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H Hamada

Publications and source records attributed to H Hamada.

At least 235 records · Page 13Linked to original sources
PubMed1998

Transcriptional regulatory region of Brn-2 required for its expression in developing olfactory epithelial cells.

Brain-2 is a class III POU transcription factor expressed in developing nervous system. In this study, we have examined the transcriptional regulatory region of Brn-2. Expression of Brn-2 is activated when P19 embryonal carcinoma cells are induced to differentiate into neural cells with retinoic acid (RA). In P19 cells, the 0.5 kb upstream region of Brn-2 was sufficient for the transcriptional activation during RA-induced differentiation. Deletion analysis of the 0.5 kb region located a proximal enhancer (between -422 and -379 with respect to the translational initiation codon), which was essential for the activation. By gel shift assay and methylation interference assay, a specific binding factor was detected that recognized a core sequence GAGCCAAT found within the proximal enhancer. To examine whether the 0.5 kb upstream region can function in embryos, transgenic mice were generated that contained LacZ gene driven by the 0.5 kb upstream region. In these transgenic mice, LacZ was expressed in developing olfactory epithelial cells between embryonic day 12.5 and 14.5. Immunostaining with an anti-Brain-2 antibody demonstrated the expression of Brain-2 in the olfactory epithelium (most likely olfactory receptor neurons) at similar developmental stages. These results suggest that the 0.5 kb upstream region of Brn-2 is sufficient for the expression in the developing olfactory cells and that the DNA binding factor recognizing the proximal enhancer may be involved in the olfactory cell specific expression.

Animals↗
PubMed1998

Adenovirus-mediated transduction of Escherichia coli uracil phosphoribosyltransferase gene sensitizes cancer cells to low concentrations of 5-fluorouracil.

5-fluorouracil (5-FU), although a widely used chemotherapeutic agent, has a limited effect in the treatment of human solid tumors due to their resistance to the cytotoxic effects of 5-FU. Escherichia coli uracil phosphoribosyltransferase (UPRT) is a pyrimidine salvage enzyme that catalyzes the synthesis of UMP from uracil and 5-phosphoribosyl-alpha-1-diphosphate. The present study demonstrates that adenovirus-mediated transduction of E. coli UPRT gene results in marked sensitization of colon, gastric, liver, and pancreas cancer cell lines to low concentration of 5-FU in vitro. The in vitro bystander effect was observed when only 10% of the hepatoma Hep3B cells were infected with UPRT-expressing adenovirus. In addition, 5-FU treatment of human hepatoma or gastric cancer xenografts in nude mice transduced with UPRT was demonstrated to result in significant in vivo antitumor effects. The adenovirus vector transduction of the UPRT gene followed by 5-FU administration is representative of a new chemosensitization strategy for cancer gene therapy.

Adenoviridae↗
PubMed1998

Functional analysis of CD82 in the early phase of T cell activation: roles in cell adhesion and signal transduction.

To define T cell co-stimulatory molecules that work in the early phase of T cell activation, we established monoclonal antibodies (mAb) that inhibit or enhance T cell activation by the histiocytic leukemia cell line U937. One of the mAb, 53H5, which recognized both T cells and U937, was identified to bind to CD82 by expression cloning. Functional analyses of CD82 revealed that 1) CD82 needs to exist on both T cells and U937 for the full activation of T cells; 2) CD82 expression is up-regulated on both T cells and U937 by stimulation such as CD3 ligation or treatment with phorbol 12-myristate 13-acetate; 3) overexpression of CD82 enhances both homotypic and heterotypic cell adhesion between T cells and U937; 4) CD82 signal co-stimulates T cells and the signal works synergistically with the CD28-mediated T cell co-stimulation signal; 5) in mixed leukocyte reactions using U937 as stimulator cells, CD82 overexpression on U937 correlates with the higher allogeneicity of U937 cells. These results indicate that CD82 co-stimulates T cells not only by sending intra-T cell signals that work synergistically with CD28 signals but also by inducing enhanced T cell-antigen-presenting cell interaction.

