karsinogeeneja

Karsinogeeneja are genes whose altered function contributes to the development or progression of cancer. The term can refer to inherited variants that raise lifetime cancer risk as well as somatic mutations that arise in cells during a person’s life. They include oncogenes, tumor suppressor genes, and genes involved in the DNA damage response and repair.

Oncogenes, when mutated or overexpressed, promote uncontrolled cell growth, while tumor suppressor genes normally restrain proliferation and survival; loss-of-function mutations in these genes remove growth controls. DNA repair genes, when defective, increase the global rate of mutations and genomic instability, fueling cancer development. Mutations can be germline (inherited) or somatic (acquired in a specific cell lineage).

Common examples include oncogenes such as KRAS, BRAF, and MYC; tumor suppressors such as TP53, RB1, and PTEN; and DNA repair genes such as BRCA1, BRCA2, MLH1, MSH2, and MSH6. Inherited pathogenic variants in these genes underlie certain cancer predisposition syndromes (for example, BRCA1/2 in hereditary breast and ovarian cancer; TP53 in Li-Fraumeni syndrome), whereas most cancers involve somatic alterations in these gene classes.

Mechanistically, karsinogeeneja influence cancer through altered signaling pathways, impaired DNA damage response, and accumulation of additional mutations that drive clonal expansion and tumor progression. Clinically, genetic testing can identify pathogenic variants for risk assessment, and therapies may exploit specific gene defects, such as PARP inhibitors in BRCA1/2-mutant cancers or targeted pathway inhibitors in tumors with particular oncogenic alterations.