摘要
目的：探讨伴刀豆蛋白Ａ（ＣｏｎＡ）对人胃癌细胞肿瘤坏死因子受体（ＴＮＦＲ）的调节机制及肿瘤坏死因子突变体（ＴＮＦ－ｍ）细胞毒效应与ＴＮＦＲ之间的关系。方法：以１２５Ｉ－ＴＮＦ－ｍ作为放射配体，用放射配体结合分析法、ＭＴＴ比色法对ＣｏｎＡ作用前后的人胃癌细胞（ＳＧＣ７９０１）ＴＮＦＲ的数目，亲和力，以及ＴＮＦ－ｍ的细胞毒效应进行了检测，结果：ＣｏｎＡ可快速增加细胞表面ＴＮＦ－ｍ的结合位点（０．５６×１０－１１对０．９１×１０－１１ｎｍｏｌ·细胞－１，Ｐ＜０．０１）而不影响受体的亲和力（Ｋｄ：２．７８×１０－１０对２．６３×１０－１０ｍｏｌ·Ｌ－１，Ｐ＞０．５）。ＣｏｎＡ不增加受体蛋白的合成和胞浆受体的数目；ＣｏｎＡ作用组ＴＮＦ－ｍ的内化和降解（分别为１．２４×１０－６和０．１８×１０－６ｎｍｏｌ）显著低于对照组的内化和降解（分别为０．６×１０－６和０．０７×１０－６ｎｍｏｌ）；ＣｏｎＡ作用组ＴＮＦ－ｍ对胃癌细胞的最大抑制率（８．４％）显著低于对照组ＴＮＦ－ｍ的最大抑制率（６０％）、Ｐ＜０．０１。结论：伴刀豆蛋白Ａ通过抑制ＴＮＦＲ的内化而增加膜ＴＮＦＲ的数目；ＴＮＦ－ｍ的生物效应与ＴＮＦＲ介导的信号传递（受体后?
To explore the modulation of tumor necrosis factor receptor (TNFR) of human gastric cancer cells (SGC 7901 ) by ConA and the relationship between the cytotoxicity of tumor necrosis factor mutants (TNF m) and TNFR. Methods: With self made 125 I TNF m as the radio ligand, radio lignad binding assay, MTT colorimetric method, priton synthessis inhibition experiment were applied to detect the number and affinity of TNFR on SGC 7901 , the internalization and degradation of 125 I TNF m, and the cytotoxicity of TNF m, before and after the treatment by ConA and at various temperatures and times. Results: ConA could rapidly increase the number of the binding cites of 125 I TNF m (TNFR) on the surface of SGC 7901 cells (0 56×10 -11 vs 0 91×10 -11 nmol·cell -1 , P<0 05) , with no effect on the affinity of the numbers (2 78×10 -11 vs 2 63×10 -11 mol·L -1 ). The increase of the number of the binding cites was dependent on time, dose and temperatures. ConA did not improve synthessis of the receptor priton, nor did it increase the number of TNFR in cytoplasm. The internalization and degradation of 125 I TNF m in ConA treating group 1 24×10 -6 nmol·(5×10 5 cells) -1 and 0 18×10 -6 nmol·(5×10 5 cells) -1 respectively was remarkably lower than that in the control group 0 6×10 -6 and 0 07×10 -6 nmol·(5×10 5 cells) -1 respectively . The maximum inhibtion rate of SCG 7901 cells by TNF m in ConA treating group (8 4%) was significantly lower than that by control group (60%). Conclusions: ConA could rapidly increase the number of TNFR on the membrance ty inhibition the internalization of TNFR. The biological effect of TNF m was closely associated with TNFR mediated signal transduction (post receptor mechanism).
出处
《中国药理学通报》
CSCD
北大核心
1996年第6期523-526,共4页
Chinese Pharmacological Bulletin
关键词
伴刀豆蛋白A
肿瘤坏死因子
受体
突变体
胃癌
radio ligand binding assay
MTT colorimetric method
tumor necrosis factor receptor
tumor necrosis factor mutant
ConA
