title: Long noncoding RNA CCAT1 promotes hepatocellular carcinoma progression by functioning as let-7 sponge.
abstract: BACKGROUND
  Long noncoding RNAs (lncRNAs) have been identified as having functional roles in cancer biology and are deregulated in many cancers. The present study aimed to determine the expression, roles and functional mechanisms of a long noncoding RNA CCAT1 in the progression of hepatocellular carcinoma (HCC).
  
  
  METHODS
  CCAT1 expression levels in 66 pairs of HCC tissues and pair-matched noncancerous hepatic tissues were tested by real-time PCR. The effects of CCAT1 on HCC cells proliferation and migration were assessed using in vitro cell proliferation and migration assays. A computational screen of microRNAs (miRNAs) target sites in CCAT1 was conducted to search for specific miRNAs binding to CCAT1. The specific binding between CCAT1 and miRNAs was confirmed by RNA immunoprecipitation assay combined with luciferase reporter assay.
  
  
  RESULTS
  CCAT1 levels are markedly increased in HCC tissues compared with pair-matched noncancerous hepatic tissues. Up-regulation of CCAT1 is correlated with tumor size, microvascular invasion, AFP and poor prognosis. CCAT1 promotes the proliferation and migration of HCC cells. CCAT1 functions as a molecular sponge for let-7, antagonizes its functions, and leads to the de-repression of its endogenous targets HMGA2 and c-Myc. The effect of CCAT1 on HCC cell proliferation and migration is dependent upon its competitively binding to let-7.
  
  
  CONCLUSIONS
  These data suggest that CCAT1 plays a pivotal role in HCC progression via functioning as let-7 sponge, and implicate the potential application of CCAT1 for the prognosis and treatment of HCC.
authors.affiliation: Department of Hepatobiliary Surgery, The Eastern Hospital of the First Affiliated Hospital, Sun Yat-sen University, Eastern Huangpu Road No. 183, Guangzhou, 510700, China. dengliang201000@126.com.
authors.forename: Liang
authors.initials: L
authors.lastname: Deng
authors.affiliation: Department of Gastrointestinal and Pancreatic Surgery, The Eastern Hospital of the First Affiliated Hospital, Sun Yat-sen University, Eastern Huangpu Road No. 183, Guangzhou, 510700, China. yangshibin1980@163.com.
authors.forename: Shi-Bin
authors.initials: SB
authors.lastname: Yang
authors.affiliation: Department of Hepatobiliary Surgery, The Eastern Hospital of the First Affiliated Hospital, Sun Yat-sen University, Eastern Huangpu Road No. 183, Guangzhou, 510700, China. xufengfeng0313@163.com.
authors.forename: Feng-Feng
authors.initials: FF
authors.lastname: Xu
authors.affiliation: Department of Hepatobiliary Surgery, The Eastern Hospital of the First Affiliated Hospital, Sun Yat-sen University, Eastern Huangpu Road No. 183, Guangzhou, 510700, China. jihongzhangsyu@163.com.
authors.forename: Ji-Hong
authors.initials: JH
authors.lastname: Zhang
mesh_terms: D000328:Adult; D000368:Aged; D001665:Binding Sites; D006528:Carcinoma, Hepatocellular / Q000235:genetics* / Q000401:mortality / Q000473:pathology*; D045744:Cell Line, Tumor; D002465:Cell Movement / Q000235:genetics; D049109:Cell Proliferation; D018450:Disease Progression; D005260:Female; D015870:Gene Expression; D006801:Humans; D008113:Liver Neoplasms / Q000235:genetics* / Q000401:mortality / Q000473:pathology*; D008297:Male; D035683:MicroRNAs / Q000737:chemistry / Q000235:genetics*; D008875:Middle Aged; D009389:Neovascularization, Pathologic; D009690:Nucleic Acid Conformation; D011379:Prognosis; D062085:RNA, Long Noncoding / Q000737:chemistry / Q000235:genetics*; D047368:Tumor Burden
chemical_list: C579842:CCAT1 long noncoding RNA, human; D035683:MicroRNAs; D062085:RNA, Long Noncoding; C487931:mirnlet7 microRNA, human