o-(chloroacetylcarbamoyl)fumagillol and Bone-Neoplasms

Bone neoplasms, such as osteosarcoma, exhibit a propensity for systemic metastases resulting in adverse clinical outcome. Traditional treatment consisting of aggressive chemotherapy combined with surgical resection, has been the mainstay of these malignances. Therefore, bone-targeted non-toxic therapies are required. We previously conjugated the aminobisphosphonate alendronate (ALN), and the potent anti-angiogenic agent TNP-470 with N-(2-hydroxypropyl)methacrylamide (HPMA) copolymer. HPMA copolymer-ALN-TNP-470 conjugate exhibited improved anti-angiogenic and anti-tumor activity compared with the combination of free ALN and TNP-470 when evaluated in a xenogeneic model of human osteosarcoma. The immune system has major effect on toxicology studies and on tumor progression. Therefore, in this manuscript we examined the safety and efficacy profiles of the conjugate using murine osteosarcoma syngeneic model. Toxicity and efficacy evaluation revealed superior anti-tumor activity and decreased organ-related toxicities of the conjugate compared with the combination of free ALN plus TNP-470. Finally, comparative anti-angiogenic activity and specificity studies, using surrogate biomarkers of circulating endothelial cells (CEC), highlighted the advantage of the conjugate over the free agents. The therapeutic platform described here may have clinical translational relevance for the treatment of bone-related angiogenesis-dependent malignances.

Topics: Acrylamides; Alendronate; Angiogenesis Inhibitors; Animals; Antineoplastic Agents; Body Weight; Bone Density Conservation Agents; Bone Neoplasms; Cell Line, Tumor; Cyclohexanes; Humans; Male; Materials Testing; Mice; Mice, Inbred BALB C; Molecular Structure; O-(Chloroacetylcarbamoyl)fumagillol; Osteosarcoma; Polymers; Sesquiterpenes; Tissue Distribution

Early relapse with distant metastasis often is observed in patients with cancer after resection of the primary tumor. It is considered that resection of the primary tumor induces activation of systemic angiogenesis and enhances progression of remote metastasis. The authors show that resection of the primary osteosarcoma tumor enhances progression of pulmonary metastasis in animal osteosarcoma models. Matrigel plug neovascularization assay revealed that systemic angiogenic activity was elevated after primary tumor removal (tumor intact group, 1.61 +/- 0.21 g/dL; tumor removed group, 4.92 +/- 0.35 g/dL). In addition, serum concentration of the angiogenesis inhibitor, endostatin, decreased significantly after primary tumor removal. Treatment with the antiangiogenic reagent TNP-470 suppressed postoperative progression of pulmonary metastasis. These results indicate the possibility that activation of angiogenic activity after resection of osteosarcoma tumors enhances progression of pulmonary metastasis. The current data also suggest that administration of antiangiogenic reagents can prevent progression of pulmonary metastasis in osteosarcoma postoperatively.

Topics: Angiogenesis Inhibitors; Animals; Bone Neoplasms; Collagen; Cyclohexanes; Disease Models, Animal; Endostatins; Endothelial Growth Factors; Female; Intercellular Signaling Peptides and Proteins; Lung Neoplasms; Lymphokines; Mice; Mice, Inbred BALB C; O-(Chloroacetylcarbamoyl)fumagillol; Osteosarcoma; Peptide Fragments; Postoperative Complications; Sesquiterpenes; Vascular Endothelial Growth Factor A; Vascular Endothelial Growth Factors

Angiogenesis inhibitor TNP-470, 6-O-(N-chloroacetyl-carbamoyl)-fumagillol, semisynthetic analogue of fumagillin, has strong inhibitory activities against in vivo tumor growth and metastasis in a wide variety of tumors. However, it is still unknown whether this agent inhibits bone metastasis. We examined the effects of TNP-470 in a bone metastasis model in nude mice in which intracardiac injection of the human breast cancer cell line MDA-MB-231 (MDA-231) produced osteolytic bone metastasis. After inoculation of MDA-231 cells into the left heart ventricle, TNP-470 (30 mg/kg, three times a week) or PBS was s.c. administrated for 4 weeks. After this period, the TNP-470 had reduced not only the number and area of osteolytic bone metastases (approximately 60 and 70%, respectively) but also their radiolucency. Histological examination of the femurs of the untreated group revealed that most of the cancellous bone had been replaced by the metastatic cancer. Numerous active osteoclasts were present along the trabecular bone surface surrounded by the metastatic MDA-231 cancer cells aggressively invading the bone marrow. In contrast, in the bone from TNP-470-treated mice, bone destruction was markedly inhibited, and there were much fewer osteoclasts. In a murine bone marrow culture under 1,25-dihydroxyvitamin D3 in which mature functional osteoclasts formed in vitro, TNP-470 significantly inhibited the formation of tartrate-resistant acid phosphatase-positive multinucleated osteoclast-like cells. And also, TNP-470 suppressed the in vivo bone resorption in calvaria treated with interleukin-1beta, an osteoclast stimulator. These data suggested that TNP-470 inhibited bone metastasis through not only antitumor action by its angiogenesis inhibition but also by the inhibition of osteoclastic bone resorption. Our results indicate that TNP-470 should be a potentially beneficial drug to be used in the treatment of osteolytic metastasis.

