Models of nonalcoholic steatohepatitis potentiated by chemical inducers leading to hepatocellular carcinoma

Hepatocellular carcinoma (HCC), the most common primary liver cancer, arises after a long period of exposure to etiological factors. Nonalcoholic steatohepatitis (NASH) is ranked as the main risk factor for developing HCC; hence, experimental models of NASH leading to HCC have become key tools both to investigate the molecular mechanisms underlying the pathophysiology and to evaluate new putative drugs for treating chronic liver diseases in humans. Animal models of NASH induced by a high-fat diet (HFD) plus chemical inducers, such as the NASH-HCC (STAM), high-fat diet/diethylnitrosamine (HFD/DEN), choline-deficient high-fat diet/DEN (CDHFD/DEN), and Western diet/carbon tetrachloride (WD/CCl4) models, are promising because they exacerbate liver damage and significantly shorten the experimental time. In this review, we critically summarize and discuss the ability of these models to recapitulate the liver alterations that precede and lead to HCC progression, as well as the impact of the diet in promoting liver injury progression. We also emphasize the strengths and weaknesses of the models' ability to closely mimic the stages of liver injury development that occur in humans. Based on the molecular mechanisms induced by the currently available NASH models leading to HCC, we argue that although several NASH models have importantly contributed to describing the disease chronology, the progress in emulating the progression from NASH to HCC has been partial. Thus, the development of novel NASH/HCC models remains an unmet need.