The Study Of PRRX1 Promotes Breast Cancer Epithelial Cell Occur EMT To Tamoxifen Resistance

【Objective】To investigate the effect of PRRX1 on EMT and the resistant ability to tamoxifen of breast cancer epithelial cell.【Methods】1.PRRX1 and black vector were transfected into PRRX1 low expression cell line MCF-7 cells by liposome transfection,the experimental group was the cells transfected with the PRRX1 gene,the blank control group was the cells transfected with a control plasmid empty vector,and the negative control group was MCF-7 cells.2.Verified to be accomplished through Western-blot and Real-time PCR.3.Observe the cell morphology and transfection efficiency under inverted fluorescence microscope after 24 hours.4.The effect of PRRX1 gene on the expression of Vimentin and E-cadherin（E-cad）mRNA was detected by Real-time PCR to verify whether the experimental group cells occurs epithelial-mesenchymal transition.5.Verified the expression of ER through Western-blot and investigate the effect of PRRX1 gene on ER protein expression.6.Cytotoxicity was detected by CCK-8 after exposure to tamoxifen 24h at last.【Results】After MCF-7 cells were transfected by PRRX1,the fluorescence efficience reached more than 80%.The morphology of the cell changes from a paving stone that is tightly connected before transfection to a loose spindle cell.Western blot results shaowed that the expression of PRRX1 in experimental group cell was significantly higher than control group cells（P<0.001）,while two control group cells no statistically significant（P>0.05）.Real-time PCR results show that the（35）CT of PRRX1 mRNA in experimental group、blank control group and negative control group are（5.20±0.231）、（13.77±0.642）、（13.50±0.360）,the expression in experimental group cell was significantly higher than control group cells（P<0.001）,while two control group cells no statistically significant（P>0.05）.The（35）CT of E-adherin mRNA in experimental group、blank control group and negativecontrol group are（19.39±0.400）、（18.61±0.108）、（18.47±0.076）,the expression experimental group cell was significantly lower than control group cells（P<0.001）,while two control group cells no statistically significant（P>0.05）.The（35）CT of vimentin mRNA in experimental group、blank control group and negativecontrol group are（17.82±0.061）、（19.48±0.021）、（19.42±0.082）,The expression of ER in experimental group cell was significantly lower than control group cells（P<0.001）,while two control group cells no statistically significant（P>0.05）.the expression in experimental group cell was significantly higher than control group cells（P<0.001）,while two control group cells no statistically significant（P>0.05）.CCK-8 results showed that,after the action of tamoxifen,the IC₅₀0 of experimental group cell was significantly higher than the two control group cells（P<0.001）,while two control group cells no statistically significant（P>0.05）.【Conclusion】PRRX1 can enhance tamoxifen resistance of MCF-7 cells by inducing EMT.