Yoichi Toyama

Dendritic Cells Fused with Allogeneic Colorectal Cancer Cell Line Present Multiple Colorectal Cancer–Specific Antigens and Induce Antitumor Immunity against Autologous Tumor Cells

The aim of antitumor immunotherapy is to induce CTL responses against autologous tumors. Previous work has shown that fusion of human dendritic cells and autologous tumor cells induce CTL responses against autologous tumor cells in vitro. However, in the clinical setting of patients with colorectal carcinoma, a major difficulty is the preparation of sufficient amounts of autologous tumor cells. In the present study, autologous dendritic cells from patients with colorectal carcinoma were fused to allogeneic colorectal tumor cell line, COLM-6 (HLA-A2−/HLA-24−), carcinoembryonic antigen (CEA)+, and MUC1+ as an alternative strategy to deliver shared colorectal carcinoma antigens to dendritic cells. Stimulation of autologous T cells by the fusion cells generated with autologous dendritic cells (HLA-A2+ and/or HLA-A24+) and allogeneic COLM-6 resulted in MHC class I– and MHC class II–restricted proliferation of CD4+ and CD8+ T cells, high levels of IFN-γ production in both CD4+ and CD8+ T cells, and the simultaneous induction of CEA- and MUC1-specific CTL responses restricted by HLA-A2 and/or HLA-A24. Finally, CTL induced by dendritic cell/allogeneic COLM-6 fusion cells were able to kill autologous colorectal carcinoma by HLA-A2- and/or HLA-A24-restricted mechanisms. The demonstration of CTL activity against shared tumor-associated antigens using an allogeneic tumor cell line, COLM-6, provides that the presence of alloantigens does not prevent the development of CTL with activity against autologous colorectal carcinoma cells. The fusion of allogeneic colorectal carcinoma cell line and autologous dendritic cells could have potential applicability to the field of antitumor immunotherapy through the cross-priming against shared tumor antigens and provides a platform for adoptive immunotherapy.

Wilms tumor gene (WT1) peptide-based cancer vaccine combined with gemcitabine for patients with advanced pancreatic cancer.

Wilms tumor gene (WT1) protein is an attractive target for cancer immunotherapy. We aimed to investigate the feasibility of a combination therapy consisting of gemcitabine and WT1 peptide–based vaccine for patients with advanced pancreatic cancer and to make initial assessments of its clinical efficacy and immunologic response. Thirty-two HLA-A*24:02+ patients with advanced pancreatic cancer were enrolled. Patients received HLA-A*24:02-restricted, modified 9-mer WT1 peptide (3 mg/body) emulsified with Montanide ISA51 adjuvant (WT1 vaccine) intradermally biweekly and gemcitabine (1000 mg/m2) on days 1, 8, and 15 of a 28-day cycle. This combination therapy was well tolerated. The frequencies of grade 3–4 adverse events for this combination therapy were similar to those for gemcitabine alone. Objective response rate was 20.0% (6/30 evaluable patients). Median survival time and 1-year survival rate were 8.1 months and 29%, respectively. The association between longer survival and positive delayed-type hypersensitivity to WT1 peptide was statistically significant, and longer survivors featured a higher frequency of memory-phenotype WT1-specific cytotoxic T lymphocytes both before and after treatment. WT1 vaccine in combination with gemcitabine was well tolerated for patients with advanced pancreatic cancer. Delayed-type hypersensitivity-positivity to WT1 peptide and a higher frequency of memory-phenotype WT1-specific cytotoxic T lymphocytes could be useful prognostic markers for survival in the combination therapy with gemcitabine and WT1 vaccine. Further clinical investigation is warranted to determine the effectiveness of this combination therapy.

Multicenter comparative study of laparoscopic and open distal pancreatectomy using propensity score-matching

Laparoscopic distal pancreatectomy has been shown to be associated with favorable postoperative outcomes using meta‐analysis. However, there have been no randomized controlled studies yet. This study aimed to compare laparoscopic and open distal pancreatectomy using propensity score‐matching.

