INDUCTION OF DNA-SYNTHESIS IN BALB-C 3T3 CELLS BY SERUM COMPONENTS - RE-EVALUATION OF COMMITMENT PROCESS
INDUCTION OF DNA-SYNTHESIS IN BALB-C 3T3 CELLS BY SERUM COMPONENTS - RE-EVALUATION OF COMMITMENT PROCESS
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DOI：
10.1073/pnas.74.10.4481
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发表时间：
1977-01-01
影响因子：
11.1
通讯作者：
SCHER, CD
中科院分区：
文献类型：
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作者：
PLEDGER, WJ;STILES, CD;SCHER, CD
血清中含有一种来自血小板的生长因子，也含有一种来自血小板不足的血浆的生长因子。提取物加热（100度）。C)人血小板与血小板贫乏的血浆协同作用，诱导静止、密度抑制的BALB/ C 3T3[小鼠成纤维细胞]细胞的DNA合成。单是血小板不足的血浆不能诱导DNA合成。暴露于血小板提取物的细胞能够进入细胞周期，但进入S期的速率取决于血小板缺乏血浆的浓度。诱导这种状态所需的时间是血小板提取物浓度的函数。2小时暴露在100亩。G的血小板提取物在37度。C使整个细胞群具有进入S期的能力。为4.度。或25.度。C细胞没有能力合成DNA。除去血小板提取物后，血小板提取物诱导的活性状态至少在13小时内保持稳定；在缺乏血小板贫乏的血浆的情况下，这些能态细胞不能完成细胞周期。将最佳浓度的无血小板血浆（5%）添加到这些受感细胞中，在添加血浆12小时后，细胞开始快速进入S期。添加亚理想浓度的血浆（0.25%）并没有增加细胞进入S期的速率。静止BALB/c 3T3细胞DNA合成的诱导可分为至少2个阶段，由不同的血清成分控制：能力阶段，由血小板衍生生长因子诱导；以及由血小板缺乏血浆中的因子介导的能态细胞进入细胞周期的进程。
Serum contains a growth factor derived from platelets and also growth factors derived from platelet-poor plasma. Extracts of heated (100.degree. C) human platelets function synergistically with platelet-poor plasma to induce DNA synthesis in quiescent, density-inhibited BALB/c 3T3 [mouse fibroblasts] cells. Platelet-poor plasma alone did not induce DNA synthesis. Cells exposed to platelet extracts became competent to enter the cell cycle, but the rate of entry into the S phase depended upon the concentration of platelet-poor plasma. The time required for the induction of this competent state was a function of the concentration of the platelet extract. A 2 h exposure to 100 .mu.g of the platelet extract at 37.degree. C caused the entire cell population to become competent to enter the S phase. At 4.degree. or 25.degree. C the cells did not become competent to synthesize DNA. The platelet extract-induced competent state was stable for at least 13 h after removal of the platelet extract; in the absence of platelet-poor plasma, these competent cells did not progress through the cell cycle. The addition of an optimal concentration of platelet-poor plasma (5%) to these competent cells initiated cell cycle traverse with a rapid, 1st-order entry of cells into the S phase beginning 12 h after addition of the plasma. The addition of a suboptimal concentration of the plasma (0.25%) did not increase the rate of cell entry into the S phase. The induction of DNA synthesis in quiescent BALB/c 3T3 cells can be resolved into at least 2 phases, controlled by different serum components: competence, induced by the platelet-derived growth factor; and progression of competent cells into the cell cycle, mediated by factors in platelet-poor plasma.