Heterogeneity, Inherent and Acquired Drug Resistance in Patient-Derived Organoids Models of Primary Liver Cancer

To screen for sensitive drugs for recurrent primary liver cancer (PLC) and elucidate the mechanisms underlying inherent and acquired drug resistance, we established a platform of organoids, organoids-derived xenograft (ODX) mouse models, and patient-derived xenograft (PDX) mouse models of primary liver cancer (PLC). Fifty-two organoids were established from 153 PLC patients. Establishing organoids of hepatocellular carcinoma (HCC) displayed a trend toward a higher success rate than establishing PDX (29.0% vs. 23.7%) and took a shorter duration (13.0 ± 4.7 vs. 25.1 ± 5.4 days, P=2.28×10−13) than establishing PDX models. Larger tumor, vascular invasion, and advanced stage were significantly associated with successful establishment of organoids and PDX in HCC. Organoids and ODX recapitulated PLC histopathological features but enriched more aggressive cell types. PLC organoids were mostly resistant to lenvatinib in vitro but sensitive in ODX model, indicating innate immunity plays a role. Acquired sorafenib-resistant HCC organoids were generated via 3–5 months of induction. RNA-sequencing indicated that stemness– and epithelial–mesenchymal transition (EMT)–related gene sets were upregulated, whereas liver development– and liver specific molecule–related gene sets were downregulated, in acquired sorafenib-resistant organoids. Targeting mTOR signaling pathway was effective in treating acquired sorafenib-resistant HCC, possibly via inducing phosphorylated S6 kinase. Genes upregulated in acquired sorafenib-resistant HCC organoids were often associated with unfavorable prognosis. Conclusively, HCC organoids perform better than PDX for drug selection. Acquired sorafenib resistance in organoids promotes HCC aggressiveness via facilitating the stemness, retrodifferentiation, and EMT. Phosphorylated S6 kinase might be predictive for drug resistance in HCC.