Streptococcal Preparation OK-432 Promotes Fusion Efficiency and Enhances Induction of Antigen-Specific CTL by Fusions of Dendritic Cells and Colorectal Cancer Cells

Dendritic/tumor fusion cell (FC) vaccine is an effective approach for various types of cancer but has not yet been standardized. Antitumor activity can be modulated by different mechanisms such as dendritic cell (DC) maturation state. This study addressed optimal strategies for FC preparations to enhance Ag-specific CTL activity. We have created three types of FC preparations by alternating fusion cell partners: 1) immature DCs fused with autologous colorectal carcinoma cells (Imm-FCs); 2) Imm-FCs followed by stimulation with penicillin-inactivated Streptococcus pyogenes (OK-432) (Imm-FCs/OK); and 3) OK-432-stimulated DCs directly fused to autologous colorectal carcinoma cells (OK-FCs). Both OK-FCs and Imm-FCs/OK coexpressed the CEA, MUC1, and significantly higher levels of CD86, CD83, and IL-12 than those obtained with Imm-FCs. Short-term culture of fusion cell preparations promoted the fusion efficiency. Interestingly, OK-FCs were more efficient in stimulating CD4+ and CD8+ T cells capable of high levels of IFN-γ production and cytolysis of autologous tumor or semiallogeneic targets. Moreover, OK-FCs are more effective inducer of CTL activation compared with Imm-FCs/OK on a per fusion cell basis. The pentameric assay confirmed that CEA- and MUC1-specific CTL was induced simultaneously by OK-FCs at high frequency. Furthermore, the cryopreserved OK-FCs retained stimulatory capacity for inducing antitumor immunity. These results suggest that OK-432 promotes fusion efficiency and induction of Ag-specific CTL by fusion cells. We conclude that DCs fused after stimulation by OK-432 may have the potential applicability to the field of antitumor immunotherapy and may provide a platform for adoptive immunotherapy in the clinical setting.

Induction of antigen-specific CD4- and CD8-mediated T-cell responses by fusions of autologous dendritic cells and metastatic colorectal cancer cells.

Human metastatic colorectal carcinomas (CRCAs) express carcinoembryonic antigen (CEA) and/or MUC1 tumor‐associated antigens as potential targets for the induction of active specific immunity. In the present study, freshly isolated metastatic CRCA cells were successfully fused with immature autologous human monocyte‐derived dendritic cells (DCs). The created heterokaryons (DC/CRCA) coexpress the CRCA‐derived CEA and MUC1 antigens and DC‐derived MHC class II and costimulatory molecules. The fusion cells were functional in stimulating the proliferation of autologous T cells. In addition, both CD4+ and CD8+ T cells were activated by fusion cells, as demonstrated by the production of high levels of IFN‐γ. More importantly, coculture of fusion cells with patient‐derived peripheral blood mononuclear cells (PBMCs) resulted in the induction of antigen‐specific cytotoxic T lymphocytes (CTLs). CTLs were effective at lysis of not only autologous CRCA cells but also the CEA and/or MUC1‐positive and HLA partially matched target cells. Antigen‐specific CTL responses were confirmed by tetrameric analysis. Coculture of PBMCs with fusion cells resulted in increased frequency of CEA‐ and MUC1‐specific CTLs simultaneously. Taken together, these results indicate that freshly isolated human metastatic CRCA cells expressing the CEA and/or MUC1 may represent a potential partner for the creation of DC/tumor fusion cells targeting induction of antigen‐specific CTL responses. Our report demonstrates the simultaneous induction of CRCA‐specific CTL responses restricted by HLA‐A2 and ‐A24.

