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Biomedical subjects

Masaaki Mizuno

Publications and source records attributed to Masaaki Mizuno.

At least 19 recordsLinked to original sources
PubMed2006

Combination of in vivo angiopoietin-1 gene transfer and autologous bone marrow cell implantation for functional therapeutic angiogenesis.

OBJECTIVE: Autologous bone marrow mononuclear cell (BM-MNC) implantation into ischemic tissues promotes angiogenesis, but a large amount of marrow aspiration is required, which is a major clinical limitation. Angiopoietin-1 (Ang-1) is requisite for vascular maturation during angiogenesis. We examined the impacts of combinatorial Ang-1 gene transfer and low-dose autologous BM-MNC implantation on therapeutic angiogenesis in a rabbit model of hind limb ischemia. METHODS AND RESULTS: Rabbits were divided into 4 groups: phosphate-buffered saline (control), 500 microg Ang-1 plasmid (Ang-1), 1 x 10(6) autologous BM-MNCs (BMC), and Ang-1 plasmid plus BM-MNCs (combination). The Ang-1 group had a greater angiographic score and capillary density compared with the control (P<0.05), but the Ang-1 gene therapy alone did not improve transcutaneous oxygen pressure (TcO2) and skin ulcer score. However, the combination group showed a significant improvement in not only angiographic score and capillary density (P<0.05) but also TcO2 (P<0.05) and skin ulcer score. These efficacies were greater in the combination group compared with the BMC group. CONCLUSIONS: This Ang-1 gene and BM-MNC combination therapy enhances not only quantitative but also qualitative angiogenesis in ischemic tissues. Moreover, the combination therapy will enable a reduction in the amount of BM aspiration required for significant therapeutic angiogenesis.

Angiography↗
PubMed2006

EGFR mutations in patients with brain metastases from lung cancer: association with the efficacy of gefitinib.

Gefitinib--a specific inhibitor of epidermal growth factor receptor (EGFR)-associated tyrosine kinase--has demonstrated efficacy in a subgroup of patients with non-small-cell lung carcinoma (NSCLC) who fail conventional chemotherapy. It is also reported to have an antitumor effect in brain metastases from NSCLC. Additionally, EGFR mutations have shown a strong association with gefitinib sensitivity for NSCLC. Here, we assessed the efficacy of gefitinib in brain metastases from NSCLC and evaluated the association of this efficacy with EGFR mutations. We retrospectively reviewed eight cases in which patients were suffering from brain metastases before the initiation of gefitinib treatment. Brain tumor response could be evaluated by MRI in these patients; EGFR gene analyses were also available. We evaluated whether objective tumor response was observed after gefitinib treatment and assessed the efficacy of gefitinib as effective, noneffective, or not assessable in consideration of the influence of previous radiotherapy. Of the eight patients, the efficacy of gefitinib was assessed as effective in three and as noneffective in three. All three patients demonstrating effective efficacy had EGFR mutations in the tyrosine kinase domain (deletion mutation in two patients and point mutation in one patients), whereas none of the three patients demonstrating noneffective efficacy had EGFR mutations. Gefitinib appears to be effective in treating brain metastases in a subgroup of patients. Our data suggested a possible association between the efficacy of gefitinib in the treatment of brain metastases and EGFR mutations.

Adult↗
PubMed2005

Susceptibility to exogenously added interferon-beta protein depends on intracellular interferon-beta mRNA level in human glioma cells.

