金丝桃素光照对喉癌细胞Hep-2的影响

目的 探讨金丝桃素对喉癌细胞Hep-2的影响。方法 体外培养的喉癌细胞Hep-2分别加入终质量浓度为0．5、1．0、2．0、3．0、5．0μg／ml的金丝桃素，加药后1h给予照射能量为7．5J／cm^2的光照10min，另取喉癌细胞Hep-2分别加入终质量浓度为5．0、10．0、20．0、25．0μg／ml的金丝桃素，不给予光照。各实验组均设空白对照组。继续培养48h后，应用荧光显微镜、四甲基偶氮唑盐[3-(4，5-Dimethyl-2-thiazolyl)-2，5-diphenyl-2H tetrazolium bromide，MTT]法和流式细胞仪检测观察金丝桃素在光照和非光照条件下对喉癌细胞Hep-2的影响。结果 光镜下可见对照组喉癌细胞生长密集，细胞呈梭型或多角型，细胞彼此之间相接触。光照后小剂量金丝桃素组可见细胞数量明显减少，随着金丝桃素剂量的增加，细胞数量明显减少，在高剂量组可见细胞坏死。MTT结果显示光活化金丝桃素呈剂量依赖性抑制喉癌细胞的生长。流式细胞仪分析表明金丝桃素经光照后，可将喉癌细胞阻滞在G0-G1期，并诱导喉癌细胞凋亡；吖啶橙染色可见细胞胞膜出芽、染色质凝集、核片段化及凋亡小体等典型的细胞凋亡特征。金丝桃素单独应用，对喉癌细胞的抑制作用相对较弱。结论 金丝桃素经光照后，可有效抑制体外培养的喉癌细胞的增殖，并可诱导喉癌细胞凋亡。

Effects of hypericin associated with light irradiation on human laryngeal squamous cell carcinoma strain Hep-2

OBJECTIVE: To study effects of hypericin associated with light irradiation on human laryngeal squamous cell carcinoma strain Hep-2. METHODS: Using techniques of tumor cells culture in vitro, Hep-2 cells were exposed to different concentration hypericin as 0.5, 1.0, 2.0, 3.0, 5.0 microg/ml, then 10 minutes 7.5 J/cm2 light irradiation was given after an hour. Other groups Hep-2 culture cells were also exposed to different concentration hypericin as 5.0, 10.0, 20.0, 25.0 microg/ml, without light irradiation. In all groups, contrast groups were set up. And 48 hours later, growth characteristics of Hep-2 cells were studied by morphological observation, fluorescence microscope, MTT assay and flow cytometry. RESULTS: In normal contrast group, Hep-2 cells grew intensively and contacted with each other. However, cells which were treated with hypericin, combination with light irradiation were declined greatly. In higher dose hypericin group, necrosis could be found. MTT assay showed that hypericin associated with light irradiation inhibited growth of laryngeal cell with dose dependence manner. Flow cytometry showed that hypericin with light irradiation could block cell growth at G0/G1 phase, inducing apoptosis of laryngeal cell. Under fluorescence microscope, some sings of cell apoptosis including coagulation of chromatin, fragmentation of nuclei and apoptotic body could be found. CONCLUSION: Human laryngeal squamous cell carcinoma strain Hep-2 can be inhibited and induced into apoptosis by treated with hypericin combination with light irradiation.