Study shows telomere length in humans can be altered by medical drugs

WHAT:  Scientists at the National Institutes of Health are reporting evidence that human telomeres can be favorably lengthened by medical drug treatment.  Telomeres are the ends of our chromosomes and function to protect them from damage. Over time, telomeres shorten, and this shortening has been linked with increased disease risk. The NIH results appear in this week’s New England Journal of Medicine.

The study sought to help people with inherited telomere diseases. Their telomeres shorten much more rapidly than normal.  Such patients might go on to develop bone marrow failure (caused by life-threatening low blood counts), lung fibrosis, liver cirrhosis, and an increased risk of certain cancers.

Male sex hormones have been in use since the 1960s to treat patients with bone marrow failure. Recently, in tissue culture and in animal models, sex hormones were found to regulate telomere elongation and scientists wondered if they might be beneficial in treating telomere disorders in humans.

In the NIH study, scientists administered the synthetic sex hormone, danazol, to a small group of participants with rare telomere disorders and bone marrow failure in an effort to slow their rapid telomere loss. In addition to slowing telomere loss, the drug unexpectedly appeared to elongate telomeres in almost all study participants. The treatment also improved blood counts in most study participants, and some who were dependent on blood transfusions no longer required them. In fact, when the participants stopped taking danazol, their telomeres shortened again.

In addition to primary support by the NHLBI, the current study is also supported by the National Human Genome Research Institute and the National Institute of Diabetes and Digestive and Kidney Diseases.

WHO:  Danielle Townsley, M.D., staff clinician in the Hematology Branch at the NHLBI and primary author of the study, and Neal Young, M.D., Hematology Branch Chief in the NHLBI Cell Biology Section, are available to comment on the findings and implications of this research.

CONTACT:  For more information or to schedule an interview, please contact the NHLBI Office of Science Policy, Engagement, Education, and Communications at 301-496-5449 or nhlbi_news@nhlbi.nih.gov (link sends e-mail).