miR-93/miR-106b/miR-375-CIC-CRABP1: a novel regulatory axis in prostate cancer progression

// Nahyun Choi 1 , Jongmin Park 1 , Jeon-Soo Lee 1 , Jeehyun Yoe 1 , Guk Yeol Park 1 , Eunjeong Kim 1 , Hyeongrin Jeon 2 , Yong Mee Cho 3 , Tae-Young Roh 1,2 and Yoontae Lee 1,2 1 Department of Life Sciences, Pohang University of Science and Technology, Pohang, Kyungbuk, Republic of Korea 2 Division of Integrative Bioscience and Biotechnology, Pohang University of Science and Technology, Pohang, Kyungbuk, Republic of Korea 3 Department of Pathology, University of Ulsan College of Medicine, Asan Medical Center, Seoul, Republic of Korea Correspondence to: Yoontae Lee, email: // Keywords : prostate cancer, capicua, ETV5, CRABP1, microRNA Received : March 30, 2015 Accepted : May 30, 2015 Published : June 08, 2015 Abstract Capicua (CIC) has been implicated in pathogenesis of spinocerebellar ataxia type-1 (SCA1) neurodegenerative disease and some types of cancer; however, the role of CIC in prostate cancer remains unknown. Here we show that CIC suppresses prostate cancer progression. CIC expression was markedly decreased in human prostatic carcinoma. CIC overexpression suppressed prostate cancer cell proliferation, invasion, and migration, whereas CIC RNAi exerted opposite effects. We found that knock-down of CIC derepresses expression of ETV5 and CRABP1 in LNCaP and PC-3 cells, respectively, thereby promoting cell proliferation and invasion. We also discovered that miR-93, miR-106b, and miR-375, which are known to be frequently overexpressed in prostate cancer patients, cooperatively down-regulate CIC levels to promote cancer progression. Altogether, we suggest miR-93/miR-106b/miR-375-CIC-CRABP1 as a novel key regulatory axis in prostate cancer progression.