How do cancer cells not run out of telomeres?
How do cancer cells not run out of telomeres?
Answered
Cancer cells are capable of avoiding the normal process of telomere shortening through the activation of telomerase, an enzyme that synthesizes the repetitive DNA sequence at the ends of chromosomes. In normal somatic cells, telomerase activity is low or absent, resulting in the progressive shortening of telomeres with each cell division. However, cancer cells often exhibit reactivation or upregulation of telomerase, which replenishes the telomeres, allowing them to bypass the cellular limit on divisions (known as the Hayflick limit). This allows the cancer cells to continue proliferating uncontrollably. In some cancers, other mechanisms, such as alternative lengthening of telomeres (ALT), can also be used to maintain telomere length without telomerase. These mechanisms help the cancer cells avoid the normal growth arrest that would occur when telomeres shorten too much, thus contributing to the immortality of cancer cells.
BNO Team