, the exact binding model on cells is unclear. In this study, the binding mechanism of the Type I therapeutic antibodies rituximab (RTX) and ofatumumab (OFA) and the Type II antibody obinutuzumab (OBI) were established by real-time interaction analysis on live cells. It was found that the degree of bivalent stabilization differed for the antibodies: OFA was stabilized the most, followed by RTX and then OBI, which had the least amount of bivalent stabilization. Bivalency inversely correlated with binding dynamics for the antibodies, with OBI displaying the most dynamic binding pattern, followed by RTX and OFA. For RTX and OBI, bivalency and binding dynamics were concentration dependent; at higher concentrations the interactions were more dynamic, whereas the percentage of antibodies that bound bivalent was less, resulting in concentration-dependent apparent affinities. This was barely noticeable for OFA, as almost all molecules bound bivalently at the tested concentrations. We conclude that the degree of bivalent binding positively correlates with the complement recruiting capacity of the investigated CD20 antibodies.
7.	Bondza, Sina, 1990-, et al. (author) Bivalent Binding on Cells varies between CD20 Antibodies and is Dose-dependent Other publication (other academic/artistic)
8.	Bondza, Sina (author) Deciphering Binding Patterns of Therapeutic Antibodies with Immune Cells : From Method Development to Application 2020 Doctoral thesis (other academic/artistic)abstract Reversible binding, for example between signaling molecules and receptors on the cell surface, is one of the main means to communicate information in cellular systems. Knowledge about how molecules interact is crucial for both understanding biological function and for therapeutic intervention. The cellular environment often makes ligand-receptor interactions complex with the membrane providing structural support and containing other components that interfere with the interaction. One of the fastest growing drug classes for targeting cellular receptors are monoclonal antibodies (mAb), in particular within oncology. Therapeutic mAbs can have direct effects on target cells mediated via the Fab-domain and immune-related effects that are mediated via the Fc-domain. An example of the latter is activation of the complement system by binding of its first component C1q to Fc-domains. Furthermore, immune cells can recognize Fc-domains via Fc-receptors and cause target cell death by a process called antibody-dependent cellular cytotoxicity (ADCC).Increased understanding about structure-binding-function relationships facilitates rational drug design, as has been demonstrated with the development of next-generation mAbs that harbor a structural modification on their Fc-domain that strengthens the interaction with immune cells thereby increasing ADCC efficacy. In this thesis, assays for characterizing mAb binding and mAb mediated interactions on live cells were developed and applied to illustrate how detailed knowledge about binding processes helps to understand the relation between binding and biological function.Paper I describes a protocol for real-time interaction analysis of antibodies with live immune cells enabling binding measurements in a relevant cellular context with the data resolution needed to study complex binding processes.Paper II presents a novel real-time proximity assay that allows to study binding kinetics in connection with receptor dimerization and clustering thereby aiding in decipher complex interactions.In paper III, binding patterns of the CD20 mAbs rituximab, ofatumumab and obinituzumab were established on cells revealing that the fraction of bivalently bound mAbs differed resulting in dose-dependent affinities for rituximab and obinituzumab.In paper IV, a C1q binding assay to mAb opsonized cells was developed and it was shown that a higher degree of bivalent binding correlated with stronger C1q binding for the CD20 mAbs evaluated in paper III.In paper V, an assay to study mAb mediated cell-cell interactions was set-up and it was found that neutrophil engagement with target cells was similar for antibodies of IgG and IgA isotype.
9.	Bondza, Sina, et al. (author) Novel Real-Time Proximity Assay for Characterizing Multiple Receptor Interactions on Living Cells 2017 In: Analytical Chemistry. - : American Chemical Society (ACS). - 0003-2700 .- 1520-6882. ; 89:24, s. 13212-13218 Journal article (peer-reviewed)abstract Cellular receptor activity is often controlled through complex mechanisms involving interactions with multiple molecules, which can be soluble ligands and/or other cell surface molecules. In this study, we combine a fluorescence-based technology for real-time interaction analysis with fluorescence quenching to create a novel time-resolved proximity assay to study protein-receptor interactions on living cells. This assay extracts the binding kinetics and affinity for two proteins if they bind in proximity on the cell surface. One application of real-time proximity interaction analysis is to study relative levels of receptor dimerization. The method was primarily evaluated using the HER2 binding antibodies Trastuzumab and Pertuzumab and two EGFR binding antibodies including Cetuximab. Using Cetuximab and Trastuzumab, proximity of EGFR and HER2 was investigated before and after treatment of cells with the tyrosine-kinase inhibitor Gefitinib. Treated cells displayed 50% increased proximity signal, whereas the binding characteristics of the two antibodies were not significantly affected, implying an increase in the EGFR-HER2 dimer level. These results demonstrate that real-time proximity interaction analysis enables determination of the interaction rate constants and affinity of two ligands while simultaneously quantifying their relative colocalization on living cells.
10.	Chandramohan, Arun, et al. (author) Design-rules for stapled peptides with in vivo activity and their application to Mdm2/X antagonists 2024 In: Nature Communications. - : Springer Nature. - 2041-1723. ; 15:1 Journal article (peer-reviewed)abstract Although stapled α-helical peptides can address challenging targets, their advancement is impeded by poor understandings for making them cell permeable while avoiding off-target toxicities. By synthesizing >350 molecules, we present workflows for identifying stapled peptides against Mdm2(X) with in vivo activity and no off-target effects. Key insights include a clear correlation between lipophilicity and permeability, removal of positive charge to avoid off-target toxicities, judicious anionic residue placement to enhance solubility/behavior, optimization of C-terminal length/helicity to enhance potency, and optimization of staple type/number to avoid polypharmacology. Workflow application gives peptides with >292x improved cell proliferation potencies and no off-target cell proliferation effects ( > 3800x on-target index). Application of these ‘design rules’ to a distinct Mdm2(X) peptide series improves ( > 150x) cellular potencies and removes off-target toxicities. The outlined workflow should facilitate therapeutic impacts, especially for those targets such as Mdm2(X) that have hydrophobic interfaces and are targetable with a helical motif.
11.	Elfving, Hedvig (author) Improving the diagnostic armamentarium of lung cancer 2024 Doctoral thesis (other academic/artistic)abstract Lung cancer is the leading cause of cancer-related death globally, with non-small cell lung cancer (NSCLC) constituting 85% of cases. The introduction of immunotherapies and targeted therapies have dramatically improved the prognosis and outcome for a subset of patients, and stressed the development of diagnostic tools for effective patient selection. This thesis addresses different aspects of current and future diagnostic strategies in NSCLC patients.In Paper I, an immunohistochemical assay targeting the neurotropic tropomyosin receptor kinase (NTRK) was evaluated on tissue microarrays (TMAs) from a well-characterized NSCLC cohort. Although a few cases showed positive staining, none were positive in the reference molecular testing, highlighting the rarity of this targetable aberration and underscoring the value of cost-effective screening methods.In Paper II, paired patient samples (biopsy, TMA, and surgical specimen) were evaluated regarding the immunohistochemical staining for PD-L1. The results indicated a strong correlation between the PD-L1 expression on biopsy and TMA compared with the tumor whole slide, suggesting that tumor heterogeneity has minor relevance for PD-L1 evaluation.In Paper III, paired tissue samples (biopsy, TMA, and surgical specimen) were evaluated regarding infiltrating CD3+ immune cells. Only weak correlation was found between the biopsies and tumor whole slide, while the agreement between the whole slide and TMA was higher. These results question the use of biopsies for immune cell quantification, while supporting the TMA as a reliable tool in cancer research.In Paper IV, the amount and distribution of tertiary lymphoid structures (TLS) was annotated on scanned tumor whole slides. TLS were present in most of the tumors and correlated with the abundance of specific immune cell subsets. Higher number of TLS were associated with longer survival, particularly in adenocarcinomas. High tumor mutational burden was associated with higher numbers of periphery TLS. These results provide a rationale for using TLS metrics as a diagnostic marker for NSCLC patients undergoing surgical resection.In summary, this thesis addresses challenges in prognostic and predictive lung cancer diagnostics in the areas of targeted therapy and immunotherapy. The results provide crucial insights into tumor heterogeneity that may impact clinical decision-making and aid scientists in selecting appropriate tissue sources for translational and clinical cancer research.
12.	Elmsjö, Albert, et al. (author) Method selectivity evaluation using the co-feature ratio in LC/MS metabolomics : Comparison of HILIC stationary phase performance for the analysis of plasma, urine and cell extracts. 2018 In: Journal of Chromatography A. - : Elsevier BV. - 0021-9673 .- 1873-3778. ; 1568, s. 49-56 Journal article (peer-reviewed)abstract Evaluation of the chromatographic separation in metabolomics studies has primarily been done using preselected sets of standards or by counting the number of detected features. An alternative approach is to calculate each feature's co-feature ratio, which is a combined selectivity measurement for the separation (i.e. extent of co-elution) and the MS-signal (i.e. adduct formation and in-source fragmentation). The aim of this study was to demonstrate how the selectivity of different HILIC stationary phases can be evaluated using the co-feature ratio approach. The study was based on three sample types; plasma, urine and cell extracts. Samples were analyzed on an UHPLC-ESI-Q-ToF system using an amide, a bare silica and a sulfobetaine stationary phase. For each feature, a co-feature ratio was calculated and used for multivariate analysis of the selectivity differences between the three stationary phases. Unsupervised PCA models indicated that the co-feature ratios were highly dependent on type of stationary phase. For several metabolites a 15-30 fold difference in the co-feature ratio were observed between the stationary phases. Observed selectivity differences related primarily to the retention patterns of unwanted matrix components such as inorganic salts (detected as salt clusters), glycerophospholipids, and polyethylene glycols. These matrix components affected the signal intensity of co-eluting metabolites by interfering with the ionization efficiency and/or their adduct formation. Furthermore, the retention pattern of these matrix components had huge influence on the number of detected features. The co-feature ratio approach has successfully been applied for evaluation of the selectivity performance of three HILIC stationary phases. The co-feature ratio could therefore be used in metabolomics for developing selective methods fit for their purpose, thereby avoiding generic analytical approaches, which are often biased, as type and amount of interfering matrix components are metabolome dependent.
