High malignancy and early metastasis are the hallmarks of hepatocellular carcinoma (HCC). Here, we report that Cezanne2 expression is downregulated in HCC cells and in HCC patients' tumorous tissues and that Cezanne2 is inversely associated with Snail1 expression in HCC patients' tumorous tissues. Chromatin immunoprecipitation assays and the reporter gene assay showed that Snail1 binds to the promoter of the Cezanne2 gene and mediates the direct consequence of Cezanne2 repression. Enhanced expression of Cezanne2 could suppress proliferation, migration and invasion in HCC cells. Further, Cezanne2 could regulate MMP (matrix metalloproteinase)2, MMP9 and ICAM1 (intercellular adhesion molecule) levels through modulation of the NF-κB (nuclear factor kappa-light-chain-enhancer of activated B cell) signaling cascade. Co-immunoprecipitation and in vivo deubiquitination assay indicated that Cezanne2 interacts with TNF receptor-associated factor (TRAF)6 and cleaves the polyubiquitin from TRAF6 substrates. Our data reveal that Snail1-mediated suppression of Cezanne2 may have a key role in HCC malignancy.

The interleukin-12B (IL12B) gene encodes the p40 chain of IL-12, a pro-inflammatory cytokine that antagonizes Th2 phenotype and, hence, may have a critical role in the pathogenesis of allergic asthma. In this report, we describe the identification of a novel IL12B promoter polymorphism (T-to-A exchange) at position À 536. The IL12B À 536AA genotype was significantly associated with asthma in the Chinese populations (P ¼ 0.011, odds ratio ¼ 2.227). The risk-associated A allele was linked to reduced expression of IL12B mRNA levels and IL12B production in asthmatic patients. Luciferase reporter assay provided evidence that risk-associated A allele reduced the promoter activity of IL12B gene compared with those of the promoter containing the protective T allele. We further observed that decreasing binding effects between the risk alleles A of IL12B and CCAAT/enhancer binding protein alpha (C/EBPa) through A allele sequence mediated streptavidin-conjugated agarose pulldown and biotin-labelled A allele mediated electrophoretic mobility shift assay. We also observed additive effects of the risk alleles of IL12B and decreased mRNA levels of C/EBPa in asthmatic patients. Therefore, we postulated that the presence of À 536A allele in IL12B promoter could predispose to the development of allergic asthma.