Selective induction of interleukin-8 expression in metastatic melanoma cells by transforming growth factor-beta 1.
Selective induction of interleukin-8 expression in metastatic melanoma cells by transforming growth factor-beta 1.
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DOI：
10.1016/j.cyto.2005.03.008
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发表时间：
2005-08
期刊：
影响因子：
3.8
通讯作者：
Guo-zhen Liu;Fahao Zhang;Juwon Lee;Z. Dong
中科院分区：
文献类型：
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作者：
Guo-zhen Liu;Fahao Zhang;Juwon Lee;Z. Dong
白细胞介素(IL)-8和转化生长因子(TGF)-β1是晚期人类黑色素瘤中过度表达的促血管生成因子。我们研究了TGF-β1对表征良好的A375人黑色素瘤系统中IL-8表达的影响。我们通过酶联免疫分析和Northern blot分析证明，TGF-β1在高转移性A375SM细胞中选择性地诱导IL-8蛋白和mRNA水平的表达，而在其低转移性亲本系A375P细胞中则没有。荧光素酶报告基因构建的瞬时转染显示，TGF-β1激活了A375SM细胞中IL-8启动子的活性，而A375P细胞中没有。对进进式5 ‘缺失构建体和位点特异性突变的研究表明，包含- 133至+44个5 ’侧序列的构建体对于最大的TGF-β1诱导的转录反应是必要和充分的，TGF-β1诱导的IL-8启动子的激活依赖于该区域的AP-1（- 126至- 120bp）、NF-κB（- 94至- 71bp）和C/ ebp样因子NF- il6（- 94至- 81bp）。有趣的是，A375P和A375SM细胞均表达I型和II型TGF-β受体，TGF-β1在A375P和A375SM细胞中均诱导Smad3蛋白核易位。此外，A375P和A375SM细胞均易受TGF-β1诱导的生长抑制。因此，我们的数据表明，TGF-β1选择性地诱导高度转移的A375SM黑色素瘤细胞中IL-8的表达。TGF-β1诱导IL-8表达可能是人黑色素瘤中IL-8过表达的扩增级联反应，也是TGF-β1促进人黑色素瘤血管生成、生长和转移的潜在机制之一。
Interleukin (IL)-8 and transforming growth factor (TGF)-β1 are proangiogenic factors overexpressed in advanced human melanoma. We investigated the effects of TGF-β1 on IL-8 expression in the well-characterized A375 human melanoma system. We demonstrated by enzyme-linked immunoassay and Northern blot analysis that TGF-β1 selectively induced IL-8 expression, at both protein and mRNA levels, in highly metastatic A375SM cells but not cells of their poorly metastatic parental line A375P. Transient transfection with luciferase reporter gene constructs revealed that TGF-β1 activated IL-8 promoter activity in A375SM cells but not A375P cells. Studies with progressive 5′ deletion constructs and site-specific mutations demonstrated that a construct containing −133 to +44 of the 5′-flanking sequence was necessary and sufficient for maximal TGF-β1-induced transcription response and that TGF-β1-induced activation of IL-8 promoter depended on AP-1 (−126 to −120bp), NF-κB (−94 to −71bp), and C/EBP-like factor NF-IL6 (−94 to −81bp) in this region. Interestingly, both A375P and A375SM cells expressed type I and type II TGF-β receptors and TGF-β1 induced the nuclear translocation of Smad3 protein in both A375P and A375SM cells. Moreover, both A375P and A375SM cells were susceptible to TGF-β1-induced growth inhibition. Our data thus demonstrated that TGF-β1 selectively induced IL-8 expression in highly metastatic A375SM melanoma cells. This TGF-β1-induced IL-8 expression could be an amplification cascade responsible for overexpression of IL-8 in human melanoma and one of potential mechanisms by which TGF-β1 promotes angiogenesis, growth, and metastasis of human melanoma.