Takashi Kuwano

Infiltration of COX-2–expressing macrophages is a prerequisite for IL-1β–induced neovascularization and tumor growth

Inflammatory angiogenesis is a critical process in tumor progression and other diseases. The inflammatory cytokine IL-1beta promotes angiogenesis, tumor growth, and metastasis, but its mechanisms remain unclear. We examined the association between IL-1beta-induced angiogenesis and cell inflammation. IL-1beta induced neovascularization in the mouse cornea at rates comparable to those of VEGF. Neutrophil infiltration occurred on day 2. Macrophage infiltration occurred on days 4 and 6. The anti-Gr-1 Ab-induced depletion of infiltrating neutrophils did not affect IL-1beta- or VEGF-induced angiogenesis. The former was reduced in monocyte chemoattractant protein-1-deficient (MCP-1(-/-)) mice compared with wild-type mice. After day 4, clodronate liposomes, which kill macrophages, reduced IL-1beta-induced angiogenesis and partially inhibited VEGF-induced angiogenesis. Infiltrating macrophages near the IL-1beta-induced neovasculature were COX-2 positive. Lewis lung carcinoma cells expressing IL-1beta (LLC/IL-1beta) developed neovasculature with macrophage infiltration and enhanced tumor growth in wild-type but not MCP-1(-/-) mice. A COX-2 inhibitor reduced tumor growth, angiogenesis, and macrophage infiltration in LLC/IL-1beta. Thus, macrophage involvement might be a prerequisite for IL-1beta-induced neovascularization and tumor progression.

Cyclooxygenase 2 is a key enzyme for inflammatory cytokine-induced angiogenesis

Cyclooxygenasel (COX1) and COX2 mediate the rate‐limiting step in arachidonic acid me¬tabolism. Expression of COX2 mRNA and protein is often enhanced in various human cell types by inflam¬matory cytokines such as interleukin‐1β (IL‐1β) and tumor necrosis factor α (TNFα). IL‐1β enhanced ex¬pression of various prostanoids and this expression was blocked by COX2 selective inhibitors. IL‐1β markedly induced angiogenesis in vitro and in vivo, which was significantly inhibited by COX2 selective inhibitors but not by a vascular endothelial growth factor (VEGF) receptor tyrosine kinase inhibitor. In contrast, COX2 selective inhibitors only partially blocked VEGF‐induced angiogenesis. EP2, EP4 (prostaglandin E2 recep¬tors) agonists and thromboxane A2 (TXA2) receptor agonists induced angiogenesis in vitro and in vivo; IL‐1β‐induced angiogenesis was blocked by an EP4 antagonist and a TXA2 receptor antagonist. IL‐1β in¬duced much less angiogenesis in cornea of COX2 knockout mice than that of wild‐type mice. This is the first report that COX2 and some prostanoids play a key role in IL‐1β‐induced angiogenesis.—Kuwano, T., Nakao, S., Yamamoto, H., Tsuneyoshi, M., Yamamoto, T., Kuwano, M., Ono, M. Cyclooxygenase 2 is a keyenzyme for inflammatory cytokine‐induced angiogenesis. FASEB J. 18, 300–310 (2004)

Synergistic Effect of TNF-α in Soluble VCAM-1-Induced Angiogenesis Through α4 Integrins

In our present study we focused on soluble VCAM-1 (sVCAM-1)/α4 integrin-induced angiogenesis and found that this type of angiogenesis was mediated through p38 mitogen-activated protein kinase and focal adhesion kinase (FAK). HUVEC expressed both α4 and β1 integrins, and it was reported that expression of α4 integrin and its counterreceptor, sVCAM-1/VCAM-1, was enhanced in response to an inflammatory cytokine, TNF-α. In endothelial cells phosphorylation of p38 and FAK, but not that of extracellular signal-regulated kinase 1/2 was induced by sVCAM-1. Migration of endothelial cells was stimulated in response to sVCAM-1 at similar levels as those induced by vascular endothelial growth factor, and sVCAM-1-induced migration was almost completely blocked by neutralizing Ab against α4 integrin, by either an inhibitor of p38 (SB203580), or by adenovirus containing FAK-related nonkinase. sVCAM-1 also induced the formation of blood vessels in Matrigel plug assay in vivo, and this neovascularization was blocked by SB203580 or neutralizing Ab against α4 integrin. Moreover, we also confirmed that both TNF-α and sVCAM-1 could synergistically induce angiogenesis in the corneas of mice when each factor at used dose could not induce. This angiogenesis by TNF-α and sVCAM-1 was almost completely blocked by coadministration of SB203580 and also by neutralizing Ab against α4 integrin. These results suggest that sVCAM-1/α4 integrin induces angiogenesis through p38 and FAK signaling pathways.

Bastadin 6, a spongean brominated tyrosine derivative, inhibits tumor angiogenesis by inducing selective apoptosis to endothelial cells.

Bastadin 6, a macrocyclic tetramer of a brominated tyrosine derivative, was isolated from a marine sponge and its anti-angiogenic activity was evaluated. Bastadin 6 was found to inhibit vascular endothelial growth factor (VEGF)- or basic fibroblast growth factor (bFGF)-dependent proliferation (IC50=0.052 μmol/l) of human umbilical vein endothelial cells (HUVECs) 20- to 100-fold selectively in comparison with normal fibroblast (3Y1) or several tumor cells (KB3-1, K562 and Neuro2A). Bastadin 6 also inhibited VEGF- or bFGF-induced tubular formation (0.1 μmol/l, 6 h treatment) and VEGF-induced migration (1 μmol/l, 4 h treatment) of HUVECs. Moreover, bastadin 6 almost completely blocked VEGF- or bFGF-induced in vivo neovascularization in the mice corneal assay and suppressed growth of s.c. inoculated A431 solid tumor in nude mice (100 mg/kg, i.p.). Bastadin 6 induced cell death of HUVECs with an apoptotic phenotype, whereas it showed no effect on the VEGF-induced auto-phosphorylation of VEGF receptors Flt-1 and KDR/Flk-1. These results suggest that the anti-angiogenic effect of bastadin 6 is closely related to selective induction activity of apoptosis against endothelial cells.

