Enterovirus 71 modulates a COX-2/PGE2/cAMP-dependent viral replication in human neuroblastoma cells: Role of the c-Src/EGFR/p42/p44 MAPK/CREB signaling pathway

Enterovirus 71 (EV71) has been shown to induce cyclooxygenase-2 (COX-2) expression in human neuroblastoma SK-N-SH cells through the action of MAPKs, NF-KB, and AP-1. On the other hand, the transcription factor CREB has also been implicated in the expression of COX-2 in other cell lines. Here, we report that EV71-induced COX-2 expression and PGE₂ production were both inhibited by pretreatment with the PKA inhibitor H89 or by transfection with CREB siRNA. In addition, EV71-induced COX-2 expression and c-Src/EGFR phosphorylation were both attenuated by transfection with c-Src siRNA or pretreatment with the inhibitors of c-Src (PP1) or EGF receptor (EGFR) (AG1478 and EGFR-neutralizing antibody). We also observed that EV71-induced p42/p44 MAPK phosphorylation was decreased following pretreatment with AG1478. Moreover, EV71-induced COX-2 expression was blocked by pretreatment with the p300 inhibitor GR343 or by transfection with p300 siRNA. Using immunoprecipitation and chromatin immunoprecipitation assays, we observed that EV71 stimulated the association of CREB and p300 with the COX-2 promoter region. Notably, we also demonstrated that EV71-induced COX-2 expression and PGE₂ production promoted viral replication via cAMP signaling. In summary, this study demonstrates that EV71 activates the c-Src/EGFR/p42/p44 MAPK pathway in human SK-N-SH cell, which leads to the activation of CREB/p300, and stimulates COX-2 expression and PGE ₂ release.