Abstract 2989: MicroRNA profiling in human samples and cell lines uncovers eight key players in the cisplain resistance of HGSOC

Abstract Metastasis and drug resistance remain significant contributors to cancer-related mortality globally. In ovarian cancer, a substantial 70% of cases develop resistance to the front-line therapy, cisplatin. Despite numerous proposed mechanisms for cisplatin resistance, the complete molecular events leading to this phenomenon in ovarian cancer remain incompletely understood. Mounting evidence suggests that dysregulation of microRNAs (miRNAs) plays a pivotal role in carcinogenesis, including the development of drug resistance. While various miRNAs have been identified in ovarian cancer samples and cell lines, few studies have compared miRNA expression in human paraffin ovarian samples and cisplatin-resistant high-grade serous ovarian cancer (HGSOC), the most prevalent and malignant of gynecological malignancies. This study aimed to identify key miRNAs implicated in cisplatin resistance. We performed miRNA expression profiles in RNA isolated from human paraffin ovarian tumors and ovarian cancers cell lines. Eight miRNAs were commonly increased in paraffin samples and cisplatin resistant ovarian cancer cells. Targeting these miRNAs with inhibitors significantly reduced cell proliferation by more than 50% for miR-203a, miR-96-5p, miR-10a-5p, miR-141-3p, miR-200c-3p, and miR-182-5p, and to a lesser extent, miR-296-5p and miR-1206. Inhibitors demonstrated a reduction in cell migration for all targets except miR-200c-3p and miR-10a-5p. Analysis of online databases, literature reports, and molecular pathway construction revealed that these eight miRNAs regulate key molecular pathways associated with cell proliferation, primarily through PTEN regulation in cisplatin-resistant HGSOC cells. Interrogation of the KM plotter patient database revealed that high expression of miR-1206, miR-10a, miR-141, and miR-96 correlates with a poor prognosis in ovarian cancer patients. These findings position these eight miRNAs as potential therapeutic targets and markers for cisplatin response in ovarian cancer therapy. Citation Format: Mariela Rivera-Serrano, Marienid Flores, Jose Rolon, Victor Reyes, Fatma Valiyeva, Pablo E. Vivas-Mejia. MicroRNA profiling in human samples and cell lines uncovers eight key players in the cisplain resistance of HGSOC abstract. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts) ; 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84 (6Suppl): Abstract nr 2989.