RESUMEN
OBJECTIVE:To study the antitumor effect of phellinus linteus polysaccharide on sarcoma S180 cells in vivo and in vitro. METHODS:Sarcoma S180 cells in logarithmic growth period were selected,adding into 0(blank control),2,4,8 mg/mL phellinus linteus polysaccharide solution and respectively culturing for 12,24,36,48 h. The in vitro proliferation inhibition rate of cells was determined by MTT method;its apoptotic morphology was observed by fluorescence staining and cell apoptosis rate was detected by flow cytometry. S180 tumor-bearing mice models were established and randomly divided into control group,phellinus linteus polysaccharide high-dose,medium-dose,low-dose groups(400,200,100 mg/kg),10 in each group. Model mice were in-tragastrically administrated related medicined,once a day,for 12 d. Mice were executed after 24 h of last administration,tumor weight was determined,tumor inhibition rate was calculated. Immunohistochemistry was conducted to detect the tumor suppressor gene PTEN and oncogene C-myc protein expressions in tumor tissue. RESULTS:Compared with blank control group,phellinus linteus polysaccharide can increase the proliferation inhibition rate of S180 cells and induce the increase of apoptosis rate(P<0.05 or P<0.01),showing a concentration-time manner. Compared with control group,the tumor inhibition rates in phellinus linteus polysaccharide groups were obviously increased (P<0.01),PTEN protein expressions were strengthened (P<0.05 or P<0.01) and C-myc protein expressions were weakened (P<0.05). CONCLUSIONS:Phellinus linteus polysaccharide shows antitumor ef-fect in vivo and in vitro,which can up-regulate the PTEN,down-regulate C-myc protein expressions.