title: FoxM1 overexpression promotes epithelial-mesenchymal transition and metastasis of hepatocellular carcinoma.
abstract: OBJECTIVE
  To investigate the expression of forkhead box protein M1 (FoxM1) in the process of epithelial mesenchymal transition in hepatocellular carcinoma (HCC) and its role in metastasis.
  
  
  METHODS
  FoxM1 and E-cadherin expression in HCC tissue microarray specimens was evaluated by immunohistochemical staining, and statistical methods were applied to analyze the correlation between FoxM1 and epithelial-mesenchymal transition (EMT). Kaplan-Meier analysis of the correlation between the FoxM1 expression level and recurrence or overall survival of HCC patients was performed. The expression of FoxM1, E-cadherin and snail homologue 1 (SNAI1) in HCC cell lines was evaluated by real-time reverse transcription-polymerase chain reaction and Western blot. Hepatocyte growth factor (HGF) was used to induce EMT and stimulate cell migration in HCC cells. The expression of FoxM1 and SNAI1 was regulated by transfection with plasmids pcDNA3.1 and siRNAs in vitro. The occurrence of EMT was evaluated by Transwell assay, morphologic analysis and detection of the expression of EMT markers (E-cadherin and vimentin). Luciferase and chromatin immunoprecipitation assays were used to evaluate whether SNAI1 is a direct transcriptional target of FoxM1.
  
  
  RESULTS
  FoxM1 expression was increased significantly in HCC compared with para-carcinoma (10.7 ± 0.9 vs 8.2 ± 0.7, P < 0.05) and normal hepatic (10.7 ± 0.9 vs 2.7 ± 0.4, P < 0.05) tissues. Overexpression of FoxM1 was correlated with HCC tumor size, tumor number, macrovascular invasion and higher TNM stage, but was negatively correlated with E-cadherin expression in microarray specimens and in cell lines. FoxM1 overexpression was correlated significantly with HCC metastasis and EMT. In vitro, we found that FoxM1 plays a key role in HGF-induced EMT, and overexpression of FoxM1 could suppress E-cadherin expression and induce EMT changes, which were associated with increased HCC cell invasiveness. Next, we confirmed that FOXM1 directly binds to and activates the SNAI1 promoter, and we identified SNAI1 as a direct transcriptional target of FOXM1. Moreover, inhibiting the expression of SNAI1 significantly inhibited FoxM1-mediated EMT.
  
