Targeted Approach Shows Promise in Treating Deadly Pediatric Brain Cancer

An investigational targeted treatment method was able to shrink tumors caused by medulloblastoma, a form of pediatric brain cancer, according to a recent study published in Nature Communications.

Researchers from Sanford Burnham Prebys Medical Discovery Institute (SBP) developed a targeted treatment that works by blocking a protein called lysine demethylase 1 (LSD1) in group 3 medulloblastoma, the deadliest subtype of the disease.

Medulloblastoma is one of the most prevalent malignant brain tumors in children. More than 350 children are diagnosed with the disease each year. Standard treatment usually involves surgery to remove the tumor, followed by chemotherapy and radiation. There is currently a poor prognosis for those diagnosed with medulloblastoma; one-third of patients will succumb to the disease.

Although chemotherapy and radiation can be effective treatments, they carry a risk of adverse effects due to their high toxicity and can lead to long-term complications, particularly for children. The researchers hope the new therapeutic approach could offer an alternative option for children with the disease to avoid toxicity exposure.

“Subjecting a developing child to chemotherapy and radiation of the head and spine can leave devastating long-term effects,” said senior author Robert Wechsler-Reya, PhD, professor and director of the Tumor Initiation and Maintenance Program at SBP and program director of the Joseph Clayes III Research Center for Neuro-Oncology and Genomics at the Rady Children’s Institute for Genomic Medicine. “Some children even become intellectually disabled as a result of the treatment, and aren’t able to go to college, live on their own, or achieve other important milestones.”

According to Dr Wechsler-Reya, the findings indicate that a more personalized treatment approach based upon a patient’s specific tumor type might be within reach.

Previously, the researchers’ work had confirmed that a transcription factor called GFI1 is activated in approximately one-third of group 3 tumors.

“In particular, we identify the epigenetic modifier LSD1 as a critical partner to GTFI1, and we demonstrate that these proteins promote oncogenic transformation in part by inhibiting neuronal differentiation,” the researchers wrote in the study. Because transcription factors are difficult to target therapeutically, the researchers found an epigenetic modifier called LSD1, a protein that interacts with GTF11 and can be more easily targeted.

In a mouse model of GFI1-activated group 3 medulloblastoma, the LSD1 inhibitor dramatically decreased the size of the tumors grown under the mouse’s skin. The study showed that treatment with the LSD1 inhibitor shrank the cancer by more than 80%.

According to the researchers, the next step is developing drug delivery technologies that could carry this drug across the blood-brain barrier to the tumor.

“If these approaches are successful, an LSD1 inhibitor could be a promising targeted therapy for children with GFI1-driven group 3 medulloblastoma,” Dr Wechsler-Reya concluded.

References

Lee C, Rudneva VA, Zapatka M, et al. Lsd1 as a therapeutic target in Gfi1-activated medulloblastoma. Nature Communications. 2019. https://www.nature.com/articles/s41467-018-08269-5#Abs1.

Targeted treatment shrinks deadly pediatric brain tumors [news release]. Sanford Burnham Prebys Medical Discovery Institute. https://www.sbpdiscovery.org/press/targeted-treatment-shrinks-deadly-pediatric-brain-tumors. Accessed January 24, 2019.