onkogena

Onkogena is a term used in genetics and oncology to describe a gene that has the potential to cause cancer when mutated or expressed at high levels. In English, the corresponding term is oncogene. Onkogena originate from normal cellular genes called proto-oncogenes that regulate cell growth, division, and survival. When mutated by point mutations, gene amplification, or chromosomal rearrangements, they become oncogena and can contribute to uncontrolled cell proliferation.

Most activation of onkogena is dominant, meaning a single altered allele can influence cancer development, often in combination with additional genetic changes. Activation mechanisms include gain-of-function mutations, gene amplification, and chromosomal translocations that place a gene under a strong promoter or create fusion proteins with constitutive activity, as seen with BCR-ABL in leukemias.

Onkogena encode proteins that operate in key cellular pathways controlling growth and survival. These include receptor tyrosine kinases (such as EGFR and HER2), signal transducers (RAS, RAF, PI3K), transcription factors (MYC), and regulators of the cell cycle (cyclin D1). Their dysregulation can promote increased proliferation, resistance to apoptosis, and angiogenesis, facilitating tumor progression.

Clinical relevance is central to the study of onkogena. They are major targets for cancer therapy; inhibitors tailored to specific oncogenic drivers—such as BCR-ABL inhibitors in chronic myeloid leukemia and HER2 inhibitors in breast cancer—are established treatment options. Detection of oncogenic mutations or amplifications also guides prognosis and therapeutic decisions.

Historically, the concept emerged from research on retroviral oncogenes in the late 20th century and the later identification of proto-oncogenes in normal cells, leading to the distinction between oncogenes and tumor suppressor genes.