Epidermal growth factor (EGF) is required only during the traverse of early G1 in PDGF stimulated density-arrested BALB/c-3T3 cells.
Epidermal growth factor (EGF) is required only during the traverse of early G1 in PDGF stimulated density-arrested BALB/c-3T3 cells.
复制标题
仅在 PDGF 刺激的密度停滞的 BALB/c-3T3 细胞穿越早期 G1 期间才需要表皮生长因子 (EGF)。
DOI：
10.1016/0014-4827(83)90285-9
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发表时间：
1983
影响因子：
3.7
通讯作者：
Pledger,WJ
中科院分区：
文献类型：
--
作者：
Leof,EB;VanWyk,JJ;O'Keefe,EJ;Pledger,WJ
密度阻滞的BALB/ C - 3t3细胞短暂暴露于PDGF，然后转移到仅含有EGF和生长激素C （Sm-C）的培养基中，在G0/G1滞后后开始DNA合成。胰岛素的超生理浓度可以代替Sm-C的需求。这个G0/G1滞后期被外源EGF存在的要求所分割。我们的数据表明，EGF只需要在G0/G1期的前半段（6 h）进行遍历，而不需要在G1后期进行遍历。亚生理血清Sm-C浓度也是EGF在G0/G1早期进展所必需的；然而，穿越G0/G1的最后一半并致力于DNA合成需要Sm-C的存在。结果表明，在G1后期，Sm-C的生理浓度是必需的。与人成纤维细胞或胶质细胞不同，BALB/c-3T3细胞对Sm-C的G0/G1穿越需求可能是由于内源性胰岛素样生长因子合成的差异。我们的数据与之前的报告非常一致，即EGF仅在G0/G1期的前8小时左右需要。在G0/G1的前6小时需要EGF可能是由于持续或重复的事件或多个不同的EGF需求事件造成的。
Density-arrested BALB/c-3T3 cells that had received a transient exposure to PDGF and were then transferred to medium containing only EGF and somatomedin C (Sm-C) began DNA synthesis after the G0/G1 lag. Supraphysiological concentrations of insulin could be employed to replace the Sm-C requirement. This G0/G1 lag phase was bisected by the requirement for the exogenous presence of EGF. Our data indicated that EGF was required during the traverse of only the first half of G0/G1 phase (6 h) and not during the traverse of late G1. Subphysiological serum concentrations of Sm-C were also necessary to be present with EGF for progression through early G0/G1; however, traverse of the final half of G0/G1 and commitment to DNA synthesis required the presence of Sm-C. It was found that physiological concentrations of Sm-C were required for the traverse late G1. The requirement for Sm-C for G0/G1 traverse of BALB/c-3T3 cells as opposed to human fibroblasts or glial cells may be due to a difference in endogenous synthesis of an insulin-like growth factor. Our data are in close agreement with previous reports that EGF is only required for approximately the first 8 h during traverse of the G0/G1 phase. The requirement for EGF to be present for the first 6 h of G0/G1 could result from a continued or repetitious event or by more than one distinct EGF-requiring event.