13.	Erngren, Ida, et al. (author) Adduct formation in electrospray ionisation-mass spectrometry with hydrophilic interaction liquid chromatography is strongly affected by the inorganic ion concentration of the samples 2019 In: Journal of Chromatography A. - : ELSEVIER SCIENCE BV. - 0021-9673 .- 1873-3778. ; 1600, s. 174-182 Journal article (peer-reviewed)abstract Hydrophilic interaction liquid chromatography (HILIC)/electrospray ionisation-mass spectrometry (ESI-MS) has gained interest for the analysis of polar analytes in bioanalytical applications in recent years. However, ESI-MS is prone to adduct formation of analytes. In contrast to reversed phase chromatography, small inorganic ions have retention in HILIC, i.e. analytes and inorganic ions may co-elute, which could influence the adduct formation. In the present paper, it was demonstrated that the co-elution of sodium ions or potassium ions and analytes in HILIC/ESI-MS affect the adduct formation and that different concentrations of sodium ions and potassium ions in biological samples could have an impact on the quantitative response of the respective adducts as well as the quantitative response of the protonated adduct. The co-elution also lead to cluster formation of analytes and sodium formate or potassium formate, causing extremely complicated spectra. In analytical applications using HILIC/ESI-MS where internal standards are rarely used or not properly matched, great care needs to be taken to ensure minimal variation of inorganic ion concentration between samples. Moreover, the use of alkali metal ion adducts as quantitative target ions in relative quantitative applications should be made with caution if proper internal standards are not used.
14.	Erngren, Ida, 1989-, et al. (author) Improved sensitivity in hydrophilic interaction liquid chromatography-electrospray-mass spectrometry after removal of sodium and potassium ions from biological samples 2021 In: Metabolites. - : MDPI. - 2218-1989 .- 2218-1989. ; 11:3 Journal article (peer-reviewed)abstract Inorganic ions, such as sodium and potassium, are present in all biological matrices and are sometimes also added during sample preparation. However, these inorganic ions are known to hamper electrospray ionization -mass spectrometry (ESI-MS) applications, especially in hydrophilic interaction liquid chromatography (HILIC) where they are retained and can be detected as adducts and clusters with mobile phase components or analytes. The retention of inorganic ions leads to co-elution with analytes and as a result ion-suppression, extensive adduct formation and problems with reproducibility. In the presented work, a sample preparation method using cation exchange solid phase extraction (SPE) was developed to trap Na+ and K+ ions from human blood plasma and head and neck cancer cells for the analysis of small cationic, anionic as well as neutral organic analytes. The investigated analytes were small, hydrophilic compounds typically in focus in metabolomics studies. The samples were analyzed using full-scan HILIC-ESI-quadrupole time of flight (QTOF)-MS with an untargeted, screening approach. Method performance was evaluated using multivariate data analysis as well as relative quantifications, spiking of standards to evaluate linearity of response and post-column infusion to study ion-suppression. In blood plasma, the reduction of sodium and potassium ion concentration resulted in improved sensitivity increased signal intensity for 19 out of 28 investigated analytes, improved linearity of response, reduced ion-suppression and reduced cluster formation as well as adduct formation. Thus, the presented method has significant potential to improve data quality in metabolomics studies.
15.	Fernandes, Sara R.G., et al. (author) Photoactive immunoconjugates for targeted photodynamic therapy of cancer 2023 In: Journal of Photochemistry and Photobiology. B. - : Elsevier. - 1011-1344 .- 1873-2682. ; 243 Journal article (peer-reviewed)abstract Photodynamic therapy (PDT) has been used as an alternative or as a complement of conventional approaches for cancer treatment. In PDT, the reactive oxygen species (ROS) produced from the interaction between the photosensitizer (PS), visible light and molecular oxygen, kill malignant cells by triggering a cascade of cytotoxic reactions. In this process, the PS plays an extremely important role in the effectiveness of the therapy. In the present work, a new photoimmunoconjugate (PIC), based on cetuximab and the known third generation PS-glycophthalocyanine ZnPcGal4, was synthesized via reductive amination. The rationale behind this was the simultaneous cancer-associated specific targeting of PIC and photosensitization of targeted receptor positive cells. Varied reaction parameters and photodynamic conditions, such as PS concentrations and both type and intensities of light, were optimized. ZnPcGal4 showed significant photoactivity against EGFR expressing A431, EGFR-transfected HCT116 and HT29 cells when irradiated with white light of stronger intensity (38 mW/cm2). Similarly, the synthesized PICs-T1 and T2 also demonstrated photoactivity with high intensity white light. The best optimized PIC: sample 28 showed no precipitation and aggregation when inspected visually and analyzed through SE-HPLC. Fluorescence excitation of sample 28 and 125I-sample 28 radioconjugate (125I-PIC, 125I-radiolabeling yield ≥95%, determined with ITLC) at 660 nm showed presence of appended ZnPcGal4. In addition, simultaneous fluorescence and radioactivity detection of the 125I-PIC in serum and PBS (pH 7.4) for the longest incubated time point of 72 h, respectively, and superimposed signals thereof demonstrated ≥99% of loading and/or labeling yield, assuring overall stability of the PIC and corresponding PIC-radioconjugate w.r.t. both the appended ZnPcGal4 and bound-125I. Moreover, real-time binding analyses on EGFR-transfected HCT116 cells showed specific binding of 125I-PIC, suggesting no alternation in the binding kinetics of the mAb after appending it with ZnPcGal4. These results suggest dual potential applications of synthesized PICs both for PDT and radio-immunotherapy of cancer.
16.	Haylock, Anna-Karin, et al. (author) Generation and evaluation of antibody agents for molecular imaging of CD44v6-expressing cancers 2017 In: Oncotarget. - : Impact Journals, LLC. - 1949-2553. ; 8:39, s. 65152-65170 Journal article (peer-reviewed)abstract Aim: The aim of this study was to generate and characterize scFv antibodies directed to human CD44v6, as well as to radiolabel and evaluate top candidates in vitro and in vivo for their potential use in CD44v6-targeted molecular imaging in cancer patients.Materials and methods: Phage display selections were used to isolate CD44v6-specific scFvs. A chain shuffling strategy was employed for affinity maturation based on a set of CD44v6-specific first-generation clones. Two second-generation scFv clones were then chosen for labeling with 111In or 125I and assessed for CD44v6-specific binding on cultured tumor cells. In vivo uptake and distribution was evaluated in tumor-bearing mice using a dual tumor model. Finally, a proof-of-concept small animal PET-CT study was performed on one of the candidates labeled with 124I.Results: Two affinity-matured clones, CD44v6-scFv-A11 and CD44v6-scFv-H12, displayed promising binding kinetics. Seven out of eight radiolabeled conjugates demonstrated CD44v6-specific binding. In vivo studies on selected candidates demonstrated very advantageous tumor-to-organ ratios, in particular for iodinated conjugates, where 125I-labeled scFvs exhibited favorable kinetics and tumor-to-blood ratios above five already at 24 hours p. i.. The small animal PET-CT study using 124I-labeled CD44v6-scFv-H12 was in line with the biodistribution data, clearly visualizing the high CD44v6-expressing tumor.Conclusion: The single chain fragments, CD44v6-scFv-A11 and CD44v6-scFv-H12 specifically bind to CD44v6, and the radiolabeled counterparts provide high tumor-to-blood ratios and fast clearance from organs and blood. We conclude that radioiodinated CD44v6-scFv-A11 and CD44v6-scFv-H12 possess features highly suitable for stringent molecular imaging.
