Up‐regulation of glycolysis promotes the stemness and EMT phenotypes in gemcitabine‐resistant pancreatic cancer cells

Cancer stem cells ( CSC s) and epithelial–mesenchymal transition ( EMT )‐type cells are considered as underlying causes of chemoresistance, tumour recurrence and metastasis in pancreatic cancer. We aimed to describe the mechanisms – particularly glycolysis – involved in the regulation of the CSC and EMT phenotypes. We used a gemcitabine‐resistant ( GR ) Patu8988 cell line, which exhibited clear CSC and EMT phenotypes and showed reliance on glycolysis. Inhibition of glycolysis using 2‐deoxy‐D‐glucose (2‐ DG ) significantly enhanced the cytotoxicity of gemcitabine and inhibited the CSC and EMT phenotypes in GR cells both in vitro and in vivo . Intriguingly, the use of the reactive oxygen species ( ROS ) scavenger N ‐acetylcysteine ( NAC ) restored the CSC and EMT phenotypes. H 2 O 2 produced changes similar to those of 2‐ DG , indicating that ROS were involved in the acquired cancer stemness and EMT phenotypes of GR cells. Moreover, doublecortin‐like kinase 1 ( DCLK 1), a pancreatic CSC marker, was highly expressed and regulated the stemness and EMT phenotypes in GR cell. Both 2‐ DG and H 2 O 2 treatment suppressed DCLK 1 expression, which was also rescued by NAC . Together, these findings revealed that glycolysis promotes the expression of DCLK 1 and maintains the CSC and EMT phenotypes via maintenance of low ROS levels in chemoresistant GR cells. The glycolysis‐ ROS ‐ DCLK 1 pathway may be potential targets for reversing the malignant behaviour of pancreatic cancer.