Abstract B40: MiR-30c-2-3p participates in a regulatory feedback loop to inhibit the progression of chemoresistant ovarian cancer cells

Although many patients achieve a period of remission, serous epithelial ovarian carcinoma remains incurable because untreatable chemoresistant disease develops after first-line chemotherapy. The general lack of knowledge in understanding the molecular mechanisms that evolve in chemoresistance and the absence of ‘targetable’ molecules to exploit therapeutically is a major obstacle preventing an improvement in mortality. MicroRNAs (miRNAs) are naturally-produced, small noncoding RNA molecules that modulate gene transcription by fine-tuning messenger RNA (mRNA) expression and acting as mRNA co-repressors or co-activators. The mitogenic lipid, lysophosphatidic acid, and the epidermal growth factor mediate a significant increase in miR-30c-2-3p, which then participates in a regulatory feedback loop to inhibit viability, growth and proliferation of both chemo-sensitive and –resistant cells. Because a single miRNA can target hundreds of transcripts, we wanted to understand which mRNAs are targeted by miR-30c-2-3p and what is the extent of its ability to alter normal processes like survival, growth and proliferation through post-transcriptional modifications. In our study, we uncovered that miR-30c-2-3p targets the oncogene transcript for BCL9, which is a protein that promotes tumor progression, proliferation and metastasis. We hypothesize that the perpetuation of incessant, extracellular, mitogenic signaling overwhelms the anti-growth feedback loop mechanism supported by miR-30c-2-3p. Thus, the growth factor lysophosphatidic acid, which is abundantly present in ascites fluid, is a significant barrier to the successful treatment of chemoresistant ovarian tumors. Our data will demonstrate the effects of lysophosphatidic acid in both in vitro and in vivo models of ovarian cancer. Our long-term goal is to better understand the molecular mechanisms which evolve simultaneously with chemoresistance in ovarian tumor progression.

Citation Format: Mandi Murph, Wei JIa, Molly Altman, Ha Nguyen. MiR-30c-2-3p participates in a regulatory feedback loop to inhibit the progression of chemoresistant ovarian cancer cells. [abstract]. In: Proceedings of the AACR Special Conference on Advances in Ovarian Cancer Research: From Concept to Clinic; Sep 18-21, 2013; Miami, FL. Philadelphia (PA): AACR; Clin Cancer Res 2013;19(19 Suppl):Abstract nr B40.