Identification of a Recurring Translocation Site Involving Chromosome 6 in Human Malignant Melanoma

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 6ql 1-13, 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 masl. 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.