SENSITIVITY TO BLEOMYCIN AND ARABINOSIDE CYTOSINE IN LYMPHOCYTES OF PATIENTS AFFECTED BY NEUROBLASTOMA AND IN THOSE OF THEIR PARENTS

Chromosomal instability has been described in patients affected by var ious tumors. We previously reported a high sensitivity to fragile site s induction by aphidicolin in lymphocytes from patients affected by ne uroblastoma and in those from their parents. In the search for the mos t suitable clastogenic agent to enhance the possible differences betwe en healthy controls and patients affected by tumors, we have now teste d two otherdrugs: bleomycin, a radiomimetic agent already used in vitr o on chromosomes of patients affected by other tumors and arabinoside cytosine, an inhibitor of DNA polymerases alfa and beta. We observed a high sensitivity to bleomycin both in patients and in their parents, but to arabinoside cytosine only in NB patients. Moreover, the two dru gs induced more fragile sites in 1p in patients and in their parents t han in healthy controls. This phenomenon, which we already observed af ter treatment with aphidicolin, might be related to the frequent delet ions and loss of heterozigosity in 1p in neuroblastoma cells.