Effect of recombinant human endostatin on the radiosensitivity of esophageal carcinoma cells and underlying mechanism / 中华放射医学与防护杂志

ABSTRACT

Objective To study the effect of recombinant human endostatin (rhES)on the radiosensitivity of esophageal squamous cells KYSE-150 and its preliminary mechanism.Methods Cells were divided into four groupscontrol group without treatment,rhES group treated with recombinant human endostatin,radiation alone group exposed with X-rays,and combination group exposed with X-rays plus endostatin.Colony formation assay was used to measure cell survival fraction.A single-hit multi-target model was used to fit cell survival curve and calculate the sensitive enhancement ratio (SER).Influence of rhES combined with X-ray radiation on cell cycle and apoptosis was measured by flow cytometry.Expressions of Cyclin B1,Cyclin D1,Bcl-2 and Bax mRNAs were determined by RT-PCR.Protein expressions of HIF-1α,VEGF,and VEGFR were determined by Western blot.Results D0,Dq and SF2 value of KYSE-150 cells decreased along with the concentration of rhES.At D0dose,the SER for 100 and 200 μg/ml rhES was 1.14 and 1.27,respectively.Compared with the radiation alone group,the apoptosis rate and bax expression increased,while the expressions of VEGF and HIF-1α decreased in the combination group (t =7.97,3.02,117.55,7.22,P ＜ 0.05).Conclusions rhES has radiosensitive effect on esophageal carcinoma cells KYSE-150 in vitro by inhibiting the expressions of HIF-1α and VEGF,regulating bax expression,and inducing apoptosis.