Biomedical subjects

O Hino

Publications and source records attributed to O Hino.

At least 37 records · Page 2Linked to original sources

PubMed2000

Mapping and determination of the cDNA sequence of the Erc gene preferentially expressed in renal cell carcinoma in the Tsc2 gene mutant (Eker) rat model.

The Eker rat develops hereditary renal carcinomas (RCs) due to two hit mutations of the tumor suppressor gene, Tsc2. We previously identified using representational difference analysis (RDA), four genes that were expressed more abundantly in an Eker rat RC cell line than in normal kidney tissue. One gene, Erc (expressed in renal carcinoma) showed sequence homology to the mouse and human megakaryocyte potentiating factor (MPF)/mesothelin gene. The present study determines the full sequence of the cDNA and the exon-intron structure of the rat Erc gene and maps its locus in the chromosome by fluorescence in situ hybridization. Rat Erc and its human homologue were localized in chromosomes 10q12-21 and 16p13.3, respectively, both of which coincided with the locus of the Tsc2/TSC gene. We also found that Erc was expressed at higher levels in primary RCs compared with the normal kidney of the Eker rat. Erc may be related to carcinogenesis in the Tsc2 gene mutant (Eker) rat model.

Amino Acid Sequence↗

PubMed2000

Analysis of all exons of TSC1 and TSC2 genes for germline mutations in Japanese patients with tuberous sclerosis: report of 10 mutations.

Twenty-seven Japanese patients with the tuberous sclerosis complex (TSC), consisting of 23 sporadic and 4 familial cases, were tested for mutations in the TSC1 and TSC2 genes, using single-strand conformational polymorphism analysis and direct sequencing. Four possible pathogenic mutations were found in the TSC1 gene, including three frame shifts and a nonsense mutation in a familial case. All mutations were expected to result in a truncated hamartin gene product. The TSC2 gene analysis identified six possible pathogenic mutations only in the sporadic cases, including two frame shifts, one in-frame deletion, and three missense mutations. Two of the TSC2 mutations were expected to result in a truncated tuberin gene product. These results of the Japanese TSC patients were compatible with the reports from Europe and the United States, i.e., (1) TSC1 mutations are rarer in sporadic cases than in familial cases, (2) substantial numbers of sporadic cases arise from mutations in the TSC2 gene, and (3) mutations of the TSC1 gene may cause premature truncation of hamartin.

Adolescent↗

PubMed2000

Distribution of Tsc1 protein detected by immunohistochemistry in various normal rat tissues and the renal carcinomas of Eker rat: detection of limited colocalization with Tsc1 and Tsc2 gene products in vivo.

We and others previously demonstrated that hereditary mutation and a subsequent second hit in the rat homolog of tuberous sclerosis gene (Tsc2) are responsible for Eker renal carcinomas (RC). In humans, alteration in the TSC2 gene is known to cause the tuberous sclerosis complex (TSC) that results in hamartomatous lesions in multiple organs, but the function of TSC2 is not fully understood. In recent years, a second gene (TSC1) responsible for human TSC has been cloned, and binding between TSC1 and TSC2 proteins was reported. In this study, to clarify associations between Tsc proteins in vivo, the expression of Tsc1 protein was detected by immunohistochemistry, and compared with Tsc2 expression. Tsc1 protein was expressed in the nervous system and in many endocrine tissues, including pancreatic islets, the parathyroids, testis, and ovary. Tsc1 was also detected in the many epithelial tissues of organs, such as kidney, uterus, small and large intestine, and liver. Our results indicate overlapping, but not identical, organ distributions of Tsc1 and Tsc2 proteins. At the intracellular distribution, double fluorescent immunolabeling allowed the determination that only a partial portion of Tsc1 signals overlapped with Tsc2 in some organs. These results suggest the existence of co-localizing and independent forms of Tsc proteins in endogenous expressions. Additionally, relatively high expression of Tsc1 protein was detected in RC in the Tsc2 mutant (Eker) rat.

Animals↗

PubMed2000

Hepatitis C virus core protein activates the MAPK/ERK cascade synergistically with tumor promoter TPA, but not with epidermal growth factor or transforming growth factor alpha.

