title: miR-222 is upregulated in epithelial ovarian cancer and promotes cell proliferation by downregulating P27kip1.
abstract: Epithelial ovarian cancer (EOC) is the leading cause of female reproductive system cancer mortality in females. The majority of cases of ovarian carcinomas are not identified until a late stage. Identifying the molecular changes that occur during the development and progression of ovarian cancer is an urgent requirement. MicroRNAs (miRNAs) have been identified as gene expression regulators that induce mRNA degradation or translation blockade through pairing to the 3' untranslated region (3-'UTR) of the target mRNAs. In the present study, miR-222 was observed to be frequently upregulated in ovarian cancer. miR-222 upregulation induced an enhancement of ovarian cancer cell proliferation potential, possibly by downregulating its target, P27Kip1. A bioinformatic analysis showed that the 3'-UTR of the P27Kip1mRNA contained a highly-conserved putative miR-222 binding site. Luciferase reporter assays demonstrated that P27Kip1was a direct target of miR-222. Consistently, there was an inverse correlation between the P27Kip1and miR-222 expression levels in the ovarian cancer cell lines and tissues. Overall, the present results suggest that miR-222 upregulation in human ovarian cancer may promote ovarian cancer cell proliferation during ovarian carcinogenesis.
authors.affiliation: Cancer Biology Research Center, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei 430030, P.R. China.
authors.forename: Chaoyang
authors.initials: C
authors.lastname: Sun
authors.forename: Na
authors.initials: N
authors.lastname: Li
authors.forename: Bo
authors.initials: B
authors.lastname: Zhou
authors.forename: Zongyuan
authors.initials: Z
authors.lastname: Yang
authors.forename: Dong
authors.initials: D
authors.lastname: Ding
authors.forename: Danhui
authors.initials: D
authors.lastname: Weng
authors.forename: Li
authors.initials: L
authors.lastname: Meng
authors.forename: Shixuan
authors.initials: S
authors.lastname: Wang
authors.forename: Jianfeng
authors.initials: J
authors.lastname: Zhou
authors.forename: Ding
authors.initials: D
authors.lastname: Ma
authors.forename: Gang
authors.initials: G
authors.lastname: Chen
keywords: P27Kip1; carcinogenesis; epithelial ovarian cancer; miR-222