Biomedical subjects

Y Ogiso

Publications and source records attributed to Y Ogiso.

At least 37 records · Page 2Linked to original sources

PubMed1997

The significance of Ras guanine nucleotide exchange factor, son of sevenless protein, in renal cell carcinoma cell lines.

PURPOSE: The aim of the present study is to clarify the significance of the Ras guanine-nucleotide exchange reaction in the proliferation of human renal cell carcinoma cell lines. MATERIALS AND METHODS: We examined the expression of human son of sevenless-1 (hSos-1) protein and the epidermal growth factor (EGF) receptor in human renal cell carcinoma cell lines by Western blot analysis. Additionally, a dominant negative H-ras mutant, N116Y, which is known to inhibit the Ras guanine-nucleotide exchange reaction, was transfected into these cell lines by lipofection. RESULTS: Human renal cell carcinoma cell lines expressed much higher amounts of the EGF receptor and hSos-1 protein than normal kidney tissue. Moreover, the N116Y ras mutant could strongly suppress cellular proliferation in these cell lines. CONCLUSIONS: Augmentation of the Ras guanine-nucleotide exchange reaction might be essential to the proliferation of human renal cell carcinoma cells.

Carcinoma, Renal Cell↗

PubMed1997

[Clinical evaluation of RT-PCR method for detection of HCV-RNA--with special reference to Amplicor HCV].

Detection of the viral genome in serum is the most reliable way to analyze HCV viremia. In the present study, we evaluated the availability of a new detection kit for HCV-RNA, Amplicor HCV, which is based on the RT-PCR microplate hybridization protocol. The procedure of Amplicor HCV is simple, unlike the conventional RT-nested-PCR method. Although Amplicor HCV assay exhibited the lower sensitivity than the the conventional RT-nested-PCR method (10 x for HCV type 1a, 1b and 2b; 10(3) x for type 2a), Amplicor HCV assay could detect the HCV-RNA in all HCV-RNA positive cases by conventional RT-nested PCR method, except for one case who contained low concentration of HCV-RNA (10 copies/ml). The coincidence rate was 99.2% in 120 clinical samples between two assays. Amplicor HCV assay, moreover, could efficiently evaluate the viremia regardless of anti-HCV-2 antibody titer. This assay was useful for monitoring the effect of interferon therapy during and after administration. These results suggest that Amplicor HCV has an excellent availability for the clinical laboratories.

Hepacivirus↗

PubMed1996

Hepatocyte growth factor and c-met expression in Long-Evans Cinnamon rats with spontaneous hepatitis and hepatoma.

The Long-Evans Cinnamon (LEC) rat is characterized by the spontaneous onset of acute and chronic hepatitis, followed by occurrence of liver cancer, and is thus able to provide a unique experimental model for human genetical liver disease, Wilson's disease. Hepatocyte growth factor (HGF) is a potent hepatotrophic factor in liver regeneration, and its expression is up-regulated in response to liver injuries. We found that the plasma HGF level in LEC rats rose markedly during the fulminant hepatitis phase, fell during the phase of chronic/cholangiofibrosis, and fluctuated during the hepatoma phase. Immunohistological staining of the liver revealed that the number of HGF-positive cells increased remarkably during the fulminant hepatitis phase, and that many of these cells were localized at the portal triads. Fewer HGF-positive cells were observed during the phase of chronic hepatitis. The surface of the hepatocellular carcinoma (HCC) cells and the cytoplasm of the nonepithelial cells in cancerous liver tissues were HGF-positive. The HGF-messenger RNA (mRNA) level in the liver rose in the fulminant hepatitis phase, fell in the chronic hepatitis phase, and was intermediate or high during the hepatoma phase. The expression of c-met mRNA was strong in the tissues of LEC rats with fulminant hepatitis and, especially, in the cholangiofibrosis tissues. c-met mRNA was also detected in HCCs. These results suggest that the HGF-c-met system may play an important role in the regeneration of hepatocytes as well as in the development of HCC in paracrine or autocrine mechanisms.

