Abstract 2457: Epithelial-to-mesenchymal transition and stemness: Key targets of HOTAIR-miR-203 interaction in renal cell carcinoma

Abstract

Abstract Background: Tumor metastasis and recurrence are major obstacles in renal cell carcinoma (RCC) treatment. RCC aggressiveness is highly associated with stemness and epithelial-to-mesenchymal transition (EMT) which involves increased cellular migration, invasion, inhibition of apoptosis and senescence. HOX transcript antisense RNA (HOTAIR), a lncRNA, is reported to be over-expressed, whereas miR-203 has low expression and is a tumor suppressor in various cancers. However, their association and role in RCC is not well understood. The aim of the present study was to examine the interaction of HOTAIR and miR-203 in the regulation of stemness and EMT in RCC. Experimental Procedure: ACHN, Caki-1 (human RCC cell lines), normal renal epithelial cells HK-2 and clinical specimens were used for this study. Profiling of HOTAIR and miR203 expression were done by quantitative real-time PCR and luciferase assay was performed to confirm their interaction. Attenuation of HOTAIR (25nM siRNA) and overexpression of miR-203 (10nM mimic) for 72 hours were used for functional studies. The biological role of miR-203 and its interaction with HOTAIR was also investigated using nude mouse models. Results: HOTAIR was observed to be overexpressed in RCC cell-lines and clinical specimens whereas, miR-203 was significantly under-expressed when compared to normal cells and tissues. Overexpression of miR-203 altered the cell cycle, inhibited epithelial-to-mesenchymal transition (EMT) and decreased cell proliferation along with induction of epithelial marker proteins and decrease in mesenchymal and stemness marker proteins. Conversely, knockdown of miR-203 in non-malignant HK-2 cells induced pro-cancerous characteristics. Direct binding of miR-203 to HOTAIR was shown by RNA immunoprecipitation and luciferase assay. Attenuation of HOTAIR expression reduced cell migration, invasion, and induced apoptosis, mimicking the effects of miR-203 overexpression. Administration of miR-203 mimic to established tumors in nude mice significantly suppressed tumor growth compared to controls. Conclusion: Our results show that HOTAIR-miR-203 interaction inhibits EMT and stemness to regulate RCC progression. Statistical analysis of the clinicopathological data from kidney cancer patients suggests that HOTAIR and miR-203 may be useful in RCC diagnostics and therapeutics. Citation Format: Pritha Dasgupta, Priyanka Kulkarni, Shahana Majid, Varahram Shahryari, Yutaka Hashimoto, Nadeem S. Bhat, Marisa Shiina, Guoren Deng, Sharanjot Saini, Soichiro Yamamura Yamamura, Yuichiro Tanaka, Rajvir Dahiya. Epithelial-to-mesenchymal transition and stemness: Key targets of HOTAIR-miR-203 interaction in renal cell carcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 2457.