A sinister brain tumor that claims the lives of every affected child may now be stopped with a new molecule drug.
The brain tumor is known as diffuse intrinsic pontine glioma (DIPG), and it affects about 300 children every year in the US. The tumor is located in the pons of the brain, a part of the brainstem that relays messages from the forebrain to the cerebellum. “This tumor kills every single kid who gets DIPG within one year. No one survives,” said Andrea Piunti, underscoring the extremely aggressive nature of this tumor. Piunti is the study’s first author who is a postdoctoral fellow at the Northwestern University Feinberg School of Medicine.
Previously, the same lab identified a potential pathway mutation behind DIPG. In particular, they published that a mutation in the histone H3 molecule may be driving the growth of DIPG in fruit fly models. In follow-up work, the team demonstrated that a drug that corrected the effects of the mutation was able to prolong survival in mice by 20 days.
Now, the team sought to demonstrate the effects of the drug in DIPG patient-derived tumors in mice when directly injected in the brainstem. The drug is a BET bromodomain inhibitor, which prevent binding of bromodomain proteins to the mutant histone protein. These molecules are already used in a variety of other clinical trials as potential cancer therapies.
The team observed that treatment with the drug halted the tumor growth in mice. Furthermore, the drug triggered differentiation in the tumor cells, which also contributed to the reduction in tumor growth. Mice treated with BET inhibitor had significantly extended survival as compared to untreated mice.
“To the best of our knowledge, this is the most effective molecule so far in treating this tumor,” said Dr. Ali Shilatifard, the study’s senior author. “Every other therapy that has been tried so far has failed.”
Because BET inhibitors are available and have been used to treat leukemia, the researchers hope to apply it to clinical trials for DIPG patients next. Additionally, the team postulated that the BET inhibitor may be combined with other promising DIPG therapies, such as histone deacetylase (HDAC) inhibitors, with positive synergistic effects.
Additional sources: Northwestern University