Metformin inhibits TGF­ß1­induced epithelial­mesenchymal transition and liver metastasis of pancreatic cancer cells.

Epithelial­mesenchymal transition (EMT) is considered a crucial event in the development of cancer metastasis. Metformin is a drug used in the treatment of type 2 diabetes. Recently, increasing evidence has indicated that metformin possesses anti­tumor activities. However, the effects of metformin on EMT and metastases in pancreatic cancer remain unknown. Thus, the present study investigated whether metformin inhibits EMT of human pancreatic cancer cell lines. Pancreatic cancer cells were stimulated with transforming growth factor ß1 (TGF­ß1), an activator of EMT signaling, with or without metformin. After 48 h, the levels of epithelial and mesenchymal markers were evaluated by western blot analysis, immunocytochemistry and RT­qPCR. Cancer cell migration was evaluated by an in vitro wound healing assay. The cells stimulated with TGF­ß1 acquired an elongated and fusiform morphology, which was inhibited by metformin. The wound healing assay revealed that metformin significantly suppressed the TGF­ß1­stimulated migration of pancreatic cancer cells. Following treatment with metformin, E­cadherin expression (epithelial marker) was upregulated, and the levels of mesenchymal markers were downregulated, which had been increased by TGF­ß1 in these cells. Exposure of the cells to TGF­ß1 activated the Smad2/3 and Akt/mammalian target of rapamycin (mTOR) pathways, and this effect was inhibited by metformin, suggesting that metformin inhibits TGF­ß1­induced­EMT through the down­regulation of the Smad pathway in PANC­1 cells and the downregulation of the Akt/mTOR pathway in BxPC­3 cells. In an animal model of surgical orthotopic implantation, metformin inhibited liver metastasis without a significant reduction in the size of the primary pancreatic tumor. On the whole, the findings of the present study suggest that metformin inhibits EMT and cancer metastasis through the Smad or Akt/mTOR pathway.

Clinical significance of soluble forms of immune checkpoint molecules in advanced esophageal cancer.

Immune checkpoint molecules are expressed on cancer cells and regulate tumor immunity by binding to ligands on immune cells. Although soluble forms of immune checkpoint molecules have been detected in the blood of patients with some types of tumors, their roles have not been fully elucidated. Soluble PD-L1, PD-1, CD155, LAG3, and CD226 (sPD-L1, sPD-1, sCD155, sLAG3, and sCD226, respectively) were measured in the sera of 47 patients with advanced esophageal cancer and compared with those of 24 control subjects. Pretreatment levels of sPD-1 and sCD155 were significantly higher in the patients with cancer than in the control subjects (P = 0.023, P = 0.001). The sPD-1 levels tended to be higher in the patients with lymph node metastasis, a large tumor diameter, and higher levels of serum SCC antigen (P = 0.150, P = 0.189, and P = 0.078, respectively). However, higher levels of sCD155 were associated with a better response to chemotherapy and favorable overall survival (P = 0.111 and P = 0.068, respectively). After 2 courses of chemotherapy, the levels of sCD155 and sCD226 were significantly increased (P < 0.001 and P = 0.002, respectively). Moreover, the increase in sCD226 during chemotherapy was associated with poor treatment response (P = 0.019). sPD-1 levels are possibly dependent on the tumor aggressiveness of the esophageal cancer. Furthermore, the pretreatment levels of sCD155 and kinetic change of sCD226 after chemotherapy may be used as biomarkers of the treatment response and prognosis in patients with esophageal cancer.

Skeletal muscle mass as a predictor of the response to neo-adjuvant chemotherapy in locally advanced esophageal cancer.