Synergistic Induction of Antigen-Specific CTL by Fusions of TLR-Stimulated Dendritic Cells and Heat-Stressed Tumor Cells

Dendritic cell (DC)/tumor cell fusion cells (FCs) can induce potent CTL responses. The therapeutic efficacy of a vaccine requires the improved immunogenicity of both DCs and tumor cells. The DCs stimulated with the TLR agonist penicillin-killed Streptococcus pyogenes (OK-432; OK-DCs) showed higher expression levels of MHC class I and II, CD80, CD86, CD83, IL-12, and heat shock proteins (HSPs) than did immature DCs. Moreover, heat-treated autologous tumor cells displayed a characteristic phenotype with increased expression of HSPs, carcinoembryonic Ag (CEA), MUC1, and MHC class I (HLA-A2 and/or A24). In this study, we have created four types of FC preparation by alternating fusion cell partners: 1) immature DCs fused with unheated tumor cells; 2) immature DCs fused with heat-treated tumor cells; 3) OK-DCs fused with unheated tumor cells; and 4) OK-DCs fused with heat-treated tumor cells. Although OK-DCs fused with unheated tumor cells efficiently enhanced CTL induction, OK-DCs fused with heat-treated tumor cells were most active, as demonstrated by: 1) up-regulation of multiple HSPs, MHC class I and II, CEA, CD80, CD86, CD83, and IL-12; 2) activation of CD4+ and CD8+ T cells able to produce IFN- γ at higher levels; 3) efficient induction of CTL activity specific for CEA or MUC1 or both against autologous tumor; and 4) superior abilities to induce CD107+IFN-γ+CD8+ T cells and CD154+ IFN-γ+CD4+ T cells. These results strongly suggest that synergism between OK-DCs and heat-treated tumor cells enhances the immunogenicity of FCs and provides a promising means of inducing therapeutic antitumor immunity.

Is modified devine exclusion necessary for gastrojejunostomy in patients with unresectable pancreatobiliary cancer

PurposeGastrojejunostomy is often performed as palliative surgery for unresectable pancreatobiliary cancer. Modified Devine exclusion (MDE) is a technical variation of gastrojejunostomy, which partially separates the mid-portion of the stomach. We conducted this study to assess whether MDE is necessary for gastrojejunostomy in patients with unresectable pancreatobiliary cancer.MethodsWe compared the postoperative results of MDE (n = 26) with those of conventional gastrojejunostomy (CGJ; n = 20) performed palliatively for unresectable pancreatobiliary cancers.ResultsThe morbidity rates were 38% after MDE and 50% after CGJ, with 23% and 40% of patients suffering delayed gastric emptying, respectively. Two of the CGJ group patients could never eat again. Modified Devine exclusion slowed the progression of anemia in all of the patients with duodenal bleeding.ConclusionModified Devine exclusion may be effective for patients with unresectable pancreatobiliary cancer.

Transumbilical single-incision laparoscopic hepatectomy using precoagulation and clipless technique in a patient with combined hepatocellular-cholangiocarcinoma: a case report.

We report our first case of single-incision laparoscopic hepatectomy in a 43-year-old woman with a 30-mm solitary combined hepatocellular-cholangiocarcinoma. A port of single-incision laparoscopic surgery was inserted through the abdominal wall using a 2.5-cm single incision in the umbilical area. To obtain adequate operative view for the tumor in segment 6, a 5-mm flexible endoscope, roticulated instruments, and a miniloop retractor were used. After precoagulation with a 5-mm flexible microwave probe, liver resection was performed using laparoscopic ultrasonic shears, soft-coagulation devices, and a tissue-sealing knife. Subsequently, cholecystectomy was carried out for a gallbladder polyp. The procedure was successfully completed without conversion to conventional laparoscopic technique. The operation time was 180 minutes and operative blood loss was uncountable. Transumbilical single-incision laparoscopic hepatectomy using precoagulation and clipless techniques is feasible and seems to provide better cosmetic appearance in selected cases by qualified endoscopic liver surgeons.

