胃癌细胞肿瘤坏死因子受体的研究

Study on tumor necrosis factor receptor of human gastric cancer cells

目的 探讨人胃癌细胞肿瘤坏死因子受体 ( TNFR)的数目与胃癌细胞分化程度以及与肿瘤坏死因子突变体 ( TNF- m)细胞毒效应之间的关系。方法 以12 5I- TNF- m为配体 ,用放射配体结合分析法 ,检测了高、中、低不同分化程度的体外培养胃癌细胞 ( MKN2 8、SGC790 1、MKN4 5)的 TNFR,同时用 MTT比色法研究了 TNF- m对三株胃癌细胞的细胞毒效应。结果 三株胃癌细胞 TNFR数目分别为每细胞 9.8× 10 -12 nmol、5.6× 10 -12 nmol、3.2× 10 -12 nmol,三者之间比较 ,TNFR数目差异有显著性 ( P<0 .0 5)。解离常数基本一致 ,同一温度时三株胃癌细胞 TNF- m的内化率几乎相等 ,且呈温度依赖关系。TNFR的半衰期大约为 90分钟 ,胞膜与胞浆 TNFR数目之比约为 1∶ 2 ,TNF- m对三株胃癌细胞的最大杀伤率分别为 86%、60 %、34 % ,差异有显著性 ( P<0 .0 5) ,且 39℃时的杀伤率高于37℃时的杀伤率。结论 胃癌细胞表面 TNFR数目与胃癌分化程度相关。 TNF- m的细胞毒效应与TNF数目及 TNF- m的内化量有关。

Objective To explore the relationship between the number of tumor necrosis factor receptors (TNFR) and the degree of differentiation of gastric cancer cells, and the relationship between the number of TNFR and the cytotoxicity of tumor necrosis factor mutant (TNF m). Methods With 125 I TNF m, the radio ligand binding assay was used to detect the TNFR on three gastric cancer cell lines (MKN28, SGC7901 MKN45) with from high to low degrees of differentiation. MTT colorimetric method was used to study the cytotoxicity of TNF m on the three gastric cancer cell lines in vitro. Results The number of TNFR of the three gestric cancer cells was 9.8×10 -12 nmol, 5.6×10 -12 nmol and 3.2×10 -12 nmol per cell respectively it differed significent from each other ( P <0.05) but the dissociation constant was basically the same. The rate of TNF m internalization of the three gastric cancer cells was nearly the same and temperature dependent. The half life of TNFR was about 90 mins. The ratio of membrane receptors to cytoplasm receptors was about 0.5. The maximum killing rate of TNF m was 86%, 60% and 34% for MKN28, SGC7901, MKN45 cells, respectively, which were significantly different ( P <0.05). Killing rate of TNF m to these cells at 39℃ was higher than at 37℃. Conclusions The number of TNFR on the surface of gastric cancer cells was associated with the degree of differentiation of gastric cancer cells. The cytotoxicity of TNF m was related to the number of TNFR and the rate of internalization of TNF m.