Exogenously added human interferon-beta (HuIFN-beta) protein possesses a remarkable antiproliferative activity in human glioma and melanoma. Endogenous HuIFN-beta protein, which is produced by its gene transfer using cationic liposomes, has much more effective antiproliferative activity against these tumors, even in cells resistant to exogenously added HuIFN-beta protein. As the first step to elucidate the possible difference in antiproliferative mechanisms between exogenous and endogenous HuIFN-beta protein, we here investigated the relationship between the intracellular level of its mRNA and susceptibility to exogenously added HuIFN-beta protein. In this study, we used seven human glioma cell lines (SK-MG-1, SK-MG-4, SK-AO2, U87MG, U251SP, U251MG and T98) and one human melanoma cell line (MMAN). At first, we examined the relationship between spontaneous expression of HuIFN-beta mRNA and susceptibility to exogenously added HuIFN-beta protein (50 IU/ml) in human glioma cells and then confirmed a significant correlation between them. Next, we confirmed that administration of 0-100 IU/ml exogenously added HuIFN-beta protein upregulated the HuIFN-beta mRNA in a dose-dependent manner using the RT-PCR technique and that the HuIFN-beta mRNA was suppressed by siRNA for HuIFN-beta in SK-MG-1 and MMAN cells. Furthermore, we confirmed that the siRNA for HuIFN-beta significantly suppressed the antiproliferative effect of SK-MG-1 cells treated with 10-100 IU/ml HuIFN-beta protein and MMAN cells with 25 and 50 IU/ml HuIFN-beta protein. We found this phenomenon in another human glioma cell line, U87MG cells, as well. This finding would suggest that susceptibility to exogenously added HuIFN-beta protein is related to the amount of intracellular HuIFN-beta mRNA in human glioma and melanoma cells.

Cell Line, Tumor↗
PubMed2005

Brain metastases from apocrine carcinoma of the scalp: case report.

Apocrine carcinoma is an extremely rare malignant neoplasm that occurs most frequently in the axilla. Although it usually shows an indolent clinical course, it often metastasizes to regional lymph nodes and sometimes to lungs or bones. However, a literature search did not reveal any report describing the detailed clinical course of brain metastases from apocrine carcinoma. We report a case of a 54-year-old male who suffered from multiple brain metastases from apocrine carcinoma that had originated in the scalp 6 years before. The brain metastases appeared in spite of several regimens of chemotherapy for lung metastases for two years. The tumor in the right frontal lobe was successfully operated. However, the small tumor in the right occipital lobe was not cured by gamma knife surgery, and eventually required second operation. The operation had contributed to his neurologically independent life for about one year until he died for gradual progression of lung metastases. To our knowledge this is the first reported case of metastatic brain tumor from apocrine carcinoma.

Apocrine Glands↗
PubMed2005

IFN-beta down-regulates the expression of DNA repair gene MGMT and sensitizes resistant glioma cells to temozolomide.

Alkylating agents, such as temozolomide, are among the most effective cytotoxic agents used for malignant gliomas, but responses remain very poor. The DNA repair protein O6-methylguanine-DNA methyltransferase (MGMT) plays an important role in cellular resistance to alkylating agents. IFN-beta can act as a drug sensitizer, enhancing toxicity against a variety of neoplasias, and is widely used in combination with other antitumor agents such as nitrosoureas. Here, we show that IFN-beta sensitizes glioma cells that harbor the unmethylated MGMT promoter and are resistant to temozolomide. By means of oligonucleotide microarray and RNA interference, we reveal that the sensitizing effect of IFN-beta was possibly due to attenuation of MGMT expression via induction of the protein p53. Our study suggests that clinical efficacy of temozolomide might be improved by combination with IFN-beta using appropriate doses and schedules of administration.

Antineoplastic Agents, Alkylating↗
PubMed2005

Multicentric atypical teratoid/rhabdoid tumors occurring in the eye and fourth ventricle of an infant: case report.

Atypical teratoid/rhabdoid tumors (AT/RTs) are aggressive malignant tumors found in infants and young children. The tumor is characterized by the presence of a rhabdoid cell component in all cases, but the histological origin is still unclear. Recently, germline mutation of the hSNF5/INI1 gene has been reported in association with AT/RTs. The authors report a rare case of an intraocular AT/RT followed by a fourth ventricular tumor. The results of immunohistochemical studies of the surgical specimens revealed the presence of an AT/RT and from this finding the neural origin was inferred. A novel missense mutation of the hSNF5/INI1 gene was demonstrated by DNA analysis. High-dose chemotherapy with stem cell rescue was effective in treating this patient. The immunohistochemical relationship between rhabdoid cells and the neurogenic zone, which has not been described in AT/RTs, is of great interest in view of the nature of rhabdoid cells.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed2005

Growth inhibition of human pancreatic cancer cells by human interferon-beta gene combined with gemcitabine.

