Neuro Oncol 2016 06 10;18(6):764-78. Epub 2016 Jan 10.
Children's Hospital and Swabian Children's Cancer Center, Augsburg, Germany (M.C.F.); Department of Pathology and Laboratory Medicine, Children's Hospital Los Angeles, Los Angeles, California (J.A.B.); INSERM U830, Laboratory of Genetics and Biology of Cancers, and Department of Pediatric Oncology, Curie Institute, Paris, France (F.B.); Comprehensive Cancer Center and Department of Oncology, St Jude Children's Research Hospital, Memphis, Tennessee (C.W.M.R.); Department of Pediatric Oncology, Dana-Farber Cancer Institute, Boston, Massachusetts (S.N.C.); Division of Hematology/Oncology, Boston Children's Hospital, Boston, Massachusetts (S.N.C.); Department of Pediatrics, Harvard Medical School, Boston, Massachusetts (S.N.C.).
Atypical teratoid/rhabdoid tumor (AT/RT) is the most common malignant CNS tumor of children below 6 months of age. The majority of AT/RTs demonstrate genomic alterations in SMARCB1 (INI1, SNF5, BAF47) or, to a lesser extent, SMARCA4 (BRG1) of the SWItch/sucrose nonfermentable chromatin remodeling complex. Recent transcription and methylation profiling studies suggest the existence of molecular subgroups. Thus, at the root of these seemingly enigmatic tumors lies a network of factors related to epigenetic regulation, which is not yet completely understood. While conventional-type chemotherapy may have significant survival benefit for certain patients, it remains to be determined which patients will eventually prove resistant to chemotherapy and thus need novel therapeutic strategies. Elucidation of the molecular consequences of a disturbed epigenome has led to the identification of a series of transduction cascades, which may be targeted for therapy. Among these are the pathways of cyclin D1/cyclin-dependent kinases 4 and 6, Hedgehog/GLI1, Wnt/ß-catenin, enhancer of zeste homolog 2, and aurora kinase A, among others. Compounds specifically targeting these pathways or agents that alter the epigenetic state of the cell are currently being evaluated in preclinical settings and in experimental clinical trials for AT/RT.