  
  CONCLUSIONS
  FoxM1 overexpression promotes EMT and metastasis of HCC, and SNAI1 plays a critical role in FoxM1-mediated EMT.
authors.affiliation: Fan-Di Meng, Ji-Chao Wei, Kai Qu, Zhi-Xin Wang, Ming-Hui Tai, Hao-Chen Liu, Rui-Yao Zhang, Chang Liu, Department of Hepatobiliary Surgery, the First Affiliated Hospital, School of Medicine, Xi'an Jiaotong University, Xi'an 710061, Shaanxi Province, China.
authors.forename: Fan-Di
authors.initials: FD
authors.lastname: Meng
authors.affiliation: Fan-Di Meng, Ji-Chao Wei, Kai Qu, Zhi-Xin Wang, Ming-Hui Tai, Hao-Chen Liu, Rui-Yao Zhang, Chang Liu, Department of Hepatobiliary Surgery, the First Affiliated Hospital, School of Medicine, Xi'an Jiaotong University, Xi'an 710061, Shaanxi Province, China.
authors.forename: Ji-Chao
authors.initials: JC
authors.lastname: Wei
authors.affiliation: Fan-Di Meng, Ji-Chao Wei, Kai Qu, Zhi-Xin Wang, Ming-Hui Tai, Hao-Chen Liu, Rui-Yao Zhang, Chang Liu, Department of Hepatobiliary Surgery, the First Affiliated Hospital, School of Medicine, Xi'an Jiaotong University, Xi'an 710061, Shaanxi Province, China.
authors.forename: Kai
authors.initials: K
authors.lastname: Qu
authors.affiliation: Fan-Di Meng, Ji-Chao Wei, Kai Qu, Zhi-Xin Wang, Ming-Hui Tai, Hao-Chen Liu, Rui-Yao Zhang, Chang Liu, Department of Hepatobiliary Surgery, the First Affiliated Hospital, School of Medicine, Xi'an Jiaotong University, Xi'an 710061, Shaanxi Province, China.
authors.forename: Zhi-Xin
authors.initials: ZX
authors.lastname: Wang
authors.affiliation: Fan-Di Meng, Ji-Chao Wei, Kai Qu, Zhi-Xin Wang, Ming-Hui Tai, Hao-Chen Liu, Rui-Yao Zhang, Chang Liu, Department of Hepatobiliary Surgery, the First Affiliated Hospital, School of Medicine, Xi'an Jiaotong University, Xi'an 710061, Shaanxi Province, China.
authors.forename: Qi-Fei
authors.initials: QF
authors.lastname: Wu
authors.affiliation: Fan-Di Meng, Ji-Chao Wei, Kai Qu, Zhi-Xin Wang, Ming-Hui Tai, Hao-Chen Liu, Rui-Yao Zhang, Chang Liu, Department of Hepatobiliary Surgery, the First Affiliated Hospital, School of Medicine, Xi'an Jiaotong University, Xi'an 710061, Shaanxi Province, China.
authors.forename: Ming-Hui
authors.initials: MH
authors.lastname: Tai
authors.affiliation: Fan-Di Meng, Ji-Chao Wei, Kai Qu, Zhi-Xin Wang, Ming-Hui Tai, Hao-Chen Liu, Rui-Yao Zhang, Chang Liu, Department of Hepatobiliary Surgery, the First Affiliated Hospital, School of Medicine, Xi'an Jiaotong University, Xi'an 710061, Shaanxi Province, China.
authors.forename: Hao-Chen
authors.initials: HC
authors.lastname: Liu
authors.affiliation: Fan-Di Meng, Ji-Chao Wei, Kai Qu, Zhi-Xin Wang, Ming-Hui Tai, Hao-Chen Liu, Rui-Yao Zhang, Chang Liu, Department of Hepatobiliary Surgery, the First Affiliated Hospital, School of Medicine, Xi'an Jiaotong University, Xi'an 710061, Shaanxi Province, China.
authors.forename: Rui-Yao
authors.initials: RY
authors.lastname: Zhang
authors.affiliation: Fan-Di Meng, Ji-Chao Wei, Kai Qu, Zhi-Xin Wang, Ming-Hui Tai, Hao-Chen Liu, Rui-Yao Zhang, Chang Liu, Department of Hepatobiliary Surgery, the First Affiliated Hospital, School of Medicine, Xi'an Jiaotong University, Xi'an 710061, Shaanxi Province, China.
authors.forename: Chang
authors.initials: C
authors.lastname: Liu
mesh_terms: D015703:Antigens, CD; D015820:Cadherins / Q000235:genetics / Q000378:metabolism; D006528:Carcinoma, Hepatocellular / Q000235:genetics / Q000378:metabolism* / Q000401:mortality / Q000556:secondary / Q000601:surgery; D016022:Case-Control Studies; D002465:Cell Movement; D058750:Epithelial-Mesenchymal Transition; D005260:Female; D000072278:Forkhead Box Protein M1; D051858:Forkhead Transcription Factors / Q000235:genetics / Q000378:metabolism*; D015972:Gene Expression Regulation, Neoplastic; D056945:Hep G2 Cells; D006498:Hepatectomy; D006801:Humans; D053208:Kaplan-Meier Estimate; D008113:Liver Neoplasms / Q000235:genetics / Q000378:metabolism* / Q000401:mortality / Q000473:pathology / Q000601:surgery; D008297:Male; D008875:Middle Aged; D009361:Neoplasm Invasiveness; D009364:Neoplasm Recurrence, Local; D009367:Neoplasm Staging; D034622:RNA Interference; D015398:Signal Transduction; D000071250:Snail Family Transcription Factors; D013997:Time Factors; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism; D014158:Transcription, Genetic; D014162:Transfection; D016896:Treatment Outcome; D015854:Up-Regulation
chemical_list: D015703:Antigens, CD; C513384:CDH1 protein, human; D015820:Cadherins; C107585:FOXM1 protein, human; D000072278:Forkhead Box Protein M1; D051858:Forkhead Transcription Factors; C000604407:SNAI1 protein, human; D000071250:Snail Family Transcription Factors; D014157:Transcription Factors
keywords: E-cadherin; Epithelial-mesenchymal transition; Forkhead box protein M1; Hepatocellular carcinoma; Snail homolog 1