Multi-omic analysis of homologous recombination deficient, end-stage ovarian cancer [Expression]
Ontology highlight
ABSTRACT:
ORGANISM(S): Homo sapiens
PROVIDER: GSE217672 | GEO | 2022/11/12
REPOSITORIES: GEO
Similar Datasets
Project description:High grade serous ovarian cancer (HGSC) is frequently characterized by homologous recombination (HR) DNA repair deficiency, and while most such tumors are sensitive to initial treatment, acquired resistance is common. We undertook a multi-omics approach to interrogate the molecular diversity in end-stage disease, using multiple autopsy samples collected from 15 women with HR-deficient HGSC. Patients had polyclonal disease, and several resistance mechanisms were identified within most patients, including reversion mutations and HR restoration by other means. We also observed frequent whole genome duplication, and global changes in immune composition with evidence of immune escape. This analysis highlights diverse evolutionary changes within HGSC that conspire to evade therapy and ultimately overwhelm individual patients. Methylation profiling was done on 29 end stage high grade serous ovarian cancer samples. 38 primary tumours, 6 autopsy tumours and 7 fallopian tube normals from GSE65820 were also used as part of the cohort.
2022-11-12 | GSE217673 | GEO
Project description:High grade serous cancer (HGSC) is frequently characterizsed by homologous recombination (HR) DNA repair deficiency, and while most such tumours are sensitive to initial treatment, acquired resistance is common. We undertook a multi-omics approach to interrogating mechanisms of resistance, using multiple autopsy samples collected from 15 women with HR-deficient HGSC. We observed frequent reversion mutations, resistance mechanisms restoring HR by other means, a high frequency of whole-genome duplication (WGD) suggestive of an evolutionary advantage, and global changes in immune composition with evidence of immune escape. Collectively these findings have implications for therapeutic intervention for HR-deficient HGSC.
2023-02-27 | PXD030034 | Pride
Project description:High grade serous ovarian cancer (HGSC) is frequently characterized by homologous recombination (HR) DNA repair deficiency, and while most such tumors are sensitive to initial treatment, acquired resistance is common. We undertook a multi-omics approach to interrogating mechanisms of resistance, using multiple autopsy samples collected from 15 women with HR-deficient HGSC.
| EGAS00001006789 | EGA
Project description:INO80 is an evolutionary conserved nucleosome remodelling complex that acts in transcription, replication and genome stability. It is required for resistance against genotoxic agents and involved in the repair of DNA double-strand breaks (DSB) by homologous recombination (HR). However, causes underlying the HR defect of INO80-C mutant cells have been controversially discussed. We here unite previous findings using a high-resolution system to study HR in the yeast Saccharomyces cerevisiae. We find that INO80-C has at least two distinct functions during HR, which promote DNA end resection and presynaptic filament formation, respectively. Importantly, specifically the second function is linked to the histone variant H2A.Z. In the absence of H2A.Z, presynaptic filament formation and HR are restored in INO80-C-deficient mutants, suggesting that presynaptic filament formation is the crucial INO80-C function during HR.
