Asoh K, Watanabe Y, Mizoguchi H, Mawatari M, Ono M, Kohno K, Kuwano M
Department of Biochemistry, Oita Medical School, Japan.
Biochem Biophys Res Commun. 1989 Jul 31;162(2):794-801. doi: 10.1016/0006-291x(89)92380-2.
Tumor necrosis factor (TNF)-resistant variant of human mammary cancer MCF-7 cell line was isolated by stepwise selection. The final TNF-resistant variant Tnf-1000 showed more than 100-fold higher resistance than the parental MCF-7 cell. Saturation kinetics for 125I-TNF binding showed that TNF-1000 cells had similar TNF receptor numbers as MCF-7 cells, but of a lower affinity. Induction of superoxide dismutase (SOD) was compared between MCF-7 and Tnf-1000 cells treated with TNF: SOD scavenges potentially toxic superoxide radicals. TNF induced more mitochondrial manganese SOD (SODm) in MCF-7 than in Tnf-1000 whereas there appeared to be no significant induction of cytosolic copper/zinc SOD (SODc) by TNF in both MCF-7 and Tnf-1000 cell lines. Acquirement of TNF-resistance in MCF-7 cells might be correlated with expression of SODm.
通过逐步筛选分离出了人乳腺癌MCF-7细胞系的肿瘤坏死因子（TNF）抗性变体。最终的TNF抗性变体Tnf-1000表现出比亲本MCF-7细胞高100多倍的抗性。125I-TNF结合的饱和动力学表明，TNF-1000细胞的TNF受体数量与MCF-7细胞相似，但亲和力较低。在用TNF处理的MCF-7和Tnf-1000细胞之间比较了超氧化物歧化酶（SOD）的诱导情况：SOD可清除潜在有毒的超氧自由基。TNF在MCF-7中诱导的线粒体锰超氧化物歧化酶（SODm）比在Tnf-1000中更多，而在MCF-7和Tnf-1000细胞系中，TNF对胞质铜/锌超氧化物歧化酶（SODc）似乎均无明显诱导作用。MCF-7细胞中TNF抗性的获得可能与SODm的表达相关。
