Fas、Fas配体和IFN-γ在胃癌中的表达

目的：研究Fas、Fas配体(FasL)和干扰素-γ(IFN-γ)在胃癌中的表达规律及可能的意义。方法：在石蜡包埋的58例胃癌组织和其中相对应的53例癌旁正常组织中，采用免疫组化方法检测Fas、FasL蛋白的表达，采用原位杂交方法检测IFN-γ mRNA的表达。结果：胃癌组织中胃癌细胞和癌旁组织中胃上皮细胞Fas阳性率分别为19．0％和64．2％，胃癌组阳性率明显低于癌旁组(χ^2=23．46；P=0．00)。胃癌组织中胃癌细胞和癌旁组织中胃上皮细胞FasL阳性率分别为63．8％和45．3％，胃癌组阳性率明显高于癌旁组(χ^2=3．83；P=0．05)。癌旁组织中胃上皮细胞，IFN-γ阳性率为49．1％，而胃癌组织中未发现一例阳性。结论：胃癌细胞Fas—FasL系统平衡失调，本研究中胃癌细胞不表达IFN-γ，可能与胃上皮细胞癌变及免疫逃逸有关。

Expression of Fas, FasL and IFN-γ in gastric cancer

OBJECTIVE: To study the expression of Fas, Fas ligand (FasL) and IFN-gamma in gastric cancer and its possible significance. METHODS: Fifty-eight gastric paraffin wax embedded cancer tissues and fifty-three normal tissues adjacent gastric cancer were tested for the expression of Fas and FasL protein by immunohistochemistry and IFN-gamma mRNA by in situ hubridisation respectively. RESULTS: The positive rate of Fas in cancer cells of gastric cancer tissues was significantly lower than that in gastric epithelial cells of the tissues adjacent cancer(19.0% and 64.2%, respectively; chi 2 = 23.46, P = 0.00). The positive rate of FasL in cancer cells of gastric cancer tissues was significantly higher than that in gastric epithelial cells of the tissues adjacent cancer(63.8% and 45.3%, respectively; chi 2 = 3.83, P = 0.05). The positive rate of IFN-gamma in cancer cells of gastric cancer tissues was significantly lower than that in gastric epithelial cells of the tissues adjacent cancer(0.0% and 49.1%, respectively; chi 2 = 37.16, P = 0.00). CONCLUSION: The Fas-FasL system was unbalanced, and the expression of IFN-gamma was low in gastric cancer cells in this study. These may be related to the carcinogenesis of gastric epithelial cells and might be responsible for the immune escape of these cells.