Antigens, CD↗
PubMed1998

Gene therapy for hepatic micrometastasis of murine colon carcinoma.

BACKGROUNDS/AIMS: Pit cells are located in the hepatic sinusoids and are organ-associated natural killer cells that contribute to immune surveillance in the liver. In the present study, the interleukin-2 gene was introduced into hepatocytes using an adenovirus vector to induce interleukin-2 production in an attempt to enhance the natural killer activity of pit cells, leading to inhibition of metastasis of colon carcinoma. METHODS: The recombinant adenovirus vector "Adex1CAmIL2" was constructed by inserting an expression unit which was composed of the CAG promotor (cytomegalovirus enhancer plus chicken beta-actin promotor), murine interleukin-2 cDNA, and a rabbit beta-globin polyadenylation signal. After administration of Adex1CAmIL2 to mice (4x10(7) pfu per animal), the expression of murine interleukin-2 in hepatocytes was examined by immunostaining and in situ hybridization, and the natural killer activity of hepatic mononuclear cells was measured. Inhibition of hepatic metastasis of colon carcinoma was examined after infusion of colon 38 tumor cells into the superior mesenteric vein. RESULTS: After administration of Adex1CAmIL2, interleukin-2 mRNA expression was demonstrated in hepatocytes until day 7, and the serum interleukin-2 level was increased. The natural killer activity of hepatic mononuclear cells was markedly enhanced for 7-10 days. Hepatic metastasis was inhibited by administration of Adex1CAmIL2 until day 7 after tumor cell inoculation. CONCLUSION: These results suggest that gene therapy using Adex1CAmIL2 could be potentially useful for inhibiting hepatic micrometastasis by enhancing the natural killer activity of pit cells.

Actins↗
PubMed1998

Morphological, biochemical and molecular biological characteristics of a granulocyte colony-stimulating factor-producing human eccrine carcinoma cell line.

We describe here a newly established cell line from an eccrine carcinoma which produced an abundant amount of granulocyte colony-stimulating factor (G-CSF). An eccrine carcinoma of the scalp of a 69 year-old-Japanese female had metastasized to the pleura. Clinically, she had marked neutrophilia (up to 60,000/mm3), and a high level of G-CSF (38.7 x 10(3) pg/ml) was detected in the pleural effusion, as determined by enzyme-linked immunosorbent assay (ELISA). We established a cell line in vitro and maintained the cells in culture for 30 months in 90 subcultures. We investigated whether these tumor cells were able to produce G-CSF in culture and found that they were. We also found that the amount of G-CSF produced paralleled the rise in cell number (26.5 x 10(3) pg/ml at confluency). When culture media were administered to rabbits (25 ml/rabbit), the amount of circulating neutrophils increased until the number was equal to or greater than that resulting from injection of recombinant human G-CSF (rhG-CSF)(75 micrograms). This effect persisted for 7 days. When tumors were induced in SCID and nude mice by injecting cultured cells (1 x 10(7) cells/mouse), the number of circulating neutrophils also correlated well with tumor size in these mice (200,000/mm3, 3 cm tumor). After tumor removal, the neutrophil number returned to normal within 30 days. G-CSFmRNA in cultured, cells was detected by RT-PCR. Based on these results, it was confirmed that the marked neutrophilia observed in the patient was caused by the tumor-generated G-CSF. This is the first G-CSF-producing cell line developed from a cancer of the skin.

Adenocarcinoma↗
PubMed1998

Glucose intolerance and adenomas of the sigmoid colon in Japanese men (Japan).

