Teiji Naka

Tumor-infiltrating CD4+ Th17 cells produce IL-17 in tumor microenvironment and promote tumor progression in human gastric cancer

Recently, a subset of IL-17 producing T cells distinct from Th1 or Th2 cells has been described as key players in inflammation and autoimmune diseases as well as cancer development. In this study, we investigated the expression level of IL-17 and T helper 17 (Th17)-related cytokines in gastric cancer tissues and assessed the association of their expression with angiogenesis and their clinicopathological parameters. Tumor and adjacent normal tissues were obtained from 82 patients with gastric cancer. IL-17, IL-21 and IL-23 mRNA expression levels were quantified by real-time RT-PCR. Th17 infiltration, microvessel density and neutrophil infiltration in tumor tissues were examined by immunohistochemistry and double immunofluorescence histochemistry. Expression of IL-17, IL-21 and IL-23 mRNA was found to be significantly up-regulated in tumor tissues compared with adjacent normal tissues. The expression level of IL-17 mRNA strongly and positively correlated with that of IL-21 mRNA in tumor tissue. The number of vascular endothelial cells and infiltrating neutrophils was significantly larger in tumors expressing a high level of IL-17 mRNA than in tumors expressing a low level of IL-17 mRNA. In tumor tissues most CD4+ cells were stained with anti-IL-17 antibody. The expression level of IL-17 mRNA in gastric tumors was associated with the depth of the tumors, lymph-vascular invasion and lymph node involvement, suggesting that IL-17 obviously was related to tumor progression. IL-17 and IL-21, which regulates IL-17, would be potential therapeutic targets for the treatment of gastric cancer.

Surgical management of small gastrointestinal stromal tumors of the stomach.

Small gastrointestinal stromal tumors (GISTs) (<3 cm) occasionally are found in the stomach during endoscopy. There is no consensus about the surgical management of these small tumors, although this clinical issue is crucial because some of the tumors show unexpected malignant behavior. In this study, we evaluated the clinical management of patients with gastric GISTs who underwent surgical resection. Altogether, 31 patients with gastric GISTs were examined retrospectively. Surgical resection was fundamentally indicated for the patients with gastric GISTs suspected to be malignant by endoscopy or endoscopic ultrasonography (EUS). The malignant grade of the GISTs was evaluated by the mitotic rate, tumor size, and MIB-1 index. EUS was useful for differentiating benign from malignant GISTs; but by limiting the study to patients with small tumors (<3 cm), the diagnostic value of EUS was not satisfactory for defining the surgical indication. Tumors that were <50 mm were successfully treated by laparoscopic surgery. Of the 31 patients, 4 had a relapse of the disease, and 1 of those 4 patients had a small tumor (30 mm). All of the recurrences were classified in the high risk category. Surgery is indicated for gastric GISTs that are ≥20 mm or are suspected to be malignant based on EUS findings. Laparoscopic resection is feasible and is recommended as the treatment of choice for patients with tumors < 50 mm. Risk assessment can be most useful for predicting recurrence.

Influence of Overweight on Patients With Gastric Cancer After Undergoing Curative Gastrectomy An Analysis of 689 Consecutive Cases Managed by a Single Center

HYPOTHESIS Overweight (body mass index [calculated as weight in kilograms divided by height in meters squared], > or =25.0) has an effect on surgical results, postoperative complications, and long-term survival in patients with gastric cancer who underwent curative gastrectomy. DESIGN Retrospective study from January 1, 1992, through December 31, 2002. SETTING Wakayama Medical University Hospital. PATIENTS This study included 689 patients who underwent curative gastrectomy (R0). Patients who underwent laparoscopic gastrectomy, gastrectomy with pancreaticoduodenectomy, gastrectomy with another organ resection (liver, colon, or ovary), or gastrectomy with thoracotomy were not included. MAIN OUTCOME MEASURES Duration of operation, amount of blood loss, incidence of postoperative complications, and survival analysis. RESULTS The mean (SD) duration of the operation was longer in the overweight group (315 [75] minutes) than in the normal-weight group (277 [85] minutes) (P < .001). The mean (SD) intraoperative blood loss was larger in the overweight group (882 [764] mL) than in the normal-weight group (536 [410] mL) (P < .001). The rates of postoperative complications (anastomotic leakage, pancreatic fistula, and intra-abdominal abscess) were significantly higher in the overweight group (P < .05). Multivariate logistic regression analysis identified that postoperative complications were significantly associated with being overweight (P = .01) and with undergoing pancreatectomy (P = .03). Disease-specific and overall survival did not show any significant difference between the 2 groups. CONCLUSIONS Being overweight is not a poor risk factor for survival in patients with gastric cancer, although it is independently predictive of postoperative complications.

