A LOW NM23.H1 GENE-EXPRESSION IDENTIFYING HIGH MALIGNANCY HUMAN MELANOMAS

The NM23 gene has been proposed as a metastasis-suppressor gene, and i ts use has been suggested as prognostic factor. NM23 was identified in a system of murine melanoma cell lines, in which an inverse relations hip was found between NM23 expression and metastatic ability. In a hum an malignant melanoma study NM23 expression was found to be significan tly lower in metastases that developed less than 24 months after diagn osis of the primary tumours. The present paper studies the expression of the NM23.H1 gene in cell lines which derive from primary or metasta tic human malignant melanomas in relation to staging, infiltration deg ree, lymphocytic infiltration, cell morphology, cell pigmentation, kar yotype, and disease-free survival. The level of mRNA expression of the NM23 gene is significantly lower in cell lines that derive from more infiltrating primary melanomas than in cell lines obtained from less i nfiltrating tumours. Moreover, cell lines derived from tumours of pati ents with a disease-free survival of more than 24 months (24-58 months ) express the NM23 gene at higher levels than cell lines obtained from melanomas of patients with a disease-free survival of less than 24 mo nths (6-15 months).