Abstract 158: Expression of miR-205 is significantly associated with prognosis of endometrial cancer

Abstract

Background: microRNAs (miRNAs) have emerged as key regulators of gene expression, and their altered expression has been associated with tumorigenesis and tumor progression. As a result, miRNAs represent important diagnostic biomarkers for the advancement of cancer and potential therapeutic approaches. They may be up-regulated or down-regulated in various tumor types, thus act as oncogenes or tumor suppressors. Although accumulating evidence suggests the role of aberrant miRNA expression in endometrial carcinogenesis, there is still limited data available about the endrometrial miRNAs. Endometrial cancer is characterized by frequently infiltrating tumors, and one of the most important molecular alterations in this process is through epithelial-mesencymal transition (EMT). Several studies implicated the role of miRNAs targeting the critical players during EMT. The goal of this study is to investigate the clinical utility of selected key miRNAs in archival FFPE tissue samples of patients with endometrial cancer. In this study, the expression of miR-26a, miR-205, miR-200c, miR-192, miR-215, let-7g, miR-21, miR-181b were quantified from 20 stage I, 2 stage II, 5 stage III, 8 stage IV endometrial cancer patients (endometrioid-type endometrial cancer (EEC), endometrial serous carcinoma(ESC), clear cell carcinoma(CCC) undifferentiated carcinoma (UDC), malignant mullerian mixed tumor (MMMT)) with up to 15 years clinical follow up information. Methods: Using archival FFPE tissues, areas of tumor and normal tissues were identified according to the corresponding hematoxylin and eosin stained sections, and cores of 1.5 mm in diameter were extracted. Total RNAs were isolated from 35 paired endometrial tumor and adjacent normal tissue specimens by using Trizol based approach. The expression levels of miRNAs were quantified by using real-time qRT-PCR analysis. Results: The expression of miR-205 (p=0.0002) and miR-200c (p<0.0001) were significantly elevated in endometrial cancer tissue specimens when compared to adjacent normal tissues. Kaplan-Meier survival analysis indicated that low levels of miR-205 expression (hazard ratio, 0.309; log rank test, p=0.018) is closely associated with better patient's overall survival. Conclusions: miR-205 holds a great potential as a prognostic biomarker in endometrial cancer. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 158. doi:10.1158/1538-7445.AM2011-158