In conjunction with CD15, proliferating CD24+/CD15+ granule cell precursors (GCPs) were identified as a TIC population in Ptch1 deleted medulloblastoma.
These studies validate the therapeutic efficacy of pan PI-3K inhibitors in the treatment of CD15+ TPC dependent medulloblastoma and suggest a sequential combination of PI-3K inhibitors and chemotherapy will have augmented efficacy in the treatment of this disease.
Previous reports have implicated CD133-expressing cells as CSCs in brain tumors, while those expressing CD15 have been shown to propagate medulloblastoma.
Furthermore, the cluster of differention (CD) carbohydrate antigen CD15, a marker of medulloblastoma tumor-propagating cells, is an additional direct target of miR-199b-5p.