The human lncRNA LINC-PINT inhibits tumor cell migration through a highly conserved sequence element

It is now obvious that the majority of cellular transcripts do not code for proteins, and a significant subset of them are long noncoding RNAs (lncRNAs). Many lncRNAs show aberrant expression in cancer, and some of them have been linked to cellular transformation. However, the underlying mechanisms remain poorly understood. Here we characterize the function of the p53-regulated human lncRNA LINC-PINT in cancer. We found that LINC-PINT acts as tumor suppressor lncRNA. Its expression is downregulated in multiple types of cancer and correlates with good prognosis in lung adenocarcinoma. LINC-PINT inhibits the migration capacity and invasive phenotype of cancer cells in vitro and in vivo, and it does so by repressing a proinvasion gene signature in a PRC2-dependent manner. By applying cross-species conservation analysis combined with functional experimental validations we found that the function of LINC-PINT is highly dependent on a short sequence conserved across mammals, sequence that mediates the interaction with PRC2. We propose that LINC-PINT may function as a molecular exchanger that provides PRC2 to active gene promoters for their silencing, mechanisms that could be shared by other PRC2-interacting lncRNAs. We analyzed gene expression in colon adenocarcinoma HCT116 cell line vs LINC-PINT overexpressing HCT116 using the Affymetrix Human Gene 2.0 ST platform. Three techinical replicates were performed per condition.