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Shumpei Ohnami

Publications and source records attributed to Shumpei Ohnami.

9 recordsLinked to original sources
PubMed2005

Intraperitoneal injection of adenovirus expressing antisense K-ras RNA suppresses peritoneal dissemination of hamster syngeneic pancreatic cancer without systemic toxicity.

We examined the antitumor effect and safety of the adenovirus-mediated expression of antisense K-ras RNA in two peritoneal dissemination models of pancreatic cancer. First, we found that the infection of an adenovirus vector expressing antisense human K-ras RNA (AxCA-AS) induced significant apoptosis in vitro in human pancreatic cancer cells with K-ras mutation. Second, the intraperitoneal (ip) injection of AxCA-AS effectively suppressed the growth of human pancreatic cancer cells in the peritoneal cavity of nude mice. Third, in the hamster syngeneic peritoneal dissemination model, the ip injection of an adenovirus expressing antisense hamster K-ras RNA significantly suppressed the peritoneal growth of hamster pancreatic cancer cells, and no significant systemic toxicity was observed in the treated hamsters. This study suggests a feasibility of the development of a therapeutic strategy against pancreatic cancer based on the adenovirus-mediated transduction of an antisense K-ras construct.

Adenoviridae↗
PubMed2005

Association of habitual smoking and drinking with single nucleotide polymorphism (SNP) in 40 candidate genes: data from random population-based Japanese samples.

Basic information on the association between lifestyle factors and candidate genes is valuable for genetic-environmental study. We screened the association of habitual smoking or drinking with polymorphism in 40 candidate genes for a total of 153 single nucleotide polymorphisms (SNPs) using a sample of 339 middle-aged, randomly selected Japanese men. Smoking and drinking statuses were elicited during questionnaire-based interviews. Genes were selected based on their possible involvement in genetic-environmental, life-style interactions and constitute the genes expressing xenobiotic metabolism enzymes, DNA repair enzymes, and other stress-related proteins. The P values of odds ratios to habitual smoking for CYP17A1, ESR1, EPHX1, GSTT2, ALDH2, NOS2A, OGG1, and SLC6A4 and those of odds ratios to habitual drinking for CYP1B1, ESR1, HSD17B3, GSTM3, COMT, ADH1C, ALDH2, NOS3, and NUDT1 were under 0.05. These variables were included in a stepwise logistic analysis in order to develop a predictive model for smoking or drinking behavior. In the final model, the only significant variables selected for smoking were OGG1, SLC6A4, EPHX1, ESR1, and CYP17A1, and for drinking, ALDH2 and NUDT1. The findings of the present study suggest that polymorphism in associated candidate genes plays a role in the habitual use of tobacco and alcohol among Japanese men.

Adult↗
PubMed2004

Interferon-alpha and antisense K-ras RNA combination gene therapy against pancreatic cancer.

Interferon alpha (IFN-alpha) is used worldwide for the treatment of a variety of cancers. For pancreatic cancer, recent clinical trials using IFN-alpha in combination with standard chemotherapeutic drugs showed some antitumor activity of the cytokine, but the effect was not significant enough to enlist pancreatic cancer as a clinically effective target of IFN-alpha. In general, an improved therapeutic effect and safety are expected for cytokine therapy when given in a gene therapy context, because the technology would allow increased local concentrations of this cytokine in the target sites. In this study, we first examined the antiproliferative effect of IFN-alpha gene transduction into pancreatic cancer cells. The expression of IFN-alpha effectively induced growth suppression and cell death in pancreatic cancer cells, an effect which appeared to be more prominent when compared with other types of cancers and normal cells. Another strategy we have been developing for pancreatic cancer targets its characteristic genetic aberration, K-ras point mutation, and we reported that the expression of antisense K-ras RNA significantly suppressed the growth of pancreatic cancer cells. When these two gene therapy strategies are combined, the expression of antisense K-ras RNA significantly enhanced IFN-alpha-induced cell death (1.3- to 3.5-fold), and suppressed subcutaneous growth of pancreatic cancer cells in mice. Because the 2',5'-oligoadenylate synthetase/RNase L pathway, which is regulated by IFN and induces apoptosis of cells, is activated by double-strand RNA, it is plausible that the double-strand RNA formed by antisense and endogenous K-ras RNA enhanced the antitumor activity of IFN-alpha. This study suggested that the combination of IFN-alpha and antisense K-ras RNA is a promising gene therapy strategy against pancreatic cancer.

