蓝光照射姜黄素对乳腺癌MCF-7细胞的光动力杀伤效应研究

摘要

Objective:To investigate the effect ofcurcumin mediated photodynamic therapy (CUR-PDT) on proliferation and cell morphology of Human Breast cancer MCF-7 cells.Study the photosensitve effect of curcumin so as to provide theoretical basis for clinical treatment.Methods:The PDT treatment was performed on vitro cultured human breast cancer MCF-7 cells,which used curcumin as photosensitizer and 455 nm blue light-emitting diode as light source.MTT assay was used to evaluate different incubation time (2h,3h),different concentration ofcurcumin (10 μmol/L,20 μmol/L,40 μmol/L,80 μmol/L) and different energy densities of light (1.2 J/cm2,2.4 J/cm2,4.8 J/cm2) on the effect of the inhibition rate.Finally the group of 40 μmol/L curcumin with 2.4 J/cm2 and 4.8 J/cm2 irradiation was selected to explore the pro-apoptosis effect of photosensitized curcumin on MCF-7 cells.The morphology changes of the breast cancer cells were observed by Hoechst 33342 staining.Results:The inhibition rate of cells increased as the incubation time prolonged,which was in time-dependent manner.The growth inhibition rates rise gradually along with the increase of curcumin concentration and light doses,exhibiting concentration and light dosage-dependent manner.Cell population in curcumin alone group and irradiation groups declined obviously compared with the control group.The alternation became more obvious as the energy density increased.Typical morphologic features of apoptosis,characterized by marked chromatin condensation,nuclear pyknosis and fragmentation,and the appearance of apop totic bodies,were observed under fluorescence microscopy after Hoechst 33342 staining.Conclusions:Illumination can reinforce the inhibition and apoptosis of MCF-7 breast cancer cells caused by curcumin.The incubation time,concentration of curcumin and the dosage of light are key factors involved in photodynamic therapy.%目的:探讨蓝光照射姜黄素(Curcumin,CUR)介导的光动力疗法(CUR-PDT)对乳腺癌MCF-7细胞增殖及形态学的影响.方法:以CUR作为光敏剂、455 nm的蓝色发光二极管(LED)为光源的光动力疗法作用于体外培养的乳腺癌MCF-7细胞.利用MTT法分别检测不同姜黄素孵育时间(2h,3h)、姜黄素浓度(10 μmol/L,20μmol/L,40 μmol/L,80μmol/L)及光剂量(1.2 J/cm2,2.4 J/cm2,4.8 J/cm2)对MCF-7细胞生长的抑制效应,最终选定在40 μmol/L的浓度下,分别用2.4 J/cm2、4.8 J/cm2的剂量照射姜黄素,检测能量密度改变后光敏化姜黄素对细胞的杀伤作用,Hoechst 33342荧光染色观察细胞光敏化姜黄素对MCF-7细胞形态的改变及促凋亡效应.结果:细胞抑制率随光敏剂孵育时间延长而增大,呈时间依赖效应,光敏化姜黄素对细胞增殖具有显著的抑制作用并可诱导凋亡,且呈浓度-光剂量依赖效应;Hoechst 33342荧光染色显示,与对照组相比,单独姜黄素组及照光组细胞明显减少,随剂量增加现象越明显,细胞呈典型凋亡形态改变,核染色质凝聚、核固缩、核碎裂,出现凋亡小体.结论:蓝光对姜黄素抑制MCF-7细胞生长及诱导凋亡具有增敏作用,姜黄素孵育时间、姜黄素浓度、光剂量均是影响CUR-PDT的重要因素.