Ontology highlight
ABSTRACT:
PROVIDER: PRJEB25961 | ENA |
REPOSITORIES: ENA
Similar Datasets
Project description:Immune checkpoint inhibitors are used to restore or augment antitumor immune response and show great promise in treatment of melanoma and other types of cancers. However, only a relatively small percentage of patients are fully responsive to immune checkpoint inhibition, mostly due to tumor heterogeneity and primary resistance to therapy. Both of these features are largely driven by accumulation of patient-specific mutations, pointing to the need for personalized approaches in diagnostics and immunotherapy. Proteogenomics integrates patient-specific genomic and proteomic data to study cancer development and resistance mechanisms, as well as tumor heterogeneity in individual patients. Here, we use a proteogenomic approach to characterize the mutational landscape of samples derived from four clinical melanoma patients at the genomic, proteomic and phosphoproteomic level. Integration of datasets enabled identification and quantification of an extensive number of sample-specific amino acid variants, among them many were not previously reported in melanoma. We detected a disproportional number of alternate peptides between treated and untreated (naïve) samples with a high potential to influence signal transduction. This is one of the first proteogenomic study designed to study the mutational landscape of patient-derived melanoma tissue samples in response to immunotherapy.
2022-02-16 | PXD028700 | Pride
Project description:Chronic sun-damaged (CSDhigh) melanoma represents 10-20% of cutaneous melanomas and is characterized by infrequent BRAF V600E mutations and high mutational load. However, the order of genetic events, or the extent of intra-tumor heterogeneity (ITH) in CSDhigh melanoma is still unknown. Ultra-deep targeted sequencing of 40 cancer-associated genes was performed in 73 in situ or invasive CMM, including 23 CSDhigh cases. In addition, we performed whole-exome and RNA sequencing on multiple regions of primary tumor and multiple in-transit metastases from one CSDhigh melanoma patient. We found no significant difference in mutation frequency in melanoma-related genes or in mutational load between in situ and invasive CSDhigh lesions while this difference was observed in CSDlow lesions. In addition, increased frequency of BRAF V600K, NF1 and TP53 mutations (P < 0.01, Fisher’s Exact Test) was found in CSDhigh melanomas. Sequencing of multiple specimens from one CSDhigh patient revealed strikingly limited ITH with > 95% shared mutations. Our results provide evidence that CSDhigh and CSDlow melanomas are distinct molecular entities that progress via different genetic routes.
2020-05-19 | GSE139362 | GEO
Project description:Syngeneic grafts of the D4M.3A.3 (parental) mouse melanoma cell line (derived from a Tyr::CreER;BrafCA;Ptenlox/lox mouse) in C56BL/6 mice model poorly immunogenic, low neoantigen human melanomas. The D3UV2 (UV2) cell line was derived by serial UVB irradiation and single cell cloning. The addition of UVB-induced putative neoantigens sensitizes UV2 syngeneic melanoma grafts to immune checkpoint inhibitors and triggers epitope skewing to tumor-lineage self-antigens, a phenomenon that can be successfully mimicked in parental melanomas through treatment combinations such as anti-PD-1 with ablative fractional photothermolysis and imiquimod. Our mouse models were used to characterize gene expression changes between neoantigen rich and neoantigen poor melanomas, and with immunotherapy.
2021-02-16 | GSE159344 | GEO
Project description:PD-1 immune checkpoint blockade provides significant clinical benefits for cancer patients. However, factors influencing innate sensitivity remain incompletely catalogued. We analyzed the somatic mutanomes and transcriptomes of pretreatment melanoma biopsies. Mutations in cell adhesion genes and the DNA repair gene BRCA2 were enriched in responding tumors, and a high mutational load associated with improved survival. Innately resistant tumors displayed frequent transcriptomic up-expression of genes that enriched for mesenchymal transition, cell adhesion, ECM organization, wound-healing and angiogenesis. The transcriptomes of innate resistance also enriched for signatures indicating up-regulation of these processes. Notably, MAPK-targeted therapy (MAPKi) induced similar signatures in melanoma, suggesting that a form of MAPKi resistance mediates cross-resistance to anti-PD-1 therapy. Co-enrichment of IPRIM (Innate anti-PD-1 Resistance Induced by MAPKi) signatures defined a transcriptomic subset across advanced cancers, suggesting that attenuating processes underlying these signatures may augment anti-PD1 responses. Thus, multi-factorial determinants influence anti-PD-1 patterns in melanoma.
