Dataset: Gene expression profiles of primary cultured ovarian cells in the presence and absence of a DNA methyltransferase inhibitor

Epithelial ovarian cancer is the leading cause of death among gynecologic malignancies. Diagnosis usually occurs after metastatic spread, largely reflecting vague symptoms of early disease combined with lack of an effective screening strategy. Epigenetic mechanisms of gene regulation, including DNA methylation, are fundamental to normal cellular function and also play a major role in carcinogenesis. To elucidate the biological and clinical relevance of DNA methylation in ovarian cancer, we conducted expression microarray analysis of 43 cell lines and 17 primary culture specimens grown in the presence or absence of DNA methyltransferase (DNMT) inhibitors. Two parameters, induction of expression and standard deviation among untreated samples, identified 378 candidate methylated genes, many relevant to TGF-beta signaling. We analyzed 43 of these genes and they all exhibited methylation. Treatment with DNMT inhibitors increased TGF-beta pathway activity. Hierarchical clustering of ovarian cancers using the 378 genes reproducibly generated a distinct gene cluster strongly correlated with TGF-beta pathway activity that discriminates patients based on age. These data suggest that accumulation of age-related epigenetic modifications leads to suppression of TGF-beta signaling and contributes to ovarian carcinogenesis. Seventeen primary cultures of ovarian cells (two pooled normal ovarian surface epithelium, two serous borderline tumors, one endometrioid and twelve serous epithelial ovarian cancers) were mock treated or treated with 5 µM 5-AzaC for 72 hours, followed by gene expression microarray analysis to enable identification of genes differentially expressed as a result of inhibition of DNA methyltransferase activity.

Species:

human

Samples:

34

Source:

E-GEOD-25427

Updated:

Dec.12, 2014

Registered:

Sep.15, 2014