抑制polo-like kinase-1基因表达对5-氟脲嘧啶及顺铂体外诱导胃癌细胞凋亡的影响

目的观察抑制polo-like kinase-1(Plk-1)基因对5-氟脲嘧啶(5-Fu)及顺铂(CDDP)体外诱导胃癌细胞株-MKN45凋亡的影响。方法小片断干扰RNA(siRNA)阻断MKN45细胞Plk-1 基因的表达;定量PCR及Western blot检测Plk-1表达的变化;MTT法检测MKN45细胞增殖速率;流式细胞仪检测MKN45细胞凋亡率。结果经靶向Plk-1的siRNA作用24 h、48 h及72 h后,Plk-1 mRNA水平分别下降了51．91％、89．45％、91．03％,蛋白水平在48 h及72 h分别降低了38．43％和 60．66％;联合应用5-Fu、CDDP与靶向Plk-1 siRNA组的MKN45细胞增殖速率较单用5-Fu、CDDP或靶向Plk-1 siRNA组明显减慢(P<0．05);在48 h及72 h细胞凋亡率明显上升(P<0．05)。结论 Plk-1基因表达抑制在体外可增强5-Fu及CDDP对MKN45细胞的凋亡诱导作用;联合应用靶向Plk-1 的siRNA有可能提高5-Fu及CDDP对胃癌细胞杀伤作用。

Inhibition of Plk-1 gene expression enhences 5-Fu and CDDP induced apoptosis of gastric cancer cells

Objective To observe the effect of inhibition of polo like kinasel (Plk-1) gene expression on 5-Fu and CDDP induced apoptosis of gastric cancer cell line-MKN45 in vitro. Methods The Plk-1 expression was inhibited by chemically synthesized siRNA, the Plk-1 mRNA and protein level were measured by real-time PCR and Western blotting, MKN45 cells proliferation was measured by MTT method, the apoptosis rate was detected by flow-cytometry. Results After treatment by siRNA targeting Plk-1, Plk-1 mRNA level decreased by 51.91% .89.45%.91.03% at 24 h.48 h and 72 h, and Plk-1 protein level decreased by 38.43% and 60.66% at 48 h and 72 h, compared with control group. The proliferation of MKN45 cells treated by a combination of 5-Fu, CDDP and Plk-1 siRNA significantly slowed down when compared with treatment of 5-Fu, CDDP or Plk-1 siRNA(P<0.05) individually, apoptosis rate was increased substantially at 48 h and 72 h (P<0.05). Conclusions Inhibition of Plk-1 gene expression can enhance 5-Fu and CDDP induced apoptosis in MKN45 cells in vitro, combined application of Plk-1 siRNA improves killing effect of 5-Fu and CDDP on gastric cancer cells.