onkogéne

Onkogéne are genes that have the potential to cause cancer. Normally, these genes play a role in cell growth, division, and repair. However, when an onkogéne becomes mutated or overexpressed, it can lead to uncontrolled cell proliferation, a hallmark of cancer. Onkogénes are typically derived from proto-oncogenes, which are normal genes that regulate these essential cellular processes. A mutation or alteration in a proto-oncogene can transform it into an onkogéne.

The activation of an onkogéne can occur through various mechanisms. These include point mutations, gene amplification (resulting in multiple copies of the gene), chromosomal translocations (where a piece of one chromosome breaks off and attaches to another), or the insertion of viral DNA. Once activated, the onkogéne can promote tumor formation and progression by overriding normal cellular controls. For instance, some onkogénes encode proteins that stimulate cell division indefinitely, while others inhibit programmed cell death (apoptosis), allowing damaged cells to survive and multiply. Understanding the role of specific onkogénes is crucial for developing targeted cancer therapies that aim to inhibit their activity and control tumor growth.