Activation of c-Myc contributes to bovine papillomavirus type 1 E7-induced cell proliferation.

摘要: Inactivation of the tumor suppressor pRB by human papillomavirus (HPV) oncoprotein E7 is a mechanism which HPV promotes cell growth. The bovine type 1 (BPV-1) does not bind efficiently yet required for full transformation murine cells BPV-1. In present study, we investigated BPV-1 E7-induced proliferation. Our studies indicate that expression induces DNA synthesis and stimulates to enter S phase in quiescent cells. induction proliferation can occur retinoblastoma gene (Rb)-null cells, suggesting an Rb-independent mechanism. Consistent with this observation, activate transcription E2F family factors (E2F)-responsive promoters. Notably, c-Myc able induce through Rb/E2F-independent pathway. Significantly, levels are increased E7-expressing Moreover, dominant negative mutant inhibited synthesis. notion could down-regulate p27 Cdk2, level decreased while both cyclin A E-associated kinase activities up-regulated These important role