We examined the anti-tumor effect of cationic multilamellar liposome containing human IFN-beta (huIFN-beta) gene against cultured human pancreatic cancer cells. We also evaluated the combined effect of huIFN-beta gene entrapped in liposomes and gemcitabine. Furthermore, we examined the anti-tumor mechanisms of the therapy, with emphasis on the Ras-related signal pathway. Three human pancreatic cancer cell lines (AsPc-1, MIAPaCa-2, and PANC-1) were used in this study. The growth inhibition together with the therapy were evaluated by WST-1 assay; the production of huIFN-beta protein was measured by ELISA; the cell cycle and apoptosis were analyzed using a FACScan flow cytometer; the protein levels of Son of sevenless (SOS-1) and Ras-GAP were measured by Western blotting; and the activation of Ras-GTP was evaluated by the immunoprecipitation method. As a result, we found that huIFN-beta gene entrapped in liposomes demonstrated a strong anti-tumor effect against human pancreatic cancer cells. The treatment that combined huIFN-beta gene entrapped in liposomes and gemcitabine was more effective than each treatment alone. Although gemcitabine remarkably reduced the level of SOS-1, the above combined therapy reduced the level of SOS-1 even more significantly. Both huIFN-beta gene entrapped in liposomes and the com-bination of huIFN-beta gene entrapped in liposomes and gemcitabine increased the level of Ras-GAP, and decreased the activity of Ras-GTP. These results suggest that this combination therapy can induce strong anti-tumor activity against human pancreatic cancer cells through the regulation of the Ras-related signal pathway.

Annexin A5↗
PubMed2005

[Gene therapy for malignant glioma].

Life sciences and computer technologies have begun to create new medical fields such as pharmacogenomics, nutrinogenomics, and genetic medicines (genetic diagnosis and gene therapy). In gene therapies for malignant brain tumors, suicide gene therapies using herpes simplex virus-thymidine kinase gene and ganciclovir, and immuno-gene therapies using cytokine genes have been developed. Recently, we made a gene therapy protocol of our own, which used cationic multilamellar liposomes entrapped with interferon-beta (IFN-beta) gene as a vector and we started clinical trial of IFN-beta gene therapy for patients with malignant glioma in April 2000. Until now, five patients received the treatment and then they are under evaluation on safety and usefulness. Here the authors introduce present and prospect of gene therapy for malignant brain tumors.

Brain Neoplasms↗
PubMed2005

[Gene therapy using cationic multilamellar liposomes containing human interferon-beta gene against renal cell carcinoma].

The anticancer activity of cationic multilamellar liposomes containing human IFN-beta gene (IAB-1) against renal cell carcinoma (RCC) was examined. Concentrations of IFN-beta protein were measured by an enzyme-linked immunosorbent assay. The cytotoxic activity of IAB-1 against RCC cells and normal renal proximal tubule endothelial cells (RPTEC5899) was examined by the microculture tetrazolium dye assay. For the in vivo study, the NC65 RCC cell line was inoculated into severe combined immunodeficiency mouse. The RCC cells treated with IAB-1 secreted significant amounts of IFN-beta protein. Significant in vitro cytotoxic activity of IAB-1 against RCC cells was observed. In contrast, treatment of RCC cells with recombinant IFN-beta protein resulted in less cytotoxicity. No significant cytotoxicity was seen in RPTEC5899 cells. Apoptosis was observed in RCC cells treated with IAB-1. The size of NC65 RCC cancers transfected with IAB-1 in mice was significantly smaller than that receiving injection of empty liposomes or recombinant IFN-beta protein. These findings show that IAB-1 may have significant antitumor activity against RCC, and suggest its potential clinical application for gene therapy against RCC.

Animals↗
PubMed2004

Vaccination with tumor cell lysate-pulsed dendritic cells augments the effect of IFN-beta gene therapy for malignant glioma in an experimental mouse intracranial glioma.

Interferon-beta (IFN-beta) has been used as an antitumor drug against human glioma, melanoma and medulloblastoma since the 1980s. Recently, we developed a new gene therapy using the IFN-beta gene against malignant gliomas and then began clinical trials in 2000. Since stimulation of immune system was one mechanism of antitumor effect induced by IFN-beta gene therapy, we hypothesized that combination of IFN-beta gene therapy with immunotherapy might increase its effectiveness. In the present study, we tested whether combination therapy with IFN-beta gene therapy and immunotherapy using tumor cell lysate-pulsed dendritic cells (DCs) would increase the efficacy of IFN-beta gene therapy. In an experimental mouse intracranial glioma (GL261), which cannot be cured by either IFN-beta gene therapy or DC immunotherapy alone, IFN-beta gene therapy following DC immunotherapy resulted in a significant prolongation in survival of the mice. Moreover, when this combination was performed twice, 50% of treated mice survived longer than 100 days. Considering these results, this combination therapy may be one promising candidate for glioma therapy in the near future.

