Related Experiment Video

Updated: Aug 9, 2026

An In Vitro Model for Studying Cellular Transformation by Kaposi Sarcoma Herpesvirus
09:53

An In Vitro Model for Studying Cellular Transformation by Kaposi Sarcoma Herpesvirus

Published on: August 25, 2017

Retroviral oncogenes and TOR

M Aoki1, P K Vogt

  • 1Department of Molecular and Experimental Medicine, The Scripps Research Institute, 10550 North Torrey Pines Road, BCC-239, La Jolla, CA 92037, USA.

Current Topics in Microbiology and Immunology
|October 17, 2003
PubMed

Insights

Certain retroviruses use PI 3-kinase and Akt as oncogenes, causing tumors. Their oncogenicity is blocked by rapamycin, an inhibitor of the target of rapamycin (TOR) kinase pathway, crucial for cell transformation.

Area of Science:

  • Oncology
  • Molecular Biology
  • Virology

Background:

  • Retroviruses can act as oncogenes by incorporating PI 3-kinase and Akt.
  • These viral oncogenes induce tumors in vivo and transformation in vitro.

Purpose of the Study:

  • To investigate the role of the target of rapamycin (TOR) pathway in retroviral oncogenesis.
  • To determine the specificity of rapamycin's inhibitory effect on these oncogenic retroviruses.

Main Methods:

  • Utilized retroviral models expressing PI 3-kinase and Akt.
  • Assessed oncogenic transformation in cell culture and tumor formation in animals.
  • Tested the sensitivity of these viruses to rapamycin treatment.

Main Results:

  • Rapamycin specifically inhibited the oncogenicity of retroviruses utilizing PI 3-kinase/Akt.
  • Retroviruses with different oncogenes were insensitive to rapamycin.
  • Rapamycin targets the TOR kinase, affecting p70 S6 kinase and 4E-BP.

Conclusions:

  • The PI 3-kinase/Akt pathway's oncogenic transformation is dependent on TOR signaling.
  • TOR signaling to the translational machinery is essential for PI 3-kinase-driven oncogenesis.

More Related Videos

Retroviral Scanning: Mapping MLV Integration Sites to Define Cell-specific Regulatory Regions10:10

Retroviral Scanning: Mapping MLV Integration Sites to Define Cell-specific Regulatory Regions

Published on: May 28, 2017

Genome-wide RNAi Screening to Identify Host Factors That Modulate Oncolytic Virus Therapy08:51

Genome-wide RNAi Screening to Identify Host Factors That Modulate Oncolytic Virus Therapy

Published on: April 3, 2018

Related Concept Videos

Retrovirus Life Cycles01:10

Retrovirus Life Cycles

Retroviruses have a single-stranded RNA genome that undergoes a special form of replication. Once the retrovirus has entered the host cell, an enzyme called reverse transcriptase synthesizes double-stranded DNA from the retroviral RNA genome. This DNA copy of the genome is then integrated into the host’s genome inside the nucleus via an enzyme called integrase. Consequently, the retroviral genome is transcribed into RNA whenever the host’s genome is transcribed, allowing the retrovirus to...
Retroviruses02:33

Retroviruses

Retroviruses and retrotransposons both insert copies of their genetic elements into the genome of the host cell. Thus, the viral genes are passed on when the host genome is replicated or translated. A typical retroviral DNA sequence contains 3-4 genes that encode the different proteins required for its structural assembly and function as a molecular parasite. This DNA is transcribed into a single mRNA, which is very similar in structure to conventional mRNAs, i.e., it is capped at the 5’...
Mechanisms of Retrovirus-induced Cancers01:51

Mechanisms of Retrovirus-induced Cancers

Retroviruses are RNA viruses that have been shown to cause cancers in diverse species, including chickens, mice, cats, and monkeys. The RNA genomes of these viruses are first reverse-transcribed into single and then double-stranded DNA (dsDNA) copies. This dsDNA called proviral DNA then integrates into the host genome. Subsequently, the host cell transcribes the proviral DNA in concert with the chromosomal DNA. This leads to the production of viral RNA and proteins that assemble at the host...
Rous Sarcoma Virus (RSV) and Cancer01:03

Rous Sarcoma Virus (RSV) and Cancer

Rous Sarcoma virus or RSV was discovered by F. Peyton Rous in the year 1911 as a filterable transmissible agent that could cause tumors in chickens. He won a Nobel Prize for this discovery in 1966. His experiments clearly demonstrated that some cancers could be caused by infectious agents and led to the discovery of many more cancer-causing viruses in animals as well as humans.
RSV is a retrovirus that contains two copies of a plus-strand  RNA genome. Its genome consists of four main open...
Mechanisms of Retrovirus-induced Cancers01:51

Mechanisms of Retrovirus-induced Cancers

Retroviruses are RNA viruses that have been shown to cause cancers in diverse species, including chickens, mice, cats, and monkeys. The RNA genomes of these viruses are first reverse-transcribed into single and then double-stranded DNA (dsDNA) copies. This dsDNA called proviral DNA then integrates into the host genome. Subsequently, the host cell transcribes the proviral DNA in concert with the chromosomal DNA. This leads to the production of viral RNA and proteins that assemble at the host...
Rous Sarcoma Virus (RSV) and Cancer01:03

Rous Sarcoma Virus (RSV) and Cancer

Rous Sarcoma virus or RSV was discovered by F. Peyton Rous in the year 1911 as a filterable transmissible agent that could cause tumors in chickens. He won a Nobel Prize for this discovery in 1966. His experiments clearly demonstrated that some cancers could be caused by infectious agents and led to the discovery of many more cancer-causing viruses in animals as well as humans.
RSV is a retrovirus that contains two copies of a plus-strand  RNA genome. Its genome consists of four main open...