Effect of the transfer and expression of p27 gene on the proliferation of rat vascular smooth muscle cells mediated by recombinant adenovirus vector

Objective To investigate the effect of transfering and expression of p27 gene on cultured vascular smooth muscle cells(VSMCs) in rats and explore its mechanism.Methods Recombinant adenoviral vector,AdCMV-p27,containing human p27 gene was constructed by site special recombination,and it was used to transfer p27 gene into rat VSMCs.The ratio of p27 expression in VSMCs was analyzed by flow cytometry system(FCS).The protein expressions of p27,proliferating cell nuclear antigen(PCNA),cyclin-dependent kinase2(CDK2) and connexin43 were detected by immunocytochemistry method 24h after the PDGF-BB or Serum added.The cell cycle and DNA synthesis of the VSMCs were used to determine the proliferation of VSMCs by FCS and thymidine incorporation,respectively.Results The expression ratio of p27 in VSMCs was significantly increasing after transfected by AdCMV-p27 with the time,and the peak value was about 85.81% at 24th hour.The ratio of G0~G1 phase and thymidine incorporation stimulated by mitogen was significantly increased and decreased in transfected cells compared with non-transfected cells,respectively(P0.05).Compared with the PDGF-BB stimulated group,the positive expressions of p27 protein in transfected cells were not only significantly increased from 4.23% to 33.91%,but also that of CDK2,PCNA and connexin43 induced by PDGF-BB were remarkably decreased(P0.01).Conclusion The overexpression of p27 mediated by AdCMV-p27 can significantly inhibit the proliferation of rat VSMCs induced by mitogen,which is relate with the enhanced expression of p27 protein and decreased protein expression of CDK2,PCNA and Cx43.