Combination of calcineurin B subunit (CnB) and 5-fluorouracil reverses 5-fluorouracil-induced immunosuppressive effect and enhances the antitumor activity in hepatocellular carcinoma

Characterization of calcineurin A and B genes in the abalone, Haliotis diversicolor, and their immune response role during bacterial infection

Calcineurin (CN) is known to be involved in many biological processes, particularly, the immune response mechanism in many invertebrates. In this study, we characterized both HcCNA and HcCNB genes in Haliotis diversicolor, documented their expression in many tissues, and discerned their function as immune responsive genes against Vibrio parahaemolyticus infection. Similar to other mollusk CNs, the HcCNA gene lacked a proline-rich domain and comprised only one isoform of its catalytic unit, in contrast to CNs found in mammals. HcCNB was highly conserved in both sequence and domain architecture. Quantitative PCR and in situ hybridization revealed that the genes were broadly expressed and were not restricted to tissues traditionally associated with immune function. Upon infection of H. diversicolor with V. parahaemolyticus (a bacteria that causes serious disease in crustaceans and mollusks), both HcCNA and HcCNB genes were highly up-regulated at the early phase of bacterial infection. HcCNB was expressed significantly higher than HcCNA in response to bacterial challenge, suggesting its independent or more rapid response to bacterial infection. Together, the two CN genes are unique in their gene structure (particular HcCNA) and distribution in mollusk species and likely function as immune responsive genes along with many other genes that are enhanced in the early phase of V. parahaemolyticus infection in abalone.

Cordycepin suppresses the migration and invasion of human liver cancer cells by downregulating the expression of CXCR4

Liver cancer is a worldwide threat to human health. High expression levels of C-X-C chemokine receptor type 4 (CXCR4) have been reported to promote the migration and invasion capacities of liver cancer cells. Cordycepin, extracted from Cordyceps militaris, has anti-inflammatory, antioxidant and anticancerous properties. Therefore, in the present study, migration assays, western blotting, reverse transcription-quantitative PCR and immunofluorescence analyses were conducted to determine whether cordycepin was able to suppress the migration and invasion abilities of liver cancer cells by inhibiting CXCR4 expression. The results suggested that cordycepin notably inhibited migration and invasion, and decreased the expression of CXCR4 in a dose-dependent manner. Activation of phosphorylated (p-) NF-κB inhibitor α (IκBα) and p-P65, the principal components of the NF-κB signaling pathway, was also downregulated. In addition, cordycepin markedly suppressed the nuclear translocation of P65, but had no effect on the expression of total IκBα (t-IκBα) and total P65 (t-P65). JSH-23, an inhibitor of the NF-κB pathway, impaired the migration of liver cancer cells, and was found to act synergistically with cordycepin. Furthermore, cordycepin treatment reduced the chemotactic migration ability of liver cancer cells to stromal cell-derived factor 1 (SDF1), which was significantly enhanced following treatment with JSH-23. Collectively, the present results indicated that cordycepin inhibited the nuclear translocation of P65 by preventing p-IκBα activation; this resulted in the downregulation of CXCR4 expression, and subsequently, in the impaired migration and invasion abilities of liver cancer cells and attenuated reactivity to SDF1. The current study revealed a novel mechanism for the antimetastatic activity of cordycepin and its potential to exert positive synergistic effects with other compounds for the treatment of liver cancer.