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.

How stimulating! A new way to repair broken bones

For those of us who live in earthquake country the recent devastating quakes in Nepal are a reminder, as if we needed one, of the danger and damage these temblors can cause. Many of those injured in the quake suffered severe bone injuries – broken legs, crushed limbs etc. Repairing those injuries is going to take time and expert medical care. But now a new discovery is opening up the possibility of repairing injuries like this, even regenerating the broken bones, in a more efficient and effective way.

shutterstock_18578173A study published in Scientific Reports  shows that it is possible to regrow bone tissue using protein signals from stem cells. Even more importantly is that this new bone tissue seems to be just as effective, in terms of the quantity and quality of the bone created, as the current methods.

In a news release senior author Todd McDevitt, Ph.D., said this shows we might not even need whole stem cells to regenerate damaged tissue:

“This proof-of-principle work establishes a novel bone formation therapy that exploits the regenerative potential of stem cells. With this technique we can produce new tissue that is completely stem cell-derived and that performs similarly with the gold standard in the field.”

McDevitt – who is now at the Gladstone Institutes thanks to a research leadership award from CIRM  – extracted the proteins that stem cells produce to help regenerate damaged tissues. They then isolated the particular factors they needed to help regenerate bones, in this case bone morphogenetic protein or BMP. That BMP was then transplanted into mice to stimulate bone growth. And it worked.

While this compares favorably to current methods of regenerating or repairing damaged bones it has a few advantages. Current methods rely on getting bones from cadavers and grinding them up to get the growth factors needed to stimulate bone growth. But bones from cadavers can often be in short supply and the quality is highly variable.

As McDevitt says:

“These limitations motivate the need for more consistent and reproducible source material for tissue regeneration. As a renewable resource that is both scalable and consistent in manufacturing, pluripotent stem cells are an ideal solution.”

He says the next step is to build on this research, and try to find ways to make this method even more efficient. If he succeeds he says it could open up new ways of treating devastating injuries such as those sustained by soldiers in battle, or by earthquake victims.