RAR/RXR

Retinoic acid receptors (RARs) are members of the nuclear receptor superfamily of ligand-activated transcription factors. There are three isoforms for RARs, RARα, RARβ and RARγ. RARs mediate both organismal and cellular effects of retinoids. They mainly form heterodimers with retinoid X receptor (RXR) and act as ligand-regulated transcription factors through binding specific retinoic acid (RA) response elements (RAREs) located in target genes promoters. RARs also have non-genomic effects and activate kinase signaling pathways, which fine-tune the transcription of the RA target genes. The disruption of RA signaling pathways is thought to underlie the etiology of a number of malignancies, including leukemias, skin cancer, head/neck cancer, lung cancer, breast cancer, ovarian cancer, prostate cancer, renal cell carcinoma, pancreatic cancer, liver cancer, glioblastoma and neuroblastoma.