MiR-202-3p Regulates MMP1 To Reverse Adriamycin Resistance In Breast Cancer Cells

Objectibve: To investigate the relationship between miR-202-3p expression in breast cancer MCF-7/ADR cells and its association with doxorubicin resistance.Methods:(1)predicting target genes binding to miR-202-3p from targetscan,miRDB,PICTAR and other gene databases;(2)breast cancer cells(MCF-7)and breast cancer doxorubicin resistant strains(MCF-7/ADR)Transfection of predicted miRNA mimics(miRNA-202-3p mimics),miRNA mimetic negative control(miRNA-202-3p mimics-NC),miRNA inhibitors(miRNAs)by plasmid transient transfection-202-3p inhibitor),miRNA inhibitor negative control(miRNA-202-3p inhibitorNC),blank control(BC),miRNA inhibitor + target gene silencing group(miRNA-202-3p inhibitor + siRNA),and The two cells were divided into six groups according to the above transfection method(mimics group,mimics-NC group,inhibitor group,inhibitor-NC group,BC group,inhibitor+siRNA group);(3)QRT-PCR method for detecting MCF-7 And MCF-7/ADR cells were transfected into the six groups of cells before and after miRNA-202-3p,and the difference in expression of target genes predicted in step(1);(4)MTT assay for MCF-7 and MCF-7/ADR The proliferation of seed cells in 7 different concentrations of doxorubicin(5,10,20,40,80,160,320 mg / mL);(5)The expression of downstream proteins of target genes in MCF-7 and MCF-7/ADR cells was detected by western blot.Results:(1)qRT-PCR results showed that the relative expression level of miR-202-3p in MCF-7 cells was 4.49±0.60 times higher than that in MCF-7 /ADR cells.The relative expression of MMP1 mRNA in MCF-7 /ADR was 3.84±0.23 times as high as that in MCF-7 cells.(2)MTT results showed that overexpression of miR-202-3p reduced adriamycin resistance in MCF-7 /ADR cells;Silencing or down-regulating the expression of MMP1 can increase the resistance of MCF-7 /ADR to adriamycin.(3)Western blotting results showed that overexpression of miR-202-3p reduced the expression of MMP1 protein.Conclusion: miR-202-3p may reverse the resistance of MCF-7/ADR cells to doxorubicin by down-regulating the expression of MMP1.