| 1. |
- Eissler, Nina, et al.
(författare)
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Affibody PET Imaging of HER2-Expressing Cancers as a Key to Guide HER2-Targeted Therapy
- 2024
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Ingår i: Biomedicines. - : MDPI. - 2227-9059. ; 12:5
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Forskningsöversikt (refereegranskat)abstract
- Human epidermal growth factor receptor 2 (HER2) is a major prognostic and predictive marker overexpressed in 15-20% of breast cancers. The diagnostic reference standard for selecting patients for HER2-targeted therapy is based on the analysis of tumor biopsies. Previously patients were defined as HER2-positive or -negative; however, with the approval of novel treatment options, specifically the antibody-drug conjugate trastuzumab deruxtecan, many breast cancer patients with tumors expressing low levels of HER2 have become eligible for HER2-targeted therapy. Such patients will need to be reliably identified by suitable diagnostic methods. Biopsy-based diagnostics are invasive, and repeat biopsies are not always feasible. They cannot visualize the heterogeneity of HER2 expression, leading to a substantial number of misdiagnosed patients. An alternative and highly accurate diagnostic method is molecular imaging with radiotracers. In the case of HER2, various studies demonstrate the clinical utility and feasibility of such approaches. Radiotracers based on Affibody((R)) molecules, small, engineered affinity proteins with a size of similar to 6.5 kDa, are clinically validated molecules with favorable characteristics for imaging. In this article, we summarize the HER2-targeted therapeutic landscape, describe our experience with imaging diagnostics for HER2, and review the currently available clinical data on HER2-Affibody-based molecular imaging as a novel diagnostic tool in breast cancer and beyond.
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| 2. |
- Eissler, Nina, et al.
(författare)
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Regulation of myeloid cells by activated T cells determines the efficacy of PD-1 blockade
- 2016
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Ingår i: Oncoimmunology. - : Taylor & Francis. - 2162-4011 .- 2162-402X. ; 5:12
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Tidskriftsartikel (refereegranskat)abstract
- Removal of immuno-suppression has been reported to enhance antitumor immunity primed by checkpoint inhibitors. Although PD-1 blockade failed to control tumor growth in a transgenic murine neuroblastoma model, concurrent inhibition of colony stimulating factor 1 receptor (CSF-1R) by BLZ945 reprogrammed suppressive myeloid cells and significantly enhanced therapeutic effects. Microarray analysis of tumor tissues identified a significant increase of T-cell infiltration guided by myeloid cell-derived chemokines CXCL9, 10, and 11. Blocking the responsible chemokine receptor CXCR3 hampered T-cell infiltration and reduced antitumor efficacy of the combination therapy. Multivariate analysis of 59 immune-cell parameters in tumors and spleens detected the correlation between PD-L1-expressing myeloid cells and tumor burden. In vitro, anti-PD-1 antibody Nivolumab in combination with BLZ945 increased the activation of primary human T and NK cells. Importantly, we revealed a previously uncharacterized pathway, in which T cells secreted M-CSF upon PD-1 blockade, leading to enhanced suppressive capacity of monocytes by upregulation of PD-L1 and purinergic enzymes. In multiple datasets of neuroblastoma patients, gene expression of CD73 correlated strongly with myeloid cell markers CD163 and CSF-1R in neuroblastoma tumors, and associated with worse survival in high-risk patients. Altogether, our data reveal the dual role of activated T cells on myeloid cell functions and provide a rationale for the combination therapy of anti-PD-1 antibody with CSF-1R inhibitor.
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| 3. |
- Milosevic, Jelena, et al.
(författare)
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PPM1D is a neuroblastoma oncogene and therapeutic target in childhood neural tumors
- 2020
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Majority of cancers harbor alterations of the tumor suppressor TP53. However, childhood cancers, including unfavorable neuroblastoma, often lack TP53 mutations despite frequent loss of p53 function, suggesting alternative p53 inactivating mechanisms.Here we show that p53-regulating PPM1D at chromosome 17q22.3 is linked to aggressive tumors and poor prognosis in neuroblastoma. We identified that WIP1-phosphatase encoded by PPM1D, is activated by frequent segmental 17q-gain further accumulated during clonal evolution, gene-amplifications, gene-fusions or gain-of-function somatic and germline mutations. Pharmacological and genetic manipulation established WIP1 as a druggable target in neuroblastoma. Genome-scale CRISPR-Cas9 screening demonstrated PPM1D genetic dependency in TP53 wild-type neuroblastoma cell lines, and shRNA PPM1D knockdown significantly delayed in vivo tumor formation. Establishing a transgenic mouse model overexpressing PPM1D showed that these mice develop cancers phenotypically and genetically similar to tumors arising in mice with dysfunctional p53 when subjected to low-dose irradiation. Tumors include T-cell lymphomas harboring Notch1-mutations, Pten-deletions and p53-accumulation, adenocarcinomas and PHOX2B-expressing neuroblastomas establishing PPM1D as a bona fide oncogene in wtTP53 cancer and childhood neuroblastoma. Pharmacological inhibition of WIP1 suppressed the growth of neural tumors in nude mice proposing WIP1 as a therapeutic target in neural childhood tumors.
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| 4. |
- Milosevic, Jelena, et al.
(författare)
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PPM1D Is a Therapeutic Target in Childhood Neural Tumors.
- 2021
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Ingår i: Cancers. - : MDPI AG. - 2072-6694. ; 13:23
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Tidskriftsartikel (refereegranskat)abstract
- Childhood medulloblastoma and high-risk neuroblastoma frequently present with segmental gain of chromosome 17q corresponding to aggressive tumors and poor patient prognosis. Located within the 17q-gained chromosomal segments is PPM1D at chromosome 17q23.2. PPM1D encodes a serine/threonine phosphatase, WIP1, that is a negative regulator of p53 activity as well as key proteins involved in cell cycle control, DNA repair and apoptosis. Here, we show that the level of PPM1D expression correlates with chromosome 17q gain in medulloblastoma and neuroblastoma cells, and both medulloblastoma and neuroblastoma cells are highly dependent on PPM1D expression for survival. Comparison of different inhibitors of WIP1 showed that SL-176 was the most potent compound inhibiting medulloblastoma and neuroblastoma growth and had similar or more potent effects on cell survival than the MDM2 inhibitor Nutlin-3 or the p53 activator RITA. SL-176 monotherapy significantly suppressed the growth of established medulloblastoma and neuroblastoma xenografts in nude mice. These results suggest that the development of clinically applicable compounds inhibiting the activity of WIP1 is of importance since PPM1D activating mutations, genetic gain or amplifications and/or overexpression of WIP1 are frequently detected in several different cancers.
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