Expression of retrovirus-related functions in the methylcholanthrene-induced rat myelogenous leukemia
Keszeghová, V.; Veselovská, Z.; Hlavayová, E.; Svec, J.
Neoplasma 32(5): 581-591
1985
ISSN/ISBN: 0028-2685 PMID: 2415837 Document Number: 260666
The rat MR-leukemia (MR-Le) induced in Wistar rats by methylcholanthrene and whole-body irradiation, has been shown to be transmitted by means of cell-free filtrates of spleen and liver extracts. These earlier results lead us to determine the expression of retroviral functions by MR-Le myeloblasts in vivo and in vitro. DNA polymerase activity associated with particulate material purified from plasma of rats carrying MR-Le and from MR-Le tissue culture fluid, increased with the number of MR-Le myeloblasts. Interspecies-specific antigenic determinants, common to some mammalian retroviruses, are expressed on the surface of MR-Le cells. Electrophoretic pattern of the MR-Le viral material purified from leukemic plasma and tissue culture fluid revealed the presence of polypeptides with molecular weights related to proteins of mammalian retroviruses which were not identical with main structural proteins of the endogenous rat C-type helper virus (RaLV). The results strongly support the proposition that RaLV-unrelated rat retrovirus is involved in the onset of MR-Le.