title: High-mobility group box 1 expression and lymph node metastasis in intrahepatic cholangiocarcinoma.
abstract: OBJECTIVE
  To evaluate the prognostic value of high-mobility group box 1 (HMGB1) expression in intrahepatic cholangiocarcinoma (IHCC) and the possible underlying mechanism.
  
  
  METHODS
  Tissue microarray was constructed from 65 IHCC patients. Immunohistochemistry was performed to validate expression of HMGB1 and Vascular endothelial growth factor C (VEGF-C). Real-time PCR and Western blot analyses were used to study transcript and protein levels. The interaction between HMGB1 and VEGF-C was evaluated by siRNA, real-time PCR, and enzyme-linked immuno assays. The correlation between HMGB1 expression and other clinicopathologic parameters was analyzed by χ (2) test, and the univariate as well as multivariate analyses were accomplished by Kaplan-Meier method and Cox-regression model, respectively.
  
  
  RESULTS
  Overall, overexpression of HMGB1 was found in 38/65 (58.8%) IHCCs, whereas VEGF-C overexpression was present in 30/65 (46.2%) cases. Overexpression of HMGB1 was significantly correlated with lymphatic microvessel density (P = 0.031, r = 0.268) and VEGF-C expression (P = 0.041, r = 0.254). With univariate analysis, both HMGB1 (P = 0.001) and VEGF-C (P = 0.004) were identified to be significantly associated with overall survival rate. Multivariate analysis indicated that HMGB1 could be served as an unfavorable independent prognostic factor in IHCCs (P = 0.005). siRNA knockdown of HMGB1 inhibited transforming growth factor-β-induced epithelial-mesenchymal transition (EMT) by elevating E-Cadherin expression and reducing expression of N-Cadherin, Vimentin and Snail in RBE cells. Further in vitro study revealed that HMGB1 silencing significantly decreased the level of VEGF-C, whereas the recombinant HMGB1 increased the VEGF-C level in RBE cells (both P < 0.05), which suggested that HMGB1 could promote lymphatic microvessel density, and subsequently lymphatic invasion, via promoting VEGF-C expression.
  
  
  CONCLUSIONS
  Our results define an important role of HMGB1 in the progression of cholangiocarcinoma, and HMGB1 may serve as a prognostic marker for IHCC patients.
authors: Yun-Fei Xu, Department of Hepatobilliary Surgery, Shandong University Qilu Hospital, Jinan 250012, Shandong Province, China.
authors: Yun-Fei
authors: YF
authors: Xu
authors: Yun-Fei Xu, Department of Hepatobilliary Surgery, Shandong University Qilu Hospital, Jinan 250012, Shandong Province, China.
authors: Fu-Jun
authors: FJ
authors: Ge
authors: Yun-Fei Xu, Department of Hepatobilliary Surgery, Shandong University Qilu Hospital, Jinan 250012, Shandong Province, China.
authors: Bo
authors: B
authors: Han
authors: Yun-Fei Xu, Department of Hepatobilliary Surgery, Shandong University Qilu Hospital, Jinan 250012, Shandong Province, China.
authors: Xiao-Qing
authors: XQ
authors: Yang
authors: Yun-Fei Xu, Department of Hepatobilliary Surgery, Shandong University Qilu Hospital, Jinan 250012, Shandong Province, China.
authors: Hong
authors: H
authors: Su
authors: Yun-Fei Xu, Department of Hepatobilliary Surgery, Shandong University Qilu Hospital, Jinan 250012, Shandong Province, China.
authors: An-Cheng
authors: AC
authors: Zhao
authors: Yun-Fei Xu, Department of Hepatobilliary Surgery, Shandong University Qilu Hospital, Jinan 250012, Shandong Province, China.
authors: Ming-Hong
authors: MH
authors: Zhao
authors: Yun-Fei Xu, Department of Hepatobilliary Surgery, Shandong University Qilu Hospital, Jinan 250012, Shandong Province, China.
authors: Yu-Bao
authors: YB
authors: Yang
authors: Yun-Fei Xu, Department of Hepatobilliary Surgery, Shandong University Qilu Hospital, Jinan 250012, Shandong Province, China.
authors: Jie
authors: J
authors: Yang
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001650:Bile Duct Neoplasms / Q000235:genetics / Q000378:metabolism* / Q000401:mortality / Q000473:pathology*; D001653:Bile Ducts, Intrahepatic / Q000378:metabolism* / Q000473:pathology*; D014408:Biomarkers, Tumor / Q000235:genetics / Q000378:metabolism*; D045744:Cell Line, Tumor; D016009:Chi-Square Distribution; D018281:Cholangiocarcinoma / Q000235:genetics / Q000378:metabolism* / Q000401:mortality / Q000556:secondary*; D058750:Epithelial-Mesenchymal Transition; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D024243:HMGB1 Protein / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D053208:Kaplan-Meier Estimate; D042583:Lymphangiogenesis; D008207:Lymphatic Metastasis; D042601:Lymphatic Vessels / Q000378:metabolism / Q000473:pathology; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D011379:Prognosis; D016016:Proportional Hazards Models; D034622:RNA Interference; D012333:RNA, Messenger / Q000378:metabolism; D012307:Risk Factors; D013997:Time Factors; D014162:Transfection; D042582:Vascular Endothelial Growth Factor C / Q000378:metabolism
chemical_list: D014408:Biomarkers, Tumor; D024243:HMGB1 Protein; C585491:HMGB1 protein, human; D012333:RNA, Messenger; C467486:VEGFC protein, human; D042582:Vascular Endothelial Growth Factor C
keywords: Epithelial-mesenchymal transition; High-mobility group box 1; Intrahepatic cholangiocarcinoma; Lymphatic microvessel density; Vascular endothelial growth factor C