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Biomedical subjects

Y Ogiso

Publications and source records attributed to Y Ogiso.

At least 55 records · Page 3Linked to original sources
PubMed1990

A specific protein, p92, detected in flat revertants derived from NIH/3T3 transformed by human activated c-Ha-ras oncogene.

Total proteins from a mouse embryo fibroblast cell line NIH/3T3, NIH/3T3 cells transformed by human activated c-Ha-ras (EJ-ras) oncogene (EJ-NIH/3T3), and the two flat revertant cell lines, R1 and R2, were analyzed by two-dimensional gel electrophoresis (IEF and NEPHGE). Several hundred polypeptides were resolved as seen by silver staining. Common alterations in four polypeptide spots were observed in the revertants when compared with NIH/3T3 and EJ-NIH/3T3 cells. In these alterations, a new polypeptide spot p92-5.7 (designated by molecular weight x 10(-3) and pI) was detected only in the revertants and not in NIH/3T3 and EJ-NIH/3T3 cells. Furthermore, the expression level of p92-5.7 seemed to be associated with the flat morphology and the reduced tumorigenicity of the revertants. Polypeptide p92-5.7 was also not detected in the total proteins extracted from BALB/3T3 cells, NIH Swiss mouse primary embryo fibroblasts, NRK (normal rat kidney) cells, and L6 (rat myoblast). Subcellular fractionation of total protein from R1 cells revealed that the p92-5.7 was present in the cytosol. Western blot analysis using an anti-gelsolin antibody demonstrated that the p92-5.7 might be a variant form of gelsolin which is thought to be an actin regulatory protein or a gelsolin-like polypeptide. These results may suggest that the expression of p92-5.7 detected only in the revertants is associated, at least in part, with the reversion. This may be the first demonstration of specific protein expression in the flat revertants.

Animals↗
PubMed1990

Epidermal growth factor receptor mRNA is not increased in psoriatic skin.

Poly(A)+mRNAs were purified from the skin sheets of five psoriatic patients and three healthy individuals, and mRNA expression of epidermal growth factor (EGF) receptor gene was studied by Northern-blot technique using a cDNA probe of the whole EGF-receptor gene. Both psoriatic and normal skin had 5.3-kb and 11.0-kb mRNAs of the EGF-receptor gene. There existed no clear differences in the mRNA levels between psoriasis and normal controls. Since Nanney et al. has reported an increased number of EGF-receptors in active lesions of psoriasis, it has been speculated that the production of EGF-receptors is not increased, but rather that the down-regulation may be decreased, in psoriatic skin, resulting in the increased number of EGF-receptors.

Actins↗
PubMed1990

trans-Dominant suppressor mutations of the H-ras oncogene.

Site-directed mutagenesis of the conserved sequence motifs of p21 generated a group of mutant p21s defective in GTP binding. Some of these mutants were highly transforming, whereas others were transformation defective. Among the latter group, we found two mutants, derived from the v-H-ras oncogene by substituting the asparagine-116 with tyrosine and isoleucine, that exhibited a trans-dominant activity of suppressing the transformed phenotype of NIH3T3 cells induced by a long terminal repeat-linked c-H-ras and a wild-type v-H-ras. They caused reduction of the colony-forming efficiency in soft agar (78% in c-ras-transformed cells; 55% in v-ras cells) and morphological reversion of ras transformants. Subclones of revertants expressed a great excess of mutant p21 relative to the c-ras p21 present in these cells. These mutants were not lethal to NIH3T3 cells. Apparently, defective proteins encoded by suppressor mutants sequestered vital targets for ras function. Suppressor mutants also induced morphological reversion of NIH3T3 cells transformed by src, fes/flp, sis, and fms oncogenes, suggesting that these oncogenes function upstream to ras in the signaling pathways. Cells transformed by mos and a chemical carcinogen were unaffected.

Animals↗
PubMed1989

Reduced DNase I sensitivity of the rearranged c-myc gene in somatic cell hybrids between murine plasmacytoma cells and fibroblasts.

In mouse plasmacytoma (MPC) S194, the rearranged c-myc gene was much more sensitive to DNase I digestion than the nonrearranged gene. The sensitivity of the rearranged c-myc was markedly reduced to the same extent as that of the nonrearranged one in hybrids between the MPC cells and the fibroblasts, but not in a hybrid between the MPC and the spleen cells. These results suggest that trans-acting factors in fibroblasts alter the DNase I-sensitive structure of the rearranged c-myc gene.