Animals↗

PubMed1996

Suppression of pancreatic cancer by the dominant negative ras mutant, N116Y.

N116Y, H-ras mutant, possesses dominant negative activity to Ras function. The aim of this study is to assess whether N116Y can inhibit the proliferation of pancreatic cancer cell lines carrying K-ras mutations and cause reversion of the malignant phenotype. We transfected an expression vector of N116Y, pZIP-N116Y, into eight human pancreatic cancer cell lines with K-ras mutations (PCI 10, 19, 24, 35, 43, 55, 64, and 66) by using a lipofection procedure. The growth inhibition activity of N116Y was evaluated by the colony-forming efficiency in selection medium. In order to examine the effect of N116Y on the neoplastic phenotype, we established N116Y-expressing clones and analyzed their growth ability in soft agar and tumorigenicity in nude mice. The growth of the eight pancreatic cancer cell lines was strongly inhibited by the transfection of pZIP-N116Y. Moreover, the N116Y-expressing clones became less spread and lost their anchorage-independent growth ability. Furthermore, they were nontumorigenic in vivo. N116Y significantly inhibits the growth of pancreatic cancer cell lines and causes reversion of the malignant phenotypes. These results suggest that N116Y may be a candidate gene for use in the gene therapy of pancreatic cancer.

Animals↗

PubMed1996

Dome formation induced by v-H-ras oncogene in a human choriocarcinoma cell line.

To investigate the role of ras genes in trophoblastic cell lineage, we transfected the viral H- or K-ras oncogene into a human choriocarcinoma cell line, CCI, and analysed the biological properties of CCI cells expressing an activated ras oncogene. All v-H-ras-expressing clones distinctively formed the hemispherical domes, which represents an in vitro morphological expression of vectorial transport function and are characteristic of the polarized epithelial cells, but none of v-K-ras-expressing clones and control clones did. Microscopic observation demonstrated that those domes were cavities filled with fluid which accumulated between the cell layer and the surface of culture dish. Scanning electron microscopy revealed that the domes were aggregates of round cells with long numerous microvilli and were morphologically similar to a blastocyst. Furthermore, Na(+)-K(+)-ATPase activity, which is associated with the vectorial fluid transport in transporting epithelial cells, was significantly higher in the v-H-ras-expressing clones than that in the v-K-ras-expressing clones and the parental cells. Those domes flattened within 24 h after treatment with a specific inhibitor of Na(+)-K(+)-ATPase, ouabain, and the number of domes decreased in dose-dependent manner, indicating that Na(+)-K(+)-ATPase activity was required for maintainance of domes. These results suggest that up-regulated activity of H-ras but not of K-ras facilitates the vectorial fluid transport through a chorionic cell layer and leads to the dome formation. The function of II-ras in trophoblasts, may therefore, be essential for embryogenesis, especially for supplying the nutrients.

Biological Transport↗

PubMed1995

Gelsolin: a candidate for suppressor of human bladder cancer.

Human transitional cell carcinomas of the bladder frequently reveal chromosomal abnormalities that span a range between chromosome 9p12 and 9qter, even at early stages of bladder carcinogenesis. Because the gene that encodes an actin-regulatory protein, gelsolin, is localized in chromosome 9q33, we examined the expression of gelsolin in a number of human bladder cancer cell lines and tissues. In all 6 cell lines and in 14 of the 18 tumor tissues (77.8%), gelsolin expression was undetectable or extremely low in comparison with its expression in normal bladder epithelial cells. Furthermore, upon the introduction of the exogenous human or mouse authentic gelsolin cDNA into a human bladder cancer cell line, UMUC-2, gelsolin transfectants of UMUC-2 greatly reduced the colony-forming ability and the tumorigenicity in vivo. These results suggest that gelsolin plays a key role as a tumor suppressor in human urinary bladder carcinogenesis.

Base Sequence↗

PubMed1995

Protective effects of macrophage-derived interferon against encephalomyocarditis virus-induced diabetes mellitus in mice.