2016-03-18 | GSE78220 | GEO
Project description:Intratumor mutational heterogeneity has been documented in primary non-small cell lung cancer. Here, we elucidate mechanisms of tumor evolution and heterogeneity in metastatic thoracic tumors (lung adenocarcinoma and thymic carcinoma) using whole-exome and transcriptome sequencing, SNP array for copy number alterations (CNA) and mass spectrometry-based quantitative proteomics of metastases obtained by rapid autopsy. APOBEC-mutagenesis, promoted by increased expression of APOBEC3 region transcripts and associated with a high-risk germline APOBEC3 variant, strongly correlated with mutational tumor heterogeneity. TP53 mutation status was associated with APOBEC hypermutator status. Interferon pathways were enriched in tumors with high APOBEC mutagenesis and IFN- induced expression of APOBEC3B in lung adenocarcinoma cells in culture suggesting a role for the immune microenvironment in the generation of mutational heterogeneity. CNA occurring late in tumor evolution correlated with downstream transcriptomic and proteomic heterogeneity, although global proteomic heterogeneity was significantly greater than transcriptomic and CNA heterogeneity. These results illustrate key mechanisms underlying multi-dimensional heterogeneity in metastatic thoracic tumors.
2019-05-07 | PXD012845 | Pride
Project description:<p>Immune checkpoint inhibitors are effective cancer treatments, but molecular determinants of clinical benefit are unknown. Ipilimumab and tremelimumab are antibodies against cytotoxic T-lymphocyte antigen 4 (CTLA-4). Anti-CTLA-4 treatment prolongs overall survival in patients with melanoma. CTLA-4 blockade activates T cells and enables them to destroy tumor cells.</p> <p>We obtained tumor tissue from patients with melanoma who were treated with ipilimumab or tremelimumab. Whole-exome sequencing was performed on tumors and matched blood samples. Somatic mutations and candidate neoantigens generated from these mutations were characterized. Neoantigen peptides were tested for the ability to activate lymphocytes from ipilimumab-treated patients.</p> <p>Malignant melanoma exomes from 64 patients treated with CTLA-4 blockade were characterized with the use of massively parallel sequencing. A discovery set consisted of 11 patients who derived a long-term clinical benefit and 14 patients who derived a minimal benefit or no benefit. Mutational load was associated with the degree of clinical benefit (P = 0.01) but alone was not sufficient to predict benefit. Using genomewide somatic neoepitope analysis and patient-specific HLA typing, we identified candidate tumor neoantigens for each patient. We elucidated a neo-antigen landscape that is specifically present in tumors with a strong response to CTLA-4 blockade. We validated this signature in a second set of 39 patients with melanoma who were treated with anti-CTLA-4 antibodies. Predicted neoantigens activated T cells from the patients treated with ipilimumab.</p>
| phs001041 | dbGaP
Project description:In this comprehensive study, the authors have developed concise models integrating clinical, genomic and transcriptomic features to predict intrinsic resistance to anti-PD1 Immune Checkpoint Blockade (ICB) treatment in individual tumors. It's important to note that their validation was performed in smaller, independent cohorts, constrained by data availability. The authors have developed two Logistic Regression based models for Ipilimumab treated and Ipilimumab naive patients with metastatic melanoma. The main predictive features for the Ipilimumab treated patients are MHC-II HLA, LDH at treatment initiation and the presence of lymph node metastases (LN met), chosen using forward selection methodology. The main predictive features for the Ipilimumab naive patients are tumor heterogeneity, tumor ploidy and tumor purity, chosen using forward selection methodology.
