Co-Investigator(Kenkyū-buntansha) |
KUSAKA Masami TAKEDA CHEMICAL INDUSTRIES LTD, CHIEF INVESTIGATOR, 創薬研究本部創薬第二研究所, 主任研究員
MESE Hiroshi GRADUATE SCHOOL OF MEDICINE AND DENTISTRY, OKAYAMA UNIVERSITY, INSTRUCTOR, 大学院・医歯学総合研究科, 助手 (40325098)
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Budget Amount *help |
¥5,400,000 (Direct Cost: ¥5,400,000)
Fiscal Year 2001: ¥1,700,000 (Direct Cost: ¥1,700,000)
Fiscal Year 2000: ¥3,700,000 (Direct Cost: ¥3,700,000)
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Research Abstract |
Humoral hypercalcemia of malignancy (HHM) causes a decline in the quality of life of cancer patients. We previously demonstrated that the angiogenesis inhibitor, TNP-470, inhibited not only tumor growth but also oeteoclastic bone resorption. It is suggested that TNP-470 has a possibility of therapeutic use for the treatment of the HHM. In the present study, we investigated the mechanism of TNP-470 on the bone metabolism and clinical approach for HHM. Effects of TNP-470 for hypercalcemia in vivo We employed a hypercalcemia model using a human oral squamous cell carcinoma OCC-1 secreting PTHrP. In the therapeutic treatment, TNP-470 was administerd subcutaneously after the definition of hypercalcemia. In the prophylactic treatment, TNP-470 was given before manifestation of hypercalcemia. In both treatments, TNP-470 markedly suppressed the increase of blood Ca^<2+>. Particularly in the prophylactic treatment, TNP-470 significantly inhibited the progression of the tumor growth and prolonged t
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he survival. In another experimental hypercalcemia model induced by PTHrP and IL-1β, TNP-470 also suppressed hypercalcemia. Effects of angiogenesis inhibitors on osteoclasts formation in vitro In a murine bone marrow culture under VitD_3, not only TNP-470 but also Angiostatin, Ursolic acid suppressed osteoclasts formation. However, other angiogenesis inhibitors, didn't suppress osteoclasts formation. Mechanism of the inhibitory effects on the osteoclasts formation of TNP-470 TNP-470 suppressed osteoclasts formation, but didn't affect bone resorption activity of osteoclasts. TNP-470 didn't affect the expression of RANKL, OPG, and M-CSF mRNA in bone marrow/ stromal cells. Inhibitory effects of cell proliferation and Cytotoxicity of TNP-470 In various types of cells, TNP-470 suppressed cell proliferation and showed cytotoxicity at a high concentration. From these results, TNP-470 didn't suppress osteoclasts formation because of cytotoxicity. These data suggested that TNP-470, which possessed both antitumor action and osteoclast-inhibitory activity, should be a beneficial drug not only for HHM but also other cancer-induced bone diseases. Less
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