Neues Steroidhormon hat eigenen Reiz

8. Oktober 1998

Neues Steroidhormon hat eigenen Reiz

8. Oktober 1998

La Jolla, CA – Das erste Steroidhormon, das seit 30 Jahren entdeckt wurde, ist ein chemischer Verwandter des Moleküls, das Schweine zu Trüffeln lockt, und wie dieser seltene und schwer fassbare Pilz steht es für sich allein.

Previously discovered steroid hormones boost or turn on genes. The new hormone, described in the Oct. 8 issue of Natur, defines a tantalizing new mode of action since it is the first hormone that reverses or halts gene activity.

The study’s lead author, Barry Forman, MD, of the City of Hope Diabetes Center and formerly of The Salk Institute, along with colleagues at Salk and Baylor College of Medicine, have demonstrated that the hormone, androstanol, interacts with a receptor protein called CAR?. This protein normally binds to genes and stimulates their activity but, when bound by androstanol, acts as a switch to turn genes off.

Like its fungal counterpart that gives truffling pigs pause, “androstanol seems to stop gene activity in its tracks,” according to co-author Ron Evans, Salk Professor and Howard Hughes Medical Institute investigator.

Androstanol is chemically related to androgen, a hormone that stimulates normal development of male sex organs and, in humans, affect secondary sex characteristics including hair loss and aggressive behavior. In some studies, androstanol appears to be a pheromone that enhances men’s attractiveness to women.

“At this time, however, we have no evidence for CAR? being a pheromone receptor. Because androgens are involved in complex behavior and physiological responses, we do not yet know where CAR? fits in the grand scheme,” said Evans. “The discovery of a new receptor clearly reveals the existence of a new pathway and provides a precise way to attack the problem.”

The equivalent of androstanol in plants, including truffles, is androstenedione, the nutraceutical that gained notoriety for its use by Mark McGwire, who set a new home run record this summer for the St. Louis Cardinals. In the current study, androstenedione was a very weak activator of the androgen receptor “and thus how it might work remains unclear,” commented Evans. “Mostly this work reinforces the idea that sex steroids contribute in complex ways to human behavior and disease. This gives us one of the first new tools in decades to address these problems.”

Senior author on the study is David D. Moore, PhD of Baylor College of Medicine. Other co-investigators include Iphigenia Tzameli, PhD of Baylor; Jasmine Chen, MS of City of Hope; Hueng-Sik Choi, PhD of the Chonnam National Universtiy, Kwangju, Republic of Korea; Devendranath Simha, PhD of Massachusetts General Hospital; and Wongi Seol, PhD of Dana-Farber Cancer Institute.

FOR ADDITIONAL INFORMATION: B. J. Almond, Baylor College of Medicine, (713) 798-4712, balmond@bcm.tmc.edu Mike Byrne, City of Hope National Medical Center, (626) 359-8111

Das Salk Institute for Biological Studies, in La Jolla, Kalifornien, ist eine unabhängige gemeinnützige Einrichtung, die sich grundlegenden Entdeckungen in den Biowissenschaften, der Verbesserung der menschlichen Gesundheit und Lebensbedingungen sowie der Ausbildung zukünftiger Forschergenerationen widmet. Das Institut wurde 1960 von Jonas Salk, MD, mit einer Landschenkung der Stadt San Diego und der finanziellen Unterstützung der March of Dimes Birth Defects Foundation gegründet.