姜黄素对人肾癌ACHN细胞放疗增敏作用的实验研究

目的研究姜黄素对人肾癌ACHN细胞放射增敏作用并探讨其作用机制。方法不同浓度姜黄素作用于ACHN人肾癌细胞24h后，MTT法检测姜黄素药物毒性；克隆形成实验观察其对放射敏感性的影响；流式细胞术检测姜黄素诱导细胞的凋亡率、细胞周期分布。结果姜黄素对人肾癌ACHN细胞有明显的抑制作用，可引起细胞的凋亡，且存在剂量和时间依赖；较低浓度的姜黄素（5μmol和10μmol）即可降低放射后ACHN细胞的克隆形成率，其放射增敏比分别为1．61及2．36；姜黄素及姜黄素联合辐射组的细胞周期阻滞在辐射敏感时相G2／M期；结论低剂量的姜黄素对人肾癌ACHN细胞有放射增敏作用，其机制可能与其引起细胞的凋亡增加，细胞周期阻滞有关。

Radiosensitization by curcumin on human renal cell carcinoma cell line ACHN

Objective To investigate the radiosensitization by curcumin on human renal cell carcinoma cell line ACHN and its possible mechanism in vitro. Methods The human renal cell carcinoma cell line ACHN was treated with curcumin of different concentrations for 24 h respectively. The MTT assay was used to evaluate the cytotoxic effects of curcumin on ACHN cells and clonogenic assay was employed to observe the effects on the radiosensitivity of the ACHN quantified by calculating the sensitive enhancement ratio （SER）. The flow cytometry was utilized to observe the apoptosis of ACHN cells induced by curcumin and the cell-cycle of ACHN cells in response to X-ray irradiation. Results The curcumin could significantly inhibit the proliferation of ACHN ceils, with obvious dose- and time-dependent effects. Subtoxic dose of curcumin at 5 μmol and 10 μmol could significantly reduce the clonogenic activity and enhance the radiosensitivity of ACHN cells with a SER of 1.61 and 2.36 respectively. Irradiation or curcumin resulted in cell cycle arrest at G2/M phase in ACHN cells. Conclusion Low-dosage curcumin can enhance the radiosensitivity of the human renal cell carcinoma ACHN cells in vitro. The mechanism may involve the increased apoptosis and prolonged cell cycle arrest induced by the combined treatment.