Serial analysis of gene expression in adrenocortical hyperplasia caused by a germline PRKAR1A mutation

Abstract

Context: Adrenocortical tumors have been studied at the molecular genetic and cytogenetic levels, but the gene expression profiles of normal and tumor adrenal tissue have not been extensively investigated. Objective: The objective of this study was to obtain information about transcriptome differences in hyperplastic adrenal cells. Design and Patients: We performed serial analysis of gene expression (SAGE) on control adrenal tissue and primary pigmented nodular adrenocortical disease (PPNAD) tissue from two adolescent female patients. Main Outcome Measure: The main outcome measure was to provide quantitative datasets of the vast majority of the transcripts implicated in normal and pathogenic adrenal functioning. Results: The libraries of 28,705 and 31,278 tags represented 14,846 and 16,698 unique mRNAs from the control and PPNAD tissue, respectively. A total of 842 tags from the two libraries did not match any known sequences. We found 127 tags, including 70 no-match tags, to be expressed almost exclusively in control and/or PPNAD adrenals and to be absent or very rare in other human tissues. Examples of well-characterized genes expressed at significantly higher levels in PPNAD included steroidogenic acute regulator, chromogranin A, and those coding for the steroidogenic enzymes P450 cytochromes CYP17A1 and CYP21A2. Pathway analysis revealed Wnt signaling as the most up-regulated in PPNAD. These data were confirmed for selected genes by quantitative RT-PCR and/or immunohistochemistry. Conclusions: This study was the first of its kind for adrenal tissue and provides important information about the adrenal transcriptome and aberrant signaling in an inherited form of adrenocortical hyperplasia. Copyright © 2006 by The Endocrine Society.