ABSTRACT: Despite advances in surgery and radiotherapy of uveal melanoma (UM), many patients develop distant metastases that poorly respond to therapy. Improved therapies for the metastatic disease are therefore urgently needed. Expression of the epidermal growth factor receptor (EGFR), a target of kinase inhibitors and humanized antibodies in use for several cancers, had been reported. 48 human UMs were analyzed by expression profiling. Evidence for signaling in tumors was obtained through the application of a UM-specific EGF signature. The EGFR specific kinase inhibitor, Gefitinib, and the humanized monoclonal antibody, Cetuximab, were tested for their effect on EGFR signaling. Natural killer cell mediated antibody-dependent cellular cytotoxicity (ADCC) and TNF-alpha release was analyzed for Cetuximab. EGFR appears suited as a novel molecular drug target for therapy of uveal melanoma.
Project description:Despite advances in surgery and radiotherapy of uveal melanoma (UM), many patients develop distant metastases that poorly respond to therapy. Improved therapies for the metastatic disease are therefore urgently needed. Expression of the epidermal growth factor receptor (EGFR), a target of kinase inhibitors and humanized antibodies in use for several cancers, had been reported. 48 human UMs were analyzed by expression profiling. Evidence for signaling in tumors was obtained through the application of a UM-specific EGF signature. The EGFR specific kinase inhibitor, Gefitinib, and the humanized monoclonal antibody, Cetuximab, were tested for their effect on EGFR signaling. Natural killer cell mediated antibody-dependent cellular cytotoxicity (ADCC) and TNF-alpha release was analyzed for Cetuximab. EGFR appears suited as a novel molecular drug target for therapy of uveal melanoma. Gene expression profiles of 19 unique samples from uveal melanoma patients were measured.
Project description:We used microarray to compare global gene expression profiles between 5 GNAQ/11 mutant uveal melanoma cell lines (GNAQ mutant: 92-1, omm1.3, mel270; GNA11 mutant: omm-gn11 and upmd-1) and 5 GNAQ/11 wild type melanoma cell lines(sk-mel-2, mm415, mm485, sk-mel-5 and mum2c). Uveal melanoma is the most common intraocular tumor that mainly metastasizes to the liver in about 50% patients. Over 80% of UMs harbor GNAQ or GNA11 activating mutation. Currently there is no effective treatment available for UM patients. Results provide insights into downstream signaling of oncogenic GNAQ/11 and identification of therapeutic targets in UM.
Project description:Antibody dependent cell-mediated cytotoxicity (ADCC) provides a model for uncovering immune resistance mechanisms. We continuously exposed epidermal growth factor receptor (EGFR)+ A431 cells to KIR-deficient NK92-CD16V effector cells and the anti-EGFR mAb cetuximab. Persistent ADCC exposure yielded ADCC-resistant cells (ADCCR1) that, compared with control ADCC-sensitive cells (ADCCS1), exhibited reduced EGFR expression, overexpression of histone- and interferon-related genes and failure to activate NK cells, without evidence of epithelial: mesenchymal transition. These properties gradually reversed following withdrawal of ADCC selection pressure. A second A431-derived ADCC-resistant cell line maintained EGFR expression. Remarkably, ADCCR1 cells possessed lower expression of multiple cell surface molecules that contribute to cell: cell interactions and immune synapse formation. Classic immune checkpoints did not modulate ADCC in this unique model system of immune resistance. Just as giant tortoises (Testudinidae) can hide in their shells to avoid predation, this novel immune evasion mechanism, termed testudinidosis, can protect cells against immune attack.
Project description:Uveal melanoma (UM) arises from malignant transformation of melanocytes from the uveal tract. This rare tumor has a poor outcome with frequent liver metastases and primary resistance to treatment1. The only strong predisposing condition for UM is the BAP1 tumor predisposition syndrome due to germline BAP1 deleterious mutations. UMs are generally characterized by a very low tumor mutation burden (TMB). However, some UMs display a high level of CpG to TpG mutations associated with MBD4 inactivation. Here, we explored the incidence of germline MBD4 variants in a consecutive series of 1, 099 primary UMs, and identified 8 deleterious MBD4 mutations, an aprox 10-fold increased incidence compared with the general population. These mutations were associated with a high TMB in tested UMs. We thus demonstrated that MBD4 is the second major predisposing gene for UM.
Project description:Genome wide DNA methylation profiling of primary uveal melanoma cells, normal uveal melanocytes, neural crest stem cells, embryonic stem cells and uveal melanoma cell lines. The Illumina Infinium 27k Human DNA methylation Beadchip Rev B was used to obtain DNA methylation profiles across approximately 27,000 CpGs in the samples. Samples included 58 primary UM, 3 NUM and NCSC controls and 2 cell lines.
Project description:Background: Poly (ADP-ribose) polymerase inhibitors (PARPi) prevent single-stranded DNA repair. Olaparib is a PARPi approved for the treatment of BRCA mutant ovarian and breast carcinoma. Emerging clinical data suggest a benefit of combining olaparib with immunotherapy in prostate cancer patients both with and without somatic BRCA mutations. Methods: We examined if olaparib, when combined with IgG1 antibody-dependent cellular cytotoxicity (ADCC)-mediating monoclonal antibodies (mAbs) cetuximab (anti-EGFR), or avelumab (anti-PD-L1), would increase tumor cell sensitivity to killing by natural killer (NK) cells independently of BRCA status or mAb target upregulation. BRCA mutant and BRCA wildtype (WT) prostate carcinoma cell lines were pretreated with olaparib and then exposed to NK cells in the presence or absence of cetuximab or avelumab. Results: NK-mediated killing was significantly increased in both cell lines and was further increased using the ADCC-mediating mAbs. Pre-exposure of NK cells to recombinant IL-15/IL-15RA further increased the lysis of olaparib treated tumor cells. In addition, olaparib treated tumor cells were killed to a significantly greater degree by engineered high-affinity NK cells (haNK). We show here for the first time that (a) olaparib significantly increased tumor cell sensitivity to NK killing and ADCC in both BRCA WT and BRCA mutant prostate carcinoma cells, independent of PD-L1 or EGFR modulation; (b) mechanistically, treatment with olaparib upregulated death receptor TRAIL-R2, and (c) olaparib significantly enhanced NK killing of additional tumor types, including breast, non-small cell lung carcinoma, and chordoma. Conclusions: These studies support the combined use of NK- and ADCC-mediating agents with correctly timed PARP inhibition.
Project description:The function and mechanism of lncRNA in human uveal melanoma (UM) is not clearly studied. We used microarrays to identify the downstream target genes of CANT1 lncRNA in UM cells to explain the mechanism of lncRNA in UM tumorigenesis
Project description:The role of lncRNA in uveal melanoma (UM) is not well studied. We used microarrays to identify the downstream targets of MAT1 lncRNA to invesitgate the mechanism of lncRNA in UM oncogenesis
Project description:Purpose: In this study, we show that mutations of the splicing factor SF3B1 in uveal melanoma (UM) generate immunogenic neo-antigens.
Project description:Purpose: In this study, we show that mutations of the splicing factor SF3B1 in uveal melanoma (UM) generate immunogenic neo-antigens.