Cellular fuel gauge may hold the key to restricting cancer growth
|
|
Researchers at McGill University have discovered that a key regulator of energy metabolism in cancer cells known as the AMP-activated protein kinase (AMPK) may play a crucial role in restricting cancer cell growth. AMPK acts as a “fuel gauge” in cells; AMPK is turned on when it senses changes in energy levels, and helps to change metabolism when energy levels are low, such as during exercise or when fasting. The researchers found that AMPK also regulates cancer cell metabolism and can restrict cancer cell growth.
The discovery was made by Russell (Rusty) Jones, an assistant professor at McGill’s Goodman Cancer Research Centre and the Department of Physiology, Faculty of Medicine. Jones along with his team is the first to show that AMPK can act as a tumour suppressor in animals. The research will be published December 27 in the journal Cell Metabolism.
“Cancer is a disease in which cells lose their normal restraints on growth and start to divide uncontrollably. But, in order for cells to grow quickly they need enough energy to complete the task,” Jones explained. “AMPK acts like the fuel gauge in your car – it lets the body know when energy levels are low, and stops cell growth until there is enough gas in the tank. We wanted to see if this fuel gauge could affect the development and progression of cancer. We found that mice lacking AMPK developed tumours faster, suggesting that AMPK is important for keeping tumour development in check, at least for some types of cancer.” For this study, Jones’ team focused specifically on a type of blood cancer known as lymphoma. They discovered that the protein Myc, which is activated in more than half of all cancers, could promote lymphoma more rapidly when mice were deficient for AMPK.
Steroid hormone receptor prefers working alone to shut off immune system genes
|
|
Researchers at Emory University School of Medicine have obtained a detailed molecular picture that shows how glucocorticoid hormones shut off key immune system genes.
The finding could help guide drug discovery efforts aimed at finding new anti-inflammatory drugs with fewer side effects.
The results are scheduled for publication Sunday, Dec. 9 by the journal Nature Structural & Molecular Biology.
Synthetic glucocorticoid hormones - for example, prednisone and dexamethasone - are widely used to treat conditions such as allergies, asthma, autoimmune diseases and cancer. They mimic the action of the natural hormone cortisol, which is involved in the response to stress and in regulating metabolism and the immune system. For this reason, synthetic glucocorticoids have a variety of severe side effects such as increased blood sugar and reduced bone density.
Glowing fish shed light on metabolism
|
|
A tiny, translucent zebrafish that glows green when its liver makes glucose has helped an international team of researchers identify a compound that regulates whole-body metabolism and appears to protect obese mice from signs of metabolic disorders.
Led by scientists at the University of California, San Francisco (UCSF), the work demonstrates how a fish smaller than a grain of rice can help screen for drugs to help control obesity, type 2 diabetes and other metabolic disorders, which affect a rising 34 percent of American adults and are major risk factors for cardiovascular disease.
Described this week in the journal Nature Chemical Biology, the new compound emerged from a panel of 2,400 medications and drug-like compounds tested in the zebrafish. The test was designed to identify key regulators of “fasting metabolism”- a state most people face every day after the lingering remnants of their long-digested meals pass slowly down their digestive tract.
Fasting metabolism is the body’s way of fulfilling its energy needs between meals by turning to fat and other stored sources. It involves a carefully balanced and coordinated cascade of reactions that see numerous genes in various tissues kick into action and do things like burn fat.