2017-05-14 | GSE95801 | GEO
Project description:Refractory high-grade serous carcinoma (HGSC) is one of the most severe clinical problems in gynecology, but we have barely grasped the underlying mechanism of aggressiveness and chemo-resistance. We performed gene set variation analysis and comprehensive log-rank tests on TCGA advanced serous ovarian cancer datasets. As a result, regulation of small GTPase signaling prominently correlated with poor prognosis uniquely in BRCA1/2-unmutated HGSC patients, and eventually, pathway clustering analysis discovered aberrant RAS/PI3K crosstalk as peculiar poor prognostic signature of BRCA1/2-unmutated HGSC patients. To elucidate the mechanism of poor progression triggered by RAS/PI3K, we utilized our syngeneic HGSC organoid models newly established from murine fallopian tube epithelium by making Myc overexpressing, and knocking out Trp53 and Rb1. After that, we knocked out Nf1 and Pten to induce aberrant RAS/PI3K crosstalk in the primitive HGSC model. In-vivo evaluation and growth comparison indicated that aberrant RAS/PI3K crosstalk transformed Brca1/2-unmutated HGSC modeling cells into aggressive phenotypes. Chemo-sensitivity assay also showed that the genetic manipulation made Brca1/2-unmutated HGSC modeling cells more tolerant to anti-tumor agents. To investigate biological processes that induce the aggressive and chemo-resistant phenotype, we performed gene set enrichment analysis among our HGSC models. The result showed that aberrant RAS/PI3K crosstalk induces cell cycle acceleration and downregulation of apoptosis in the HGSC cells, which backed up aggressive phenotype and chemo-resistance in our HGSC models. In conclusion, aberrant RAS/PI3K crosstalk transforms Brca1/2-unmutated HGSC modeling cells more aggressive and chemo-resistant, which was well recapitulated by our HGSC modeling organoids. The integration of our computational approach and experimental models will lead us to detect peculiar therapeutic targets against refractory HGSC.
2024-05-07 | GSE255127 | GEO
Project description:The response to Poly (ADP-ribose) polymerase inhibitors (PARPi) is dictated by homologous recombination (HR) DNA repair mechanisms and the abundance of lesions that trap PARP enzymes on chromatin. It remains unclear, however, if the established role of PARP in promoting chromatin accessibility impacts viability in these settings. Using a CRISPR based screen, we identify the PAR-binding Snf2-like ATPase, ALC1 as a key determinant of PARPi toxicity in HR-deficient cells. ALC1 loss reduced viability of BRCA mutant cells and enhanced their sensitivity to PARPi by up to 250-fold, while overcoming several known resistance mechanisms. ALC1 loss was not epistatic to other repair pathways that execute the PARPi response. Instead, ALC1 deficiency reduced chromatin accessibility concomitant with a decrease in the association of repair factors. This resulted in an accumulation of replication associated DNA damage and a reliance on HR. These findings establish PAR-dependent chromatin remodeling as a mechanistically distinct aspect of PARPi responses, implicating ALC1 inhibition as a new approach to overcome therapeutic resistance in HR-deficient cancers.
2020-12-02 | GSE149104 | GEO
Project description:The response to Poly (ADP-ribose) polymerase inhibitors (PARPi) is dictated by homologous recombination (HR) DNA repair mechanisms and the abundance of lesions that trap PARP enzymes on chromatin. It remains unclear, however, if the established role of PARP in promoting chromatin accessibility impacts viability in these settings. Using a CRISPR based screen, we identify the PAR-binding Snf2-like ATPase, ALC1 as a key determinant of PARPi toxicity in HR-deficient cells. ALC1 loss reduced viability of BRCA mutant cells and enhanced their sensitivity to PARPi by up to 250-fold, while overcoming several known resistance mechanisms. ALC1 loss was not epistatic to other repair pathways that execute the PARPi response. Instead, ALC1 deficiency reduced chromatin accessibility concomitant with a decrease in the association of repair factors. This resulted in an accumulation of replication associated DNA damage and a reliance on HR. These findings establish PAR-dependent chromatin remodeling as a mechanistically distinct aspect of PARPi responses, implicating ALC1 inhibition as a new approach to overcome therapeutic resistance in HR-deficient cancers.
