Since very little is known about the biology of diffuse brainstem glioma, the goal of this protocol is to undertake a systematic analysis of DNA abnormalities, and of RNA and protein expression in prospectively collected fresh-frozen and fixed tumor samples and correspondent normal tissue from patients affected with this tumor.
OBJECTIVES:
- Perform genome-wide analysis of DNA gains and losses and RNA expression in tumor samples and normal tissue from patients with diffuse brain stem glioma.
- Identify regions of genomic gain or loss using either array comparative genomic hybridization or single nucleotide polymorphism arrays.
- Investigate genome-wide expression patterns of RNA derived from tumor samples and normal tissue from these patients via Affymetrix gene expression profiling.
- Validate the results of the genome-wide analysis by conducting further evaluation of candidate genes or by investigating the expression of relevant gene products at the RNA and protein levels.
- Perform analysis of mutations in candidate tumor-suppressor genes and oncogenes (including whole genome sequencing studies) using direct sequence analysis of tumor DNA and confirm the tumor-specific nature of these mutations by analyzing the correspondent constitutional DNA.
- Confirm genomic gains or losses identified by means of fluorescence in situ hybridization (FISH) performed on tissue microarray using non-neoplastic brain tissue from each patient as control when available.
- Explore protein expression patterns identified by immunohistochemistry or western blot and compare them to normal brain stem tissue.
- To obtain a follow-up (questionnaire and/or telephone interview) after autopsy with parent(s), legal guardian(s), or family members of research participants in the United States to assess aspects associated with this procedure, including potential benefits and drawbacks