Undernutrition and sarcopenia are associated with a higher incidence of chemotherapy-related toxicity and a poor prognosis in several kinds of cancer, but the impact of sarcopenia on the outcomes of chemotherapy for esophageal cancer remains unclear. Thus, the purpose of this retrospective study was to investigate whether sarcopenia affects the efficacy and toxicities of chemotherapy for advanced esophageal cancer patients. Data were collected from 31 esophageal cancer patients who underwent neo-adjuvant chemotherapy followed by surgery. Body composition was assessed at the start of chemotherapy by bioelectrical impedance analysis, and outcomes of chemotherapy were compared between sarcopenic and non-sarcopenic groups. Of the 31 patients, sarcopenia was observed in 16 (51.6%). The incidence of toxicities was not different between the two groups. However, as for pathologic response, a good therapeutic effect (Grade 2 or higher) was more common in the non-sarcopenic group than in the sarcopenic group (53.3% vs. 25.0%). Multivariate analysis showed that sarcopenia was an independent predictor of poor pathological response (odds ratio 8.02; P = 0.037). The results of this study suggest the potential utility of sarcopenia assessment in neoadjuvant patient selection strategies.

Phase I clinical trial of adoptive transfer of expanded natural killer cells in combination with IgG1 antibody in patients with gastric or colorectal cancer.

Natural killer (NK) cells exhibit strong cytotoxic activity against tumor cells without prior sensitization, and have the potential to exert antibody-dependent cellular cytotoxicity (ADCC). In this clinical trial, we examined the safety and efficacy of the use of NK cells, generated using a novel expansion system, in combination with IgG1 antibodies for the treatment of advanced gastric or colorectal cancers. Treatment consisted of trastuzumab- or cetuximab-based chemotherapy, plus adoptive NK cell therapy. For administration of expanded NK cells, dose escalation with a sequential 3 + 3 design was performed in three steps, at doses of 0.5 × 109 , 1.0 × 109 , and 2.0 × 109 cells/injection (N = 9). After 3 days of IgG1 antibody administration, patients were infused with expanded NK cells three times at triweekly intervals. NK cell populations expanded with our system were confirmed as being enriched in NK cells (median 92.9%) with high expression of NKG2D (97.6%) and CD16 (69.6%). The combination therapy was very well tolerated with no severe adverse events. Among six evaluable patients, four presented stable disease (SD) and two presented progressive disease. Of the four SD patients, three showed an overall decrease in tumor size after combination therapy. Immune monitoring suggested that combination therapy enhanced whole blood IFN-γ production and reduced peripheral regulatory T cells (Tregs). In conclusion, this phase I trial provides evidence of good tolerability, induction of Th1 immune responses, and preliminary anti-tumor activity for this combination therapy, in patients with advanced gastric and colorectal cancer that have received previous therapy.

The JAK/STAT pathway is involved in the upregulation of PD-L1 expression in pancreatic cancer cell lines.

Although improvements in the chemotherapy modalities for pancreatic cancer have been realized, pancreatic cancer remains one of the most lethal malignancies. New-generation cancer immunotherapy methods, such as blocking of the PD-1/PD-L1 pathway, are consistently being investigated to improve the survival of pancreatic cancer patients. In the present study, we evaluated the influence of anticancer agents 5-fluorouracil, gemcitabine and paclitaxel on PD-L1 expression in human pancreatic cancer cell lines MIA PaCa-2 and AsPC-1 and in murine pancreatic cancer cell line Pan02. Additionally, we analyzed the molecular mechanisms that facilitated the regulation of PD-L1 expression in these cell lines. We observed that when AsPC-1, MIA PaCa-2 and Pan02 cells were stimulated by 5-fluorouracil, gemcitabine or paclitaxel, PD-L1 surface protein expression was enhanced. Similarly, the mRNA level of PD-L1 was upregulated in the AsPC-1 and Pan02 cells when stimulated by each of the three anticancer agents. The phosphorylation of STAT1 and an increase in total STAT1 were also observed in the AsPC-1 cells when stimulated by each anticancer agent. In response to JAK2 inhibitor treatment, PD-L1 upregulation induced by the anticancer agents was reduced in a dose-dependent manner. These results suggest that i) the JAK2/STAT1 pathway is involved in the anticancer agent-mediated PD-L1 transcription; and ii) the anticancer agents altered the tumor immune response which may induce tumor immune escape. These findings can have an influence on the design of treatments that combine chemotherapy and immunotherapy.

The amino acid-rich elemental diet Elental® preserves lean body mass during chemo- or chemoradiotherapy for esophageal cancer.

