title: Downregulation of miR-138 sustains NF-κB activation and promotes lipid raft formation in esophageal squamous cell carcinoma.
abstract: OBJECTIVE
  Constitutive activation of NF-κB signaling plays vital roles in esophageal squamous cell carcinoma (ESCC) progression. The aim of this study was to evaluate the effect of miR-138 on NF-κB activation and ESCC progression.
  
  
  METHODS
  Expression of miR-138 in ESCC cell lines, ESCC tissues, and 205 archived ESSC specimens was determined using real-time PCR analysis. Anchorage-independent growth, chicken chorioallantoic membrane, Transwell matrix invasion and Annexin V-binding assays, and a xenograft tumor model were used to determine the role of miR-138 in ESCC progression. The effect of miR-138 on NF-κB activation was investigated using IKK in vitro kinase, electrophoretic mobility shift, lipid raft isolation, and luciferase reporter assays.
  
  
  RESULTS
  miR-138 was downregulated and inversely correlated with tumor progression and patient survival in ESCCs. Downregulation of miR-138 enhanced, whereas upregulation of miR-138 reduced, the aggressive phenotype of ESCC cells both in vitro and in vivo. Silencing miR-138 promoted K63-linked polyubiquitination of the NF-κB signaling intermediaries TRAF2 and RIP1 and sustained NF-κB activation. Furthermore, downregulation of miR-138 induced lipid raft formation via upregulating multiple components of lipid rafts, including FLOT1, FLOT2, and caveolin-1. Importantly, the in vitro analysis was consistent with a significant inverse correlation between miR-138 expression and NF-κB hyperactivation in a cohort of human ESCC specimens.
  
  
  CONCLUSIONS
  Our results show that miR-138 functions as a tumor-suppressive miRNA and that downregulation of miR-138 contributes to constitutive NF-κB activation and ESCC progression.
authors: State Key Laboratory of Oncology in Southern China, Department of Experimental Research, Cancer Center, Sun Yat-sen University, Guangzhou, Guangdong, China.
authors: Hui
authors: H
authors: Gong
authors: Libing
authors: L
authors: Song
authors: Chuyong
authors: C
authors: Lin
authors: Aibin
authors: A
authors: Liu
authors: Xi
authors: X
authors: Lin
authors: Jueheng
authors: J
authors: Wu
authors: Mengfeng
authors: M
authors: Li
authors: Jun
authors: J
authors: Li
mesh_terms: D020413:3' Untranslated Regions / Q000235:genetics; D000818:Animals; D014408:Biomarkers, Tumor / Q000235:genetics / Q000378:metabolism; D015153:Blotting, Western; D002294:Carcinoma, Squamous Cell / Q000235:genetics / Q000401:mortality / Q000473:pathology*; D051242:Caveolin 1 / Q000235:genetics / Q000378:metabolism; D002645:Chickens; D049033:Chorioallantoic Membrane / Q000378:metabolism / Q000473:pathology; D017931:DNA Primers / Q000737:chemistry; D024202:Electrophoretic Mobility Shift Assay; D004938:Esophageal Neoplasms / Q000235:genetics / Q000401:mortality / Q000473:pathology*; D004947:Esophagus / Q000378:metabolism / Q000473:pathology*; D020869:Gene Expression Profiling; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D007124:Immunoenzyme Techniques; D008156:Luciferases / Q000378:metabolism; D021962:Membrane Microdomains / Q000378:metabolism / Q000473:pathology*; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism; D051379:Mice; D008807:Mice, Inbred BALB C; D008819:Mice, Nude; D035683:MicroRNAs / Q000235:genetics*; D016328:NF-kappa B / Q000235:genetics / Q000378:metabolism*; D020411:Oligonucleotide Array Sequence Analysis; D025821:Polyubiquitin / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics; D060888:Real-Time Polymerase Chain Reaction; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015996:Survival Rate; D023041:Xenograft Model Antitumor Assays
chemical_list: D020413:3' Untranslated Regions; D014408:Biomarkers, Tumor; D051242:Caveolin 1; D017931:DNA Primers; C546110:MIRN138 microRNA, human; D008565:Membrane Proteins; D035683:MicroRNAs; D016328:NF-kappa B; D012333:RNA, Messenger; C106354:flotillins; D025821:Polyubiquitin; D008156:Luciferases