Successful adjuvant bi-weekly gemcitabine chemotherapy for pancreatic cancer without impairing patients’ quality of life

BackgroundAlthough adjuvant gemcitabine (GEM) chemotherapy for pancreatic cancer is standard, the quality of life (QOL) in those patients is still impaired by the standard regimen of GEM. Therefore, we studied whether mild dose-intensity adjuvant chemotherapy with bi-weekly GEM administration could provide a survival benefit with acceptable QOL to the patients with pancreatic cancer.MethodsAfter a phase I trial, an adjuvant bi-weekly 1,000 mg/m2 of GEM chemotherapy was performed in 58 patients with pancreatic cancer for at least 12 courses (Group A). In contrast, 36 patients who declined the adjuvant bi-weekly GEM chemotherapy underwent traditional adjuvant 5FU-based chemotherapy (Group B). Careful periodical follow-ups for side effects of GEM and disease recurrence, and assessment of patients’ QOL using the EORTC QOL questionnaire (QLQ-C30) and pancreatic cancer-specific supplemental module (QLQ-PAN26) were performed. Retrospectively, the degree of side effects, patients’ QOL, compliance rate, disease-free survival (DFS), and overall survival (OS) in Group A were compared with those in Group B.ResultsNo severe side effects (higher than Grade 2 according to the common toxicity criteria of ECOG) were observed, except for patients in Group B, who were switched to the standard GEM chemotherapy. Patients’ QOL was better in Group A than B (fatigue: 48.9 ± 32.1 versus 68.1 ± 36.3, nausea and vomiting: 26.8 ± 20.4 versus 53.7 ± 32.6, diarrhea: 21.0 ± 22.6 versus 53.9 ± 38.5, difficulty gaining weight: 49.5 ± 34.4 versus 67.7 ± 40.5, P < 0.05). Compliance rates in Groups A and B were 93% and 47%. There was a significant difference in the median DFS between both groups (Group A : B =12.5 : 6.6 months, P < 0.001). The median OS of Group A was prolonged markedly compared with Group B (20.2 versus 11.9 months, P < 0.005). For OS between both groups, univariate analysis revealed no statistical difference in 69-year-old or under females, and T1–2 factors, moreover, multivariate analysis indicated three factors, such as bi-weekly adjuvant GEM chemotherapy, T2 or less, and R0.ConclusionsAdjuvant chemotherapy with bi-weekly GEM offered not only the advantage of survival benefits but the excellent compliance with acceptable QOL for postoperative pancreatic cancer patients.

Abstract CT218: Wilms′ tumor gene 1 (WT1) peptide-based cancer vaccine combined with gemcitabine for patients with advanced pancreatic cancer

Proceedings: AACR Annual Meeting 2014; April 5-9, 2014; San Diego, CA Wilms′ tumor gene 1 (WT1) protein is an attractive target for cancer immunotherapy. To investigate the feasibility of a combination therapy consisting of gemcitabine and WT1 peptide for patients with advanced pancreatic cancer, 32 HLA-A*24:02-positive patients were enrolled. HLA-A*24:02-restricted, modified 9-mer WT1 peptide (3 mg) emulsified with Montanide ISA51 adjuvant (WT1 vaccine) was injected intradermally biweekly. Moreover, gemcitabine (1,000 mg/m2) was administrated on days 1, 8, and 15 of a 28-day cycle. Median survival time and one-year survival rate were 8.1 months and 29%, respectively. The association between longer survival and positive delayed-type hypersensitivity (DTH) to WT1 peptide alone was statistically significant, and longer survivors featured a higher frequency of memory-phenotype WT1-specific cytotoxic T-lymphocytes (CTLs) before and during treatment. In conclusion, the combination therapy was well-tolerated and promising treatment for advanced pancreatic cancer. DTH-positivity to WT1 peptide alone and a higher frequency of memory-phenotype WT1-specific CTLs could be useful predictive markers for clinical efficacy. Citation Format: Shigeo Koido, Sumiyuki Nishida, Sadamu Homma, Yutaka Takeda, Hideo Komita, Satoshi Morita, Toshinori Ito, Soyoko Morimoto, Yoshihiro Oka, Satoru Yanagisawa, Yoichi Toyama, Masahiro Ikegami, Hiroaki Nagano, Toshifumi Ohkusa, Hisao Tajiri, Haruo Sugiyama. Wilms′ tumor gene 1 (WT1) peptide-based cancer vaccine combined with gemcitabine for patients with advanced pancreatic cancer. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr CT218. doi:10.1158/1538-7445.AM2014-CT218