2020-12-02 | GSE150955 | GEO
Project description:Patients with high-grade serous ovarian cancer (HGSC) have experienced little improvement in overall survival, and standard treatment has not advanced beyond platinum-based combination chemotherapy, during the past 30 years. To understand the drivers of clinical phenotypes better, here we use whole-genome sequencing of tumour and germline DNA samples from 92 patients with primary refractory, resistant, sensitive and matched acquired resistant disease. We show that gene breakage commonly inactivates the tumour suppressors RB1, NF1, RAD51B and PTEN in HGSC, and contributes to acquired chemotherapy resistance. CCNE1 amplification was common in primary resistant and refractory disease. We observed several molecular events associated with acquired resistance, including multiple independent reversions of germline BRCA1 or BRCA2 mutations in individual patients, loss of BRCA1 promoter methylation, an alteration in molecular subtype, and recurrent promoter fusion associated with overexpression of the drug efflux pump MDR1. Total RNA was hybridised to NanoString miRNA Human v2.1 probes, immobilized to NanoString cartridge and analysed on the NanoString Digital Analyzer. NanoString nSolver Analysis Software was utilised to check QC metrics and extract raw miRNA counts. Expression was normalised for input using the housekeeping genes. Contributor: The Australian Ovarian Cancer Study Group
2015-05-19 | E-GEOD-65819 | biostudies-arrayexpress
Project description:Gene expression studies are used to help identify disease-associated genes, by comparing the levels of expressed transcripts between cases and controls, and to identify functional genetic variants known as expression quantitative loci (eQTLs). While many of these studies are performed in blood or lymphoblastoid cell lines due to tissue accessibility, the relevance of expression differences in tissues that are not the primary site of disease is unclear. Further, many eQTLs are tissue specific. Thus, there is a clear and compelling need to conduct gene expression studies in tissues that are specifically relevant to the disease of interest. One major technical concern about using autopsy-derived tissue is how representative it is of physiologic conditions, given the effect of postmortem interval on tissue degradation. In this study, we monitored the gene expression of 13 tissue samples harvested from a rapid autopsy heart (non-failed heart) and 7 from a cardiac explant (failed heart) through 24 hours of autolysis. The 24 hour autopsy simulation design reflects a typical autopsy scenario where a body may begin cooling to ambient temperature for ~12 hours, before transportation and storage in a refrigerated room in a morgue. In addition, we also simulated a scenario wherein the body was left at room temperature for up to 24 hours before being found. RNA from the 20 samples and triplicate from the HeLa cell line were run on the Affymetrix Exon arrays according to the manufacturer's protocol. The expression profiles of 7 cardiac tissue samples from the cardiac transplant operation (explant/failed heart) and 13 from a rapid-autopsy program (autopsy/non-failed heart) were harvested under the cold- and warm-24 hour autolysis conditions. The 7 explant samples include - 2 biological replicates at 0 hr, 1 at 6 hrs, 1 at 12 hrs, 2 biological replicates at 18 hr cold-autolysis condition and 1 at 18 hr warm-autolysis condition. The 13 autopsy samples include - 3 biological replicates at 0 hr (2 from the left and 1 from the right ventricle), 1 at 6 hrs, 2 biological replicates at 12 hrs (1 from the left and 1 from the right ventricle), 3 biological replicates at 18 hr cold-autolysis condition (2 from the left and 1 from the right ventricle), 2 biological replicates at 18 hr warm-autolysis condition ( 1 from the left and 1 from the right ventricle), 1 at 24 hr cold-autolysis condition and 1 at 24 hr warm-autolysis condition. Gene expression profiles of triplicate liver and heart exon array data obtained from Affymetrix were also used as reference .
2011-09-30 | E-GEOD-32519 | biostudies-arrayexpress
Project description:Patients with high-grade serous ovarian cancer (HGSC) have experienced little improvement in overall survival, and standard treatment has not advanced beyond platinum-based combination chemotherapy, during the past 30 years. To understand the drivers of clinical phenotypes better, here we use whole-genome sequencing of tumour and germline DNA samples from 92 patients with primary refractory, resistant, sensitive and matched acquired resistant disease. We show that gene breakage commonly inactivates the tumour suppressors RB1, NF1, RAD51B and PTEN in HGSC, and contributes to acquired chemotherapy resistance. CCNE1 amplification was common in primary resistant and refractory disease. We observed several molecular events associated with acquired resistance, including multiple independent reversions of germline BRCA1 or BRCA2 mutations in individual patients, loss of BRCA1 promoter methylation, an alteration in molecular subtype, and recurrent promoter fusion associated with overexpression of the drug efflux pump MDR1.
2015-05-19 | GSE61568 | GEO