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One of the major factors for successful DCs immunotherapy is thought to be the maintenance of the migratory activity of matured DCs. We evaluated the effectiveness of PSK on OK432-activated DCs, in terms of maturation, migration and induction of CTLs. When DCs were treated with both OK432 and PSK, migration ability of the DCs were significantly high as compared to OK432 alone preserving the beneficial effect of OK432 treatment. BRM cocktail treatment with OK432 and PSK induced high level of migration activity in activated DCs, suggesting a potential protocol for more effective DCs immunotherapy for cancer.

Background. To determine the significance of bone marrow disseminated tumor cells in gastric cancer, we investigated the mRNA expression levels of carcinoembryonic antigen (CEA), cytokeratin 19 (CK19), and cytokeratin 20 (CK20) using the real-time quantitative reverse-transcription polymerase chain reaction (RQ-PCR). Methods. Bone marrow samples were aspirated from the sternum at the time of surgery in 65 patients with resectable gastric cancer. Total RNA was extracted from bone marrow; and the expression levels of CEA, CK19, and CK20 mRNA were determined by RQ-PCR using an ABI PRISM 7000 and quantified against the GAPDH mRNA level. Results. The detection limits of these genes were determined in the gastric cancer cell line MKN-45 and the colon cancer cell line C-1, which had been serially diluted in peripheral blood mononuclear cells (PBMCs). A rate of 1 cancer cell/ million PBMCs was obtained by detecting CEA and CK19 mRNA in MKN-45 and by detecting CK20 mRNA in C-1. In the clinical samples, only 1 of the 65 gastric cancer patients (1.5%) who had stage IV disease was positive for CEA, CK19, and CK20 mRNA; none of CEA, CK19, or CK20 mRNA was positive in the remaining 64 patients. No significant correlation was observed between disseminated cancer cells in bone marrow and clinicopathological features, including simultaneous or metachronous hepatic metastasis and patient survival. Conclusion. The incidence of disseminated cancer cells in bone marrow in our study appears low, unlike that in previous reports. The significance of disseminated cancer cells in bone marrow may also be quite low in gastric cancer.

Dendritic cells (DCs) are potent antigen-presenting cells that are central to the regulation, maturation, and maintenance of the cellular immune response against cancer. In contrast, CD4(+)CD25(+) regulatory T cells (Tregs) play a central role in self-tolerance and suppress antitumor immunity. In this study, we investigated the clinical significance of mature CD83(+) DCs and Foxp3(+) Tregs in the primary tumor and regional lymph nodes from the viewpoint of the two opposing players in the immune responses.We investigated, immunohistochemically, the density of CD83(+) DCs and Foxp3(+) Tregs in primary lesions of gastric cancer (n = 123), as well as in regional lymph nodes with (n = 40) or without metastasis (n = 40).Decreased density of CD83(+) DCs and increased density of Foxp3(+) Tregs were observed in the primary tumor and metastatic lymph nodes. Density was significantly correlated with certain clinicopathological features. Poor prognosis was observed in patients with a low density of CD83(+) DCs and a high density of Foxp3(+) Tregs in primary lesions. For patients with metastatic lymph nodes, the density of CD83(+) DCs in negative lymph nodes was found to be an independent prognostic factor by multivariate analysis.The density of CD83(+) DCs and Foxp3(+) Tregs was inversely correlated with tumor progression and reflected the prognosis of gastric cancer.

Claudin, occludin, and zonula occludens (ZO)-1 are known as tight-junction-associated proteins. The aim of this study was to examine the expression of these proteins in gastric carcinoma. Gastric cancer tissues (n = 124) were obtained from 124 patients who underwent gastrectomy at our hospital between January 2000 and December 2004. The expression of the above tight-junction-associated proteins in carcinoma, normal mucosa, and metaplastic epithelium was examined using immunohistochemistry. In addition, the expression of claudin-4 mRNA was examined in fresh frozen tissue obtained from 34 patients. Significant correlations were seen between the expression of claudin-4, occludin, and ZO-1. In regard to claudin-4, significant correlations were seen between the expression of claudin-4 evaluated by immunohistochemistry and the expression of claudin-4 mRNA. Claudin-4 expression was significantly decreased in tumors with undifferentiated-type adenocarcinoma, advanced T stage, lymph node metastasis, and peritoneal metastasis. Occludin and ZO-1 expression was significantly decreased in tumors with undifferentiated-type adenocarcinoma. Overall survival was significantly shorter in patients with low claudin-4 expression. Cox multivariate analysis revealed that low claudin-4 expression was independently associated with significantly decreased overall survival. Tight-junction-associated proteins, particularly claudin-4, may play important roles in determining invasiveness, metastatic potential, and survival in gastric cancer.

