幽门螺杆菌感染对胃癌细胞株增殖及凋亡影响的研究

Effect of helicobacter pylori infection on cell proliferation and apoptosis of gastric cancer SGC-7901

目的探讨幽门螺杆菌感染对胃癌细胞株SGC7901增殖和凋亡的影响和机制。方法体外培养的SGC7901细胞与1×10^8、5×10^7、1×10^7、5×10^6cfu／ml浓度梯度的HPNCTC11637标准菌株共孵育，分别在24、48、72h时观察细胞形态学变化，MTT检测细胞增殖抑制率，流式细胞和TUNEL分析细胞凋亡，RT-PCR检测survivin在mRNA的表达情况，Western blot检测细胞survivin在蛋白水平的表达。结果1×10^8、5×10^7、1×10^7、5×10^6cfu／ml浓度梯度的HP菌对SGC7901细胞作用72h的细胞增殖抑制率分别为54．5％、58．9％、67．6％、72．9％。流式细胞仪和TUNEL法检测不同浓度梯度的HP菌处理72h后细胞凋亡率分别为42．51％、45．67％、48．57％、54．61％与49．51％、51．26％、59．41％、62．46。幽门螺杆菌可以明显降低survivin的mRNA和蛋白水平的表达。这些作用均随幽门螺杆菌浓度和作用时间的延长而增强。结论幽门螺杆菌感染可能通过降低survivin的表达，在体外抑制SGC7901细胞增殖，并促进其凋亡。并且，这种作用呈时间剂量效应。

Objective To investigate the effect of Helicobacter pylori infection on cell proliferation and apoptosis of gastric cancer cell line SGC 7901. Method SGC 7901 cells were incubated with 1×10^8、5×10^7、1×10^7、5×10^6cfu / ml concentration gradient of the standard HP NCTC 11637 strains in vitro. Morphological changes of cells were observed at 24, 48, 72 hour, respectively. Cell proliferation inhibition rate were detected with MTT assay. Apoptosis were observed by flow cytometry and TUNEL analysis, mRNA expression of survivin were detected by RT-PCR, and survivin expression were determined by western blot. Results Cell proliferation inhibition rate was 54. 5%, 58.9% , 67. 6%, 72. 9% with 1×10^8、5×10^7、1×10^7、5×10^6 efu / ml concentration gradient of the HP bacteria on the role of SGC 7901 cells at 72h, respectively. The rate of apoptosis after 72h detected by flow cytometry and TUNEL with HP concentration gradient of different bacteria were 42. 51%, 45.67%, 48.57%, 49.51% and 54. 61%, 51.26%, 59.41%, 62. 46. % Helicobacter pylori could significantly reduce mRNA and protein expression of survivin. These effects were strengthened as the concentration of Helicobacter pylori increased and the time extended. Conclusion H. pylori infection may be through reducing the expression of survivin to inhibit cell proliferation and promote apoptosis of SGC 7901 in vitro. Moreover, this effect was positive related with time and dose.