Chemo (chemoradio) therapy can induce oral mucositis and change body composition in patients with esophageal cancer. The impact of the amino acid-rich elemental diet Elental® on oral mucositis and changes in body composition during chemo (chemoradio) therapy is unclear. Thus, the purpose of the present study was to examine the preventive effects of Elental on oral mucositis and sarcopenia progression during chemo (chemoradio) therapy for esophageal cancer. Patients were randomized to receive either azulene oral rinse (Arm 1) or Elental (Arm 2) during the treatment cycle (4 weeks). The incidence of oral mucositis and other adverse events was evaluated weekly. Body composition pre- and post-treatment cycle was measured by bioelectric impedance analysis. Thirty­three patients (17 azulene and 16 Elental) completed the study, and the groups were well matched. Elental tended to reduce the incidence of oral mucositis (Arm 1, 23.5% and Arm 2, 12.5%), but there was no statistically significant difference between the groups. The average body mass index (BMI) and body fat mass decreased significantly in both groups after the treatments. Lean body mass (LBM) was reduced in Arm 1, but was increased in Arm 2 after the treatment; the relative change of LBM after the treatment was significant between Arm 1 and Arm 2 (P=0.007). This study revealed that Elental nutrition could counteract sarcopenia development during chemoradiotherapy for esophageal cancer. These properties may lead to improvement of the quality of life and clinical outcome of esophageal cancer patients treated with chemo (chemoradio) therapy (Clinical Trial Registry ID: UMIN 000007960).

Phase I clinical trial of autologous NK cell therapy using novel expansion method in patients with advanced digestive cancer.

BACKGROUND: NK cells can destroy tumor cells without prior sensitization or immunization. Tumors often lose expression of MHC molecules and/or antigens. However, NK cells can lyse tumor cells in a non-MHC-restricted manner and independent of the expression of tumor-associated antigens. NK cells are therefore considered ideal for adoptive cancer immunotherapy; however the difficulty of obtaining large numbers of fully functional NK cells that are safe to administer deters its clinical use. This phase I clinical trial seeks to address this obstacle by first developing a novel system that expands large numbers of highly activated clinical grade NK cells, and second, determining if these cells are safe in a mono-treatment so they can be combined with other reagents in the next round of clinical trials. METHODS: Patients with unresectable, locally advanced and/or metastatic digestive cancer who did not succeed with standard therapy were enrolled. NK cells were expanded ex vivo by stimulating PBMCs with OK432, IL-2, and modified FN-CH296 induced T cells. Patients were administered autologous natural killer cell three times weekly via intravenous infusions in a dose-escalating manner (dose 0.5 × 10(9), 1.0 × 10(9), 2.0 × 10(9) cells/injection, three patients/one cohort). RESULTS: Total cell population had a median expansion of 586-fold (range 95-1102), with a significantly pure (90.96 %) NK cell population. Consequently, NK cells were expanded to approximately 4720-fold (range 1372-14,116) with cells being highly lytic in vitro and strongly expressing functional markers such as NKG2D and CD16. This NK cell therapy was very well tolerated with no severe adverse events. Although no clinical responses were observed, cytotoxicity of peripheral blood was elevated approximately twofolds up to 4 weeks post the last transfer. CONCLUSION: We successfully generated large numbers of activated NK cells from small quantities of blood without prior purification of the cells. We also determined that the expanded cells were safe to administer in a monotherapy and are suitable for the next round of clinical trials where their efficacy will be tested combined with other reagents. TRIAL REGISTRATION: UMIN UMIN000007527.

Tumor inoculation site affects the development of cancer cachexia and muscle wasting.

The phenotype and severity of cancer cachexia differ among tumor types and metastatic site in individual patients. In this study, we evaluated if differences in tumor microenvironment would affect the development of cancer cachexia in a murine model, and demonstrated that body weight, adipose tissue and gastrocnemius muscle decreased in tumor-bearing mice. Interestingly, a reduction in heart weight was observed in the intraperitoneal tumor group but not in the subcutaneous group. We evaluated 23 circulating cytokines and members of the TGF-ß family, and found that levels of IL-6, TNF-α and activin A increased in both groups of tumor-bearing mice. Eotaxin and G-CSF levels in the intraperitoneal tumor group were higher than in the subcutaneous group. Atrogin 1 and MuRF1 mRNA expressions in the gastrocnemius muscle increased significantly in both groups of tumor-bearing mice, however, in the myocardium, expression of these mRNAs increased in the intraperitoneal group but not in subcutaneous group. Based on these results, we believe that differences in microenvironment where tumor cells develop can affect the progression and phenotype of cancer cachexia through alterations in various circulating factors derived from the tumor microenvironment.

