EXPRESSION OF CYTOKINE GROWTH FACTORS AND THEIR RECEPTORS IN HUMAN-MELANOMA AND MELANOCYTES/

Human tumors can constitutively express cytokines and growth factors, but the extent of this expression has not been investigated. Using 44 different probes to cytokines, growth factors, and their receptors, we tested 21 melanoma and 5 melanocyte cultures for RNA transcript expre ssion by reverse transcriptase-polymerase chain reaction. With 30 ampl ification cycles, expression fo the cytokines interleukin (IL)-1 beta, IL-6, leukemia inhibitory factor (LIF), IL-7, gro alpha, IL-8 and the p35 chain of IL-12 was detected in more than 60% of melanomas. Concom itant receptors for IL-6 and IL-7 were also detected. IL-1 alpha, IL-5 , Rantes, IL-10, interferon (IFN)-beta, tumor-necrosis factor (TNF)-al pha, G-colony-stimulating factor (CSF) and GM-CSF were expressed at lo wer levels. Melanocytes showed greatly reduced cytokine RNA transcript s, and only gro alpha was consistently detected. No expression of IL-2 , IL-3, IL-4, IL-9, the p40 chain of IL-12, IFN-alpha or IFN-gamma RNA transcripts was detected in melanomas or melanocytes. The growth fact ors expressed by melanomas and, after further signal amplification, by melanocytes were transforming growth factor (TGF)-alpha, epidermal gr owth factor (EGF), TGF-beta, endothelial-cell growth factor (ECGF), ba sic-fibroblast growth factor (bFGF), nerve growth factor (NGF) and ste el. The receptors EGFR, FGFR, NGFRp70 and c-kit were also expressed by melanomas and melanocytes. These results point to new possible autocr ine and paracrine pathways in melanoma biology. (C) 1994 Wiley-Liss, I nc.