RNATumor Viruses

Abstract

OverviewRetroviruses are enveloped viruses that contain a diploid RNA genome and are defined by the presence of reverse transcriptase, a DNA polymerase that transcribes RNA into DNA, which is then inserted into the host cell chromosome. These processes often lead to the capture and/or alteration of genetic material and the transfer of information between cells, with neoplastic transformation of the infected cell being an occasional outcome of infection. Retroviruses are also associated with immunodeficiencies and with neurologic diseases, although infection is often asymptomatic. Retroviruses can also enter the germ line and be present as a part of the genetic complement of all members of a species. These viruses are called endogenous retroviruses. Although most retroviral malignancies occur as leukemia/lymphomas in nonhuman species, human T‐cell leukemia virus type I (HTLV‐I) causes adult T‐cell leukemia/lymphoma in a minority of infected humans, as well as a neurologic disease and a variety of other pathologies. Human immunodeficiency virus type 1 (HIV‐1), although not considered a tumor virus, is associated with an increased incidence of several types of tumors, especially those caused by viruses such as human papillomavirus and Epstein–Barr virus.