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Archive - Apr 12, 2012

Genetic Adaptation of Fat Metabolism Key to Development of Human Brain

About 300,000 years ago, humans adapted genetically to be able to produce larger amounts of omega-3 and omega-6 fatty acids. This adaptation may have been crucial to the development of the unique brain capacity in modern humans. In today's life situation, this genetic adaptation contributes instead to a higher risk of developing disorders like cardiovascular disease. The human nervous system and brain contain large amounts of polyunsaturated fatty acids, and these are essential for the development and function of the brain. These omega-3 and omega-6 fatty acids occur in high quantities in just a few foods, such as fat fish. Our bodies can also produce these important fatty acids themselves from certain vegetable oils. In a new study led by researchers at Uppsala University in Sweden and published April 12, 2012 in The American Journal of Human Genetics, scientists have investigated the genes for the two key enzymes that are needed to produce omega-3 and omega-6 fatty acids from vegetable oils. They have found that humans have a unique genetic variant that leads to increased production. This genetic adaptation for high production of omega-3 and omega-6 fatty acids is found only in humans, and not in our living primate relatives chimpanzees, gorillas, and rhesus monkeys. Neanderthals or Denisovans, another type of extinct hominin species, also did not have this genetic variant. It appeared some 300,000 years ago in the evolutionary line that led to modern humans. This genetic adaptation for more efficient omega-3 and omega-6 production from vegetable oils developed in Africa and has probably been an important factor for human survival in environments with limited dietary access to fatty acids.

Biomarker Family Found for Chemo-Resistant Breast Cancers

Biomarkers that could help predict resistance to chemotherapy in breast cancer patients have been identified by researchers from the University of Hull, UK. The researchers found a family of proteins to be twice as prevalent in clinical samples obtained from breast cancer patients who were resistant to chemotherapy than in samples from patients who were successfully treated. Chemotherapy resistance is a major problem for some types of breast cancer and many patients undergo treatment that does not work, delaying other more suitable treatments and subjecting the patient to adverse side effects in the process. Published online on April 3, 2012 in the Journal of Proteomics, the Hull research identifies a number of potential biomarkers associated with resistance to common chemotherapy drugs, including epirubicin and docetaxel. Lead researcher Dr. Lynn Cawkwell says, "A major goal in cancer research is to be able to predict the response of a patient to chemotherapy. Unfortunately, a reliable test has not yet been developed to achieve this. We hope our work can help to bring us a step closer. Most of my work uses clinical samples instead of cell lines, thanks to the links I have with oncologists and surgeons at Castle Hill Hospital in Hull. Studying clinical samples gives a more accurate representation of what is relevant in real-life diseases." The project used two high-throughput processes to screen clinical samples of breast tumour tissue. One screening method using antibodies identified 38 proteins that were twice as prevalent in samples from patients who were resistant to chemotherapy than in samples from those who were successfully treated. The other screening method used mass spectrometry and uncovered 57 potential biomarkers, of which 5 belong to the 14-3-3 protein family.