βII-spectrin (SPTBN1) is an adapter protein for Smad3/Smad4 complex formation during TGF-β signal transduction. Forty percent of SPTBN1+/− mice spontaneously develop hepatocellular carcinoma (HCC), and most cases of human HCC have significant reductions in SPTBN1 expression. In this study, we investigated the possible mechanisms by which loss of SPTBN1 may contribute to tumorigenesis. Livers of SPTBN1+/− mice, compared to wild type mouse livers, display a significant increase in EpCAM+ cells and overall EpCAM expression. Inhibition of SPTBN1 in human HCC cell lines increased the expression of stem cell markers EpCAM, Claudin7 and Oct4, as well as decreased E-cadherin expression and increased expression of vimentin and c-Myc, suggesting reversion of these cells to a less differentiated state. HCC cells with decreased SPTBN1 also demonstrate increased sphere formation, xenograft tumor development and invasion. Here, we investigate possible mechanisms by which SPTBN1 may influence the stem cell traits and aggressive behavior of HCC cell lines. We found that HCC cells with decreased SPTBN1 express much less of the Wnt inhibitor Kallistatin and exhibit decreased β-catenin phosphorylation and increased β-catenin nuclear localization, indicating Wnt signaling activation. Restoration of Kallistatin expression in these cells reversed the observed Wnt activation. Analysis of publicly available expression array datasets indicates that SPTBN1 expression in human HCC tissues is positively correlated with E-cadherin and Kallistatin levels, and decreased SPTBN1 and Kallistatin gene expression is associated with decreased relapse-free survival. Our data suggest that loss of SPTBN1 activates Wnt signaling, which promotes acquisition of stem cell-like features, and ultimately contributes to malignant tumor progression.

The liver is the major metabolic organ and is subjected to constant attacks from chronic viral infection, uptake of therapeutic drugs, life behavior (alcoholic), and environmental contaminants, all of which result in chronic inflammation, fibrosis, and ultimately, cancer. Therefore, there is an urgent need to discover effective therapeutic agents for the prevention and treatment of liver injury; the ideal drug being a naturally occurring biological inhibitor. Here, we establish the role of IL30 as a potent anti-inflammatory cytokine which can inhibit inflammation-induced liver injury. In contrast, IL27, which contains IL30 as a subunit, is not hepatoprotective. Interestingly, IL30 is induced by the pro-inflammatory signal such as IL12 through IFNγ/STAT1 signaling. In animal models, administration of IL30 via a gene therapy approach prevents and treats both IL12-, IFNγ-, and Concanavalin A -induced liver toxicity. Likewise, immunohistochemistry analysis of human tissue samples revealed that IL30 is highly expressed in hepatocytes yet barely expressed in inflammation-induced tissue such as fibrous/connective tissue. These novel observations reveal a novel role of IL30 as a therapeutic cytokine that suppresses pro-inflammatory cytokine-associated liver toxicity.