Cytotoxic T lymphocyte-associated antigen 4 inhibition increases the antitumor activity of adoptive T-cell therapy when carried out with naïve rather than differentiated T cells.

Although treatment with an antibody against cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) combined with multiple therapeutic interventions has been explored, the effect of combination therapy with CTLA-4 inhibition and adoptive T-cell therapy has not been determined. In the present study, our aim was to determine whether CTLA-4 inhibition, combined with adoptive transfer of T cells at different stages of differentiation, exhibits synergistic antitumor effects in a murine colon cancer model. Mice bearing subcutaneous tumors were administered adoptive T-cell transfer of CD62Lhigh or CD62Llow cells combined with an anti-CTLA-4 antibody (α-CTLA-4) or control immunoglobulin G. Subcutaneous tumors were harvested, and the antitumor effects and helper T-cell polarization were analyzed. CTLA-4 inhibition combined with CD62Lhigh cell administration showed the strongest antitumor effect. Combination therapy increased the number of CD3+ cells within the tumor. Moreover, CTLA-4 inhibition induced polarization of T cells infiltrating the tumor toward the T helper 1 lineage, and suppressed the frequency of regulatory T cells within the tumor, particularly in combination with CD62Lhigh T-cell transfer. This is the first report demonstrating that the efficacy of α-CTLA-4 and adoptive T-cell transfer combination therapy depends on the state of differentiation of the transferred T cells. Our data support the notion that a combination of α-CTLA-4 and adoptive T-cell transfer containing an abundance of naïve phenotype cells could potentially exert antitumor effects in a clinical setting.

The inhibitory effect of heat treatment against epithelial-mesenchymal transition (EMT) in human pancreatic adenocarcinoma cell lines.

Epithelial-mesenchymal transition (EMT) plays a crucial role in cancer metastasis. In this study, we evaluated the effect of heat treatment on tumor growth factor-ß1 (TGF-ß1)-induced EMT in pancreatic cancer cells and tried to ascertain the mechanism related to any observed effects. Human pancreatic cancer cell lines (BxPC-3, PANC-1 and MIAPaCa-2) were stimulated by TGF-ß1, and evaluated for morphological changes using immunofluorescence and EMT-related factors (i.e., E-cadherin, Vimentin, Snail or ZEB-1) using RT-PCR. To examine the effect of heat on EMT, the cancer cells were heat-treated at 43°C for 1 h then stimulated with TGF-ß1. We then evaluated whether or not heat treatment changed the expression of EMT-related factors and cell migration and also whether Smad activation was inhibited in TGF-ß signaling. After being treated with TGF-ß1, pancreatic cancer cells resulted in EMT and cell migration was enhanced. Heat treatment inhibited TGF-ß1-induced changes in morphology, inhibited the expression of EMT-related factors, and attenuated TGF-ß1-induced migration in pancreatic cancer cells. Additionally, we observed that heat treatment blocked TGF-ß1-induced phosphorylation of Smad2 in PANC-1 cells. Our results suggest that heat treatment can suppress TGF-ß1-induced EMT and opens the possibility of a new therapeutic use of hyperthermia as a potential treatment for cancer metastasis.

Phase I clinical trial of fibronectin CH296-stimulated T cell therapy in patients with advanced cancer.

