| 1. |
- All-Ericsson, Charlotta, et al.
(författare)
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c-Kit-dependent growth of uveal melanoma cells : a potential therapeutic target?
- 2004
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Ingår i: Investigative Ophthalmology and Visual Science. - : Association for Research in Vision and Ophthalmology (ARVO). - 0146-0404 .- 1552-5783. ; 45:7, s. 2075-82
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Tidskriftsartikel (refereegranskat)abstract
- PURPOSE: This study was conducted to investigate the expression and functional impact of the proto-oncogene c-kit in uveal melanoma. METHODS: Based on immunohistochemical (IHC) study of paraffin-embedded specimens from 134 uveal melanomas and Western blot analysis on eight fresh-frozen samples the expression of c-kit in uveal melanoma was studied. Furthermore, the phosphorylation of c-kit and the impact of the tyrosine kinase inhibitor STI571 was examined in the three uveal melanoma cell lines OCM-1, OCM-3, and 92-1. RESULTS: Eighty-four of 134 paraffin-embedded samples and six of eight fresh-frozen samples expressed c-kit. c-Kit was strongly expressed and tyrosine phosphorylated in cultured uveal melanoma cells compared with cutaneous melanoma cells. Moreover, in contrast to cutaneous melanoma cell lines c-kit maintained a high phosphorylation level in serum-depleted uveal melanoma cells. No activation-related mutations in exon 11 of the KIT gene were found. On the contrary, expression of the stem cell growth factor (c-kit ligand) was detected in all three uveal melanoma cell lines, suggesting the presence of autocrine (paracrine) stimulation pathways. Treatment of uveal melanoma cell lines with STI571, which blocks c-kit autophosphorylation, resulted in cell death. The IC(50) of the inhibitory effects on c-kit phosphorylation and cell proliferation was of equal size and less than 2.5 microM. CONCLUSIONS: The results confirm that c-kit is vastly expressed in uveal melanoma, suggest that the c-kit molecular pathway may be important in uveal melanoma growth, and point to its use as a target for therapy with STI571.
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| 2. |
- Arsana, Komang G.Y., et al.
(författare)
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Laboratory Liquid-Jet X-ray Microscopy and X-ray Fluorescence Imaging for Biomedical Applications
- 2024
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Ingår i: International Journal of Molecular Sciences. - : MDPI AG. - 1661-6596 .- 1422-0067. ; 25:2
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Tidskriftsartikel (refereegranskat)abstract
- Diffraction-limited resolution and low penetration depth are fundamental constraints in optical microscopy and in vivo imaging. Recently, liquid-jet X-ray technology has enabled the generation of X-rays with high-power intensities in laboratory settings. By allowing the observation of cellular processes in their natural state, liquid-jet soft X-ray microscopy (SXM) can provide morphological information on living cells without staining. Furthermore, X-ray fluorescence imaging (XFI) permits the tracking of contrast agents in vivo with high elemental specificity, going beyond attenuation contrast. In this study, we established a methodology to investigate nanoparticle (NP) interactions in vitro and in vivo, solely based on X-ray imaging. We employed soft (0.5 keV) and hard (24 keV) X-rays for cellular studies and preclinical evaluations, respectively. Our results demonstrated the possibility of localizing NPs in the intracellular environment via SXM and evaluating their biodistribution with in vivo multiplexed XFI. We envisage that laboratory liquid-jet X-ray technology will significantly contribute to advancing our understanding of biological systems in the field of nanomedical research.
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| 3. |
- Brodin, Bertha A., et al.
