Biomedical subjects

Akira Tasaki

Publications and source records attributed to Akira Tasaki.

13 recordsLinked to original sources

PubMed2005

Effects of docetaxel on antigen presentation-related functions of human monocyte-derived dendritic cells.

PURPOSE: Docetaxel (TXT) is a unique chemotherapeutic agent that has been approved for treating various types of malignancies. TXT stabilizes microtubule assembly in cells and causes various dysfunctions of microtubule-dependent cellular events. Patients with advanced malignancies are beginning to receive TXT in combination with immunotherapy; however, the influence of TXT at clinically achievable serum concentrations (less than 10(-6) M) on antigen presentation-related functions of human monocyte-derived dendritic cells (Mo-DCs) remains unclear. METHODS: Immature Mo-DCs (imMo-DCs) were generated from peripheral blood monocytes with interleukin-4 and granulocyte-macrophage colony-stimulating factor in vitro. Mature Mo-DCs (mMo-DCs) were induced from imMo-DCs with tumor necrosis factor-alpha and prostaglandin E(2). RESULTS: TXT at concentrations lower than 10(-7) M did not significantly affect cellular viability, phagocytosis, or expression of antigen presentation-related molecules of Mo-DCs. In contrast, TXT at concentrations lower than 10(-9) M significantly suppressed directional motility of imMo-DCs toward MIP-1alpha and of mMo-DCs toward MIP-3beta. However, TXT had no effect on either CCR1 expression by imMo-DCs or CCR7 expression by mMo-DCs. No gross changes in the microtubule skeleton were evident by immunofluorescence microscopy after treatment with TXT at less than 10(-8) M. However, reduced numbers of imMo-DCs with podosomes localized primarily in one cell region were observed. CONCLUSIONS: The present results indicate that different concentrations of TXT influence antigen presentation-related functions differently. In particular, TXT at relatively low therapeutic doses disrupts chemotactic motility of Mo-DCs.

Antineoplastic Agents, Phytogenic↗

PubMed2005

Lung volume reduction surgery for a professional athlete with Swyer-James syndrome.

Swyer-James syndrome is an uncommon, emphysematous disease characterized by roentgenographic hyperlucency of one lung or lobe due to loss of the pulmonary vascular structure and to alveolar overdistension. We here describe a 28-year-old professional bicycle racer with Swyer-James syndrome who had dyspnea on exertion, especially during a bicycle race. Lung volume reduction surgery was performed with video-assisted thoracoscopic surgery. This treatment improved his pulmonary function, and he is active as a bicycle racer now.

Adult↗

PubMed2004

Paclitaxel probably enhances cytotoxicity of natural killer cells against breast carcinoma cells by increasing perforin production.

Paclitaxel, a semisynthetic taxane, is one of the most active chemotherapeutic agents for the treatment of patients with breast cancer. We focused on the effect of paclitaxel on the cytotoxicity of natural killer (NK) cells. NK cells were purified by negative selection with magnetic beads from peripheral blood mononuclear cells of healthy volunteers. A human breast carcinoma cell line BT-474 and an NK cell-sensitive erythroleukemia cell line K562 were used as targets. Cytotoxicity of NK cells was determined by 51Cr-release assay with labeled target cells. Paclitaxel (1-100 nM) did not affect cellular viability, and significantly enhanced cytotoxicity of NK cells in a dose-dependent manner. Although paclitaxel did not affect Fas-ligand expression of NK cells, paclitaxel induced mRNA and protein production of perforin, an effector molecule in NK cell-mediated cytotoxicity. Concanamycin A, a potent inhibitor of the perforin-mediated cytotoxic pathway, inhibited paclitaxel-dependent NK cell-mediated cytotoxicity. Furthermore, paclitaxel induced activation of nuclear factor kappa B (NF-kappa B) in NK cells. NF-kappa B inhibitor pyrrolidine dithiocarbamate significantly suppressed both paclitaxel-induced perforin expression and NK cell cytotoxicity. Our results show for the first time that paclitaxel enhances in vitro cytotoxicity of human NK cells. Moreover, our results suggest a significant association between enhanced NK cell cytotoxicity, increased perforin production, and NF-kappa B activation.

Adenocarcinoma↗

PubMed2004

Hedgehog signaling pathway is a new therapeutic target for patients with breast cancer.

