Pardee A B
Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA.
Science. 1989 Nov 3;246(4930):603-8. doi: 10.1126/science.2683075.
Cells prepare for S phase during the G1 phase of the cell cycle. Cell biological methods have provided knowledge of cycle kinetics and of substages of G1 that are determined by extracellular signals. Through the use of biochemical and molecular biological techniques to study effects of growth factors, oncogenes, and inhibitors, intracellular events during G1 that lead to DNA synthesis are rapidly being discovered. Many cells in vivo are in a quiescent state (G0), with unduplicated DNA. Cells can be activated to reenter the cycle during G1. Similarly, cells in culture can be shifted between G0 and G1. These switches in and out of G1 are the main determinants of post-embryonic cell proliferation rate and are defectively controlled in cancer cells.
细胞在细胞周期的G1期为S期做准备。细胞生物学方法提供了有关周期动力学以及由细胞外信号决定的G1期亚阶段的知识。通过运用生化和分子生物学技术来研究生长因子、癌基因和抑制剂的作用，G1期期间导致DNA合成的细胞内事件正迅速被发现。体内许多细胞处于静止状态（G0期），DNA未复制。细胞可在G1期被激活以重新进入细胞周期。同样，培养中的细胞也可在G0期和G1期之间转换。这些进出G1期的转换是胚胎后细胞增殖速率的主要决定因素，并且在癌细胞中受到缺陷控制。
