Metabolic Protein Launches Sugar Feast That Nurtures Brain Tumors

Researchers at The University of Texas MD Anderson Cancer Center have tracked down a cancer-promoting protein’s pathway into the cell nucleus and discovered how, once there, it fires up a glucose metabolism pathway on which brain tumors thrive.

They also found a vital spot along the protein’s journey that can be attacked with a type of drug not yet deployed against glioblastoma multiforme, the most common and lethal form of brain cancer. Published online by Nature Cell Biology, the paper further illuminates the importance of pyruvate kinase M2 (PKM2) in cancer development and progression.

"PKM2 is very active during infancy, when you want rapid cell growth, and eventually it turns off. Tumor cells turn PKM2 back on - it’s overexpressed in many types of cancer," said Zhimin Lu, M.D., Ph.D., the paper’s senior author and an associate professor in MD Anderson’s Department of Neuro-Oncology.

Lu and colleagues showed earlier this year that PKM2 in the nucleus also activates a variety of genes involved in cell division. The latest paper shows how it triggers aerobic glycolysis, processing glucose into energy, also known as the Warburg effect, upon which many types of solid tumors rely to survive and grow.

"PKM2 must get to the nucleus to activate genes involved in cell proliferation and the Warburg effect," Lu said. "If we can keep it out of the nucleus, we can block both of those cancer-promoting pathways. PKM2 could be an Achilles’ heel for cancer."

By pinpointing the complicated steps necessary for PKM2 to penetrate the nucleus, Lu and colleagues found a potentially druggable target that could keep the protein locked in the cell’s cytoplasm.

(Image Credit: Wikimedia Commons)

Sugar boosts self-control

To boost self-control, gargle sugar water. According to a study co-authored by University of Georgia professor of psychology Leonard Martin published Oct. 22 in Psychological Science, a mouth rinse with glucose improves self-control.

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Scientists announce new treatment for type II diabetes

According to the World Health Organization, there are currently 347 million diabetics worldwide, with 90 percent of those people having type II diabetes specifically. It occurs when fat accumulates in places such as muscles, blood vessels and the heart, causing the cells in those areas to no longer be sufficiently responsive to insulin. This insulin resistance, in turn, causes blood glucose levels to rise to dangerous levels. Ultimately, it can result in things such as heart disease, strokes, blindness, kidney failure, and amputations. Fortunately, however, an international team of scientists has just announced a new way of treating the disease.

Currently, one of the main ways of treating type II diabetes involves switching the patient to a healthier diet and increasing the amount of exercise they get – the disease is most often caused by obesity. Additionally, oral medication can be used to increase insulin production and the body’s sensitivity to it, or to decrease glucose production. For approximately 30 percent of patients, however, such medication ceases to be effective after a few years, and they end up having to receive regular insulin injections.

The new treatment focuses on VEGF-B, a protein within the body that affects how fat is transported and stored. Using an antibody/drug known as 2H10, the scientists were able to block the signaling of VEGF-B in mice and rats, which subsequently kept fat from accumulating in the “wrong” areas of the animals – namely their muscles, blood vessels and hearts.

Researchers have created a new type of biosensor that can detect minute concentrations of glucose in saliva, tears and urine and might be manufactured at low cost because it does not require many processing steps to produce.

"It’s an inherently non-invasive way to estimate glucose content in the body," said Jonathan Claussen, a former Purdue University doctoral student and now a research scientist at the U.S. Naval Research Laboratory. "Because it can detect glucose in the saliva and tears, it’s a platform that might eventually help to eliminate or reduce the frequency of using pinpricks for diabetes testing. We are proving its functionality."

The sensor has three main parts: layers of nanosheets resembling tiny rose petals made of a material called graphene, which is a single-atom-thick film of carbon; platinum nanoparticles; and the enzyme glucose oxidase.