The sex hormone danazol increased telomere length in patients with telomere diseases, according to a phase 1–2 study published in the May 19 issue of the New England Journal of Medicine.
"Not only was telomere loss prevented by treatment with danazol in our patients, but a mean increase of 386 bp telomeric repeats had occurred by study completion, with improvement usually observed early during the course of hormone therapy," write Danielle M. Townsley, MD, from the National Heart, Lung, and Blood Institute in Bethesda, Maryland, and colleagues. "Hematologic improvement in all blood counts accompanied telomere elongation."
In an accompanying editorial, Peter Landor, MD, PhD, from the University of Groningen in the Netherlands, writes that the "exciting findings...provide food for thought about the role of telomeres and telomerase in hematopoietic stem cells."
Telomere diseases such as dyskeratosis congenita, aplastic anemia, pulmonary fibrosis, and liver cirrhosis result from inadequate or absent telomere maintenance and repair from mutations in the genes responsible for those functions. That failure can also contribute to bone marrow failure and an increased risk for cancer. Previous study of a mouse model with telomere dysfunction, however, had shown hematologic improvement and a lengthening of telomeres after male hormone treatment.
"Androgens have been a therapeutic option for marrow failure syndromes since the 1960s, without a clear mechanism for their action," the authors write. "In retrospect, some patients with a response probably had telomere deficits."