PTEN下调paxillin的表达抑制胃癌转移

目的检测PTEN(phosphatase and tensin homolog deleted on chromosome10,10号染色体缺失的磷酸酶与张力蛋白同源物)及桩蛋白(paxillin)在胃癌细胞系BGC823中的表达,并探讨PTEN对paxillin的调节作用及其在胃癌的发生、发展中的意义。方法体外培养胃癌细胞BGC823,利用脂质体介导法瞬时转染pEAK8及pEAK8-PTEN质粒,获得pEAK8-BGC823(pE-B)和pEAK8-PTEN-BGC823(pE-P-B)细胞,采用免疫印迹法检测PTEN、paxillin及actin蛋白水平的表达,免疫荧光检测paxillin在细胞内的定位。结果 Western blot显示,pE-P-B细胞PTEN蛋白表达水平(1.013±0.074)明显高于pE-B细胞(0.513±0.006)和BGC823细胞(0.506±0.015),而paxillin的蛋白表达水平(0.883±0.032)明显低于后两者(2.747±0.047,2.663±0.096),BGC823与pE-B相比,PTEN和paxillin蛋白表达差异均无统计学意义(P>0.05),Sperman等级相关分析证明PTEN蛋白与paxillin蛋白的表达呈负相关(r=-0.12,P<0.05);免疫荧光显示,paxillin在pE-B细胞伸出伪足处聚集,在pE-P-B细胞中较少。结论过表达PTEN可能通过下调paxillin的表达从而抑制胃癌的转移。

PTEN down-regulating the expression of paxillin to inhibit metastasis of gastric cancer

Objective To detect the expression of phosphatase and tensin homolog deleted on chromosome 10(PTEN) and paxillin in gastric cancer cell line BGC823,and explore the regulation effect of PTEN to paxillin in the generation and development of gastric cancer.Methods The gastric cancer cell line BGC823 transfected with pEAK8 and pEAK8-PTEN plasmid transiently was cultivated in vitro to get cells of pEAK8-BGC823(pE-B) and pEAK8-PTEN-BGC823(pE-P-B).Protein expression of PTEN,paxillin and actin were detected by immune imprinting method,and the location of paxillin inside the cell was detected by immunofluorescence.Results Western blot showed that the protein expression of PTEN was obviously higher in pE-P-B(1.013±0.074) than that in pE-B(0.513±0.006) and BGC823 cells (0.506±0.015),while the protein expression of paxillin in pE-P-B(0.883±0.032) was significantly lower than that in other two groups(2.747±0.047,2.663±0.096).Sperman rank correlation analysis showed that the protein expression of PTEN and paxillin were negatively correlated(r=-0.12,P<0.05).Paxillin located in pseudopodia by immunofluorescence in pE-B cells,meanwhile few in pE-P-B cells.Conclusion The over-expression of PTEN can down-regulate the expression of paxillin thus inhibit the metastasis of gastric cancer