15000 Background: A tight junction is one of components of intercellular junctional complexes and play an important role in maintaining barrier function and cellular porlarity. Claudin, occluding, and ZO-1 are known as trans-membrane proteins which compose tight junction. Roles of these tight junction-associated proteins of gastric cancer is not yet determined. In this study, we investigated expression levels of these proteins in gastric cancer immunohistochemically and compared the results with clinicopathological features of the tumors and patient prognosis. Methods: One hundred and twenty-four gastric cancer patients underwent gastrectomy between 2000 and 2004 were included in this study. Formalin fixed and parafine embedded tissues were sliced into 4-μm sections and immunohistchemistry was performed using anti-claudin-4, anti-occluding and anti-ZO-1 antibodies. Stained slides were investigated and the incidence of positive cells was graded as: 0, negative; 1, < 20 %; 2, 20–80 %; 3, >80 %. Results: The expression of claudin-4, occludin, and ZO-1 was observed at the membrane, and the positivity rates in cancer tissues were 87.1%, 95.2% and 100%, respectively. In concerning with correlation between protein expression and clinicopathologic features, claudin-4 expression was significantly decreased in tumors with undifferentiated type adenocarcinoma (p No significant financial relationships to disclose.

13034 Background: We have previously reported that tumors with high orotate phosphoribosil transferase (OPRT) and low dihydropyrimidine dehydrogenase (DPD) mRNA expression levels showed remarkable sensitivity to 5-fluorouracil (5-FU) by real-time RT-PCR using fresh frozen (FF) tumor samples. However, the use of fresh frozen samples has some limitations. The use of formalin fixed parafine embedded (FFPE) samples has great advantage to apply these technologies for clinical settings. In order to investigate the feasibility of real-time RT-PCR from FFPE samples to predict sensitivitiy to 5-fluorouracil (5-FU), we investigated the gene expression levels of 5-FU metabolism-relating enzymes by real-time RT-PCR from FFPE samples and compared the results from FF samples in gastric and colorectal cancer. Methods: FFPE samples and FF samples were obtained from 46 patients with gastric cancer and 29 patients with colorectal cancer. Gene expression levels of tymidylate synthase (TS), OPRT, thymidine phosphorylase (TP) and DPD were determined by quantitative real-time RT-PCR. In FFPE samples tumor tissue was obtained using laser captured microdissection (LCM). Tumor sensitivity to 5-FU was evaluated by in vitro ATP assay. Results: Gene expression levels of TS, TP, DPD determined from FFPE samples significantly correlated with those from FF samples. Although respective gene expression levels alone failed to show signifcianct correlation with the in vitro 5-FU sensitivity, statistically significant correlation was noted either from the samples of FF or FFPE in both gastric (FF: r = 0.660, FFPE: r = 0.780) and colorectal cancer (FF: r = 0.780, FFPE: r = 0.660), when OPRT/DPD mRNA ratio was applied for comparison with the results of 5-FU sensitivity. Thus, high OPRT/DPD ratio determined from FFPE samples resulted in high sensitivity to 5-FU. Conclusions: From these results, it is suggested that sensitivity to 5-FU is predictable by quantitative RT-PCR using FFPE samples. Measurement of 5-FU metabolism-relating enzyme gene expression level from FFPE samples appeared to be feasible for predicting 5-FU sensitivity and to have great advantage to apply the molecular predicting assay in clinical settings. [Table: see text]

4143 Background: Five-fluorouracil (5-FU) is still one of the key-drug for chemotherapy in gastric and colorectal cancer. Therefore, prediction of 5-FU sensitivity is of great importance for chemot...

4200 Background: We had previously reported that peritoneal micrometastasis determined by CEA mRNA level in peritoneal washings using real-time quantitative RT-PCR (RQ-PCR) is a good predictor for ...