Deletion of chromosome 2 is an early event in the development of radiation-induced myeloid leukemia in SJL/J mice.
In this study we have analyzed the chromosomal changes in the preleukemic phase in SJL/J mice treated with radiation and acute myeloid leukemias (AMLs) induced by radiation alone or with additional corticosteroid treatment. SJL/J mice exposed to 300 rad whole body irradiation developed a low incidence of AML (20-25%) that could be markedly increased (to 50-70%) by additional coleukemogenic treatment with corticosteroids. Partial deletion in one chromosome 2 was found in 100% of bone marrow and spleen cells of leukemic animals in both treatment modalities, whereas the age-matched controls exhibited a normal karyotype. Five types of deletion were observed according to site and size, but region D through G was the common missing part in all five types of chromosome 2 deletion. The occurrence of chromosome 2 deletion was also tested among bone marrow cells removed from 17 mice, 4 months after exposure to 300 rad whole body irradiation, long before the time when AML development is expected. About 80% of the mice tested had different levels of deleted chromosome 2 among their bone marrow population. Cytological and histological examination of bone marrow and spleen of most tested animals showed a normal hematologic picture. These results suggest that the marker chromosome is related to the process of radiation-induced initiation of AML in SJL/J mice.
Trakhtenbrot
L
L
Department of Chemical Immunology, Weizmann Institute of Science, Rehovot, Israel.
Krauthgamer
R
R
Resnitzky
P
P
Haran-Ghera
N
N
D000818:Animals; D001853:Bone Marrow / Q000648:ultrastructure; D002872:Chromosome Deletion; D005260:Female; D015470:Leukemia, Myeloid, Acute / Q000235:genetics*; D007953:Leukemia, Radiation-Induced / Q000209:etiology / Q000235:genetics*; D051379:Mice; D008815:Mice, Inbred Strains; D011519:Proto-Oncogenes