title: Tumor associated osteoclast-like giant cells promote tumor growth and lymphangiogenesis by secreting vascular endothelial growth factor-C.
abstract: Tumors with osteoclast-like giant cells (OGCs) have been reported in a variety of organs and exert an invasive and prometastatic phenotype, but the functional role of OGCs in the tumor environment has not been fully clarified. We established tumors containing OGCs to clarify the role of OGCs in tumor phenotype. A mixture of HeLa cells expressing macrophage colony-stimulating factor (M-CSF, HeLa-M) and receptor activator of nuclear factor-κB ligand (RANKL, HeLa-R) effectively supported the differentiation of osteoclast-like cells from bone marrow macrophages in vitro. Moreover, a xenograft study showed OGC formation in a tumor composed of HeLa-M and HeLa-R. Surprisingly, the tumors containing OGCs were significantly larger than the tumors without OGCs, although the growth rates were not different in vitro. Histological analysis showed that lymphangiogenesis and macrophage infiltration in the tumor containing OGCs, but not in other tumors were accelerated. According to quantitative PCR analysis, vascular endothelial growth factor (VEGF)-C mRNA expression increased with differentiation of osteoclast-like cells. To investigate whether VEGF-C expression is responsible for tumor growth and macrophage infiltration, HeLa cells overexpressing VEGF-C (HeLa-VC) were established and transplanted into mice. Tumors composed of HeLa-VC mimicked the phenotype of the tumors containing OGCs. Furthermore, the vascular permeability of tumor microvessels also increased in tumors containing OGCs and to some extent in VEGF-C-expressing tumors. These results suggest that macrophage infiltration and vascular permeability are possible mediators in these tumors. These findings revealed that OGCs in the tumor environment promoted tumor growth and lymphangiogenesis, at least in part, by secreting VEGF-C.
authors.affiliation: Department of Cellular Physiological Chemistry, Tokyo Medical and Dental University, 1-5-45, Yushima, Bunkyo-ku, Tokyo 113-8510, Japan; Department of Cardivascular Medicine, Tokyo Medical and Dental University, 1-5-45, Yushima, Bunkyo-ku, Tokyo 113-8510, Japan.
authors.forename: Yu
authors.initials: Y
authors.lastname: Hatano
authors.affiliation: Department of Cellular Physiological Chemistry, Tokyo Medical and Dental University, 1-5-45, Yushima, Bunkyo-ku, Tokyo 113-8510, Japan. Electronic address: nakacell@tmd.ac.jp.
authors.forename: Ken-ichi
authors.initials: K
authors.lastname: Nakahama
authors.affiliation: Department of Cardivascular Medicine, Tokyo Medical and Dental University, 1-5-45, Yushima, Bunkyo-ku, Tokyo 113-8510, Japan.
authors.forename: Mitsuaki
authors.initials: M
authors.lastname: Isobe
authors.affiliation: Department of Cellular Physiological Chemistry, Tokyo Medical and Dental University, 1-5-45, Yushima, Bunkyo-ku, Tokyo 113-8510, Japan.
authors.forename: Ikuo
authors.initials: I
authors.lastname: Morita
mesh_terms: D000818:Animals; D002199:Capillary Permeability / Q000235:genetics / Q000502:physiology; D015726:Giant Cells / Q000473:pathology* / Q000502:physiology*; D006367:HeLa Cells; D064593:Heterografts; D006801:Humans; D042583:Lymphangiogenesis / Q000235:genetics / Q000502:physiology; D016173:Macrophage Colony-Stimulating Factor / Q000235:genetics / Q000378:metabolism; D008264:Macrophages / Q000473:pathology / Q000502:physiology; D008297:Male; D051379:Mice; D018345:Mice, Knockout; D009374:Neoplasms, Experimental / Q000235:genetics / Q000473:pathology* / Q000503:physiopathology*; D010010:Osteoclasts / Q000473:pathology* / Q000502:physiology*; D053245:RANK Ligand / Q000235:genetics / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D012334:RNA, Neoplasm / Q000235:genetics / Q000378:metabolism; D059016:Tumor Microenvironment / Q000235:genetics / Q000502:physiology; D042582:Vascular Endothelial Growth Factor C / Q000235:genetics / Q000502:physiology*
chemical_list: D053245:RANK Ligand; D012333:RNA, Messenger; D012334:RNA, Neoplasm; C505688:TNFSF11 protein, human; C467486:VEGFC protein, human; D042582:Vascular Endothelial Growth Factor C; D016173:Macrophage Colony-Stimulating Factor
keywords: Osteoclast-like giant cell; RANKL; VEGF-C