Long Noncoding RNA DRAIC Inhibits Prostate Cancer Progression by Interacting with IKK to Inhibit NF-κB Activation

DRAIC is a 1.7 kb spliced long noncodingRNAdownregulated in castration-resistant advanced prostate cancer. Decreased DRAIC expression predicts poor patient outcome in prostate and seven other cancers, while increased DRAIC represses growth of xenografted tumors. Here, we show that cancers with decreased DRAIC expression have increased NF-kappa B target gene expression. DRAIC downregulation increased cell invasion and soft agar colony formation; this was dependent on NF-kappa B activation. DRAIC interacted with subunits of the I kappa B kinase (IKK) complex to inhibit their interaction with each other, the phosphorylation of I kappa B alpha, and the activation of NF-kappa B. These functions of DRAICmapped to the same fragment containing bases 701-905. Thus, DRAIC lncRNA inhibits prostate cancer progression through suppression of NF-kappa B activation by interfering with IKK activity.