17.	Haylock, Anna-Karin, et al. (author) In vivo characterization of the novel CD44v6-targeting Fab fragment AbD15179 for molecular imaging of squamous cell carcinoma : a dual-isotope study 2014 In: EJNMMI Research. - 2191-219X. ; 4 Journal article (peer-reviewed)abstract BACKGROUND: Patients with squamous cell carcinoma in the head and neck region (HNSCC) offer a diagnostic challenge due to difficulties to detect small tumours and metastases. Imaging methods available are not sufficient, and radio-immunodiagnostics could increase specificity and sensitivity of diagnostics. The objective of this study was to evaluate, for the first time, the in vivo properties of the radiolabelled CD44v6-targeting fragment AbD15179 and to assess its utility as a targeting agent for radio-immunodiagnostics of CD44v6-expressing tumours.METHODS: The fully human CD44v6-targeting Fab fragment AbD15179 was labelled with 111In or 125I, as models for radionuclides suitable for imaging with SPECT or PET. Species specificity, antigen specificity and internalization properties were first assessed in vitro. In vivo specificity and biodistribution were then evaluated in tumour-bearing mice using a dual-tumour and dual-isotope setup.RESULTS: Both species-specific and antigen-specific binding of the conjugates were demonstrated in vitro, with no detectable internalization. The in vivo studies demonstrated specific tumour binding and favourable tumour targeting properties for both conjugates, albeit with higher tumour uptake, slower tumour dissociation, higher tumour-to-blood ratio and higher CD44v6 sensitivity for the 111In-labelled fragment. In contrast, the 125I-Fab demonstrated more favourable tumour-to-organ ratios for liver, spleen and kidneys.CONCLUSIONS: We conclude that AbD15179 efficiently targets CD44v6-expressing squamous cell carcinoma xenografts, and particularly, the 111In-Fab displayed high and specific tumour uptake. CD44v6 emerges as a suitable target for radio-immunodiagnostics, and a fully human antibody fragment such as AbD15179 can enable further clinical imaging studies.
18.	Ingelshed, Katrine, et al. (author) MDM2/MDMX inhibition by Sulanemadlin synergizes with anti-Programmed Death 1 immunotherapy in wild-type p53 tumors 2024 In: iScience. - : Elsevier. - 2589-0042. ; 27:6 Journal article (peer-reviewed)abstract Immunotherapy has revolutionized cancer treatment but its efficacy depends on a robust immune response in the tumor. Silencing of the tumor suppressor p53 is common in tumors and can affect the recruitment and activation of different immune cells, leading to immune evasion and poor therapy response. We found that the p53 activating stapled peptide MDM2/MDMX inhibitor Sulanemadlin (ALRN-6924) inhibited p53 wild-type cancer cell growth in vitro and in vivo. In mice carrying p53 wild-type CT26.WT tumors, monotherapy with the PD-1 inhibitor DX400 or Sulanemadlin delayed tumor doubling time by 50% and 37%, respectively, while combination therapy decreased tumor doubling time by 93% leading to an increased median survival time. Sulanemadlin treatment led to increased immunogenicity and combination treatment with PD-1 inhibition resulted in an increased tumor infiltration of lymphocytes. This combination treatment strategy could potentially turn partial responders into responders of immunotherapy, expanding the patient target group for PD-1-targeting immunotherapy.
19.	Ingelshed, Katrine, et al. (author) The MDM2 Inhibitor Navtemadlin Arrests Mouse Melanoma Growth In Vivo and Potentiates Radiotherapy 2022 In: Cancer Research Communications. - : American Association For Cancer Research (AACR). - 2767-9764. ; 2:9, s. 1075-1088 Journal article (peer-reviewed)abstract The tumor suppressor protein p53 is mutated in close to 50% of human tumors and is dysregulated in many others, for instance by silencing or loss of p14ARF. Under steady-state conditions, the two E3 ligases MDM2/MDM4 interact with and inhibit the transcriptional activity of p53. Inhibition of p53–MDM2/4 interaction to reactivate p53 in tumors with wild-type (WT) p53 has therefore been considered a therapeutic strategy. Moreover, studies indicate that p53 reactivation may synergize with radiation and increase tumor immunogenicity. In vivo studies of most MDM2 inhibitors have utilized immunodeficient xenograft mouse models, preventing detailed studies of action of these molecules on the immune response. The mouse melanoma cell line B16-F10 carries functional, WT p53 but does not express the MDM2 regulator p19ARF. In this study, we tested a p53-MDM2 protein–protein interaction inhibitor, the small molecule Navtemadlin, which is currently being tested in phase II clinical trials. Using mass spectrometry–based proteomics and imaging flow cytometry, we identified specific protein expression patterns following Navtemadlin treatment of B16-F10 melanoma cells compared with their p53 CRISPR-inactivated control cells. In vitro, Navtemadlin induced a significant, p53-dependent, growth arrest but little apoptosis in B16-F10 cells. When combined with radiotherapy, Navtemadlin showed synergistic effects and increased apoptosis. In vivo, Navtemadlin treatment significantly reduced the growth of B16-F10 melanoma cells implanted in C57Bl/6 mice. Our data highlight the utility of a syngeneic B16-F10 p53+/+ mouse melanoma model for assessing existing and novel p53-MDM2/MDM4 inhibitors and in identifying new combination therapies that can efficiently eliminate tumors in vivo.Significance:The MDM2 inhibitor Navtemadlin arrests mouse tumor growth and potentiates radiotherapy. Our results support a threshold model for apoptosis induction that requires a high, prolonged p53 signaling for cancer cells to become apoptotic.
20.	Kennedy, Patrick J., et al. (author) Fab-conjugated PLGA nanoparticles effectively target cancer cells expressing human CD44v6 2018 In: Acta Biomaterialia. - : Elsevier BV. - 1742-7061 .- 1878-7568. ; 81, s. 208-218 Journal article (peer-reviewed)abstract Targeting of CD44 isoforms containing exon v6 (CD44v6) represents a viable strategy for the therapy and/or early diagnosis of metastatic cancers of the epithelium (e.g. gastric and colorectal cancer). We developed and characterized poly(lactic-co-glycolic acid) (PLGA)-based nanoparticles (NPs) modified with polyethylene glycol (PEG) and engrafted, by site-directed conjugation, with an engineered human Fab that specifically target human CD44v6 (v6 Fab-PLGA NPs). The v6 Fab-PLGA NPs displayed spherical morphology around 300 nm and were negatively charged. They strongly bound to a CD44v6-derived peptide and, more importantly, to cells that endogenously and exogenously express CD44v6, but not to non expressing cells and cells expressing the standard isoform of CD44. The v6 Fab-PLGA NPs also recognized CD44v6 in tumor sections from cells grown subcutaneously within mice. The NPs had nominal cytotoxicity at 50 mu g/mL and withstood simulated intestinal fluid exposure. Interestingly, v6 Fab-PLGA NPs cryopreserved in 10% trehalose and stored maintained specific cell binding. In conclusion, we envision NPs targeting CD44v6 as potential in vivo diagnostic agents and/or as anti-cancer agents in patients previously stratified with CD44v6(+) carcinomas. Statement of Significance The v6 Fab-PLGA NPs displayed many favorable qualities as a potential CD44v6-targeted drug and/or diagnostic delivery agent. The NPs were designed for optimal ligand orientation and for immediate administration into humans. v6 Fab-PLGA NPs strongly bound to cells that endogenously and exogenously express CD44v6, but not to non-expressing cells and cells expressing the standard isoform of CD44. Binding ability was retained after freeze-drying and long-term storage, providing evidences on the stability of Fab-functionalized NPs. These NPs can potentially be used as an in vivo diagnostic from parenteral or oral/rectal administration.
21.	Kennedy, Patrick J., et al. (author) Impact of surfactants on the target recognition of Fab-conjugated PLGA nanoparticles 2018 In: European journal of pharmaceutics and biopharmaceutics. - : Elsevier. - 0939-6411 .- 1873-3441. ; 127, s. 366-370 Journal article (peer-reviewed)abstract Targeted drug delivery with nanoparticles (NPs) requires proper surface ligand presentation and availability. Surfactants are often used as stabilizers in the production of targeted NPs. Here, we evaluated the impact of surfactants on ligand functionalization and downstream molecular recognition. Our model system consisted of fluorescent poly(lactic-co-glycolic acid) (PLGA) NPs that were nanoprecipitated in one of a small panel of commonly-used surfactants followed by equivalent washes and conjugation of an engineered Fab antibody fragment. Size, polydispersity index and zeta potential were determined by dynamic light scattering and laser Doppler anemometry, and Fab presence on the NPs was assessed by enzyme-linked immunosorbent assay. Most importantly, Fab-decorated NP binding to the cell surface receptor was monitored by fluorescence-activated cell sorting. 2% polyvinyl alcohol, 1% sodium cholate, 0.5% Pluronic F127 (F127) and 2% Tween-80 were initially tested. Of the four surfactants tested, PLGA NPs in 0.5% F127 and 2% Tween-80 had the highest cell binding. These two surfactants were then retested in two different concentrations, 0.5% and 2%. The Fab-decorated PLGA NPs in 2% F127 had the highest cell binding. This study highlights the impact of common surfactants and their concentrations on the downstream targeting of ligand-decorated NPs. Similar principles should be applied in the development of future targeted nanosystems where surfactants are employed.
