Consistent karyotypic abnormalities in human malignant melanomas.

Cytogenetic analysis performed on 11 human malignant melanoma cell lines that were passaged through nude mice revealed both numerical and structural types of chromosomal defects. Banding analysis showed structural anomalies in chromosomes 1, 3, 5, 6, 7, 9, 10, 11, 14 and 15. Of these, the most frequently involved chromosomes were 6, 7, and 9. Chromosomes 3 and 11 were next with chromosomes 5 and 10, the least involved. Our results were very similar to results published in the literature on melanoma cytogenetics except that we found additional chromosomal alterations. Most frequently involved structural anomalies of the short arm of chromosome 9 and the long arm of chromosome 6 have been interpreted as primary and secondary defects, respectively, in melanocyte oncogenesis.