CYTOKINE EXPRESSION IN HUMAN PRIMARY AND METASTATIC MELANOMA-CELLS - ANALYSIS IN FRESH BIOPTIC SPECIMENS

In recent years, several studies have documented that melanoma cell li nes produce various cytokine/growth factors and their receptors. Since cell lines can acquire altered properties, such as changes in growth requirements, we studied constitutive cytokine gene expression in mela noma cells from 20 fresh surgical specimens: seven primary melanomas a nd 13 metastases (12 lymph-node metastases) and one subcutaneous metas tasis). After tumor cell isolation by discontinuous gradient, we teste d for mRNA expression by means of reverse-transcriptase polymerase cha in reaction. Most melanoma cells tested expressed growth factors: basi c fibroblast growth factor (bFGF), interleukin (IL) 1 alpha, IL-1beta, IL-6 and IL-8 and, in five cases out of 20, expressed granulocyte-mac rophage colony-stimulating factor (GM-CSF) (two out of five were also positive for GM-CSF receptor). Our results do not point to a direct co rrelation between cytokine expression and clinical stage at the time w hen the bioptic specimen was obtained. However, they allow us to sugge st a possible metastatic tumour cell phenotype, in which autogenous GM -CSF expression could modulate immune response against the tumour cell itself or could potentiate metastatic colonization properties.