Abstract C154: microRNA and targets in the poor prognosis of ovarian cancer patients.

Abstract

Abstract Epithelial ovarian cancer (EOC) is the most important cause of gynecologic malignancy-related mortality in women. Ovarian clear cell carcinoma (CC) has a poor survival rates and ovarian papillary serous carcinoma (PSC) has a high incidence in the EOC. To get the insight of possible regulator and pathway that may involved in the EOC prognosis and progress, patient samples of CC, PSC and normal ovarian or oviduct tissues were employed in the study. Total 48 human tumor samples and 6 normal ovarian and oviduct tissues were obtained from the patients who were surgically treated for ovarian cancer or other disease at the Obstetrics and Gynecology Hospital, Dalian China. The tissue was further fixed by formalin and embedded by paraffin as routine. Total RNA that enriched miRNAs was extracted from the FFPE tissue by using the Ambion mirVana microRNA isolation kit (Ambion, Austin TX). The quality of total RNA was assessed using the Agilent Bioanalyzer (Agilent Technologies, Santa Clara CA). Quantitative Real-Time polymerase chain reaction (qRT-PCR) assays were formatted into a TaqMan low-density array (TLDA; Applied Biosystems), which was performed at the Shannon McCormack Advanced Molecular Diagnostics Laboratory Research Services, Dana Farber Cancer Institute, Harvard Clinic and Translational Science Center. The normalized microarray data were managed and analyzed by Statminer version 3.0. The targets of miRNA were predicted by using computational approaches, the MicroCosmTargets version 5 and miRBase. The pathway was analyzed by commercial available Ingenuity software. Finally the target predicted was validated by qRT-PCR and imunohistochemistry. The results showed that 101 miRNAs are differentially expressed in the patients of CC compared with PSC, of which 86 (85%) miRNAs were down-regulated in CC patients, suggesting a majority of regulators in the poor prognosis of CC are tumor suppressors. The key miRNAs that were down-expressed in CC patients are miR-9, miR-202, miR-488, miR-509–5p and up-expressed are miR-217, and miR-550. Hundred of gene targets and protein target on the pathways were predicted, but the top targets are enhancer of polycomb homolog 1 (EPC1) and mycophyta (c-MYC), which were validated by qRT-PCR assay at mRNA level and confirmed by immunohistochemistry at molecules level. We identified the key miRNAs that differentially expressed in patients of CC and PSC tumors, predicted and validated the most popular targets regulated by the key miRNAs, indicating the possible regulation gene and pathway for EOC prognosis. This work was supported by the Ministry of Science and Technology of China, Program No. 2008DFA30720 to Shiying Cui. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2011 Nov 12-16; San Francisco, CA. Philadelphia (PA): AACR; Mol Cancer Ther 2011;10(11 Suppl):Abstract nr C154.