RESUMO
Objective To investigate the effect of El A gene on the radiosensitivity of human laryngeal carcinoma cells and its correlated mechanisms. Methods The Ad-E1A and Ad-β-gal were amplifieated in Hek293 cells, extracted by freezing (-80℃) and thawing(37℃) repeatedly (3 times) , purificated by the method of density gradient of CsC1 and titrated by plaque assay method. Then they were transfected into human laryngeal carcinoma cells (Hep-2) and authenticated by RT-PCR. The radiosensitivity of Hep-2 cells transfeeted with or without El A were studied by cell surviral curve. Finally we investigated the correlated mechanisms including cell apoptosis studied by flow cytometry and VEGF content studied by RT-PCR. Resuits The radiosensitivity of Hep-2 cells transfected with El A was intensified, Do and Dq were lowered and α was increased. Flow cytometry showed that the apoptosis rate of cells with E1A or with El A and radiotherapy was increased. The VEGF content of the cells transfeeted with E1 A or treated by radiotherapy was decreased, which reached the lowest level when the cells were treated with the both mathods. Conclusions E1 A gene can intensify the radiosensitivity and contribute to the apoptosis of human laryngeal carcinoma cells. El A gene and radiotherapy can markedly decrease the VEGF content.