The expression frequency of common fragile sites and genetic predisposition to colon cancer

The expression frequency of common fragile sites induced by aphidicolin (Ap c), bromodeoxyuridine (BrdU), and caffeine was evaluated on prometaphase ch romosomes obtained from the peripheral blood lymphocytes of 32 patients wit h colon cancer, 30 of their clinically healthy family members and 30 age-ma tched normal controls. The proportion of-damaged cells (P < 0.001), the mea n number of chromosomal aberrations and the expression frequencies of fragi le sites were significantly higher in the patient and relative groups compa red to the control group. Our findings show an increased genetic instabilit y in patients with colon cancer and their first-degree relatives. In additi on, common fragile sites can be used as a suitable marker for determining g enetic predisposition to cancer. (C) 2000 Elsevier Science Inc. All rights reserved.