By Jove!

日期:2017-05-02 06:02:33 作者:阮光 阅读:

By Bob Holmes A HORMONE used in oral contraceptives may protect against ovarian cancer in an unexpected way—by triggering damaged cells to commit suicide. Taking the Pill for even a few years greatly reduces the risk of ovarian cancer. Most researchers have assumed that this is because it prevents ovulation, which damages the ovary. Not so, says Gustavo Rodriguez of Duke University Medical Center in Durham, North Carolina. He and his colleagues gave a synthetic progestin to 18 macaque monkeys in a monthly cycle similar to that used for oral contraceptives. After 35 months, six times as many cells in the ovary wall of these monkeys suffered programmed cell death, or apoptosis, compared with animals not given the hormone (Journal of the Society for Gynecologic Investigation, vol 5, p 271). Since apoptosis targets genetically damaged cells, progestin may eliminate precancerous cells. “You simply wipe the slate clean of these abnormal cells and then start over again,” says Rodriguez. If the same process occurs in humans, then even post-menopausal women may be able to prevent ovarian cancer by taking progestin, says Rodriguez. But progestin also causes breast cells to multiply and may increase the risk of breast cancer. “There would need to be some concern about that,” says Eugenia Calle, an epidemiologist with the American Cancer Society in Atlanta,