Abstract: Objective To investigate the effect of PKM2 down-regulation on invasion and migration in tamoxifen-resistant breast cancer MCF-7 cell line. Methods The tamoxifen-resistant breast cancer cell line (MCF-7R) was established by increasing tamoxifen concentration in a stepwise manner. CCK-8 was used to measure the proliferation of cells. The protein expression of PKM2 was determined by Western blot. shRNA for PKM2 gene lentiviral interference vectors were infected into MCF-7R cells, the effect of interference was determined by RT-qPCR and Western blot. Cell invasion and migration abilities were measured by transwell and wound-healing assays. Results The capability of tamoxifen resistance in MCF-7R cells was dramatically enhanced compared to that in MCF-7 cells (P<0.01). Protein level of PKM2 was markedly increased in MCF-7R cells (P<0.01). The mRNA and protein levels of PKM2 declined obviously in PKM2-silented MCF-7R cells (P<0.01). We also demonstrated that knockdown of PKM2 significantly inhibit the invasion and migration of MCF-7R cells (P<0.01). Conclusions The expression of PKM2 is apparently higher in MCF-7R than that in MCF-7 cells. Moreover, knockdown of PKM2 can inhibit the migration and invasion of MCF-7R cells.

Key words: Breast cancer, Tamoxifen, pyruvate kinase M2, invasion, migration