摘要
目的:探讨缺氧信号的激活对光动力学疗效的影响。方法:利用免疫组化方法检测32例食管早期癌患者光动力学疗法(PDT)治疗前组织中HIF-1α蛋白的表达,分析与PDT疗效的关系;利用食管上皮细胞Het-1A以氯化钴(CoCl2)化学诱导HIF-1α的稳定高表达,western blot测定HIF-1α蛋白质水平;应用光敏剂5-ALA孵育细胞,PDT处理,MTS法测定细胞存活活性,并利用TdT流式细胞测定细胞凋亡率。结果:HIF-1α蛋白的表达在食管早期癌患者NR组表达阳性率为60.0%,CR组表达阳性率为16.7%,两者有显著性差别(P<0.05);Het-1A细胞经CoCl2孵育4 h可诱导HIF-1α蛋白的高表达;PDT后高表达HIF-1α的细胞具有较高的细胞存活率,不同浓度CoCl2诱导的不同HIF-1α蛋白质水平与PDT后细胞存活活性相一致,且细胞凋亡率由未诱导时的16%降低至4%。结论:高表达HIF-1α蛋白的食管早期癌患者PDT疗效较差;缺氧信号的激活使Het-1A细胞PDT效果下降,HIF-1α部分通过抑制PDT引起的细胞凋亡而抵御PDT效应。提示HIF-1α可作为治疗靶基因,降低肿瘤组织HIF-1α表达水平可能有助于改善PDT临床疗效。
Objective ： To study the effect of hypoxia signaling pathway activation on photodynamic therapy efficacy. Methods ： Expressions of HIF-1α in 32 cases of early esophageal cancer before PDT were tested by Immunohistochemistry for analyzing its effects on photodynamic therapy efficiency. HIF-1α in Het-1A cells was induced by cobalt chloride incubation. Cells were treated with 5-ALA followed by PDT. HIF-1α protein level was tested by western blot, and the cell viability was tested by MTS methods. Results ： There was a significantly difference of HIF-1α positive rates between early esophageal cancer NR （60.0 % ） and CR （ 16.7 % ） （ P 〈 0.05）. High expression of HIF- 1α in Het- 1A cells could be induced by cobalt chloride incubation for 4h, and the cells with HIF-1α over-expression had higher cell viability after PDT which correlated well with the results of CoCl2-induced HIF-1α expression. ALA - PDT induced 16% of the apoptotic cells. But in the cells with CoCl2-induced expression of HIF-1α,ALA-PDT only induced 4% of the apoptotic cells. Conclusion ： High expression of HIF-1α in early esophageal cancer correlates with poor PDT outcomes. The activation of hypoxia signaling pathway may render cells resistant to PDT, and the attenuated PDT efficiency may partly due to the inhibition of apoptosis, suggesting a potential role of HIF-1α as a target gene for bettering PDT efficacy.
出处
《河南医学研究》
CAS
2006年第4期294-298,共5页
Henan Medical Research
基金
河南省自然科学基金项目资助(0611042500)
