DOWN-REGULATION OF THE NOVEL GENE MELASTATIN CORRELATES WITH POTENTIAL FOR MELANOMA METASTASIS

We have used differential cDNA display to search for genes whose expre ssion correlates with an aggressive phenotype in variants of the B16 m urine melanoma line, B16-F1 and B16-F10, This analysis identified a no vel gene, termed melastatin, that is expressed at high levels in poorl y metastatic variants of B16 melanoma and at much reduced levels in hi ghly metastatic B16 variants, Melastatin was also found to be differen tially expressed in tissue sections of human melanocytic neoplasms, Be nign nevi express high levels of melastatin, whereas primary melanomas showed variable melastatin expression, Melastatin transcripts were no t detected in melanoma metastases. Within the set of human primary cut aneous melanomas examined, melastatin expression appeared to correlate inversely with tumor thickness, The expression pattern observed sugge sts that loss of melastatin expression is an indicator of melanoma agg ressiveness.