Dataset Information

Epigenetic analysis of the Notch superfamily in high-grade serous ovarian cancer.

ABSTRACT: Gene methylation and other epigenetic modifications of gene regulation have been implicated in the growth of ovarian cancer, but the clinical significance of such modifications in the Notch pathway in high-grade serous ovarian cancer (HGS-OvCa) is not well understood. We used The Cancer Genome Atlas (TCGA) data to study the clinical relevance of epigenetic modifications of Notch superfamily genes.We analyzed the interaction of DNA methylation and miRNAs with gene expression data for Notch superfamily members with the Spearman rank correlation test and explored potential relationships with overall survival (OS) with the log-rank test. We downloaded clinical data, level 3 gene expression data, and level 3 DNA methylation data for 480 patients with stage II-IV HGS-OvCa from the TCGA data portal. Patients were randomly divided into training and validation cohorts for survival analyses. In each set, patients were grouped into percentiles according to methylation and microRNA (miRNA) or messenger RNA (mRNA) levels. We used several algorithms to predict miRNA-mRNA interaction.There were significant inverse relationships between methylation status and mRNA expression for PPARG, CCND1, and RUNX1. For each of these genes, patients with a lower methylation level and higher expression level had significantly poorer OS than did patients with a higher methylation level and lower expression level. We also found a significant inverse relationship between miRNAs and mRNA expression for CCND1, PPARG, and RUNX1. By further analyzing the effect of miRNAs on gene expression and OS, we found that patients with higher levels of CCND1, PPARG, and RUNX1 expression and lower expression levels of their respective miRNAs (502-5p, 128, and 215/625) had significantly poorer OS.Epigenetic alterations of multiple Notch target genes and pathway interacting genes (PPARG, CCND1, and RUNX1) may relate to activation of this pathway and poor survival of patients with HGS-OvCa.

SUBMITTER: Ivan C

PROVIDER: S-EPMC3645276 | biostudies-literature | 2013 Mar

REPOSITORIES: biostudies-literature

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Epigenetic analysis of the Notch superfamily in high-grade serous ovarian cancer.

Ivan Cristina C Hu Wei W Bottsford-Miller Justin J Zand Behrouz B Dalton Heather J HJ Liu Tao T Huang Jie J Nick Alpa M AM Lopez-Berestein Gabriel G Coleman Robert L RL Baggerly Keith A KA Sood Anil K AK

Gynecologic oncology 20121128 3

<h4>Objectives</h4>Gene methylation and other epigenetic modifications of gene regulation have been implicated in the growth of ovarian cancer, but the clinical significance of such modifications in the Notch pathway in high-grade serous ovarian cancer (HGS-OvCa) is not well understood. We used The Cancer Genome Atlas (TCGA) data to study the clinical relevance of epigenetic modifications of Notch superfamily genes.<h4>Methods</h4>We analyzed the interaction of DNA methylation and miRNAs with ge ...[more]

PMID: 23200915

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Project description:Ovarian cancer (OC) cells frequently metastasize to the omentum, and adipocytes play a significant role in ovarian tumor progression. Therapeutic interventions targeting aberrant DNA methylation in ovarian tumors have shown promise in the clinic, but the effects of epigenetic therapy on the tumor microenvironment are understudied. Here, we examined the effect of adipocytes on OC cell behavior in culture and impact of targeting DNA methylation in adipocytes on OC metastasis. The presence of adipocytes increased OC cell migration and invasion, and proximal and direct coculture of adipocytes increased OC proliferation alone or after treatment with carboplatin. Treatment of adipocytes with hypomethylating agent guadecitabine decreased migration and invasion of OC cells toward adipocytes. Subcellular protein fractionation of adipocytes treated with guadecitabine revealed decreased DNA methyltransferase 1 (DNMT1) levels even in the presence of DNA synthesis inhibitor, aphidicolin. Methyl-Capture- and RNA-sequencing analysis of guadecitabine-treated adipocytes revealed derepression of tumor-suppressor genes and epithelial-mesenchymal transition inhibitors. SUSD2, a secreted tumor suppressor downregulated by promoter CpG island methylation in adipocytes, was upregulated after guadecitabine treatment, and recombinant SUSD2 decreased OC cell migration and invasion. Integrated analysis of the methylomic and transcriptomic data identified pathways associated with inhibition of matrix metalloproteases and fatty acid α-oxidation, suggesting a possible mechanism of how epigenetic therapy of adipocytes decreases metastasis. In conclusion, the effect of DNMT inhibitor on fully differentiated adipocytes suggests that hypomethylating agents may affect the tumor microenvironment to decrease cancer cell metastasis.Implications: Epigenetic targeting of tumor microenvironment can affect metastatic behavior of ovarian cancer cells. Mol Cancer Res; 16(8); 1226-40. ©2018 AACR.

