Warren symposium follows legacy of geneticist giant

If we want to understand how the brain creates memories, and how genetic disorders distort the brain’s machinery, then the fragile X gene is an ideal place to start. That’s why the Stephen T. Warren Memorial Symposium, taking place November 28-29 at Emory, will be a significant event for those interested in neuroscience and genetics. Stephen T. Warren, 1953-2021 Warren, the founding chair of Emory’s Department of Human Genetics, led an international team that discovered Read more

Mutations in V-ATPase proton pump implicated in epilepsy syndrome

Why and how disrupting V-ATPase function leads to epilepsy, researchers are just starting to figure Read more

Tracing the start of COVID-19 in GA

At a time when COVID-19 appears to be receding in much of Georgia, it’s worth revisiting the start of the pandemic in early 2020. Emory virologist Anne Piantadosi and colleagues have a paper in Viral Evolution on the earliest SARS-CoV-2 genetic sequences detected in Georgia. Analyzing relationships between those virus sequences and samples from other states and countries can give us an idea about where the first COVID-19 infections in Georgia came from. We can draw Read more
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vasculostatin

The body’s anticancer defenses come in a variety of sizes

Sometimes you have to look at the whole picture, big and small.

Sarah Cork, PhD

That was the lesson that emerged from Winship Cancer Institute researcher Erwin Van Meir’s laboratory, highlighted in a recent paper in Oncogene. Van Meir’s team has been studying vasculostatin, a secreted protein that inhibits blood vessel growth by tumors (hence the name). Vasculostatin was discovered by Balveen Kaur, now at Ohio State, while she was in Van Meir’s lab.

Van Meir and his colleagues originally began studying vasculostatin because it is a product of a gene that brain tumors somehow silence or get rid of, and studying the obstacles our bodies throws in cancer’s way may be a good way to learn how to fight it via modern medicine. Eventually, it could form the basis for a treatment to prevent a tumor from attracting new blood vessels.

Vasculostatin is somewhat unique because it is a secreted fragment of a membrane-bound protein, called BAI1. BAI1 has an apparently separate function as an “engulfment receptor,” allowing the recognition and internalization of dying cells.

Most of the secreted vasculostatin is around 40 kilodaltons in size, not 120 as previously thought.

Graduate student Sarah Cork discovered that most of the vasculostatin protein being produced by cells is actually much smaller than what had been originally discovered. She and Van Meir were surprised to find that the smaller, cleaved form of the protein still has potent anti-angiogenic activity.

The researchers were using a technique where a mixture of proteins is separated within a gel by electric current, transferred to a polymer sheet, and probed with antibodies. The large proteins appear at the top and the small proteins at the bottom.

“Previously, we had been running the gels for a long time to detect large protein fragments, so missed out on what was happening with small fragments which run off the gel,” Van Meir says. “We were only looking at the top of the
gel, when the smaller form of vasculostatin was actually much more
abundant as you can see on the picture of a gel run for a shorter time.”

More broadly, Van Meir says that the finding adds to understanding about BAI1’s dual function in the brain and how vasculostatin (big or small) might be used in anticancer therapy.

Posted on February 28, 2012 by Quinn Eastman in Cancer Leave a comment