Constitutive expression of multiple growth factor genes by melanoma cells but not normal melanocytes

J Invest Dermatol. 1991 Jul;97(1):20-6. doi: 10.1111/1523-1747.ep12477822.


In a panel of metastatic melanoma cell lines we found steady-state mRNA transcripts for multiple growth factors including basic fibroblast growth factor (bFGF), platelet-derived growth factor (PDGF)-A, PDGF-B, transforming growth factor (TGF)- beta 1, TGF- alpha, melanoma growth-stimulating activity (MGSA), interleukin (IL)-1 alpha, and IL-1 beta but not insulin-like growth factor (IGF)-1 or IGF-2. Expression of growth factor genes was constitutive because prior to RNA extraction melanoma cells were maintained in a chemically defined culture medium free of exogenous growth factors. Each of four cell lines had an individual pattern of expression of either two, four, five, or seven growth factors; however, all cell lines shared expression of the bFGF gene. Two strains of normal melanocytes expressed TGF- beta 1 but not bFGF, PDGF, TGF- alpha , or MGSA mRNA at detectable levels. We tested growth-modulatory effects of the growth factors most frequently expressed by melanoma cells (bFGF, TGF- alpha, TGF- beta, PDGF). None of these stimulated melanoma cell growth consistently, whereas exogenous, acid-activated TGF- beta inhibited melanoma growth at concentrations greater than 10 ng/ml, suggesting that bioactive TGF- beta may represent a physiologic growth inhibitor. Neither neutralizing antisera to PDGF or TGF- alpha nor a monoclonal antibody to the epidermal growth factor (EGF)-receptor inhibited melanoma cell growth. Our results indicate that multiple growth factors are expressed simultaneously and constitutively by melanoma cells but not normal melanocytes in culture. Expression of bFGF is a common feature underscoring the significance of bFGF as an autocrine factor for melanoma cells as described earlier. Secreted PDGF and TGF- alpha are apparently not involved in or not essential for autocrine growth stimulation of melanoma cells.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Blotting, Northern
  • ErbB Receptors / genetics
  • ErbB Receptors / immunology
  • Gene Expression*
  • Growth Substances / genetics*
  • Humans
  • Interleukin-1 / genetics
  • Melanocytes / metabolism*
  • Melanoma / metabolism*
  • Melanoma / pathology
  • Platelet-Derived Growth Factor / genetics
  • Platelet-Derived Growth Factor / immunology
  • RNA, Messenger / analysis
  • Transforming Growth Factors / genetics
  • Transforming Growth Factors / immunology
  • Transforming Growth Factors / pharmacology
  • Tumor Cells, Cultured


  • Growth Substances
  • Interleukin-1
  • Platelet-Derived Growth Factor
  • RNA, Messenger
  • Transforming Growth Factors
  • ErbB Receptors