A comparative study of the chemotoxic effects of idarubicin and doxorubicin in a chemically-induced in vivo mouse model and in vitro models for hepatocellular carcinoma.

Hepatocellular carcinoma (HCC) is a significant clinical challenge, with limited therapeutic options. Anthracyclines such as doxorubicin (DOX) and idarubicin (IDA) are commonly used in cancer treatment but have shown variable efficacy and side effects in HCC. This study aimed to compare the cytotoxic effects of DOX and IDA on HCC in both in vivo and in vitro models, assess their impact on the tumor and its microenvironment, as well as identify potential adverse effects. In vivo, both DOX and IDA treatments led to a significant reduction in body weight and spleen-to-body weight ratio, with IDA showing a more pronounced effect. However, neither treatment significantly affected intestinal morphology, compared to untreated mice with HCC. None of the treatments had a significant impact on macroscopic or microscopic tumor burden. Notably, DOX and IDA treatments resulted in a significant reduction in collagen deposition and liver fibrosis. DOX reduced hepatic stellate cell (HSC) activation, despite having no significant impact on the expression levels of fibrotic markers TGF-{beta} and CTGF. In contrast, IDA not only increased HSC activation but also upregulated TGF-{beta} and CTGF expression in both tumor and peritumoral tissues. Molecular analysis further revealed that DOX and IDA treatments increased mRNA levels of ER-stress and proliferation markers in non-tumor tissues, with significant findings within the PERK pathway. IDA, in particular, induced higher ATF4 expression in hepatocytes and enhanced macrophage recruitment in tissue sections. While DOX and IDA exhibit limited effectiveness in reducing HCC tumor burden in vivo, the in vitro analyses showed that DOX and IDA demonstrated strong, concentration-dependent cytotoxicity, significantly reducing cell viability in all tested HCC cell lines. Increasing complexity of the in vitro models, by culturing in 3D and adding HSCs, decreased the sensitivity to the anthracyclines. This, along with the effects on liver fibrosis, stellate cell activation and inflammation seen in vivo, may be the result of the significant contribution of the tumor microenvironment in mediating drug response. The differential expression of ER-stress and proliferation markers, particularly in the PERK pathway, further highlights the complexity of the tumor microenvironments influence on treatment outcomes. More research into these molecular responses and underlying mechanisms is needed to provide insights into improving therapeutic strategies for HCC.