The regulatory protein FoxM1 is essential for the continued growth of the most frequent class of malignant childhood brain tumor—medulloblastoma—and is significantly and negatively correlated with survival, making it a useful prognostic marker.
These discoveries were made by a research team based at the Center for Neuropathology and Prion Research at Ludwig-Maximilians-Universität München in Munich, Germany, and led by Dr. Ulrich Schüller. Already armed with the knowledge that FoxM1 expression is required for the growth of multiple cancer types, Schüller’s team sought to determine whether the protein plays a role in supporting the growth of medulloblastoma and if so, whether it might serve as a therapeutic target.
The group evaluated FoxM1 expression in two independent series of human medulloblastoma samples, using immunohistochemistry in 43 samples and gene expression arrays in 193. They found that FoxM1 was highly expressed in all subtypes of medulloblastoma, and that expression levels of the protein significantly correlated with unfavorable clinical outcomes, rendering it an independent prognostic marker.
Schüller and colleagues further learned that exposing FoxM1 levels in tumor cells to the antibiotic siomycin A reduced those levels; the antibiotic also inhibited tumor growth. As the researchers noted in Clinical Cancer Research, if further work on laboratory cell cultures as well as living organisms confirms these results, siomycin could turn out to be an effective drug for the treatment of medulloblastoma.