Joshi-Barve S S, Rangnekar V V, Sells S F, Rangnekar V M
Department of Surgery, University of Kentucky, Lexington 40536.
J Biol Chem. 1993 Aug 25;268(24):18018-29.
Interleukin-1 (IL-1) induces programmed growth arrest in human melanoma cells, A375-C6. IL-1 action in these cells is associated with induction of a cell type-specific immediate-early (IE) gene expression program characterized by strong, rapid, and sustained induction of gro-alpha and gro-beta, but transient induction of c-jun, IRG-9, and NAK-1, and lack of induction of c-myc. With the exception of gro-alpha and gro-beta, these IE genes are also associated with growth-stimulatory responses in the melanoma cells, suggesting that the gro-genes may play key roles in the growth arrest action of the cytokine. To elucidate the early intracellular signals associated with IL-1 action, we are studying the second messenger signals and transcription factors required for induction of gro-genes. Here, we present evidence that IL-1-inducible gro-gene expression is dependent on tyrosine kinase signaling. Using gel retardation and transient expression assays, we show that IL-1 causes protein tyrosine phosphorylation-dependent activation of NF-kappa B enhancer binding protein, which then induces transcription of the gro-genes via an NF-kappa B site located 76 base pairs upstream from the cap site. IL-1-activated protein tyrosine phosphorylation is also required for gro-gene induction in human cervical carcinoma cells, HeLa; human fibroblast cells, WI-38; and mouse fibroblast cells, L929. Thus, in diverse cell types, IL-1 induces gro-genes via tyrosine kinase-dependent signals.
白细胞介素-1(IL-1)可诱导人黑色素瘤细胞A375-C6发生程序性生长停滞。IL-1在这些细胞中的作用与一种细胞类型特异性的早期即刻(IE)基因表达程序的诱导相关,该程序的特征为强烈、快速且持续地诱导gro-α和gro-β,但短暂诱导c-jun、IRG-9和NAK-1,且不诱导c-myc。除gro-α和gro-β外,这些IE基因也与黑色素瘤细胞中的生长刺激反应相关,这表明gro基因可能在细胞因子的生长停滞作用中发挥关键作用。为了阐明与IL-1作用相关的早期细胞内信号,我们正在研究诱导gro基因所需的第二信使信号和转录因子。在此,我们提供证据表明IL-1诱导的gro基因表达依赖于酪氨酸激酶信号传导。通过凝胶阻滞和瞬时表达分析,我们表明IL-1导致蛋白酪氨酸磷酸化依赖性激活NF-κB增强子结合蛋白,然后该蛋白通过位于帽位点上游76个碱基对处的NF-κB位点诱导gro基因的转录。IL-1激活的蛋白酪氨酸磷酸化在人子宫颈癌细胞HeLa、人成纤维细胞WI-38和小鼠成纤维细胞L929中诱导gro基因时也是必需的。因此,在多种细胞类型中,IL-1通过酪氨酸激酶依赖性信号诱导gro基因。