Oncogenic viruses

Definition

Oncogenic viruses are viruses that can cause cancer in their host organisms by altering normal cellular processes. They integrate their genetic material into the host's DNA, leading to uncontrolled cell growth and tumor formation.

5 Must Know Facts For Your Next Test

1. Oncogenic viruses can be either DNA or RNA viruses.
2. Human Papillomavirus (HPV) is an example of an oncogenic virus associated with cervical cancer.
3. Hepatitis B and Hepatitis C viruses are linked to liver cancer.
4. Oncogenic viruses contribute to about 15-20% of all human cancers.
5. These viruses often disrupt tumor suppressor genes or activate oncogenes in the host cells.

Review Questions

• What is the primary mechanism by which oncogenic viruses cause cancer?
• Name two examples of oncogenic viruses and the types of cancer they are associated with.
• Approximately what percentage of human cancers are linked to oncogenic viral infections?

Related terms

Proto-oncogene: A normal gene that can become an oncogene due to mutations or increased expression.

Tumor suppressor gene: A gene that protects a cell from one step on the path to cancer; when mutated, it allows for uncontrolled cell division.

Retrovirus: A type of RNA virus that inserts a copy of its genome into the DNA of a host cell as part of its replication cycle, some retroviruses are oncogenic.