Animals↗
PubMed1989

Reduced induction of c-fos but not of c-myc expressions in a nontumorigenic revertant R1 of Ej-ras-transformed NIH/3T3 cells treated with 12-O-tetradecanoylphorbol-13-acetate (TPA).

It has been reported that both c-fos and c-myc mRNAs are induced in NIH/3T3 cells after 12-O-tetradecanoylphorbol-13-acetate (TPA) treatment. We have studied the effect of TPA on the expression of c-fos and c-myc in EJ-ras-transformed NIH/3T3 and its nontumorigenic flat revertant R1 cells. Although TPA treatment induces c-myc mRNA, as in the case of NIH/3T3 cells, the induced level of c-fos mRNA is greatly reduced not only in slow-growing EJ-ras-transformed NIH/3T3 but also in quiescent R1 cells. In addition, serum-induced c-fos expression is also reduced in EJ-ras-transformed NIH/3T3 and R1 cells. These observations suggest that the pathway from TPA to c-fos gene is different from that to c-myc gene and that the former pathway is down-regulated in association not with the transformed phenotype, but with EJ-ras expression, and it is possible that this reduced induction of c-fos is not specific to TPA.

Animals↗
PubMed1989

Resistance to oncogenic transformation in revertant R1 of human ras-transformed NIH 3T3 cells.

A flat revertant, R1, was isolated from human activated c-Ha-ras-1 (hu-ac-Ha-ras) gene-transformed NIH 3T3 cells (EJ-NIH 3T3) treated with mutagens. R1 contained unchanged transfected hu-ac-Ha-ras DNA and expressed high levels of hu-ac-Ha-ras-specific mRNA and p21 protein. Transfection experiments revealed that NIH 3T3 cells could be transformed by DNA from R1 cells but R1 cells could not be retransformed by Kirsten sarcoma virus, DNA from EJ-NIH 3T3 cells, hu-ac-Ha-ras, v-src, v-mos, simian virus 40 large T antigen, or polyomavirus middle T antigen. Somatic cell hybridization studies showed that R1 was not retransformed by fusion with NIH 3T3 cells and suppressed anchorage independence of EJ-NIH 3T3 and hu-ac-Ha-ras gene-transformed rat W31 cells in soft agar. These results suggest that the reversion and resistance to several oncogenes in R1 is due not to cellular defects in the production of the transformed phenotype but rather to enhancement of cellular mechanisms that suppress oncogenic transformation.

Animals↗
PubMed1988

Mechanism of O2- (-) and H2O2-induced stimulation of sugar transport in mouse fibroblast BALB/3T3 cells.

Xanthine/xanthine oxidase and H2O2 stimulated sugar transport. Application of superoxide dismutase and catalase to the cells showed an inhibitory effect on these agent-stimulated sugar transports. Addition of amiloride and 4-acetamide-4'-isothiocyanostilbene-2,2'-disulfonic acid (SITS), which abolish the cytoplasmic alkalinization, inhibited the stimulation of sugar transport by xanthine/xanthine oxidase in the presence of catalase. The calmodulin antagonists, N-(6-aminohexyl)-5-chloro-1-naphthalenesulfonamide (W-7) and trifluoperazine inhibited H2O2-stimulated sugar transport. These results suggest that O2- stimulates sugar transport in an intracellular pH-dependent manner and that H2O2 stimulates sugar transport in a calcium-calmodulin-dependent manner. These mechanisms may be involved in sugar-transport stimulation in mouse fibroblast BALB/3T3 cells by the tumor-promoting phorbol ester phorbol-12,13-dibutyrate and insulin, since the stimulatory effects of these agents were inhibited by scavengers of oxygen radicals.

4-Acetamido-4'-isothiocyanatostilbene-2,2'-disulfo↗
PubMed1988

c-myc expression and transformed phenotypes in hybrid clones between mouse plasmacytoma S194 cells and normal spleen cells or fibroblasts.

