o-(chloroacetylcarbamoyl)fumagillol and Fibrosarcoma

Vasculogenic mimicry (VM) is the formation of a blood supply system that confers aggressive and metastatic properties to tumors and correlates with a poor prognosis in cancer patients. Thus, the inhibition of VM is considered an effective approach for cancer treatment, although such a mechanism remains poorly described. In the present study, we examined methionine aminopeptidase‑2 (MetAP2), a key factor of angiogenesis, and demonstrated that it is pivotal for VM, using pharmacological and genetic approaches. Fumagillin and TNP‑470, angiogenesis inhibitors that target MetAP2, significantly suppressed VM in various human cancer cell lines. We established MetAP2‑knockout (KO) human fibrosarcoma HT1080 cells using the CRISPR/Cas9 system and found that VM was attenuated in these cells. Furthermore, re‑expression of wild‑type MetAP2 restored VM in the MetAP2‑KO HT1080 cells, but the substitution of D251, a conserved amino acid in MetAP2, failed to rescue the VM. Collectively, our results demonstrate that MetAP2 is critical for VM in human cancer cells and suggest fumagillin and TNP‑470 as potent VM‑suppressing agents.

Topics: Aminopeptidases; Angiogenesis Inhibitors; Cell Line, Tumor; CRISPR-Cas Systems; Cyclohexanes; Fatty Acids, Unsaturated; Fibrosarcoma; Gene Knockdown Techniques; Humans; Metalloendopeptidases; Methionyl Aminopeptidases; Neovascularization, Pathologic; O-(Chloroacetylcarbamoyl)fumagillol; Sesquiterpenes

Methionine aminopeptidase (MetAP)-2 has been suggested as a novel target for cancer therapy because the anticancer agent TNP-470 irreversibly inactivates the catalytic activity of this enzyme. However, the importance of MetAP2 in cell growth and tumor progression was uncertain because previous data were based on the chemically reactive TNP-470. Here we show that a rationally designed reversible MetAP2 inhibitor, A-357300, suppresses tumor growth preclinically without the toxicities observed with TNP-470. We have synthesized this bestatin-type MetAP2 inhibitor with the aid of crystal structures of the enzyme-inhibitor complexes and parallel synthesis. A-357300 induces cytostasis by cell cycle arrest at the G(1) phase selectively in endothelial cells and in a subset of tumor cells, but not in most primary cells of nonendothelial type. A-357300 inhibits angiogenesis both in vitro and in vivo and shows potent antitumor efficacy in carcinoma, sarcoma, and neuroblastoma murine models. These data affirm that MetAP2 plays a pivotal role in cell growth and establish that reversible MetAP2 inhibitors are promising novel cancer therapeutic agents.

Topics: Aminopeptidases; Animals; Antineoplastic Agents; Breast Neoplasms; Cell Cycle; Cell Division; Chlorobenzenes; Cornea; Cyclohexanes; Drug Design; Endothelium, Vascular; Female; Fibrosarcoma; Humans; Metalloendopeptidases; Mice; Mice, SCID; Models, Molecular; Neovascularization, Physiologic; Neuroblastoma; O-(Chloroacetylcarbamoyl)fumagillol; Protease Inhibitors; Sesquiterpenes; Xenograft Model Antitumor Assays

We examined whether lymphatic metastasis was inhibited by the potent angiogenesis inhibitor AGM-1470 [O-(chloroacetyl-carbamoyl)fumagillol, TNP-470] using a rat lymphatic metastasis model. Clone A of the rat fibrosarcoma AS653HM, when inoculated into the footpads of syngeneic rats, highly and preferentially metastasized to lymph nodes. In contrast, when AGM-1470 was administered subcutaneously to rats bearing the tumor cells, the tumor growth and incidence of metastasis in the lymph nodes were reduced in a dose- and schedule-dependent manner. Similar inhibition of lymphatic metastasis was also observed in the rats in which treatment with AGM-1470 was initiated following resection of the primary tumor in the foot, indicating that the treatment with AGM-1470 inhibited the progression of lymphatic metastasis at the metastatic sites of the lymph nodes. These results suggest that AGM-1470 can be a potential agent to prevent lymphatic metastasis.

