Objective To investigate the effect of tumor-associated macrophage exosomes on glycolysis of pancreatic cancer cells and its mechanism.Methods The THP-1 cells were induced to differentiate into the M0 and M2 macrophages,and the exosomes(M0 exo and M2 exo)were extracted.The pancreatic cancer cells CAPAN-2 and ASPC-1 were divided into the PBS group,the M0 exo group,the M2 exo group and the M2 exo+siKRAS group,and co-incubated with equal volumes of PBS,10 μg/mL of M0 exo,10 μg/mL of M2 exo,and transfection of KRAS siRNA and 10 μg/mL of M2 exo,respectively.Transmission electron microscopy was used to observe the structure of exosomes;CCK-8 was used to detect the cell proliferation capacity;the kit was used to detect the glucose uptake rate and production level of lactic acid,and Western blot was used to detect the exosome markers expression,KRAS protein expression and ERK1/2 phosphorylation level.Results THP-1 was induced to differentiate into M2 macrophages expressing Arg-1 and IL-10 marker proteins.M0 exo and M2 exo had a bilayer membrane structure with a particle size of about 100 nm and expressed exosomal marker proteins of CD9,CD81,and TSG101.Compared with the PBS group,the cell proliferation,glucose uptake rate,production level of lactic acid of CAPAN-2 and ASPC-1 cells in the M2 exo group increased significantly(P<0.05),and the KRAS expression and ERK1/2 phosphorylation level were significantly increased(P<0.001).Compared with the M2 exo group,the proliferation,glucose uptake rate and production level of lactic acid of CAPAN-2 and ASPC-1 cells in the M2 exo+siKRAS group decreased significantly(P<0.05).Conclusion Tumor-associated macrophage exosomes can promote the glycolysis of pancreatic cancer cells via the activation of KRAS signaling pathway.