Primate RNA Tumor Virus-Like DNA Synthesized Endogenously by RNA-Dependent DNA Polymerase in Virus-Like Particles from Fresh Human Acute Leukemic Blood Cells

Abstract

A particle of discrete biochemical composi- We also find that the DNA-synthesizing activity was recovered in a particle not disaggregated by physical manipulation (unlike the vast majority of cytoplasmic particulate material), which had a density of 1.16-1.17 g/ml.The endogenous polymerase used RNA as both template and primer for DNA synthesis. The present results stress the importance of purification of the cytoplasmic particle to obtain a suitable DNA probe. Finally, we found that virusrelated RNA can be detected in the same leukemic cells by using a DNA probe synthesized by the primate type-C sarcoma virus.

Sequences Present in Both Human Leukemic Cell Nuclear DNA and Rauscher Leukemia Virus

“…The choice of RLV in these and other studies (3)(4)(5) There are two major areas of contention in this study. The first is that the qualitative differences demonstrated in these data between normal and leukemic WBC nuclear DNA may be artifactual.…”

“…Evidence associating RNA tumor viruses with human leukemia includes: (1) possible homology between a portion of the Rauscher leukemia virus (RLV) genome and the RNA of human leukemic white blood cells (WBC) (3); (2) identification of a particulate fraction from human leukemic WBC, with the density characteristic of RNA tumor viruses, which can direct the synthesis of DNA that is partially homologous to both RLV and simian sarcoma virus (SSV) RNA (4,5); (3) [3H]DNA synthesized from RLV RNA anneals more extensively to human leukemic WBC nuclear DNA than to human normal WBC nuclear DNA (W. G. Baxt and S. Spiegelman, in preparation).…”

Systematics of RNA Tumor Viruses and Virus-Like Particles of Human Origin

“…RNA-containing viruses isolated from several species of animals, bird through primate, can The detection of viral-like components within human cells has been facilitated by the demonstration that they are located preferentially in cytoplasmic particles having density properties in common with animal type-C RNA tumor virus particles (1)(2)(3). Two viral-like molecular components, RNAdependent DNA polymerase and viral-related RNA, have been detected in this particulate fraction of human leukemic cells.…”

“…Viral-related RNA in human leukemic cells has been detected by molecular hybridization to DNA synthesized in vitro by animal type-C RNA tumor viruses (3,7). RNA-dependent DNA polymerase and viral-related RNA are present in the human particle in a functionally active form (2,3).…”

“…RNA-dependent DNA polymerase and viral-related RNA are present in the human particle in a functionally active form (2,3). This particle carries out the synthesis of DNA complementary to a portion of the viral-related RNA (2,3).…”