People with either very short or very long telomeres are at increased risk of developing cancer – this is called the Telomere Length Paradox. In this video we discuss how telomere length can impact cancer risk.

Telomeres, the protective caps on the ends of our chromosomes, can act as a defense mechanism to prevent tumor growth by stopping cell division when they are too short.

When this occurs the cell either becomes senescent – stops dividing, or undergoes apoptosis – when the cell is programmed to die. However, this mechanism is not perfect.

The idea is that the more times a cell has divided, the more likely that it acquired a dangerous mutation along the way.

Since unexpected mutations in a cell can lead to cancer, a programmed limit to the number of times a cell can divide provides an important barrier to tumor growth in species with long life spans, such as ourselves.

Many cancer cells, however, exhibit mutations prevent this limit to tumor growth, for example a common mutation in cancer cells is when the p53 tumor suppressor gene stops functioning properly.

This is part of a series of six videos where we explore telomeres, telomere length and telomerase, as well as the impacts they have on our health and aging.

Watch the next video investigating techniques to measure telomere length here.

Missed the previous video on Telomere Biology Disorders? Find it here.

RepeatDx is a leading clinical laboratory for telomere length testing. You can find out more on our website: www.repeatdx.com

Follow us on Twitter: @RepeatDx

References

1. Aviv, A., Anderson, J. J. & Shay, J. W. Mutations, Cancer and the Telomere Length Paradox. Trends Cancer 3, 253-258, doi:10.1016/j.trecan.2017.02.005 (2017).

2. Shay, J. W. & Wright, W. E. Telomeres and telomerase: three decades of progress. Nat Rev Genet 20, 299-309, doi:10.1038/s41576-019-0099-1 (2019).

3. Barthel, F.P., Wei, W., Tang, M., Martinez-Ledesma, E., Hu, X., Amin, S.B., Akdemir, K.C., Seth, S., Song, X., Wang, Q., et al. (2017). Systematic analysis of telomere length and somatic alterations in 31 cancer types. Nat Genet 49, 349-357.

4. McNally, E. J., Luncsford, P. J. & Armanios, M. Long telomeres and cancer risk: the price of cellular immortality. J Clin Invest 129, 3474-3481, doi:10.1172/JCI120851 (2019).

5. Halaschek-Wiener, J. et al. Reduced telomere length variation in healthy oldest old. Mech Ageing Dev 129, 638-641, doi:S0047-6374(08)00163-2 [pii] 10.1016/j.mad.2008.07.004 (2008).