BMP9 Inhibits The Migration And Invasion Of Breast Cancer Cell Through Down-regulating LncRNA ITGB2-AS1

Objective:The previous findings of our research group show that BMP9 has a inhibitory effect on breast cancer,but its underlying mechanism is still unknown.In this article the mechanism is investigated from the perspective of lncRNA ITGB2-AS1 and its target gene ITGB2.Methods: Gene chip was used to detect the expression of lncRNA in breast cancer MDA-MB-231 cells before and after BMP9 treatment.The data was screened and then validated by Q-PCR.After further bioinformatics analysis and prediction,LncRNA ITGB2-AS1 was selected as the research object.The plasmid was transfected into MCF-7 cell to construct overexpression cell line and the siRNA was transfected into MDA-MB-231 cell line to konck down its expression.MTT assay and Flow cytometry were used to measure the viability and cycle of breast cancer cells;cell migration and invasion were tested by wound healing assay and Transwell chamber assay respectively.Then the correlation between ITGB2-AS1 and ITGB2 was analyzed by bioinformatics and verified by Q-PCR and WB experiments.ITGB2 overexpression recombinant plasmid was constructed and the effect of ITGB2 on breast cancer was further studied by above biological function experiments.Segmented plasmid of ITGB2-AS1 plasmid was consturcted and the related pathway was detected by WB.Breast cancer cells were co-transfected with BMP9 adenovirus and ITGB2-AS1 plasmid to detect the migration again by wound healing assay.Results: The four LncRNA ITGB2-AS1、Loc100128593、SHNG11 and TP53TG1 were selected for validation by Q-PCR.The recombiant cell line was validated by Q-PCR.Bioinformatics analysis showed that there was a positive correlation between ITGB2-AS1 and breast cancer.The results of MTT and FCM implied that lncRNA ITGB2-AS1 had no effect on cell viability and cycle.Wound healing assay and Transwell chamber assay demonstrated that ITGB2-AS1 can significantly increase the migration and invasion of breast cancer.Bioinformatics analysis showed that there was a positive correlation between ITGB2-AS1 and ITGB2 expression in breast cancer tissues.PCR and WB experiments further confirmed that ITGB2-AS1 could promote the expression of ITGB2 in breast cancer cells.Overexpression of ITGB2 could promote the migration and invasion of breast cancer cells.And the promotion of breast cancer by lncRNA ITGB2-AS1 and ITGB2 were related to the activation of FAK pathway.The activation of FAK signaling by ITGB2-AS1 was mainly through the fragment complementary to ITGB2.The wound healing assay demonstrated that co-transfection of BMP9 and ITGB2-AS1 could reduce the inhibitory effect of BMP9 on the migration of breast cancer.Conclusions: BMP9 could inhibit the migration and invasion of breast cancer through down-regulating LncRNA ITGB2-AS,and its underlying mechanism may be related to FAK signaling.