Persistent hepatitis C virus (HCV) infection is associated with the development of human hepatocellular carcinoma (HCC), although the mechanism of HCV-related hepatocarcinogenesis remains unclear. Recently, however, the close relationships between the development of HCC and the mitogen-activated protein kinase (MAPK)/extracellular signal-regulated protein kinase (ERK) cascade have been described. In the present study, we investigated the effects of HCV core protein on this MAPK/ERK cascade. HCV core protein significantly activated the MAPK/ERK cascade, including Elk1. We also examined whether HCV core protein acted synergistically along with hepatocyte mitogen-mediated MAPK/ERK activation. Interestingly, Elk-1 activities were further enhanced by the tumor promoter, 12-O-tetradecanoyl phorbol 13-acetate (TPA), but not by hepatocyte mitogens (epidermal growth factor [EGF] and transforming growth factor alpha [TGF-alpha]) in NIH3T3 cells and HepG2 cells expressing HCV core protein. Moreover, the MAPK/ERK activation by HCV core protein was blocked in the presence of the specific MEK1 inhibitor, PD98059. These results indicate that ERK activation by HCV core protein may be independent of hepatocyte mitogen-mediated signaling but synergistic with TPA, and HCV core protein may function at MEK1 or farther upstream of that component.

3T3 Cells↗

PubMed2000

Novel cerebral lesions in the Eker rat model of tuberous sclerosis: cortical tuber and anaplastic ganglioglioma.

The Eker rat is a model for human tuberous sclerosis (TSC) caused by a mutation in the Tsc2 gene. We describe here histological and immunohistochemical findings of the brain lesions in Eker rats, with emphasis on 2 novel lesions found in this study: a cortical tuber and an anaplastic ganglioglioma. The rat cortical tuber resembled those of humans, and further confirmed the value of this animal model as a tool for investigating the molecular pathology of tuberous sclerosis. On the other hand, the rat anaplastic ganglioglioma had features of a malignant neoplasm that are absent from human subependymal giant cell astrocytomas.

Animals↗

PubMed2000

A novel "Nihon" rat model of a Mendelian dominantly inherited renal cell carcinoma.

A novel rat model of hereditary renal cell carcinoma (RC) was found in a rat colony of the Sprague-Dawley strain in Japan, and named the rising "Nihon" rat. In this strain, RCs develop from early preneoplastic lesions, which begin to appear at 4 weeks of age, forming adenomas by the age of 16 weeks. The RCs are predominantly of clear cell type. Southern blot, northern blot and SSCP analyses revealed no change in the Tsc1, Tsc2, VHL, and c-Met genes. Thus, the Nihon rat should be a valuable experimental model for understanding renal carcinogenesis, especially clear cell type, which is common among human RCs.

Animals↗

PubMed2000

A novel gene "Niban" upregulated in renal carcinogenesis: cloning by the cDNA-amplified fragment length polymorphism approach.

A modified AFLP (amplified fragment length polymorphism) method was employed to isolate genes differentially expressed in renal carcinogenesis of Tsc2 gene mutant (Eker) rats. One gene, selected for further investigation, was named "Niban" "second" in Japanese), because it is the second new gene to be found after Erc (expressed in renal carcinoma) in our laboratory. Importantly, "Niban" is well expressed even in small primary rat Eker renal tumors, more than in progressed cell lines, and is also expressed in human renal carcinoma cells, but not in normal human or rat kidneys. Chromosome assignment was to RNO 13 in the rat, and HSA 1. This "Niban" gene is a candidate as a marker for renal tumor, especially early-stage renal carcinogenesis.

Amino Acid Sequence↗

PubMed2000

Hepatitis C virus core protein interacts with 14-3-3 protein and activates the kinase Raf-1.

Persistent hepatitis C virus (HCV) infection is a major cause of chronic liver dysfunction in humans and is epidemiologically closely associated with the development of human hepatocellular carcinoma. Among HCV components, core protein has been reported to be implicated in cell growth regulation both in vitro and in vivo, although mechanisms explaining those effects are still unclear. In the present study, we identified that members of the 14-3-3 protein family associate with HCV core protein. 14-3-3 protein bound to HCV core protein in a phosphoserine-dependent manner. Introduction of HCV core protein caused a substantial increase in Raf-1 kinase activity in HepG2 cells and in a yeast genetic assay. Furthermore, the HCV core-14-3-3 interaction was essential for Raf-1 kinase activation by HCV core protein. These results suggest that HCV core protein may represent a novel type of Raf-1 kinase-activating protein through its interaction with 14-3-3 protein and may contribute to hepatocyte growth regulation.

14-3-3 Proteins↗

PubMed2000

Expression of cyclooxygenase mRNA in the livers of mice with interferon-gamma chronic hepatitis.

