Enhanced expression of 1p32 and 1p22 fragile sites in lymphocytes in cutaneous malignant melanomas.

Frequency and distribution of 5-fluorodeoxyuridine (5-FdU) plus caffeine-induced fragile sites on chromosomes of peripheral blood lymphocytes (PBL) from 10 patients with cutaneous melanoma were studied in comparison with 10 PBL samples from normal donors of corresponding sex and age. The total number of breaks showed a significant difference among individuals in both groups, however, the average frequencies of 5-FdU plus caffeine-induced, as well as spontaneous damages in PBL from melanoma patients, were higher than those from healthy volunteers. The analysis of the breakpoint distribution showed a statistically significant increase in the expression of several fragile sites. The highest enhancement was observed at 1p32 and 1p22 sites (p less than 0.001). Earlier, the increase in the expression of 1p32 fragile sites was reported for neuroblastoma patients. We believe that enhanced expression of fragile sites in 1p may play a yet-unknown pathogenetic role in the development of some neuroectodermal tumors.