ZEB1 stratifies the response to Sorafenib and Mdivi-1 combination therapy in hepatocellular carcinoma

Primary liver cancer is one of the most frequently diagnosed and deadliest cancers. Zinc finger E-box binding homeobox 1 (ZEB1) is negative prognostic factor in liver cancer by promoting therapy resistance and tumorigenesis. Interfering in pathways of cellular metabolism emerges as a potent strategy to overcome tumor cells resistance to therapy. Our study aims to investigate the apoptotic potential of pharmacological inhibition of mitochondrial metabolism in primary liver cancer and whether this strategy can reduce ZEB1-associated resistance to standard of care chemotherapy Sorafenib. ZEB1 mRNA levels in patient samples and cancer cell lines were computationally screened using public datasets. Transcript and protein abundance of ZEB1 and regulators of mitochondrial fission and fusion were quantified in patient-matched tumor and non-tumor tissues of hepatocellular carcinoma (HCC) and cholangiocellular adenocarcinoma (CCA) from our clinic and common liver cancer cell lines. Functional assays on cell models with varying ZEB1 expression exposed to mitochondrial division inhibitor Mdivi-1 included mitochondrial mass quantification, mitochondrial membrane potential examination, apoptosis, extracellular flux, and cell growth analyses. Mdivi-1 treatment in human-physiological achievable concentration effectively induced apoptosis in all tested cell models. ZEB1 expression was heightened in younger patients, and dynamin-related protein 1 (Drp1) protein abundance was elevated in a subgroup of tumor tissue compared to healthy tissue. Cancer cell lines with high ZEB1 expression showed increased mitochondrial fission marker Drp1 and larger total mitochondrial mass, preserved membrane potential with reduced mitochondrial ATP production and respiration, resulting in an overall reduced mitochondrial fitness. Pharmacological inhibition of mitochondrial fission using Mdivi-1 reduced HCC resistance to Sorafenib in ZEB1-driven liver cancer. A subset of HCC cell lines with elevated ZEB1 levels exhibit increased mitochondrial mass and reduced metabolic activity. Targeting mitochondrial division in HCC by treatment with Mdivi-1 in combination with Sorafenib demonstrates a synergistic therapeutic effect in hepatocellular carcinoma (HCC) cell lines characterized by high ZEB1 expression. Further in vivo validation is needed to confirm these findings and evaluate this potential combined treatment option.