title: Sox12, a direct target of FoxQ1, promotes hepatocellular carcinoma metastasis through up-regulating Twist1 and FGFBP1.
abstract: Metastasis is the main reason for high recurrence and poor survival of hepatocellular carcinoma (HCC) after curative resection. However, the molecular mechanism underlying HCC metastasis remains unclear. Here, we report on a novel function of SRY (sex determining region Y)-box 12 (Sox12), a member of the SYR-related high mobility group box family proteins, in promoting HCC metastasis. Overexpression of Sox12 was significantly correlated with loss of tumor encapsulation, microvascular invasion, and a higher tumor-nodule-metastasis (TNM) stage and indicated poor prognosis in human HCC patients. Sox12 expression was an independent and significant risk factor for recurrence and reduced survival after curative resection. Overexpression of Sox12 induced epithelial-mesenchymal transition by transactivating Twist1 expression. Down-regulation of Twist1 decreased Sox12-enhanced HCC migration, invasion, and metastasis, whereas up-regulation of Twist1 rescued the decreased migration, invasion, and metastasis induced by Sox12 knockdown. Additionally, serial deletion, site-directed mutagenesis, and chromatin immunoprecipitation assays showed that fibroblast growth factor binding protein 1 (FGFBP1) was a direct transcriptional target of Sox12. Knockdown of FGFBP1 decreased Sox12-mediated HCC invasion and metastasis, whereas overexpression of FGFBP1 rescued the decreased invasion and metastasis induced by Sox12 knockdown. Furthermore, forkhead box Q1 (FoxQ1) directly bound to the Sox12 promoter and transactivated its expression, which contributed to Sox12 overexpression in human HCC. Knockdown of Sox12 dramatically decreased FoxQ1-mediated HCC metastasis. In two independent cohorts of human HCC tissues, Sox12 expression was positively correlated with Twist1, FGFBP1, and FoxQ1 expression, and patients with positive coexpression of Sox12/Twist1, Sox12/FGFBP1, or FoxQ1/Sox12 were associated with poorer prognosis.
  
  
  CONCLUSIONS
  Up-regulated Sox12 induced by FoxQ1 promotes HCC invasion and metastasis by transactivating Twist1 and FGFBP1 expression. Thus, our study implicates Sox12 as a potential prognostic biomarker and a novel therapeutic target for HCC.
authors.affiliation: State Key Laboratory of Cancer Biology and Xijing Hospital of Digestive Diseases, Fourth Military Medical University, Xi'an, People's Republic of China.|Department of Gastroenterology, Tongji Hospital of Tongji Medical College, Huazhong University of Science and Technology, Wuhan, People's Republic of China.
authors.forename: Wenjie
authors.initials: W
authors.lastname: Huang
authors.affiliation: State Key Laboratory of Cancer Biology and Xijing Hospital of Digestive Diseases, Fourth Military Medical University, Xi'an, People's Republic of China.
authors.forename: Zhangqian
authors.initials: Z
authors.lastname: Chen
authors.affiliation: State Key Laboratory of Cancer Biology and Xijing Hospital of Digestive Diseases, Fourth Military Medical University, Xi'an, People's Republic of China.
authors.forename: Xin
authors.initials: X
authors.lastname: Shang
authors.affiliation: Department of Gastroenterology, Tongji Hospital of Tongji Medical College, Huazhong University of Science and Technology, Wuhan, People's Republic of China.
authors.forename: Dean
authors.initials: D
authors.lastname: Tian
authors.affiliation: Department of Gastroenterology, Tongji Hospital of Tongji Medical College, Huazhong University of Science and Technology, Wuhan, People's Republic of China.
authors.forename: Daowen
authors.initials: D
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Cancer Biology and Xijing Hospital of Digestive Diseases, Fourth Military Medical University, Xi'an, People's Republic of China.
authors.forename: Kaichun
authors.initials: K
authors.lastname: Wu
authors.affiliation: State Key Laboratory of Cancer Biology and Xijing Hospital of Digestive Diseases, Fourth Military Medical University, Xi'an, People's Republic of China.
authors.forename: Daiming
authors.initials: D
authors.lastname: Fan
authors.affiliation: State Key Laboratory of Cancer Biology and Xijing Hospital of Digestive Diseases, Fourth Military Medical University, Xi'an, People's Republic of China.|Department of Gastroenterology, Tongji Hospital of Tongji Medical College, Huazhong University of Science and Technology, Wuhan, People's Republic of China.
authors.forename: Limin
authors.initials: L
authors.lastname: Xia
mesh_terms: D000328:Adult; D006528:Carcinoma, Hepatocellular / Q000378:metabolism*; D002352:Carrier Proteins / Q000378:metabolism*; D058750:Epithelial-Mesenchymal Transition; D005260:Female; D051858:Forkhead Transcription Factors / Q000378:metabolism; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D036341:Intercellular Signaling Peptides and Proteins / Q000378:metabolism*; D008113:Liver Neoplasms / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D009362:Neoplasm Metastasis; D009687:Nuclear Proteins / Q000378:metabolism*; D055751:SOXC Transcription Factors / Q000378:metabolism*; D051879:Twist-Related Protein 1 / Q000378:metabolism*
chemical_list: D002352:Carrier Proteins; C484579:FOXQ1 protein, human; D051858:Forkhead Transcription Factors; D036341:Intercellular Signaling Peptides and Proteins; D009687:Nuclear Proteins; C107423:SOX12 protein, human; D055751:SOXC Transcription Factors; C103173:TWIST1 protein, human; D051879:Twist-Related Protein 1; C070699:FGFBP1 protein, human