Effect Of E1A Gene On Growth And Radiosensitivity Of Hep-2 Cells Of Human Laryngeal Carcinoma And Correlated Mechanism Of Action

OBJECTIVE:To investigate the effects of E1A gene on the growthes,multiplications and radiosensitivities of human laryngeal carcinoma and the correlated mechanism of action.METHODS:The Ad-E1A and Ad-β-gal amplificated in Hek293 cells,extracted by freezing and thawing repeatedly(3times),purificated by the method of density gradient of CsC1 and titrated by plaque assay method.Then transfect them to Hep-2 cells and authenticate by RT-PCR and filtrated by G418..The growth rate in vitro of human laryngeal carcinoma cells transfected and untransfected with E1A were studied by cellur count and MTT and the cell cycle was analyzed by flow cytometry. The radiosensitivity of human laryngeal carcinoma cells transfected and untransfected with E1A were studied by cell survival curve which protracted by clonogenic assay and caculating Do,Dq,α,β;Finally we investigated the correlated mechanism throw the cell apoptosis which studied by flow cytometry and the VEGF content which studied by RT-PCR.RESULTS:The growth rate in vitro of human laryngeal carcinoma transfected with E1A was suppressed,the doubling time was prolonged and the cell cycle was changed that the S Phase was reduced and the G₂/M phase was blocked;The radiosensitivity of human laryngeal carcinoma transfected with E1A was intensified and the D₀ was lowered;The results of flow cytometry show that the cell apoptosis rate with E1A and with E1A and radiotherapy were increased;The VEGF content of human laryngeal carcinoma transfected with E1A and after radiotherapy respectively was decreased,but it was decreased most which transfected with E1A and after together.CONCLUSIONS:E1A gene could suppress the growth in vitro, could prolong the doubling time and could change the cell cycle of human laryngeal carcinoma cells;E1A gene could intensify the radiosensitivity of human laryngeal carcinoma cell;E1A gene and radiotherapy could decrease the VEGF content of human laryngeal carcinoma cell;E1A gene could contribute to the apoptosis of human laryngeal carcinoma cell.