Oncogenic Dna and Rna Viruses Causing the Cancer Pathogenesis

The present paper explore out the better-characterized and most intensively studied oncogenic viruses of humans and animals. Many DNA and RNA viruses have been proved to be oncogenic (or carcinogenic) in a variety of animals, ranging from amphibia to primates, and évidence grows stronger that certain forms of human cancer are of viral origin. Several DNA viruses have been associated with the causation of cancer in animals. Adenoviruses cause tumours in laboratory animals, while bovine papillomavirsues cause both types of tumours (neoplasm), i.e., benign neoplasm as well as malignant neoplasm (cancer) in their hosts. Of the various human DNA viruses, human papillomaviruses (HPV), Hepatitis B virus (HBV), Epstein-Barr virus (EBV) and Kaposi sarcoma herpes virus have been reported to cause cancer in humans. The human ‘T’ cell leukemia virus type 1 (HTLV1) and Hepatitis C virus (HCV) of RNA type are also reported to cause cancer. HPV have been implicated in the development of many cancers, e.g., squamous cell carcinoma of cervix, oral cancer and laryngeal cancer. Bovine papillomavirus (BPV) is known to cause epithelial and mucosal tumours in cattle. HBV and HCB viruses may be the primary cause of hepatocellular carcinoma (HCC). EBV (a member of herpes family) has been reported to cause lymphomas and nasopharyngeal carcinomas.