Gaku Matsumoto

Expression of Macrophage Migration Inhibitory Factor in Human Breast Cancer: Association with Nodal Spread

Macrophage migration inhibitory factor (MIF) is known to exert pleiotropic functions including inhibition of macrophage migration, anchoring, and counteraction of the anti‐inflammatory and immunosuppressive activity of glucocorticoids. Ninety‐three primary breast cancer tissues and 64 sera of primary breast cancer patients were analyzed for the expression of MIF. The clinico‐pathological significance of MIF expression was evaluated. It was found that MIF was frequently over‐expressed in primary breast cancer tissues. RT‐PCR and western blotting analysis confirmed that wild‐type MIF is expressed, and immunohistochemical analysis showed that MIF expression was localized at tumor cells as well as stromal cells, including tumor‐associated macrophages. Intra‐tumoral MIF protein concentrations detected by enzyme‐linked immunosorbent assay (ELISA) varied with a median value of 1821 ng/mg protein (range: 8–8126 ng/mg protein), and correlated inversely with nodal involvement (P=0.039). No significant correlation was observed with other clinico‐pathological factors including tumor size, menopausal status and hormone receptors. The circulating level of MIF protein ranged up to 105.7 ng/ml (median: 17.3 ng/ml), and it was also found to correlate inversely with the number of involved nodes (P=0.02). A comparative study with other soluble inflammatory mediators showed that intratumoral levels of MIF were significantly associated with those of interleukin‐1β, suggesting that interactions between tumor cells and tumor‐associated macrophages play an important role in the up‐regulation of MIF. The multifunctional inflammatory/immune mediator MIF was frequently expressed in primary breast cancer, and its expression level was inversely associated with nodal spread. Thus, MIF seems to play a role in tumor‐stroma interactions of primary breast cancers, particularly those with a phenotype of node‐negative or minimal nodal spread.

Papillary carcinoma of the extrahepatic bile duct: characteristic features and implications in surgical treatment☆

BACKGROUND Papillary carcinoma of the extrahepatic bile duct presents clinically and histologically distinct features relevant to surgical decision-making. STUDY DESIGN Serial sections of 15 specimens of resected papillary carcinoma of the bile duct were histologically examined to determine mode of spread, possibility of multicentric tumor origins, and coincidence with other neoplastic lesions. The presence of anomalous pancreaticobiliary ductal union was also investigated. These characteristics were considered with regard to surgical treatment. RESULTS Three patients displaying pancreaticobiliary maljunction and one of three patients with a long common channel (> or = 8 mm) exhibited multicentric tumors. Eight patients (53%) demonstrated superficial spread along a mean length of 37.8 mm (range, 5 to 67 mm) of bile duct mucosa. Multicentric tumors developed synchronously in 4 patients, while metachronous tumors were identified in three patients displaying tumor histology similar to the primary lesions. Two of these three underwent successful repeated resection. Concomitant neoplastic lesions in the biliary tract were identified as mucosal dysplasia in four patients and cholangiocellular carcinoma of the liver in two. All tumors but one were removed via hepatic lobectomy or pancreatoduodenectomy, or both, resulting in a 5-year survival rate of 60%. CONCLUSIONS Aggressive resection offers clear survival benefits for patients presenting with tumors displaying extensive superficial spread or multicentric origins. Closer attention should be paid to long common channels in relation to carcinogenesis of the bile duct, in addition to pancreaticobiliary maljunction. The risk of secondary tumor development remains, particularly in patients with pancreaticobiliary maljunction even after excision of the tumor-bearing extrahepatic bile duct.

Resection versus palliation: Treatment of stage III and IVA carcinomas of the pancreas employing intraoperative radiation

