Neonatal streptozotocin treatment causes type 1 diabetes and subsequent hepatocellular carcinoma in DIAR mice fed a normal diet

Purpose: Hepatocellular carcinoma (HCC) represents a major health challenge because of its increasing morbidity and mortality. The establishment of useful models of HCC can significantly contribute to unveiling its pathophysiology. We developed a novel mouse model of HCC based on type 1 diabetes and reported its histopathological features. Methods: Newborn male ddY, Institute for Animal Reproduction (DIAR) mice were divided into two groups on the basis of streptozotocin treatment, which induces type 1 diabetes. Streptozotocin was subcutaneously injected (60 mg/g) into the treated group (DIAR-nSTZ mice), whereas physiologic solution was injected into the control group (DIAR-control mice) at 1.5 days after birth. All mice were fed a normal diet and histopathologically assessed at 6, 8, 10, 12, 19, and 27 weeks of age. Results: At 8 weeks, small hepatocytic nodules with mild to moderate cellular atypia were observed in the livers of DIAR-nSTZ mice, which progressed to large hepatocytic nodules with cellular atypia and infiltrating growth at 12 weeks, identical to those in well-differentiated human HCC. At 19 and 27 weeks, moderately differentiated HCC was observed in all DIAR-nSTZ mice. Conversely, no neoplastic findings were evident in DIAR-control mice. No steatosis or fibrosis was evident in either group. Immunohistochemical analysis revealed that all nodules observed in DIAR-nSTZ mice were positive for glutamine synthetase. Conclusions: In DIAR-nSTZ mice, the development of HCC with similarity to human HCC and high reproducibility can be achieved using a short and simple protocol. We believe that this model will be useful for studying liver carcinogenesis.