Cyclooxygenase (COX)-2 is known to correlate with poor cancer prognosis and to contribute to tumor metastasis. However, the precise mechanism of this phenomenon remains unknown. We have previously reported that host stromal prostaglandin E 2 (PGE 2 )-prostaglandin E2 receptor (EP)3 signaling appears critical for tumor-associated angiogenesis and tumor growth. Here we tested whether the EP3 receptor has a critical role in tumor metastasis. Lewis lung carcinoma (LLC) cells were intravenously injected into WT mice and mice treated with the COX-2 inhibitor NS-398. The nonselective COX inhibitor aspirin reduced lung metastasis, but the COX-1 inhibitor SC560 did not. The expression of matrix metalloproteinases (MMP)-9 and vascular endothelial growth factor (VEGF)-A was suppressed in NS-398-treated mice compared with PBS-treated mice. Lungs containing LLC colonies were markedly reduced in EP3 receptor knockout (EP3 )/) ) mice compared with WT mice. The expression of MMP-9 and VEGF-A was downregulated in metastatic lungs of EP3 )/) mice. An immunohistochemical study revealed that MMP-9-expressing endothelial cells were markedly reduced in EP3 )/) mice compared with WT mice. When HUVEC were treated with agonists for EP1, EP2, EP3, or EP4, only the EP3 agonist enhanced MMP-9 expression. These results suggested that EP3 receptor signaling on endothelial cells is essential for the MMP-9 upregulation that enhances tumor metastasis and angiogenesis. An EP3 receptor antagonist may be useful to protect against tumor metastasis. (Cancer Sci 2009; 100: 2318-2324 M etastasis is the primary cause of mortality in cancer patients.(1) While it has been recognized that the movement of neoplastic cells is not a random process, the molecular and cellular mechanisms governing their movement, survival through foreign tissue, and parameters for selection of their final destination remain unclear. To produce clinically relevant lesions, metastatic cells must complete the following steps, involving: the ability of tumor cells to escape from their original position, to attach to the extracellular matrix (ECM), to degrade the ECM component, and to migrate through these ECM. Thus, both cell-cell adhesion and ECM degradation represent significant barriers to the metastasis of tumor cells. Nonsteroidal anti-inflammatory drugs (NSAID), which block the enzyme activity of cyclooxygenase (COX), have been widely used for anti-inflammatory and analgesic purposes. Several papers have reported that a significant reduction in mortality from colorectal cancer occurred depending on the cumulative doses of an NSAID, but on the other hand further evidence suggests that NSAID also affect the incidence and progression of other types of cancer, pointing to a possible role of COX in other types of tumor formation. (3)(4)(5) Prostaglandins comprise a large family of small lipid molecules derived from COX-1-and COX-2-mediated metabolism of arachidonic acid to prostaglandin G 2 (PGG 2 ) ⁄ prostaglandin H 2 (H 2 ).(6) Cell-specific prostaglandin synthases convert pros...

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E-type prostaglandins have been reported to be proangiogenic in vivo. Thus, we examined prostaglandin receptor signaling relevant to wound-induced angiogenesis. Full-thickness skin wounds were created on the backs of mice, and angiogenesis in wound granulation tissues was estimated. Wound closure and re-epithelization in EP3 receptor knockout mice (EP3 ؊/؊ ) were significantly delayed compared with their wild-type (WT) mice, whereas those in EP1 ؊/؊ , EP2 ؊/؊ , and EP4 ؊/؊ were not delayed. Wound-induced angiogenesis estimated with CD31 immunohistochemistry in EP3 ؊/؊ mice was significantly inhibited compared with that in WT mice. Immunoreactive vascular endothelial growth factor (VEGF) in wound granulation tissues in EP3 ؊/؊ mice was markedly less than that in WT mice. Wound closure in WT mice was delayed significantly by VEGF neutralizing antibody compared with control IgG. Wound-induced angiogenesis and wound closure were significantly suppressed in EP3 ؊/؊ bone marrow transplantation mice compared with those in WT bone marrow transplantation mice. These were accompanied with the reductions in accumulation of VEGF-expressing cells in wound granulation tissues and in mobilization of VEGF receptor 1-expressing leukocytes in peripheral circulation. These results indicate that the recruitment of EP3-expressing cells to wound granulation tissues is critical for surgical wound healing and angiogenesis via up-regulation of VEGF. (Am J Pathol

The characteristics of adult patients with chronic active Epstein-Barr virus infection are poorly recognized, hindering early diagnosis and an improved prognosis. We studied 54 patients with adult-onset chronic active Epstein-Barr virus infection diagnosed between 2005 and 2015. Adult onset was defined as an estimated age of onset of 15 years or older. To characterize the clinical features of these adults, we compared them to those of 75 pediatric cases (estimated age of onset <15 years). We compared the prognosis of adult-onset chronic active Epstein-Barr virus infection with that of patients with nasal-type (n=37) and non-nasal-type (n=45) extranodal NK/T-cell lymphoma. The median estimated age of onset of these lymphomas was 39 years (range, 16–86 years). Compared to patients with pediatric-onset disease, those in whom the chronic active Epstein-Barr virus infection developed in adulthood had a significantly decreased incidence of fever (P=0.005), but greater frequency of skin lesions (P<0.001). Moreover, hypersensitivity to mosquito bites and the occurrence of hydroa vacciniforme were less frequent in patients with adult-onset disease (P<0.001 and P=0.0238, respectively). Thrombocytopenia, high Epstein-Barr virus nuclear antigen antibody titer, and the presence of hemophagocytic syndrome were associated with a poor prognosis (P=0.0087, P=0.0236, and P=0.0149, respectively). Allogeneic hematopoietic stem cell transplantation may improve survival (P=0.0289). Compared to pediatric-onset chronic active Epstein-Barr virus infection and extranodal NK/T-cell lymphoma, adult-onset chronic active Epstein-Barr virus infection had a poorer prognosis (P<0.001 and P=0.0484, respectively). Chronic active Epstein-Barr virus infection can develop in a wide age range, with clinical differences between adult-onset and pediatric-onset disease. Adult-onset chronic active Epstein-Barr virus infection is a disease with a poor prognosis. Further research will be needed.