22.	Kundu, S K, et al. (author) Targeted therapy in head and neck cancer 2012 In: Tumor Biology. - : Springer Science and Business Media LLC. - 1010-4283 .- 1423-0380. ; 33:3, s. 707-721 Journal article (peer-reviewed)abstract Head and neck squamous cell carcinoma (HNSCC) of multi-factorial etiopathogenesis is rising worldwide. Treatment-associated toxicity problems and treatment failure in advanced disease stages with conventional therapies have necessitated a focus on alternative strategies. Molecular targeted therapy, with the potential for increased selectivity and fewer adverse effects, hold promise in the treatment of HNSCC. In an attempt to improve outcomes in HNSCC, targeted therapeutic strategies have been developed. These strategies are focusing on the molecular biology of HNSCC in an attempt to target selected pathways involved in carcinogenesis. Inhibiting tumor growth and metastasis by focusing on specific protein or signal transduction pathways or by targeting the tumor microenvironment or vasculature are some of the new approaches. Targeted agents for HNSCC expected to improve the effectiveness of current therapy include EGFR inhibitors (Cetuximab, Panitumumab, Zalutumumab), EGFR tyrosine kinase inhibitors (Gefitinib, Erloitinib), VEGFR inhibitors (Bevacizumab, Vandetanib), and various inhibitors of, e.g., Src-family kinase, PARP, proteasome, mTOR, COX, and heat shock protein. Moreover, targeted molecular therapy can also act as a complement to other existing cancer therapies. Several studies have demonstrated that the combination of targeting techniques with conventional current treatment protocols may improve the treatment outcome and disease control, without exacerbating the treatment related toxicities. Some of the targeted approaches have been proved as promising therapeutic potentials and are already in use, whereas remainder exhibits mixed result and necessitates further studies. Identification of predictive biomarkers of resistance or sensitivity to these therapies remains a fundamental challenge in the optimal selection of patients most likely to benefit from targeted treatment.
23.	Lindell Jonsson, Eva, et al. (author) Exploring Radiation Response in Two Head and Neck Squamous Carcinoma Cell Lines Through Metabolic Profiling 2019 In: Frontiers in Oncology. - : Frontiers Media SA. - 2234-943X. ; 9 Journal article (peer-reviewed)abstract Head and neck squamous cell carcinoma (HNSCC) is the sixth most common form of cancer worldwide. Radiotherapy, with or without surgery, represents the major approach to curative treatment. However, not all tumors are equally sensitive to irradiation. It is therefore of interest to apply newer system biology approaches (e.g., metabolic profiling) in squamous cancer cells with different radiosensitivities in order to provide new insights on the mechanisms of radiation response. In this study, two cultured HNSCC cell lines from the same donor, UM-SCC-74A and UM-SCC-74B, were first genotyped using Short Tandem Repeat (STR), and assessed for radiation response by the means of clonogenic survival and growth inhibition assays. Thereafter, cells were cultured, irradiated and collected for subsequent metabolic profiling analyses using liquid chromatography-mass spectrometry (LC-MS). STR verified the similarity of UM-SCC-74A and UM-SCC-74B cells, and three independent assays proved UM-SCC-74B to be clearly more radioresistant than UM-SCC-74A. The LC-MS metabolic profiling demonstrated significant differences in the intracellular metabolome of the two cell lines before irradiation, as well as significant alterations after irradiation. The most important differences between the two cell lines before irradiation were connected to nicotinic acid and nicotinamide metabolism and purine metabolism. In the more radiosensitive UM-SCC-74A cells, the most significant alterations after irradiation were linked to tryptophan metabolism. In the more radioresistant UM-SCC-74B cells, the major alterations after irradiation were connected to nicotinic acid and nicotinamide metabolism, purine metabolism, the methionine cycle as well as the serine, and glycine metabolism. The data suggest that the more radioresistant cell line UM-SCC-74B altered the metabolism to control redox-status, manage DNA-repair, and change DNA methylation after irradiation. This provides new insights on the mechanisms of radiation response, which may aid future identification of biomarkers associated with radioresistance of cancer cells.
24.	Lundgren Mortensen, Anja, et al. (author) The Stapled Peptide PM2 Stabilizes p53 Levels and Radiosensitizes Wild-Type p53 Cancer Cells 2019 In: Frontiers in Oncology. - : Frontiers Media SA. - 2234-943X. ; 9 Journal article (peer-reviewed)abstract The tumor suppressor p53 is a key mediator of cellular stress and DNA damage response cascades and is activated after exposure to ionizing radiation. Amplifying wild-type p53 expression by targeting negative regulators such as MDM2 in combination with external beam radiotherapy (EBRT) may result in increased therapeutic effects. The novel stapled peptide PM2 prevents MDM2 from suppressing wild-type p53, and is thus a promising agent for therapeutic combination with EBRT. Effects of PM2 and potential PM2-induced radiosensitivity were assessed in a panel of cancer cell lines using 2D cell viability assays. Western Blot and flow cytometric analyses were used to investigate the mechanisms behind the observed effects in samples treated with PM2 and EBRT. Finally, PM2-treatment combined with EBRT was evaluated in an in vitro 3D spheroid model. PM2-therapy decreased cell viability in wild-type p53, HPV-negative cell lines. Western Blotting and flow cytometry confirmed upregulation of p53, as well as initiation of p53-mediated apoptosis measured by increased cleaved caspase-3 and Noxa activity. Furthermore, 3D in vitro tumor spheroid experiments confirmed the superior effects of the combination, as the only treatment regime resulting in growth inhibition and complete spheroid disintegration. We conclude that PM2 induces antitumorigenic effects in wt p53 HPV-negative cancer cells and potentiates the effects of EBRT, ultimately resulting in tumor eradication in a 3D spheroid model. This strategy shows great potential as a new wt p53 specific tumor-targeting compound, and the combination of PM2 and EBRT could be a promising strategy to increase therapeutic effects and decrease adverse effects from radiotherapy.
25.	Lundsten, Sara, et al. (author) Potentiating Lu-177-DOTATATE Therapy By HSP90 Inhibition - First In Vivo Study 2018 In: European Journal of Nuclear Medicine and Molecular Imaging. - : Springer. - 1619-7070 .- 1619-7089. ; 45, s. S12-S13 Journal article (other academic/artistic)
26.	Lundsten, Sara, et al. (author) Radioiodination Of Small Stapled Peptides For p53 Therapy 2017 In: EUROPEAN JOURNAL OF NUCLEAR MEDICINE AND MOLECULAR IMAGING. - : SPRINGER. - 1619-7070 .- 1619-7089. ; 44, s. S769-S769 Conference paper (peer-reviewed)
27.	Lundsten, Sara, 1992- (author) Searching for Synergy : Radiosensitization of 177Lu-DOTATATE 2022 Doctoral thesis (other academic/artistic)abstract Cancers presents a major health challenge, and there is a pressing need to develop new therapeutic strategies. Surgery, chemotherapy and radiation are the most commonly used treatments for cancer today. Radiation can be given as targeted radionuclide therapy (TRT), i.e., systemic administration of a radiolabeled cancer-targeting molecule. This is especially suitable for inoperable and disseminated tumors.177Lu-DOTATATE, a TRT directed against the somatostatin receptors (SSTRs), was recently approved for therapy of a subset of neuroendocrine tumors (NETs). Although it has prolonged the life of NET patients, complete remission is seldom achieved. Consequently, to increase the efficacy of the treatment, this thesis aimed to assess potential radiosensitizing strategies for 177Lu-DOTATATE. The two radiosensitization targets in focus were HSP90, a chaperone protein with numerous oncogenic client proteins, and p53, a central regulator of DNA damage.In papers I and II, we investigated the HSP90-inhibitor Onalespib, as a treatment for NETs, and as a potential radiosensitizer. The drugs were assessed in vitro and in vivo. We concluded that Onalespib reduced NET cell growth and acted synergistically with 177Lu-DOTATATE. Inhibition of EGFR, a HSP90 client protein, was suggested as a mediator of the observed synergy. Furthermore, the combination had a favorable toxicity profile. In paper III, we assessed the novel stapled peptide VIP116, which inhibits the p53 repressors MDM2 and MDM4, as a potentiator of 177Lu-DOTATATE in wildtype p53 neuroblastoma cells. Combination therapy exhibited growth-inhibitory effects, with resulting additive or synergistic effects. The treatment-mediated effects on p53 signaling were characterized, revealing a possible involvement of V-myc myelocytomatosis viral oncogene homolog, neuroblastoma derived (MYCN), a prognostic marker for poor survival in neuroblastoma.In paper IV, we aimed to improve targeted delivery of VIP116, with the use of lipid bilayer disks (lipodisks). VIP116 was successfully loaded onto epidermal growth factor receptor (EGFR)-targeting lipodisks, leading to specific delivery and reduction of viability of EGFR expressing tumor cells. The study provided a proof-of-concept for utilizing lipodisks as a drug delivery system for p53-stabilizing peptides.In conclusion, we have investigated, and found, suitable candidates for potentiating 177Lu-DOTATATE therapy. We have addressed the feasibility of the treatments, toxicity and targeted delivery. Moreover, the work has explored the biology of TRT. This is an area in need of more attention, as more and more radionuclide-based therapies are entering clinicals trials and reaching approval.