BACKGROUND: Previous studies have demonstrated that less-differentiated T cells are ideal for adoptive T cell transfer therapy (ACT) and that fibronectin CH296 (FN-CH296) together with anti-CD3 resulted in cultured cells that contain higher amounts of less-differentiated T cells. In this phase I clinical trial, we build on these prior results by assessing the safety and efficacy of FN-CH296 stimulated T cell therapy in patients with advanced cancer. METHODS: Patients underwent fibronectin CH296-stimulated T cell therapy up to six times every two weeks and the safety and antitumor activity of the ACT were assessed. In order to determine immune function, whole blood cytokine levels and the number of peripheral regulatory T cells were analyzed prior to ACT and during the follow up. RESULTS: Transferred cells contained numerous less-differentiated T cells greatly represented by CD27+CD45RA+ or CD28+CD45RA+ cell, which accounted for approximately 65% and 70% of the total, respectively. No ACT related severe or unexpected toxicities were observed. The response rate among patients was 22.2% and the disease control rate was 66.7%. CONCLUSIONS: The results obtained in this phase I trial, indicate that FN-CH296 stimulated T cell therapy was very well tolerated with a level of efficacy that is quite promising. We also surmise that expanding T cell using CH296 is a method that can be applied to other T- cell-based therapies. TRIAL REGISTRATION: UMIN UMIN000001835.

Analysis of cardiopulmonary stress during endoscopy: is unsedated transnasal esophagogastroduodenoscopy appropriate for elderly patients?

BACKGROUND: Transnasal esophagogastroduodenoscopy (EGD) without sedation has been reported to be safe and tolerable. It has recently been used widely in Japan for the detection of upper gastrointestinal disease. Alternatively, transoral examination using a thin endoscope has also been reported to be highly tolerable. OBJECTIVE: To examine the cardiocirculatory effects of transoral versus transnasal EGD in an attempt to determine the most suitable endoscopic methods for patients ≥75 years of age. METHODS: Subjects who underwent monitoring of respiratory and circulatory dynamics without sedation during endoscopic screening examinations were enrolled at the New Ooe Hospital (Kyoto, Japan) between April 2008 and March 2009. A total of 165 patients (age ≥75 years) provided written informed consent and were investigated in the present study. Patients were randomly divided into three subgroups: UO group--thin endoscope; SO group--standard endoscope; and UT group--transnasal EGD. Percutaneous arterial blood oxygen saturation, heart rate and blood pressure were evaluated just before EGD and at five time points during EGD. After transnasal EGD, patients who had previously been examined using transoral EGD with a standard endoscope were asked about preferences for their next examination. RESULTS: There were no statistical differences in the characteristics among the groups. Percutaneous oxygen saturation in the UT group showed a transient drop compared with the SO and UO groups at the beginning of the endoscopic procedure. Heart rate showed no significant differences among the SO, UO and UT groups; Systolic blood pressure in the UO group was lower immediately after insertion compared with the SO and UT groups. The rate pressure product in the UO group was comparable with that in the UT group during endoscopy, and the SO group showed a continuously higher level than the UO and UT groups. More than one-half (54.4%) of patients were 'willing to choose transnasal EGD for next examination'. CONCLUSIONS: For elderly patients, unsedated transnasal EGD failed to show an advantage over unsedated standard endoscopy. Transoral thin EGD was estimated to be safe and tolerable.

Anoxia/reoxygenation induces epithelial-mesenchymal transition in human colon cancer cell lines.

Epithelial-mesenchymal transition (EMT) is considered to be a crucial event in the development of cancer metastasis. Anoxia/reoxygenation (A/R) is known to occur in cancer tissues due to angiogenesis and changes in tissue pressure that occur during tumor growth. We investigated whether A/R induces EMT in the human colon cancer cell line HT-29. Colon cancer cells were exposed to anoxia (2 h) followed by reoxygenation (4-22 h) and evaluated for EMT changes using immunofluorescence and western blot analyses. We also investigated the expression of EMT-related transcription factors (Snail and ZEB1) using RT-PCR and evaluated the expression of NF-κB using ELISA. To determine whether NF-κB is involved in A/R-induced EMT, HT-29 cells were treated with proteasome inhibitors. Colon cancer cells exposed to A/R underwent EMT morphological changes; the cancer cells acquired a spindle-shaped phenotype. The expression of E-cadherin on the cell surface and the total amount of E-cadherin proteins were reduced after A/R. The expression of EMT-related transcription factors (Snail, ZEB1) was increased after A/R. Pretreatment with proteasome inhibitors significantly attenuated the downregulation of E-cadherin induced by A/R. These results indicate that A/R induces EMT in human colon cancer cells through an NF-κB-dependent transcriptional pathway.

Whole blood interferon-γ levels predict the therapeutic effects of adoptive T-cell therapy in patients with advanced pancreatic cancer.

