咖啡酸苯一酯对人宫颈癌HeLa细胞的放射增敏作用

目的 探讨咖啡酸苯一酯(CAPE)对人宫颈癌HeLa细胞的放射增敏作用。方法 将宫颈癌HeLa细胞经不同浓度的CAPE作用24 h,四甲基偶氮唑盐比色法(MTT)法检测细胞抑制效应与CAPE浓度的关系。将HeLa细胞设对照组和药物组,两组均经⁶⁰Coγ射线照射0、2、4、6和8 Gy,计数细胞克隆;另将HeLa细胞设对照组、CAPE组、单纯照射组、照射+CAPE组,流式细胞检测技术分析CAPE对细胞周期的影响。结果 CAPE对HeLa细胞的抑制率呈剂量依赖性增加(F=126.49~3654.88,P<0.01);细胞经⁶⁰Coγ射线照射后,HeLa细胞克隆存活率随着照射剂量的增加而降低(F=174.42~9422.81,P<0.01);相同剂量下,药物组的HeLa细胞克隆存活率低于对照组(F=120.14~251.91,P<0.01);药物组和对照组HeLa细胞的平均致死剂量(D₀)为1.45和1.82 Gy、准阈剂量(D_q)为1.89和3.21 Gy, 药物组较小,放射增敏比(SER)为1.26>1;与对照组相比, CAPE组及单纯照射组G₂/M期的细胞比例升高(P<0.01),而在照射+CAPE组则降低(P<0.01)。结论CAPE通过对人宫颈癌HeLa细胞G₂/M期的阻滞及可能抑制细胞亚致死性损伤修复能力,发挥放射增敏作用。

Radiation sensitization by CAPE on human HeLa cells of cervical cancer

Objective To study the radiosensitizing effect of caffic acid phenethyl ester(CAPE)on human cervical cancer HeLa cells.Methods MTT assay was used to measure the relation between the inhibition effect and CAPE concentrations by CAPE with different concentrations on HeLa cells for 24 hours.HeLa cells were divided into the control and experimental groups,both of which were given 0,2,4,6 and 8 Gy of 60Co γ-irradiation,respectively.The cell clones were counted.Meanwhile HeLa cells were divided into the control,CAPE,irradiation and combination groups.Flow cytometric analysis was adopted to detect the changes of cell cycle distribution induced by CAPE.Results The inhibition rate of CAPE acting on Hela cells increased with concentrations(F=126.49～3654.88,P＜0.01).HeLa cells cloning survival decreased with the increase of radiation dose(F=174.42～9422.81,P＜0.01).At the game radiation dose,HeLa cells cloning survival was less in experimental group than conlrol group(F=120.14～251.91,P＜0.01).The mean lethal dose(D0)(1.45 and 1.82 Gy)and the quasi-threshold dose(Dq)(1.89 and 3.21 Gy)of HeLa cells in experimental group decreased comparing with control group,SER was 1.26.Compared with the sole irradiation group,cells in G2/M phase of the CAPE group and the sole irradiation group increased(P＜0.01)while the combination group decreased(P＜0.01).Conclusions CAPE could increase the radiation sensitivity of HeLa cells by G2/M arrest and may be related to the inhibition of the sub-lethal damage repair.