Vaccination with liposome-coupled glypican-3-derived epitope peptide stimulates cytotoxic T lymphocytes and inhibits GPC3-expressing tumor growth in mice

AbstractBecause therapeutic manipulation of immunity can induce tumor regression, anti-cancer immunotherapy is considered a promising treatment modality. We previously reported that glypican-3 (GPC3), an oncofetal antigen overexpressed in hepatocellular carcinoma (HCC), is a useful target for cytotoxic T lymphocyte (CTL)-mediated cancer immunotherapy, and we have performed clinical trials using the GPC3-derived peptide vaccine. Although vaccine-induced GPC3-peptide-specific CTLs were often tumor reactive in vitro and were correlated with overall survival, no complete response was observed. In the current study, we synthesized liposome-coupled GPC3-derived CTL epitope peptide (pGPC3-lipsome) and investigated its antitumor potential. Vaccination with pGPC3-liposome induced peptide-specific CTLs at a lower dose than conventional vaccine emulsified in incomplete Freund's adjuvant. Coupling of pGPC3 to liposomes was essential for effective priming of GPC3-specific CTLs. In addition, immunization with pGPC3-liposome inhibited GPC3-expressing tumor growth. Thus, vaccination with tumor-associated antigen-derived epitope peptides coupled to the surfaces of liposomes may be a novel therapeutic strategy for cancer

Intratumoral peptide injection enhances tumor cell antigenicity recognized by cytotoxic T lymphocytes: a potential option for improvement in antigen-specific cancer immunotherapy

Antigen-specific cancer immunotherapy is a promising strategy for improving cancer treatment. Recently, many tumor-associated antigens and their epitopes recognized by cytotoxic T lymphocytes (CTLs) have been identified. However, the density of endogenously presented antigen-derived peptides on tumor cells is generally sparse, resulting in the inability of antigen-specific CTLs to work effectively. We hypothesize that increasing the density of an antigen-derived peptide would enhance antigen-specific cancer immunotherapy. Here, we demonstrated that intratumoral peptide injection leads to additional peptide loading onto major histocompatibility complex class I molecules of tumor cells, enhancing tumor cell recognition by antigen-specific CTLs. In in vitro studies, human leukocyte antigen (HLA)-A*02:01-restricted glypican-3(144-152) (FVGEFFTDV) and cytomegalovirus(495-503) (NLVPMVATV) peptide-specific CTLs showed strong activity against all peptide-pulsed cell lines, regardless of whether the tumor cells expressed the antigen. In in vivo studies using immunodeficient mice, glypican-3(144-152) and cytomegalovirus(495-503) peptides injected into a solid mass were loaded onto HLA class I molecules of tumor cells. In a peptide vaccine model and an adoptive cell transfer model using C57BL/6 mice, intratumoral injection of ovalbumin(257-264) peptide (SIINFEKL) was effective for tumor growth inhibition and survival against ovalbumin-negative tumors without adverse reactions. Moreover, we demonstrated an antigen-spreading effect that occurred after intratumoral peptide injection. Intratumoral peptide injection enhances tumor cell antigenicity and may be a useful option for improvement in antigen-specific cancer immunotherapy against solid tumors

Organoids with cancer stem cell-like properties secrete exosomes and HSP90 in a 3D nanoenvironment

