Effect On Expression Of STAT1 And H2AX After Irradiation In Esophageal Carcinoma Cells Lines

Objective: To observe the expression of STAT1 and H2AX mRNA and protein after irradiated in different type of esophageal cancer cells in vitro, in order to test the dose-effects relationship between ionizing radiation intensity and nuclear foci of the STAT1 and H2AX, for providing a base for changing the radio sensitivity of esophageal caicinoma Toad toxinells by gene therapy.Methods: (1) In three human esophageal carcinoma cell lines of TE1, TE13 and Eca109, expression of STAT1 and H2AX mRNA were detected with reverse transcriptase-polymerase chain reaction (RT-PCR), expression of STAT1 and H2AX protein were measured with immunohistochemistry assay, western blotting and indirect immuno-fluorescence assay respectively. (2)Radiosensitivity was analysized with clonegentic assay in TE13 and Eca109 esophageal caicinoma cells in vitro. (3) Expression of STAT1 and H2AX protein were detected with western blotting after irradiated in TE13 and Eca109 esophageal caicinoma cells in vitro. (4) The location and quantity with nuclear foci of STAT1 and H2AX were detected with Zeiss fluorescence microscope.Results: (1)Expression of STAT1 and H2AX in TE1, TE13 and Eca109 cells were observed in level of mRNA and protein, but expression of STAT1 protein were not measured in TE13 and ECA109 with immunohistochemistry assay. (2) D0 value were 2.35Gy and 3.04Gy and SF2 value were 0.752 and 0.796 respectively with clonegenetic assay in TE13 and Eca109 cells, so radiosensitivity is higher in TE13 cells than Eca109 cells. (3)The expression of pSTAT1 protein in TE13 and Eca109 cells were not any changed at 0.5h after irradiated by 0-10Gy, and during 0-24h after irradiated by 4Gy. (4)Level ofγ-H2AX expression was markedly increased at 0.5h after irradiation by 0-10Gy in TE13 and Eca109 cells, and during 0-24h after irradiated by 4Gy. γ-H2AX protein in TE13 and Eca109 cells arrived at peak about 0.5h later, decreased at 1h and recovered to normal level at 24h after radiated by 4Gy. (5) H2AX nuclear foci were clearly present within 5 min after IR. The average number of H2AX-positive foci per cell increased at 0.5h after irradiation by 0-10Gy in TE13 and Eca109 cells, and during 0-24h after irradiated by 4Gy, and peaked 30 min after irradiation. Gradually, the number of H2AX-positive foci decreased to background levels within 24h. The average number of pSTAT1 nuclear foci were not formatted after irradiated, while the pSTAT1 nuclear foci were formatted after treated with cisplatin, but the average number of pSTAT1 nuclear foci was not any changed after irradiation and treated with cisplatin.Conclusion: (1) Expression of STAT1 and H2AX in different type of esophageal carcinoma cells protein were universally existed in level of mRNA and protein. (2) Radiosensitivity is higher in TE13 cells than Eca109 cells. (3) Irradiation can not affect the expression of STAT1 protein and the number of gene H2AX nuclear foci in esophageal cancer cells. the STAT1 nuclear foci was formatted after treated with cisplatin, but no changes of number of nuclear foci with irradiated. (4) The expression of H2AX protein and the number of gene H2AX nuclear foci have dose-effects relationship between ionizing radiation in esophageal cancer cells.