HLF transactivates TFEB to promote gallbladder cancer stem cells' self-renewal and determines tumor response to distinct therapies.

Gallbladder cancer (GBC) is the most common malignancy in the biliary system and lacks biomarkers for personalized therapy. Here, we reported that hepatic leukemia factor (HLF) was highly expressed in gallbladder cancer stem cells (CSCs) and patients with gemcitabine-resistant GBC. Mechanistic study revealed that interleukin-6 receptor (IL-6R) and transcription factor EB (TFEB) are direct target genes of HLF. The IL-6/IL-6R/signal transducer and activator of transcription 3 axis transactivates HLF expression in GBC, forming a positive feedback loop. Functional studies revealed that HLF promoted gallbladder CSCs' expansion and gemcitabine resistance via TFEB-induced autophagy. In addition, HLF drives TFEB-induced programmed death ligand 1 expression in human tumors and governs tumor immune evasion in a CD8(+) T cell-dependent manner. Patient cohorts' analysis suggested that HLF levels in GBCs might determine the distinct responses to chemotherapy and immunotherapy. In conclusion, our findings demonstrated that HLF could act as a driver for gallbladder CSCs' self-renewal and drug resistance and a biomarker for individualized therapy.