MiR-200c Regulates Migration Of Breast Cancer Cell BT549 By Targeting Slug

Breast cancer is one of the common malignant tumors in female. In China, the incidence of breast cancer accounts for 7% ~10%, and a report about some big cities indicated that the breast cancer ranked in the first place among malignant tumors in female. According to St Gallen’s consensus about the breast cancer molecular classification, the breast cancer can be divided into luminal A, luminal B, Her-2 positive and basal-like in accordance with estrogen receptor(ER), progesterone receptor(PR) and human epidermal growth factor receptor(Her2). The basal-like breast cancer cell do not express ER, PR and Her2, with strong invasion, and do not have inefficiency in endocrinology and molecular therapy.Snail is the most important E-cadherin transcription inhibitor discovered at first and E-cadherin is closely related to epithelial-mesenchymal transition(EMT). mi Rs are kinds of small molecular RNAs discovered in recent years, which regulate the expression of protein by post-transcriptional mechanisms. A research have showed that mi R-200 family in spongioblastoma and prostate cancer cells could increase the expression of E-cadherin by regulating Slug so as to suppress EMT and block cell migration. However,it is not reported whether the correlation of mi R-200 c in the basal-like breast cancer cells and Slug exists and whether increment of E-cadherin through suppressing Slug can inhibit EMT. This study have discovered that mi R-200 c in basal-like breast cancer cell could combine with Snail2(Slug) which belonged to Snail family through gene analysis and predication.Objective This study regarded breast cancer BT549 cell as the research object and transferred mi R-200 c into the breast cancer cell BT549 to explore the relationship of mi R-200 c and the expression of Slug and the influence of mi R-200 c to the migration of BT549 cell in order to provide laboratory basis for clinical diagnosis and treatment.Methods 1 We designed the mi R-200 c mimic and transfected it into a highly metastatic breast cancer cell line BT549(From ATCC)which was cultured through RPMI 1640 medium within 10% fetal bovine serum.The experiment was divided into 3 groups: mi R-200 c group,mi R-control group and blank control group. 3 wells were prepaired in every group. 2 We utilized Transwell migration assay and wound healing assay to research the influence of mi R-200 c to the migration ability of breast cancer cell BT549; 3 We adopted real time PCR to detect the expression change of mi R-200 c to Slug m RNA and E-cadherin m RNA in breast cancer cell BT549; 4 We employed Western blot assay to detect the expression change of mi R-200 c to slug in breast cancer cell BT549.Results 1 Compared with blank control groups and mi R-control group, the migration ability of the BT549 cell in mi R-200 c group was reduced and the difference had statistical significance(P=0.000); 2 Compared with blank control group and mi R-control group, the expression of Slug m RNA in the BT549 cell of mi R-200 c group was decreased and the difference had statistical significance(P=0.002), but the expression of E-cadherin m RNA was increased and the difference had the statistical significance(P=0.004); 3 Compared with blank control group and mi R-control group, the expression of Slug in the BT549 cell of mi R-200 c group was declined and the difference had the statistical significance(P=0.000).Conclusions mi R-200 c in breast cancer cell BT459 could reduce the expression of correspondent Slug protein by suppressing the translation of Slug m RNA and then promote the expression of E-cadherin and inhibit EMT and block the migration of BT549 cell.