刚地弓形虫培养上清抑制肺癌A549细胞系增殖

Supernatant of Toxoplasma gondii culture inhibits the proliferation of human lung cancer cell line A549

目的研究刚地弓形虫(Toxoplasma gondii)培养上清对体外培养的肺癌细胞A549增殖及细胞周期的影响。方法取对数生长期的A549细胞(浓度为5×104mL-1)分别接种于不同细胞培养板,对照组加入RPMI-1640孵育,试验组加入相同体积不同数量(4×107mL-1、8×107mL-1、16×107mL-1)弓形虫速殖子培养上清孵育不同时间后,四甲基氮噻唑蓝(MTT)法检测吸光度(A490值);PI染色后检测细胞周期;以Western blot检测细胞周期蛋白cyclinB1、cdc2表达或活性。结果弓形虫培养上清呈时间剂量依赖性抑制A549细胞系增殖,处理组细胞周期在G2/M期产生阻滞;A549细胞系的cyclinB1、cdc2蛋白表达量下降。结论刚地弓形虫培养上清能够抑制肺癌A549细胞系增殖,并通过调节cyclinB1、cdc2等蛋白表达或活性改变引起肺癌A549细胞系G2/M期阻滞。

Objective To investigate whether there is an inhibition of the human lung cancer cell line A549 induced by the culture supernatant of Toxoplasma gondii in vitro and the mechanism of the inhibition. Methods A549 cells 5 × 10^4mL^-1 were cultured and harvested. The cells were treated for different hours with different concentrations of Toxoplasma gondii culture supernatant （the concentrations of tachyzoites were 4 ×10^7mL^-1, 8 × 10^7mL^-1 ,16 × 10^7mL^-1 respectively）. Growth inhibition rate was measured with the MTT method;Cell cycle was checked with flow cytometer. Western blot was used to detect the level of cyclinB1 and ode2 of cells. Results The culture supernatants of Toxoplasma gondii inhibited proliferation of A549 cells in a time-dose dependent manner. Cell cycle was significantly stopped at G2/M phase by the culture supernatants with FCM technology. The culture supernatant of Toxoplasma gondii reduced the expressions of gene cyclinB1 and ode2 of A549 cells. Conclusion The culture supernatant of Toxoplasma gondii may inhibit A549 cell and arrest the cell cycle of A549 cells mainly by regulating the expression of gene cyclinB1 and cdc2.