Attempts to Prevent Cancer by Lengthening Telomeres Lead to...Cancer

Earlier this year, scientists were able to successfully lengthen telomeres for the first time by using artificial RNA to encode a telomere-extending protein. This was celebrated as a revolutionary step in “turning back the internal clock” of human cells to prevent aging.

Telomeres are non-coding DNA sequences that reside at the ends of chromosomes. During cell division, a portion of DNA at the end of a strand is lost. Usually this will not pose a problem because the region discarded will be part of the telomere, but once the telomere sequences are all gone, coding regions of your DNA are lost instead, leading scientists to associate telomere shortening with aging and cardiovascular diseases.

The connection between telomere shortening and cancer remains unclear because telomere length varies greatly from person to person due to a huge number of factors, making it extremely difficult to study. However, a study at the University of Chicago has linked long telomeres with increased risk of lung cancer, specifically lung adenocarcinoma, which doubled in risk with every 1000 base pairs in the telomere. The study also tested for breast, colorectal, ovarian, and prostate cancers with no significant results.

The team suggests that the correlation may stem from the fact that longer telomeres allow for more rounds of cell division, causing cells to live longer and accumulate more mutations. “The complex relationship between telomeres and cancer risk is one that we need to further understand,” says Brandon Pierce, PhD, who led the study. “This study gives us an estimate of a causal relationship that could serve as a guidepost for the development of interventions in the future.”

Images courtesy of Healthycell, Stanford, and Isagenix.