The effect of TSN on macrophage polarization. (a) The comparisons of mRNA levels of cytokines from THP-1 stimulated by TSN of Panc-1-treated with electric fields. The mRNA levels of M1 markers increased along with the increasing electric fields, while the mRNA levels of M2 markers did not show a continuous increase along with the increasing electric fields. (b) The expression of surface markers of THP-1 stimulated by TSN of Bxpc-3 treated with electric fields. Increased expression of HLA-DR on THP-1 along with the increasing electric fields was observed. (c) IRE could increase infiltration of M1 macrophage in pancreatic tumor tissue (IHC). Orthotopic or subcutaneous tumor tissue was used as control. (d) IRE could increase the expression of CD16/32 in infiltrated macrophages in pancreatic tumor tissue. Orthotopic or subcutaneous tumor tissue was used as control. F4/80 was used to indicate macrophage; CD16/32 was the marker of M1 macrophage; CD206 was the marker of M2 macrophage; DAPI was used to indicate the nuclear of cells. (e) The expression of CD16/32 in macrophage from tumor tissue, spleen, peripheral blood, and lymph node in an orthotopic model of mouse pancreatic cancer after IRE treatment. IRE increased the expression of CD16/32 on the surface of macrophages from these tissues in the orthotopic model of mouse pancreatic cancer. (f) The expression of CD16/32 in macrophages from tumor tissue, spleen, peripheral blood, and lymph node in the subcutaneous model of mouse pancreatic cancer after IRE treatment. IRE increased the expression of CD16/32 on the surface of macrophages from these tissues in the subcutaneous model of mouse pancreatic cancer. Orthotopic or subcutaneous tumors from the sham operation group were used as control. One-way analysis of variance (ANOVA) with Bonferroni comparison test was performed. * p < .05, **, p < .01, ***, p < .001, NS. not significant