Telomere Effect

Telomeres are specialized DNA-protein complexes located at the ends of eukaryotic chromosomes, composed of TTAGGG repeat sequences. Their function is to protect chromosome ends and prevent the loss of genetic information that may occur during DNA replication. Due to the mechanism of action of DNA polymerase, a portion of the DNA is lost from the ends with each cell division, leading to telomere shortening.

Telomerase is an RNA-containing reverse transcriptase enzyme (hTERT) that replenishes telomeric sequences and compensates for telomere shortening. However, this enzyme is typically inactive in most somatic cells. Telomerase activity is generally high in:

• Germline cells
• Cancer cells
• Some stem cells

This condition can lead to cellular immortality, making the telomere effect a significant factor in cancer biology.

Telomere length is considered a biomarker of biological age. Long telomeres are associated with a younger cellular profile, while short telomeres are linked to aging, cellular senescence, and disease. Anti-aging approaches under investigation include:

• Telomerase activators (e.g., TA-65)
• Lifestyle interventions such as meditation, exercise, and healthy nutrition
• Strategies such as epigenetic modifications

Telomere length can serve as both a cause and consequence in the following diseases:

• Cardiovascular diseases
• Type 2 diabetes
• Alzheimer’s disease
• Depression and chronic stress disorders

Telomere testing is performed in some specialized laboratories to determine biological age.

Cancer cells acquire the ability to divide indefinitely by reactivating telomerase. Therefore, telomerase inhibitors (e.g., imetelstat) represent potential therapeutic targets in cancer treatment. Research is currently in clinical trial stages.