OBJECTIVES: The purpose was to investigate the relation between glucose tolerance and risk of sigmoid colon adenomas, a well-established precancerous lesion, in Japanese men. METHODS: In the consecutive series of 7,637 men aged 48 to 59 years who received a preretirement health examination at four hospitals of the Self Defense Forces (SDF) in Japan from 1986 to 1994, we identified 821 cases of sigmoid colon adenomas and 4,372 controls with normal sigmoidoscopy or colonoscopy at 60 cm or more from the anus. Glucose tolerance status was classified as normal, impaired glucose tolerance (IGT), newly diagnosed non-insulin dependent diabetes mellitus (NIDDM), or diabetes mellitus under treatment, based on a 75g oral glucose tolerance test and medical history. Statistical adjustment was made for body mass index (wt/ht2), cigarette smoking, alcohol use, rank of the SDF, and hospital. RESULTS: Modest increases in adenoma risk were observed for newly diagnosed NIDDM and diabetes mellitus under treatment while there was no association between IGT and adenoma risk. When small (< 5 mm in diameter) and large (5+ mm) adenomas were analyzed separately, increased risk associated with newly diagnosed NIDDM was more pronounced for small adenomas, and diabetes mellitus under treatment showed a slightly stronger association with large adenomas. CONCLUSIONS: The findings suggest that NIDDM is associated with modestly increased risk of sigmoid colon adenomas, and add to evidence that hyperinsulinemia increases colon cancer risk.

Adenoma↗
PubMed1998

Vaccine effect of granulocyte-macrophage colony-stimulating factor or CD80 gene-transduced murine hematopoietic tumor cells and their cooperative enhancement of antitumor immunity.

To develop immunogene therapy targeting minimal residual hematopoietic tumor cells in patients, we transduced murine GM-CSF or CD80 gene into murine WEHI 3B myelomonocytic leukemia and EL-4 thymic lymphoma cells using retroviral vectors and evaluated their effects on inducing antitumor responses in syngeneic host mice. Subcutaneously injected GM-CSF- and CD80 gene-transduced WEHI 3B (GMCSF/WEHI/3.2 or CD80/WEHI/1.8, respectively) cells lost their original tumorigenicity in immunocompetent syngeneic mice. Results from tumor inoculation experiments using athymic nude mice suggested that the rejection of GMCSF/WEHI/3.2 in immunocompetent mice depended fully on T cells and that of CD80/WEHI 1.8 depended partly on T cells and partly on NK cells. In both WEHI 3B and EL-4 models, irradiated GM-CSF gene-transduced cells provided strong immuno-protection against wild-type cells, but irradiated CD80 gene-transduced cells did not. A remarkably high cooperative effect was obtained when irradiated GMCSF/EL-4 and CD80/EL-4 were inoculated together. These results suggested that the tumor vaccine effect is efficiently enhanced by GM-CSF gene transduction and CD80 gene transduction induces some protective antitumor immunity in co-operation with GM-CSF gene transduction.

Animals↗
PubMed1998

Adenovirus-mediated GM-CSF gene and cytosine deaminase gene transfer followed by 5-fluorocytosine administration elicit more potent antitumor response in tumor-bearing mice.

Antitumor effects of combined transfer of suicide and cytokine genes were investigated in this study. Adenovirus harboring E. coli cytosine deaminase gene (AdCD) and adenovirus harboring murine granulocyte-macrophage colony-stimulating factor gene (AdGMCSF) were used simultaneously for in vivo gene transfer in melanoma-bearing mice. Growth inhibition of established tumors and prolongation of survival period were observed more significantly in tumor-bearing mice after transfection with AdGMCSF and AdCD followed by continuous injection of prodrug 5-fluorocytosine (5FC) when compared with mice treated with control adenovirus AdlacZ/5FC, AdCD/5FC or AdGMCSF alone (P < 0.01). After combined therapy the expression of MHC-I (H-2Db) and B7-1 molecules on freshly isolated tumor cells increased greatly and more dendritic cells and CD8+ T cells infiltrated into the tumor mass. The activity of specific cytotoxic T lymphocytes was also found to be induced more significantly after the combined therapy. Further experiments showed that apoptosis of tumor cells and induction of antitumor immune response might be involved in the mechanisms of the tumor cell killing by the combined therapy. Our results demonstrated that combined transfer of the GM-CSF and CD suicide genes, being able to inhibit the growth of melanoma synergistically and induce specific antitumor immune response efficiently, thus addressing the drawbacks of suicide gene therapy or cytokine gene therapy which were proved to be not satisfactory when used alone, might be of therapeutic potential for gene therapy of cancer.

