Effect Of Up-Regulation The Transcription Factor Gli1of Sonic Hedgehog Pathways On The Radioresistance Of Esophageal Cancer

AIM: To investigate the potential role of Sonic Hedgehog(Shh)pathway and the effect of up-regulation the transcription factor Gli1 of Sonic Hedgehog pathways on the radioresistance of esophageal cancer.METHODS: 1.Radioresistant cell line Eca109 R was established by repeating X-ray irradiation at dose of 60 Gy in total using Eca109 cells as parental cells.2.The radiosensitivity of the parental and radioresistant cells were confirmed by colony formation assay.3.The cell activity was detected by CCK8 assay.4.The intracellular protein levels of Shh and Glil were determined by Western blotting and immunofluorescence,respectively.5.Eca109 cell was transfected with plasmid which over express Gli1 gene,then detected the intracellular levels of Shh and Glil by Realtime-PCR and Western blotting.6.The radiosensitivity of the transfected and the untransfected cells were confirmed by colony formation assay.7.The cell cycle phase of the transfected and the untransfected cells were analysised by flow cytometry.RESULTS: 1.The survival fraction at dose of 2 Gy for Eca109 R cells and Eca109 cells were 0.937±0.013 and 0.499±0.042,respectively,suggesting that the radioresistant cell line was successfully established.2.The inhibitory rate of cell activity decreased gradually in the Eca109 R cells(p<0.05).3.The results of Western blotting indicated that the protein expression of Shh and Gli1 was much higher in the Eca109 R cells than that in the Eca109 cells(p<0.05).Immunofluorescence staining showed that the protein expression of Gli1 was much higher in the Eca109 R cells than that in the Eca109 cells(p<0.05).4.The results of Realtime-PCR and Western blotting indicated that the expression of Shh and Gli1 was much higher in the transfected than that in the untransfected cells(p<0.05).5.The colony formation assay indicated that the radioresistance of the transfected cells was stronger than that of the untransfected cells.6.After irradiation at dose of 6 Gy and 8 Gy,the cell cycle arrest in the G2/M phase was found in the transfected and untransfected cells,compared with the untransfected cells,the transfected cells showed higher s phase fractions.CONCLUSION: Up-regulation the transcription factor Gli1 of Sonic Hedgehog Pathways enhance the radioresistance of esophageal cancer,this process can be achieved by regulating the cell cycle.