Home Science Longer Telomeres, A Heavily Hyped Goal Of Anti-Aging Tonics And Salves, Create A Predisposition To Cancer

Longer Telomeres, A Heavily Hyped Goal Of Anti-Aging Tonics And Salves, Create A Predisposition To Cancer

Longer Telomeres, A Heavily Hyped Goal Of Anti-Aging Tonics And Salves, Create A Predisposition To Cancer

By 1990, scientists knew that telomeres are repetitive DNA sequences found at the tips of the long strings of DNA that are chromosomes. That year in the journal Nature, researchers at McMasters University in Ontario and Cold Spring Harbor in New York made a breakthrough announcement. It was that the DNA content of telomeres decreases as the body hosting the telomeres ages.

Merchandisers made frenetic use of the discovery. Telomere claims on anti-aging remedies and creams proliferated, as they still do. Magazine articles about matters like how to lengthen your own telomeres became popular. The beauty industry began promoting miracle-in-a-jar products like Estée Lauder’s Re-Nutriv Ultimate Diamond, which costs $450/bottle (it contains black diamond truffles) and “supposedly” preserves the telomere length of skin tissue.

Cue the new research from cell biologist and geneticist Titia de Lange’s lab at New York’s Roosevelt University. It may quiet some of the hullabaloo. De Lange’s recent work, published in the journal eLife, provides the first proof that, by limiting cell division, telomeres repress cancer.

“We have known since the early 1990’s that each time a cell divides, telomeres shorten and chromosomes re-form,” De Lange explained in a phone call. “Even back then I speculated, as did others, that this constitutes a system that prevents cancer cells from developing and multiplying. Unfortunately, we didn’t yet have proof.”

As explained by de Lang, the proof now lies in an analysis of some of the genes and proteins controlling telomere length as well as in the health histories of four Dutch families.

She detailed in a recent phone call that telomeres regulate how many times a cell can divide. They do so by shortening with each cell division. After about 50 divisions, the cell’s telomeres are entirely depleted, at which point the cell itself cannot divide further. Programmed cell death ensues. Even though it results in cell death, limiting cell division is healthy, for each time a cell divides, chromosomes have to re-form. Each time chromosomes reform, mutations that cause cancer can creep in. By limiting cell reproduction, telomeres constrain the number of opportunities for the onset of cancer.

According to de Lange, this “tumor suppression pathway” has long been suspected and has even been documented in mouse populations. “We’ve seen that lab mice with shorter telomeres get less cancer,” she noted. De Lange’s new work finally gives evidence about the deleterious effect of longer telomeres.

To confirm the suspected link between telomere length and cancer, de Lange and her associates worked with cell samples taken by Dutch physicians from the members of four families. In these families, cancer was extraordinarily common. The physicians had already found two genetic mutations in TINF2, a gene that encodes for TIN2, which is a protein that’s instrumental in regulating telomere length. Isabelle Schmutz, a post-doc in de Lange’s lab, used CRISPR technology to engineer human cells with exactly the same mutations.

The engineered cells were normal human cells in all ways but one. Their telomeres were very long, as were the telomeres in cultures taken from the Dutch patients. According to de Lange, the patients’ telomeres were “far above the 99th percentile in length.”

Plagued at birth with extra-long telomeres in each cell of their bodies, the family members had developed a broad range of cancers.

“Telomere shortening as a tumor suppressor is incredibly powerful,” de Lange noted. “If these people had been born with normal length telomeres they probably would never have gotten the cancers that they did. In you and me, the normal control that telomeres place on cell reproduction has probably already prevented many cancers from occurring.”

De Lange’s finding that long telomeres can dramatically predispose people to cancer runs directly counter to the vision of long telomeres as a biochemical version of the fountain of youth. Perhaps because of this, she is quite clear about one takeaway from her work. When asked whether pharmaceutical companies should attempt to develop products that can tweak telomere length in either direction in healthy individiuals, she had a very short and enthusiastic answer.

“No.”

This article is auto-generated by Algorithm Source: www.forbes.com

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