EFFECT OF NEGATIVE REGULATION OF MIR-217 ON HETEROMUCIN (MTDH) EXPRESSION ON THE SENSITIVITY OF CHEMOTHERAPEUTIC DRUGS IN PROSTATE CANCER PC-3 CELLS

Tao Zhang, Zonglin Wu, He Geng^*

Department of Urology, Putuo People's Hospital of Tongji University, Shanghai, PR China

Objective: To analyse the effect of the negative regulation of miR-217 on heteromucin (MTDH) expression, which affects the sensitivity of chemotherapeutic drugs in prostate cancer PC-3 cells. 

Methods: Eight individuals who had undergone prostate cancer surgery at our hospital’s urology surgery department between May 2017 and June 2018 were selected for the study, and paracancerous normal tissue was collected. miR-217 and MTDH expressions in prostate cancer tissue and paracancerous tissue were detected using real-time quantitative PCR. Overexpression of miR-217 was used to transfect PC-3 cells. The expression of MTDH mRNA and protein after transfection in PC-3 cells was detected by real-time quantitative PCR and the western-blot test. PC-3 cells were divided into the PC-3 cell group (group a), PC-3 cells + miR-217 overexpression transfection group (group b), PC-3 cells + miR-217 overexpression transfection + cisplatin (group c), PC-3 cells + cisplatin (group d), PC-3 cells + MTDH gene intervention (group e), and PC-3 cells + MTDH gene intervention + cisplatin group (group f); the cell-survival rates of each group were detected using MTT assay. 

Results: The expression of miR-217 in prostate cancer tissue was significantly lower than that in paracancerous tissue (P<0.01). The expression of MTDH mRNA in prostate cancer tissue was significantly higher than that in paracancerous tissue, and the difference was statistically significant (P<0.05). The results of regression analysis showed that the regression equation was y = –2.48x + 11.89, R = –0.79; miR-217 and MTDH mRNA were significantly negatively correlated in prostate cancer tissue. The results of real-time quantitative PCR showed that the expression of MTDH mRNA in the transfection group was significantly lower than that in the control group (P<0.01). The results of the western-blot analysis showed that the expression of MTDH protein in the transfection group was significantly lower than that in the control group, and the difference was statistically significant (P<0.01). The cell survival rates of groups b, c, d, e, and f were significantly lower than those of group a, and the difference was statistically significant (P<0.05). The cell survival rates of groups c and f were significantly lower than those of group d (P<0.05). The cell survival rate in group c was significantly lower than that in groups e and f (P<0.05). 

Conclusion: There is a significant negative correlation between the expression of miR-217 and MTDH in prostate cancer tissue. Up-regulating miR-217 can effectively reduce MTDH expression, and can increase the sensitivity of prostate cancer cells to cisplatin chemotherapy.