摘要
本实验探讨了生长因子和胞质微管在刺激G_0期C3H/10 T1/2细胞进入S期合成DNA中的作用及其相互关系。结果表明,PPP(pla- telet-poor plasma)不具有刺激DNA合成的能力,浓度在30ng/ml以上的EGF仅能刺激部分G_0期细胞进入S期,而50ng/ml EGF与5%PPP共同作用时,则表现出它们间具有较强的协同剌激作用,其刺激DNA合成的效果基本上达到与10%血清相同。Taxol可抑制微管的解聚,G_0期细胞经其处理后,使微管处于稳定状态时能明显抑制血清或EGF+PPP对细胞合成DNA的刺激作用。这种抑制作用在G_0期细胞进入S期的早期阶段即表现出来,说明只有生长因子的刺激作用而无微管的解聚,细胞便不能从G_0期进入S期。G_0期细胞经秋水仙酰胺处理使微管解聚后,则能提高血清或EGF+PPP对DNA合成的刺激作用。同样地,这种刺激作用也在G_0期细胞进入S期的早期阶段即表现出来。但秋水仙酰胺单独处理G_0期细胞,虽使微管处于解聚状态,若无生长因子存在,则无刺激作用,G_0期细胞便不能进入S期。因此,生长因子之间的协同刺激作用和微管的解聚是G_0期C3H/10 T1/2细胞进入S期进行DNA合成的两个必要条件。
PPP (platelet-poor plasma) alone can not stimulate DNA synthesis in Go C3H/10T1/2 cells. 50ng/ml of EGF promoted partial Go cells to enter S phase. However, there was an apparent synergetic effect of simultaneous treatment with 50 ng/ml EGF and 5%PPP, their synergetic effect to stimulate DNA synthesis in Go cells was the same as 10% calf serum.Taxol can resist the depolymerization of microtubules. After treatment with taxol (10μmol/L), the progression from Go to S phase in C 3 H 10 T 1/2 cells was inhibited. This inhibition was especially exhibited at early stage of transition from Go to S phase. The result indicated that Go cells can not enter S phase without the depolymerization of microtubules. It showed that DNA synthesis was stimulated by the simultaneous treatment with colcemid (0.1μ.g/ml) and growth factors (50 ng/ml EGF+5%PPP or 10% Calf serum). But without the stimulation of growth factors, the unique effect of depolymcrization of microtubules can not stimulate DNA synthesis. The results present evidence indicating that the depolymerization of microtubules has the potency to elevate DNA synthesis in Go cells stimulated by growth factors. This potency was also appeared at early stage of progression from Go to S phase.We suggest that the depolymerization of cytoplasmic microtubules and synergetic effect of growth factors are involved in account for the transition from Go to S phase in C 3 H 10 T 1/2 cells.
出处
《实验生物学报》
CSCD
1990年第4期431-439,共9页
Acta Biologiae Experimentalis Sinica
基金
国家自然科学基金
关键词
生长因子
胞质微管
DNA合成
Growth factors. Cytoplasmic microtubules. DNA synthesis Acknowledgments
