RESUMO
SATB1 plays a crucial role in the invasion and metastasis of breast cancer,and inhibition of SATB1 expression can effectively control breast cancer metastasis. In this study,homogeneous polysaccharides were isolated from Poria cocos and their sulfated derivatives were prepared to screen out the polysaccharide compositions with inhibitory effects on SATB1 expression. Smal-molecule components were removed from P. cocos by ethanol extraction,and P. cocos crude polysaccharide PPS was obtained by water extraction and ethanol precipitation. Then PPS was successively separated by DEAE Sepharose fast flow anion-exchange and Superdex-75 gel permeation chromatographic steps to give PPSW-1. The structure of PPSW-1 was identified and its sulfated derivatives were prepared. Then their inhibitory effects on human breast cancer MDA-MB-231 cells were investigated. A kind of polysaccharide,PPSW-1 with inhibitory effect on human breast cancer MDA-MB-231 cells,was obtained from P. cocos,with a relative molecular weight of 3. 06×104,and structure of 1,6-branched 1,3-α-D-galactan. PPSW-1 and its sulfated derivative Sul-W-1 showed good inhibitory effect on cells migration,and the water solubility of Sul-W-1 was better than that of PPSW-1. In addition,it was found that polysaccharide of P. cocos and its sulfated derivative can inhibit expression of SATB1. In this study,a kind of homogeneous polysaccharide with inhibitory effect on human breast cancer MDA-MB-231 cells was isolated from P. cocos,and its sulfated derivative with similar efficacy but better solubility was prepared,laying the foundation for the substance basis study of P. cocos.