New Radiographic Analysis of Sesamoid Rotation in Hallux Valgus: Comparison with Conventional Evaluation Methods

The position of the hallucal sesamoids needs to be included in evaluation of hallux valgus. In order to quantify the rotational position of the hallucal sesamoids, a new weightbearing tangential radiograph was established by means of a specially designed tangential positioning device. This device has a depression, and a tangential radiograph is taken with the metatarsophalangeal joint at 45° dorsiflexion. A lead marker plate is placed on the depression to show the horizontal plane, and the sesamoid rotation angle (SRA) is measured. The SRA is the angle between the tangential line of the most inferior aspect of the medial-lateral sesamoids and the lead marker line. The SRA was compared with values of the four-grade scale and seven-position scale which were measured from the antero-posterior view, with respect to the hallux valgus angle (HVA), by means of conventional methods. Measurements were made of 58 feet in 29 patients with hallux valgus and 64 feet in 32 normal subjects. The SRA showed the highest correlation among the three parameters (r = 0.817). Some cases had a disparity regarding the position of the sesamoids between the tangential view and the AP view due to misclassification on the AP view. We conclude that the scale of position of the sesamoid on the AP view is not valid in some cases, whereas the SRA is useful for assessing quantitatively the rotational position of the hallucal sesamoids in cases of hallux valgus.

Role of squamous cell carcinoma antigen 1 expression in the invasive potential of head and neck squamous cell carcinoma

Serine proteases have important roles in tumor invasion and metastasis, and their inhibitors, serine protease inhibitors (serpins), are attractive targets for therapeutic strategies. On chromosome 18q21, there is a cluster of serpins: maspin, headpin, and squamous cell carcinoma antigen 1 (SCCA1)/SCCA2. Others and we have reported that the expression of these serpins is downregulated in head and neck squamous cell carcinoma (HNSCC) cells compared with normal squamous epithelial cells. In this study, we hypothesized that expression of SCCA1 is biologically disadvantageous to HNSCC cells.

The antitumor effect of a novel angiogenesis inhibitor (an octahydronaphthalene derivative) targeting both VEGF receptor and NF-κB pathway

Development of a novel type of angiogenesis inhibitor will be essential for further improvement of therapeutics against cancer patients. We examined whether an octahydronaphthalene derivative, AMF‐26, which was screened as an inhibitor of intercellular adhesion molecule‐1 (ICAM‐1) production stimulated by inflammatory stimuli in vascular endothelial cells, could block angiogenesis in response to vascular endothelial growth factor (VEGF) and/or inflammatory cytokines. Low dose AMF‐26 effectively inhibited the tumor necrosis factor‐α (TNF‐α)‐ or the interleukin‐1β (IL‐1β)‐induced production of ICAM‐1 in human umbilical vascular endothelial cells (HUVECs). We found that the TNF‐α‐induced phosphorylation of nuclear factor of kappa light polypeptide gene enhancer in B‐cells inhibitor, alpha (IκBα) and nuclear translocation of p65 were impaired by AMF‐26 in both endothelial cells and cancer cells. AMF‐26 was found to inhibit the phosphorylation of VEGF receptor 1 (VEGFR1), VEGFR2 and the downstream signaling molecules Akt, extracellular signal‐regulated kinase (ERK)1/2 stimulated by VEGF in HUVECs. Therefore, the VEGF‐induced proliferation, migration and tube formation of vascular endothelial cells was highly susceptible to inhibition by AMF‐26. Oral administration of AMF‐26 significantly blocked VEGF‐ or IL‐1β‐induced angiogenesis in the mouse cornea, and also tumor angiogenesis and growth. Together, our results indicate that AMF‐26 inhibits angiogenesis through suppression of both VEGFR1/2 and nuclear factor‐κB (NF‐κB) signaling pathways when stimulated by VEGF or inflammatory cytokines. AMF‐26 could be a promising novel candidate drug for cancer treatments.

Radiosynthesis andin vivo evaluation of11C-Iabeled 1,5-diarylpyrazole derivatives for mapping cyclooxygenases

We prepared11C-labeled5-(4-chlorophenyl)-l-(4-methoxyphenyl)-3-(trifluoromethyl)-lH-pyrazole ([11C] 1) and 4-[5-(4-methoxyphenyl)-3-trifluoromethyl-lH-pyrazol-1 -yljbenzenesulfonamide ([11C]2) for imaging COX-1 and COX-2 isoforms, respectively, by positron emission tomography. [11C]l and [11C]2 were synthesized in high radiochemical yields byO-[11C]methylation with [11C]methyl triflate in acetone containing an equivalent of NaOH as a base with respect to the phenolic precursors.In vivo evaluation in rats bearing AH109A hepatoma demonstrated minimal specific binding of [11C]1 to COX-1 in peripheral organs, such as the spleen and small intestine. Carrier-saturable uptake of [11C]2 was found in the spleen, but COX-2-specific binding of [101C]2 was not identifiable in the brain, AH109A hepatoma or other peripheral organs, althoughex vivo autoradiography showed regionally different distribution in the brain and AH 109A. The results suggest that neither [11C]1 nor [11C]2 is a suitable radioligand forin vivo biomarkers of COX enzymes, mainly because of marked non-specific binding.