Objective: To investigate the role of HPV16E6 and E7 during the transformation of oral epithelial cells.
Methods: An human immortalized oral epithelial cell line (HIOEC) was established by transfecting HPV16E6, E7 open reading frames using recombinant retroviral system plxsn to human normal oral epithelial cells. Expression of HPV16E6, E7, Rb, P16 and Cycin D1 were analyzed by Western blot in HIOEC and human normal oral epithelial cells. Formation of complex of HPV16E7 and Rb were analyzed by Immunoprecipitation-western blot. Human normal oral epithelial cells and the oral epithelial cells transfected with plxsn were used as control groups.
Results: HIOEC expressed HPV16 E6 and E7; HIOEC expressed both hyperphosphorylated and underphosphorylated Rb while oral epithelial cells in two control groups only expressed hyperphosphorylated Rb. HPV16 E7 formed complex with underphosphorylated Rb; the level of P16 and Cyclin D1 had no remarkable change.
Conclusions: HPV16E7 plays an important role in the immortalization of oral epithelial cells induced by HPV16.