A core challenge in administering immune-based treatments for cancer is the establishment of easily accessible immunological assays that can predict patients' clinical responses to immunotherapy. In this study, our aim was to predict the therapeutic effects of adoptive T-cell therapy in patients with advanced pancreatic cancer. To do this, we evaluated whole blood cytokine levels and peripheral regulatory T cells (Tregs) in 46 patients with unresectable or recurrent pancreatic cancer who received adoptive T-cell therapy at 2-week intervals. To test immune function, venous blood was obtained from patients before the start of therapy and 2 weeks after the 4th treatment. Whole blood interferon (IFN)-α levels (after stimulation with the Sendai virus) were evaluated, as well as the levels of 9 cytokines stimulated with phytohemagglutinin [interleukin (IL)-2, IL-4, IL-5, IL-10, IL-12(p70), IL-13, tumor necrosis factor-α, IFN-γ, and granulocyte-monocyte colony-stimulating factor]. Peripheral Tregs were analyzed by flow cytometry. Using the obtained data, we then observed the relationship between these immunological parameters and clinical outcome of patients. We found that the whole blood production of IFN-γ, IL-2, IL-4, IL-5 and IL-13 significantly increased after adoptive T-cell therapy, whereas the number of peripheral Tregs did not change. Multivariate Cox proportional hazards analyses indicated that the number of peripheral Tregs before receiving adoptive T-cell therapy and the change in IFN-γ levels after adoptive T-cell therapy were independent variables predicting overall survival. The findings of this study indicate that the assay of whole blood IFN-γ production offers promise for evaluating the clinical response of patients to cancer immunotherapy.

Phase II trial of combined regional hyperthermia and gemcitabine for locally advanced or metastatic pancreatic cancer.

PURPOSE: Despite advances in cancer therapy, treating pancreatic cancer remains one of the major challenges in the field of medical oncology. We conducted this phase II study to evaluate the efficacy and safety of regional hyperthermia combined with gemcitabine for the treatment of unresectable advanced pancreatic cancer. METHODS: Eligibility criteria included histologically proven, locally advanced or metastatic pancreatic cancer. Gemcitabine was administered intravenously at a dose of 1000 mg/m(2) on days 1, 8, and 15 every 4 weeks. Regional hyperthermia was performed once weekly, 1 day preceding or following gemcitabine administration. The primary end point was the 1-year survival rate. Secondary objectives were determination of tumour response and safety. RESULTS: We enrolled 18 patients with advanced pancreatic cancer between November 2008 and May 2010. The major grade 3-4 adverse events were neutropenia and anaemia; however, there were no episodes of infection. The objective response rate (ORR) and disease control rate (ORR + stable disease) were 11.1% and 61.1%, respectively. Median overall survival (OS) was 8 months, and the 1-year survival rate was 33.3%. Median OS of patients with locally advanced pancreatic cancer was 17.7 months. CONCLUSIONS: Regional hyperthermia combined with gemcitabine is well tolerated and active in patients with locally advanced pancreatic cancer.

Relationship between circulating cytokine levels and physical or psychological functioning in patients with advanced cancer.

OBJECTIVE: To investigate the relation between functional impairments of cancer patients and circulating cytokines using a multiplex technique. DESIGN AND METHODS: 50 patients with cancer were assessed using the quality of life (QOL) questionnaire. 27 plasma cytokine levels were determined by using the Bio-Plex array system. The relation to QOL scores was assessed using Chi-square test for categorical variables and univariate linear regression analysis for cytokine levels. RESULTS: Multivariate analysis showed that interleukin-6 (IL-6) level is a significant independent determinant of physical (ß=-0.238, P=0.0126) and cognitive functioning (ß=-0.462, P=0.0006) and that vascular endothelial growth factor (VEGF) level is a significant independent determinant of emotional functioning (ß=-0.414, P=0.039). CONCLUSION: This study, in which 27 cytokines are simultaneously tested with cutting edge technology, demonstrates that plasma IL-6 and VEGF are significant independent determinants of functional impairments in patients with cancer.

Adoptive cellular therapy enhances the helper T cell response and reduces the number of regulatory T cells.