The involvement of macrophages in protection against diabetes mellitus in mice of BALB/c (susceptible) and C57BL (resistant) strains infected with the B (non-diabetogenic) or D (highly diabetogenic) variant of encephalomyocarditis (EMC) virus was examined. Pretreatment with the B variant of EMC virus (EMC-B), avirulent interferon (IFN) inducer, or Corynebacterium parvum inhibited diabetes in BALB/c mice infected with the D variant of EMC virus (EMC-D). Treatment of C57BL mice with carrageenan to compromise macrophage function rendered C57BL mice susceptible to EMC-D-induced diabetes. In macrophage culture for BALB/c mice, EMC-B induced IFN at an earlier stage than did EMC-D. The C57BL mouse-derived macrophages produced more IFN than did BALB/c mouse-derived macrophages after stimulation with EMC-D. Moreover, C. parvum increased IFN production in macrophage cultures from BALB/c mice, whereas carrageenan inhibited that in macrophage cultures from C57BL mice. These results suggest that IFN derived from macrophages may have an important role in protecting mice against EMC virus infection.

Animals↗

PubMed1994

Differential Na+,K(+)-ATPase activity and cisplatin sensitivity between transformants induced by H-ras and those induced by K-ras.

We examined the differential effects of the H-ras oncogene and the K-ras oncogene on cisplatin sensitivity in murine NIH/3T3 cells transfected with these oncogenes. Although the NIH/3T3 cells transformed with H-ras oncogenes (EJ-NIH/3T3 and Ha8-21) showed an increased resistance to cisplatin compared to the parental NIH/3T3, the cell lines transformed with K-ras oncogenes (DT and 1,8DNP2-2-5) did not. Compared with NIH/3T3, the 2 H-ras transformants reduced both the accumulation of cisplatin and the Na+,K(+)-ATPase activity in the membrane fraction. On the other hand, we observed no significant difference in cellular accumulation of cisplatin or in Na+,K(+)-ATPase activity between parental NIH/3T3 and the K-ras transformants. Since these ras transformants did not affect the cellular metallothionein content, transcriptional level of DNA polymerase beta or activity of glutathione-S-transferase which is not associated with cisplatin sensitivity, these results suggest that cisplatin resistance is brought about by the H-ras oncogene, but not by K-ras, and that induction of cisplatin resistance by H-ras is mainly due to a reduction of cisplatin accumulation and an impairment of Na+,K(+)-ATPase activity in the membrane fraction.

3T3 Cells↗

PubMed1994

Induction of apoptosis by a dominant negative H-RAS mutant (116Y) in K562 cells.

Recent extensive work on apoptosis has begun to reveal its molecular mechanisms. Several genes that regulate apoptosis have been identified. Among them, the BCL2 gene is considered to be an important gene that inhibits apoptosis. However, there must be other genes, yet to be identified, which suppress apoptosis. It has been suggested that the activation of RAS function by BCR-ABL fusion protein in chronic myelogenous leukemia may be an important mechanism in the BCR-ABL mediated transformation. Therefore, in this study we have investigated whether the suppression of endogenous H-RAS function inhibits the BCR-ABL mediated transforming activity in a K562 human chronic myelogenous leukemia cell line. The induced expression of a dominant negative v-H-RAS mutant (116Y) in K562 cells has resulted in cell death. The morphological characteristics and the detection of fragmented DNA by gel electrophoresis in the dead cells have revealed that this cell death is apoptosis. These results directly indicate that the RAS gene as well as the BCL2 gene has an ability to suppress apoptosis.

Apoptosis↗

PubMed1994

Suppression of various human tumor cell lines by a dominant negative H-ras mutant.

A dominant negative H-ras mutant, N116Y, was transfected into a variety of human tumor cell lines. N116Y extremely inhibited the proliferation of A431 (vulva), PC3 (prostate), T24 (bladder), MCF7 (breast), NKPS and TMK1 (stomach) cancer cell lines. A431 and PC3 cells were particularly susceptible to N116Y. In order to examine the effects of N116Y on the neoplastic phenotypes, we transfected a less efficient N116Y expression vector into A431 cells. Almost all clones survived after G418 selection. However, they did not retain the N116Y gene and only one clone faintly expressed N116Y. This N116Y-expressing clone had no tumorigenicity in vivo, and revealed deformed morphology and DNA fragmentation, suggesting that N116Y might have induced apoptotic cell death. Thus, N116Y may be applicable for gene therapy of a wide spectrum of human tumors.

