Oncogenes (literally ‘cancer genes’) were first discovered in the genetic material of viruses that are capable of causing cancers in animals. The immediate importance of oncogenes in human cancer became clear with the discovery that most of the virus oncogenes had very close relatives that were present in the normal cell.
- A particular type of gene was first discovered in viruses that can cause cancer in animals by altering the cells in the animals which they infect.
- These genes were then found to be closely related to genes in normal human and animal cells.
- Such genes are called oncogenes.
- It is now known that our oncogenes normally control the proliferation and differentiation of our cells in a beneficial way.
- It is now also known that if our oncogenes become altered or disordered, they can contribute to the development of a cancer.
- Alterations in oncogenes can be brought about in a number of ways.
- It is thought likely that at least some of the 'causes of cancer' that we shall identify, such as smoking and radiation, produce cancer by altering oncogenes and other genes.