Due to telomerase inhibition, activity, or expression, these drugs might kill tumor cells by allowing telomeres to shrink or by provoking apoptosis. First of all, this process might have a chance to be cell-specific without serious side effects (Fig. 1).
How does telomerase help cancer cells?
Cancer cells often avoid senescence or cell death by maintaining their telomeres despite repeated cell divisions. This is possible because the cancer cells activate an enzyme called telomerase, which adds genetic units onto the telomeres to prevent them from shortening to the point of causing senescence or cell death.
What is telomerase and how is it involved in cancer?
Telomerase activity is closely related to the life stages of the body. The enzyme is active during embryonic development. Cancer cells are characterized by high telomerase activity, which enables cells to divide indefinitely. Telomerase is active in 85–95% of cancers (3,4).
Can telomerase cure cancer?
Although the inhibition of telomerase may strip some cancers of their immortality, cancers are still viable and largely unaffected by the loss of telomerase.
Why is telomerase a potential target for cancer therapy?
Telomerase is an attractive target antigen for cancer immunotherapy because it is expressed almost universally in human cancers and is functionally required to sustain malignant tumor long-term growth .
What is the role of the telomerase?
Telomerase is a cellular reverse transcriptase that helps to provide genomic stability in highly proliferative normal, immortal, and tumor cells by maintaining the integrity of the chromosome ends, the telomeres. The activity of telomerase is associated with the majority of malignant human cancers.
How can an active telomerase lead to cancer?
A rare cell that escapes crisis almost universally does so by reactivating telomerase and this cell can now become a cancer cell with limitless potential to divide. Almost all cancer cells have short telomeres and thus inhibitors of telomerase should drive such cancer cells into apoptotic cell death.
What happens if you inhibit telomerase in cancer cells?
Telomerase reactivation in malignant cells after genomic instability causes cancer progression. Inhibiting telomerase caused tumor cell death but also led to alternative lengthening of telomeres (ALT) independent of telomerase.
Do telomeres and telomerase show promise in the fight against cancer What about aging?
Studies have found shortened telomeres in many cancers, including pancreatic, bone, prostate, bladder, lung, kidney, and head and neck. Measuring telomerase may be a new way to detect cancer. If scientists can learn how to stop telomerase, they might be able to fight cancer by making cancer cells age and die.
What could be a negative effect of telomerase activity?
A final concern is that telomerase inhibitors could lead to increased genomic instability in surviving cells (Hackett and Greider, 2002, Harrington and Robinson, 2002), leading to more advanced or aggressive tumors.
Is it possible to use telomerase as a biomarker or a target for cancer therapy?
Telomerase activity may, therefore, be a useful biomarker for diagnosis of malignancies and a target for inactivation in chemotherapy or gene therapy.
Why is telomerase important in DNA replication?
They protect chromosome ends from DNA degradation, recombination, and DNA end fusions, and they are important for nuclear architecture. Telomeres provide a mechanism for their replication by semiconservative DNA replication and length maintenance by telomerase.