Ability to form cellular aggregations such as tumorspheres and spheroids have been used as a morphological marker of malignant cancer cells and in particular cancer stem cells (CSC). However, the common definition of the types of cellular aggregation formed by cancer cells has not been available. We examined morphologies of 67 cell lines cultured on three dimensional morphology enhancing NanoCulture Plates (NCP) and classified the types of cellular aggregates that form. Among the 67 cell lines, 49 cell lines formed spheres or spheroids, 8 cell lines formed grape-like aggregation (GLA), 8 cell lines formed other types of aggregation, and 3 cell lines formed monolayer sheets. Seven GLA-forming cell lines were derived from adenocarcinoma among the 8 lines. A neuroendocrine adenocarcinoma cell line PC-3 formed asymmetric GLA with ductal structures on the NCPs and rapidly growing asymmetric tumors that metastasized to lymph nodes in immunocompromised mice. In contrast, another adenocarcinoma cell line DU-145 formed spheroids in vitro and spheroid-like tumors in vivo that did not metastasize to lymph nodes until day 50 after transplantation. Culture in the 3D nanoenvironment and in a defined stem cell medium enabled the neuroendocrine adenocarcinoma cells to form slowly growing large organoids that expressed multiple stem cell markers, neuroendocrine markers, intercellular adhesion molecules, and oncogenes in vitro. In contrast, the more commonly used 2D serum-contained environment reduced intercellular adhesion and induced mesenchymal transition and promoted rapid growth of the cells. In addition, the 3D stemness nanoenvironment promoted secretion of HSP90 and EpCAM-exosomes, a marker of CSC phenotype, from the neuroendocrine organoids. These findings indicate that the NCP-based 3D environment enables cells to form stem cell tumoroids with multipotency and model more accurately the in vivo tumor status at the levels of morphology and gene expression

Enhancement of antitumor effect by peptide vaccine therapy in combination with anti-CD4 antibody: Study in a murine model

Purpose: The clinical efficacy of cancer peptide vaccine therapy is insufficient. To enhance the anti-tumor effect of peptide vaccine therapy, we combined this therapy with an anti-CD4 mAb (GK1.5), which is known to deplete CD4+ cells, including regulatory T cells (Tregs). Methods: To determine the treatment schedule, the number of lymphocyte subsets in the peripheral blood of mice was traced by flow cytometry after administration of anti-CD4 mAb. The ovalbumin (OVA)257–264 peptide vaccine was injected intradermally and anti-CD4 mAb was administered intraperitoneally into C57BL/6 mice at different schedules. We evaluated the enhancement of OVA peptide-specific cytotoxic T lymphocyte (CTL) induction in the combination therapy using the ELISPOT assay, CD107a assay, and cytokine assay. We then examined the in vivo metastasis inhibitory effect by OVA peptide vaccine therapy in combination with anti-CD4 mAb against OVA-expressing thymoma (EG7) in a murine liver metastatic model. Results: We showed that peptide-specific CTL induction was enhanced by the peptide vaccine in combination with anti-CD4 mAb and that the optimized treatment schedule had the strongest induction effect of peptide-specific CTLs using an IFN-γ ELISPOT assay. We also confirmed that the CD107a+ cells secreted perforin and granzyme B and the amount of IL-2 and TNF produced by these CTLs increased when the peptide vaccine was combined with anti-CD4 mAb. Furthermore, metastasis was inhibited by peptide vaccines in combination with anti-CD4 mAb compared to peptide vaccine alone in a murine liver metastatic model. Conclusion: The use of anti-CD4 mAb in combination with the OVA peptide vaccine therapy increased the number of peptide-specific CTLs and showed a higher therapeutic effect against OVA-expressing tumors. The combination with anti-CD4 mAb may provide a new cancer vaccine strategy

Association between meat, fish, and fatty acid intake and incidence of acute myeloid leukemia and myelodysplastic syndrome: the Japan Public Health Center-based Prospective Study