Please note that in these models, the output ‘1’ means progressive disease (PD) and ‘0’ means non-PD. The original GitHub repository can be accessed at https://github.com/vanallenlab/schadendorf-pd1
2023-11-17 | MODEL2310150001 | BioModels
Project description:T cell inhibitory mechanisms prevent autoimmune reactions, while cancer immunotherapy aims to remove these inhibitory signals, Chronic UV exposure attenuates autoimmunity through promotion of unknown immune-suppressive mechanisms. Here we showed that mice with subcutaneous melanoma were not responsive to anti-PD1 immunotherapy following chronic UV irradiation, given prior to tumor injection, due to the suppression of T cell killing ability in skin-draining lymph nodes. Using mass cytometry and single-cell RNA-sequencing analyses, we discovered that skin-specific, UV-induced suppression of T-cells killing activity is mediated by upregulation of Ly6ahigh T-cells subpopulation. Independently of the UVB effect, Ly6ahigh T cells were induced by chronic type-1 interferon in the tumor microenvironment. Treatment with an anti-Ly6a antibody enhanced the anti-tumoral cytotoxic activity of T cells and reprogrammed their mitochondrial metabolism via the Erk/cMyc axis. Remarkably, treatment with anti-Ly6a antibody significantly inhibited tumor growth in mice resistant to anti-PD1 therapy. Applying our findings in humans could lead to a new immunotherapy treatment for patients with resistance to existing treatments.
2024-08-04 | GSE272861 | GEO
Project description:<p>Desmoplastic melanoma (DM) is a rare subtype of melanoma characterized by dense fibrous stroma, resistance to chemotherapy and a lack of actionable driver mutations, but is highly associated with ultraviolet light DNA damage. We analysed 60 patients with advanced DM treated with programmed cell death 1 (PD-1) or PD-1 ligand (PD-L1) blocking antibody therapy. Objective tumor responses were observed in 42 of the 60 patients (70%, 95% confidence interval 57-81%), including 19 patients (32% overall) with a complete response. Whole-exome sequencing revealed a high mutational load and frequent NF-1 mutations (14 out of 17 cases). Immunohistochemistry (IHC) analysis from 19 DM and 13 non-DM revealed a higher percentage of PD-L1 positive cells in the tumor parenchyma in DM (p = 0.04), highly associated with increased CD8 density and PD-L1 expression in the tumor invasive margin. Therefore, patients with advanced DM derive significant clinical benefit from PD-1/PD-L1 immune checkpoint blockade therapy despite being a cancer defined by its dense desmoplastic fibrous stroma. The benefit is likely derived from the high mutational burden and a frequent pre-existing adaptive immune response limited by PD-L1 expression.</p>
| phs001469 | dbGaP
Project description:In this manuscript, the authors had hypothesized a multi-dimensional approach modeling of both tumor and immune-related molecular mechanisms would better predict immune checkpoint blockade (ICB) response than simpler mutation-focused biomarkers, such as tumor mutational burden (TMB). The authors showed that the predictive power increases with deeper modeling of neoantigens and immune-related resistance mechanisms of ICB. The neoantigen burden score (NBS) and composite neoantigen presentation score (NEOPS) mentioned in the transcript was fully reproduced. Internally they used XGBoost algorithm to generate the results and the same is provided as dataset file. That is, the dataset provided here demonstrates that their integrative approach outperformed single-analyte biomarkers such as those found in cohort of patients with late-stage melanoma. This model is now addresses the issues in reproducing itself which was caused by version changes and deprecation of some R packages. It uses checkpoint package, which acts as a time machine for CRAN packages thereby promoting FAIReR sharing of ML models.
2024-07-23 | MODEL2407210001 | BioModels