Apoptosis of Hep-2 cells induced by high energy X-ray and expression of apoptosis-related genes

Objective: To study the effect of high energy X-ray on the apoptosis of human laryngeal cancer cell line Hep-2 and the possible mechanism.Methods: Hep-2 cells were exposed to different doses of high energy X-ray and then cultured for various times.The apoptosis rate of Hep-2 cells was determined by flow cytometry.The expressions of BCL-2 and BAX protein and mRNA in Hep-2 cells were deter-mined by Western blot and reverse transcriptase polymerase chain reaction,respectively.Results: The apoptosis rate of Hep-2 cells increased with the prolongation of culture time and the increment of radiation dose.The expressions of BCL-2 protein and mRNA decreased after Hep-2 cells exposed to high energy X-ray,but no change in the expressions of BAX protein and mRNA was found.The ratio of BCL-2 to BAX decreased.Conclusion: The high energy X-ray induces the apoptosis of Hep-2 cells in a dose-and time-dependent manner.BCL-2 could inhibit the apoptosis of Hep-2 cells induced by radiation,which may be involved in the malignant proliferation of Hep-2 cells.