Hirokuni Yoshimura

Host Prostaglandin E2-EP3 Signaling Regulates Tumor-Associated Angiogenesis and Tumor Growth

Nonsteroidal antiinflammatories are known to suppress incidence and progression of malignancies including colorectal cancers. However, the precise mechanism of this action remains unknown. Using prostaglandin (PG) receptor knockout mice, we have evaluated a role of PGs in tumor-associated angiogenesis and tumor growth, and identified PG receptors involved. Sarcoma-180 cells implanted in wild-type (WT) mice formed a tumor with extensive angiogenesis, which was greatly suppressed by specific inhibitors for cyclooxygenase (COX)-2 but not for COX-1. Angiogenesis in sponge implantation model, which can mimic tumor-stromal angiogenesis, was markedly suppressed in mice lacking EP3 (EP3−/−) with reduced expression of vascular endothelial growth factor (VEGF) around the sponge implants. Further, implanted tumor growth (sarcoma-180, Lewis lung carcinoma) was markedly suppressed in EP3−/−, in which tumor-associated angiogenesis was also reduced. Immunohistochemical analysis revealed that major VEGF-expressing cells in the stroma were CD3/Mac-1 double-negative fibroblasts, and that VEGF-expression in the stroma was markedly reduced in EP3−/−, compared with WT. Application of an EP3 receptor antagonist inhibited tumor growth and angiogenesis in WT, but not in EP3−/−. These results demonstrate significance of host stromal PGE2-EP3 receptor signaling in tumor development and angiogenesis. An EP3 receptor antagonist may be a candidate of chemopreventive agents effective for malignant tumors.

COX-2/VEGF-dependent facilitation of tumor-associated angiogenesis and tumor growth in vivo.

Nonsteroidal anti-inflammatory drugs are known to suppress the occurrence and progression of malignancies such as colorectal cancers. However, the precise mechanism of these actions remains unknown. We have evaluated the role of an inducible cyclo-oxygenase (COX-2) in tumor-associated angiogenesis and tumor growth, and identified the downstream molecules involved using a ddy mouse model of sponge angiogenesis, which mimics tumor angiogenesis and is COX-2 and vascular endothelial growth factor (VEGF) dependent. In this model, VEGF expression was down-regulated by selective COX-2 inhibition with NS-398. To find out the involvement of COX-2/VEGF pathway in tumor-associated angiogenesis, we estimated angiogenesis occurring around implanted Millipore chambers containing sarcoma-180 (S-180) cells or Lewis lung carcinoma cells. Daily oral administration of NS-398 or of aspirin, a nonselective COX inhibitor, suppressed angiogenesis seen around the Millipore chambers. S-180 cells implanted in ddy mice formed substantial tumors with extensive angiogenesis markedly suppressed by aspirin and COX-2 inhibitors NS-398 and JTE522, but not by mofezolac, an inhibitor of constitutive COX-1. Tumor-associated angiogenesis was also significantly suppressed by a neutralizing antibody against VEGF. S-180 tumor growth in the subcutaneous tissues was also suppressed by aspirin, COX-2 selective inhibitors, and the VEGF antibody, but not by the COX-1 inhibitor. These results demonstrate that the inhibition of the COX-2/VEGF-dependent pathway was effective in tumor-associated angiogenesis, tumor growth, and tumor metastasis.

Pulmonary adenocarcinoma with heterotopic bone formation

Adenocarcinoma of the lung is a common malignancy. Frequently, this tumor can cause calcification within a primary tumor. However, an extremely rare occurrence in lung carcinomas is ossification within a primary tumor, and to our knowledge only three cases have been reported. We report a case of pulmonary adenocarcinoma with ossification, and discuss the pathogenesis of intratumoral ossification with a review of the literature.

Cyclooxygenase-2 and adenylate cyclase/protein kinase A signaling pathway enhances angiogenesis through induction of vascular endothelial growth factor in rat sponge implants.

