miR-106b promotes proliferation and invasion by targeting Capicua through MAPK signaling in renal carcinoma cancer

Background: miR-106b has been reported to play a vital role in pathogenesis of some types of cancer, whilst the role of miR-106b in renal carcinoma cancer (RCC) remains unknown. Purpose: The objective of this study was to identify the mechanism of miR-106b regulating the progression of renal carcinoma. Method: The expression of miR-106b was analyzed in RCC cell lines, RCC and adjacent normal renal tissues through qRT-PCR assays. Target mRNA of miR-106b was predicted with databases and verified by luciferase reporter assays. And the effects of miR-106b or targeted mRNA on cell proliferation, invasion, the process of epithelial-mesenchymal transitions (EMTs) were assessed in vitrothrough CCK-8, transwell cell invasion assays, qRT-PCR and Western blotting assays respectively. In addition, the effects of miR-106b on the growth of xenografts mice were analyzedin vivo. Results: The results demonstrated that miR-106b was significantly increased both in RCC tissues and cell lines. Luciferase reporter assays revealed that miR-106b inhibited Capicua expression by targeting its 3ʹ-UTR sequence. And miR-106b promoted cell proliferation, invasion, EMT progression in RCC cellin vitro, as well as promoted the tumor growth of 786-O cells derived xenografts mice. Additionally, loss of Capicua promoted the activation of MAPK signaling pathway. Conclusion: The study suggested that miR-106b regulated RCC progression through MAPK signaling pathway partly by targeting Capicua, which might provide valuable evidence for therapeutic target development of RCC.