B-type oncornaviruses isolated from continuous human cancer cell Lines

Abstract

SummaryEleven lines and sublines of larynx carcinoma (HEp-2), cervical cancer (IteLa) and dedifferentiated astrocytoma (DAPT) cells were examined and viruses were isolated from eight lines. Electronmicroscopic, biophysical and biochemical examinations of the viruses showed that they belong to the B-type oneornaviruses. The virions had a size of 100 to 150 nm, they banded at densities of 1.16 to 1.17 g/ ml in sucrose gradients and t~NA from the virions contained 60--70 S component. The reproduction of the viruses was inhibited by actinomycin D, and the virions possessed reverse transcriptase (gNA-dependent DNA polymerase) activity. The isolated viruses differed antigenically from mouse mammary tumor virus.

Detection in human melanoma cell lines of particles with some properties in common with RNA tumour viruses

“…In many published studies other evidence (such as from electron microscopy) has supported the viral nature of the labelled particles, but one recent report (Narayan and Rounds, 1973) suggested that uridine-labelling in HeLa cells was associated with small (10-12 nm) ring-shaped particles. In contrast, Bykovsky et al (1973) have reported the presence in HeLa cells of a typical B-type oncornavirus. Small ring-shaped particles were present in the fluids from the melanoma cell lines but evidence from the filtration experiments strongly suggested that the uridine-labelled melanoma particles being investigated were much larger.…”

Cytology of rheumatoid synovial cells in culture. III. Significance of isolates of epithelial cell lines.

“…The occurrence of reverse transcriptase activity was not apparently related to the presence of the 'blebs' in 720301 and 710025 cells, but it is nevertheless of interest in view of the recent demonstration by Bykovsky, Miller, Yershov, Ilyin, and Zhdanov (1973) of similar activity in human cancer cell lines. In our case, however, we were unable to find morphological evidence of B-type particles in the cells.…”

Infectious DNA of tick-borne encephalitis virus

“…This system attracted our attention again after it has been shown that some clones of ttEp2 cells contained an oncornavirus (7). In the course of this study we have found that the cells chronically infected with the virus contain the viral genome transcribed into DNA and integrated into the cell nucleus, allowing therefore transfection of virus to a sensitive cell system.…”