miR-34a mediates the multidrug resistance of breast cancer by regulating the expression of downstream gene / 临床检验杂志

ABSTRACT

Objective@#To identify the therapeutic target of multidrug resistance of breast cancer by investigating the regulatory mechanism of the abnormal expression of miR-34a and FUT8 on the multidrug resistance of breast cancer. @*Methods@#The expression levels of miR-34a and FUT8 in MCF-7 and MCF-7/ADR cells were detected by the real-time PCR and western blot. The transfection efficiency of miR-34a in breast cancer cells was determined by the real-time PCR. The targeting relationship between miR-34a and FUT8 was predicted by the bioinformatics method, and further verified by the dual-luciferase reporter assay. After the expression of miR-34a was specifically regulated, the changes of FUT8 mRNA and protein levels in transfected cells were detected by the real-time PCR, Western blot and immunofluorescence staining, respectively. After the expression of miR-34a was specifically regulated, the proliferation and multidrug resistance of MCF-7 and MCF-7/ADR cells were determined by the CCK8 and immunofluorescence assays. @*Results@#The expression levels of miR-34a in MCF-7 cells were significantly higher than that in MCF-7/ADR cells ( P =0.002 6). The expression levels of FUT8 gene in MCF-7/ADR cells were significantly higher than that in MCF-7 cells ( P =0.001 6). FUT8 was the target of miR-34a regulating the drug resistance of breast cancer ( P =0.001 9). The up-regulation of miR-34a in MCF-7/ADR cells could significantly inhibit the expression of FUT8 , and the multidrug resistance and proliferation of MCF-7/ADR cells. While, the down-regulation of miR-34a increased the expression of FUT8 , and enhanced the multidrug resistance and proliferation of MCF-7 cells. @*Conclusion@#MiR-34a mediates the multidrug resistance of breast cancer by regulating the expression of downstream gene FUT8 .