光敏剂PpIX亚细胞分布方式对食管癌细胞光动力学效应的影响  

Effects of subcellular localization pattern of PpIX on photodynamic efficiency in esophageal cancer cells

作　　者：汲振余[1] 范天黎[2] 赵立群[1] 杨小静[1] 裘一兵[1] 张聚真[1] 张亚冰[1] 孙予[1] 裘宋良[1] 杨观瑞[1] 

机构地区：[1]郑州大学医药科学研究院肿瘤室,河南省郑州市450052 [2]郑州大学基础医学院肿瘤室,河南省郑州市450001

出　　处：《世界华人消化杂志》2009年第16期1602-1608,共7页World Chinese Journal of Digestology

基　　金：国家自然科学基金资助项目;No.30873002~~

摘　　要：目的:探讨不同来源的光敏剂PpIX在食管癌细胞中的亚细胞分布与光动力学效应的关系.方法:KYSE-450、KYSE-70和Het-1A细胞分别用ALA和外源性PpIX以及Mito Tracker Green处理,相差荧光显微镜观察不同来源的PpIX在细胞内的定位.利用JC-1-流式细胞方法检测ALA-PDT和PpIX-PDT后细胞线粒体膜电位(ΔΨm)的改变.利用电镜观察ALA-PDT和PpIX-PDT后细胞线粒体的超微结构,观察PpIX的不同细胞分布形式对线粒体损伤的形态学改变.MTS法测定PDT处理后的细胞存活率.结果:由ALA产生的内源性光敏剂PpIX荧光主要分布在线粒体,与Mito Tracker Green显示的线粒体荧光分布在相同的区域,而外源性PpIX荧光信号则弥漫性分布于整个细胞质.KYSE-450、KYSE-70和Het-1A细胞经ALA-PDT12h后,膜电位受损细胞分别达到22%、52%和33%,而外源性PpIX-PDT别12h后线粒体受损细胞率仅分别为15%、14%和18%.电镜观察结果显示,ALA-PDT后仅1h一些线粒体即已出现受损状态,可见线粒体内嵴不明显,出现空泡和膨胀.但外源性PpIX-PDT后1h细胞内大部分线粒体仍保持完整结构.ALA-PDT的细胞杀伤效果明显好于外源性PpIX-PDT.结论:光敏剂的不同亚细胞定位影响了食管癌细胞PDT的功效,PDT造成的线粒体的损伤在肿瘤细胞杀伤过程中起非常重要的作用,提示以线粒体为靶点的光敏剂是未来光敏剂研制的重点.AIM： To study the effects of subcellular localization pattern of PpIX on photodynamic efficiency in esophageal cancer cell lines. METHODS： KYSE-450, KYSE-70 and Het-lA cells were treated with ALA, exogenous PpIX and MitoTracker, respectively. The subcellular localization patterns of PpIX were observed using fluorescence microscopy. Mitochondrial transmembrane potential （△ψm） after ALA-PDT and PpIX-PDT was measured using JC-1 flow cytometry. The morphological study of mito- chondria after ALA-PDT and PpIX-PDT was performed with electron microscopy. MTS was used to examine the cell survival rate. RESULTS： The granular patterns and distribution of fluorescence in the extranuclear fraction of the cells were similar for both ALA-derived endog- enous PpIX and the MitoTracker in all cell lines; however, exogenous PpIX was diffusely distributed in the whole cytoplasm of ceils. After 12 h of ALA-based PDT, the percentages were increased to 22%, 52% and 33% in the KYSE-450, KYSE-70 and Het-lA cell lines, respectively; where only 15%, 14% and 18% of the depolarized cell fractions were seen following PDT with exogenous PpIX. As early as I h after photodynamic treatment, some of the mitochondria were already damaged by ALA- PDT with unclear cristae, vacuoles and swelling; while the mitochondrial ultrastructure was still well preserved I h later following PDT with exogenous PpIX. ALA-mediated PDT was significantly more efficient than PDT with exogenous PpIX in killing cells in all the 3 ceil lines. CONCLUSION： Different subcellular location of photosensitizer may affect the PDT efficacy. Mitochondria are more sensitive and may be important targets for PDT. This finding suggests that new photosensitizers with mitochondrially- localizing property may be designed for improvement of PDT effectiveness in the future.

关 键 词：食管癌 光动力学 光敏剂 氨基酮戊酸 原卟啉IX 

分 类 号：R735.1[医药卫生—肿瘤] R73-35[医药卫生—临床医学]