Common fragile sites and human cancer. A study on lymphocytes from neuroblastoma patients.

To clarify the possible relationship between fragile site expression and cancer, we examined lymphocytes from patients affected by neuroblastoma. This neoplasia may be inherited in some cases and is often characterized by a specific chromosomal aberration: deletion of the short arm of chromosome 1. We found a higher expression of fragile sites after aphidicolin and, to a lesser extent, after methotrexate treatment in lymphocytes from neuroblastoma patients as compared with those of normal donors. The analysis of fragile site distribution pointed out the increase in the expression of fragile site 1p32 in the patients. We believe that this finding might be relevant because this fragile site is located in the same region where breakpoints and rearrangements frequently occur in neuroblastoma cells.