Differential expression of MEN2 versus VHL human Pheochromocytomas

This study utilized oligonucleotide microarrays to examine gene expression profiles in pheochromocytomas from 23 patients; 11 VHL tumors and 12 MEN2 tumors. RNA was extracted and linearly amplified once, then dye-labeled and co-hybridized to a microarray with over 34,000 oligos representing more than 25,000 unique human genes. In validation of our strategy, many genes known to have elevated expression in MEN2 tumors (e.g., CALM1, CHGB, CABP1and NPY) and several genes known to be specific to VHL (e.g., AQP1) were independently identified by this approach. In addition to known genes, our method has identified several hundred of previously uncharacterized genes that are enriched in the MEN2 or VHL tumors. A 34k expression arrays were generated by printing Oligo nucleotides from the Qiagen HV3 set onto epoxy coated slides (Corning, Inc). Total RNA from pheochrmocytoma tumors or normal adrenals was amplified using an Ambion kit (Cat#1753), labeled with Cy5 and cy3 dyes respectively and hybridized overnight to the oligo chip in a MAUI chamber.