Induction of Growth and Differentiation in Hematopoietic Cells by Oncogene-Containing Leukemia Viruses

Abstract

Defective avian leukemia viruses are oncogene-containing retroviruses that induce both hematopoietic neoplasms in vivo and the proliferation of hematopoietic cells in vitro. We have been particularly interested in several strains containing the nuclear oncogenes v-myb or v-myb, either alone or in combination with a second oncogene. All four v-myc-containing strains transform cells with the phenotype of macrophages. However, while three viruses containing v-myc only transform macrophages that are dependent on chicken myelomonocytic growth factor (cMGF [3], the MH2 strain transforms macrophages that produce their own cMGF and that grow in an autocrine fashion [2, 5]. We have shown that v-mil,the second oncogene present in MH2, is responsible for this effect and that a number of tyrosine kinase-type oncogenes as well as v-Haras are likewise capable of inducing cMGF production.