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目的:探讨食管上皮Het1A细胞经诱导表达HIF1α后对光动力学效应的影响。方法:HIF1α的稳定高表达采用氯化钴(CoCl2)化学诱导法,并应用光敏剂5ALA处理细胞,光动力疗法(photodynamictherapy,PDT)光照射采用波长>600nm的红光光源,细胞存活活性以MTS法测定,应用Westernblot测定HIF1α蛋白质水平,RNA干扰采用脂质体转染法,并利用TdT流式细胞法测定细胞凋亡率。结果:Het1A细胞经100μmol/L的CoCl2孵育4h后可诱导HIF1α蛋白的高表达;PDT后高表达HIF1α的细胞具有较高的细胞存活活性,且细胞凋亡率由未诱导时的16%降低至4%;不同浓度CoCl2诱导的HIF1α蛋白质水平与PDT后细胞存活活性相一致;siRNA转染阻断HIF1α的诱导表达,细胞又恢复了对PDT的应答能力。结论:HIF1α在Het1A细胞中的高表达使PDT效果下降;HIF1α部分通过抑制PDT引起的细胞凋亡而抵御PDT效应。提示HIF1α可作为治疗靶基因,降低肿瘤组织HIF1α表达水平可能有助于改善PDT临床疗效。
Objective: To investigate the effect of HIF1α on the photodynamic effect induced by Het1A in esophageal epithelial cells. Methods: Stable high expression of HIF1α was induced by cobalt chloride (CoCl2), and the cells were treated with photosensitizer 5ALA. Photoluminescence (PDT) light was irradiated by a red light source with wavelength> 600nm. The cell viability was measured by MTS Method, the level of HIF1α protein was determined by Western blot, the RNA interference was performed by lipofection method, and the apoptosis rate was determined by TdT flow cytometry. Results: The HIF1α protein was highly expressed in Het1A cells incubated with 100μmol / L CoCl2 for 4h. HIF1α-positive cells were highly expressed after PDT, and the apoptotic rate decreased from 16% 4%. CoCl2-induced HIF1α protein levels were consistent with cell viability after PDT. SiRNA transfection blocked the induction of HIF1α expression and the cells regained their ability to respond to PDT. CONCLUSION: High expression of HIF1α in Het1A cells decreases the PDT effect. HIF1α partially protects against PDT by inhibiting PDT-induced apoptosis. It suggested that HIF1α could be used as a target gene for therapy. Reducing the expression of HIF1α in tumor tissue may help to improve the clinical efficacy of PDT.