Biomedical subjects

Mitsuo Katano

Publications and source records attributed to Mitsuo Katano.

34 records · Page 2Linked to original sources

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↗

PubMed2003

Mitochondria-targeting therapeutic strategies for overcoming chemoresistance and progression of cancer.

The cytotoxic effects of many anticancer drugs are mediated via the apoptotic pathways. Chemoresistant tumor cells have acquired the ability to evade the action of multiple classes of anti-cancer drugs. One mechanism by which tumor cells survive in the presence of chemotherapy is by increasing anti-apoptotic activities. Since mitochondria are critical 'gatekeepers' to the apoptosis process, development of cytotoxic drugs that target mitochondria may provide a new strategy to induce apoptosis in tumor cells. Mitochondrial permeability transition pore complex (PTPC) controls mitochondrial membrane permeabilization, which is a critical event in the process leading to chemotherapy-induced apoptosis. Therefore, targeting of PTPC components may overcome chemoresistance in tumor cells. Moreover, alterations in mitochondrial DNA such as mutation and the subsequent dysfunction of mitochondrial respiratory enzyme have been reported in various types of cancer, and their functional consequences are associated cancer development, chemoresistance, and therapeutic implications. In this mini-review, we aim to provide a brief review on several mitochondria-targeting strategies to overcome chemoresistance in cancer.

Animals↗

PubMed2002

Identification of a novel transcriptional activator, BSAC, by a functional cloning to inhibit tumor necrosis factor-induced cell death.

Tumor necrosis factor (TNF) is a multifunctional cytokine, which induces proliferation or death in a cell type-dependent manner. We previously showed that murine embryonic fibroblasts (MEFs) from TNF receptor-associated factor 2 (Traf2) and Traf5 double-deficient (double knockout (DKO)) mice were highly susceptible to TNF-induced cell death. By functional cloning to rescue DKO MEFs from TNF-induced cell death, we have identified a novel gene, Bsac. BSAC is composed of N-terminal basic, SAP (SAF-A/B, Acinus, PIAS), and coiled-coil domains. BSAC is a nuclear protein, and overexpression of BSAC potently activates promoters containing A + T-rich sequences named CArG boxes. Domain mapping analysis revealed that both N-terminal basic and C-terminal proline-rich sequence are required for the transcriptional activity. Overexpression of BSAC in DKO MEFs partially inhibited TNF-induced cell death by suppressing activation of caspases. Interestingly, inhibition of TNF-induced cell death was not observed in DKO MEFs transfected with either N-terminal or C-terminal deletion mutant of BSAC, revealing an intimate correlation between transcriptional activity and antiapoptotic function. Recently, a human homologue of BSAC named MAL/MKL1 (megakaryocytic acute leukemia/megakaryoblastic leukemia-1) was identified as a fusion transcript generated by t(1,22) translocation in acute megakaryoblastic leukemia. Collectively, BSAC is a novel transcriptional activator with antiapoptotic function, which may be involved in the leukemogenesis.

Amino Acid Sequence↗

PubMed2002

Dysfunctional and short-lived subsets in monocyte-derived dendritic cells from patients with advanced cancer.

Dendritic cells (DCs) are antigen-presenting cells specialized for the induction of the primary T-cell response. Tumor immunotherapy using DCs loaded with tumor antigens is under way for patients with several types of advanced malignancies. In this study, DC-like cells (Mo-DCs) were generated from peripheral blood monocytes with granulocyte-macrophage colony-stimulating factor and interleukin-4. The antigen-presenting abilities, including capture of apoptotic tumor cells, IL-12 secretion, expression of antigen-presentation-related molecules (HLA-ABC, HLA-DR, and CD80), and mixed leukocyte reaction, of Mo-DCs from 37 patients with advanced cancer (pMo-DCs) were compared to those of 20 healthy volunteers (hMo-DCs). Seven days after the initial culture, no significant difference was found in either the number or the size of Mo-DC-forming colonies between the two groups. However, most of the antigen-presenting abilities of pMo-DCs were weaker than those of hMo-DCs on day 7. On day 14, both number and size of colonies were significantly decreased in pMo-DCs but not in hMo-DCs. Interestingly, the antigen-presenting abilities of the remaining pMo-DCs gradually strengthened with time and by day 14 no significant difference was observed between pMo-DCs and hMo-DCs. These results indicate that pMo-DCs contain dysfunctional and short-lived Mo-DC subsets.

Aged↗

PubMed2002

Intraperitoneal injection of adenovirus-mediated NK4 gene suppresses peritoneal dissemination of pancreatic cancer cell line AsPC-1 in nude mice.

