内分泌信号传导8.pdf

Environmental Signaling (ES-101) Case 8: Marked for Disease Session Objectives Students will be able to: Describe epigenetics and how it works Discuss evolving concepts of disease causation Explain how environmental exposures might cause long-term and even transgenerational changes to the epigenome In this session students will consider a story, based on historical facts, about DES, disease and epigenetics. Read this scenario, based on a real situation, to the group, or have a student read it out loud. In his office across from his lab, the tall scientist was bent over his desk, reading the draft manuscript he had prepared with a colleague. Pushing back from the desk with his Birkenstocks, he leaned back in the chair. As it creaked he put his hands behind his head, elbows sticking out, and stared at the ceiling in concentration. The manuscript described experiments on mice exposed to diethylstilbestrol (DES). This chemical was prescribed to pregnant women for decades before being banned for use when it was linked to rare cancers in the children of mother who had taken it. The experiments on mice in this scientist’s lab confirmed that exposure in the uterus to DES led to uterine malformations and cancers. But they also showed that the offspring of exposed mice--the “grandchildren” of the mice who were given DES--showed the same kinds of disease. The experiments were repeated, the data incontrovertible. This result was exciting, but also a little scary. Scary because of its real-world implications for sure, but scary also because there was no known mechanism for how it could occur. CAPTION: Diethylstilbestrol (DES) is a synthetic chemical that is strongly estrogenic and has been used in humans and livestock CREDIT: ChemIDPlus, National Library of Medicine CAPTION: Genistein is an isoflavone found in high concentrations