Background: Hepatocellular carcinoma (HCC) is a typical malignancy in a background of chronic inflammation. Th17 cells (a major source of IL-17) constitute crucial components of infiltrating inflammatory/immune cells in HCC and can amplify inflammatory response via binding to interleukin-17 receptor (IL-17R). Thus, we investigated the expression and clinical significance of IL-17 and IL-17 receptor family cytokines in HCC. Methods: The expression and prognostic value of IL-17 and IL-17R (A-E) were examined in 300 HCC patients after resection. Six Th17 associated cytokines in serum (n = 111) were quantified using enzyme-linked immunosorbent assays. Phenotypic features of IL-17⁺ CD4⁺ T cells were determined by flow cytometry analysis. Results: High expression of intratumoral IL-17 and IL1-7RE were significantly associated with poorer survival (p = 0.016 and <0.001, respectively) and increased recurrence (both P < 0.001) of HCC patients. Moreover, intratumoral IL-17, individually or synergistically with IL-17RE, could predict HCC early recurrence and late recurrence. Also, peritumoral IL-17RE showed the prognostic ability in HCC (P < 0.001 for OS/TTR). Furthermore, expression levels of Th17 associated cytokines including IL-6, -22, -17R and TNF-α were increased in serum of HCC patients compared to haemangioma patients. Importantly, activated human hepatic stellate cells induced in vitro expansion of IL-17⁺ CD4⁺ T cells. Conclusions: High expression of IL-17 and IL-17RE were promising predictors for poor outcome of HCC patients. The protumor power of IL-17 producing CD4⁺ T cells was probably involved in the crosstalk with different types of inflammatory/immune cells in HCC.

Hepatocellular carcinoma (HCC) is a typical inflammation‐related malignancy characterized by high postoperative recurrence and metastasis. Although several inflammatory cells and inflammatory signatures have been linked to poor prognosis, the inflammation‐associated molecular mechanisms of HCC development and progression are largely unknown. Here we show that triggering receptor expressed in myeloid cells (TREM)‐1, a transmembrane receptor expressing in myeloid cells, was also expressed in tumor‐activated hepatic stellate cells (HSCs) and associated with the aggressive behavior of HCC cells. Enzyme‐linked immunosorbent assay was used to measure the expression levels of soluble TREM‐1 (sTREM‐1) in activated hepatic stellate cells supernatant and 92 preoperative and postoperative plasmas of patients with malignancy and/or benign liver tumor/disease, respectively. Expression levels of TREM‐1 were assessed by immunohistochemistry in tissue microarray from 240 patients with HCC. As a result, increased secretion of sTREM‐1 from activated HSCs was observed after co‐culture with HCC cell lines (P < 0.001), and conditioned medium collected from activated HSCs/cancer associated myofibroblasts (CAMFs) with or without agonist/inhibitor of TREM‐1 significantly changed the migratory ability of HCC cells. The levels of sTREM‐1 were significantly higher in patients with HCC than those with benign liver tumors (P < 0.005). Peritumoral density of TREM‐1 was shown to be an independent prognosis predictor according to univariate (P < 0.001 for both overall survival and time to recurrence) and multivariate analysis (P = 0.008 for overall survival; P = 0.005 for time to recurrence). Thus, these observations suggest that TREM‐1 is related to the aggressive tumor behavior and has potential value as a prognostic factor for HCC. (Cancer Sci 2012; 103: 984–992)

Monoacylglycerol lipase (MAGL) is a key enzyme in lipid metabolism that is demonstrated to be involved in tumor progression through both energy supply of fatty acid (FA) oxidation and enhancing cancer cell malignance. The aim of this study was to investigate whether MAGL could be a potential therapeutic target and prognostic indicator for hepatocellular carcinoma (HCC). To evaluate the relationship between MAGL levels and clinical characteristics, a tissue microarray (TMA) of 353 human HCC samples was performed. MAGL levels in HCC samples were closely linked to the degree of malignancy and patient prognosis. RNA interference, specific pharmacological inhibitor JZL-184 and gene knock-in of MAGL were utilized to investigate the effects of MAGL on HCC cell proliferation, apoptosis, and invasion. MAGL played important roles in both proliferation and invasion of HCC cells through mechanisms that involved prostaglandin E2 (PGE2) and lysophosphatidic acid (LPA). JZL-184 administration significantly inhibited tumor growth in mice. Furthermore, we confirmed that promoter methylation of large tumor suppressor kinase 1 (LATS1) resulted in dysfunction of the Hippo signal pathway, which induced overexpression of MAGL in HCC. These results indicate that MAGL could be a potentially novel therapeutic target and prognostic indicator for HCC.

The complexity of liver tumorigenesis is underscored by the recently observed anti-oncogenic effects of oncoproteins, although the mechanisms are unclear. Shp2/Ptpn11 is a proto-oncogene in hematopoietic cells and antagonizes the effect of tumor suppressor Pten in leukemogenesis. In contrast, we show here cooperative functions of Shp2 and Pten in suppressing hepatocarcinogenesis. Ablating both Shp2 and Pten in hepatocytes induced early-onset non-alcoholic steatohepatitis (NASH) and promoted genesis of liver tumor-initiating cells likely due to augmented cJun expression/activation and elevated ROS and inflammation in the hepatic microenvironment. Inhibiting cJun partially suppressed NASH-driven liver tumorigenesis without improving NASH. SHP2 and PTEN deficiencies were detected in liver cancer patients with poor prognosis. These data depict a mechanism of hepato-oncogenesis and suggest a potential therapeutic strategy.