Interferon-gamma (IFN-gamma) transgenic mice expressed the IFN-gamma gene in the liver and developed chronic hepatitis. The expression of cyclooxygenase (Cox)-1 and -2 mRNA were studied in the livers of these mice. A faint band of Cox-1 mRNA was observed in the livers of both normal and transgenic mice. Slight expression of Cox-2 mRNA was observed in the normal mouse liver, and this mRNA expression was induced in the transgenic mouse liver. The present results showed the induction of Cox-2 mRNA expression in the livers of transgenic mice with chronic hepatitis.

Animals↗

PubMed2000

Absence of linkage between radiosensitivity and the predisposing atp7b gene mutation for heritable hepatitis in the LEC rat.

The LEC rat is known to be a mutant strain that spontaneously develops heritable hepatitis due to copper accumulation, caused by mutation of the copper-transporting ATPase gene (Atp7b). Immunodeficiency and radiosensitivity have also been observed. Hayashi et al. extensively examined the radiosensitivity of the LEC rat and concluded that its hypersensitivity is controlled by a single autosomal gene. Furthermore, they suggested the possibility that it correlates to copper accumulation due to the Atp7b gene mutation, because ionizing radiation-induced hydroxyl radicals might act in concert with copper-induced hydroxyl radicals. In the present experiment, we analyzed linkage between radiosensitivity and the mutation responsible for hepatitis in F(1) animals of a cross with the F344 rat. Our results clearly demonstrated an absence of any significant association. In addition, partial dominance for radiosensitivity was observed, and radiosensitive (F(1) x LEC) backcross rats were twice as numerous as their radioresistant counterparts, suggesting the possibility of control by two or more recessive genes.

Adenosine Triphosphatases↗

PubMed2000

Expression of the inducible form of the nitric oxide synthase gene in the livers of mice with chronic hepatitis.

The interferon-gamma (IFN-gamma) transgenic mouse expresses the exogenous IFN-gamma gene in the liver and develops chronic hepatitis. For the present experiment, four IFN-gamma transgene (+) mice of 48 weeks of age and 16 IFN-gamma transgene (+) mice of 8 weeks of age were used. The four IFN-gamma transgene (+) mice of 48 weeks of age showed significantly elevated plasma alanine aminotransferase (ALT) and expressed the inducible form of nitric oxide synthase (iNOS) mRNA in the liver. Of the 16 IFN-gamma transgene (+) mice of 8 weeks of age, iNOS mRNA was expressed in the livers of three. These three mice exhibited higher plasma ALT levels than the other mice of 8 weeks of age. The present results suggest that iNOS mRNA expression in the liver might be correlated with the progression of hepatitis.

Alanine Transaminase↗

PubMed2000

Expression of cyclooxygenase-1 and -2 mRNA in rat tissues: tissue-specific difference in the expression of the basal level of mRNA.

The expression of cyclooxygenase (Cox)-1 and -2 mRNA was studied in tissues of Fisher 344 (F344) (n=3) and Brown Norway (BN) (n=3) strain rats using the reverse transcription polymerase chain reaction. Cox-1 mRNA was expressed in the liver, kidney and lung, but not in the heart. Cox-2 mRNA was expressed in the kidney, heart and lung, but not in the liver. The present results showed the differential expression of basal Cox-1 and Cox-2 mRNA in the rat tissues, suggesting that Cox-1 and Cox-2 may contribute to the regulation of normal pathophysiological conditions in a tissue-specific manner. Thus, it is desirable to perform mapping of the basal expression of Cox-1 and Cox-2 in specific organs in the body in order to anticipate the effects of non-steroidal anti-inflammatory drugs on normal pathophysiological conditions. Finally, no difference was observed between F344 and BN rat tissues in the levels of Cox-1 and Cox-2 mRNA expression.

Animals↗

PubMed2000

Drug development with hints from traditional Indian Ayurveda medicine: hepatitis and rheumatoid as an example.

Although many drugs have been developed by pharmaceutical companies, there are many diseases which can not be cured with these drugs. In order to overcome this problem, the combination of Western and Eastern medicine has been proposed. Ayurveda is traditional Indian medicine established B.C. and is accepted throughout the world today. Due to its effectiveness and fewer side effects, Ayurveda will provide us with many hints for drug development. In the present review, we discuss the possible application of Ayurveda in drug development taking into account the following two points, i) herbs used in Ayurveda contain many unknown active components, and ii) Ayurveda provides new therapeutic approaches. In the case of drugs for the treatment of chronic hepatitis, we get hints from active components in the herbs used in Ayurveda. For rheumatism, we obtain hints for new pharmacological approaches from this medicinal approach.

