Antitumor and antimetastatic actions of dihydroxycoumarins (esculetin or fraxetin) through the inhibition of M2 macrophage differentiation in tumor-associated macrophages and/or G1 arrest in tumor cells

• Published in: European journal of pharmacology Vol. 746; pp. 115 - 125
• Main Authors: Kimura, Yoshiyuki, Sumiyoshi, Maho
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 05.01.2015
• Subjects: Animals; Antimetastatic; Antineoplastic Agents - pharmacology; Antitumor; Apoptosis - drug effects; Body Weight - drug effects; Cell Differentiation - drug effects; Cell Line, Tumor; Cell Polarity - drug effects; Cell Proliferation - drug effects; Chemokine CCL2 - biosynthesis; Coumarins - pharmacology; Cyclin-Dependent Kinase 4 - metabolism; Dihydroxycoumarins; G1 arrest; G1 Phase Cell Cycle Checkpoints - drug effects; Gene Expression Regulation, Neoplastic - drug effects; Humans; Interleukin-10 - biosynthesis; M2 macrophage; Macrophage Activation - drug effects; Macrophages - cytology; Macrophages - drug effects; Male; Matrix Metalloproteinase 2 - metabolism; Mice; Neoplasm Metastasis; Osteosarcoma - pathology; Stat 3 phosphorylation; STAT3 Transcription Factor - metabolism; Tetradecanoylphorbol Acetate - pharmacology; Transforming Growth Factor beta1 - biosynthesis; Umbelliferones - pharmacology; Vascular Endothelial Growth Factor A - biosynthesis; Xenograft Model Antitumor Assays; Dihydroxycoumarins; M2 macrophage; Stat 3 phosphorylation; Antimetastatic; G1 arrest; Antitumor; G arrest
• ISSN: 0014-2999; 1879-0712
• DOI: 10.1016/j.ejphar.2014.10.048

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. [Display omitted]