Study Of Indicative Effect On Tumor Therapy By Detecting γh2ax

Purpose:By way of examining the expression of yH2AX, we could know the sensitivity information of tumor cells on radiotherapy and chemotherapy so as to find an economical, simple and rapid method to monitor the tumor therapy.Methods:1. Methods to treat tumor cells1.1 X-rays:HepG2.215 cells were exposed to X-rays of different doses respectively. Then phosphorylated histoneγH2AX and cell viability were examined. 1.2 chemotherapeutical drugs:HepG2.215 cells were exposed to etoposide, doxorubicin, mitomycin or cisplatin of different concentrations respectively.Then phosphorylated histone yH2AX and cell viability were examined.2. Detection of yH2AX foci using immunocytochemistryyH2AX foci were detected using the immunocytochemistry method of strepto-avidin-biotin-peroxidase complex(SP).3. Detection of the fraction of cells positive for yH2AX using flow cytometryThe fraction of cells positive for yH2AX was detected using indirect fluorescence staining and labeling.4. MTT assay for cell viabilityCell viability was measured using MTT assay on cells taken from the same population that were analyzed for yH2AX.Results:1. After HepG2.215 cells were exposed to X-rays, the expression of yH2AX was dose-dependent and increased linearly with dose; The level of yH2AX was positively correlated with cell mortality. The more the expression of yH2AX was, the higher cell mortality was.2. After HepG2.215 cells were exposed to chemotherapeutical drugs, yH2AX levels increased with drug concentration(or dose) in all experimental groups for the same drug; There was a positive correlation between yH2AX formation and cell mortality, with more yH2AX and higher cell mortality.3. The relative amount of yH2AX was also positively correlated with cell mortality. The more the relative amount of yH2AX was, the higher cell mortality was.Conclusions:There was a positive correlation between the expression of yH2AX and cell mortality. The expression of yH2AX could provide some information for tumor cells in sensitivity to radiotherapy and chemotherapeutics. Detection of yH2AX was significant in directing·tumor therapy.