High-mobility group box 1 expression and lymph node metastasis in intrahepatic cholangiocarcinoma

AIM: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).Realtime PCR and Western blot analyses were used to study transcript and protein levels.The interaction between HMGB1 and VEGF-C was evaluated by si RNA,real-time PCR,and enzyme-linked immuno assays.The correlation between HMGB1 expression and other clinicopathologic parameters was analyzed byχ2 test,and the univariate as well as multivariate analyses were accomplished by Kaplan-Meier method and Coxregression 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.Multivariateanalysis indicated that HMGB1 could be served as an unfavorable independent prognostic factor in IHCCs(P=0.005).si RNA knockdown of HMGB1 inhibited transforming growth factor-β-induced epithelialmesenchymal 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 HMGB1increased 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.CONCLUSION:Our results define an important role of HMGB1 in the progression of cholangiocarcinoma,and HMGB1 may serve as a prognostic marker for IHCC patients.

Recombinant adenovirus with human indoleamine-2,3- dioxygenase and hepatitis B virus preS was constructed and expressed in HepG2 cells

Background Indoleamine-2,3-dioxygenase （IDO） is proven to suppress hepatitis B virus （HBV） specific immune response and depletion of IDO may be a useful approach for HBV therapy. To test this concept, we constructed recombinant adenovirus with human IDO and HBV preS, which would form the basis for future in vivo experiments.Methods The fragment of human IDO and HBV preS cDNA were subcloned into multiple cloning sites in an adenoviral vector system containing two cytomegalovirus （CMV） promoters. Recombination was conducted in the Escherichia coli BJ5183. The recombinant adenovirus containing hlDO gene and HBVpreS gene was packaged and amplified in 293 cells.Integration was confirmed by polymerase chain reaction as well as the quantification of viral titers. HepG2 cells were infected with the recombinant adenovirus and mRNA and protein specific for hlDO and HBVpreS was detected by RT-PCR and Western blotting respectively.Results The recombinant adenovirus was produced successfully. Its titer was 2.5x109 efu/ml. IDO and HBVpreS mRNA as well as the encoded proteins could be found in transfected HepG2 cells, but not in control HepG2 cells.Conclusion The transfer of hlDO-HBVpreS with double-promoter adenoviral vector was efficient. The recombinant adenovirus with hlDO and HBVpreS would provide the experimental basis for future studies.