What is oncogene and proto-oncogene?

Proto-oncogenes are a group of genes that cause normal cells to become cancerous when they are mutated (Adamson, 1987; Weinstein & Joe, 2006). Mutations in proto-oncogenes are typically dominant in nature, and the mutated version of a proto-oncogene is called an oncogene.

How does proto-oncogene become oncogene?

The conversion of a proto-oncogene to an oncogene is called activation. Proto-oncogenes can become activated by a variety of genetic mechanisms including transduction, insertional mutagenesis, amplification, point mutations, and chromosomal translocations.

What is a proto-oncogene and what does it do?

Proto-oncogenes are genes that normally help cells grow. When a proto-oncogene mutates (changes) or there are too many copies of it, it becomes a “bad” gene that can become permanently turned on or activated when it is not supposed to be. When this happens, the cell grows out of control, which can lead to cancer.

What are the types of oncogenes?


Oncogene Type of human neoplasia
Pancreatic ductal adenocarcinoma
N-RAS Acute myelogenous leukemia
Chronic myelogenous leukemia
ABL Chronic myelogenous leukemia

Is telomerase a proto-oncogene?

Oncogenes, i.e. mutated or otherwise deregulated proto-oncogenes, are typically regarded as genes that promote the uncontrolled growth of cells. In this context, telomerase is clearly not an oncogene.

Is p53 a proto-oncogene?

The p53 proto-oncogene can act as a suppressor of transformation.

How do proto-oncogenes regulate the cell cycle?

Oncogenes in their proto-oncogene state drive the cell cycle forward, allowing cells to proceed from one cell cycle stage to the next. This highly regulated process becomes dysregulated due to activating genetic alterations that lead to cellular transformation.

Why are proto-oncogenes dominant?

Mutations in proto-oncogenes are usually acquired. Having a mutation in just 1 of the pair of a particular proto-oncogene is usually enough to cause a change in cell growth and the formation of a tumor. For this reason, oncogenes are said to be dominant at the cellular level.

Is tert a proto-oncogene?

Telomerase is the critical enzyme in overcoming growth limitations due to telomere dysfunction, but it does not cause growth deregulation and hence is not an oncogene.

What are some examples of proto-oncogenes?

Examples of proto-oncogenes

  • pancreatic cancer.
  • lung carcinoma and lung tumors.
  • colon tumors.
  • thyroid tumors.

Is p53 a proto oncogene?