Effects of vitamin E succinate on the expression of Fas and PCNA proteins in human gastric carcinoma cells and its clinical significance

AIM: To investigate the effects of vitamin E succinate (VES) on the expression of Fas and PCNA proteins as well as its clinical significance in human gastric carcinoma, and to explore the mechanism of VES-induced inhibition of gastric carcinoma cell growth. METHODS: Immunohistochemical methods were used to detect Fas and PCNA expression both in human gastric cancer SGC-7901 cells treated with VES at different doses and in human gastric carcinoma tissues. RESULTS: After the SGC-7901 cells were treated with VES at 5, 10, 20 mg/L for 48 h, the positive rates of Fas expression were 16%, 27% and 48%, respectively, significantly increased compared to that of control group (P<0.05); while the positive rates of PCNA expression in groups treated with different doses of VES were 20%, 18% and 7%, respectively, which were significantly decreased compared to that of the control group (P<0.05). In human gastric carcinoma tissues, the Fas positive expression rate was 42.4%(25/59), which declined with the decrease in the degree of tumor differentiation (P<0.05) and with the existence of lymph node metastasis (P<0.001). While the PCNA positive expression rate was 91.5%(54/59), no relationship was observed between PCNA expression and clinicopathologic parameters. CONCLUSION: VES inhibited the growth of gastric cancer cells by indudng Fas expression and inhibiting PCNA expression. It is, therefore, considered that the expression of Fas and PCNA genes, through tumor cell apoptosis and proliferation, respectively, may be useful as a clinical predictive index in the application of VES to gastric carcinoma therapy, where as Pas may be of more value than PCNA.

Effect of vitamin E succinate on the proliferation of human breast cancer cells

Objective：Tn investigate the growth inhibition and apoptosis induced by vitamin E suceinate （VES） on human breast cancer cells and to analyze the possible mechanism in this process. Methods： Human breast cancer cell line Bcap-37 was treated with VES for 12, 24 and 48 h at the concentrations of 5, 10and 20 μg/ml. Then MTT assay was employed to detect the inhibitory effect of VES on the growth of breast cancer cells. Flow cytometry was used to analyze the cell cycle and apoptosis. To find out whether the Fas/FasL pathway was involved in this process, RT-PCR and flow cytometry assay were used to detect the Fas expression at the mRNA and protein level. Results： VESexhibited a significant inhibitory effect on the growth of human breast cancer cells, presenting in a dose- and time-dependant manner. The apoptotic rate of Bcap 37 cells was 0.6%, rose to 21.0% and 37.5% after treated with VES for 24 and 48 h at the concentration of 20 μg/ml. Fas mRNA transcription was upregulated after VES treatment and cell surface Fas expression increased according to the flow cytometry assay. Concluslon：Significant growth inhibition and apoptosis are induced in human breast cancer cells after treated with VES. The modulation of Fas/FasL pathway may related to the upregulation of Fas molecule on the cancer cell surface.