title: MicroRNA-34c Suppresses Breast Cancer Migration and Invasion by Targeting GIT1.
abstract: Abnormal expression of microRNAs plays important role in tumor metastasis. Migration and invasion of cancer cells accord for the metastasis and deterioration of breast cancer. However, the regulatory role of microRNAs in the invasion and migration of breast cancer cells has not completely understood yet. Here we found that microRNA-34c (miR-34c) was significantly downregulated in metastatic tissue of breast cancer.In vitrostudy showed that miR-34c negatively regulated GIT1 protein expression by binding to the 3'UTR of GIT1 mRNA. Consistently, GIT1 protein expression was found upregulated significantly in metastatic breast cancer. Moreover, miR-34c overexpression suppressed the expression of GIT1 protein, and this effect was restored by AMO-miR-34c in breast cancer cells. Overexpression of miR-34c suppressed cell migration and invasion in both MCF-7 and MDA-MD-231 breast cancer cells. Furthermore, knockdown of endogenous GIT1 expression reduced the migration and invasion of both two breast cancer cells. Collectively, miR-34c downregulation in breast cancer cells resulted in the upregulation of GIT1, which in turn enhanced the migration and invasion of breast cancer. This study highlights molecular mechanism of migration and invasion of breast cancer cells.
authors.affiliation: Department of Breast Surgery, Harbin Medical University Cancer Hospital, Harbin, China;; Key Laboratory of Cardiovascular Medicine Research (Harbin Medical University), Ministry of Education, Harbin, China.
authors.forename: Wei-Yang
authors.initials: WY
authors.lastname: Tao
authors.affiliation: Key Laboratory of Cardiovascular Medicine Research (Harbin Medical University), Ministry of Education, Harbin, China;; Department of Urology, The First Affiliated Hospital of Harbin Medical University, Harbin, China.
authors.forename: Chun-Yang
authors.initials: CY
authors.lastname: Wang
authors.affiliation: Department of Breast Surgery, Harbin Medical University Cancer Hospital, Harbin, China.
authors.forename: Yong-Hui
authors.initials: YH
authors.lastname: Sun
authors.affiliation: Department of Breast Surgery, Harbin Medical University Cancer Hospital, Harbin, China.
authors.forename: Yong-Hui
authors.initials: YH
authors.lastname: Su
authors.affiliation: Department of Breast Surgery, Harbin Medical University Cancer Hospital, Harbin, China.
authors.forename: Da
authors.initials: D
authors.lastname: Pang
authors.affiliation: Department of Breast Surgery, Harbin Medical University Cancer Hospital, Harbin, China.
authors.forename: Guo-Qiang
authors.initials: GQ
authors.lastname: Zhang
keywords: GIT1; breast cancer; metastasis.; miR-34c