羟基喜树碱对宫颈癌HeLa细胞的放射增益作用及影响因素的研究

Radiosensitization Effect of Hydroxycampotothecin on HeLa Cells and Its Influencing Factors

目的研究羟基喜树碱(HCPT)对人宫颈癌HeLa细胞系的放射增益作用以及给药时序、药物浓度和作用时间对放射增益作用的影响。方法MTT法测定HCPT作用于HeLa细胞的IC50。应用克隆形成和单击多靶数字模型方法检测HCPT的放射增益作用及不同给药时序、不同药物浓度和不同作用时间的细胞存活率及放射增益比(SER)。结果HCPT对HeLa细胞的IC50为62.1μmol/L。取2.85μmol/L(IC20)HCPT联合射线照射作用HeLa细胞,先给药后照射组SER=1.187、给药中照射组SER=1.573、先照射后给药组SER=1.850;而用28.5μmol/L(10×IC20)HCPT作用HeLa细胞,先照射后给药组SER=1.897;HCPT作用HeLa细胞4 h内放射增益作用改变明显,其后延长作用时间对放射增益无明显影响。结论HCPT对HeLa细胞具有放疗增益作用,其增益作用有时序、浓度和时间依从性。

Objective To study the radiation sensitizing effect of hydroxycampotothecin （HCPT） on human cervical carcinoma （HeLa）cell and the influencing factors （schedule, concentration and timing）. Methods The cytotoxicity of HCPT on HeLa cells was measured by MTT assay. HeLa cell was treated in vitro with different doses of radiation alone or radiation with drug by various schedules, different concentrations and exposing durations. Colony forming assaying and single-hit multitarget model were used to perform survival fraction analysis and plotting survival curve. Results The growth inhibition of HCPT on HeLa cell was dependent on concentration. The IC50 was 62.1 μmol/L. The sensitive enhancement ratio（SER）of 1. 850, 1. 573 and 1. 187 was observed when radiation was given prior to, concurrently with or immediately after treatment with HCPT 2.85 μmol/L （IC20） for 4 h. When radiation was prior to HCPT, SER was 1. 897 after the HeLa cells were treated with 10 IC20 for 4 h. The enhancement effect occurred significantly within 4 h. Conclusion HCPT had a radiosensitization effect in vitro on HeLa cells and it was dependent on schedule, concentration and timing of HCPT.