光动力疗法对C6胶质瘤细胞转化生长因子-β的影响

Effects of photodynamic therapy on transforming growth factor-B （TGF--B） secretion of C6 glioma cells

目的探讨C6胶质瘤细胞中转化生长因子-B（TGF—B）和光动力疗法（PDT）之间的关系，阐明PDT对C6胶质瘤的治疗效果的机制。方法以C6胶质瘤细胞系为对照组，实验组添加25nM血啉甲醚（HMME），再用240J／cm2PDT照射，依据光照时间公式中光源输出的光斑面积，计算出照射时间，利用酶联免疫吸附试验（ELISA）检测PDT处理前后，C6细胞上清液中的TGF—B的表达；提取HMME—PDT实验组细胞上清液为条件培养基，对照组细胞上清液为非条件培养基，培养人血管内皮细胞（HUVEC），使用MTT法观察HuVEC的增殖情况；建立Wistar大鼠脑胶质瘤模型，以HMME联合PDT疗法为HMME—PDT组，生理盐水治疗为非治疗组，免疫组化法观察胶质瘤血瘤屏障中CD31的表达。结果与未处理组c6比较，经HMME—PDT处理的C6细胞上清液TGF-B含量明显降低（P〈0．01）；经HMME—PDT处理的c6细胞条件培养基可以抑制HuVEC的增殖，与非条件培养基组比较，差异有统计学意义（P〈0．01）；与非治疗组比较，HMME—PDT组的大鼠脑胶质瘤血瘤屏障CD31表达明显降低（P〈0．01）。结论HMME联合PDT降低c6细胞旁分泌TGF—B，明显抑制胶质瘤血瘤屏障血管生成，为PDT从抑制胶质瘤细胞旁分泌角度，抑制胶质瘤血管新生奠定基础，具有重要的临床应用前景。

Objective To study the relationship between the photodynamic therapy （PDT） and the transforming growth factor--B（TGF--B） of C6 glioma ceils, and to clarify the mechanism of therapeutic effects of PDT on C6 glioma cells. Methods C6 glioma cell lines were control group. The experimental group was added 25nM hematoporphyrin monomethyl ether （HMME）, and then was irradiated by 25 J/eraz PDT. The irradiation time based on the spot area of the light output was calculated by the irradiation time formula. Tested the expression of TGF in the supernatant of C6 glioma cells before and after PDT by enzyme--linked immunosorbent assay （ELISA）. Extracted the supernatant of HMME--PDT experi- mental group as conditioned medium, and the supernatant of control group as non--conditioned medium, and then cultured human vascular endothelial cells （HUVEC） on the two mediums respectively. The proliferation of HUVEC was observed by using MTT method, and established the brain glioma model of Wistar rats. The HMME united PDT therapy group was HMME--PDT group and the saline treatment group was non--treated one, and observed the expression of vessel in glioma blood vessel barrier by im- munohistochemistry method. Results Compared with the untreated group, the content of TGF- Bof C6 glioma cell was significantly reduced in the supernatant of HMME-- PDT treated group （P ~ 0.01）. Compared with non--conditioned medium the conditioned medium treated by HMME--PDT could inhibit the proliferation of HUVEC （P 〈5 0.01）. Compared with non--treated group, the CD31expression of rat glioma blood barrier was significantly decreased （P ~ 0.01）. Conclusions HMME--PDT decreased the paracrine TGF--Bof C6 glioma cells to significantly inhibit the vascularization of glioma blood barrier. It lays the foundation of PDT inhibiting the vascularization of glima that PDT inhibited the paracrine of C6 glioma cells, so PDT has important clinical application in the future.