Aberrant Activation of Telomere Maintenance Pathway

**Semantic type:** Cell or Molecular Dysfunction

**Definition:** In normal, non-stem cells, telomeres shorten with each cell division, which eventually leads to short telomeres that cannot be capped and cell cycle arrest (cell senescence). The activation of telomerase length maintenance pathways in tumor cells allows them to escape senescence and replicate indefinitely. These pathways can be aberrantly activated either through telomerase reactivation, which occurs due to mutations in the TERT gene or its promoter, or through an alternative lengthening of telomeres (ALT) pathway, which is usually associated with mutations in the ATRX gene.

**Synonyms:** - Telomere Maintenance Pathway Activation - Telomere Maintenance Pathway Deregulation