Longer telomeres linked to increased risk of brain cancers

New research led by scientists at UC San Francisco has revealed a link between common gene variants that lead to longer telomeres and an increased risk of developing deadly brain cancers known as gliomas.

Variants in two telomere-related genes known as TERT and TERC are respectively carried by 51 per cent and 72 per cent of the general population.

Telomeres are the caps on chromosome ends thought by many scientists to confer health by protecting cells from ageing.

It is thought that the benefits conferred by these variants in terms of improved cellular robustness outweigh the increased risk of developing gliomas, which are invariably fatal but relatively rare.

A massive genomic analysis of 40,000 individuals conducted at the University of Leicester found that shorter telomeres were associated with a significantly increased risk of cardiovascular disease.

The first phase of the new study involved analysing genome-wide data from 1,644 glioma patients and 7,736 healthy control individuals, including some who took part in The Cancer Genome Atlas project sponsored by the National Cancer Institute and National Human Genome Research Institute.

This confirmed the link between TERT and gliomas established in previous research and identified TERC as a glioma risk factor for the first time.

As both genes were used to regulate the action of telomerase, the enzyme that maintains telomere length, the research team analysed the Leicester data and found the two variants associated with glioma risk were also linked with greater telomere length.

Much previous research has linked longer telomeres to better health. However, as cancer cells promote their longevity by maintaining telomere length, many drug companies have searched for drugs to specifically target and block telomerase in tumors in the hopes that cancer cells will accumulate genetic damage and die.

TERT variants are also thought to play a role in lung, prostate, testicular and breast cancers, and TERC variants in leukemia, colon cancer and multiple myeloma. The research thus has a potentially much broader relevance than the glioma-related study.