Topics: Animals; Antibiotics, Antineoplastic; Cyclohexanes; Fibrosarcoma; Injections, Subcutaneous; Lymphatic Metastasis; Neoplasm Transplantation; Neovascularization, Pathologic; O-(Chloroacetylcarbamoyl)fumagillol; Rats; Sesquiterpenes; Tumor Cells, Cultured

In cancer patients, dormant micrometastases are often asymptomatic and clinically undetectable, for months or years, until relapse. We have studied dormant lung metastases under angiogenesis suppression in mice. The metastases exhibited rapid growth when the inhibition of angiogenesis was removed. Tumour cell proliferation, as measured by bromodeoxyuridine incorporation and immunohistochemical staining proliferating cell nuclear antigen, was not significantly different in dormant and growing metastases. However, tumour cells of dormant metastases exhibited a more than threefold higher incidence of apoptosis. These data show that metastases remain dormant when tumour cell proliferation is balanced by an equivalent rate of cell death and suggest that angiogenesis inhibitors control metastatic growth by indirectly increasing apoptosis in tumour cells.

Topics: Animals; Antibiotics, Antineoplastic; Apoptosis; Carcinoma, Lewis Lung; Cell Division; Cyclohexanes; Fibrosarcoma; Lung; Lung Neoplasms; Male; Mice; Mice, Inbred C57BL; Neoplasm Metastasis; Neovascularization, Pathologic; O-(Chloroacetylcarbamoyl)fumagillol; Organ Size; Proliferating Cell Nuclear Antigen; S Phase; Sesquiterpenes; Tumor Cells, Cultured

Angiogenesis is a fundamental process by which new blood vessels are formed. Progressive tumor growth necessitates the continuous induction of new capillary blood vessels which converge upon the tumor. Suppression of tumor growth can be accomplished with the use of antiangiogenesis agents. AGM-1470 is a potent angiogenesis inhibitor in vitro and in vivo. In mouse studies, AGM-1470 has suppressed the growth and neovascularization induced by four murine tumors resulting in a 55% to 77% decrease in tumor growth. In these mice significant toxicity did not result from AGM-1470 therapy. AGM-1470 administered systemically to C57BI/6 male mice for 20 to 28 days inhibited the growth of: (1) Lewis lung carcinoma resulting in a T/C (treatment/control = mean tumor volume of treated/mean tumor volume of control) of 0.38 +/- 0.03 (P < .001); (2) colon adenocarcinoma 38 resulting in a T/C of 0.23 +/- 0.02 (P < .001); and (3) fibrosarcoma 105 resulting in a T/C of 0.31 +/- 0.05 (P < .001). To determine if antiangiogenic therapy was equally effective in mice of both sexes and in immunodeficient animals, we tested AGM-1470 in the treatment of fibrosarcoma 105 in both female mice and nude mice. For female mice T/C was 0.24 +/- 0.06 (P < .001). For nude mice T/C was 0.27 +/- 0.06 (P < .001). These results demonstrate that AGM-1470 suppresses the growth of a variety of different tumors. Furthermore, the antitumor effect of AGM-1470 therapy is independent of the immune system and sex.

Topics: Adenocarcinoma; Animals; Antibiotics, Antineoplastic; Body Weight; Colon; Colonic Neoplasms; Cyclohexanes; Female; Fibrosarcoma; Immunocompromised Host; Lung; Lung Neoplasms; Male; Mice; Mice, Nude; Neovascularization, Pathologic; O-(Chloroacetylcarbamoyl)fumagillol; Sesquiterpenes; Sex Factors