Background/Aims: TGF-β plays a key role in the progression of various tumors. The main objective of our study was to investigate whether TGF-β is able to regulate N-nitrosodiethylamine (DEN)-induced hepatocellular carcinoma (HCC) progression in a mouse model by inducing Treg cell polarization. Methods: HCC progression, TGF-β and Foxp3 expression levels, serum TGF-β, IL10 and GP73 levels as well as percentage of Treg cells were analyzed in healthy, HCC and HCC+SM-16 mouse groups. The effect of TGF-β on Treg cell polarization in vitro was measured by flow cytometric analysis. The expression of TGF-β and IL10 was identified by IHC in HCC patients and the correlation between TGF-β and IL10 was also assessed. Results: TGF-β expression is up-regulated in a DEN-induced HCC mouse model. TGF-β can promote the differentiation of Foxp3⁺CD4⁺ T cells (Treg cells) in vitro. However, blocking the TGF-β pathway with a specific TGF-β receptor inhibitor, SM-16, reduced HCC progression and the percentage of Treg cells in liver tissue. The correlation between TGF-β and Treg cells was also confirmed in HCC patients and the expression of both TGF-β and IL-10 was shown to be associated with HCC progression. Conclusion: TGF-β is necessary for HCC progression, acting by inducing Treg cell polarization.

Background/Aims: MicroRNAs (miRNAs) play critical roles during carcinogenesis and cancer progression. Down-regulation of miR-204 has been frequently observed in various cancers. In this study, we investigated the roles and mechanisms of miR-204 in human intrahepatic cholangiocarcinoma (ICC). Methods: The relative expression of miR-204 in ICC tissues and cell lines was monitored by qRT-PCR. Effects of miR-204 were studied in human ICC cell lines HuH28 and HuCCT1, and cells were analyzed for proliferation, migration and invasion. Expression levels of miR-204 target gene Slug and EMT markers (E-cadherin and vimentin) in ICC cell lines and tissues were measured by qRT-PCR, western blotting and immunofluorescence. Results: miR-204 was frequently downregulated in human ICC, and the low-level expression of miR-204 was significantly associated with lymph node metastasis. Overexpression of miR-204 dramatically suppressed ICC cell migration and invasion, as well as the epithelial-mesenchymal transition process (EMT). Slug was identified as a direct target of miR-204, and its downregulation by miR-204 in HuH28 cells reversed EMT, as shown by the increased expression of the epithelial marker E-cadherin and decreased expression of the mesenchymal marker vimentin. Conclusion: These findings suggest that miR-204 plays negative roles in the invasive and/or metastatic potential of ICC, and that its suppressive effects are mediated by repressing Slug expression.

miR-182 is an important mediator of GBC metastasis, thus offering a new target for the development of therapeutic agents against GBC.

Hepatocellular carcinoma (HCC) is one of the most common cancers worldwide. Systemic chemotherapy plays an important role in the treatment of patients with advanced liver cancer. However, chemoresistance to cisplatin is a major limitation of cisplatin-based chemotherapy in the clinic, and the underlying mechanism of such resistance is not fully understood. In this study, we found that nuclear accumulation of β-catenin was higher in cisplatin-resistant Huh7 cells than in Huh7 cells, indicating that Wnt signaling was activated in cisplatin-resistant cells. Wnt signaling inhibition increased cisplatin-induced growth inhibition in hepatoma cell. We further demonstrated that sorafenib could inhibit Wnt signaling in Huh7 cells and cisplatin-resistant Huh7 cells. Co-treatment with cisplatin and sorafenib was more effective in inhibiting cancer cell proliferation than cisplatin alone in vitro and in vivo, whereas Wnt3a (Wnt activator) treatment abrogated sorafenib-induced growth inhibition. These data demonstrated that sorafenib sensitizes human HCC cell to cisplatin via suppression of Wnt/β-catenin signaling, thus offering a new target for chemotherapy of HCC.

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Krüppel-like factor 8 (KLF8) is highly expressed in hepatocellular carcinoma (HCC) and contributes to tumor initiation and progression by promoting HCC cell proliferation and invasion. However, the role of KLF8 in liver cancer stem cells (LCSCs) is not known. In the current study, we investigated the role of KLF8 in LCSCs to determine if KLF8 is a novel marker of these cells. We found that KLF8 was highly expressed in primary HCC tumors, distant migrated tissues, and LCSCs. Patients with high KLF8 expression had a poor prognosis. KLF8 promoted stem cell-like features through activation of the Wnt/β-catenin signaling pathway. Cell apoptosis was significantly increased in HCC cells with knockdown of KLF8 compared with the control cells when treated with the same doses of sorafenib or cisplatin. Taken together, our study shows that KLF8 plays a potent oncogenic role in HCC tumorigenesis by maintaining stem cell-like features through activation of the Wnt/β-catenin signaling pathway and promoting chemoresistance. Thus, targeting KLF8 may provide an effective therapeutic approach to suppress tumorigenicity of HCC. © 2016 Wiley Periodicals, Inc.

T-cell immunoreceptor with Ig and ITIM domains (TIGIT) is a checkpoint receptor that mediates both T-cell and natural killer (NK)–cell exhaustion in tumors. An Fc-TIGIT fusion protein was shown to induce an immune-tolerance effect in a previous report, but the relevance of the TIGIT-Fc protein to tumor immunity is unknown. Here, we found that TIGIT-Fc promotes, rather than suppresses, tumor immunity. TIGIT-Fc treatment promoted the effector function of CD8+ T and NK cells in several tumor-bearing mouse models. TIGIT-Fc treatment resulted in potent T cell– and NK cell–mediated tumor reactivity, sustained memory-induced immunity in tumor rechallenge models, enhanced therapeutic effects via an antibody against PD-L1, and induction of Th1 development in CD4+ T cells. TIGIT-Fc showed a potent antibody-dependent cell-mediated cytotoxicity effect but had no intrinsic effect on tumor cell development. Our findings elucidate the role of TIGIT-Fc in tumor immune reprogramming, suggesting that TIGIT-Fc treatment alone or in combination with other checkpoint receptor blockers is a promising anticancer therapeutic strategy.

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