The Radiosensitization Effects And Its Mechanisms Of Recombinant Human Endostatin On Human Esophageal Carcinoma Cell KYSE-150

Objective:This study was to investigate the effect of Recombinant Human Endostatin (rhES), a targeted therapy drug by inhibiting pathological angiogenesis of tumor and inhibiting proliferation and metastasis of tumor cells, on human esophageal carcinoma cell KYSE-150radiosensitivity. The thesis contained:the drug’s influence on the proliferation of human esophageal carcinoma cell KYSE-150and expression level of VEGF、HIF-1after the cells treated by X irradiation. The data showed a primary investigation of rhES’s radio sensitizing mechanism.Methods:1. The effect of rhES on the survival fraction of human esophageal carcinoma cell KYSE-150and fibroblast L929(control cell) was investigated with the method of MTT.2. Crocolony formation assay was used to determine the radiosensitivity of KYSE-150cells and L929cells and rhES’s radiation-enhancing effect.3. Influence of rhES on VEGF、HIF-1’s expression level of KYSE-150cells and L929cells was investigated by Western Blot. Results:1. KYSE-150’s cell proliferation inhibition effect of rhES presented a concentration-dependent and time-dependent manner, and the inhibition effect increased as the concentration increased and the time delayed. There were no significant difference in L929’s cell proliferation inhibition effect of rhES.2. Under the same radiation dose,Colony formation rate decreased as the rhES concentration increase, while Colony formation rate decreases as the irradiation dose increase under the same rhES concentration. There was an interaction effect between rhES and irradiation. The dose enhancement ratio (DER) increased as the rhES concentration increased when the survival rate was50%. the radiobiological parameter D0、Dq and SF2decreased with the elevation of the rhES concentration. The sensiti-zing enhancement ratio (SER) of rhES(200μg/ml) was1.28,when irradiation dose was at DO. To the L929cell line, The values of D0、Dq、and SF2and the SER of rhES have slight downward trend only but this was not statistically significant.3. VEGF level of human esophageal carcinoma cell KYSE-150were slightly increased after X-irradiation,while HIF-1level decreased; VEGF、HIF-1level of human esophageal carcinoma cell KYSE-150were decreased slightly after dealing with rhES; Compared with X irradiation alone group or rhES alone, VEGF、HIF-1level of human esophageal carcinoma cell KYSE-150were decreased significantly after combinating X-irradiation with rhES. To L929cell line, VEGF、HIF-1protein of human esophageal carcinoma cell KYSE-150were not found in our Western Blot experimentation after X-irradiation alone、dealing with rhES alone and combination group.Conclusions:1. RhES inhibits the growth of human esophageal cancer cells KYSE-150obviously,in time concentration and time dependent manner.2. RhES had the radio-sensitizing effect on KYSE-150cells after they irradiated by X ray and the best effect would be obtained when the rhES concentration was200μmol/l.3. VEGF、HIF-1level of human esophageal carcinoma cell KYSE-150were decreased when treated with rhES group; Compared with X irradiation alone group, VEGF、HIF-1level of human esophageal carcinoma cell KYSE-150decreased significantly in the combination group. This effect may be associated with the down-regulation of VEGF and HIF-1expression.