Differential bioenergetic reprogramming driven by sorafenib reveals therapeutic vulnerabilities in biliary tract cancers.

Biliary tract cancers (BTCs) comprise biologically heterogeneous subtypes with limited therapeutic options and variable responses to sorafenib. The biological basis underlying this variability remains unclear. In this study, we compared intrahepatic cholangiocarcinoma (iCCA) and gallbladder cancer (GBC) models under defined sorafenib exposure conditions using transcriptomic profiling, Seahorse-based mitochondrial stress assays, pharmacologic combination analysis, and patient-derived organoid models. In representative iCCA models, 1.25 μM sorafenib increased mitochondrial respiration and ATP production, whereas 10 μM sorafenib suppressed this respiratory adaptation. In contrast, representative GBC models exhibited persistent suppression of mitochondrial respiratory function across the tested conditions and did not display a comparable concentration-dependent shift. Integrated transcriptomic and pharmacologic analyses further identified mitochondrial Complex I as a treatment-relevant vulnerability under sorafenib exposure, with stronger combination interactions observed in iCCA models. These findings indicate that iCCA and GBC differ in their metabolic responses to sorafenib and highlight subtype-specific differences in mitochondrial adaptation under treatment stress.