Whether advanced pancreatic carcinomas should be surgically removed has been a basic issue because performing an extended resection is futile if it has only a minimum impact on survival. The purpose of this study was to compare the results of pancreatic resection with those of a bypass operation for patients with stage III or IVA pancreatic carcinomas while applying intraoperative radiation therapy (IORT). The therapeutic outcomes of 132 patients who had received IORT for stage III or IVA carcinoma were analyzed retrospectively. The patients were divided into two groups: Group 1 included 68 patients with locally unresectable tumors who underwent a bypass operation; group 2 included 64 patients with resectable tumors who underwent pancreatic resection. Postoperative external beam radiation therapy (EBRT) was also delivered to 90 patients. Multivariate analysis indicated that strong independent predictors of increased survival were EBRT for group 1 (p < 0.0001) and R0 resection for group 2 (p = 0.017). Twenty patients who had been subjected to R0 resection showed the best survival, with a 3-year survival rate of 45%. The survival of group 1 patients receiving EBRT (n = 47) nearly equaled that of group 2 patients undergoing R1 or R2 resection (n = 44) (p = 0.72); but group 1 patients with tumors ≤ 6 cm (n = 31) had a better survival rate than group 2 patients with tumors > 3 cm (n = 28) (p = 0.03). We concluded that postoperative EBRT is essential for improving the survival outcome, even after administering IORT. Patients with stage III lesions undergoing an R0 resection and receiving IORT demonstrated an excellent 3-year survival. A bypass operation plus IORT in combination with EBRT is preferred over IORT used as an adjuvant to R1 or R2 resection.

Effect of Low-Dose Paclitaxel and Docetaxel on Endothelial Progenitor Cells

Objective: Bone marrow (BM)-derived endothelial progenitor cells (EPC) play an important role in neovascularization and tumor growth. It has been reported that docetaxel and paclitaxel inhibit angiogenesis, but the effect of docetaxel and paclitaxel on EPC-induced neovascularization has not been examined. We aimed to clarify the cytotoxic and inhibitory effects of these drugs on EPC. Methods: The effects of drugs on growth, tube formation, and migration of EPC were analyzed in vitro using a rat BM-derived EPC cell line (TR-BME). Fluorescence-labeled TR-BME cells were injected into tumor-bearing rats and accumulation at the tumor site was analyzed by fluorescence-activated cell sorting (FACS). Results: In in vitro cytotoxicity assays of these drugs in TR-BME, rat endothelial cell line TR-BBB and rat tumor cell line Walker 256, the IC50 values for TR-BME were higher than those for TR-BBB or Walker 256. Both drugs inhibited tube formation and migration of TR-BME at lower concentrations than the cytotoxic IC50. In vivo studies showed that a low dose of both drugs inhibited EPC accumulation at the tumor site in tumor-bearing rats, as determined by FACS, and caused a decrease in microvessel density. Conclusion: Docetaxel and paclitaxel directly inhibited EPC-initiated vasculogenesis at low (non-cytotoxic) concentrations, causing suppression of tumor growth.

Mechanical analysis of tumor growth regression by the cyclooxygenase-2 inhibitor, DFU, in a Walker256 rat tumor model: Importance of monocyte chemoattractant protein-1 modulation

Cyclooxygenase (COX)-2 inhibition results in tumor regression; however, little is known about the mechanism. In the present study, using a Walker256 tumor model and a rat bone marrow–derived endothelial cell line TR-BME-2, we analyzed the effects of a new selective COX-2 inhibitor, 5,5-dimethyl-3-(3-fluorophenyl)-4-(4-methylsulphonyl)phenyl-2-(5H)-furanone (DFU), on the production of chemokines and growth factors and on the neovascularization. The oral administration of DFU (5 mg/kg/d) significantly suppressed the tumor growth with decreasing microvessel density in vivo, although it showed no direct inhibition of Walker256 cell proliferation in vitro. It was newly found that the recruitment of systemically injected TR-BME-2 cells into the tumor site was significantly inhibited by DFU treatment. In addition, we found that DFU significantly reduced the production of monocyte chemoattractant protein-1 (MCP-1) both in tumor tissues and in the systemic circulation (P < 0.001 and P < 0.001, respectively). Such reduction was not observed in other chemotactic factors, vascular endothelial growth factor and stromal cell–derived factor-1. The induced chemotaxis of TR-BME-2 by serum of tumor-bearing rats was significantly reduced in DFU-treated rat serum, although DFU showed no direct inhibition for TR-BME-2 cells, either cell growth or chemotaxis. Treatment with neutralizing antibodies to soluble mediators, including MCP-1, significantly suppressed the chemotaxis. Regarding the down-regulation machinery of MCP-1 production in vivo, tumor-associated macrophages seem to play crucial roles, because DFU eliminated MCP-1 production in the activated macrophages remarkably but not in Walker256 tumor cells in vitro. In conclusion, COX-2 inhibitor DFU exerts tumor regression activity in a Walker256 tumor model by suppressing MCP-1 production in tumor tissues and in the circulation.