OBJECTIVE: To study the inhibition of human gastric cancer cell line BGC-823 by exopolysaccharide (B. EPS) extracted from Bifidobacterium bifidum and the effect on the activity of telomerase rate-limiting factor human telomerase reverse transcriptase (hTERT). METHODS: In vitro human gastric cancer cell line BGC-823 were treated by three concentrations of B. EPS. The inhibition rate of gastric cancer cell line BGC-823, the morphology changes of cells and the apoptosis in the initial stage of cell was observed respectively by MTF, inverted fluorescent microscope and the Annexin V-FITC/PI flow cytometry. In addition, the effect of B. EPS on cell telomerase rate-limiting factor hTERT mRNA was tested by RT-PCR; the changes in the concentration of calcium ions inside the cytoplasm were detected by spectrofluorometer. RESULTS: B. EPS inhibited the growth of gastric cancer cell BGC-823 (P < 0.05), the inhibition rate increased and the concentration of B.EPS showed dose-time response relation. The expression of cell telomerase rate-limiting factor hTERT mRNA decrease after effected by B.EPS (P < 0.05), and showed dose-effect relation with B. EPS. The concentration of calcium ion in cytoplasm was higher than the control apparently (P < 0.05). CONCLUSION: The apoptosis mechanism of human gastric cancer cell line BGC-823 induced by B. EPS might be relevant with the changes of the hTERT mRNA expression and the calcium ions concentration in cytoplasm.
OBJECTIVE: To study the inhibition of humangastric cancer cell line BGC-823 by exopolysaccharide (B. EPS) extracted from Bifidobacterium bifidum and the effect on the activity of telomerase rate-limiting factor human telomerase reverse transcriptase (hTERT). METHODS: In vitro humangastric cancer cell line BGC-823 were treated by three concentrations of B. EPS. The inhibition rate of gastric cancer cell line BGC-823, the morphology changes of cells and the apoptosis in the initial stage of cell was observed respectively by MTF, inverted fluorescent microscope and the Annexin V-FITC/PI flow cytometry. In addition, the effect of B. EPS on cell telomerase rate-limiting factor hTERT mRNA was tested by RT-PCR; the changes in the concentration of calcium ions inside the cytoplasm were detected by spectrofluorometer. RESULTS: B. EPS inhibited the growth of gastric cancer cell BGC-823 (P < 0.05), the inhibition rate increased and the concentration of B.EPS showed dose-time response relation. The expression of cell telomerase rate-limiting factor hTERT mRNA decrease after effected by B.EPS (P < 0.05), and showed dose-effect relation with B. EPS. The concentration of calcium ion in cytoplasm was higher than the control apparently (P < 0.05). CONCLUSION: The apoptosis mechanism of humangastric cancer cell line BGC-823 induced by B. EPS might be relevant with the changes of the hTERT mRNA expression and the calcium ions concentration in cytoplasm.