Chemistry, Pharmaceutical↗

PubMed2000

beta-catenin mutations are absent in hepatocellular carcinomas of SV40 T-antigen transgenic mice.

beta-catenin mutations have been found not only in melanoma and prostatic carcinoma but also in hepatocellular carcinomas in human, c-myc, H-ras genes transgenic mice and chemically-induced models. We investigated beta-catenin mutations in human hepatocellular carcinomas (HCCs), Hep G2 cell line and HCCs in SV40 T-antigen transgenic mice, in order to examine whether beta-catenin mutations are frequently observed in HCC in general. We found a point mutation of beta-catenin in one of nine HCCs in human and a deletion of it in Hep G2 cell line. However, we found no mutation in HCC in SV40 TG mice liver.

Animals↗

PubMed2000

[Cancer genetics of TSC2 gene mutant(Eker) rat model].

Cancer is a heritable disorder of somatic cells. Environment and heredity both operate in the origin of human cancer. Hereditary cancers have been important in the understanding of carcinogenesis, and have pointed to the first tumor suppressor genes. Such a hereditary cancer was described in the rat by Reidar Eker in 1954. The Eker rat model of hereditary renal carcinoma is an example of a Mendelian dominantly inherited predisposition to a specific cancer in an experimental animal. We identified a germline mutation in the rat homologous to the human tuberous sclerosis gene (TSC2) as the predisposing Eker gene. The Eker rat provides a valuable experimental model for understanding the mechanisms of disease, and the development of the therapeutic treatments.

Animals↗

PubMed2000

[Tuberous sclerosis].

Tuberous sclerosis is an autosomal dominant disorder in which patients develop hamartomatous lesions in many different organs, most commonly in the brain, heart, kidney and skin. Two TSC-determining loci have been mapped to chromosomes 9q34 (TSC1) and to 16p13.3 (TSC2). These genes act as tumor suppressor genes, but the mechanism of hamartomatous growth is not completely understood. Recently, the prevalence of TSC is increased by new developments such as the imaging techniques. However, in some cases, physicians were not able to diagnose some TSC individuals because they were asymptomatic or because their symptoms or signs were various. In this review, we present the clinical features and molecular analysis.

Chromosomes, Human, Pair 16↗

PubMed1999

Cloning of differentially expressed genes in highly and low metastatic rat osteosarcomas by a modified cDNA-AFLP method.

To identify differentially expressed genes between highly and low metastatic rat transplantable osteosarcomas, we applied a modified AFLP (amplified fragment length polymorphisms) method for cDNA subtraction. The specific point of our modification is selective amplification using suppression PCR technique after restriction enzyme cutting. Our cDNA-AFLP gave high reproducibility (about 95%) in mRNA patterns and enabled us to clone four dominantly expressed genes in a highly metastatic tumor line. Three showed homology with known genes, encoding Ki-67, a proliferation-associated effective marker of malignancy, type IV collagen alpha-3, a major component of basement membrane, and KIAA77 for which the function is unknown. Although one fragment showed no database homology, we revealed a derivation from the rat homologue of the Drosophila melanogaster diaphanous gene (Dia) by cloning of longer cDNA. Dia genes, known to affect actin filament formation, are downstream effectors of Rho small GTPase. The results suggest that alterations in the expression of cytoskeletal protein, basement membrane elements, and proliferative markers may be important for metastasis of osteosarcomas.

Amino Acid Sequence↗

PubMed1999

Unique features of dendritic cells in IFN-gamma transgenic mice: relevance to cancer development and therapeutic implications.

Although induction of interferon gamma (IFN-gamma) and activation of antigen presenting dendritic cells (DCs) are two vital events during an immune response, the impact of endogenous IFN-gamma on DC function has yet to be clarified. The phenotype and function of DCs isolated from mice with high (IFN-gamma-transgenic mouse [Tg]) and undetectable levels of circulating IFN-gamma (normal mice [NM]) were therefore compared. The capacity to stimulate allogenic (p < 0.05) and antigen-specific T lymphocytes (p < 0.05), as well as the ability to produce IL-12 (p < 0.05) and to process soluble protein antigens (p < 0.05) was found to be significantly higher in DCs from the Tg mice compared to the NM case. The presence of activated DCs in a microenvironment of endogenous IFN-gamma suggests that the IFN-gamma-Tg mouse is a suitable animal model to study cancer immunotherapy in vivo.

Animals↗