NK4, composed of the N-terminal hairpin and subsequent four-kringle domains of hepatocyte growth factor (HGF), acts not only as a competitive antagonist for HGF but also as a potent angiogenesis inhibitor. This study was designed to assess a therapeutic potential of adenovirus-mediated NK4 gene transfer for disseminated pancreatic cancer cells in the peritoneal lavage of nude mice. We constructed a recombinant adenovirus NK4 (Ad-NK4), which encodes a secretable form of human NK4. In vitro migration of AsPC-1 (human pancreatic cancer cell line) was stimulated by HGF, and it was completely inhibited by Ad-NK4 transfection. Weekly intraperitoneal injections of Ad-NK4 could suppress the development of tumor nodules in a nude mouse peritoneal dissemination model. NK4 expression was detected in the disseminated nodules, liver, pancreas, spleen, and mesenterium. Immunohistochemical study of the disseminated tumors showed a remarkable decrease in microvessel density and an increase in number of apoptotic tumor cells in the Ad-NK4-treated mice. Survival of the Ad-NK4-treated mice was significantly improved. This study indicates that the intraperitoneal transduction of adenovirus-mediated NK4 gene may be a useful therapeutic modality to prevent the development of peritoneal dissemination of pancreatic cancer.

Adenocarcinoma↗

PubMed2002

A large quantity of CD3-/CD19-/CD16- lymphocytes in malignant pleural effusion from a patient with recurrent cholangio cell carcinoma.

Tumor infiltrating lymphocytes (TILs) are candidates for adoptive cellular immunotherapy. Here we report on a patient whose TILs presented unusual lymphocyte antigens. Pleural effusions were collected from a 47-year-old man with recurrent cholangio cell carcinoma and malignant effusion. Effusion-associated lymphocytes (EALs) were separated by Ficoll-Hypaque gradient, and the EAL phenotype was determined by flow cytometry. The percentage of positive cells was determined for each lymphocyte-related differentiation antigen. The percentages of CD3+, CD19+, and CD16+ lymphocyte subpopulations among EALs were 20%, 7%, and 3%, respectively. Nearly 70% of EALs were CD3-/CD19-/CD56-/CD16- cells. The phenotypes of peripheral blood lymphocytes (PBLs) collected simultaneously from the patient's peripheral blood were CD3+ (52%), CD19+ (20%), and CD16+ (20%). When EALs were cultured in medium without pleural effusion, T cell-related antigens, but not B cell- or natural killer (NK) cell-related antigens, were newly expressed on EALs, and this expression reached a plateau after 48 h in culture. The proportions of CD3+, CD19+, and CD16+ cells were 69%, 7%, and 3%, respectively. However, when EALs were cultured in medium with pleural effusion, increased expression of T cell-related antigens was not observed; the proportions of CD3+, CD19+, and CD16+ cells were 16%, 6%, and 1%, respectively. Neither total cell numbers nor cellular viability of EALs changed significantly after in-vitro culture, suggesting that significant proliferation or death of EALs did not occur during the culture period. Co-culture of the patient's PBLs with autologous pleural effusion for 96 h did not alter the expression of lymphocyte-related antigens on the PBLs. These results indicate that expression of T cell-related antigens, but not B cell- or NK cell-related antigens, on EALs was blocked temporarily by the malignant pleural effusion. This is the first report concerning the existence of a large quantity of unclassified lymphocytes in which the T cell-related antigens were reversibly masked in the malignant pleural effusion.

Antigens, CD19↗

PubMed2002

Tumor suppression through angiogenesis inhibition by SUIT-2 pancreatic cancer cells genetically engineered to secrete NK4.

NK4, composed of the N-terminal hairpin and subsequent four-kringle domains of hepatocyte growth factor (HGF), acts not only as a competitive antagonist of HGF but also as an inhibitor of angiogenesis. By studying the antitumor effect of NK4, we evaluated the potential of gene therapy with NK4 as a treatment for pancreatic cancer. Expression vector pcDNA3-NK4 containing NK4 cDNA was used to transfect human pancreatic cancer cell line SUIT-2. Although the established NK4 transfectant continuously expressed NK4 protein, the expression was shown by migration assay to be insufficient to antagonize HGF in vitro. Proliferation of the NK4 transfectant did not differ significantly from that of a mock transfectant. In vivo, we used models of orthotopic implantation and liver metastasis to transplant NK4-transfected clone or mock-transfected clone into nude mice. Cell proliferation in vivo, evaluated by immunohistochemical staining of proliferating cell nuclear antigen, did not differ between NK4 and mock transfectants, and this was also the finding in the in vitro assay. However, the NK4-transfected clone showed significant inhibition of tumor progression in both the orthotopic implantation and liver metastasis models. The number of vessels within tumors was significantly decreased, and the apoptotic tumor cells were increased in number. The results of these experiments show that genetic modification of tumor cells with NK4 cDNA yields a significant antitumor effect and that this effect is mainly obtained by NK4's function as an angiogenesis inhibitor rather than as an HGF antagonist. We conclude that the potent angiogenesis inhibitor NK4 may be a promising molecule for gene therapy of pancreatic cancer.