(författare)
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Drug sensitivity testing on patient-derived sarcoma cells predicts patient response to treatment and identifies c-Sarc inhibitors as active drugs for translocation sarcomas
- 2019
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Ingår i: British Journal of Cancer. - : Springer Science and Business Media LLC. - 0007-0920 .- 1532-1827. ; 120:4, s. 435-443
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Heterogeneity and low incidence comprise the biggest challenge in sarcoma diagnosis and treatment. Chemotherapy, although efficient for some sarcoma subtypes, generally results in poor clinical responses and is mostly recommended for advanced disease. Specific genomic aberrations have been identified in some sarcoma subtypes but few of them can be targeted with approved drugs. METHODS: We cultured and characterised patient-derived sarcoma cells and evaluated their sensitivity to 525 anti-cancer agents including both approved and non-approved drugs. In total, 14 sarcomas and 5 healthy mesenchymal primary cell cultures were studied. The sarcoma biopsies and derived cells were characterised by gene panel sequencing, cancer driver gene expression and by detecting specific fusion oncoproteins in situ in sarcomas with translocations. RESULTS: Soft tissue sarcoma cultures were established from patient biopsies with a success rate of 58%. The genomic profile and drug sensitivity testing on these samples helped to identify targeted inhibitors active on sarcomas. The cSrc inhibitor Dasatinib was identified as an active drug in sarcomas carrying chromosomal translocations. The drug sensitivity of the patient sarcoma cells ex vivo correlated with the response to the former treatment of the patient. CONCLUSIONS: Our results show that patient-derived sarcoma cells cultured in vitro are relevant and practical models for genotypic and phenotypic screens aiming to identify efficient drugs to treat sarcoma patients with poor treatment options.
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| 4. |
- Ehnman, Monika, et al.
(författare)
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Distinct Effects of Ligand-Induced PDGFR alpha and PDGFR beta Signaling in the Human Rhabdomyosarcoma Tumor Cell and Stroma Cell Compartments
- 2013
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Ingår i: Cancer Research. - 1538-7445. ; 73:7, s. 2139-2149
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Tidskriftsartikel (refereegranskat)abstract
- Platelet-derived growth factor receptors (PDGFR) alpha and beta have been suggested as potential targets for treatment of rhabdomyosarcoma, the most common soft tissue sarcoma in children. This study identifies biologic activities linked to PDGF signaling in rhabdomyosarcoma models and human sample collections. Analysis of gene expression profiles of 101 primary human rhabdomyosarcomas revealed elevated PDGF-C and -D expression in all subtypes, with PDGF-D as the solely overexpressed PDGFR beta ligand. By immunohistochemistry, PDGF-CC, PDGF-DD, and PDGFR alpha were found in tumor cells, whereas PDGFR beta was primarily detected in vascular stroma. These results are concordant with the biologic processes and pathways identified by data mining. While PDGF-CC/PDGFR alpha signaling associated with genes involved in the reactivation of developmental programs, PDGF-DD/PDGFR beta signaling related to wound healing and leukocyte differentiation. Clinicopathologic correlations further identified associations between PDGFR beta in vascular stroma and the alveolar subtype and with presence of metastases. Functional validation of our findings was carried out in molecularly distinct model systems, where therapeutic targeting reduced tumor burden in a PDGFR-dependent manner with effects on cell proliferation, vessel density, and macrophage infiltration. The PDGFR-selective inhibitor CP-673,451 regulated cell proliferation through mechanisms involving reduced phosphorylation of GSK-3 alpha and GSK-3 beta. Additional tissue culture studies showed a PDGFR-dependent regulation of rhabdosphere formation/cancer cell stemness, differentiation, senescence, and apoptosis. In summary, the study shows a clinically relevant distinction in PDGF signaling in human rhabdomyosarcoma and also suggests continued exploration of the influence of stromal PDGFRs on sarcoma progression. Cancer Res; 73(7); 2139-49. (C)2013 AACR.
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| 5. |
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| 6. |
- Li, Yuyang, et al.
(författare)
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Synthesis, Physicochemical Characterization, and Cytotoxicity Assessment of Rh Nanoparticles with Different Morphologies-as Potential XFCT Nanoprobes
- 2020
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Ingår i: Nanomaterials. - : MDPI AG. - 2079-4991. ; 10:11, s. 2129-2129
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Tidskriftsartikel (refereegranskat)abstract
- Morphologically controllable synthesis of Rh nanoparticles (NPs) was achieved by the use of additives during polyol synthesis. The effect of salts and surfactant additives including PVP, sodium acetate, sodiumcitrate, CTAB,CTAC,andpotassiumbromideonRhNPsmorphologywasinvestigated. When PVP was used as the only additive, trigonal NPs were obtained. Additives containing Br− ions (CTAB and KBr) resulted in NPs with a cubic morphology, while those with carboxyl groups (sodium citrate and acetate) formed spheroid NPs. The use of Cl− ions (CTAC) resulted in a mixture of polygon morphologies. Cytotoxicity of these NPs was evaluated on macrophages and ovarian cancer cell lines. Membrane integrity and cellular activity are both influenced to a similar extent, for both the cell lines, with respect to the morphology of Rh NPs. The cells exposed to trigonal Rh NPs showed the highest viability, among the NP series. Particles with a mixed polygon morphology had the highest cytotoxic impact, followed by cubic and spherical NPs. The Rh NPs were further demonstrated as contrast agents for X-ray fluorescence computed tomography (XFCT) in a small-animal imaging setting. This work provides a detailed route for the synthesis, morphology control, and characterization of Rh NPs as viable contrast agents for XFCT bio-imaging.
