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

chemotherapy

To fight cancer, mix harmless reovirus with ‘red devil’

A recent paper in Journal of Virology mixes tried-and-true cancer-fighting tactics with the exotic. Sort of a peanut-butter-and-chocolate story, but definitely not tasty!

The tried and true is doxorubicin (Adriamycin), the notorious ‘red devil’ chemotherapy drug, which has been around for decades. On the exotic side, we have oncolytic viruses – viruses retuned to attack cancer cells more than healthy cells. This idea finally made it to FDA approval in 2015 in the form of a re-engineered herpes virus directed against melanoma.

Bernardo Mainou’s lab in the Department of Pediatrics is combining both of these approaches together. He and his team are looking to supercharge reoviruses, a mostly harmless type of virus that has been adapted into an anticancer agent. A Canadian company has brought its reovirus forward into several cancer clinical trials, but its product has not gotten to the finish line.

In the JVI paper, graduate students Roxana Rodriguez-Stewart, Jameson Berry and their colleagues infected triple-negative breast cancer cells with a variety of reoviruses, in an effort to select for those that replicate better in those cells. They also looked for drugs that enhance viral infection of those cells, and landed on doxorubicin and related drugs. Doxorubicin is part of a class of anticancer drugs that inhibit topoisomerases, enzymes that unwind DNA as part of the process of replication.

Yesterday at the GDBBS graduate research symposium, Berry gave a talk about the next step: attaching the souped-up reovirus to doxorubicin.

Three varieties of reovirus were grown together in breast cancer cells to select for efficient replication. 

 

 

 

 

Posted on by Quinn Eastman in Cancer Leave a comment

Overcoming cisplatin resistance

Despite being studied for decades, the chemotherapy drug cisplatin is revealing new aspects of how it works. Researchers at Winship Cancer Institute of Emory University have identified an enzyme responsible for making tumors and cancer cell lines resistant to cisplatin, along with an experimental drug that targets that enzyme.

The results were published on July 19 in Cancer Cell.

Winship researcher Sumin Kang, PhD

Cisplatin is a DNA-damaging agent used in standard treatment for lung, head and neck, ovarian, and testicular cancers. It has a simple structure, grabbing DNA with its metallic (platinum) arms to form crosslinks. It used to be known as “cis-flatten” because of its nausea-inducing side effects. The experimental drug, lestaurtinib, has already been tested in clinical studies in combination with other chemotherapy drugs, which means it could easily go into trials against tumors displaying cisplatin resistance.

Sumin Kang, PhD, and colleagues at Winship decided to look for enzymes whose activity was necessary for cancer cells to withstand cisplatin treatment. They chose kinases, enzymes that often control some aspect of cell growth and are have plenty of existing drugs targeting them. The researchers found that in combination with a sub-lethal amount of cisplatin, “knocking down” the activity of the kinase MAST1 kills a cell. But how does that combination work?

Read more

Posted on by Quinn Eastman in Cancer Leave a comment

SUMO wrestling enzyme important in DNA repair

The DNA in our cells is constantly being damaged by heat, radiation and other environmental stresses, and the enzyme systems that repair DNA are critical for life. A particularly toxic form of damage is the covalent attachment of a protein to DNA, which can be triggered by radiation or by anticancer drugs.

Keith Wilkinson, PhD

Emory biochemist Keith Wilkinson and colleagues have a paper this week in the journal eLife probing how a yeast protein called Wss1 is involved in repairing DNA-protein crosslinks. The researchers show how Wss1 wrestles with a protein tag called SUMO on the site of the DNA damage, and how Wss1 and SUMO are involved in the cleanup process.

Three interesting things about this paper:

*The paper grew out of first author Maxim Balakirev’s sabbatical with Wilkinson at Emory. Balakirev’s home base is at the CEA (Alternative Energy and Atomic Energy Commission) in Grenoble, France.

* Since many cancer chemotherapy drugs induce protein-DNA cross links, an inhibitor of cross link repair could enhance those drugs’ effectiveness. On the other side of the coin, mutations in a human gene called Spartan, whose sequence looks similar to Wss1’s, cause premature aging and susceptibility to liver cancer. Whether the Spartan-encoded protein has the same biochemical activity as Wss1 is not yet clear.

*SUMO stands for “small ubiquitin-like modifier”. The eLife digest has an elegant explanation of what’s happening: Read more

Posted on by Quinn Eastman in Cancer Leave a comment

Heated, targeted chemotherapy helps abdominal cancers

Cancer of the colon, ovaries, appendix or other organs within the abdomen often spreads to the lining of the abdominal cavity. Experts call this condition peritoneal surface malignancy. Until recently, treatment options for this form of cancer only provided relief from symptoms.

Emory University Hospital is one of a few facilities nationwide to utilize a new combination therapy to slow or prevent recurrence of this cancer. Hyperthermic intraperitoneal chemoperfusion (HIPEC) is a procedure done immediately following surgery that delivers heated chemotherapy directly into the abdominal cavity where it can penetrate cancerous tissue. Heat at 42 C (107 F) destroys cancer cells and enhances the power of chemotherapy.

The term “intraperitoneal” means that the treatment is delivered to the abdominal cavity. “Hyperthermic chemoperfusion” means that the solution containing chemotherapy is heated to a temperature greater than normal body temperature.

Charles Staley, MD, chief of surgical oncology at the Emory Winship Cancer Institute, says by bathing the abdomen with heated chemotherapy immediately following surgery doctors can administer a higher dose of medication than would normally be tolerated by a patient if given intravenously – the traditional way chemotherapy is administered.

During surgery, Staley removes all visible tumors throughout the abdomen, a procedure known as cytoreductive surgery. Following surgery, while still in the operating room, Staley administers the new treatment, which takes about two hours. Recent studies show improved prognosis in patients treated with HIPEC after the cytoreductive surgery.

Illustration of heated chemo therapy

Illustration of heated, targeted chemotherapy

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