Adenoviridae↗
PubMed1998

Epigenetic reprogramming of the human H19 gene in mouse embryonic cells does not erase the primary parental imprint.

BACKGROUND: Genomic imprinting in mammals is thought to result from epigenetic modifications to chromosomes during gametogenesis, which leads to differential allelic expression during development. There is a requirement for an appropriate experimental system to enable the analysis of the mechanisms of genomic imprinting during embryogenesis. RESULTS: To develop a novel in vitro system for studying the molecular basis of genomic imprinting, we constructed mouse cell lines containing either a paternal or maternal human chromosome 11, by microcell-mediated chromosome transfer. Allele-specific expression and DNA methylation studies revealed that the imprinting status of the human H19 gene was maintained in mouse A9 mono-chromosomal hybrids. Each parental human chromosome was introduced independently into mouse near-diploid immortal fibroblasts (m5S) and two embryonal carcinoma (EC) cell lines (OTF9-63 and P19). The paternal allele of human H19 remained in a repressed state in m5S cells, but was de-repressed in both EC cells. The paternal H19 allele was demethylated extensively in OTF9-63 cells, whereas the only alteration in P19 hybrids was de novo methylation on both alleles in the 3' region. Following in vitro differentiation, the expressed paternal H19 allele was selectively repressed in differentiated derivatives of EC hybrids. CONCLUSION: These results indicated that human imprint marks could function effectively in mouse cells, and that the imprinting process was epigenetically reprogrammed in embryonal carcinoma cells, without erasure of the primary imprint that marked the parental origin. Therefore, these mono-chromosomal hybrids could provide a valuable in vitro system to study the mechanisms involved in the regulation of imprinted gene expression.

Animals↗
PubMed1998

In vivo adenovirus-mediated prodrug gene therapy for carcinoembryonic antigen-producing pancreatic cancer.

In gene therapy for malignancy, the herpes simplex virus thymidine kinase (HSVtk)-ganciclovir (GCV) system has been widely used. For pancreatic cancer targeting, we estimated the therapeutic efficacy of gene transduction by an adenovirus-carrying HSVtk gene under the control of a carcinoembryonic antigen (CEA) promoter (AdCEAtk) followed by systemic administration of GCV. Four cell lines, CEA-producing Su.86.86. BxPC-3 (pancreatic cancer cells), MKN45 (gastric cancer cells) and CEA-nonproducing HeLa, were used for analysis of GCV sensitivity induced by adenoviral gene transduction. To evaluate the therapeutic efficacy of AdCEAtk and GCV administration in human CEA-positive pancreatic cancer in vivo, a subcutaneously implanted tumor-bearing nude mouse model was used. When the HSVtk gene was transduced with a ubiquitous promoter into these cells, increase of the GCV sensitivity was independent of CEA-production. In contrast, when the cells were transduced with a CEA promoter, the cell-killing effect of GCV was increased in only CEA-producing cells. For in vivo analysis, AdCEAtk was delivered into subcutaneously established tumors of Su.86.86 cells. Immunohistochemical staining of the tumor showed that HSVtk protein was expressed only in tumor cells, and tumor growth was markedly suppressed by administration of GCV. These results suggest that the adenovirus-mediated transfer of HSVtk gene with CEA promoter specifically increases the GCV sensitivity of CEA-producing pancreatic cancer cells in vitro and in vivo. This strategy may provide a useful tool for treating pancreatic cancer, especially CEA-producing tumor cells.

