A specific chromosomal deletion in murine leukemic cells induced by radiation with different qualities.
G-banded metaphase chromosomes prepared from 14 male CBA/Ca mice with histologically confirmed myeloid leukemia (ML) were studied in an effort to identify specific chromosomal changes associated with radiation leukemogenesis. The chromosome studies were undertaken as part of a larger investigation of radiation carcinogenesis, in which mice were exposed to radiation of several different qualities, i.e., x-rays, gamma-rays and "monoenergetic" fast neutrons of 5 mean energies ranging from 0.2 to 14 MeV. The 14 ML cases showed no histologically phenotypic differences and they were transplantable in syngeneic mice. We detected a specific chromosomal deletion in 1 copy of mouse chromosome 2 at regions D-E in all radiation-induced ML cells, regardless of radiation quality. Our results strongly implicate the involvement of genes within or close to regions D-E of chromosome 2 in radiation leukemogenesis. In addition to the specific deletion in chromosome 2, loss or gain of the Y chromosome was also detected in some cells from 6 ML cases. Because this hypo- or hyperploidy occurred in only a small fraction of leukemic cells, a causative role in radiation leukemogenesis appears unlikely.
Rithidech
K N
KN
Medical Department, Brookhaven National Laboratory, Upton, NY 11973.
Bond
V P
VP
Cronkite
E P
EP
Thompson
M H
MH
D000818:Animals; D002872:Chromosome Deletion; D002875:Chromosomes / Q000528:radiation effects*; D004307:Dose-Response Relationship, Radiation; D005720:Gamma Rays; D007951:Leukemia, Myeloid / Q000235:genetics* / Q000473:pathology*; D008297:Male; D051379:Mice; D008808:Mice, Inbred CBA; D009502:Neutrons; D010641:Phenotype; D011003:Ploidies; D014965:X-Rays