Animals↗

PubMedDate not supplied

Candidate host marker for peritoneal dissemination.

BACKGROUND: Mesothelial cell injury is common in peritoneal dissemination (PD) of cancer cells. The plasminogen activator system, including urokinase-type plasminogen activator (uPA) and type-1 plasminogen activator inhibitor (PAI-1), plays an important role in repair of the peritoneum damaged by several types of peritonitis. We investigated and compared the expression of uPA and PAI-1 in the peritoneum of cancer patients with and without PD. MATERIALS AND METHODS: Cancer cell-positive peritoneum and cancer cell-negative peritoneum specimens were obtained from 11 patients with PD, while peritoneum specimens were also obtained from 24 patients without PD. The presence or absence of cancer cells in the peritoneal tissues was confirmed by both hematoxylin-eosin staining and reverse transcriptase-polymerase chain reaction (RT-PCR) detection of carcinoembryonic antigen (CEA) mRNA. uPA and PAI-1 mRNA expression in these peritoneal tissues was determined by RT-PCR and the proteins were localized immunohistochemically. The results were compared statistically. RESULTS: uPA mRNA was expressed in the cancer cell-positive peritoneum from 9 of the 11 (81.8%) patients with PD; PAI-1 mRNA was expressed in the peritoneal tissue from 10 of (91.9%) these patients. Either uPA or PAI-1 mRNA was expressed in the cancer cell-negative peritoneum from 8 (72.7%) of the 11 patients with PD, whereas uPA mRNA was expressed in none of the peritoneal tissues from the 24 patients without PD and PAI-1 mRNA was expressed in specimens from 4 (16.7%) of these patients. Immunohistochemical analysis revealed uPA and/or PAI-1 in the mesothelial cells and submesothelial fibroblasts in cancer cell-negative peritoneum from the patients with PD but not in peritoneum from the patients without PD. CONCLUSION: uPA transcription in the peritoneum may be a host marker indicating the existence of PD.

Adult↗

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

Increased nuclear factor-kB activation in human colorectal carcinoma and its correlation with tumor progression.

OBJECTIVES: Nuclear factor-kB (NF-kB) is a transcription factor that participates in the induction of several genes for cytokines and enzymes that play important functional roles in various cell types. The aim of this study was to determine NF-kB activation status in human colorectal carcinoma and its correlation to the clinicopathological characteristics of patients. MATERIALS AND METHODS: We examined the activation status of NF-kB in 28 resected colorectal carcinomas and in colonic mucosa from uninvolved portions of these specimens by electrophoretic mobility shift assay (EMSA) and immunohistochemical staining for the p65 subunit of NF-kB. RESULTS: EMSA showed much greater activation in the tumors than in normal mucosa, as did epithelial p65 immunostaining. NF-kB activation significantly increased in the more progressed cases (T3 + T4 cases or Stage II< cases). In vitro studies using lipopolysaccharide (LPS)-responsive colon carcinoma cells suggested a correlation between NF-kB activation and cell proliferation. CONCLUSION: Our findings indicated that NF-kB is constitutively activated in human colorectal carcinoma tissue and correlates with tumor progression. The regulation of this transcription factor might be therapeutically useful against these tumors.

Adenocarcinoma↗

PubMedDate not supplied

Evaluation of a dysfunctional and short-lived subset of monocyte-derived dendritic cells from cancer patients.

Monocyte-derived dendritic cells (Mo-DCs) were generated from peripheral blood monocytes of 12 healthy volunteers (hMo-DCs) and 11 patients (pMo-DCs) with malignancies by culture for 7 days with granulocyte-macrophage colony-stimulating factor and interleukin-4. In this study, we focused on the cytogram pattern by FACS analysis. A gate (R1) was set up by which more than 95% of hMo-DCs were contained. Mo-DCs having lower side scatter than the R1 (R2) comprised 4.5% of hMo-DCs and 24.2% of pMo-DCs. Expressions of antigen presentation-related molecules and phagocytic ability in the R2 of pMo-DCs were lower than those in the R1 population. The R2, but not R1, in pMo-DCs decreased in number between days 7 and 14, and expression levels of antigen presentation-related molecules in the living pMo-DCs on day 14 increased. The 11 patients received dendritic cell vaccine therapy with autologous, tumor-pulsed mature Mo-DCs (day 7). The low R2 group (R2 < or = 10%, 3 patients) had a significantly higher positive delayed-type hypersensitivity reaction against autologous tumor-pulsed Mo-DCs than that of the high R2 group (R2 > 10%, 8 patients) (p<0.001). These results indicate that the R2 of pMo-DCs may be a dysfunctional and short-lived subset.

Adult↗

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↗