Animals↗
PubMed2004

Two different mechanisms of apoptosis resistance observed in interferon-beta induced apoptosis of human glioma cells.

Interferon (IFN)-beta is known to exert cytostatic or cytocidal effects in human glioma cells and is widely used in the treatment for gliomas. However, precise mechanisms of cell death induced by IFN-beta are not well understood. In this study, the authors investigated the intracellular signal transduction of IFN-beta in human glioma cells. The cell death process observed in susceptible cells SK-MG-1 was accompanied by characteristic morphological changes of apoptosis, processing of caspases, and DNA fragmentation. Use of caspase inhibitors confirmed the activation of caspases, however activated executioner caspase was caspase-7 rather than caspases-3 or -6. Activation of DNA endonuclease, DNase-gamma was also observed. Observation of other IFN-beta relatively resistant glioma cells (U251SP, T98G, U251MG, U87MG, SK-AO2) revealed two different mechanisms of apoptosis resistance. In contrast to T98G, U87MG, and SK-AO2 which showed no activation of caspases, surprisingly, all the apoptosis process except DNase-gamma activation was observed in U251SP and U251MG cells. Collectively, these findings indicate that IFN-beta induced apoptosis in human glioma cells through activation of caspase-7 and activation of DNase-gamma. The similar activations of caspases were found also in some of the apoptosis resistant cells. These findings may help to improve the IFN-beta therapy in near future.

Antineoplastic Agents↗
PubMed2004

Human gene therapy for malignant gliomas (glioblastoma multiforme and anaplastic astrocytoma) by in vivo transduction with human interferon beta gene using cationic liposomes.

Transfer of interferon beta gene via cationic liposomes has been found to induce regression of experimental glioma. We performed a pilot clinical trial of safety and effectiveness of this interferon beta gene therapy in five patients with malignant glioma (glioblastoma multiforme or anaplastic astrocytoma). Transgene expression and antitumor activity were detected in four patients. Two patients showed a partial response (>50% tumor reduction) and two others had stable disease 10 weeks after beginning therapy. One patient could not be evaluated because of previous treatment with gamma-knife therapy. This study suggests the feasibility and safety of interferon beta gene therapy, which may become an important treatment option for patients with malignant glioma.

Adult↗
PubMed2004

Interferon-beta gene therapy for cancer: basic research to clinical application.

Interferon-beta gene therapy for cancer is the first such protocol developed in Japan. Here we describe the development process of our interferon-beta gene therapy from basic research to clinical application. Interestingly, the biological and biochemical characteristics of interferon-beta gene therapy through transfer of the interferon-beta gene into tumor cells by means of cationic liposomes differed from those of conventional interferon-beta protein therapy. Interferon-beta gene transfer could induce apoptosis in interferon-beta protein-resistant tumor cells, such as glioma, melanoma, and renal cell carcinoma. Induction of apoptosis was related to the level of intracellular mRNA of interferon-beta, prolongation of the phosphorylation time of molecules in the interferon-beta signal transduction pathway, such as JAK1, Trk2, and STAT1, and activation of DNase gamma. In our preclinical study we developed lyophilized cationic liposomes containing interferon-beta gene (gene drug) for clinical use and confirmed their safety. Thereafter, we performed a pilot clinical trial in patients with malignant glioma and confirmed the safety and effectiveness of this interferon-beta gene therapy. In this review we also comment on the status of gene therapy regulation in Japan. Interferon-beta gene therapy is expected to become widely available for clinical use in cancer patients, and this new strategy might be extended to molecular targeting therapy, or used in combination with cell therapy or other therapies.

Apoptosis↗
PubMed2004

Enhancement of C2-ceramide antitumor activity by small interfering RNA on X chromosome-linked inhibitor of apoptosis protein in resistant human glioma cells.

