Theiss J C
Cytobios. 1980;29(115-116):159-63.
In two in vivo experiments, low doses of 5-methyl cytidine significantly suppressed the growth of urethan-induced lung tumours in strain A mice while higher doses were less effective. This inverse dose-response relationship mimics the previously reported effect of 5-methyl cytidine on mammary tumour growth in C3H mice. The finding that 5-methyl cytidine inhibits lung tumour growth as well as mammary tumour growth suggests this nucleoside may be an effective inhibitor of solid tumour growth in general. A study of the effect of 5-methyl cytidine on mouse lung tumour cell viability in vitro suggests that the direct cytotoxic effect of 5-methyl cytidine is dependent on the cell cycle. Since cell-cycle dependent agents do not inhibit lung tumour growth in vivo, 5-methyl cytidine probably inhibits mouse lung tumour growth indirectly by some effect on the host rather than by a direct cytotoxic effect on the lung tumour.
在两项体内实验中，低剂量的5-甲基胞苷显著抑制了乌拉坦诱导的A品系小鼠肺肿瘤的生长，而高剂量的效果则较差。这种剂量反应的反比关系类似于先前报道的5-甲基胞苷对C3H小鼠乳腺肿瘤生长的影响。5-甲基胞苷抑制肺肿瘤生长以及乳腺肿瘤生长的这一发现表明，这种核苷总体上可能是实体肿瘤生长的有效抑制剂。一项关于5-甲基胞苷对小鼠肺肿瘤细胞体外活力影响的研究表明，5-甲基胞苷的直接细胞毒性作用取决于细胞周期。由于细胞周期依赖性药物在体内并不抑制肺肿瘤生长，5-甲基胞苷可能是通过对宿主的某种作用而非对肺肿瘤的直接细胞毒性作用来间接抑制小鼠肺肿瘤生长。