Angiogenesis is reportedly enhanced by prostaglandins (PGs). In the present experiment, we tested whether or not COX-2 and adenylate cyclase/protein kinase A (AC/PKA)-dependent VEGF induction enhanced angiogenesis in this model. Angiogenesis was enhanced by topical injection of human recombinant basic fibroblast growth factor (bFGF). The enhanced angiogenesis by bFGF was inhibited by indomethacin or selective COX-2 inhibitors, NS398, nimesulide, and JTE-522. Topical daily injections of 8-bromo-cAMP enhanced angiogenesis in a dose-dependent manner. Forskolin. an activator of AC, also facilitated angiogenesis in a dose-dependent manner, as did amrinone, an inhibitor of phosphodiesterase. VEGF induction was confirmed by the increased levels in the fluids in the sponge matrix after topical injection of 8-bromo-CAMP. Immunohistochemical investigation further revealed the VEGF-expressed cells in the sponge granulation tissues to be fibroblasts, and the intensity of positive reactions was enhanced by bFGF, 8-bromo-cAMP. forskolin, and amrinone. Angiogenesis was inhibited by indometacin or selective COX-2 inhibitors, NS-398, nimesulide, and JTE-522. In addition, angiogenesis without topical injections of the above compounds was also suppressed by SQ22,536, an inhibitor for AC, or H-89, an inhibitor for PKA, with concomitant reductions in VEGF levels. Daily topical injections of neutralizing antibody or anti-sense oligonucleotide against VEGF significantly suppressed angiogenesis. These results suggested that COX-2 and AC/PKA-dependent induction of VEGF certainly enhanced angiogenesis, and that pharmacological tools for controlling this signaling pathway may be able to facilitate the management of conditions involving angiogenesis.

The role of kinin B1 in the plasma extravasation of carrageenin-induced pleurisy.

The role of des-Arg9-bradykinin (des-Arg9-BK) and kinin B1 receptor in the plasma extravasation of rat carrageenin-induced pleurisy was investigated employing B1 receptor agonist and antagonists and kininogen-deficient rats. Expression of the B1 receptor mRNA in pleura was induced from 3 to 5 h after the injection of carrageenin into the pleural cavity of Sprague-Dawley rats. Exogenous injection of des-Arg9-BK into the pleural cavity provoked a significant increase in plasma extravasation in 5 h carrageenin-induced pleurisy, but not in 20 min kaolin-induced pleurisy. The level of immunoreactive des-Arg9-BK in the exudate of 5 h carrageenin-induced pleurisy was higher than that of bradykinin (BK). Administration of the B1 receptor antagonists, des-Arg9-[Leu8]-BK or des-Arg9-D-Arg-[Hyp3, Thi5, D-Tic7,Oic8]-BK significantly reduced the exudation rate. However, intrapleural administration of des-Arg9-BK to plasma kininogen-deficient. Brown Norway-Katholiek rats did not result in a further increase in the plasma extravasation. In conclusion, endogenously generated des-Arg9-BK could contribute to the plasma extravasation in carrageenin-induced pleurisy via mediation of the inducible B1 receptor.

Prognostic impact of nestin expression in resected large cell neuroendocrine carcinoma of the lung