The Hedgehog (Hh) signaling pathway functions as an organizer in embryonic development. Genetic analysis has demonstrated a critical role for the Hh pathway in mammary gland morphogenesis. Disruption of Patched1, a component of the Hh pathway, results in abnormal growth of mammary duct. Recent studies have shown constitutive activation of the Hh pathway in various types of malignancies. However, it remains unclear whether this pathway is activated in human breast cancer. Here, we determined the expression of the components, including Sonic Hh, Patched1, and Gli1, of the Hh pathway by immunohistochemical staining in a series of 52 human breast carcinomas. All of 52 tumors display staining of high intensity for Gli1 when compared with adjacent normal tissue. The nuclear staining ratio of Gli1 correlates with expression of estrogen receptor and histologic type. Exposure to cyclopamine, a steroidal alkaloid that blocks the Hh pathway, suppresses expression of Gli1 and the growth of the Hh pathway-activated breast carcinoma cells. These data indicate that the Hh pathway is a new candidate for therapeutic target of breast cancer.

Adult↗

PubMed2004

Interleukin 1beta enhances invasive ability of gastric carcinoma through nuclear factor-kappaB activation.

PURPOSE: We examined the role of interleukin (IL)-1beta in activation of nuclear factor kappaB (NF-kappaB) and the biological function of activated NF-kappaB in gastric carcinoma cells. EXPERIMENTAL DESIGN: Human gastric carcinoma cell line GCTM-1 was used to examine NF-kappaB activation by immunostaining and electrophoretic mobility shift assay. Matrix metalloproteinase (MMP)-9 expression, which plays an important role in tumor invasion, was assessed by semiquantitative reverse transcription-PCR, Western blotting, and immunostaining. The invasive ability of GCTM-1 cells was measured by Matrigel invasion assay. In vivo expression of IL-1beta and MMP-9 and activation of NF-kappaB in 10 surgically resected gastric carcinoma specimens were examined immunohistochemically. RESULTS: IL-1beta enhanced NF-kappaB activation, MMP-9 expression, and the invasive ability of GCTM-1. A NF-kappaB inhibitor, pyrrolidine dithiocarbamate, suppressed both MMP-9 expression and invasiveness of IL-1beta-treated GCTM-1 cells. IL-1beta did not increase the invasive ability of GCTM-1 cells transfected with MMP-9 antisense oligonucleotide. Concomitant expression of IL-1beta and nuclear NF-kappaB was observed in 3 of 10 gastric carcinoma specimens. Cells producing IL-1beta were tumor-infiltrating macrophages in two specimens and gastric carcinoma cells in one specimen. CONCLUSIONS: One of the molecules that may play a role in NF-kappaB activation in some gastric carcinomas is IL-1beta. The present results suggest that IL-1beta increases the invasive ability of carcinoma cells through activation of NF-kappaB and the resulting MMP-9 expression.

Base Sequence↗

PubMed2004

Three-dimensional two-layer collagen matrix gel culture model for evaluating complex biological functions of monocyte-derived dendritic cells.

Dendritic cell-like cells (Mo-DCs) generated from peripheral blood monocytes with interleukin-4 (IL-4) and granulocyte-macrophage colony-stimulating factor (GM-CSF) have been used as tools to treat cancer patients (DC-vaccines). Because Mo-DCs have multiple antigen presentation-related functions, including phagocytosis, migration, cytokine production, and T cell stimulation, establishment of a method for simultaneously evaluating the various functions of Mo-DCs is important. We developed a new in vitro three-dimensional two-layer collagen matrix culture model that consists of a collagen gel containing Mo-DCs as the lower layer and a collagen gel containing necrotic GCTM-1 tumor cells and/or T cells as the upper layer. We used this system to observe simultaneously multiple functions of Mo-DCs by phase-contrast or fluorescence microscopy and to assess IL-12 secretion during more than 2 weeks of culture. We also observed interactions between Mo-DCs and necrotic GCTM-1 or T cells on an individual cell basis by time-lapse videomicroscopy. In addition, we collected Mo-DCs from the collagen gels by collagenase treatment and analyzed the expression of antigen presentation-related molecules such as HLA-DR, CD80, CD83, and CD86 on Mo-DCs. This model may be a useful tool for evaluation of the various functions of Mo-DCs used as DC vaccines and for studies of the complex behaviors of Mo-DCs in vivo.

Antigen Presentation↗

PubMed2003

Dendritic cell-based combined immunotherapy with autologous tumor-pulsed dendritic cell vaccine and activated T cells for cancer patients: rationale, current progress, and perspectives.