Analysis of the prognostic factors and evaluation of surgical treatment for synchronous liver metastases from gastric cancer.

Background and aimsWhether or not a synchronous resection of liver metastases from gastric cancer provides a survival benefit has been a key issue. We identify the significant prognostic factors and clarify the beneficial effect on the survival of liver surgical treatment.Materials and methodsWe reviewed 72 patients who underwent a gastrectomy for gastric cancer with synchronous liver metastases and classified the liver metastases into three grades, such as H1: metastases were limited to one of the lobes, H2: there were a few scattered metastases in both lobes, and H3: there were numerous scattered metastases.ResultsH1, 2 metastases, and an absence of peritoneal dissemination (P0) were significantly independent prognostic factors for liver metastases of gastric cancer. In addition, the cumulative 1 and 5-year survival rates of liver surgical treatment (hepatic resection and/or microwave coagulation therapy) were 80.0% and 60.0%, whereas the survival rates for non-hepatic surgical treatment were 36.4% and 0% in 26 patients with H1, 2, and P0. In those patients, the radical operation, the solitary metastatic liver tumor, and no-distant lymph node metastases were independent prognostic determinants of survival.ConclusionThe radical operation including the surgical treatment for metastatic liver tumors should be performed to improve the prognosis in gastric cancer patients with synchronous H1, 2, and P0.

Dendritic Cells Transduced with Tumor-Associated Antigen Gene Elicit Potent Therapeutic Antitumor Immunity: Comparison with Immunodominant Peptide-Pulsed DCs

Several studies have shown that vaccine therapy using dendritic cells (DCs) pulsed with specific tumor antigen peptides can effectively induce antitumor immunity. Peptide-pulsed DC therapy is reported to be effective against melanoma, while it is still not sufficient to show the antitumor therapeutic effect against epithelial solid tumors such as gastrointestinal malignancies. Recently, it has been reported that vaccine therapy using DCs transduced with a surrogate tumor antigen gene can elicit a potent therapeutic antitumor immunity. In this study, we investigated the efficacy of vaccine therapy using DCs transduced with the natural tumor antigen in comparison with peptide-pulsed DCs. DCs derived from murine bone marrow were adenovirally transduced with murine endogenous tumor antigen gp70 gene, which is expressed in CT26 cells, or DCs were pulsed with the immunodominant peptide AH-1 derived from gp70. We compared these two cancer vaccines in terms of induction of antigen-specific cytotoxic T lymphocyte (CTL) responses, CD4+ T cell response against tumor cells, migratory capacity of DCs and therapeutic immunity in vivo. The cytotoxic activity of splenocytes against CT26 and Meth-A pulsed with AH-1 in mice immunized with gp70 gene-transduced DCs was higher than that with AH-1-pulsed DCs. CD4+ T cells induced from mice immunized with gp70 gene-transduced DCs produced higher levels of IFN-γ by stimulation with CT26 than those from mice immunized with AH-1-pulsed DCs (p < 0.0001), and it was suggested that DCs transduced with tumor-associated antigen (TAA) gene induced tumor-specific CD4+ T cells, and those CD4+ T cells played a critical role in the priming phase of the CD8+ T cell response for the induction of CD8+ CTL. Furthermore, DCs adenovirally transduced with TAA gene showed an enhancement of expression of CC chemokine receptor 7 and improved the migratory capacity to draining lymph nodes. In subcutaneous models, the vaccination using gp70 gene-transduced DCs provided a remarkably higher therapeutic efficacy than that using AH-1-pulsed DCs. These results suggested that vaccine therapy using DCs adenovirally transduced with TAA gene can elicit potent antitumor immunity, and may be useful for clinical application.