OBJECT: Many human glioma cells are resistant to ceramide. In this study the authors investigated the mechanisms of that resistance and considered ways to overcome it. METHODS: The authors first administered C2-ceramide (N-acetylsphingosine) to human glioma cells from rare cell lines susceptible to C2-ceramide (SKMG1 and U87MG) and other cell lines resistant to it (U251SP, T98G, SKAO2, and U251MG). Following this, the authors analyzed the statuses of transduction signals such as cell viability, morphological changes, caspases, mitochondrial membrane potential, apoptosis-inducing factor, oligonucleosomal DNA fragmentation, and the inhibitor of apoptosis protein (IAP) family. CONCLUSIONS: Ceramide resistance was found to arise from the inhibition of caspase-7 induced by IAPs, especially X chromosome-linked IAP (XIAP). Small interfering RNA (siRNA) on XIAP quenched that resistance in ceramide-resistant human glioma cells (U251SP, T98G, SKAO2, U251MG), indicating that a siRNA for XIAP may be a useful tool for overcoming the resistance to ceramide in human glioma cells.

Antineoplastic Agents↗
PubMed2004

Aurora-B dysfunction of multinucleated giant cells in glioma detected by site-specific phosphorylated antibodies.

OBJECT: The origin of multinucleated giant cells in glioma has not been made clear. In a previous paper the authors studied multinucleated giant tumor cells by using mitosis-specific phosphorylated antibodies to determine the phosphorylation of intermediate filaments and demonstrated that these cells stay in the early mitotic stage, undergoing neither fusion nor degeneration. In the current study the authors investigated the possible genetic causes of multinucleated giant tumor cells. METHODS: Cultured mono- or multinucleated human glioma cells were immunostained with monoclonal antibodies (mAbs) 4A4, YT33, TM71, HTA28, YG72, and alphaAIM-1. The three former antibodies revealed a particular mitotic cell cycle through site-specific phosphorylation of vimentin; that is, the early phase, mid phase, and late phase, respectively. The three later antibodies demonstrated phosphorylation of H3 at Ser28, phosphorylation of vimentin at Ser72, and aurora-B, respectively, making it possible to identify aurora-B distribution and function during mitosis. In addition, paraffin-embedded tissue sections obtained in three patients with giant cell glioblastoma were also examined. Multinucleated giant tumor cells immunoreacted with the mAb 4A4 and alphaAIM-1 but not with YT33, TM71, HTA28, and YG72 in vitro and in vivo. CONCLUSIONS: Findings in this study indicated that multinucleated giant tumor cells remain in the early mitotic phase because of aurora-B dysfunction, effecting aberrations in cytoplasmic cleavage without affecting nuclear division.

Antibodies, Monoclonal↗
PubMed2003

Improvement of transduction efficiency of recombinant adenovirus vector conjugated with cationic liposome for human oral squamous cell carcinoma cell lines.

Adenovirus (Ad) vectors are commonly used in gene therapy trials because of their efficiency in gene transfer. However, their use is limited by immune responses that reduce transgene expression and decrease the efficiency of repeated vector administration. In this study, the efficacy of gene transduction and the tumor-cell killing effect on four human oral (SAS, HSC-2, HSC-3, HSC-4) and one murine squamous cell carcinoma cell (SCC-7, a kind gift of Dr. M. Hiraoka, Kyoto University) lines in vitro with Ad vector conjugated with catioic liposome (Ad/SUV) was evaluated. Ad/SUV resulted in two to five-fold over higher transduction efficiency in four human and one murine cell lines in vitro than Ad vector alone. The optimal Ad-SUV ratio was determined as 10(6) pfu of Ad vector with 1 micromol SUV. Ad/SUV showed more tumor-cell killing effect than Ad vector alone. Furthermore, the shielding effects of Ad vector with Ad/SUV from neutralizing antibody were evaluated. We also found that Ad/SUV is less susceptible to inactivation by neutralizing antibodies in vitro. The efficacy of gene transduction with Ad vector was blocked more than 70% with neutralizing serum, while Ad/SUV retained approximately 50% of the control activity in vitro. On the basis of these results, the anti-tumor effect with suicide gene therapy using Ad/SUV in vivo was evaluated. Three injections of Ad/SUV showed the inhibition of tumor growth compared with control in vivo. Our results suggested that an enhanced anti-tumor effect on human oral squamous cell carcinoma would be obtained with repeated administrations of Ad/SUV.

Adenoviridae↗