关键词: 乳腺癌, lncBRM, 增殖, 侵袭, 迁移, miRNA

Abstract: Objective To investigate the effect of long non-coding RNA for association with Brahma（lncBRM） on the growth，migration，and invasion of human breast cancer cell lines（MCF-7，MDA-MB-453） and its possible mechanism. Methods The expression of lncBRM in different breast cancer cells（MCF-7，ZR-75-30，BT474，MDA-MB-231，and MDA-MB-453） and normal human breast epithelial cell line MCF 10A was detected by RT-PCR. siRNA was used to knock down the expression of lncBRM in MCF-7，MDA-MB-453 cells，and transfect si-lncBRM plasmid（si-lncBRM group） and blank plasmid（si-Ctrl group），respectively. CCK-8 assay was used to detect cell proliferation，and flow cytometry was used to detect cell apoptosis. The alteration of cell migration and invasion was detected by Transwell test. In addition，the changes in the expression of E-cadherin and N-cadherin were detected by Western blot. Target prediction of lncBRM was performed by miRDB database. Results The expression level of lncBRM in all breast cancer cells was significantly higher than that in normal human breast epithelial cell line MCF 10A（P<0.01）. Compared with the si-Ctrl group，lncBRM knockdown can inhibit the proliferation of MCF-7 and MDA-MB-453 cells（P<0.05），and increase the apoptosis rate（P<0.01），the numbers of cell invasion and migration cells were small（all P<0.01）. Meanwhile，the protein expression of E-cadherin increased，while N-cadherin decreased dramatically（all P<0.01）. The miRDB database predicted that lncBRM could target 68 miRNAs，and lncBRM knockdown  could indeed increase the expressions of 4 miRNAs（miR-4646-5p，miR-204-3p，miR-204-5p，and miR-6832-3p）of the top 5 miRNAs. Conclusion  lncBRM may inhibit the proliferation，invasion，and migration of breast cancer cells and induce their apoptosis by regulating the miRNAs.

Key words: Breast cancer, lncBRM, Proliferation, Invasion, Migration, miRNA