Topics: Animals; Antibiotics, Antineoplastic; Bone Neoplasms; Bone Resorption; Breast Neoplasms; Cachexia; Calcitriol; Cells, Cultured; Cyclohexanes; Disease Models, Animal; Female; Heart Ventricles; Humans; Injections; Interleukin-1; Mice; Mice, Inbred BALB C; Mice, Nude; Neoplasm Transplantation; Neoplastic Cells, Circulating; Neovascularization, Pathologic; O-(Chloroacetylcarbamoyl)fumagillol; Osteoclasts; Osteolysis; Sesquiterpenes; Tumor Cells, Cultured

To determine the role of telomerase activity in the growth of tumors in rats undergoing chemotherapy, a comparison of the volumes of telomerase-positive transplantable osteosarcomas was made in rats treated with the antineoplastic agent cis-diammine dichloroplatinum (CDDP) or the angiogenesis inhibitor O-(chloroacetylcarbamoyl)fumagillol (AGM-1470). Male F344 rats, 8 weeks old, received transplants of macroscopic lung metastatic nodules into the subcutaneous back space and treatment was started on day 14 thereafter. CDDP was injected i.v. at doses of 0, 0.625, 1.25 and 2.5 mg/kg body weight (b.w.) and AGM-1470 was administered at total doses of 0, 2.5, 5 and 10 mg/kg b.w. over 2 weeks by osmotic pumps, also implanted into the subcutaneous back space, but remote from the transplanted tumors. On day 28, all animals were killed for measurement of transplanted tumor size and determination of telomerase activities by telomeric repeat amplification protocol (TRAP) assay. The results showed telomerase activity to be highly correlated with the treated/non-treated (T/C) tumor size ratio (r = 0.96, P < 0.0001). In a second experiment, CDDP at 2.5 mg/kg b.w. and AGM-1470 at 10 mg/kg b.w., these being the most effective doses, were given as in the first experiment, and animals were serially killed on days 14, 21, 28, 35 and 42. Tumors in rats treated with CDDP and AGM-1470 showed 18.2% and 20.5% of the control telomerase activity on days 35 and 21, respectively, when tumor growth was inhibited. However, on day 42, the activities increased to 46.5% and 92.5%, this correlating with re-growth (r = 0.73, P < 0.0001). These results suggest that decline of telomerase activity may be involved in tumor growth retardation induced by chemotherapeutic agents. This possibility clearly warrants further mechanistic studies.

Topics: Animals; Antibiotics, Antineoplastic; Biomarkers, Tumor; Bone Neoplasms; Cisplatin; Cyclohexanes; Dose-Response Relationship, Drug; Lung Neoplasms; Male; Neoplasm Transplantation; Neovascularization, Pathologic; O-(Chloroacetylcarbamoyl)fumagillol; Osteosarcoma; Rats; Rats, Inbred F344; Regression Analysis; Sesquiterpenes; Telomerase

The efficacy of combination therapy with cis-diammine-dichloroplatinum (II) (CDDP) and o-(chloroacetyl-carbamoyl) fumagillol (AGM-1470) was evaluated experimentally using a transplantable rat osteosarcoma line, previously established in our laboratory, with a high potential for metastasis. Tumor-bearing male Fischer 344 rats were administered CDDP (2.5 mg/kg) together with, or after discontinuation of, AGM-1470 treatment (10 mg/kg/body weight/week). When CDDP was administered three days after discontinuation of AGM-1470 the most pronounced antimetastatic effects were observed, although the antitumor effect was approximately the same.

Topics: Animals; Antibiotics, Antineoplastic; Antineoplastic Agents; Antineoplastic Combined Chemotherapy Protocols; Bone Neoplasms; Cisplatin; Cyclohexanes; Dermatologic Surgical Procedures; Drug Administration Schedule; Injections, Intravenous; Injections, Subcutaneous; Lung Neoplasms; Male; Neoplasm Transplantation; O-(Chloroacetylcarbamoyl)fumagillol; Osteosarcoma; Rats; Rats, Inbred F344; Remission Induction; Sesquiterpenes; Skin Neoplasms; Time Factors

We treated a murine osteosarcoma cell line, LM8, which preferentially metastasizes to the lungs, with a new angiogenesis inhibitor, TNP-470, to evaluate the efficacy of this compound in the suppression of pulmonary metastasis of osteosarcoma. In an in vivo experiment, tumor cells were inoculated i.v. into C3H mice, and TNP-470 or vehicle alone (control group) was administered s.c. every day for 3 weeks. In the TNP-470-treated groups, both the number of pulmonary metastatic nodules and the lung wet weight were significantly reduced in a dose-dependent manner. Similarly, vascular density in the metastatic tumors estimated by immunohistochemical staining with anti-von-Willebrand factor antibody as an endothelial marker were significantly reduced. No severe side-effects were found. In an in vitro experiment, viable tumor cells were counted after 3 days' treatment with TNP-470. The 50% inhibitory concentration was 0.6 ng/ml for LM8, which was more sensitive than other tumor cells previously reported. Our results show that TNP-470 suppresses the pulmonary metastasis of LM8 and suggest that both its anti-angiogenic activity and cytostatic activity towards LM8 are responsible for the antitumor effect.

Topics: Animals; Antibiotics, Antineoplastic; Bone Neoplasms; Cell Division; Cyclohexanes; Lung Neoplasms; Male; Mice; Mice, Inbred C3H; Neoplasm Transplantation; Neovascularization, Pathologic; O-(Chloroacetylcarbamoyl)fumagillol; Osteosarcoma; Sesquiterpenes; Tumor Cells, Cultured