Summary
In vitro culture of leukemic blood leukocytes from patients with chronic myelocytic leukemia (CML) showed them to be capable of division in the absence of phytohemagglutinin. In the presence of the latter, lymphocytes in the blood of these subjects were preferentially stimulated into mitosis. In the absence of the mitogenic stimulant only the immature leukemic granulocytic cells underwent division. The capacity of the leukemic leukocytes in CML to divide in vitro without an exogenous mitogenic agent was a characteristic of both Ph1-positive and Ph1-negative CML cells. The results indicate that immature granulocytic cells in the blood of patients with CML, and possibly in the blood of nonleukemic subjects, are capable of division without exogenous mitogenic substances.
Footnotes
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↵* This study has been supported in part by grant T-182 from the American Cancer Society.
Parts of this study were presented at the Annual Meeting of the American Society of Hematology, December 9, 1963, Washington, D. C., and were abstracted in Blood, 22:816–17, 1963.
- Received April 8, 1964.
- ©1964 American Association for Cancer Research.