Adenoviridae↗
PubMed1998

Circulating KL-6 predicts the outcome of rapidly progressive idiopathic pulmonary fibrosis.

Searching for early predictive markers of the therapeutic effects of high-dose corticosteroids ("pulse therapy") on patients with rapidly progressing idiopathic pulmonary fibrosis (IPF), we evaluated 14 such patients, who had received weekly pulse therapy for at least 3 wk. Eight patients responded to the treatment and survived. However, six patients failed to respond, and all of them died within 3 mo after treatment. Serum levels of KL-6 (MUC1 mucin), neutrophil elastase (NE), and lactate dehydrogenase (LDH) were measured before, and at 1 wk and 3 wk after treatment. Levels of KL-6 decreased significantly in patients who lived, whereas KL-6 levels tended to increase in patients who died. The values of NE did not change significantly. LDH levels decreased significantly at 1 wk, and tended to decrease at 3 wk in patients who lived. However, in patients who died, they did not significantly change. At the first cycle of treatment when clinical effects may not be evident, the decrease in KL-6 but not LDH levels was significantly related to a favorable outcome, whereas their increase was related to a poor outcome. Results suggest that monitoring with KL-6 may contribute to early clinical decisions for alternative therapy in the management of rapidly progressing IPF.

Aged↗
PubMed1998

Health policy in transition: terminal care and site of death in Japan.

OBJECTIVES: In Japan, hospitals have replaced homes as the predominant site of death, especially for the elderly. Site of death is a reliable indicator of where older people receive care before they die. We conducted a population-based study to identify the factors that determine site of death in a typical rural area in Japan. METHODS: Study subjects were residents of Kawakami town, aged 70 years or older, who died during 1981 and 1990. Death certificates provided information on age, gender, cause of death, duration of illness before death, family members, family occupation, and site of death. RESULTS: Among 455 subjects, 52.7% died at home, while 47.3% died in hospital. Multiple logistic regression analyses indicated that subjects with cancer were 6.1 times more likely to die in hospitals than those with other diseases. Subjects who died in their seventies were 2.3 times more likely to die in hospital than older subjects. Members of non-farming families were 1.7 times more likely to die in hospital than members of farming families. Gender, duration of illness, and the presence of spouse or children in the household were not significantly related to site of death according to multivariate analyses, although trends did exist. CONCLUSION: This case study illustrates the importance of developing geriatric care systems in Japan, utilizing alternatives to hospitals, such as nursing homes and formal home care. This is particularly true for patients with cancer. As the older population rapidly increases in Japan, the need for alternatives in geriatric care grows more critical.

Aged↗
PubMed1998

KL-6 as a serologic indicator of Pneumocystis carinii pneumonia in immunocompromised hosts.

KL-6, a serum marker for interstitial pneumonitis, was evaluated in patients with Pneumocystis carinii pneumonia (PCP). Patient 1 was a 56-year-old woman with rheumatoid arthritis treated with immunosuppressive drugs and corticosteroids. Patient 2 was a 59-year-old man with a glioblastoma who received anti-cancer drugs and corticosteroids. In both patients, serum KL-6 showed an abnormally high level due to the complication of PCP, and it decreased following successful treatment. These results indicate that PCP is one of the diseases in which serum KL-6 increases.

Antigens↗
PubMed1998

Pseudo-cerebrospinal fluid rhinorrhea after skull base surgery.

A 41-year-old female underwent complete resection of a left petroclival meningioma via an anterior transpetrosal approach, during which the greater superficial petrosal nerve was divided. On the 14th day after the operation, she first noticed leakage of clear fluid from her right nostril whenever the ambient room temperature rose. This pseudo-cerebrospinal fluid rhinorrhea may have developed because of parasympathetic hypersensitivity due to division of the greater superficial petrosal nerve.

Adult↗