Effect of LPS-induced M1 polarization of macrophages on tumor growth / 中国现代医生

ABSTRACT

Objective To study the effect of lipopolysaccharide(LPS)-induced M1 polarization of macrophages on tumor growth.Methods Female Balb/c mice were randomly divided into control group and experimental group.Renca cells were used to establish subcutaneous tumor model.NaCl(100μl/mice,once every two days)or LPS(100μg/mice,once every two days)was injected to the tumor side when the tumor grew to 50mm3.The M1 polarization level of tumor-associated macrophages was detected by flow cytometry.Mouse tumor cell lines(ML-1,MC38,Renca)were divided into three groupsblank group(complete medium with 50％DMEM basal medium),control group(complete medium with 50％medium supernatant of cultured macrophages)and experimental group(complete medium with 50％medium supernatant of LPS pretreated cultured macrophages).The proliferation of tumor cells was detected by cell counting kit-8(CCK-8).The cell cycle and apoptosis of tumor cells were detected by flow cytometry.Results The proportion of tumor-associated macrophages M1 increased after LPS treatment(P<0.001),thus enhancing its anti-tumor function.LPS-induced M1 polarization of macrophages can significantly inhibit the proliferation of tumor cells(RencaP=0.023,ML-1P=0.045).LPS-induced M1 polarization of macrophages blocked G0/G1 phase(MC38P=0.011,ML-1P=0.022)or S phase(RencaP=0.022)of tumor cell cycle,and then cell division was inhibited.LPS-induced M1 polarization of macrophages significantly induced apoptosis of tumor cells(RencaP=0.04,ML-1P=0.007).Conclusion LPS can play an anti-tumor role by inducing M1 polarization of macrophages.