Di Francesco P, Favalli C, Liboi E
Department of Experimental Medicine and Biochemical Sciences, 2nd University of Rome, Tor Vergata, Italy.
Cell Biol Int Rep. 1988 May;12(5):365-72. doi: 10.1016/0309-1651(88)90061-6.
Most growth active hormones and peptides are mitogenic only in the presence of other growth factors [e.g., Platelet Derived Growth Factor (PDGF) and Epidermal Growth Factor (EGF) in "competence-progression" fibroblast model]. We have previously described that EGF alone is able to induce the signals which appear necessary for the mitogenic stimulation of EL2 rat embryo fibroblast line. Recently, we have demonstrated that Transforming Growth Factor beta (TGF beta) slightly stimulates the mitogenic response in EL2 cells. Here, we show that in EGF-treated EL2 cells the induction of at least four inducible-secreted proteins (ISPs, range from 29,000 to 68,000 Mr) is accompanied by a marked increase in DNA synthesis. In contrast, TGF beta or different concentrations of EGF induce a slow increase of the ISPs proportional to slow induction in DNA synthesis. Our results suggest that the mitogenic response in EL2 cell line may be connected with the qualitative and quantitative induction of these secreted proteins.
大多数生长活性激素和肽只有在其他生长因子存在的情况下才具有促有丝分裂作用[例如，在“能力-进展”成纤维细胞模型中的血小板衍生生长因子（PDGF）和表皮生长因子（EGF）]。我们之前曾描述过，单独的EGF能够诱导出对于EL2大鼠胚胎成纤维细胞系有丝分裂刺激似乎必不可少的信号。最近，我们证明了转化生长因子β（TGFβ）能轻微刺激EL2细胞中的有丝分裂反应。在此，我们表明，在经EGF处理的EL2细胞中，至少四种诱导性分泌蛋白（ISPs，分子量范围为29,000至68,000）的诱导伴随着DNA合成的显著增加。相比之下，TGFβ或不同浓度的EGF诱导ISPs缓慢增加，这与DNA合成的缓慢诱导成比例。我们的结果表明，EL2细胞系中的有丝分裂反应可能与这些分泌蛋白的定性和定量诱导有关。
