The Effect Of Radiotherapy Sensitization Of Grape Seed Procyanidin Extract On Lung Adenocarcinoma Cells SPC-A-1

Objective:To study the enhancement radiosensition of grape seed procyanidin extract for X-ray radiotherapy on lung cancer cell line SPC-A-1 in vitro and try to explore its mechanism.Methods:1.The enhancement of radiosensitising effect was detected by clone formation experiment and MTT methods. The radiosensitising dose of anthocyanidin was determined by single-factor analysis of variance. The ratio of sensitization and relevant parameters were calculated by the multi-target/single-hit model.2.Flow cytometry (FCM)was used to measure cell cycle and apoptosis in radiotherapy group and increasing radiatesensitivity group.3.Compared with control group, the expression of CyclinDl mRNA of a variety of concentration of the radiosensitising group analyzed by FPCR.Results:1.The results of MTT indicated that the inhibition effect on SPC-A-1 was slight when only using procyanidin, and the IC50 greater than 400 ug/ml. Though, after the lung cancer cell line was administrated by procyanidin, the sensitivity of X-ray radiotherapy was enhanced. The study showed that the procyanidin and X-ray has synergistic effects, the dose of 100 ug/ml has the significant sensitizing effect, and the ratio of sensitization was 2.56.2.Flow cytometry analysis showed that procyanidin induced apoptosis of SPC-A-1 cells (The apoptotic rate were 28.4%,14.9%,5.3%, respectively.)and inhibited the proceeding of cell cycle in Gl period.3.PCR showed that the CyclinD1 protein expression were down-regulated by administration of procyanidin.Conclusion:Grape seed procyanidin extract has the significant sensitizing effect on radiotherapy in lung adenocarcinoma cells SPC-A-1. GSEP inhibits the proliferation of malignant human Lung adenocarcinoma cancer cells and induces their apoptosis. Expression of CyclinD1 protein may be related to cell growth inhibition and the apoptosis mediated by GSEP in vitro.