Common fragile sites in chromosomes of bone marrow cells and peripheral blood lymphocytes from healthy persons and leukemia patients.

Frequency and distribution of aphidicolin-induced fragile sites (c-fra) on chromosomes of both peripheral blood lymphocytes (PBL) and bone marrow (BM) from 15 leukemia patients were studied in comparison with 22 PBL and six BM samples from healthy volunteers. In normal controls, the most frequent c-fra was 3p14 in PBL, but it was 4q21-25 in BM. The second most frequent site was 16q23 in PBL, but it was 7q11.2 in BM. These differences in fragile sites between PBL and BM may be related to distinct functions of cells in different tissues. The total number of breaks in PBL and BM showed a significant difference among individuals, but the sites were generally common. The frequency of breaks in PBL from leukemia patients was higher than in controls when the leukemic cells had any karyotypic abnormalities. In leukemia without karyotypic abnormalities and acute myeloid leukemia (AML) with (15:17), the frequency of breaks fell within normal or slightly above normal ranges. Breaks at 3p14 (22.0% of total breaks), 16q23 (7.3%), 7q32 (4.3%), Xp22 (3.7%), and 6q26 (2.9%) were frequent in PBL from seven AML patients. Breaks at 4q21-25 (2.1%), 7q22 (2.2%), 7q32, and Xp22 were more frequently induced than in controls, and 1p32 (0.1%), 3p14, 6q26, and 16q23 were less often expressed than in controls. On the other hand, PBL from acute lymphoblastic leukemia patients showed a higher frequency of breaks only at 1p22 (3.4%) and the frequency of breaks at 3p14 (30.2%) decreased (p less than 0.05). The PBL from AML patients with t(8;21) (q22;q22) showed breaks at 8q22 and 8q24, and the frequencies were significantly higher than those of other types of leukemia or in controls (p less than 0.001). The results of this study suggest that fragility of chromosomes may be related to the chromosomal rearrangement in or predisposition to leukemia.