A polysaccharide from Agaricus blazei attenuates tumor cell adhesion via inhibiting E-selectin expression

Agaricus blazei Murill is an edible and medicinal mushroom of Brazilian origin, the components from which have been shown to possess anti-tumor potentials. Meanwhile, E-selectin-mediated cell–cell adhesion plays an important role in extravasation of tumor cells. In this study, the effect of a low molecular weight polysaccharide isolated from A. blazei (LMW-ABP) on the TNF-α-stimulated E-selectin protein and mRNA expression was evaluated in vitro. LMW-ABP could depress the E-selectin protein expression, and similar results were observed for E-selectin gene expression in a dose-dependent manner, which lead to a significant reduction in TNF-α stimulated adhesion of HT-29 cells to HUVEC. These results indicated that the effect of LMW-ABP against tumor cell adhesion was based on the inhibition of E-selectin protein and gene expression. In addition, LMW-ABP also suppressed nuclear factor-kappa B (NF-κB) protein expression and nuclear translocation. The data supported the view that LMW-ABP might be developed to a promising therapeutic agent against E-selectin-mediated neoplasm metastasis.