28.	Lundsten, Sara, et al. (author) The HSP90 inhibitor onalespib potentiates Lu-177-DOTATATE therapy in neuroendocrine tumor cells 2019 In: International Journal of Oncology. - : SPANDIDOS PUBL LTD. - 1019-6439 .- 1791-2423. ; 55:6, s. 1287-1295 Journal article (peer-reviewed)abstract Lu-177-DOTATATE was recently approved for the treatment of somatostatin receptor (SSTR)-positive neuroen-docrine tumors (NETs). However, despite impressive response rates, complete responses are rare. Heat shock protein 90 (HSP90) inhibitors have been suggested as suitable therapeutic agents for NETs, as well as a potential radiosensitizers. Consequently, the aim of this study was to investigate whether the HSP90-inhibitor onalespib could reduce NET cell growth and act as a radiosensitizer when used in combination with Lu-177-DOTATATE. The NET cell lines BON, NCI-H727 and NCI-H460, were first characterized with regards to Lu-177-DOTATATE uptake and sensitivity to onalespib treatment in monolayer cell assays. The growth inhibitory effects of the monotherapies and combination treatments were then examined in three-dimensional multicellular tumor spheroids. Lastly, the molecular effects of the treatments were assessed. Lu-177-DOTATATE uptake was observed in the BON and NCI-H727 cells, while the NCI-H460 cells exhibited no detectable uptake. Accordingly, Lu-177-DOTATATE reduced the growth of BON and NCI-H727 spheroids, while no effect was observed in the NCI-H460 spheroids. Onalespib reduced cell viability and spheroid growth in all three cell lines. Furthermore, the combination of onalespib and Lu-177-DOTATATE exerted synergistic therapeutic effects on the BON and NCI-H727 spheroids. Western blot analysis of BON spheroids revealed the downregulation of epidermal growth factor receptor (EGFR) and the upregulation of gamma H2A histone family member X (gamma H2AX) following combined treatment with onalespib and Lu-177-DOTATATE. Moreover, flow cytometric analyses revealed a two-fold increase in caspase 3/7 activity in the combination group. In conclusion, the findings of this study demonstrate that onalespib exerts antitumorigenic effects on NET cells and may thus be a feasible treatment option for NETs. Furthermore, onalespib was able to synergistically potentiate Lu-177-DOTATATE treatment in a SSTR-specific manner. The radiosensitizing mechanisms of onalespib involved the downregulation of EGFR expression and the induction of apoptosis. Consequently, the combination of onalespib and Lu-177-DOTATATE may prove to be a promising strategy with which to improve therapeutic responses in patients with NETs. Further studies investigating this strategy in vivo regarding the therapeutic effects and potential toxicities are warranted to expand these promising findings.
29.	Lundsten, Sara, et al. (author) The HSP90-inhibitor Onalespib Potentiates Lu-177-Dotatate Treatment of Neuroendocrine Tumors 2017 In: European Journal of Nuclear Medicine and Molecular Imaging. - : Springer. - 1619-7070 .- 1619-7089. ; 44, s. S326-S326 Journal article (other academic/artistic)
30.	Lundsten, Sara, et al. (author) The radiosensitizer Onalespib increases complete remission in Lu-177-DOTATATE-treated mice bearing neuroendocrine tumor xenografts 2020 In: European Journal of Nuclear Medicine and Molecular Imaging. - : SPRINGER. - 1619-7070 .- 1619-7089. ; 47:4, s. 980-990 Journal article (peer-reviewed)abstract Purpose: Lu-177-DOTATATE targeting the somatostatin receptor (SSTR) is utilized for treatment of neuroendocrine tumors (NETs). Onalespib, a heat shock protein 90 (HSP90) inhibitor, has demonstrated radiosensitizing properties and may thus enhance the effect of Lu-177-DOTATATE. Consequently, the aim of this study was to assess the potential of Onalespib in combination with Lu-177-DOTATATE in vivo and to examine the toxicity profiles of the treatments.Methods: Lu-177-DOTATATE selectivity and distribution in NET xenografts were studied using biodistribution and autoradiography. Therapeutic effects of Onalespib in combination with Lu-177-DOTATATE were studied in NET xenografts. Histological analyses were used to assess molecular effects from treatment and to establish toxicity profiles.Results: Biodistribution and autoradiography confirmed the SSTR-selective tumor uptake of Lu-177-DOTATATE, which was unaffected by Onalespib treatment. Immunohistochemistry verified molecular responses to Onalespib therapy in the tumors. While Onalespib and Lu-177-DOTATATE monotherapies resulted in a 10% and 33% delay in tumor doubling time compared with control, the combination treatment resulted in a 73% delayed tumor doubling time. Moreover, combination treatment increased complete remissions threefold from Lu-177-DOTATATE monotherapy, resulting in 29% complete remissions. In addition, histological analyses demonstrated radiation-induced glomerular injury in the Lu-177-DOTATATE monotherapy group. The damage was decreased tenfold in the combination group, potentially due to Onalespib-induced HSP70 upregulation in the kidneys.Conclusion: Treatment with Onalespib potentiated Lu-177-DOTATATE therapy of NET xenografts with a favorable toxicity profile. Utilizing Onalespib's radiosensitizing properties with Lu-177-DOTATATE may lead to better therapeutic results in the future and may reduce unwanted side effects in dose-limiting organs.
31.	Lundsten, Sara, et al. (author) Tumor-Targeted Delivery of the p53-Activating Peptide VIP116 with PEG-Stabilized Lipodisks 2020 In: Nanomaterials. - : MDPI AG. - 2079-4991. ; 10:4 Journal article (peer-reviewed)abstract Stapled peptides targeting the interaction between p53 and its negative regulators MDM2 and MDM4 have exhibited great potential as anti-cancer drugs, albeit with room for improvement in formulation and tumor specificity. Lipid bilayer disks (lipodisks) have emerged as promising drug nanocarriers and can by attachment of targeting moieties be directed selectively towards tumor cells. Tumor-targeted delivery of stapled peptides by use of lipodisks may therefore increase the uptake in the tumors and limit toxicity in healthy tissue. Here, we utilized epidermal growth factor receptor (EGFR)-targeted lipodisks to deliver p53-activating stapled peptide VIP116 to EGFR-expressing tumor cells. We demonstrate that VIP116 can be stably formulated in lipodisks (maximum peptide/lipid molar ratio 0.11). In vitro cell studies verify specific binding of EGF-decorated lipodisks to tumor cells and confirm that targeted delivery of VIP116 significantly decreases tumor cell viability.
32.	Mohajershojai, Tabassom, et al. (author) Enhanced Therapeutic Effects of 177Lu-DOTA-M5A in Combination with Heat Shock Protein 90 Inhibitor Onalespib in Colorectal Cancer Xenografts 2023 In: Cancers. - : MDPI. - 2072-6694. ; 15:17 Journal article (peer-reviewed)abstract Carcinoembryonic antigen (CEA) has emerged as an attractive target for theranostic applications in colorectal cancers (CRCs). In the present study, the humanized anti-CEA antibody hT84.66-M5A (M5A) was labeled with 177Lu for potential CRC therapy. Moreover, the novel combination of 177Lu-DOTA-M5A with the heat shock protein 90 inhibitor onalespib, suggested to mediate radiosensitizing properties, was assessed in vivo for the first time. M5A antibody uptake and therapeutic effects, alone or in combination with onalespib, were assessed in human CRC xenografts and visualized using SPECT/CT imaging. Although both 177Lu-DOTA-M5A and onalespib monotherapies effectively reduced tumor growth rates, the combination therapy demonstrated the most substantial impact, achieving a fourfold reduction in tumor growth compared to the control group. Median survival increased by 33% compared to 177Lu-DOTA-M5A alone, and tripled compared to control and onalespib groups. Importantly, combination therapy yielded comparable or superior effects to the double dose of 177Lu-DOTA-M5A monotherapy. 177Lu-DOTA-M5A increased apoptotic cell levels, indicating its potential to induce tumor cell death. These findings show promise for 177Lu-DOTA-M5A as a CRC therapeutic agent, and its combination with onalespib could significantly enhance treatment efficacy. Further in vivo studies are warranted to validate these findings fully and explore the treatment’s potential for clinical use.Simple summaryCancer treatment is hampered by the limitations of individual therapy modalities and the intricate nature of the disease. The administration of maximal monotherapy doses often leads to undesirable side effects and/or therapy resistance. As a result, there is a growing recognition of the importance of investigating combination therapy to effectively address these obstacles. In the present in vivo study, the therapeutic effects of combination therapy with the heat shock protein 90 inhibitor onalespib, a potential radiosensitizer, and 177Lu-DOTA-M5A for colorectal cancer (CRC) treatment were explored for the first time. The results demonstrated that the combination treatment was so effective that retained or even superior therapeutic effects could be achieved with only half the dose of administered 177Lu-DOTA-M5A, showing enhanced tumor growth suppression and increased apoptosis. Consequently, the combination therapy involving 177Lu-DOTA-M5A and onalespib constitutes a promising approach for treating metastatic CRCs. By enhancing therapeutic effects, minimizing therapy resistance, and reducing side effects, this approach has the potential to expand the patient population that can benefit from targeted treatment.
