Induction of Mouse Leukæmia with Purified Nucleic Acid Preparations

Abstract

RECENT studies by Gross¹ and others^2,3 have shown that leukæmia with immunogenetic characteristics of the recipient strain can be induced in certain low-leukæmia-incidence strains of mice by injecting into newborn animals cell-free extracts of tissues of certain high-leukæmia strains. Although the active leukæmogenic agent has been referred to as a virus, direct evidence on this point has been lacking. At present it can be said only that the agent is filtrable and thermolabile, and is transmitted in certain families of mice from one generation to another directly through the embryos. Under certain poorly defined conditions, cell-free extracts of leukæmic organs may also produce parotid gland tumours, sarcomas and perhaps other neoplasms, indicating that the active agent is either multipotent or that extracts contain several oncogenic agents.