Technical Report No. 22-85
Proliferation, differentiation, and possible radiation-induced chromosome abnormalities in circulating hemopoietic stem cells
Amenomori T, Honda T, Matsuo T, Otake M, Hazama R, Tomonaga Y, Tomonaga M, Ichimaru MEditor’s note: A publication based on this report was published in Exp Hematol 16:849-54, 1988.
Summary
The effects of atomic bomb radiation on hemopoietic stem cells were studied cytogenetically and from the aspect of differentiation and proliferation, using single colonies derived from human hemopoietic stem cells. The subjects studied were A-bomb survivors in the high dose exposure group (T65D 100+ rad) with a high incidence (10% or more) of radiation-induced chromosome abnormalities in their peripheral lymphocytes, and their controls. Examinations were performed on 21 A-bomb survivors (10 males and 11 females) and 11 controls (5 males and 6 females).
Colony formation of hemopoietic stem cells (granulocyte/monocyte-colony-forming cells, GM-CFC and burst-forming unit-erythrocytes, BFU-E) was made by the methylcellulose method patterned after the methods of Iscove et al and Ogawa et al using 5-10 ml of peripheral blood. Chromosome specimens were prepared from single colonies by the micromethod which we have reported elsewhere.
The total number of colonies analyzed in the exposed group was 131 GM-CFC and 75 BFU-E. Chromosome abnormalities were observed in 15 (11.5%) and 9 (12.0%) colonies, respectively. In the control group, the total number of colonies analyzed was 61 GM-CFC and 41 BFU-E, but none of the colonies showed chromosome abnormalities. A highly significant difference in chromosome abnormalities was demonstrated by an exact test with a probability of 0.3% for GM-CFC and 1.7% for BFU-E. The karyotypes of chromosome abnormalities obtained from the colonies of hemopoietic stem cells in the exposed group were mostly translocations, but deletion and maker chromosomes were also observed. In two individuals, such karyotypic abnormalities as observed in the peripheral lymphocytes were seen also in the hemopoietic precursor cells. This finding suggests that radiation may produce an effect even on relatively undifferentiated hemopoietic stem cells.
The effects of atomic bomb radiation on hemopoietic stem cells were studied cytogenetically and from the aspect of differentiation and proliferation, using single colonies derived from human hemopoietic stem cells. The subjects studied were A-bomb survivors in the high dose exposure group (T65D 100+ rad) with a high incidence (10% or more) of radiation-induced chromosome abnormalities in their peripheral lymphocytes, and their controls. Examinations were performed on 21 A-bomb survivors (10 males and 11 females) and 11 controls (5 males and 6 females).
Colony formation of hemopoietic stem cells (granulocyte/monocyte-colony-forming cells, GM-CFC and burst-forming unit-erythrocytes, BFU-E) was made by the methylcellulose method patterned after the methods of Iscove et al and Ogawa et al using 5-10 ml of peripheral blood. Chromosome specimens were prepared from single colonies by the micromethod which we have reported elsewhere.
The total number of colonies analyzed in the exposed group was 131 GM-CFC and 75 BFU-E. Chromosome abnormalities were observed in 15 (11.5%) and 9 (12.0%) colonies, respectively. In the control group, the total number of colonies analyzed was 61 GM-CFC and 41 BFU-E, but none of the colonies showed chromosome abnormalities. A highly significant difference in chromosome abnormalities was demonstrated by an exact test with a probability of 0.3% for GM-CFC and 1.7% for BFU-E. The karyotypes of chromosome abnormalities obtained from the colonies of hemopoietic stem cells in the exposed group were mostly translocations, but deletion and maker chromosomes were also observed. In two individuals, such karyotypic abnormalities as observed in the peripheral lymphocytes were seen also in the hemopoietic precursor cells. This finding suggests that radiation may produce an effect even on relatively undifferentiated hemopoietic stem cells.