SURVIVAL OF CELLS WITH BLEOMYCIN-INDUCED CHROMOSOMAL LESIONS IN THE CULTURED LYMPHOCYTES OF LUNG-CANCER PATIENTS

In a previous study of lung cancer, we showed that bleomycin, a radiom imetic agent, induced breaks preferentially on chromosomes 4 and 5. Th e molecular cytogenetic study reported here, using chromosome painting and G banding, was designed to assess whether the chromatid breaks in duced by bleomycin could survive as chromosome-type aberrations after treated lymphocyte populations were allowed to recover in a drug-free medium for one or two cell generations and whether the survival rates of lesions on chromosomes 4 and 5 differed in cases with lung cancer a nd controls, The findings from 16 cases and 14 controls showed that in samples allowed to recover for 48 h, most aberrations were of the chr omosome type, The proportion of chromosome 5 abnormalities surviving a s chromosome-type aberrations was significantly higher in the cells of lung cancer cases (13.4%) than in controls (4.6%; P < 0.0001), Howeve r, no significant differences in survival of chromosome 4 abnormalitie s were detected between cases and controls, The proportions of chromos ome 5q13-q22 abnormalities were 5.3% in the cases and 0.6% in the cont rols (P < 0.0001), 5q13-q22 regions encompassed 38.4% of all abnormali ties on chromosome 5 in the cases but only 14.5% in the controls. Ther efore, the survival rate of chromosome 5 lesions (especially those at 5q13-q22) in lymphocytes might be used as a biomarker to identify popu lations at high risk for lung cancer.