天花粉蛋白诱导胃癌细胞MKN-45凋亡中P53、Bcl-2、c-myc蛋白表达变化

Changes of expressing P53、Bcl-2、c-myc in induction of apoptosis by trichosanthin in gastric cancer cell MKN-45

目的 选用对天花粉蛋白敏感的胃癌细胞株MKN 45 ,研究天花粉蛋白抗肿瘤机制。方法 免疫组化法测定凋亡相关基因 (P5 3、Bcl 2、c myc)的表达变化。 结果 胃癌细胞MKN 45经天花粉蛋白 (1μg/ml,2 4、48h)处理后 ,凋亡相关基因P5 3、Bcl 2、c myc表达未出现显著性改变。经 5 μg/ml的天花粉蛋白处理 2 4h后 ,得到相同结论。但当MKN 45细胞经 5 μg/ml的天花粉蛋白处理 48h后 ,发现野生型P5 3蛋白表达增加 ,而Bcl 2、c myc蛋白表达未出现显著性改变。 结论 天花粉蛋白可诱导MKN 45细胞凋亡 ,可能与上调野生型P5 3基因的表达有关。

Objective To explore the anti tumour mechanism of actions of trichosanthin (TCS) on TCS sensitive cell line gastric adenocarcinoma cell MKN 45. Methods The levels of protein of tumor apoptosis related genes (p53、Bcl 2、c myc) were determined by using of immunohistochemical method.Results MKN 45 cells were treated by TCS(1 μg/ml, 24 h, 48 h respectively), immunohistochemical staining did not show any significant changes of expression of apoptosis related genes p53,Bcl 2 and c myc. The same results of MKN 45 cells were treated by high concentration of TCS(5 μg/ml, 24 h), were obtained with prolongation of TCS(5 μg/ml, 48 h) treating time, the wild type p53 protein product in MKN 45 increased obviously ( P <0.05) without any changing of the expression of Bcl 2 and c myc protein.Conclusion This induction of apoptosis may be mediated by increase of expressing tumor suppressor gene p53(wild type). TCS might have a promising role in the treatment of gastric cancer.