Background: The association between meat, fish, or fatty acid intake and acute myeloid leukemia (AML) and myelodysplastic syndrome (MDS) has been investigated in a few studies, and the results were inconsistent. In addition, most studies are mainly based on the United States and European countries, in which the dietary patterns differ from that in Asia. Therefore, the risk of AML/MDS from meat, fish, or fatty acid intake in Asia requires further exploration. The aim of this study was to investigate the association between AML/MDS incidence and meat, fish, or fatty acid intake using the Japan Public Health Center–based prospective study. Methods: The present study included 93,366 participants who were eligible for analysis and followed up from the 5-year survey date until December 2012. We estimated the impact of their intake on AML/MDS incidence using a Cox proportional hazards model. Results: The study participants were followed up for 1,345,002 person-years. During the follow-up period, we identified 67 AML and 49 MDS cases. An increased intake of processed red meat was significantly associated with the incidence of AML/MDS, with a hazard ratio of 1.63 (95% confidence interval, 1.03–2.57) for the highest versus lowest tertile and a Ptrend of 0.04. Meanwhile, the intake of other foods and fatty acids was not associated with AML/MDS. Conclusion: In this Japanese population, processed red meat was associated with an increased incidence of AML/MDS

Ki67 expression and localization of T cells after neoadjuvant therapies as reliable predictive markers in rectal cancer

Chemoradiotherapy (CRT) is the standard neoadjuvant therapy for locally advanced rectal cancer (RC). However, neoadjuvant chemotherapy (NAC) also shows favorable outcomes. Although the immunological environment of RC has been thoroughly discussed, the effect of NAC on it is less clear. Here, we investigated the immunological microenvironment, including T cell infiltration, activation, and topological distribution, of resected RC tissue after neoadjuvant therapies and evaluated the correlation between T cell subsets and patient prognosis. Rectal cancer patients (n = 188) were enrolled and categorized into 3 groups, namely CRT (n = 41), NAC (n = 46), and control (surgery alone; n = 101) groups. Characterization of residual carcinoma cells and T cell subsets in resected tissues was performed using multiplex fluorescence immunohistochemistry. The densities of total and activated (Ki67(high)) T cells in tissues after NAC, but not CRT, were higher than in control. In both CRT and NAC groups, patients presenting with higher treatment effects showed aggressive infiltration of T cell subsets into carcinomas. Multivariate analyses of pathological and immunological features and prognosis revealed that carcinoma Ki67(high)CD4(+) T cells after CRT and stromal Ki67(high)CD8(+) T cells after NAC are important prognostic factors, respectively. Our results suggest that evaluation of T cell activation with Ki67 expression and its tumor localization can be used to determine the prognosis of advanced RC after neoadjuvant therapies

Ki67 expression and localization of T cells after neoadjuvant therapies as reliable predictive markers in rectal cancer

Chemoradiotherapy (CRT) is the standard neoadjuvant therapy for locally advanced rectal cancer (RC). However, neoadjuvant chemotherapy (NAC) also shows favorable outcomes. Although the immunological environment of RC has been thoroughly discussed, the effect of NAC on it is less clear. Here, we investigated the immunological microenvironment, including T cell infiltration, activation, and topological distribution, of resected RC tissue after neoadjuvant therapies and evaluated the correlation between T cell subsets and patient prognosis. Rectal cancer patients (n = 188) were enrolled and categorized into 3 groups, namely CRT (n = 41), NAC (n = 46), and control (surgery alone; n = 101) groups. Characterization of residual carcinoma cells and T cell subsets in resected tissues was performed using multiplex fluorescence immunohistochemistry. The densities of total and activated (Ki67(high)) T cells in tissues after NAC, but not CRT, were higher than in control. In both CRT and NAC groups, patients presenting with higher treatment effects showed aggressive infiltration of T cell subsets into carcinomas. Multivariate analyses of pathological and immunological features and prognosis revealed that carcinoma Ki67(high)CD4(+) T cells after CRT and stromal Ki67(high)CD8(+) T cells after NAC are important prognostic factors, respectively. Our results suggest that evaluation of T cell activation with Ki67 expression and its tumor localization can be used to determine the prognosis of advanced RC after neoadjuvant therapies

Pancreatic juice outflow in pancreatojejunostomy monitoring with the inter-anastomosis drainage tube; a retrospective observational study

