Two items relevant to long COVID

One of the tricky issues in studying in long COVID is: how widely do researchers cast their net? Initial reports acknowledged that people who were hospitalized and in intensive care may take a while to get back on their feet. But the number of people who had SARS-CoV-2 infections and were NOT hospitalized, yet experienced lingering symptoms, may be greater. A recent report from the United Kingdom, published in PLOS Medicine, studied more than Read more

All your environmental chemicals belong in the exposome

Emory team wanted to develop a standard low-volume approach that would avoid multiple processing steps, which can lead to loss of material, variable recovery, and the potential for Read more

Signature of success for an HIV vaccine?

Efforts to produce a vaccine against HIV/AIDS have been sustained for more than a decade by a single, modest success: the RV144 clinical trial in Thailand, whose results were reported in 2009. Now Emory, Harvard and Case Western Reserve scientists have identified a gene activity signature that may explain why the vaccine regimen in the RV144 study was protective in some individuals, while other HIV vaccine studies were not successful. The researchers think that this signature, Read more

cancer metabolism

Melanoma mutation likes fat for fuel

Cancer cells love glucose, the simple sugar the body uses for energy, so a high-fat, low-carb diet should starve them, right?

Where does this idea come from? Most cancer cells display enhanced glucose uptake, a phenomenon known as the Warburg effect, after 1931 Nobel Prize winner Otto Warburg.

Resurgent interest in exploiting the Warburg effect was described by Sam Apple in NYT Magazine and by Bret Stetka for NPR. High-fat, low-carb “ketogenic” diets are known to be effective against some types of epilepsy, and have also been explored by endurance athletes. Ketogenic diets have been tried as a clinical countermeasure against cancer in a limited way, mainly in brain cancer.

Before everybody gets too excited, let’s think about how particular cancer-driving mutations affect cell metabolism, suggests Winship Cancer Institute researcher Jing Chen. His team’s work in mice suggests that cancers with a common melanoma mutation (BRAF V600E) will grow faster in response to a ketogenic diet. In addition, the Winship researchers found that lipid-lowering agents such as statins curb these cancers’ growth, even in the context of a more normal diet.

The results were published on January 12 in Cell Metabolism.

Caveats: the findings cover just one mutation and need to be tested clinically.

Consumers and cancer patients already get a lot of advice about the right diet to fight cancer, but this research points toward an intriguing concept:  a “precision diet,” tailored to an individual patient’s cancer.  Read more

Posted on by Quinn Eastman in Cancer Leave a comment

Orange lichens are source for potential anticancer drug

An orange pigment found in lichens and rhubarb called parietin may have potential as an anti-cancer drug, scientists at Winship Cancer Institute of Emory University have discovered.

The results were published in Nature Cell Biology on October 19.

Caloplaca_Fenwick

Parietin, shown to have anticancer activity in the laboratory, is a dominant pigment in Caloplaca lichens. Note: this study did not assess the effects of eating lichens or rhubarb. Photo courtesy of www.aphotofungi.com

Parietin, also known as physcion, could slow the growth of and kill human leukemia cells obtained directly from patients, without obvious toxicity to human blood cells, the authors report. The pigment could also inhibit the growth of human cancer cell lines, derived from lung and head and neck tumors, when grafted into mice.

A team of researchers led by Jing Chen, PhD, discovered the properties of parietin because they were looking for inhibitors for the metabolic enzyme 6PGD (6-phosphogluconate dehydrogenase). 6PGD is part of the pentose phosphate pathway, which supplies cellular building blocks for rapid growth. Researchers have already found 6PGD enzyme activity increased in several types of cancer cells.

“This is part of the Warburg effect, the distortion of cancer cells’ metabolism,” says Chen, professor of hematology and medical oncology at Emory University School of Medicine and Winship Cancer Institute. “We found that 6PGD is an important metabolic branch point in several types of cancer cells.” Read more

Posted on by Quinn Eastman in Cancer Leave a comment

Potential anticancer drugs from humble sources

Jing Chen and colleagues at Winship Cancer Institute recently published a paper in Molecular Cell. Most of the paper deals with a metabolic enzyme, 6PGD (6-phosphogluconate dehydrogenase), and how it is more active in cancer cells.

Rhubarb_Flower

Rheum palmatum/Chinese rhubarb/da-huang

Tucked in at the end is a note that an inhibitor of 6GPD with an odd name, physcion, has anticancer activity in Chen’s team’s hands. Physcion, also known as parietin, is an orange-yellow pigment extractable from lichens and Chinese rhubarb that has been employed as an anti-mildew agent.

Probing cancer cells’ warped metabolism is a promising approach, for both drug discovery and finding effective ways to combine existing drugs, because of the Warburg effect: cancer cells’ tendency to suck up lots of sugar and use it in energy-inefficient ways. Read more

Posted on by Quinn Eastman in Cancer 1 Comment