Adenoviridae↗
PubMed2004

Development of gene therapy to target pancreatic cancer.

Pancreatic cancer remains one of the most difficult cancers to treat. Its high propensity to infiltrate and metastasize early from a small primary focus necessitates development of a new therapy which can track down the disseminated cancer cells in vivo. Gene therapy may offer new opportunities for a variety of targeting strategies, and we review here some of our work related to the development of targeted gene therapy: 1) Targeting by specific molecular abnormality: Many pancreatic cancer cells show "addiction" to K-ras mutation, while normal cells appear resistant to suppression of K-ras-mediated signaling by antisense K-ras RNA expression adenoviral vector. 2) Targeting by in vivo tumor characteristics: In a peritoneal dissemination model, intraperitoneal lipofection/polyfection can deliver and express transgenes highly preferentially in tumor nodules. 3) Targeting by vector: An efficient protocol for construction of an adenovirus expression vector library has been developed, which will enable a direct functional selection of fiber knob-modified targeting vector species for given cells. 4) Targeting by tumor immunity: Several cytokines not only induce direct cytotoxicity, but are also expected to activate specific immunity to achieve targeted suppression of cancer cells in vivo. Unlike parenteral administration of short-lived recombinant interferon protein, local interferon gene transfer can provide a target tissue-restricted distribution and sustained expression, which may improve the efficacy/safety balance of cytokine therapy. Cancer gene therapy development is, in general, at the stage of proof of principles and safety. However, it is an art of integrated science. The recent rapid progress of related sciences and technologies will expand the potential and consolidate the clinical reality of gene therapy.

Adenocarcinoma↗
PubMed2003

Allele frequencies of single nucleotide polymorphisms (SNPs) in 40 candidate genes for gene-environment studies on cancer: data from population-based Japanese random samples.

Knowledge of genetic polymorphisms in gene-environment studies may contribute to more accurate identification of avoidable risks and to developing tailor-made preventative measures. The aim of this study was to describe the allele frequencies of single nucleotide polymorphisms (SNPs) of select genes, which may be included in future gene-environment studies on cancer in Japan. SNP typing was performed on middle-aged Japanese men randomly selected from the general population in five areas of Japan. We genotyped and calculated allele frequencies of 153 SNPs located on 40 genes: CYP1A1, CYP1B1, CYP2C9, CYP2C19, CYP2E1, CYP17A1, CYP19A1, AHR, ESR1, ESR2, ERRRG, PGR, EPHX1, EPHX2, HSD17B2, HSD17B3, GSTM2, GSTM3, GSTT2, GSTP1, NAT1, NAT2, COMT, ADH1A, ADH1B, ADH1C, ALDH2, NOS2A, NOS3, IL1A, IL1B, OGG1, NUDT1 [MTH1], DRD2, DRD3, DRD4, SLC6A4, NR3C1 [GCCR], MTHFR, and NQO1. In the present study, the Japanese allele frequencies were verified by using nationwide population samples.

Alleles↗
PubMed2003

Expression profiles of pancreatic cancer cell lines infected with antisense K-ras-expressing adenoviral vector.