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| 7. |
- Ohlson, Lena
(författare)
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In vivo studies of cell cycle regulating proteins in rats during liver regeneration and during promotion of liver carcinogenesis
- 2004
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- There are more than one hundred different types of cancer in humans. However, the major platform for all types of cancer is automous and uncontrolled cell division and though most types of cancer are possible to treat and cure by surgery, chemical therapy or irradiation, more efficient and less toxic therapies are urgently needed. In the modern society we are exposed to more toxins than ever. The liver, as main detoxifier of our blood, is handling many hazardous compounds. Unfortunately, after being metabolised in the liver, many of these are able to act as promoters for one of the most lethal types of cancer, the hepatocellular carcinoma (HCC). Previous studies demonstrated that nuclear accumulation of p53 and other proteins is essential for efficient tumor suppression. Based on this, the aim of the study was to investigate whether altered localization and/or p53 protein expression is an early event in tumor development in liver that possibly contributes to the growth advantage of initiated hepatocytes. We also addressed the question of which impact 2-AAF exerts on cell cycle at early stages of tumor promotion. Preneoplastic foci were induced in rat liver by treatment with diethylnitroseamin (DEN), combined with either of the four tumor promoters, 2acetylaminofluorene, 17-alpha ethinylestradiol, choline-deficient diet or deoxycholic acid. This was combined with 2/3 partial hepatectomy as a proliferative stimulus. The immunohistochemical results showed that all four promoters decreased the focal expression of p53 and p21, two proteins known to inhibit replication upon DNA damage, in both nucleus and cytoplasm. In contrast, in surrounding tissue increased nuclear levels of p53 and p21 was observed. These data suggest that deregulation of p53 and p21 might be a common feature occurring early during promotion of HCC in vivo. We also found that treatment with 2-AAF prevented the induction of nuclear p53 in foci in response to gamma-irradiation in initiated male Wistar rats, which correlated with increased cytoplasmic expression of Mdm2 and Bcl-2 in foci. It is possible that complex formation with elevated Mdm2 together with increased Bcl-2 protein expression contributes to the sequestration and inactivation of p53 in cytoplasm. Growth signalling in regenerating liver was studied in non-initiated rats subjected to the tumor promoter 2-AAF. We found that 2-AAF exercise an almost complete mitoinhibitory effect in synchronised hepatocytes. Nuclear levels of cdk 4, cyclin D3, cyclin E, p53, p 130 and pRb were increased while the levels of PCNA, cdk 2, E2F- 1, -3 and -4 were decreased. Furthermore, both nuclear and cytoplasmic expression of cyclin A and - B proteins was lost. Finally, we found that p107 a member of the Rb-family and necessary for S-phase progression, but not pRB was increased in normal regenerating liver. In mitoinhibited liver the expression level of these two proteins was rather the opposit indicating slightly different roles for pRb and p107 during regeneration and cell cycle control, at least in this animal model.
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| 8. |
- Saladino, Giovanni, et al.
