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文中报道了重组人肿瘤坏死因子（ｒｈＴＮＦ）对人结肠癌细胞株ＳＷ－４８０的克隆抑制和细胞毒作用。改良噻唑兰（ＭＴＴ）法表明ＴＮＦ在６００００ｕ／ｍｌ时才有明显的细胞毒作用说明ＳＷ－４８０对ＴＮＦ低度敏感，而且无剂量依赖关系．但克隆抑制试验表明１０ｕ／ｍｌ就可明显抑制ＳＷ－４８０集落的生长，并有剂量依赖性，且在剂量１５０ｕ／ｍｌ以上时抑制作用随时间而增强．３Ｈ－ＴｄＲ掺入测定的ＴＮＦ抑制ＳＷ－４８０细胞ＤＮＡ合成和ＭＴＴ法测定的细胞毒曲线一致说明ＴＮＦ对ＳＷ－４８０的主要作用是抑制ＤＮＡ合成．ＴＮＦ对ＳＷ－４８０抑制后超微结构变化：最初是胞膜出现微孔，然后细胞内线粒体变性，溶解，核固缩，溶解，最后细胞溶解．这些结果与ＭＴＴ法细胞毒试验及３Ｈ－ＴｄＲ掺入试验相结合说明ＴＮＦ对ＳＷ－４８０杀伤作用主要针对细胞核内外染色体的ＤＮＡ合成上．
The cloning inhibition and cytotoxicity of recombinant human tumor necrosis factor (rhTNF) on human colon cancer cell line SW-480 was reported. The modified thiazolyl (MTT) method showed that TNF was only cytotoxic at 60 000 u/ml suggesting that SW-480 is sensitive to low levels of TNF, and there is no dose-dependent relationship. However, cloning inhibition test showed that the growth of SW-480 colonies was significantly inhibited by 10u/ml in a dose-dependent manner, and the inhibitory effect increased with time at a dose of 150u/ml or more. 3H-TdR incorporation of TNF-inhibited DNA synthesis in SW-480 cells and cytotoxicity curves determined by MTT assay consistently demonstrated that the main effect of TNF on SW-480 is inhibition of DNA synthesis. The ultrastructural changes of TNF in response to SW-480 inhibition were initially micropores in the cell membrane, and then intracellular mitochondrial degeneration, dissolution, nuclear condensation, lysis, and finally cell lysis. These results were combined with MTT cytotoxicity assay and 3H-TdR incorporation assay to demonstrate that the killing effect of TNF on SW-480 is mainly directed at the DNA synthesis of intra- and extra-chromosomal chromosomes.