Abstract Background Pancreatic fistula remains the biggest problem in pancreatic surgery. We have previously reported a new pancreatojejunostomy method using an inter-anastomosis drainage (IAD) suction tube with Blumgart anastomosis for drainage of the pancreatic juice leaking from the branched pancreatic ducts. This study aimed to evaluate the postoperative outcomes of our novel method, in pancreatojejunostomy and investigate the nature of the inter-anastomosis space between jejunal wall and pancreas parenchyma. Methods This retrospectively study consist of 282 pancreatoduodenectomy cases, including 86 reconstructions via the Blumgart method plus IAD (B + IAD group) and 196 cases reconstructed using the Blumgart method alone (B group). Postoperative outcomes and the amylase value and the volume of the drainage fluids were compared between the two groups. The IAD tube was placed to collect amylase-rich fluid from the inter-anastomosis space during operative procedure between the jejunal wall and pancreatic stump. Results The daily IAD drainage volume and the amylase level was significantly higher in patients with a soft pancreas (vs hard pancreas; 16.5 vs. 10.0 mL/day, p = 0.012; 90,900 vs. 1634 IU/L, p < 0.001, respectively). The mean amylase value of IAD collection in 86 cases of B + IAD group was 63,100 IU/L. The incidence of clinically relevant pancreatic fistula grade B and C (23.2% vs. 23.0%, p = 0.55) and the hospital stay was similar between the groups (median 17 vs. 18 days, p = 0.55). In 176 patients with soft pancreas, the incidence of pancreatic fistula grade B and C (33.3% vs. 35.3%, p = 0.67) and the hospital stay was also similar between the groups (median 22.5 vs. 21 days, p = 0.81). Conclusions Positive effect of the IAD method observed in the pilot cases was not reproduced in the current study. IAD tube objectively demonstrated the existence of amylase-rich discharge at the anastomosis site, and countermeasures to eliminate this liquid are highly desired for preventing pancreatic fistula, especially in patients with soft pancreatic texture. Trial registration Retrospectively registere

Retrospective analysis of neoadjuvant chemotherapy followed by surgery versus definitive chemoradiotherapy with proton beam for locally advanced esophageal squamous cell carcinoma

BackgroundThis is the first study to compare the long-term outcomes between neoadjuvant chemotherapy + surgery and definitive chemoradiotherapy with proton beam therapy for locally advanced esophageal squamous cell carcinoma.MethodsWe reviewed patients with clinical stage IB–III esophageal squamous cell carcinoma (UICC 7th edition) who underwent neoadjuvant chemotherapy + surgery or definitive chemoradiotherapy with proton beam therapy (2009–2017). Overall survival, progression-free survival, and recurrence or regrowth rates were compared between the two treatment groups. Subgroup analyses of overall survival according to baseline characteristics were also performed.ResultsForty-three patients received neoadjuvant chemotherapy + surgery (median follow-up 47.4 months) and 60 received definitive chemoradiotherapy with proton beam therapy (median follow-up 51.5 months). Baseline characteristics were similar between the groups except for sex, tumor location, and cT classification. The neoadjuvant chemotherapy + surgery and definitive chemoradiotherapy with proton beam therapy groups had similar 3-year overall survival rates (73.1% and 61.7%, respectively, hazard ratio: 0.88, 95% confidence interval 0.49–1.58, p = 0.66), 3-year progression-free survival rates (46.5% and 45%, respectively, hazard ratio: 1.03, 95% confidence interval 0.62–1.70, p = 0.92), and recurrence or regrowth rates (53.5% vs. 50.0%, p = 0.84). In the subgroup analysis, favorable survival was observed after definitive chemoradiotherapy with proton beam therapy for cT1–2 disease (hazard ratio 2.58, 95% confidence interval 0.84–7.99) and after neoadjuvant chemotherapy + surgery for cT3 or higher disease (hazard ratio 0.32, 95% confidence interval 0.15–0.67, p-for-interaction = 0.002).ConclusionsLong-term outcomes were comparable between the treatments. The choice of the treatment according to cT classification might affect survival