title: In vitro evaluation of inhibitory effect of nuclear factor-kappaB activity by small interfering RNA on pro-tumor characteristics of M2-like macrophages.
abstract: Tumor-associated macrophages (TAMs) have an alternatively activated macrophage phenotype (M2) and promote cancer cell proliferation, angiogenesis and metastasis. Nuclear factor-kappaB (NF-κB) is one of the master regulators of macrophage polarization. Here, we investigated the effect of inhibition of NF-κB activity by small interfering RNA (siRNA) on the pro-tumor response of macrophages located in the tumor microenvironment in vitro. We used mouse peritoneal macrophages cultured in conditioned medium from colon-26 cancer cells as an in vitro TAM model (M2-like macrophages). Transfection of NF-κB (p50) siRNA into M2-like macrophages resulted in a significant decrease in the secretion of interleukin (IL)-10 (a T helper 2 (Th2) cytokine) and a significant increase of T helper 1 (Th1) cytokine production (IL-12, tumor necrosis factor-α, and IL-6). Furthermore, vascular endothelial growth factor production and matrix metalloproteinase-9 mRNA expression in M2-like macrophages were suppressed by inhibition of NF-κB expression with NF-κB (p50) siRNA. In addition, there was a reduction of arginase mRNA expression and increase in nitric oxide production. The cytokine secretion profiles of macrophages cultured in conditioned medium from either B16BL6 or PAN-02 cancer cells were also converted from M2 to classically activated (M1) macrophages by transfection of NF-κB (p50) siRNA. These results suggest that inhibition of NF-κB activity in M2-like macrophages alters their phenotype toward M1.
authors.affiliation: Department of Drug Delivery Research, Graduate School of Pharmaceutical Sciences, Kyoto University.
authors.forename: Yusuke
authors.initials: Y
authors.lastname: Kono
authors.forename: Shigeru
authors.initials: S
authors.lastname: Kawakami
authors.forename: Yuriko
authors.initials: Y
authors.lastname: Higuchi
authors.forename: Fumiyoshi
authors.initials: F
authors.lastname: Yamashita
authors.forename: Mitsuru
authors.initials: M
authors.lastname: Hashida
mesh_terms: D000818:Animals; D001119:Arginase / Q000235:genetics / Q000378:metabolism; D045744:Cell Line, Tumor; D003110:Colonic Neoplasms / Q000235:genetics / Q000378:metabolism*; D016207:Cytokines / Q000378:metabolism*; D007378:Interleukins / Q000378:metabolism; D008070:Lipopolysaccharides; D008262:Macrophage Activation; D008264:Macrophages / Q000378:metabolism*; D017737:Macrophages, Peritoneal / Q000378:metabolism*; D020780:Matrix Metalloproteinase 9 / Q000378:metabolism; D051379:Mice; D016328:NF-kappa B / Q000037:antagonists & inhibitors*; D009389:Neovascularization, Pathologic; D009569:Nitric Oxide / Q000378:metabolism; D010641:Phenotype; D012333:RNA, Messenger / Q000378:metabolism; D034741:RNA, Small Interfering / Q000378:metabolism*; D015398:Signal Transduction; D018417:Th1 Cells / Q000378:metabolism; D014162:Transfection; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism; D042461:Vascular Endothelial Growth Factor A / Q000378:metabolism
chemical_list: D016207:Cytokines; D007378:Interleukins; D008070:Lipopolysaccharides; D016328:NF-kappa B; D012333:RNA, Messenger; D034741:RNA, Small Interfering; D014409:Tumor Necrosis Factor-alpha; D042461:Vascular Endothelial Growth Factor A; C467480:vascular endothelial growth factor A, mouse; D009569:Nitric Oxide; D020780:Matrix Metalloproteinase 9; D001119:Arginase