A protein-blocking compound has been found to impair sperm production in mice without the use of hormones

By Roxanne Khamsi

The discovery of a hormone-free way to immobilize sperm in mice could lead to the development of oral contraceptives for men. (This image actually shows Eucalyptus macrocarpa stamens under high magnification, which somewhat resemble sperm cells swimming en masse.) Image: flickr/Squil

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From Nature Medicine's "Spoonful of Medicine" blog:

The serendipitous finding that a potential cancer-fighting compound temporarily halts sperm production in mice has seeded new hopes for a reversible male contraceptive pill. At a time when the only non-hormonal contraceptive choices for men consist of condoms and vasectomies, the finding, published today in the journal Cell, has stirred the interest of pharmaceutical companies, although its quite far from entering clinical trials.

Several new contraceptives that rely on steroid hormones are in the works to reduce sperm production in men. However, most products developed to date seem to carry undesirable side effects, such as acne and perturbations of cholesterol levels. So, scientists have sought to halt sperm production with compounds that do not alter hormones, targeting everything from calcium ion channels on the tails of sperm to the production of retinoic acid, a metabolite of Vitamin A that has a role in their development. A team led by Dolores Mruk at the Population Councils Center for Biomedical Research in New York has even reported in Nature Medicine on the discovery of a chemical compound known as Adjudin that can stop sperm-forming cells from adhering to the Sertoli cells that nurture them.

The new findings announced today also describe a non-hormonal drug for stopping spermbut contraception was the furthest thing from the minds of James Bradner and his colleagues at the Dana-Farber Cancer Institute who initially developed the experimental compound.

As we reported last year, Bradners team had investigated a small molecule called JQ1 for its ability to thwart cancer by acting on a protein named BRD4. They showed success in mice with multiple myeloma, and other groups soon reported similar findings in animal models of leukemia and lymphoma. Bradner has been downright evangelical about the drug ever since, shipping it to more than 250 labs worldwide, according to a profile of Bradner published last week in Nature.

Link:

Cancer-Fighting Compound Might Double as Reversible Male Contraceptive