Induced apoptotic action of recombinant trichosanthin in human stomach adenocarcinoma MCG803 cells.

Trichosanthin (TCS), is purified from the Chinese medicine, exerts antitumor activities by inducing apoptosis in many different tumor cell lines. The cDNA of trichosanthin was cloned and TCS was purified. The results showed that the proliferation of MCG803 cells were significantly suppressed by TCS in a dose-dependent manner at the concentration ranging from 20 to 100 microg/ml. The result of sequencing analysis indicates we obtained the TCS whole length gene. MTT assay was adopted to measure the growth inhibition ratio of MCG803 cells treated with TCS and apoptosis was assayed by agarose gel electrophoresis. DNA agarose gel electrophoresis showed a gradient, which confirmed that TCS could induce MCG803 cells apoptosis. The proportion of the periodic tumor cells were altered by TCS. Sub-G(1) curves were displayed by flow cytometry analysis. Results of Northern and Western blots showed that the transcription and expression of P21, was gradually up-regulated as treatment time increased. On the contrary, the transcription and expression of p53, was down-regulated. These data provided powerful evidences for the first time that recombinant TCS can induce the apoptosis of the MCG803 cells.