Ganoderma Polysaccharides On The Mgc-803 Cell Proliferation Inhibitory Effect Of Pka Ptk Activity

Objective :To observe the effects of polysaccharide extracted from Ganoderma applanatum (GAPS) on cell proliferation , cell cycle different phase distribution, activity of PKA and PTK of human gastric cancer cell line MGC-803 . To explore its potential mechanisms of anti-tumor of GAPS at molecular level.Methods :MTT assay was used to investigate the inhibitory effect of GAPS on MGC-803 . Cell cycle and phosphorylation of PTK, EGFR and PDGFR-βwere analyzed by flow cytometry (FCW). The activity of PKA was detected by non-radioactivity assay. The fluorescence intensity of expression of EGFR and PDGFR-βin MGC-803 cells were observed by fluorescence microscope.Results :GAPS inhibited the proliferation of MGC-803 cells in dose-dependent and time-dependent manners. After MGC-803 cells were treated with 2 mg/ml GAPS for 72 h , cell cycle were arrested at G0/G1 phase with statistic significance of difference compared with the blank control group (p<0.05) . PKA activity was increased of statistic significance in the GAPS group compared with the blank control group, (p<0.05). The phosphorylation of PTK of the treated group was decreased with statistic of difference compared with the blank control group (p<0.05). The results by Flow cytometry showed that positive percentage of the expression of EGFR and DGFR-βin GAPS group were decreased compared with the control group with statistically significant of the difference(p<0.05). The fluorescence intensity of expression of EGFR and PDGFR-βin GAPS treated group cells were weakened, which consistent with the results of FCW.Conclusion : GAPS can inhibit proliferation of gastric cancer MGC-803 cell lines and the mechanism of its role of anti-tumor as followings :(1)GAPS can prevent cell cycle from stepping down the proceeding, arresting at G0/G1 phase ;(2)GAPS can increase the activity of PKA so that it regulared the proliferation of MGC-803 cells by exerting on the negative regulation of cell proliferation signal transduction pathway;(3)GAPS can decrease the phosphorylation of PTK and the expression of EGFR and PDGFR-βwhich are receptor tyrosine kinases.