The point mutations of the K-ras gene occur in as high as 70-90% of the cases with adenocarcinoma of the pancreas and apparently represent one of the key and early events in the carcinogenesis. However, the specific influence of the K-ras activation on global gene expression profiles in pancreatic cancer cells has not been elucidated. In this study, to promote elucidation of the K-ras-triggered molecular cascade(s) in pancreatic cancer, four pancreatic cancer cell lines with K-ras point mutations were infected with an adenovirus vector expressing an antisense K-ras RNA (AxCA-AS), and the change of gene expression was analyzed by oligonucleotide-based microarrays containing 12,626 genes. Among the genes showing more than 2-fold differences in the expression levels between the control- and antisense-K-ras-transduced cells, 7 genes were commonly up-regulated and 4 genes were commonly down-regulated in three or all of the four pancreatic cancer cell lines transduced with AxCA-AS. The altered gene expression levels observed by microarrays were confirmed by real-time RT-PCR methods. Then, the expression of the 4 down-regulated genes was examined in the untransduced surgical specimens of pancreatic cancer. The G-protein coupled receptor RE2 and phenylethanolamine N-methyltransferase had negligible expression levels in all pancreatic cancers, whereas the syntaxin 1A and p120 catenin isoform were significantly up-regulated in pancreatic cancers containing K-ras mutations compared with a pancreatic cancer with wild type K-ras gene. The transcriptional regulation of those genes may be a part of the molecular cascades triggered by K-ras activation leading to the development and/or progression of pancreatic cancer.

Adenoviridae↗
PubMed2003

Adenovirus-mediated gene transfer of interferon alpha inhibits hepatitis C virus replication in hepatocytes.

Recently we reported that on-site interferon (IFN)-alpha production in the liver using an adenovirus vector can achieve a substantial confinement of IFN-alpha in the target organ and can improve liver fibrosis in a rat liver cirrhosis model. However, the major therapeutic effect of IFN for hepatitis C virus (HCV)-associated liver diseases is its antiviral effect on HCV. As a prelude to the in vivo HCV infection experiment using a primate animal model, here we examined the antiviral effect of IFN-alpha gene transfer into HCV-positive hepatocytes in vitro. The non-neoplastic human hepatocyte cell line PH5CH8 was inoculated with HCV-positive serum. Successful in vitro HCV replication and thus the validity of this model was confirmed by a strong selection for HCV variants determined by sequence analysis of the hypervariable region and an increase of HCV RNA estimated by real time TaqMan RT-PCR. One day after the inoculation of HCV, PH5CH8 cells were infected with adenoviral vectors encoding human IFN-alpha cDNA. HCV completely disappeared 9 days after the adenoviral infection, which is linked to the increase of 2('),5(')-oligoadenylate synthetase activity, suggesting that IFN-alpha produced by gene transfer effectively inhibits HCV replication in hepatocytes. This study supports the development of IFN-alpha gene therapy for HCV-associated liver diseases.

2',5'-Oligoadenylate Synthetase↗
PubMed2003

A simple and efficient method for constructing an adenoviral cDNA expression library.

cDNA expression cloning is a powerful method for the identification of genes that are able to confer a selectable phenotype on specific cell types. An adenovirus vector is characterized by several advantages over plasmid DNA and retroviral vector-mediated gene transfer, such as broad host range and high infectivity. However, an expression cloning protocol using the adenovirus vector has not been reported. We describe here a simple and efficient method for constructing adenovirus cDNA expression libraries based on Cre-lox-mediated in vitro recombination between adenoviral shuttle plasmid cDNA libraries and adenoviral genomic DNA tagged with terminal protein. In a model experiment, EGFP clones present at the frequency of 0.003% in the shuttle plasmid library could be efficiently converted to adenoviral vector in a 6-cm dish under optimized conditions, indicating that high-complexity libraries harboring low-abundance cDNAs can be produced. The efficiency of this system was demonstrated by the isolation of cDNA for CD2 (frequency less than 1 in 0.3 x 10(4) transcripts in T cells) from the human T cells. This effective and versatile method can facilitate the functional identification of genes for a variety of purposes.

Adenoviridae↗