33.	Mohajershojai, Tabassom, et al. (author) In Vitro Characterization of Lu-177-DOTA-M5A Anti-Carcinoembryonic Antigen Humanized Antibody and HSP90 Inhibition for Potentiated Radioimmunotherapy of Colorectal Cancer 2022 In: Frontiers in Oncology. - : Frontiers Media S.A.. - 2234-943X. ; 12 Journal article (peer-reviewed)abstract Carcinoembryonic antigen (CEA) is an antigen that is highly expressed in colorectal cancers and widely used as a tumor marker. I-131 and Y-90-radiolabeled anti-CEA monoclonal antibodies (mAbs) have previously been assessed for radioimmunotherapy in early clinical trials with promising results. Moreover, the heat shock protein 90 inhibitor onalespib has previously demonstrated radiotherapy potentiation effects in vivo. In the present study, a Lu-177-radiolabeled anti-CEA hT84.66-M5A mAb (M5A) conjugate was developed and the potential therapeutic effects of Lu-177-DOTA-M5A and/or onalespib were investigated. The Lu-177 radiolabeling of M5A was first optimized and characterized. Binding specificity and affinity of the conjugate were then evaluated in a panel of gastrointestinal cancer cell lines. The effects on spheroid growth and cell viability, as well as molecular effects from treatments, were then assessed in several three-dimensional (3D) multicellular colorectal cancer spheroid models. Stable and reproducible radiolabeling was obtained, with labeling yields above 92%, and stability was retained at least 48 h post-radiolabeling. Antigen-specific binding of the radiolabeled conjugate was demonstrated on all CEA-positive cell lines. Dose-dependent therapeutic effects of both Lu-177-DOTA-M5A and onalespib were demonstrated in the spheroid models. Moreover, effects were potentiated in several dose combinations, where spheroid sizes and viabilities were significantly decreased compared to the corresponding monotherapies. For example, the combination treatment with 350 nM onalespib and 20 kBq Lu-177-DOTA-M5A resulted in 2.5 and 2.3 times smaller spheroids at the experimental endpoint than the corresponding monotreatments in the SNU1544 spheroid model. Synergistic effects were demonstrated in several of the more effective combinations. Molecular assessments validated the therapy results and displayed increased apoptosis in several combination treatments. In conclusion, the combination therapy of anti-CEA Lu-177-DOTA-M5A and onalespib showed enhanced therapeutic effects over the individual monotherapies for the potential treatment of colorectal cancer. Further in vitro and in vivo studies are warranted to confirm the current study findings.
34.	Mohajershojai, Tabassom, et al. (author) PD-1 blockade enhances therapeutic effects of 177Lu-DOTA-M5A in colorectal cancer CEA-transgenic mice Other publication (other academic/artistic)abstract Radioimmunotherapy (RIT) is emerging as an effective treatment for metastatic solid tumors by coupling radionuclides with tumor-targeting molecules, precisely directing radiation to cancer cells while sparing healthy tissue. Carcinoembryonic antigen (CEA) is a promising target for RIT in CEA-expressing cancers, including colorectal cancers (CRCs). Recent studies highlight radiotherapy's role in enhancing the immune response against cancer. Combining RIT with immune checkpoint inhibitors, such as anti-PD-1 antibodies, may further enhance anti-tumor immunity and improve outcomes. This study aimed to investigate, for the first time, the in vivo effects of CEA-targeted RIT using the novel humanized anti-CEA antibody hT84.66-M5A labeled with 177Lu (177Lu-DOTA-M5A), combined with PD-1 blockade. Radioconjugate uptake and therapeutic effects were first assessed in vitro using the CRC spheroid model MC38-CEA1. The therapeutic effects of 177Lu-DOTA-M5A and PD-1 blockade were then evaluated alone or in combination in CEA-transgenic mice bearing CEA-transduced CRC xenografts, with radioconjugate uptake validated in biodistribution studies and visualized via SPECT/CT imaging. Dose-dependent therapeutic effects of 177Lu-DOTA-M5A were demonstrated in the 3D spheroid model. In vivo studies showed that both 177Lu-DOTA-M5A and PD-1 antibody monotherapies effectively reduced tumor growth rates compared to the control group, but the combination therapy had the most significant impact. Combination therapy resulted in a dramatic tumor growth inhibition rate of -6% average daily, compared to +7%, +7.9%, and +13.5% in the PD-1 blockade, 177Lu-DOTA-M5A (2.5 MBq), and control groups, respectively. Median survival increased by 31% in the PD-1 blockade group and by 52% in the 177Lu-DOTA-M5A (2.5 MBq) group compared to the control group, while median survival was not reached in the corresponding combination group. Radioconjugate monotherapies and combination therapies did not introduce any bone marrow toxicity. 177Lu-DOTA-M5A slightly altered the immune cell profile in the tumor microenvironment, increasing cytotoxic and helper T cells. Notably, pro-inflammatory macrophages became dominant over tumor-promoting ones in the tumor microenvironment of combination-treated mice. These findings highlight the promise of 177Lu-DOTA-M5A as a CRC therapeutic agent and its enhanced efficacy when combined with an immune checkpoint inhibitor. Further in vivo studies are needed to fully validate these findings and explore the treatment’s potential for clinical use.
35.	Mortensen, Anja C., et al. (author) Enhancing therapeutic effects of radio-immunotherapy using the novel stapled MDM2/X-p53 antagonist PM2 Other publication (other academic/artistic)
36.	Mortensen, Anja C., et al. (author) In Vivo Assessment of p53 Therapy as a Way of Enhancing Therapeutic Effects of Radiation 2017 In: European Journal of Nuclear Medicine and Molecular Imaging. - : Springer. - 1619-7070 .- 1619-7089. ; 44, s. S181-S181 Journal article (other academic/artistic)
37.	Mortensen, Anja C., et al. (author) The Novel, Stapled HDM2/HDMX-p53 Antagonist PM2 Has Potent Antitumorigenic Activities and Enhances the Effects of External Radiotherapy 2017 In: European Journal of Nuclear Medicine and Molecular Imaging. - : Springer. - 1619-7070 .- 1619-7089. ; 44, s. S562-S562 Journal article (other academic/artistic)
38.	Mortensen, Anja, et al. (author) Enhancing the therapeutic effects of in vitro targeted radionuclide therapy of 3D multicellular tumor spheroids using the novel stapled MDM2/X-p53 antagonist PM2 2020 In: EJNMMI Research. - : SPRINGER. - 2191-219X. ; 10 Journal article (peer-reviewed)abstract Background: Precision therapeutics continuously make advances in cancer therapy, and a field of growing interest is the combination of targeted radionuclide therapy (TRNT) with potential radiosensitizing agents. This study evaluated whether the effects of in vitro TRNT, using the Lu-177-labeled anti-CD44v6 antibody AbN44v6, were potentiated by the novel stapled MDM2/X-p53 antagonist PM2.Materials and methods: Two wt p53 cell lines, HCT116 (colorectal carcinoma) and UM-SCC-74B (head and neck squamous cell carcinoma), expressing different levels of the target antigen, CD44v6, were used. Antigen-specific binding of Lu-177-AbN44v6 was initially verified in a 2D cell assay, after which the potential effects of unlabeled AbN44v6 on downstream phosphorylation of Erk1/2 were evaluated by western blotting. Further, the therapeutic effects of unlabeled AbN44v6, Lu-177-AbN44v6, PM2, or a combination (labeled/unlabeled AbN44v6 +/- PM2) were assessed in 3D multicellular tumor spheroid assays.Results: Radiolabeled antibody bound specifically to CD44v6 on both cell lines. Unlabeled AbN44v6 binding did not induce downstream phosphorylation of Erk1/2 at any of the concentrations tested, and repeated treatments with the unlabeled antibody did not result in any spheroid growth inhibition. Lu-177-AbN44v6 impaired spheroid growth in a dose-dependent and antigen-dependent manner. A single modality treatment with 20 mu M of PM2 significantly impaired spheroid growth in both spheroid models. Furthermore, the combination of TRNT and PM2-based therapy proved significantly more potent than either monotherapy. In HCT116 spheroids, this resulted in a two- and threefold spheroid growth rate decrease for the combination of PM2 and 100 kBq Lu-177-AbN44v6 compared to monotherapies 14-day post treatment. In UM-SCC-74B spheroids, the combination therapy resulted in a reduction in spheroid size compared to the initial spheroid size 10-day post treatment.Conclusion: TRNT using Lu-177-AbN44v6 proved efficient in stalling spheroid growth in a dose-dependent and antigen-dependent manner, and PM2 treatment demonstrated a growth inhibitory effect as a monotherapy. Moreover, by combining TRNT with PM2-based therapy, therapeutic effects of TRNT were potentiated in a 3D multicellular tumor spheroid model. This proof-of-concept study exemplifies the strength and possibility of combining TRNT targeting CD44v6 with PM2-based therapy.
39.	Mortensen, Anja, et al. (author) Preclinical evaluation of a novel engineered recombinant human anti-CD44v6 antibody for potential use in radio-immunotherapy 2018 In: International Journal of Oncology. - : Spandidos Publications. - 1019-6439 .- 1791-2423. ; 52:6, s. 1875-1885 Journal article (peer-reviewed)abstract CD44v6 is overexpressed in a variety of cancers, rendering it a promising target for radio-immunotherapy (RIT). In this study, we have characterized a novel engineered recombinant monoclonal anti-CD44v6 antibody, AbN44v6, and assessed its potential for use in RIT using either Lu-177 or I-131 as therapeutic radionuclides. In vitro affinity and specificity assays characterized the binding of the antibody labeled with Lu-177, I-125 or I-131. The therapeutic effects of Lu-177-AbN44v6 and I-131-AbN44v6 were investigated using two in vitro 3D tumor models with different CD44v6 expression. Finally, the normal tissue biodistribution and dosimetry for Lu-177-AbN44v6 and I-125-AbN44v6/I-131-AbN44v6 were assessed in vivo using a mouse model. All AbN44v6 radioconjugates demonstrated CD44v6-specific binding in vitro. In the in vitro 3D tumor models, dose-dependent therapeutic effects were observed with both Lu-177-AbN44v6 and I-131-AbN44v6, with a greater significant therapeutic effect observed on the cells with a higher CD44v6 expression. Biodistribution experiments demonstrated a greater uptake of Lu-177-AbN44v6 in the liver, spleen and bone, compared to I-125-AbN44v6, whereas I-125-AbN44v6 demonstrated a longer circulation time. In dosimetric calculations, the critical organs for Lu-177-AbN44v6 were the liver and spleen, whereas the kidneys and red marrow were considered the critical organs for I-131-AbN44v6. The effective dose was in the order of 0.1 mSv/MBq for both labels. In conclusion, AbN44v6 bound specifically and with high affinity to CD44v6. Furthermore, in vitro RIT demonstrated growth inhibition in a CD44v6-specific activity-dependent manner for both radioconjugates, demonstrating that both Lu-177-AbN44v6 and I-131-AbN44v6 may be promising RIT candidates. Furthermore, biodistribution and dosimetric analysis supported the applicability of both conjugates for RIT. The CD44v6-specific therapeutic effects observed with radiolabeled AbN44v6 in the 3D tumor models in vitro, combined with the beneficial dosimetry in vivo, render AbN44v6 a potential candidate for RIT.