It remains to be clarified whether adoptive cellular therapy (ACT) in patients with advanced cancer, in whom strong immunosuppression and immune-escape mechanisms are established, has the potential to alter cytokine secretion from blood cells and affect the number of regulatory T cells (Tregs). In this study, the secretion of cytokines from peripheral blood cells and the number of peripheral blood Tregs were analyzed before and after ACT. Blood samples were collected from 109 consecutive cancer patients who received ACT, which consisted of anti-CD3 stimulated lymphokine-activated killer cells. For testing immune function, venous blood was obtained from patients before the start of therapy and after they had received 4 cycles of ACT. Of the 109 patients, 76 received ACT four times or more. All 109 blood samples at baseline and 76 follow-up samples were available. The secretion ability of various cytokines from peripheral blood cells was measured, as well as the number of peripheral blood Tregs. We found that the secretion ability of interferon (IFN)-γ and tumor necrosis factor (TNF)-α was enhanced significantly after treatment, while the number of Tregs and the ratio of Treg to CD4 was significantly decreased. Overall survival in patients with increased IFN-γ and TNF-α secretion after ACT was significantly longer. These findings suggest a potential therapeutic role for ACT in cancer immunotherapy.

Decrease of the regulatory T-cell population by adoptive T-cell transfer in a mouse colorectal cancer transplant model.

We examined the effects of adoptive T-cell transfer (ACT) on the population of regulatory T cells (Tregs) in a mouse colorectal cancer transplant model. In an in vivo study, Treg populations in Balb/c mice colon26 transplant model after ACT were analyzed in peripheral blood, local lymph node, and tumor. In an in vitro study CD4+ cells were cultured in medium containing TGF-beta to induce Tregs. LAK cells were added or not in this Treg induction system. Treg induction after coculture with LAK was investigated. We also studied the role of IFN-gamma in the mechanism of Treg induction. Tregs in the draining lymph nodes and tumor were significantly suppressed by ACT. The induction of Tregs in vitro was inhibited by coculture with LAK cells. Furthermore, Tregs in the cultured cells were significantly inhibited by addition of exogenous IFN-gamma. Moreover, Tregs were increased by addition of IFN-gamma mAb. ACT may decrease Tregs in tumor-bearing hosts. One of the mechanisms is considered to be IFN-gamma inhibiting the induction of Tregs.

Preparation of core-shell-structured nanoparticles (with a noble-metal or metal oxide core and a chromia shell) and their application in water splitting by means of visible light.

Core-shell-structured nanoparticles, consisting of a noble metal or metal oxide core and a chromia (Cr(2)O(3)) shell, were studied as promoters for photocatalytic water splitting under visible light. Core nanoparticles were loaded by impregnation, adsorption or photodeposition onto a solid solution of gallium nitride and zinc oxide (abbreviated GaN:ZnO), which is a particulate semiconductor photocatalyst with a band gap of approximately 2.7 eV, and a Cr(2)O(3) shell was formed by photodeposition using a K(2)CrO(4) precursor. Photodeposition of Cr(2)O(3) on GaN:ZnO modified with a noble metal (Rh, Pd and Pt) or metal oxide (NiO(x), RuO(2) and Rh(2)O(3)) co-catalyst resulted in enhanced photocatalytic activity for overall water splitting under visible light (lambda>400 nm). This enhancement in activity was primarily due to the suppression of undesirable reverse reactions (H(2)-O(2) recombination and/or O(2) photoreduction) and/or protection of the core component from chemical corrosion, depending on the core type. Among the core materials examined, Rh species exhibited relatively high performance for this application. The activity for visible-light water splitting on GaN:ZnO modified with an Rh/Cr(2)O(3) core-shell configuration was dependent on both the dispersion of Rh nanoparticles and the valence state. In addition, the morphology of the Cr(2)O(3) photodeposits was significantly affected by the valence state of Rh and the pH at which the photoreduction of K(2)CrO(4) was conducted. When a sufficient amount of K(2)CrO(4) was used as the precursor and the solution pH ranged from 3 to 7.5, Cr(2)O(3) was successfully formed with a constant shell thickness (approximately 2 nm) on metallic Rh nanoparticles, which resulted in an effective promoter for overall water splitting.