Breast Cancer :: essays research papers

Scientists have finally found out why MPA medroxyprogesterone, otherwise known as Provera performs just as well in low doses in small children who are dealing with early sex traits, as it does for women in high doses with breast cancer. You may have heard of Provera before as the drug that delivers hormone replacement therapy for women who are going through menopause. Two scientists, named Lee and Auchus were trying to figure out why Provera is able to treat both early puberty as well as breast cancer. During the pre-teen years a chemical is released in the brain called gonadotropin-releasing hormone (GnRH). In a normal pre-teen body GnRH tells the ovaries and testes when to start making steroids. Low doses of Provera have shown to bind to the receptors in the brain and block GnRH production. There are certain disorders that children can develop- when their GnRH is not released into the brain. For instance, gonadotropin-independent precocity, this is when the Childs ovaries or testes still make steroids even without the release of GnRH. Since these children are still producing steroids without GnRH being released, low doses of Provera are not effective. For the body to produce steroid hormones it must convert cholesterol into estrogens and other related substances. In order for this process to take place, several steps are involved which are controlled by a certain enzyme. In knowing this, Lee wanted to find out if blocking the action of an enzyme would be reached with high doses of Provera. What Lee and Auchus found out was that Provera could inhibit certain enzymes, (3HSDII) which influence hormone production, that low doses of Provera could disrupt GnRH production and high doses were needed for a therapeutic effect. By knowing all this, it brings about new ideas for drug therapy when dealing with certain diseases. Not only that, but 3HSDII enzyme may be great to treat breast cancer. In this study Lee and Auchus used yeast cells instead of human cells. This allows them to study a single enzyme along with the effects that drugs may have on the production of steroids. Another advantage in using yeast cells is that these cells allow the maximum amount of an enzyme, cholesterol and protein needed, in order for the enzyme to perform. I believe that Lee and Auchus expected these results based on their findings, but at the same time were surprised by some of their findings in regards to other diseases they will be able to treat based on this research.