Rous sarcoma virus

Rous sarcoma virus (RSV) is a retrovirus and is the first virus to have been identified as causing cancer. It was discovered in 1911 by Peyton Rous, an American pathologist, and is named after him. RSV causes sarcoma, a type of cancer that affects connective tissues such as bones and muscles, in chickens.

History

Peyton Rous discovered the Rous sarcoma virus in 1911 while working at the Rockefeller Institute for Medical Research. He found that a cell-free extract of a chicken tumor could transmit the disease to healthy chickens, leading to the development of similar tumors. This was a groundbreaking discovery as it was the first time a virus was linked to the cause of cancer.

Structure and Genome

Rous sarcoma virus is a type of retrovirus, which means it has a single-stranded RNA genome. The virus is enveloped and has a spherical shape. The genome of RSV contains four genes: gag, pro, pol, and env. The gag gene codes for the virus's structural proteins, pro and pol code for the virus's enzymes, and env codes for the virus's envelope proteins.

Pathogenesis

The Rous sarcoma virus causes cancer by integrating its genetic material into the host cell's DNA. This is done through a process called reverse transcription, where the virus's RNA is converted into DNA by the enzyme reverse transcriptase. Once integrated, the viral genes are transcribed and translated by the host cell's machinery, leading to the production of viral proteins and the replication of the virus. One of these proteins, the v-src protein, is a mutated version of a normal cellular protein and is responsible for the transformation of normal cells into cancer cells.

Significance

The discovery of the Rous sarcoma virus has had a significant impact on the field of oncology. It has led to the identification of many other oncogenes, genes that have the potential to cause cancer, and has contributed to our understanding of how cancer develops at a molecular level. Furthermore, the study of RSV has also contributed to the development of viral vectors for gene therapy.

See also

• Oncovirus
• Peyton Rous
• Retrovirus
• Sarcoma