(författare)
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Carbon Quantum Dots Conjugated Rhodium Nanoparticles as Hybrid Multimodal Contrast Agents
- 2021
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Ingår i: Nanomaterials. - : MDPI AG. - 2079-4991. ; 11:9
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Tidskriftsartikel (refereegranskat)abstract
- Nanoparticle (NP)-based contrast agents enabling different imaging modalities are sought for non-invasive bio-diagnostics. A hybrid material, combining optical and X-ray fluorescence is presented as a bioimaging contrast agent. Core NPs based on metallic rhodium (Rh) have been demonstrated to be potential X-ray Fluorescence Computed Tomography (XFCT) contrast agents. Microwave-assisted hydrothermal method is used for NP synthesis, yielding large-scale NPs within a significantly short reaction time. Rh NP synthesis is performed by using a custom designed sugar ligand (LODAN), constituting a strong reducing agent in aqueous solution, which yields NPs with primary amines as surface functional groups. The amino groups on Rh NPs are used to directly conjugate excitation-independent nitrogen-doped carbon quantum dots (CQDs), which are synthesized through citrate pyrolysis in ammonia solution. CQDs provided the Rh NPs with optical fluorescence properties and improved their biocompatibility, as demonstrated in vitro by Real-Time Cell Analysis (RTCA) on a macrophage cell line (RAW 264.7). The multimodal characteristics of the hybrid NPs are confirmed with confocal microscopy, and X-ray Fluorescence (XRF) phantom experiments.
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| 9. |
- Saladino, Giovanni, et al.
(författare)
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Iterative Nanoparticle Bioengineering Enabled by X-Ray Fluorescence Imaging
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Nanoparticles (NPs) are currently developed for drug delivery and molecular imaging. However, they often get intercepted before reaching their target, leading to low targeting efficacy and signal-to-noise ratio. They tend to accumulate in organs like lungs, liver, kidneys, and spleen. The remedy is to iteratively engineerNP surface properties and administration strategies, presently a time-consuming process that includes dissection at different time points. To improve this, we propose a rapid iterative approach using whole-animal X-ray fluorescence (XRF) imaging to systematically evaluate NP distribution in vivo. We applied this method to molybdenum-based NPs and clodronate liposomes for tumor targeting with transient macrophage depletion, leading to reduced accumulations in lungs and liver and eventual tumor detection.XRF computed tomography (XFCT) provided 3D insight into NP distribution within the tumor. We validated the results using a multiscale imaging approach with dye-doped NPs and gene expression analysis for nanotoxicological profiling. XRF imaging holds potential for advancing therapeutics and diagnostics in preclinical pharmacokinetic studies.
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| 10. |
- Saladino, Giovanni Marco, et al.
(författare)
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Functional Coatings for X-ray Fluorescent Nanoparticles
- 2022
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Ingår i: Proceedings of the 6th International Conference on Theoretical and Applied Nanoscience and Nanotechnology, TANN 2022. - : Avestia Publishing.
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Konferensbidrag (refereegranskat)abstract
- In recent years, the design and synthesis of bio-compatible coatings leading to hybrid nanoparticles (NPs) as the contrast agents have gained substantial relevance. Furthermore, the addition of several functionalities for bio-imaging applications represents a key step for non-invasive bio-diagnostics. In this context, we design and utilize hybrid nanostructures for X-ray fluorescence computed tomography (XFCT). The combination of a ceramic or metallic core–based on MoO2, Rh or Ru–with a protective shell allows the generation of bio-compatible nanohybrids for dual mode bio-imaging, where the core NPs constitute the X-ray fluorescence (XRF) contrast agents [1]–[3]. Core NPs are synthesized via polyol, hydrothermal or microwave-assisted hydrothermal methods, yielding uniform shape and high dispersibility in aqueous media. Different approaches have been pursued for the fabrication of a bio-compatible shell coating. A modified sol-gel based silica coating process, doped with a commercial fluorophore (Cy5.5), was developed and shown to be applicable to both ceramic and metallic NPs [4], forming core-shell NPs with both optical and X-ray fluorescence properties. Alternatively, carbon quantum dots (CQDs) were synthesized via citrate pyrolysis using microwave-assisted hydrothermal method, exhibiting uniform size distribution (1.6±0.4 nm) and excitation-independent emission (440 nm). Conjugation of these CQDs, via cross-linking, with Rh NPs led to excitation-independent hybrid NPs, with a red-shifted emission wavelength (520 nm), attributed to the reduction of pyrrolic nitrogen on CQDs [5]. These hybrid NPs exhibit improved in vitro biocompatibility in comparison with bare XRF contrast agents. Furthermore, the optical fluorescence–provided by Cy5.5 or CQDs–allows the localization of the NPs in the intracellular environment while the XRF signal from the core NPs is utilized for XFCT, in small animals, leading to both a microscopic and macroscopic bio-imaging contrast agent.
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