We transfected p53-restored p53LSL/LSL MEFs with a pool of ASOs to deplete Pint expression or with a non-targeting ASO as control, then treated the cells with doxorubicin to induce DNA damage, and extracted total RNA for microarray analysis in triplicate. is known about the role that lincRNAs play in this pathway. Results Here we characterize a lincRNA named Pint (p53 induced noncoding transcript). We show that Pint is a ubiquitously expressed lincRNA that is finely regulated by p53. In mouse cells, Pint promotes cell proliferation and survival by regulating the expression of genes of the TGF-, MAPK and p53 pathways. Pint is a nuclear lincRNA that directly interacts with the Polycomb repressive complex 2 (PRC2), and is required for PRC2 targeting of specific genes for H3K27 tri-methylation and repression. Furthermore, Pint functional activity is highly dependent on PRC2 expression. Doxazosin mesylate We have also identified Pint human ortholog (PINT), which presents suggestive analogies with the murine lincRNA. PINT is similarly regulated by p53, and its expression significantly correlates with the same cellular pathways as the mouse ortholog, including the p53 pathway. Interestingly, PINT is downregulated in colon primary tumors, while its overexpression inhibits the proliferation of tumor cells, suggesting a possible role as tumor suppressor. Conclusions Our results reveal a p53 autoregulatory negative mechanism where a lincRNA connects p53 activation with epigenetic silencing by PRC2. Additionally, we show analogies and differences between the murine and human orthologs, identifying a novel tumor suppressor candidate lincRNA. Keywords: lincRNA, non-coding RNA, p53, gene regulation, Polycomb repressive complex 2 Background How cells coordinate and integrate information to produce adequate gene-expression output is still an unsolved question with important implications for biology and health. Even the slightest perturbation of cellular networks can affect homeostasis and lead to cell transformation. Of these cellular networks, the p53 pathway is possibly the most relevant for preservation of cellular homeostasis. The transcription factor p53 is located at the core of a complex wiring of signaling pathways, and it has been proposed as the master regulator of cell fate. The importance of the tumor suppressing functions of p53 is shown by its high mutation frequency in cancers and by the highly tumorigenic phenotype of p53 null mice . We and others have shown that long intergenic non-coding RNAs (lincRNAs) Doxazosin mesylate are part of the p53 transcriptional network [2-4]. LincRNAs are intergenic transcripts longer than 200 nucleotides that lack functional open reading frames (ORFs). Although thousands of lincRNAs exist, only a relatively small number have been studied in some depth, indicating that lincRNAs have roles in numerous physiological processes that involve gene regulation [5,6]. Many of these lincRNAs have been shown to act as molecular scaffolds that hold and guide chromatin complexes [7-9]. In particular, several lincRNAs have been found to be associated with the Polycomb repressive complex 2 (PRC2) in a number of biological contexts, modulating PRC2-specific targeting of genes [8,10,11]. PRC2 is composed of three core components: Suppressor of zeste 12 (Suz12), Embryonic Ectoderm Development (EED), and the H3K27 histone methyl transferase Enhancer of zeste homolog 2 (Ezh2). PRC2 represses gene expression by catalyzing H3K27 tri-methylation and modulating chromatin structure , and is closely linked with the aberrant proliferation of Doxazosin mesylate cancer cells. For instance, the Suz12 subunit is overexpressed in colon and breast cancers , and Ezh2 is upregulated in a number of tumors, including Hodgkin lymphoma, prostate cancer, and breast cancer [14,15]. Moreover, Ezh2 expression is associated with poor prognosis, and is an indication of the metastatic potential of a tumor [15,16]. Similarly, alterations in expression of lincRNAs in cancer have been reported, implicating lincRNAs as possible attractive therapeutic targets [17,18]. In a previous work. we used mouse cell lines combined with custom microarrays to monitor the differential expression of lincRNAs, and found that p53 specifically activated several lincRNAs. We characterized one of them, lincRNA-p21, which was found to function like a transcriptional repressor . However, the contribution of lincRNAs to p53 biology and to malignancy still remains mainly unexplored. Here, we increase this knowledge by characterizing Pint. We display that Pint is definitely a ubiquitously indicated mouse lincRNA that is Rabbit polyclonal to ALKBH1 a direct p53 transcriptional target. Pint functions like a positive regulator of cell proliferation and survival, affecting the manifestation of hundreds of genes, including a portion of the p53 transcriptional network. PINT interacts with PRC2 and is required for PRC2 focusing on of specific genes for H3K27 tri-methylation and repression. We also display the PINT human being ortholog is definitely similarly controlled by p53. Interestingly, whereas in normal cells, PINT shows.