title: The Effect of MicroRNA-375 Overexpression, an Inhibitor ofHelicobacter pylori-Induced Carcinogenesis, on lncRNA SOX2OT.
abstract: BACKGROUND
  Helicobacter pyloriis a major human pathogenic bacterium in gastric mucosa. Although the association between gastric cancer andH. pylorihas been well-established, the molecular mechanisms underlyingH. pylori-induced carcinogenesis are still under investigation. MicroRNAs (miRNAs) are small noncoding RNAs that modulate gene expression at the posttranscriptional level. Recently, studies have revealed that miRNAs are involved in immune response and host cell response to bacteria. Also, microRNA-375 (miR-375) is a key regulator of epithelial properties that are necessary for securing epithelium-immune system cross-talk. It has been recently reported that miR-375 acts as an inhibitor ofH. pylori-induced gastric carcinogenesis. There are few reports on miRNA-mediated targeting long noncoding RNAs (lncRNAs).
  
  
  OBJECTIVE
  This study aimed to examine the possible effect of miR-375 as an inhibitor ofH. pylori-induced carcinogenesis on the expression of lncRNA SOX2 overlapping transcript (SOX2OT) and SOX2, a master regulator of pluripotency of cancer stem cells.
  
  
  METHODS
  In a model cell line, NT-2 was transfected with the constructed expression vector pEGFP-C1 contained miR-375. The RNA isolations and cDNA synthesis were performed after 48 hours of transformation. Expression of miR-375 and SOX2OT and SOX2 were quantified using real-time polymerase chain reaction and compared with control cells transfected with pEGFP-C1-Mock clone. Cell cycle modification was also compared after transfections using the flow cytometry analysis.
  
  
  RESULTS
  Following ectopic expression of miR-375, SOX2OT and SOX2 expression analysis revealed a significant decrease in their expression level (P < 0.05) in NT-2 cells compared to the control. Cell cycle analysis following ectopic expression of miR-375 in the NT-2 cells using propidium iodine staining revealed significant extension in sub-G1 cell cycle.
  
  
  CONCLUSIONS
  This is the first report to show down-regulation of SOX2OT and SOX2 following induced expression of miR-375. This finding may suggest expression regulation potential between different classes of ncRNAs, for example between miR-375 and SOX2OT. This data not only extends our understanding of possible ncRNA interactions in cancers but also may open novel investigation lines towards elucidation of molecular mechanisms controllingH. pyloriinflammation and carcinogenesis.
authors: National Institute of Genetic Engineering and Biotechnology, Tehran, IR Iran; Golestan Research Center of Gastroenterology and Hepatology, Golestan University of Medical Sciences, Gorgan, IR Iran.
authors: Mohammad
authors: M
authors: Shafiee
authors: National Institute of Genetic Engineering and Biotechnology, Tehran, IR Iran.
authors: Seyed Ahmad
authors: SA
authors: Aleyasin
authors: Department of Molecular Genetics, Faculty of Biological Sciences, Tarbiat Modares University, Tehran, IR Iran.
authors: Seyed Javad
authors: SJ
authors: Mowla
authors: Department of Pathology, Shariati Hospital, School of Medicine, Tehran University of Medical Sciences, Tehran, IR Iran.
authors: Mohammad
authors: M
authors: Vasei
authors: Department of Medical Parasitology and Mycology, School of Allied Medicine, Iran University of Medical Sciences, Tehran, IR Iran.
authors: Seyed Amir
authors: SA
authors: Yazdanparast
keywords: Helicobacter pylori; Long Noncoding; MicroRNAs; RNA; miR-375