Makino R, Hayashi K, Sugimura T
Nature. 1984;310(5979):697-8. doi: 10.1038/310697a0.
In rats, partial hepatectomy induces reasonably synchronized DNA replication in the remaining liver after approximately 20 h. Events occurring during the earlier stages of liver regeneration are of interest because they may tell us how cells in vivo respond when they move from a differentiated resting state (G0 phase) to a proliferative state. We report here that the expression of the c-myc oncogene is increased up to 10-15-fold of the normal level within 1-3 h after partial hepatectomy. This expression begins to decrease rapidly after 4 h and has returned to less than double the normal level after 8 h, at which time replicative DNA synthesis has still not begun. A still larger increase in c-myc transcription (approximately 600-fold) is observed in the liver when protein synthesis is inhibited by an injection of cycloheximide. These findings suggest the existence of a short-lived protein that is synthesized soon after partial hepatectomy, and which suppresses the expression of c-myc.
在大鼠中，部分肝切除术后约20小时，剩余肝脏会诱导出相当同步的DNA复制。肝脏再生早期发生的事件备受关注，因为它们可能告诉我们体内细胞从分化静止状态（G0期）转变为增殖状态时的反应方式。我们在此报告，部分肝切除术后1 - 3小时内，c - myc癌基因的表达增加至正常水平的10 - 15倍。这种表达在4小时后开始迅速下降，8小时后降至正常水平的两倍以下，而此时复制性DNA合成仍未开始。当通过注射环己酰亚胺抑制蛋白质合成时，在肝脏中观察到c - myc转录有更大幅度的增加（约600倍）。这些发现表明，部分肝切除术后不久会合成一种短寿命蛋白质，它会抑制c - myc的表达。
