Glucose depletion enhances the stem cell phenotype and gemcitabine resistance of cholangiocarcinoma organoids through AKT phosphorylation and reactive oxygen species

Cancer cells are strongly dependent on the glycolytic pathway for generation of energy even under aerobic condition through a phenomenon known as the Warburg effect. Rapid proliferation of cancer cells is often accompanied by high glucose consumption and abnormal angiogenesis, which may lead to glucose depletion. In the present study, we investigated how cholangiocarcinoma cells adapt to glucose depletion using a 3D organoid culture system. We cultured organoids derived from cholangiocarcinoma under glucose-free condition and investigated cell proliferation, expression of stem cell markers and resistance to gemcitabine. Cholangiocarcinoma organoids cultured under glucose-free condition showed reduced proliferation but were able to survive. We also observed an increase in the expression of stem cell markers including LGR5 and enhancement of stem cell phenotypic characteristics such as resistance to gemcitabine through AKT phosphorylation and reactive oxygen species. These findings indicate that cholangiocarcinoma cells are able to adapt to glucose depletion through enhancement of their stem cell phenotype in response to changes in microenvironmental conditions.