Cellular retinoic acid binding protein 2 (CRABP2) inhibits tumor growth by two distinct mechanisms

CRABP2 potently suppresses carcinoma cell growth, yet the mechanism(s) that underlie this activity remain incompletely understood. Two distinct functions are known for CRABP2: 1) the classical function of this protein is to directly deliver retinoic acid (RA) to the nuclear retinoic-acid receptorthereby activate gene expression, and 2) in the absence of RA, CRABP2 directly binds to the RNA-binding and stabilizing protein, HuR, and markedly strengthens its interactions with target mRNAs. We used microarray experiments to elucidated genes regulated by HuR and/or CRABP2 in the absence of retinoic acid. Two experiments were preformed: 1) Transcriptome profiles of MCF-7 cells overexpresssing shHuR were compared to control cells, both in the absence of retinoic acid. 2) Transcriptome profiles of MCF-7 cells overexpresssing shCRABP2 were compared to control cells, both in the absence of retinoic acid.