Scientists have identified a new factor that is necessary for the development of many forms of medulloblastoma, the most common type of malignant childhood brain cancer.
Huda Y. Zoghbi from Howard Hughes Medical Institute (HHMI) and colleagues at Baylor College of Medicine prevented medulloblastoma from developing in mice by shutting down production of the protein Atoh1 in susceptible brain cells. The findings suggest Atoh1 may be a new target for medulloblastoma treatment.
“When we cloned the gene for Atoh1 in 1996, we had no clue that it had any medical relevance. Now we know that it’s critical for many medical issues, the most recent one being this common childhood cancer,” said Zoghbi, a neuroscientist and neurologist. Atoh1 (also known as Math1) is a transcription factor that works in the nuclei of cells to keep certain genes switched on. It is evolutionarily ancient, appearing in slightly varying forms in various species, from fruit flies to humans. In cells where Atoh1 is active, it seems to be switched on only during foetal development, when cells proliferate rapidly to fill out the various parts of the nervous system.
However, in the region of the brain known as the cerebellum, Atoh1 is active after birth in the fast—dividing granule neuron precursor (GNPs) cells that eventually stop dividing and become mature granule neurons. “The cerebellar granule neurons are unique in that most of their development happens after birth, both in mice and humans,” Zoghbi said.
The study has been reported in the December 4, 2009, issue of Science.