Molecular Mechanism Of E1A-mediated Radiosensitivity By Interfering With E6/E6AP Interaction

Objective:To investigate the effect of adenovirus E1A gene on radiosensitivity of cervical cancer and the molecular mechanisms.Methods:To transfect pcDNA3.1(+)-E1A plasmid into human cervical cancer cells, using Western Blot to detect the expression of E1A,then the downstream biological behaviors,using flow cytometry to detect the apoptosis induced by E1A in high-risk HPV positive cervical cancer cells;employing immunoprecipitation to explore whether E1A forms complex with E6AP, and in vitro ubiquitination system which reveals the impact of E1A on the ubiquitination level of p53.Results:There is no endogenous E1A expression in cervical cancer cells.ElA can stably expressed in cells through gene thransfection. Western Blot shows that HR-HPV posititive cells displays significantly higher levels of p53when E1A expresses.HPV negative cancer cells have not show the benefit.Flow cytometry showed E1A can significantly increase the radiation sensitivity of cancer cells, which may by way of increasing the expression of p53.Co-immunoprecipitation demonstrates that E1A can form complexes with E6AP,in vitro experiments show that by interfering E6/E6AP complex, E1A reducing the degradation of p53Conclusions:E1A can enhance the apoptosis of cervical cancer induced by radiotherapy,and the possible mechanisms involve the ElA interference E6-E6AP complex, therefore inhibiting the degradation of p53in vivo.