Spontaneous and Induced Preleukemia Cells in C57BL/6 Mice: Brief Communication2

Abstract

A transplantation bioassay method was used to verify the presence of preleukemla cells in C57BL/6 mice shortly after leukemogenic treatment or in relation to age increase. Preleukemla cells were identified mainly among bone marrow cells of old C57BL/6 mice or within 10 to 30 days after leukemogenic treatment of young mice with radiation-induced leukemia virus variants, fractionated doses of irradiation, or 7,12-dimethylbenz[ a]anthracene (DMBA), although the overt disease did not occur until many months later. Mice could carry preleukemla cells without necessarily developing overt leukemia. Since the leukemogenic agents used in the present studies induced T-leukemias, the role of the thymus in the induction of preleukemla cells was tested. Thymectomy affected viral transformation but did not diminish the number of preleukemla cells induced by DMBA or X-ray.