These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


PUBMED FOR HANDHELDS

Search MEDLINE/PubMed


  • Title: Selective induction of interleukin-8 expression in metastatic melanoma cells by transforming growth factor-beta 1.
    Author: Liu G, Zhang F, Lee J, Dong Z.
    Journal: Cytokine; 2005 Aug 07; 31(3):241-9. PubMed ID: 15975819.
    Abstract:
    Interleukin (IL)-8 and transforming growth factor (TGF)-beta1 are proangiogenic factors overexpressed in advanced human melanoma. We investigated the effects of TGF-beta1 on IL-8 expression in the well-characterized A375 human melanoma system. We demonstrated by enzyme-linked immunoassay and Northern blot analysis that TGF-beta1 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-beta1 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-beta1-induced transcription response and that TGF-beta1-induced activation of IL-8 promoter depended on AP-1 (-126 to -120 bp), NF-kappaB (-94 to -71 bp), and C/EBP-like factor NF-IL6 (-94 to -81 bp) in this region. Interestingly, both A375P and A375SM cells expressed type I and type II TGF-beta receptors and TGF-beta1 induced the nuclear translocation of Smad3 protein in both A375P and A375SM cells. Moreover, both A375P and A375SM cells were susceptible to TGF-beta1-induced growth inhibition. Our data thus demonstrated that TGF-beta1 selectively induced IL-8 expression in highly metastatic A375SM melanoma cells. This TGF-beta1-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-beta1 promotes angiogenesis, growth, and metastasis of human melanoma.
    [Abstract] [Full Text] [Related] [New Search]