A key component of the enzyme telomerase, which is responsible for maintaining the length of telomeres at the ends of chromosomes.
In most somatic cells, telomerase activity is low or absent, leading to progressive telomere shortening with each cell division, which eventually triggers cellular senescence or apoptosis.
many cancer cells exhibit reactivation of telomerase, primarily through the upregulation of hTERT. This reactivation allows cancer cells to maintain their telomere length, enabling them to divide indefinitely and contributing to the immortality characteristic of cancer cells. The expression of hTERT is often associated with various types of cancer, including melanoma, breast cancer, and lung cancer.
| Cancer context | TERT biomarker | Clinical use |
| -------------- | ----------------------------- | ---------------------------------------- |
| Glioma | Promoter mutation | **WHO classification, prognosis** |
| Thyroid cancer | Promoter mutation | **Aggressiveness, recurrence risk** |
| Melanoma | Promoter mutation | Risk stratification |
| Bladder cancer | Promoter mutation (urine DNA) | **Noninvasive detection & surveillance** |
| HCC | Promoter mutation | Early event, prognosis |
Why TERT Is Valuable Despite Limited “Actionability”
-Telomere maintenance is mandatory for long-term tumor survival
-TERT activation is often an early, irreversible event
-Its presence signals a tumor that has escaped replicative limits
-That makes TERT one of the best markers of “point-of-no-return” biology.
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