Expression of RMP gene on apoptosis of human hepatoma cells induced by γ-rays

Objective: To explore the effect of RPB5-Mediating Protein (RMP) on apoptosis of human hepatoma cell line SMMC-7721 induced by being exposed to 60Co γ-rays of different doses and its possible role in cell DNA stability and apoptosis. Methods: The SMMC-7721 cells and human hepatic cell HL-7702 were exposed to 60Co γ-rays of different doses. Apoptosis was observed by PI staining. Flow cytometric technique was used to detect apoptosis and cell cycle. Semiquantitative RTPCR assay was used to detect the expression of RMP, bax and bcl-2 gene. Results With the exposure doses increasing, the morphous of the cells changed obviously. Apoptosis increased observed by PI staining. The results of flow cytometry showed the cell apoptosis increased obviously with the exposure doses increasing (P<0.05), cell cycle showed that G1 stage raisde up while S stage cut down (P<0.05). The expression of RMP and relative value of bax/bcl-2 increased (P <0.05). Conclusion: Radiation exposure can induce human hepatoma cells' apoptosis and RMP gene may play an important role in cell DNA stability. (authors)