Inhibition of anti-inflammatory pathway through suppressors of cytokine signalling (Socs2/Socs3) in the initiation of hepatocellular carcinoma

Involvement of aryl hydrocarbon receptor in the aflatoxin B1 and fumonisin B1 effects on in vitro differentiation of murine regulatory-T and Th17 cells

Aflatoxin B1 (AFB1) and fumonisin B1 (FB1) are mycotoxins widely found as cereal contaminants, and their co-consumption is associated with liver cancer. Both are immunotoxic, but their interactions have been little studied. This work was aimed to evaluate in mouse spleen mononuclear cells (SMC) the effects of the exposure to AFB1 (5-50 µM), FB1 (25-250 µM), and AFB1-FB1 mixtures (MIX) on the in vitro differentiation of regulatory T cells (Treg and Tr1-like) and Th17 cells, as well as elucidate the contribution of aryl hydrocarbon receptor (Ahr) in such effects. AFB1 and mainly MIX induced cytotoxicity in activated CD4 cells via Ahr signaling. AFB1 (5 µM) increased the Treg cell differentiation, but its combination with FB1 (25 µM) also reduced Th17 cell expansion by Ahr-dependent mechanisms. Therefore, this mixture could enhance the Treg/Th17 cell ratio and favor immunosuppression and escape from tumor immunosurveillance to a greater extent than individual mycotoxins. Whereas, AFB1-FB1 mixtures at medium-high doses inhibited the Tr1-like cell expansion induced by the individual mycotoxins and affected Treg and Th17 cell differentiation in Ahr-independent and dependent manners, respectively, which could alter anti-inflammatory and Th17 immune responses. Moreover, individual FB1 altered regulatory T and Th17 cell development independently of Ahr. In conclusion, AFB1 and FB1 interact by modifying Ahr signaling, which is involved in the immunotoxicity as well as in the alteration of the differentiation of Treg, Tr1-like, and Th17 cells induced by AFB1-FB1 mixtures. Therefore, Ahr is implicated in the regulation of the anti- and pro-inflammatory responses caused by the combination of AFB1 and FB1.

A three-gene signature reveals changes in the tumor immune microenvironment in the progression from NAFLD to HCC

Hepatocellular carcinoma (HCC) is one of the most dangerous malignant tumors. The incidence rates of obesity related NAFLD and NASH are increasing year by year, and they are the main risk factors for HCC at present. Finding the mechanism of malignant transformation of NAFLD and NASH is helpful for early prevention and diagnosis. In this study, we performed differential analysis using NAFLD data, NASH data, and HCC data to identify crossover differential genes. Then, using the clinical data of TCGA, a prognostic risk prediction model of three genes (TEAD4, SOCS2, CIT) was constructed, and survival analysis and receiver operating characteristic curves were drawn. The prognostic model was validated using ICGC, GSE116174 and GSE54236 datasets. In addition, we assessed immune status and function in high- and low-risk populations using a prognostic model. Moreover, we assessed the expression of CIT in clinical samples and HCC cell lines and validated its role in HCC development. Our study elucidates the important role of the tumor immune microenvironment in the development of NAFLD/NASH to HCC, deepens the understanding of the pathogenesis of NAFLD/NASH development to HCC, and is helpful for clinical management and decision-making.