40.	Mortensen, Anja, et al. (author) Selection, characterization and in vivo evaluation of novel CD44v6-targeting antibodies for targeted molecular radiotherapy 2023 In: Scientific Reports. - : Springer Nature. - 2045-2322. ; 13:1 Journal article (peer-reviewed)abstract Molecular radiotherapy combines the advantages of systemic administration of highly specific antibodies or peptides and the localized potency of ionizing radiation. A potential target for molecular radiotherapy is the cell surface antigen CD44v6, which is overexpressed in numerous cancers, with limited expression in normal tissues. The aim of the present study was to generate and characterize a panel of human anti-CD44v6 antibodies and identify a suitable candidate for future use in molecular radiotherapy of CD44v6-expressing cancers. Binders were first isolated from large synthetic phage display libraries containing human scFv and Fab antibody fragments. The antibodies were extensively analyzed through in vitro investigations of binding kinetics, affinity, off-target binding, and cell binding. Lead candidates were further subjected to in vivo biodistribution studies in mice bearing anaplastic thyroid cancer xenografts that express high levels of CD44v6. Additionally, antigen-dependent tumor uptake of the lead candidate was verified in additional xenograft models with varying levels of target expression. Interestingly, although only small differences were observed among the top antibody candidates in vitro, significant differences in tumor uptake and retention were uncovered in in vivo experiments. A high-affinity anti-CD44v6 lead drug candidate was identified, mAb UU-40, which exhibited favorable target binding properties and in vivo distribution. In conclusion, a panel of human anti-CD44v6 antibodies was successfully generated and characterized in this study. Through comprehensive evaluation, mAb UU-40 was identified as a promising lead candidate for future molecular radiotherapy of CD44v6-expressing cancers due to its high affinity, excellent target binding properties, and desirable in vivo distribution characteristics.
41.	Mortensen, Anja, et al. (author) Utilizing CD44v6 and V600EBRAF-mutation for in vitro targeted combination therapy of thyroid carcinomas 2023 In: Heliyon. - : Cell Press. - 2405-8440. ; 9:12 Journal article (peer-reviewed)abstract Aim: The aim of this study was to assess the feasibility of targeted therapy of thyroid carcinoma, first exploring potential targets BRAF, EGFR and CD44v6 in patient material through immunohistochemistry and mutation analysis.Materials and methods: A patient cohort (n = 22) consisting of seven papillary (PTC), eight anaplastic (ATC) and seven follicular (FTC) thyroid carcinomas were evaluated. Additionally, eight thyroid carcinoma cells lines were analyzed for CD44v6-expression and sensitivity to the multi-kinase inhibitor sorafenib (Nexavar (R)), which targets numerous serine/threonine and tyrosine kinases, including the Raf family kinases. Targeted therapy using 131I-AbN44v6, a novel anti-CD44v6 antibody, and/or sorafenib was evaluated in 3D multicellular tumor spheroids. RResults: Of the two cell surface proteins, EGFR and CD44v6, the latter was overexpressed in >80 % of samples, while EGFR-expression levels were moderate at best in only a few samples. BRAF mutations were more common in PTC patient samples than in ATC samples, while FTC samples did not harbor BRAF mutations. CD44v6-expression levels in the thyroid carcinoma cell lines were more heterogenous compared to patient samples, while BRAF mutational status was in line with the original tumor type. Monotherapy in 3D multicellular ATC tumor spheroids with either 131I-AbN44v6 or sorafenib resulted in delayed spheroid growth. The combination of 131I-AbN44v6 and sorafenib was the most potent and resulted in significantly impaired spheroid growth.Conclusion: This "proof of concept" targeted therapy study in the in vitro ATC 3D multicellular tumor spheroids indicated applicability of utilizing CD44v6 for molecular radiotherapy both as a monotherapy and in combination with sorafenib.
42.	Nestor, Marika, 1976- (author) Antibody-Based Radionuclide Targeting for Diagnostics and Therapy : Preclinical Studies on Head and Neck Cancer 2006 Doctoral thesis (other academic/artistic)abstract Antibody-based targeting techniques play an increasingly important role in cancer research. By targeting a structure that is abundant in tumour cells, but rare in healthy tissues, an antibody can mediate the delivery of radioactivity specifically to tumour cells in the body. This idea is particularly appealing for head and neck squamous cell carcinoma (HNSCC), as the advanced stages have a large fraction of spread disease that is difficult to treat with procedures available today. In this thesis, we have investigated possible radioimmunotargeting structures for HNSCC, and found that CD44v6 is a suitable target for antibody-based radiotherapy and diagnostics in this patient group. We have identified radiohalogens as attractive nuclides for such use, and have investigated the possibility of radiohalogenating the anti CD44v6 chimeric monoclonal antibody (cMAb) U36. Several feasible labelling methods were identified, using both direct and indirect labelling. The cMAb U36 was then successfully labelled with 211At and 131I, and preclinically evaluated for therapeutic use. Results proved the astatinated conjugate to be most efficient in this context, demonstrating a specific and dose-dependent cytotoxicity. The cMAb U36 was then evaluated for diagnostic use in thyroid anaplastic carcinoma, using 124I as the diagnostic nuclide. Results in tumour-bearing mice were promising, with all of the tumours identified in micro-PET studies. These results demonstrate how antibody-based radionuclide targeting can provide more sensitive and specific methods for identifying and treating head and neck cancer, and hopefully help improve long-term survival rates for this patient group in the future.
43.	Sandström, Karl, et al. (author) A novel CD44v6 targeting antibody fragment with improved tumor-to-blood ratio 2012 In: International Journal of Oncology. - : Spandidos Publications. - 1019-6439 .- 1791-2423. ; 40:5, s. 1525-1532 Journal article (peer-reviewed)abstract The chimeric monoclonal antibody U36 (cMAb U36) recognizes the CD44v6 antigen. Its potential as a radioimmunotargeting agent, as well as its safety, has been shown in previous studies in head and neck cancer patients. However, intact MAbs have long circulation time in the blood and tumor targeting may also be hampered due to the slow and incomplete diffusion into solid tumors. In comparison, smaller monovalent Fab' and divalent F(ab')2 fragments are expected to exhibit shorter circulating half-lives, better tumor penetration and are thus more likely to yield better imaging results. In this study, novel F(ab')2 and Fab' fragments from cMAb U36 were radiolabeled with 125I and the characteristics of the conjugates in vitro were examined. The biodistribution of the conjugates were then evaluated in nude mice bearing CD44v6-expressing xenograft tumors. Furthermore, the penetration depth and distribution in tumor tissue was assessed by autoradiography in selected tumor samples. The in vitro experiments showed that the conjugates were stable and had intact affinity to CD44v6. The biodistribution study demonstrated superior tumor-to-blood ratio for the novel cMAb U36 fragment 125I-F(ab')2 compared with both the intact MAb and the monovalent fragment form. Autoradiography also revealed better tumor penetration for 125I-F(ab')2. This study demonstrates that the use of antibody fragments may improve radioimmunotargeting and possibly improve the management of head and neck malignancies.
44.	Sarén, Tina, et al. (author) Complementarity-determining region clustering may cause CAR-T cell dysfunction 2023 In: Nature Communications. - : Springer Nature. - 2041-1723. ; 14:1, s. 4732- Journal article (peer-reviewed)abstract Chimeric antigen receptor (CAR)-T cell therapy is rapidly advancing as cancer treatment, however, designing an optimal CAR remains challenging. A single-chain variable fragment (scFv) is generally used as CAR targeting moiety, wherein the complementarity-determining regions (CDRs) define its specificity. We report here that the CDR loops can cause CAR clustering, leading to antigen-independent tonic signalling and subsequent CAR-T cell dysfunction. We show via CARs incorporating scFvs with identical framework and varying CDR sequences that CARs may cluster on the T cell surface, which leads to antigen-independent CAR-T cell activation, characterized by increased cell size and interferon (IFN)-γ secretion. This results in CAR-T cell exhaustion, activation-induced cell death and reduced responsiveness to target-antigen-expressing tumour cells. CDR mutagenesis confirms that the CAR-clustering is mediated by CDR-loops. In summary, antigen-independent tonic signalling can be induced by CDR-mediated CAR clustering, which could not be predicted from the scFv sequences, but could be tested for by evaluating the activity of unstimulated CAR-T cells.