Successful cancer vaccine therapy for carcinoembryonic antigen (CEA)-expressing colon cancer using genetically modified dendritic cells that express CEA and T helper-type 1 cytokines in CEA transgenic mice

This study was designed to determine whether the vaccination of genetically modified dendritic cells (DCs) simultaneously expressing carcinoembryonic antigen (CEA), granulocyte macrophage colony‐stimulating factor (GM‐CSF) and interleukin 12 (IL‐12) can overcome the peripheral T‐cell tolerance to CEA and thereby elicit a therapeutic response in CEA transgenic mice. CEA transgenic mice were immunized once by subcutaneous injection with DCs adenovirally transduced with CEA and T helper‐type 1 cytokine genes. The cytotoxic activity of spleen cells against CEA‐expressing tumors, MC38‐CEA, in the mice immunized with DCs expressing CEA (DC‐AxCACEA) was higher than that in those immunized with DCs‐AxCALacZ (p < 0.0001), and was augmented by the cotransduction with the GM‐CSF/IL‐12 gene (p < 0.05). The vaccination with DC‐AxCACEA/GM‐CSF/IL‐12 could elicit a more potent therapeutic immunity than the vaccination with DC‐AxCACEA in subcutaneous tumor models (p < 0.0001), and 4 of 5 mice showed a complete eradication of the subcutaneous tumors in these vaccination groups. Even in a large tumor model, this vaccination therapy completely eliminated the subcutaneous tumors in all mice. This antitumor activity mostly vanished with the depletion of CD8+ T cells and NK cells in vivo and was completely abrogated with the depletion of CD4+ T cells. A histopathological examination showed no evidence of an autoimmune reaction. No other adverse effects were observed. This vaccination strategy resulted in the generation of highly efficient therapeutic immune responses against MC38‐CEA in the absence of autoimmune responses and demonstrated no adverse effects, and may therefore be useful for future clinical applications as a cancer vaccine therapy.

Postoperative evaluation of pylorus-preserving procedures compared with conventional distal gastrectomy for early gastric cancer.

Abstract We evaluated postoperative function in 98 patients who underwent surgery for early gastric cancer between 1995 and 1998 to compare the results of pylorus-preserving procedures to those of conventional distal gastrectomy with Billroth I (B-I). The pylorus-preserving procedures included endoscopic mucosal resection (EMR), performed in 12 patients; local resection (Local), performed in 14 patients; segmental resection (Seg), performed in 8 patients; and pylorus-preserving gastrectomy (PPG), performed in 19 patients. B-I was performed in 45 patients. The nutritional status and serum albumin (Alb) levels after PPG, the hemoglobin (Hb) levels after EMR, Local, and PPG, and the present/preoperative body weight ratios after EMR, Local, Seg, and PPG were superior to those after B-I. The time before oral intake was recommenced after EMR and Local, the volume of oral intake tolerated after EMR, Local, Seg, and PPG, and the postoperative hospital stay after EMR were all superior to those after B-I. Moreover, significantly fewer patients suffered reflux symptoms after EMR, Local, and PPG, abdominal fullness after EMR, and early dumping syndrome after EMR, Local, and PPG than after B-I. There was also less evidence of gastritis after EMR, Local, and PPG, and of bile reflux after EMR, Local, and PPG, than after B-I. These findings indicate that pylorus-preserving procedures may result in a better postoperative quality of life for selected patients with early gastric cancer.

Vaccination with peptides derived from cancer-testis antigens in combination with CpG-7909 elicits strong specific CD8+ T cell response in patients with metastatic esophageal squamous cell carcinoma.