Effective adoptive cancer immunotherapy depends on an ability to generate tumor-antigen-presenting cells and tumor-reactive effector lymphocytes and to deliver these effector cells to the tumor. Dendritic cells (DCs) are the most potent antigen-presenting cells, capable of sensitizing T cells to new and recall antigens. Many studies have shown that tumors express unique proteins that can be loaded on DCs to trigger an immune response. The current experimental and clinical statuses of adoptive transfer of tumor antigen-pulsed DCs and vaccine-primed activated T cells are summarized herein. Clinical trials of antigen-pulsed DCs have been conducted in patients with various types of cancer, including non-Hodgkin lymphoma, multiple myeloma, prostate cancer, renal cell carcinoma, malignant melanoma, colorectal cancer, and non-small cell lung cancer. These studies have shown that antigen-loaded DC vaccination is safe and promising for the treatment of cancer. In addition, tumor vaccine-primed T cells have been shown to induce antitumor activity in vivo. Several clinical studies are being conducted on the use of vaccine-primed T cells such as tumor-drainage lymph node. It is reasonable to consider using both tumor antigen-pulsed DCs and vaccine-primed lymphocytes as adjuvants. We are now investigating the use of autologous whole tumor antigen-pulsed DCs and the DC vaccine-primed activated lymphocytes in patients with multiple metastasis of solid tumors.

Antigens, Neoplasm↗

PubMedDate not supplied

Combination of adoptive immunotherapy with Herceptin for patients with HER2-expressing breast cancer.

Clinical use of Herceptin (trastuzumab), which is a humanized monoclonal antibody against HER2, started for patients with HER2-overexpressing breast cancer. To potentiate the efficacy of the Herceptin therapy, this study focused on the combination of Herceptin with activated immune lymphocytes. We used peripheral blood mononuclear cells (PBMCs) as effector cells and used HER2-unexpressing K562 cells, HER2-weakly-expressing breast carcinoma cells (Breast-M), or HER2-strongly-expressing breast carcinoma cells (BT-474) as target cells. Interleukin-2 (IL-2)-activated PBMCs, IL-2/OKT-3-activated PBMCs and a streptococcal preparation OK-432-activated PBMCs were generated and used as effector cells. Cytotoxic activity was determined with 4-hour 51Cr release assay. Both fresh PBMCs and activated PBMCs exhibited Herceptin-dependent cytotoxicity. Importantly, Herceptin-dependent cytotoxicity was found even at a lower effector to target cell ratio (E/T ratio) than that of Herceptin-independent cytotoxicity. In addition, Herceptin-dependent cytotoxicity by these activated PBMCs was observed even in HER2-weakly-expressing Breast-M cells. Since gamma-globulin or anti-CD16 antibody abrogated Herceptin-dependent cytotoxicity, it seems likely that antibody-dependent cellular cytotoxicity (ADCC) plays an important role in the Herceptin-dependent cytotoxicity. We present a recurrent breast cancer patient with malignant pleural effusion, in which HER2-strongly-expressing tumor cells were present, who was undergoing Herceptin therapy. Cluster formation between tumor cells and intrapleural mononuclear cells was induced 24 hours after intravenous injection of Herceptin (4 mg/kg). Mononuclear cells bound specifically to HER2-strongly-expressing tumor cells but not to other cells, such as mesothelial cells, suggested a Herceptin-mediated binding like ADCC in vivo. Taken together, these findings suggest that the combination of Herceptin with various types of activated lymphocytes may be a new therapeutic strategy, not only for HER2-strongly-expressing breast cancer but also for HER2-weakly-expressing cancer.

Adenocarcinoma↗

PubMedDate not supplied

Combined immunotherapy with intracavital injection of activated lymphocytes, monocyte-derived dendritic cells and low-dose OK-432 in patients with malignant effusion.

We have conducted a pilot study with combined immunotherapy using autologous lymphocytes activated ex vivo and monocyte-derived dendritic cells in combination with low-dose OK-432, a streptococcal preparation, in five patients with peritoneal or pleural carcinomatosis who were resistant to standard chemotherapy. All patients were given 3 to 10 courses of the combined immunotherapy. No severe adverse reactions occurred. Effusion production was decreased in all of the patients. Significant decreases in tumor markers of both effusions and sera as well as effusion volume occurred in all of the patients. Cytological examinations revealed a marked decrease or disappearance of cancer cells in those effusions. Three patients showed increase in IFN-gamma levels in the effusions. The overall prognosis of the patients was acceptable and the mean survival time was more than 9 months. The locoregional immunotherapy seems to be encouraging in view of therapeutic modality in patients who are resistant to standard chemotherapy. Our study provides a new protocol for immunotherapy and warrants further phase I/II clinical study for chemo-resistant patients with malignant effusion.

Adult↗

PubMedDate not supplied

Nuclear factor-kappaB p65 is a prognostic indicator in gastric carcinoma.

