MicroRNA-294 Promotes Cellular Proliferation and Motility through the PI3K/AKT and JAK/STAT Pathways by Upregulation of NRAS in Bladder Cancer

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Yongwei Li^1#, Zhengfei Shan^1#, Chu Liu^1#, Diandong Yang^1*, Jitao Wu^1*, Changping Men¹, and Yankai Xu²

¹Department of Urology, The Affiliated Yantai Yuhuangding Hospital of Qingdao University, Yantai 264000, China; E-mail: jtwu1006@163.com

²Department of Urology, Yantai Affiliated Hospital of Binzhou Medical University, Yantai 264100, China

^# These authors contributed equally to this work.

^* To whom correspondence should be addressed.

Received October 10, 2016; Revision received November 18, 2016

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In our study we examined the role of microRNA-294 (miR-294) in bladder cancer and related mechanisms. Real-time polymerase chain reaction (RT-PCR) was performed to determine the expression level of miR-294. Western blot was used to determine the expression of NRAS, mainly factors in the PI3K/AKT and JAK/STAT pathways. Cell counting kit-8 assay, clonogenic assay, wound-healing assay, transwell and flow cytometry were used to explore, respectively, cell proliferation, survival, migration, invasion, and apoptosis of bladder cancer cell line T24. The expressions of miR-294 in bladder cancer cells including J82, HT1376, T24, and SW780 were significantly increased compared to those in human bladder epithelium cells (both HCV29 and SV-HUC-1). The proliferation rate, surviving fraction, migration, and invasion of T24 cells in miR-294 mimetic transfected group were significantly increased, while they were significantly decreased by miR-294 inhibitor transfection. Moreover, miR-294 suppression could increase the apoptotic rate of T24 cells. In addition, drug resistance of T24 cells to cisplatin was increased in miR-294 mimetic-treated group, while it was decreased by miR-294 inhibitor compared to empty control. Overexpression of miR-294 could upregulate NRAS expression in T24 cells and activate PI3K/AKT and JAK/STAT pathways. We found that miR-294 expression was positively related with proliferation and motility of T24 cells. Moreover, miR-294 suppression could promote the sensitivity of T24 cells to cisplatin. We also found miR-294 could upregulate NRAS and activate the PI3K/AKT and JAK/STAT pathways in T24 cells.

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KEY WORDS: microRNA-294, NRAS, PI3K/AKT and JAK/STAT pathways, bladder cancer

DOI: 10.1134/S0006297917040095

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