Potent helper action is necessary for peptide‐based vaccines to efficiently induce antitumor immune responses against advanced cancer. A phase I trial for advanced esophageal squamous cell carcinoma was carried out for patients with HLA‐A*2402 using epitope peptides derived from novel cancer‐testis antigens, LY6K and TTK, in combination with CpG‐7909 (NCT00669292). This study investigated the feasibility and the toxicity as well as induction of tumor antigen‐specific immune responses. Nine patients were vaccinated on days 1, 8, 15, and 22 of each 28‐day treatment cycle with peptide LY6K‐177, peptide TTK‐567, and CpG‐7909 (level‐1; 0, level‐2; 0.02, level‐3; 0.1 mg/kg) and all were tolerated by this treatment. LY6K‐specific T cell responses in PBMCs were detected in two of the three patients in each level. In particular, two patients in level‐2/3 showed potent LY6K‐specific T cell responses. In contrast, only two patients in level‐2/3 showed TTK‐567‐specific T cell responses. The frequency of LY6K‐177 or TTK‐567‐specific CD8+ T cells increased in patients in level‐2/3 (with CpG). The vaccination with peptides and CpG‐7909 increased and activated both plasmacytoid dentritic cells and natural killer cells, and increased the serum level of α‐interferon. There were no complete response (CR) and partial response (PR), however, one of three patients in level‐1, and four of six patients in level‐2/3 showed stable disease (SD). In conclusion, vaccination with LY6K‐177 and TTK‐567 in combination with CpG‐7909 successfully elicited antigen‐specific CD8+ T cell responses and enhanced the innate immunity of patients with advanced esophageal squamous cell carcinoma. This vaccine protocol is therefore recommended to undergo further phase II trials. (Cancer Sci 2010; 101: 2510–2517)

Clinicopathological characteristics of remnant gastric cancer after a distal gastrectomy.

IntroductionThe survival rate of patients with remnant gastric cancer (RGC) is unfavorable in comparison to that of cancer in the nonresected stomach. However, when RGC is curatively resected, no significant differences have been reported between both groups in regard to survival. The aim of this study is to analyze the clinicopathological factors influencing a curative resection of RGC.MethodsThirty-eight consecutive patients with RGC from January 1, 1994 through March 31, 2009 were enrolled in this retrospective study.ResultsTheir primary diseases were gastric cancers (21; 55.3%) and benign diseases (17; 44.7%). The type of the reconstruction methods of first gastrectomy were Billroth I (28; 73.7%) and Billroth II (10; 26.3%). A total of 31 patients underwent a laparotomy. Twenty patients underwent a curative resection, four patients underwent a palliative resection, and seven underwent a nonresective operation. A total of seven patients underwent an endoscopic resection for early gastric cancer, and all patients received a curative resection. Univariate and multivariate logistic regression analyses were performed to identify the clinicopathological and background factors influencing a curative resection of RGC. A multivariate analysis revealed only an annual follow-up endoscopic examination after the initial gastrectomy to be an independent factor for a curative resection (p = 0.016; odds ratio, 35.3).ConclusionsAn annual follow-up endoscopic examination an after initial gastrectomy may be related to improving the prognosis of patients with RGC.

Dendritic cells adenovirally-transduced with full-length mesothelin cDNA elicit mesothelin-specific cytotoxicity against pancreatic cancer cell lines in vitro

Mesothelin (MSLN) is an attractive candidate as a molecular target for pancreatic cancer immunotherapy. The purpose of this study was to demonstrate that cytotoxic T lymphocytes (CTLs) generated from peripheral blood mononuclear cells (PBMCs) by stimulation with genetically-modified dendritic cells (DCs) expressing MSLN could produce specific anti-tumor immunity against pancreatic cancer cells endogenously expressing MSLN. MSLN-specific CTLs were generated from PBMCs of healthy donors by in vitro stimulation with DCs adenovirally-transduced with the full-length MSLN gene (DC-AxCAMSLN). The cytotoxic activity was tested using a 4-h (51)Cr-release assay. The pancreatic cancer cell lines (PK1, CfPAC1, AsPC1), a lymphoblastoid cell lines (LCL) transduced with the MSLN gene, and LCL pulsed with MSLN-epitope peptides were used as target cells. MSLN-specific CTLs induced by in vitro stimulation with DC-AxCAMSLN killed pancreatic cancer cell lines expressing MSLN in an HLA-restricted fashion. These CTLs also showed cytotoxic activity against autologous LCL pulsed with multiple MSLN-derived epitope peptides. In addition, CD8(+) T cells, as well as CD4(+) T cells, sorted from these CTLs showed significant production of interferon-γ when stimulated with DC-AxCAMSLN. The in vitro stimulation of PBMCs with DCs transduced with the full-length MSLN gene elicited a potent MSLN-specific cytotoxic activity against pancreatic cancer cell lines endogenously expressing MSLN by recognizing multiple MSLN epitopes and activating both CD8(+) T cells and CD4(+) helper T cells. These results therefore suggest the potential of developing future clinical applications of the vaccines using genetically-modified DCs expressing MSLN.