BACKGROUND Large cell neuroendocrine carcinoma (LCNEC) of the lung is categorized as a high-grade neuroendocrine carcinoma with an aggressive clinical behavior. Nestin is a class VI intermediate filament protein expressed in stem/progenitor cells during central nervous system development. Recently, we reported that nestin expression is a prognostic indicator of a poorer survival probability in patients with resected NSCLC. In the present study, we aimed to determine its prognostic significance concerning survival in patients with resected LCNEC. MATERIALS AND METHODS Nestin expression in tumor cells was immunohistochemically studied in 30 patients with resected LCNEC, and its associations with clinicopathologic parameters including the Ki-67 labeling index (LI) and TTF-1 expression were evaluated. Kaplan-Meier survival analysis and Cox proportional hazards models were used to estimate the effect of nestin expression on survival. RESULTS Nestin expression was observed in 8 of the 30 (26.7%) LCNECs. Clinicopathologically, although no significant association between nestin expression and age, gender, smoking habits, p-TNM stage, tumor size, nodal status, or TTF-1 expression was observed, nestin expression was significantly associated with a high Ki-67 LI (P=0.012). On survival analysis, nestin expression was significantly associated with a poorer prognosis in patients with LCNEC (P=0.016). The Cox proportional regression model confirmed that the crude hazard ratio (95%CI) of nestin expression was 3.40 (1.18-9.77). CONCLUSIONS The present study suggests that nestin expression seems to be a prognostic indicator of a poorer survival probability in patients with resected LCNEC, although its prognostic significance still requires confirmation with larger patient populations.

Double-patch closure using gelatin resorcine formol glue of a ventricular septal perforation following acute myocardial infarction.

Complete closure is most important when attempting acute-phase closure of a ventricular septal perforation following acute myocardial infarction. Here, we present a case of a 76-year-old male with a ventricular septal perforation following acute myocardial infarction. The ventricular septal perforation was repaired by stitching small and large bovine pericardial patches onto the affected septum from the side of the left ventricle, then cementing the two patches together with gelatin resorcine formol glue injected into the space between them. Complete closure of the ventricular septal perforation was accomplished. Simultaneously, right coronary artery bypass grafting was performed using a saphenous vein. The postoperative course was uneventful, and the patient was discharged, with a favorable post-discharge course for 24 months to date after surgery.

Arch reconstruction without circulatory arrest in neonates.

Between May 2000 and December 2002, 10 neonates underwent arch reconstruction without circulatory arrest. Age at surgery ranged from 1 to 18 days, and body weight ranged from 1.62 to 3.38 kg. The diagnosis was interrupted aortic arch in 4, hypoplastic left heart syndrome in 3, and coarctation complex in 3. A 3 mm polytetrafluoroethylene graft was anastomosed to the innominate artery, and the brain was perfused via this graft while the aortic arch was reconstructed. Regional cerebral oxygen saturation and the right and left radial artery pressures were monitored. There were 2 deaths: one because of low cardiac output syndrome after a Norwood operation; another from multiple organ failure due to preoperatively undetected congenital biliary atresia. Regional cerebral oxygen saturation was kept constant at over 40% during regional cerebral perfusion. There were no neurologic sequelae observed postoperatively. It was concluded that the regional cerebral perfusion technique can be safely applied during neonatal aortic arch reconstruction, and deep hypothermic circulatory arrest should be avoided.

Ulnar artery graft for myocardial revascularization.

We present a 60-year-old man who underwent coronary artery bypass grafting using an ulnar artery as one of the grafts intended to release angina pectoris. Previously, his right leg had been amputated following a traffic accident. The blood supply of his left leg was reduced due to atherosclerotic stenotic change (left ankle pressure index 0.6). He had been under treatment for severe diabetes mellitus for 4 years. Coronary angiography revealed severe stenosis in the triple coronary artery system. Immediate myocardial revascularization was considered necessary. We considered that saphenous vein grafts and bilateral internal thoracic artery grafts were unsuitable for this patient. Moreover, Allens test was positive in the bilateral forearms. Coronary artery bypass surgery consisted of left internal thoracic artery grafting to the left anterior descending artery, right gastroepiploic artery grafting to the right coronary artery, and left ulnar artery grafting to the diagonal branch. No myocardial or hand complications were observed after surgery. Following a review of the Japanese literature, we conclude that our case is the first report of an ulnar artery graft for coronary artery bypass grafting in Japan.

Pulmonary Artery Sling Associated with Tetralogy of Fallot

We describe a rare case of pulmonary artery sling occurring simultaneously with tetralogy of Fallot. This report describes the successful concomitant repair of both intracardiac anomalies.