Apoptosis↗

PubMed1993

Biological activity of a K-ras mutant that contains the 12R/59T/116Y mutations.

The 12R/59T/116Y mutations have been shown to confer a dominant negative activity on H-ras oncogene (H-ras 116Y). To determine whether this event is unique for H-ras, we introduced the same mutations into K-ras oncogene. This mutant, K-ras 116Y, suppressed transformed phenotypes induced by overexpression of H-ras proto-oncogene. NIH3T3 cells expressing K-ras 116Y were resistant to transformation by v-fes oncogene. Analysis of chimaeras between H- and K-ras 116Y showed that the C-terminal variable region determines the level of suppressor activity. These results suggest that these mutations are applicable to other GDP/GTP binding proteins.

3T3 Cells↗

PubMed1993

Resistance of NIH3T3 cells to v-fes transformation induced by a dominant negative H-ras mutant.

NIH3T3 cells carrying a dominant negative H-ras mutant 116Y acquired resistance to transformation by some PTK oncogenes, i.e., v-fes, v-abl, and v-fms, but were sensitive to viral ras and serine threonine kinase oncogenes, v-raf and v-mos. One clone, designated 1-20, infected with v-fes (1-20 fes) exhibited flat morphology and anchorage-dependent cell growth, as did noninfected 1-20 cells. The 1-20 fes cells expressed v-fes oncogene and produced transforming viruses, although these levels were much lower than those in NIH3T3 cells infected with v-fes (NIH3T3 fes). v-fes mRNAs in NIH3T3 fes cells rapidly increased after infection, while accumulation of the v-fes transcripts in 1-20 fes cells was significantly prolonged. Total tyrosine phosphorylation in both NIH3T3 fes and 1-20 fes cells was correlated with the amounts of pp110v-fes. A few proteins were phosphorylated only in NIH3T3 fes but not in 1-20 fes cells. These results suggest that the cellular ras is involved in a signaling pathway from pp110v-fes and this signal stimulates v-fes expression. Inhibition of the ras function may down-regulate this pathway and result in resistance to transformation by v-fes.

3T3 Cells↗

PubMed1993

Psychotic symptoms in depression and borderline personality disorder.

The authors investigated the prevalence of psychotic symptoms in depression and borderline personality disorder employing the Diagnostic Interview for Borderlines. Clear-cut delusions and hallucinations were rare among the borderlines. However, derealization and depersonalization symptoms were common and were found to be prevalent as among depressives. The prevalence of these symptoms among patients with both borderline personality disorder and depression was similar to that among patients with only borderline personality disorder or depression. The relationship between depression and borderline personality disorder and the significance of psychotic symptoms in these disorders is discussed.

Adolescent↗

PubMed1993

Object images of eating disorder patients.

The authors investigated images held by eating disorder patients toward selected stimulus words using the semantic differential method. The concept "object image" was introduced here to designate the images which any person has about the mother, the father, etc. A comparison was made between 22 eating disorder patients with concurrent borderline personality disorder, 20 patients without borderline pathology, and 48 controls. The eating disorder patients were found to have a "weaker" image of "motherliness" and "womanliness" compared to the control group. Another characteristic of eating disorder patients was their unfavorable image of children. The authors also studied the images held by fathers and mothers. In the families with borderline patients, the discrepancies between what we term "object images" held by fathers, mothers, and daughters were conspicuous. The importance of a tripartite (daughter-mother-father) relationship in the psychopathology of eating disorder is discussed.

Adolescent↗

PubMed1993

Relationship between clinical symptoms and EEG findings in borderline personality disorder.

