Division of Biochemical Pharmacology, Department of Basic Medical Research, Ehime University Graduate School of Medicine, Toon City, Ehime 791-0295, Japan.
Division of Functional Histology, Department of Functional Biomedicine, Ehime University Graduate School of Medicine, Toon City, Ehime 791-0295, Japan.
Eur J Pharmacol. 2015 Jan 5;746:115-25. doi: 10.1016/j.ejphar.2014.10.048. Epub 2014 Nov 6.
Tumor growth and metastasis are closely associated with the M2 macrophage activation of tumor-associated macrophages (TAMs) in the tumor microenvironment as well as the development of tumor cells. In this study, we examined the antiproliferative, antitumor, and antimetastatic effects of three dihydroxycoumarins (esculetin, fraxetin, and daphnetin) against osteosarcoma LM8 cells (in vitro) and a highly metastatic model in LM8-bearing mice (in vivo). Esculetin (20-100μM) inhibited the proliferation of LM8 cells, whereas fraxetin and daphnetin had no effect. Esculetin inhibited the expressions of cyclin D1, cyclin-dependent kinase (CDK) 4 and matrix metalloproteinase (MMP)-2, and production of both transforming growth factor (TGF)-β1 and vascular endothelial growth factor (VEGF) in LM8 cells. Esculetin (3 or 10mg/kg) and fraxetin (10mg/kg) inhibited tumor growth and metastasis to the lung or liver, whereas daphnetin did not. These results suggested that the antitumor and antimetastatic actions of esculetin may be partly attributed to G1 arrest by the inhibition of cyclin D1 and CDK4 expression, while its antiangiogenic action may have been due to the inhibition of MMP-2 expression and TGF-β1 and VEGF productions at tumor sites. Esculetin (10-100μM) and fraxetin (50-100μM) inhibited the production of interleukin (IL)-10, monocyte chemoattractant protein (MCP)-1, and TGF-β1 during the differentiation of M2 macrophages by reducing the phosphorylation of Stat 3 without affecting its expression. These results also suggested that the antitumor and antimetastatic actions of esculetin or fraxetin may be due to the regulated activation of TAM by M2 macrophage differentiation in the tumor microenvironment.
肿瘤生长和转移与肿瘤相关巨噬细胞（TAMs）中 M2 巨噬细胞的激活以及肿瘤细胞的发展密切相关。在这项研究中，我们研究了三种二羟基香豆素（esculetin、fraxetin 和 daphnetin）对骨肉瘤 LM8 细胞（体外）和 LM8 荷瘤小鼠高度转移模型（体内）的抗增殖、抗肿瘤和抗转移作用。Esculetin（20-100μM）抑制 LM8 细胞的增殖，而 fraxetin 和 daphnetin 则没有作用。Esculetin 抑制了 cyclin D1、细胞周期蛋白依赖性激酶（CDK）4 和基质金属蛋白酶（MMP）-2 的表达，以及转化生长因子（TGF）-β1 和血管内皮生长因子（VEGF）在 LM8 细胞中的产生。Esculetin（3 或 10mg/kg）和 fraxetin（10mg/kg）抑制肿瘤生长和向肺或肝的转移，而 daphnetin 则没有。这些结果表明，esculetin 的抗肿瘤和抗转移作用部分归因于通过抑制 cyclin D1 和 CDK4 的表达导致 G1 期阻滞，而其抗血管生成作用可能是由于抑制 MMP-2 的表达以及 TGF-β1 和 VEGF 在肿瘤部位的产生。Esculetin（10-100μM）和 fraxetin（50-100μM）通过减少 Stat 3 的磷酸化而不影响其表达，抑制 M2 巨噬细胞分化过程中白细胞介素（IL）-10、单核细胞趋化蛋白（MCP）-1 和 TGF-β1 的产生。这些结果还表明，esculetin 或 fraxetin 的抗肿瘤和抗转移作用可能是由于在肿瘤微环境中调节 M2 巨噬细胞分化激活 TAM 所致。
