The recognition of recurring sites of chromosome change in human cancers has pinpointed the location in the genome of several important growth-regulatory sequences (e.g., cellular oncogenes). This report details the finding of a recurring translocation site involving the long arm of chromosome 6 (6q) in malignant melanoma. We have observed a translocation (t) between chromosomes 1 and 6 in five different cases of malignant metastatic melanoma. All five melanomas evidencing t(1;6) involved band regions 6q11-13, while two different regions of chromosome 1 (p22, q12–q21) were shown to be translocated to 6q. In reviewing previously published cases of melanoma, an additional two cases of t(1;6) and 13 cases of other translocations to 6q11-13 have been identified. Chromosome 6q contains several biologically important gene sequences including the proto-oncogenes ros, myb, and mas1. However, based on current mapping studies, the breakpoint of this translocation (6q11–13) is not within the region encoding these sequences. By analogy to other systems,molecular analysis of the translocation breakpoints may identify a gene(s) which plays a role in melanoma tumorigenesis.
Research supported in part by USPHS Grants CA-29476 (J. M. T.) and CA-41183 (J. T. M., F. L. M.) awarded by the National Cancer Institute.