Smith J R, Nakanishi M, Robetorye R S, Venable S F, Pereira-Smith O M
Huffington Center on Aging, Baylor College of Medicine, Houston, Texas 77030, USA.
Exp Gerontol. 1996 Jan-Apr;31(1-2):327-35. doi: 10.1016/0531-5565(95)00026-7.
The identification of the DNA synthesis inhibitory gene SDI1 by investigators studying cell senescence, tumor suppression, cell cycle control and differentiation suggest a key regulatory role for this gene. To better understand the growth regulatory activity of this gene we proceeded with the experiments described here. The data demonstrate that SDI1 is an important downstream effector of p53, but here we report that it can also cause inhibition of DNA synthesis in several immortal human cell lines, independent of p53 or Rb status. Levels of SDI1 mRNA expression in immortal cells are consistently much lower than that of normal cells, indicating that immortalization is not compatible with high expression of SDI1. These results highlight the complex nature of regulation of this gene and its mode of action.
研究细胞衰老、肿瘤抑制、细胞周期调控和分化的研究人员对DNA合成抑制基因SDI1的鉴定表明该基因具有关键的调控作用。为了更好地理解该基因的生长调控活性，我们进行了此处所述的实验。数据表明SDI1是p53的重要下游效应物，但我们在此报告，它也可在几种永生化人类细胞系中抑制DNA合成，而与p53或Rb状态无关。永生化细胞中SDI1 mRNA的表达水平始终远低于正常细胞，这表明永生化与SDI1的高表达不兼容。这些结果突出了该基因调控的复杂性及其作用方式。
