The progression of metabolic dysfunction-associated steatotic liver disease toward hepatocellular carcinoma in an efficient rat model

Metabolic dysfunction-associated steatotic liver disease (MASLD) has emerged as a critical worldwide public health issue and is among the main risk factors for hepatocellular carcinoma (HCC) development; however, although some experimental models have been proposed, the recapitulation of the chronological progression from MASLD to HCC remains an unmet need. We aimed to establish an efficient MASLD model leading to HCC, named the MACER (MASLD-CANCER) model. Six-week-old male Fischer 344 rats, weighing 100-120 g, were fed a hepatopathogenic (HPG) diet containing high levels of fat, sucrose, and cholesterol in combination with low doses of CCl₄ and diethylnitrosamine (DEN). Hepatosteatosis, inflammation, fibrosis, and HCC markers were assessed. The evidence revealed that the MACER model induced an altered lipid metabolism profile, promoted hepatosteatosis, and increased liver injury, inflammation, and cellular senescence beginning the third week after exposure to hepatotoxins. In addition, this model showed expression of the proliferation marker Ki-67 at seven weeks and induction of collagen deposition and expression of HCC markers, such as GGT and GSTP1, from 13 weeks onward. Moreover, our model progressed to advanced HCC stages even after removing hepatotoxins. The MACER model is a novel and useful tool for investigating chronological MASLD toward HCC progression and for assessing the efficacy of chemopreventive agents.