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NEAT1

Long non-coding RNAs (lncRNAs) play a critical role in cancer progression, including in nasopharyngeal carcinoma (NPC). However, it is still poorly understood whether lncRNA regulates epithelial to mesenchymal transition (EMT) and radioresistance of NPC cells. We found that lncRNA NEAT1 was significantly upregulated in NPC cell lines and tissues. Knockdown of NEAT1 could sensitize NPC cells to radiation in vitro. Further investigation found that NEAT1 regulated radioresistance by modulating EMT phenotype. Furthermore, we found that there was reciprocal repression between NEAT1 and miR-204. ZEB1 was identified as a downstream target of miR-204 and NEAT1 upregulated ZEB1 expression by negatively regulating miR-204 expression. Taking together, we proposed that NEAT1 regulated EMT phenotype and radioresistance by modulating the miR-204/ZEB1 axis in NPC.

The pathophysiological function of the forkhead transcription factor FOXN3 remains to be explored. Here we report that FOXN3 is a transcriptional repressor that is physically associated with the SIN3A repressor complex in estrogen receptor-positive (ER+) cells. RNA immunoprecipitation-coupled high-throughput sequencing identified that NEAT1, an estrogen-inducible long noncoding RNA, is required for FOXN3 interactions with the SIN3A complex. ChIP-Seq and deep sequencing of RNA genomic targets revealed that the FOXN3-NEAT1-SIN3A complex represses genes including GATA3 that are critically involved in epithelial-to-mesenchymal transition (EMT). We demonstrated that the FOXN3-NEAT1-SIN3A complex promotes EMT and invasion of breast cancer cells in vitro as well as dissemination and metastasis of breast cancer in vivo. Interestingly, the FOXN3-NEAT1-SIN3A complex transrepresses ER itself, forming a negative-feedback loop in transcription regulation. Elevation of both FOXN3 and NEAT1 expression during breast cancer progression corresponded to diminished GATA3 expression, and high levels of FOXN3 and NEAT1 strongly correlated with higher histological grades and poor prognosis. Our experiments uncovered that NEAT1 is a facultative component of the SIN3A complex, shedding light on the mechanistic actions of NEAT1 and the SIN3A complex. Further, our study identified the ERalpha-NEAT1-FOXN3/NEAT1/SIN3A-GATA3 axis that is implicated in breast cancer metastasis, providing a mechanistic insight into the pathophysiological function of FOXN3.

The aim of this study was to investigate the role of NEAT1 in hepatocellular carcinoma (HCC), and probe whether NEAT1 participate in the epithelial-mesenchymal transition (EMT) and metastasis regulated by HIF-2alpha. expression of lncRNA NEAT1 was initially assessed in HCC tissues and in a series of HCC cell lines. The correlations between NEAT1 levels and HIF-2alpha were analyzed through plasmid vector construction. The potential underlying mechanisms of NEAT1 in HCC were performed through in vitro and in vivo functional assays. expression of NEAT1, HIF-2alpha were significantly increased in HCC tissues and cell lines. Then, in vitro assays revealed that NEAT1 promotes EMT and metastasis by stimulating the inactivation of HIF-2alpha in HCC. An in vivo animal model also demonstrated the cancer promotion mechanism of NEAT1. In this study, we found that the NEAT1 was high expression in HCC. NEAT1 promotes tumor cell EMT, migration and invasion capacities by stimulating the activation of HIF-2alpha in HCC.CI - (c) 2017 Wiley Periodicals, Inc.