光动力作用诱导人胰腺癌细胞凋亡的实验研究

Experimental study of apoptosis of human pancreatic cancer cells induced by photodynamic therapy

目的研究光敏剂血卟啉光动力作用对人胰腺癌细胞Panc-1的体外杀伤效应及其主要机制。方法将光敏剂浓度、光照剂量两个因素按不同水平分组,以CCK-8实验的OD值为检测指标并转换为细胞存活率,研究两个因素对光动力作用的影响及其规律。在此基础上,依次以透射电镜、荧光显微镜、流式细胞仪测定不同处理强度的光动力作用后细胞凋亡及坏死的特点,探讨光动力杀伤肿瘤细胞的主要机制。结果随着光敏剂浓度和光照剂量的增加,PDT后Panc-1细胞存活率相应下降,但单独给予光敏剂和光照均不对细胞存活率产生影响。 PDT后细胞出现凋亡和坏死,二者比例随光敏剂浓度和光照剂量的增加而增加,但始终表现为凋亡率>坏死率。结论血卟啉光动力治疗对人胰腺癌细胞株Panc-1具有明确的杀伤作用,但是光敏剂和激光照射本身并不具有独立的杀伤效应。光敏剂浓度、光照剂量两个影响因素在一定范围内与PDT效应之间成正相关的关系。 PDT破坏肿瘤细胞的作用机制主要在于诱导细胞凋亡。

Objective To study the killing effect in vitro and mechanism of photodynamic therapy of hematoporphrin on human pancreatic cancer cells Panc-1.Methods The photosensitizer concentration and light dose were divided into groups at different levels. OD450 of CCK-8 test was the detection index and then was converted to cell survival,to discuss effect and its rule of these two factors on PDT.On this basis,the characteristics of apoptosis and necrosis of cells treated by PDT were successively measured with transmission electron microscopy,fluorescence microscope, and flow cytometry to study the main mechanism of killing effect of PDT..Results With photosensitizer concentration and light dose increased,Panc-1 cell survival decreased accordingly,but giving photosensitizer or light alone had no PDT effect. PDT may cause apoptosis and necrosis of cells,and the rate of them would increase with the increase of photosensitizer concentration and light dose,but rate of apoptosis always larger than rate of necrosis...Conclusions PDT with hematoporphyrin on human pancreatic cancer cells Panc-1 have clear killing effect,but photosensitizer and light itself have no PDT effect. Photosensitizer concentration and light dose show positive correlation with PDT effect in a certain extent. The main mechanism of PDT on Panc-1 cells is that PDT may induce apoptosis.