Project description:BackgroundDeregulation of integrins signaling had been documented to participate in multiple fundamental biological processes, and the aberrant expression of integrin family members were linked to the prognosis of various cancers. However, the role of integrins in predicting progression and prognosis of ovarian cancer patients are still largely elusive. This study is aimed to explore the prognostic values of ITGA and ITGB superfamily members in high grade serous ovarian cancers (HGSOC).MethodsGSE26712 dataset was used to determine the differential expression of ITGA and ITGB superfamily member between HGSOC and normal counterparts. The Cancer Genome Altas (TGGA) and GSE9891 datasets were used to determine the prognostic values of ITGA and ITGB superfamily members in HGSOC, followed by the development of nomograms predictive of recurrence free survival (RFS) and overall survival (OS).ResultsITGA6 and ITGB5 expression were significantly downregulated in HGSOC compared with that in normal counterparts. In contrast, ITGA2, ITGA5, ITGA7, ITGA8, ITGA9, ITGA10, ITGB3, ITGB4, ITGB6, and ITGB8 were all significantly upregulated in HGSOC compared with that in normal counterparts. Both univariable and multivariable analysis indicated that ITGB1 was associated with extended RFS. The ITGB1-related nomogram indicated that ITGB1 had the largest contribution to RFS, followed by FIGO stage and debulking status. The C-index for predicting RFS was 0.55 (95% CI 0.50-0.59) in TCGA dataset (training dataset) and 0.65 (95% CI 0.59-0.72) in GSE9891 dataset (validation dataset), respectively. Regarding OS, ITGB8 was associated with reduced survival suggested by both univariable and multivariable analysis. ITGA7 appeared to be associated with improved survival though without reaching statistical significance. The ITGA7/ITGB8-based nomogram showed that age at initial diagnosis had the largest contribution to OS, followed by ITGB8 and ITGA7 expression. The C-index for predicting OS was 0.65 (95% CI 0.60-0.69) in TCGA dataset (training dataset) and 0.59 (95% CI 0.51-0.66) in GSE9891 dataset (validation dataset), respectively.ConclusionIn conclusion, ITGB1, ITGA7 and ITGB8 added prognostic value to the traditional clinical risk factors used to assess the clinical outcomes of HGSOC.

Project description:PurposeOvarian cancer is the leading cause of gynecologic cancer-related death worldwide. Early diagnosis of ovarian cancer can significantly improve patient prognosis. Hence, there is an urgent need to identify key diagnostic and prognostic biomarkers specific for ovarian cancer. Because high-grade serous ovarian cancer (HGSOC) is the most common type of ovarian cancer and accounts for the majority of deaths, we identified potential biomarkers for the early diagnosis and prognosis of HGSOC.MethodsSix datasets (GSE14001, GSE18520, GSE26712, GSE27651, GSE40595, and GSE54388) were downloaded from the Gene Expression Omnibus database for analysis. Differentially expressed genes (DEGs) between HGSOC and normal ovarian surface epithelium samples were screened via integrated analysis. Hub genes were identified by analyzing protein-protein interaction (PPI) network data. The online Kaplan-Meier plotter was utilized to evaluate the prognostic roles of these hub genes. The expression of these hub genes was confirmed with Oncomine datasets and validated by quantitative real-time PCR and Western blotting.ResultsA total of 103 DEGs in patients with HGSOC-28 upregulated genes and 75 downregulated genes-were successfully screened. Enrichment analyses revealed that the upregulated genes were enriched in cell division and cell proliferation and that the downregulated genes mainly participated in the Wnt signaling pathway and various metabolic processes. Ten hub genes were associated with HGSOC pathogenesis. Seven overexpressed hub genes were partitioned into module 1 of the PPI network, which was enriched in the cell cycle and DNA replication pathways. Survival analysis revealed that MELK, CEP55 and KDR expression levels were significantly correlated with the overall survival of HGSOC patients (P < 0.05). The RNA and protein expression levels of these hub genes were validated experimentally.ConclusionBased on an integrated analysis, we propose the further investigation of MELK, CEP55 and KDR as promising diagnostic and prognostic biomarkers of HGSOC.

Dataset Information

Epigenetic analysis of the Notch superfamily in high-grade serous ovarian cancer.

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Epigenetic analysis of the Notch superfamily in high-grade serous ovarian cancer.

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