Microarray analysis of the effects of elevated cAMP in differentiating osteoblasts (1013.6)

McCune‐Albright Syndrome (MAS) is an acquired genetic disorder caused by a mutation in Gs alpha at Arg201 that inhibits GTP hydrolysis, constitutively activating the protein and resulting in elevated levels of basal cAMP in the affected cells. A major pathological feature of MAS is polyostotic fibrous dysplasia of bone (FD), a finding for which very little effective therapy exists. In an effort to identify novel potential drug targets to treat FD, we utilized a human fetal osteoblast cell line, hFOB1.19 (ATCC) that proliferates at 33C and differentiates into mature osteoblasts at 39C. We treated cells with the fungal metabolite forskolin at its EC 50 concentration for elevating cAMP in these cells, and then either maintained the cells at 33C or shifted them to the differentiation conditions for 24 hours. Total RNA was collected and analyzed for levels of gene expression using an Illumina HT12 bead chip. Pairwise analysis of changes in gene expression identified 370 genes that were aberrantly expressed during differentiation in the presence of elevated cAMP. Twenty‐eight genes with known functions in osteoblast biology and/or differentiation were further analyzed by RT‐PCR to confirm the expression changes seen in the microarray assay. Grant Funding Source : Supported by NIH grant 1R15ED020190‐01