Notwithstanding the well-characterised roles of a number of oncogenes in neoplastic transformation, microRNAs (miRNAs) are increasingly implicated in several human cancers. Discovery of miRNAs in several oncogenic herpesviruses such as KSHV has further highlighted the potential of virus-encoded miRNAs to contribute to their oncogenic capabilities. Nevertheless, despite the identification of sev...

A rapid and simple technique for the detection of latent RNA tumor viruses has been described. It is based on phenotypic mixing between the latent agent (s) and a nondefective strain of RSV used as indicator virus. Most of the embryos from two different chicken lines tested so far contain such agents. According to their host range and serological properties they belong to subgroup E. The phenot...

It therefore appears that the expression of certain viral functions is dependent upon the physiological state of the cell at the time of infection. That the effect of a tumor virus on its host cell depends upon the operation of certain cellular functions has been previously shown by Temin'1 and Bader"2 for the RNA-containing Rous tumor virus. Summary.-A combined study by radioautography and imm...

Type-C RNA tumor virus particles were released from three different human lymphoblastoid cell lines after incubation in arginine-deficient medium. The released virus-like particles were characterized by (a) their ability to band in sucrose gradients at a density of 1.16-1.18 g/ml; (b) the presence of an RNA-directed DNA polymerase activity resembling that of the oncornaviruses; and (c) isolatio...

The 60-70S RNAs of several transforming and nontransforming avian tumor viruses have different electrophoretic mobilities. The RNA of transforming viruses contains two electrophoretically separable subunit classes: a and b. The relative concentrations of these subunits vary with the virus strain. Avian leukosis viruses and nontransforming derivatives of a sarcoma virus lack subunits of class a....

The orphan parvovirus tumor virus X (TVX) has potent oncolytic activity. Compared to other viruses from the species Rodent protoparvovirus 1, TVX has a 111 nucleotide deletion in its nonstructural (NS) gene, a 24 nucleotide insertion in VP1, and a 93 nucleotide repeat initiating from the C-terminus of the capsid gene.