Expression of the rearranged c-myc oncogene and transformed phenotypes was investigated in 2 different types of somatic cell hybrid clones between a BALB/c mouse plasmacytoma line (S194) and normal allogeneic spleen cells or fibroblasts. In the parental S194 cells, one allele of the c-myc was rearranged and its 5'-flanking region was partially deleted by recombination with the immunoglobulin C alpha gene. Due to this recombination, S194 cells expressed approximately 20-fold higher than normal spleen or fibroblast levels of c-myc transcripts from the rearranged allele, which are smaller than normal germ-line 2.4-kb c-myc transcripts, but they expressed the same low levels of 2.4-kb c-myc transcripts from the non-rearranged allele as compared with normal spleen cells or fibroblasts. All the hybrid clones retained both the rearranged and the non-rearranged c-myc. The hybrid clones between S194 and normal spleen cells showed transformed phenotypes and expressed the same high levels of rearranged c-myc transcripts and low levels of the non-rearranged c-myc transcripts as the parental S194 cells. On the other hand, the hybrid clones between S194 cells and normal fibroblasts showing non-transformed phenotypes inhibited expression of the rear-ranged c-myc to undetectable levels but expressed the non-rearranged c-myc transcripts at low levels. A hybrid clone between S194 cells and normal fibroblasts showing transformed phenotypes also exhibited the same pattern of c-myc expression as the non-transformed hybrid clones. These results indicate that expression of the rearranged c-myc in S194 mouse plasmacytoma cells is modulated in different ways in different components of cell lineages, although the correlation between the levels of rearranged c-myc transcripts and the transformed phenotypes in the hybrid clones was not absolute.

Animals↗
PubMed1988

Changes of c-mos expression in response to 2-O-tetradecanoylphorbol-13-acetate in undifferentiated teratocarcinoma cells.

Treatment of the cells of the 311 cell line, a pluripotent mouse teratocarcinoma cell line, with 12-O-tetradecanoylphorbol-13-acetate (TPA) modulates c-mos expression. Transient suppression of 6.1 and 4.6 kilobases (kb) transcripts and activation of 1.8 transcript indicate that TPA mediates concurrently positive and negative regulation of c-mos transcription. The results show that the c-mos gene is a TPA-modulated gene. In addition, a TPA-responsive element (GTGACTCA), which exists in the 5'-flanking region of c-mos gene of Balb/c mice [1,2], is suggested to be involved in this response. However, these changes were not accompanied by early marker changes associated with endodermal cell differentiation, i.e., morphological change, induction of plasminogen activator and suppression of glucose transport activity.

3-O-Methylglucose↗
PubMed1988

Enhanced expression of ras gene products in psoriatic epidermis.

The ras oncogene product ras p21 is structurally homologous to guanine nucleotide-binding proteins and plays an important role in transducing signals elicited by membrane receptors into intracellular metabolism. We examined psoriatic tissues for expression of ras p21 and compared them with normal skin, using the indirect immunofluorescence technique with the anti-ras p21 monoclonal antibody (MoAb), rp-35. In normal epidermis of five healthy individuals and uninvolved epidermis of three psoriatic patients, only the basal layer was positively stained by rp-35. The spinous layer was negative or faintly positive. In contrast, all psoriatic epidermis obtained from 13 psoriatic patients had strong reactivity with rp-35 throughout the epidermis. There were no differences in the staining pattern of hair follicles, sebaceous glands, eccrine glands, and eccrine ducts, which positively reacted with rp-35, between psoriatic and normal skin. The functions of ras p21 have not been clearly identified in mammalian cells; however recent reports reveal that cyclic AMP production is inhibited by the transfection of activated ras gene into normal cells. Enhanced expression of ras p21 in psoriatic epidermis may be indicative of some mechanism of defective beta-adrenergic responsiveness, which is considered to be one of the important pathophysiological phenomena causing the hyperproliferative condition in psoriasis.

Antibodies, Monoclonal↗
PubMed1988

Expression of proto-oncogenes in normal and tumor tissues of human skin.

The expression of c-fos, c-myc, Ha-ras, N-ras, EGF-receptor, and cardiac actin genes was examined in 7 normal epidermis, 3 cellular nevi, and 8 skin tumors including 6 malignant and 2 benign tumors of human origin. These genes were transcribed in most normal and tumor tissues, though no tumor-specific expression of proto-oncogenes (c-fos, c-myc, Ha-ras, and N-ras) could be detected. However, there was a characteristic parallelism between the expression of c-fos and c-myc in normal epidermis, while the parallelism was not always definite in skin tumors. The ratio of c-fos/c-myc transcripts in normal epidermis was constant compared with the expression of other genes examined. These data suggest that c-fos and c-myc are expressed in all normal skin tissues, and that maintenance of a constant ratio of c-fos/c-myc is closely related to ordered cell growth of the tissues.

Cell Division↗
PubMed1988

[A study on reversion of the human activated c-Ha-ras-transformed cells].

