Cordycepin Suppresses Integrin/FAK Signaling and Epithelial-Mesenchymal Transition in Hepatocellular Carcinoma

Cordycepin, also known as 3-deoxyadenosine, is an analogue of adenosine extracted from the traditional Chinese medicine Dong Chong Xia Cao. Cordycepin is an active small molecular weight compound and is implicated in modulating multiple physiological functions including immune activation, anti-aging and anti-tumor effects. Several studies have indicated that cordycepin suppresses tumor progression. However, the signaling pathways involved in cordycepin regulating cancer cell motility, invasiveness and epithelial-mesenchymal transition (EMT) remain unclear. In this study, we found that cordycepin inhibits hepatocellular carcinoma (HCC) cell proliferation and migration/invasion. Treatment of cordycepin results in the increasing expression of epithelial marker, E-cadherin while no significant effect was found on N-cadherin, alpha-catenin and beta-catenin. Furthermore, although the expression of focal adhesion kinase (FAK) was slightly reduced, the level of phosphorylated FAK was significantly reduced by the treatment of cordycepin. In addition, cordycepin significantly suppresses the expression of integrin alpha 3, integrin alpha 6 and integrin beta 1 which are crucial interacting partners of FAK in regulating the focal adhesion complex. These results suggest cordycepin may contribute to EMT, anti-migration/invasion and growth inhibitory effects of HCC by suppressing E-cadherin and integrin/FAK signaling. Thus, cordycepin is a potential therapeutic or supplementary agent for preventing HCC tumor progression.