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

Hepatocellular carcinoma (HCC), a leading cause of cancer related deaths is predominantly driven by chronic inflammatory responses. Due to asymptomatic nature and lack of early patient biopsies, precise involvement of inflammation in hepatic injury initiation remains unidentified. Aim of the study was to elucidate the regulation patterns of inflammatory signalling from initiation of hepatic injury to development of HCC. HCC mice model was established using DEN followed by repeated doses of CCl(4) and sacrificed at three different stages of disease comprising 7, 14 and 21 weeks. Serum biochemical tests, hepatic lipids quantification, histopathology and qPCR analyses were conducted to characterize the initiation and progression of liver injury and inflammatory signalling. Notably, at 7 weeks, we observed hepatocyte damage and periportal necrotic bodies coupled with induction of Socs2/Socs3 and anti-inflammatory cytokine Il-10. At 14 weeks, mice liver showed advancement of liver injury with micro-vesicular steatosis and moderate collagen deposition around portal zone. With progression of injury, the expression of Socs3 was declined with further reduction of Il-10 and Tgf-β indicating the disturbance of anti-inflammatory mechanism. In contrast, pro-inflammatory cytokines Il1-β, Il6 and Tnf-α were upregulated contributing inflammation. Subsequently, at 21 weeks severe liver damage was estimated as characterized by macro-vesicular steatosis, perisinusoidal collagen bridging, immune cell recruitment and significant upregulation of Col-1α and α-Sma. In parallel, there was significant upregulation of pro/anti-inflammatory cytokines highlighting the commencement of chronic inflammation. Findings of the study suggest that differential regulation of cytokine suppressors and inflammatory cytokines might play role in the initiation and progression of hepatic injury leading towards HCC.