New model unlocks clues to treating deadly childhood cancer

CIRM-funded research at Sanford Burnham Prebys Medical Discovery Institute in San Diego is identifying compounds that could be used to help children battling a deadly brain cancer.

The cancer is choroid plexus carcinoma (CPC), a rare brain tumor that occurs mainly in children. As it grows the tumor can affect nearby parts of the brain resulting in nausea, vomiting and headaches.

Treatment involves surgery to remove the tumor followed by chemotherapy and radiation. However, many of the children are too young to undergo radiation and only around 40 percent are still alive five years after being diagnosed. Even those who do survive often experience life-long consequences such as developmental disabilities.

One obstacle to developing better therapies has been the lack of a good animal model to enhance our understanding of the disease. That’s where this later research, published in the journal Cancer Research, comes in.

The team at Sanford Burnham developed a new mouse model, by knocking out p53, a gene known to suppress tumor formation, and activating a gene called Myc, which is known to cause cancer.  

Robert Wechsler-Reya

In a news release, Robert Wechsler-Reya, the senior author of the paper, says this new model mirrors the way CPC grows and develops in humans.

“This model is a valuable tool that will increase our understanding of the biology of the cancer and allow us to identify and test novel approaches to therapy. This advance brings us one step closer to a future where every child survives—and thrives—after diagnosis with CPC.”

As proof of that the team tested nearly 8,000 compounds against the mouse tumor cells, to see if they could help stop or slow the progression of the disease. They identified three that showed potential of not just stopping the cancer, but of also not harming healthy surrounding cells.

“These compounds are promising, much-needed leads in the quest for an effective CPC treatment,” says Wechsler-Reya. “Our laboratory plans to evaluate these and additional compounds that can effectively treat this cancer.”

Targeted treatment for pediatric brain tumors shows promising results

Image of medulloblastoma

Imagine sitting in the doctor’s office and being told the heartbreaking news that your child has been diagnosed with a malignant brain tumor. As one might expect, the doctor states that the most effective treatment option is typically a combination of chemotherapy and radiation. However, the doctor reveals that there are additional risks to take into account that apply to children. Since children’s tiny bodies are still growing and developing, chemotherapy and radiation can cause long-term side effects such as intellectual disabilities. As a parent, it is painful enough to have to watch a child go through chemotherapy and radiation without adding permanent damage into the fold.

Sadly, this scenario is not unique. Medulloblastoma is the most prevalent form of a pediatric brain tumor with more than 350 children diagnosed with cancer each year. There are four distinct subtypes of medulloblastoma, with the deadliest being known as Group 3.

Researchers at Sanford Burnham Prebys Medical Discovery Institute (SBP) are trying to minimize the collateral damage by finding personalized treatments that reduce side effects while remaining effective. Scientists at SBP are working with an inhibitor known as LSD1 that specifically targets Group 3 medulloblastoma in a mouse model. The study, published in Nature Communications, showed that the drug dramatically decreased the size of tumors grown under the mouse’s skin by shrinking the cancer by more than 80 percent. This suggested that it could also be effective against patients’ tumors if it could be delivered to the brain. The LSD1 inhibitor has shown promise in clinical trials, where it has been tested for treating other types of cancer.

According to Robert Wechsler-Reya, Ph.D., senior author of the paper and director of the Tumor Initiation and Maintenance Program at SBP: “Our lab is working to understand the genetic pathways that drive medulloblastoma so we can find better ways to intervene and treat tumors. This study shows that a personalized treatment based upon a patient’s specific tumor type might be within our reach.”

Dr. Wechsler-Reya’s work on medulloblastoma was, in part, funded by the CIRM (LA1-01747) in the form of a Research Leadership Award for $5,226,049.