Transcript levels in CCE WT and RARgamma knockout murine embryonic stem cells treated with either all-trans retinoic acid (8 and 24 hr) or with vehicle control. Mus musculus

Retinoic acid receptors (RARs) α, β, and γ heterodimerize with Retinoid X receptors (RXR) α, β, and γ and bind the cis-acting response elements known as RAREs to execute the biological functions of retinoic acid during mammalian development. RARγ mediates the anti-proliferative and apoptotic effects of retinoids in certain tissues and cancer cells, such as melanoma and neuroblastoma cells. Furthermore, ablation of RARγ enhanced the tumor incidence of Ras transformed keratinocytes and was associated with resistance to retinoid mediated growth arrest and apoptosis. We used microarray analysis to identify genes, which upon 8 or 24 hr of treatment with all-trans retinoic acid display differential expression in RARγ knockout (RARγKO) murine embryonic stem cells relative to CCE WT cells. We demonstrate that following RA treatment the majority of inducible transcripts are present at lower levels in RARγKO ES cells compared to WT ES cells. Overall design: Murine embryonic stem cells (WT and RARγKO) were treated with either all-trans retinoic acid (up to 24 hr) or with vehicle control (EtOH).