BACKGROUND: In common with other investigators, we have reported the constitutive activation of transcription factor nuclear factor-kappaB (NF-kappaB) in a variety of carcinomas, but there is no definite information on its clinical significance. MATERIALS AND METHODS: NF-kappaB p65 activation was determined by immunohistochemical analysis of surgically resected specimens from 63 gastric carcinomas. The 63 patients were divided into a high NF-kappaB group (21 patients) and a low NF-kappaB group (42 patients). Forty-seven of the 63 patients underwent curative resection. The 47 patients consisted of 13 high NF-kappaB patients and 34 low NF-kappaB patients. RESULTS: The high NF-kappaB group demonstrated a shorter overall survival rate compared with the low NF-kappaB group (p=0.015). In the 47 patients who underwent curative resection, the high NF-kappaB group also showed a poor survival prognosis (p=0.032). Multivariate analysis indicated that NF-kappaB activation is a potential prognostic factor in gastric carcinoma. CONCLUSION: Constitutive activation of NF-kappaB p65 may be a new prognostic parameter in gastric carcinoma.

Aged↗

PubMedDate not supplied

Immunohistochemical staining of hedgehog pathway-related proteins in human thymomas.

The thymus plays an essential role in the maturing of progenitor cells to functional T cells. Recent studies suggest that the Hedgehog (Hh) signaling pathway contributes to this differentiation process. However, there is limited information concerning the expression of Hh pathway-related proteins (Hh proteins) in the human thymus. The staining of Hh proteins in the thymic epithelium of 26 surgically resected thymoma tissues was examined by immunohistochemistry. The staining of sonic Hh (Shh) correlated relatively well with the World Health Organization histological classification of thymoma. The higher the grade, the fainter the staining. However, no significant difference in Shh staining was found between normal and neoplastic epithelia. Interestingly, Gli1 staining in thymomas was significantly greater than that in normal thymus (p < 0.0001). Thus, some members of the Hh signaling pathway may contribute to the development of thymoma.

Adult↗

PubMedDate not supplied

Purification, characterization and biological significance of tumor-derived exosomes.

Exosomes are nanovesicles that are released into the extracellular environment during the fusion of multivesicular bodies with the plasma membrane. Exosomes released from dendritic cells, dexosomes, have several biological functions, for example as immunostimulants. Some tumor cells also secrete exosomes (Tu-exosomes). Although experimental data obtained with the use of dexosomes suggest a biological function of Tu-exosomes, this still remains poorly understood. To examine the function of Tu-exosomes, we established a method for collecting highly purified Tu-exosomes, using paramagnetic beads coated with antibodies against tumor-specific proteins such as HER2/neu. With these antibody-coated beads (Ab-beads), it was possible to collect HER2-expressing Tu-exosomes of high purity. Tu-exosomes were also collected from malignant ascites, which contain exosomes secreted from various types of cells such as tumor cells, lymphoid cells and mesothelial cells. The isolation of Tu-exosomes was confirmed by FACS analysis. With regard to their biological functions, Tu-exosomes cultured with a human breast cancer cell line bound to the cell surface and increased tumor cell proliferation. These data indicate that Tu-exosomes may have physiological functions.

Adenocarcinoma↗

PubMedDate not supplied

Combination therapy with tumor cell-pulsed dendritic cells and activated lymphocytes for patients with disseminated carcinomas.

This phase I study was performed to assess the safety and immune response of tumor cell-pulsed dendritic cell (DC) vaccine therapy against cancer patients with multiple metastases. DCs, generated from adherent cells of peripheral blood mononuclear cells (PBMCs) using interleukin-4 (IL-4) and granulocyte/monocyte colony-stimulating factor, were loaded with autologous necrotic whole tumor cells. Thereafter, the DCs were matured with culture supernatants of OK-432-stimulated PBMCs. Activated lymphocytes were also induced from non-adherent cells of PBMCs using OKT-3 and IL-2. Patients received a subcutaneous injection of DCs loaded with tumor cells every 2 weeks and received an intravenous injection of activated lymphocytes every 4 weeks. This combination therapy was named tumor-pulsed DC vaccine therapy. Tumor-pulsed DC vaccine therapy was continued as long as possible in 19 patients. No particular adverse reactions, except for low-grade fever, were found. The patients could be divided into two groups according to the survival time, i.e., 6 responders (long survival patients) and 13 non-responders (short survival patients). Based on the laboratory data of responders, eligibility criteria were determined. Using the eligibility criteria, a phase I/II study was recently performed with 15 patients. A delayed-type hypersensitivity reaction against tumor-pulsed DCs became positive in 13 of the 15 patients within 6 months after the therapy. This therapy was again safe, and no evidence of autoimmune disease was noted. The survival time of these 15 patients was significantly prolonged compared with that of the 13 non-responders of the phase I study (p < 0.0001). This continuous tumor-pulsed DC vaccine therapy was well tolerated in patients with disseminated carcinomas.

Adult↗