45.	Spiegelberg, Diana, et al. (author) A real-time in vitro assay as a potential predictor of in vivo tumor imaging properties 2016 In: Nuclear Medicine and Biology. - : Elsevier BV. - 0969-8051 .- 1872-9614. ; 43:1, s. 12-18 Journal article (peer-reviewed)abstract Introduction: Selective tumor targeting strategies based on cell surface molecules enable new personalized diagnosis and treatments, potentially lowering adverse effects and increasing efficacy. Radio-immunotargeting generally relies on a molecule binding to a cancer-specific target. It is therefore important to understand the properties of molecular interactions in their working environment and how to translate these properties measured in vitro into the in vivo molecular imaging situation. Methods: Time resolved interaction analysis in vitro was compared with a corresponding in vivo xenograft mouse model. The antibody fragment AbD15179 was labeled with I-125 or In-111, and analyzed on cell lines with differing CD44v6 expression in vitro, and in a dual tumor xenograft model derived from the same cell lines. In vitro LigandTracer measurements were analyzed with TraceDrawer and Interaction Map. Conjugate sensitivity, kinetics, and signal-to-background ratios were assessed for both tumor cells in vitro and xenograft tumors in vivo. Results: In vitro results revealed a general biphasic appearance of a high- and a low-affinity interaction event. The In-111-labeled fragment displayed the largest proportion of the high-affinity interaction with increased sensitivity and retention compared to I-125-Fab. In vivo results were in agreement with in vitro data, with increased retention, higher sensitivity and better contrast for the In-111-labeled fragment compared to I-125. Conclusions: Time resolved binding characteristics measured in vitro largely matched the in vivo performance for the conjugates, which is promising for future studies. In vitro time-resolved LigandTracer assays are efficient, rapid, and in this study shown to be able to predict in vivo outcomes. Advances in Knowledge and Implications for Patient Care: Further studies are needed to confirm these findings, but the method is promising considering the ethical need to reduce the use of laboratory animals, as well as reducing costs for the development of tumor targeting compounds in the future.
46.	Spiegelberg, Diana, et al. (author) Characterization of CD44 variant expression in head and neck squamous cell carcinomas 2014 In: Tumor Biology. - : Springer Science and Business Media LLC. - 1010-4283 .- 1423-0380. ; 35:3, s. 2053-2062 Journal article (peer-reviewed)abstract CD44 is a complex family of molecules, associated with aggressive malignancies and cancer stem cells. However, the role of CD44 variants in tumor progression and treatment resistance is not clear. In this study, the expression of CD44 and its variants was assessed in head and neck squamous cell carcinomas (HNSCC). Furthermore, subpopulations of cells expressing high amounts of CD44 variants were identified and characterized, for e.g., cell cycle phase and radioresistance. Results revealed high and homogenous CD44 and CD44v7 expression in four cell lines and CD44v4 and CD44v6 in three cell lines. CD44v3 was highly expressed in two cell lines, whereas CD44v5, CD44v7/8, CD44v10, CD133, and CD24 demonstrated no or moderate expression. Moreover, a subpopulation of very high CD44v4 expression was identified, which is independent of cell phase, demonstrating increased proliferation and radioresistance. In cell starvation experiments designed to enrich for cancer stem cells, a large population with dramatically increased expression of CD44, CD44v3, CD44v6, and CD44v7 was formed. Expression was independent of cell phase, and cells demonstrated increased radioresistance and migration rate. Our results demonstrate that the heterogeneity of tumor cells has important clinical implications for the treatment of HNSCC and that some of the CD44 variants may be associated with increased radioresistance. Highly expressed CD44 variants could make interesting candidates for selective cancer targeting.
47.	Spiegelberg, Diana, 1982-, et al. (author) First in vivo study of the MDM2/MDMX-p53 antagonist PM2 as potentiator of external radiotherapy in wt p53 cancer 2018 In: European Journal of Nuclear Medicine and Molecular Imaging. - : Springer Science and Business Media LLC. - 1619-7070 .- 1619-7089. ; 45:Supplement: 1, s. S30-S30 Journal article (other academic/artistic)
48.	Spiegelberg, Diana, 1982-, et al. (author) In Vitro and In Vivo Growth Inhibitory and Radiosensitizing Effects of the Anti-HSP90 agent Onalespib 2017 In: European Journal of Nuclear Medicine and Molecular Imaging. - : Springer. - 1619-7070 .- 1619-7089. ; 44, s. S182-S182 Journal article (other academic/artistic)
49.	Spiegelberg, Diana, 1982-, et al. (author) The HSP90 inhibitor Onalespib exerts synergistic anti-cancer effects when combined with radiotherapy : an in vitro and in vivo approach 2020 In: Scientific Reports. - : NATURE PUBLISHING GROUP. - 2045-2322. ; 10:1 Journal article (peer-reviewed)abstract Oncogenic client-proteins of the chaperone Heat shock protein 90 (HSP90) insure unlimited tumor growth and are involved in resistance to chemo- and radiotherapy. The HSP90 inhibitor Onalespib initiates the degradation of oncoproteins, and might also act as a radiosensitizer. The aim of this study was therefore to evaluate the efficacy of Onalespib in combination with external beam radiotherapy in an in vitro and in vivo approach. Onalespib downregulated client proteins, lead to increased apoptosis and caused DNA-double-strands. Monotherapy and combination with radiotherapy reduced colony formation, proliferation and migration assessed in radiosensitive HCT116 and radioresistant A431 cells. In vivo, a minimal treatment regimen for 3 consecutive days of Onalespib (3 x 10 mg/kg) doubled survival, whereas Onalespib with radiotherapy (3 x 2 Gy) caused a substantial delay in tumor growth and prolonged the survival by a factor of 3 compared to the HCT116 xenografted control group. Our results demonstrate that Onalespib exerts synergistic anti-cancer effects when combined with radiotherapy, most prominent in the radiosensitive cell models. We speculate that the depletion and downregulation of client proteins involved in signalling, migration and DNA repair mechanisms is the cause. Thus, individually, or in combination with radiotherapy Onalespib inhibits tumor growth and has the potential to improve radiotherapy outcomes, prolonging the overall survival of cancer patients.
50.	Spiegelberg, Diana, 1982-, et al. (author) The MDM2/MDMX-p53 Antagonist PM2 Radiosensitizes Wild-Type p53 Tumors 2018 In: Cancer Research. - : AMER ASSOC CANCER RESEARCH. - 0008-5472 .- 1538-7445. ; 78:17, s. 5084-5093 Journal article (peer-reviewed)abstract Radiotherapy amplifies p53 expression in cancer cells with wild-type (wt) p53. Blocking the negative regulators MDM2 and MDMX stabilizes p53 and may therefore potentiate radiotherapy outcomes. In this study, we investigate the efficacy of the novel anti-MDM2/X stapled peptide PM2 alone and in combination with externalgamma radiation in vitro and in vivo. PM2 therapy combined with radiotherapy elicited synergistic therapeutic effects compared with monotherapy in cells with wt p53 in both in vitro and in vivo assays, whereas these effects did not manifest in p53(-/-) cells. Biodistribution and autoradiography of 125I-PM2 revealed high and retained uptake homogenously distributed throughout the tumor. In mice carrying wt p53 tumors, PM2 combined with radiother-apy significantly prolonged the median survival by 50%, whereas effects of PM2 therapy on mutant and p53(-/-) tumors were negligible. PM2-dependent stabilization of p53 was confirmed with ex vivo immunohistochemistry. These data demonstrate the potential of the stapled peptide PM2 as a radiotherapy potentiator in vivo and suggest that clinical application of PM2 with radiotherapy in wt p53 cancers might improve tumor control.Significance: These findings contribute advances to cancer radiotherapy by using novel p53-reactivating stapled peptides as radiosensitizers in wild-type p53 cancers.

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Author/Editor: Nestor, Marika, 1976 ... (50); Spiegelberg, Diana, ... (19); Lundsten, Sara (14); Lane, David P. (10); Mortensen, Anja (9); Stenerlöw, Bo (5); show more...; Mohajershojai, Tabas ... (5); Brown, Christopher J ... (5); Haylock, Anna-Karin (5); Mortensen, Anja C. (5); Jha, Preeti (4); Pettersson, Curt (4); Sarmento, Bruno (4); Spiegelberg, Diana (4); Edwards, Katarina (3); Brown, C (3); Haglöf, Jakob (3); Arvidsson, Torbjörn (3); Hedeland, Mikael (3); Frejd, Fredrik Y. (3); Buijs, Jos (3); Berglund, Hanna (3); Bondza, Sina (3); Erngren, Ida (3); Lane, David Philip (3); Lundqvist, Hans (2); Ferreira, Daniel (2); Krona, Cecilia, 1976 (2); Abramenkovs, Andris (2); Nelander, Sven (2); Nilvebrant, Johan (2); Morin, Eric (2); Sandström, Karl (2); Persson, Helena (2); Wermeling, Fredrik (2); Björkelund, Hanna, 1 ... (2); ten Broeke, Toine (2); Chandramohan, Arun (2); Partridge, Anthony W ... (2); Engskog, Mikael K R (2); Oliveira, Carla (2); Hofström, Camilla (2); Spangler, Douglas (2); Ingelshed, Katrine (2); Kannan, Pavitra (2); Jiang, Long (2); Kennedy, Patrick J. (2); Granja, Pedro L. (2); Raval, Nakul (2); Sarén, Tina (2); show less...

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