Borderline personality disorder (BPD) was diagnosed in female patients (N = 41) between the ages of 18 and 30 using the Diagnostic Interview for Borderline Patients (DIB) and DSM-III. Comparing the EEG findings of BPD (N = 18) and non-BPD (N = 21) groups, there were no EEG findings characteristic of BPD. We also assessed the relationship between the EEG findings and DIB items. Positive spikes appeared in patients with high scores for Impulse Action Patterns, while wave and spike phantoms were observed in patients with high scores for Interpersonal Relations. Dividing the patients into BPD and non-BPD groups, a similar tendency to that observed from an analysis of all patients was observed in the non-BPD group, but no such tendency was observed in the BPD group. The results suggest that BPD patients include those in whom vulnerability of cerebral function plays an important role in the development of these two clinical symptoms as well as those in whom vulnerability of cerebral function plays almost no pathogenic role.

Adult↗

PubMed1993

Cyclin G: a new mammalian cyclin with homology to fission yeast Cig1.

A new gene encoding a cyclin-like protein has been isolated from a rat fibroblast cDNA library by cross-hybridization with a mixture of c-src family proto-oncogene kinase domains as a probe. This putative cyclin, called cyclin G, contains a typical cyclin box at the N-terminus but no apparent 'destruction box' or 'PEST' sequence. Interestingly, in its C-terminus region, it has a sequence homologous with a tyrosine phosphorylation site of the epidermal growth factor receptor. Although this cyclin is phylogenetically related to HCS26 of Saccharomyces cerevisiae, it most resembles Cig1, a B-type cyclin, of Schizosaccharomyces pombe, which has been suggested to act at the G1/S phase of the cell cycle. Cyclin G mRNA is induced within 3 h after growth stimulation and remains elevated with no apparent cell cycle dependency, indicating its close association with growth stimuli but not with the cell cycle.

Amino Acid Sequence↗

PubMed1992

Pheochromocytomas and C-cell thyroid neoplasms in transgenic c-mos mice: a model for the human multiple endocrine neoplasia type 2 syndrome.

Transgenic mice carrying and expressing a mos protooncogene, linked to the Moloney murine sarcoma virus long terminal repeat, develop severe neurological defects and lens abnormalities. Here we report that after long latent periods, mice in three of four of these mos transgenic lines develop a high frequency of multicentric pheochromocytomas and/or medullary thyroid neoplasms. The pattern of tumor formation is remarkably similar to the human autosomal dominantly inherited neoplastic syndrome, multiple endocrine neoplasia type 2 (MEN 2), and tumors from these transgenic animals display the same neuroendocrine marker staining pattern as seen in MEN 2. The similarity between the tumor pathologies and presentation patterns of MEN 2 patients and mos transgenic mice suggests that they may arise through related pathways. The type of tumor presentation varies in a line-dependent manner indicating that there is interaction between the transgene and the genetic background. Moreover, when the non-tumor-bearing mos transgenic line is crossed to a different mouse background, the F1 offspring display the MEN 2 phenotype. These studies indicate that penetrance of the autosomal dominant mos transgenic phenotype is dependent on both integration site and background.

Adrenal Gland Neoplasms↗

PubMed1990

Elevated gelsolin and alpha-actin expression in a flat revertant R1 of Ha-ras oncogene-transformed NIH/3T3 cells.

Expressions of gelsolin and alpha-actin have been investigated in a revertant cell line R1 and compared with the parental human activated Ha-ras oncogene-transformed NIH/3T3 (EJ-NIH/3T3), untransformed NIH/3T3 and partially revertant R2 cells. Gelsolin mRNA expression was strongest in R1 cells, intermediate in R2 and NIH/3T3 cells, and low in EJ-NIH/3T3 cells. Southern blot analysis gave neither signs of gross rearrangements nor amplification of the gelsolin gene. alpha-actin mRNA expression was restored in R1 cells to the level of NIH/3T3 cells. In R2 and EJ-NIH/3T3 cell lines, no alpha-actin transcript was detected. High gelsolin expression and restoration of alpha-actin expression may be associated with the acquirement of flat morphology and ordered cell growth pattern, which imply loss of tumorigenicity of R1 cells.

Actins↗