Two mutant cell lines, R-1 and R-2, have been isolated from EJ/NIH (NIH/3T3 transformed by a human activated c-Ha-ras gene) by treatment with ethyl-methane-sulfonate (EMS). They reveal various characteristics of normal cells, and seem to have reversed to the original cells. Especially, R-1 shows a very flat morphology, complete contact inhibition, anchorage dependent cell growth and no tumorigenecity. Although transformed phenotypes are intensively suppressed, R-1 does not seem to secrete suppressive factors to the parent cell line. The activated c-Ha-ras (EJ-ras) could be detected as a 6.6 kb BamHI fragment in R-1 as well as in EJ/NIH. The level of transcription and translation in R-1 was also the same as that in EJ/NIH. Moreover, the DNA isolated from R-1 cells had a high transforming activity to NIH/3H3, suggesting that R-1 contained the EJ-ras as an activated oncogene. The levels of transcription of c-myc, c-fos, p53 and other ras family genes was unchanged between EJ/NIH and R-1. Further, R-1 cells are resistant to retransformation by EJ-ras, v-src, v-mos and SV40T genes, and DNAs isolated from EJ/NIH or NIH/3T3 could not transform R-1 cells. All these findings suggest that some genes necessary for transformation by EJ-ras, except for c-myc, c-fos, p53 and ras proto-oncogenes, are defective or some inhibitory genes against transformation are enhanced in R-1 cells.

Animals↗
PubMed1987

Inhibition by pertussis toxin of fibroblast growth factor-stimulated hexose transport in Swiss 3T3 cells.

Addition of fibroblast growth factor to quiescent cultures of Swiss 3T3 cells stimulated the membrane transport of 2-deoxyglucose. Treatment of the cells with pertussis toxin (islet-activating protein) inhibited fibroblast growth factor-stimulated hexose transport. 5'-Guanylyl imidodiphosphate (p[NH]ppG), a non hydrolyzable analogue of GTP, increased the number of hexose carriers in the plasma membrane of saponin-permeabilized cells. These results suggest that guanine nucleotide binding protein may be involved in the regulation of hexose transport system by fibroblast growth factor in Swiss 3T3 cells.

Affinity Labels↗
PubMed1987

Suppression of c-mos expression in teratocarcinoma cells with a new type of inducer of differentiation, 3,5-di-tert-butylchalcone 4'-carboxylic acid.

The treatment of 311 cells, a pluripotent mouse teratocarcinoma cell line, with a new type of inducer, 3,5-di-tert-butylchalcone 4'-carboxylic acid (Ch55), results in the suppression of the c-mos gene, accompanied by early marker changes associated with cell differentiation, i.e., the enhanced secretion of plasminogen activator and the decrease in peanut agglutinin receptors and glucose transport. This indicates that Ch55 is a potent inducer of teratocarcinoma cells and suppresses c-mos expression.

3-O-Methylglucose↗
PubMed1987

Unresponsiveness of both non-rearranged and rearranged c-myc to serum stimulation in a mouse plasmacytoma S194.

Expression of non-rearranged and rearranged c-myc in a mouse plasmacytoma cell line S194 cultured in different serum concentration or temperature was examined. Exponentially growing S194 cells expressed a high level of rearranged c-myc and a low level of non-rearranged c-myc mRNAs. The levels of the two c-myc mRNAs were nearly the same in the cells in which growth was suppressed by lowering serum concentrations or incubation temperature in culture medium. Furthermore, even when serum-deprived S194 cells resumed growth following serum restimulation, the induction of non-rearranged c-myc mRNA, observed in a mouse T-cell lymphoma cell line BW5147, was not demonstrated. In contrast to the unchanged c-myc expression, the level of N-ras mRNA was related to changes in cell growth rate induced by changes in serum concentration in S194 cells. These results suggest that not only the rearranged c-myc but also the non-rearranged c-myc is unresponsive to serum stimulation and temperature changes, even though cell growth rate is markedly changed.

Animals↗
PubMed1987

Possible involvement of a Na+/H+ antiporter in the stimulation of hexose transport in Swiss 3T3 cells by a phorbol ester and growth factors.

Phorbol-12,13-dibutyrate, epidermal growth factor, and insulin raised the intracellular pH ([pH]i), presumably through the activation of a Na+/H+ antiporter. Addition of amiloride or replacement of extra-cellular Na+ by choline which abolishes the cytoplasmic alkalinization prevented the stimulation of hexose transport by these agents. Furthermore, monensin, a Na+/H+ ionophore which increases the [pH]i, stimulated hexose transport. This stimulation was also prevented by the replacement of extra-cellular Na+ by choline. These observations suggest that stimulation of the Na+/H+ antiporter may have stimulated the increase in hexose transport.

Amiloride↗