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K Kiguchi

Publications and source records attributed to K Kiguchi.

69 records · Page 4Linked to original sources
PubMed1990

Genistein-induced cell differentiation and protein-linked DNA strand breakage in human melanoma cells.

Genistein, an in vitro inhibitor of topoisomerase II and tyrosine kinases, elicited an inhibition of growth and increased melanin content in five human melanoma cell lines, after six days of treatment at a concentration of 45 microM. In two lines examined more thoroughly, HO and SK-MEL-131, treatment with genistein also increased other markers of differentiation, including tyrosinase activity, reactivity with CF21 monoclonal antibody, and dendrite-like structure formation. The genistein-evoked increases in melanin content and tyrosinase activity were concentration- and time-dependent. Treatment of HO and SK-MEL-131 cells with 45 microM genistein for 24 hr or 60-600 microM genistein for only 1 hr resulted in an increase in protein-linked DNA strand breaks. Our results suggest an association between the genistein-evoked, protein-linked, DNA strand breaks and the genistein-induced differentiation of human melanoma cells.

Antibodies, Monoclonal↗
PubMed1990

Induction of cell differentiation in melanoma cells by inhibitors of IMP dehydrogenase: altered patterns of IMP dehydrogenase expression and activity.

To study the induction of differentiation in human melanoma cells, we treated 12 melanoma cell lines with mycophenolic acid and tiazofurin, inhibitors of IMP dehydrogenase (IMPDH). In all cell lines studied, both agents inhibited cell growth and increased melanin content. However, the degree of growth inhibition did not necessarily correspond to the increase in melanin content. A detailed analysis of the HO and SK-MEL-131 cell lines indicated that mycophenolic acid and tiazofurin caused a time- and dose-dependent increase in the expression of a series of other maturation markers, including formation of dendrite-like structures, tyrosinase activity, and reactivity with the CF21 monoclonal antibody. The growth inhibition and melanogenesis induced by the IMPDH inhibitors was abrogated by the addition of exogenous guanosine. No such effect was observed after treatment of the cells with phorbol 12-myristate 13-acetate or retinoic acid, two other inducers of differentiation in these cells. The mycophenolic acid- and tiazofurin-treated cells also showed an increased level of IMPDH mRNA and protein, perhaps because of compensation for the inhibitor-mediated decrease in IMPDH activity. In contrast, treatment with phorbol 12-myristate 13-acetate or retinoic acid resulted in decreased levels of IMPDH mRNA and protein. The lack of a consistent pattern of IMPDH expression in the cells treated with IMPDH inhibitors and phorbol 12-myristate 13-acetate or retinoic acid suggests that the altered expression of IMPDH is not a general requirement for the induction of cell differentiation in these cells. Our results also suggest that IMPDH inhibitors may provide a useful approach to circumvent the differentiation block in melanoma.

Biomarkers↗
PubMed1990

[Establishment and characterization of a human chorionic gonadotropin (hCG) producing cell line (RTSG) from an ovarian epithelial cancer].

A new cell line designated RTSG established in vitro from the pleural effusion of a patient with metastatic ovarian epithelial cancer has been subcultured 46 times for more than 2 years. The cells grew in a monolayered sheet, showing a tendency to pile up, with the population doubling in 48 hrs. Electron-microscopically, desmosomes were characteristically observed, suggesting the cells were of epithelial origin. Chromosomal analysis revealed aneuploidy with a tetraploid mode. The heterotransplanted tumors in nude mice were histopathologically classified as a poorly differentiated adenocarcinoma, whereas the original tumor consisted mainly of mucinous and serous cystadenocarcinoma and only partly of poorly differentiated adenocarcinoma. The cells secreted hCG (38.8 mIU/day/10(6) cells) and beta-hCG (6.1 ng/day/10(6) cells) in spent medium. Immunocytologic +-and-histochemical staining for tumor markers of the original tumor, the cultured cells and the transplanted tumors also revealed the localization of not only hCG and beta-hCG but also CA19-9 and CA-125 whose values had been elevated in the preoperative serum (hCG: 10 mIU/ml, CA19-9: 6,400 U/ml, CA-125: 225 U/ml). Results of PAS, Alcian-blue and Mucicarmine strains indicated that most of the PAS-positive substances in the cultured cells and the transplanted tumors were consistent with glycogen while the original tumor mainly contained mucin except for the lesion of poorly differentiated adenocarcinoma with glycogen. These results suggested that the cultured cells might originate from poorly differentiated adenocarcinoma cells in the original tumor.

Adenocarcinoma↗
PubMed1989

[Galactosyltransferase isozyme II (GT-II) as a new tumor marker for ovarian cancers--especially for clear cell carcinoma].

Serum levels of galactosyltransferase (GT) and its isozyme (GT-II), which transfers galactose from UDP-galactose to N-acetylglucosamine etc., in gynecologic malignancies, were assayed. GT activity was assayed with UDP-[3H] galactose and ovalbumin as substrate, and GT-II was assayed by selectively removing GT-II from serum by immunoabsorption with immobilized monoclonal antibody 3872, followed by assay of bound GT activity. GT was not specific for cancer, but GT-II was positive in 74% of the ovarian cancer patients, and remarkably high serum levels were observed in mesonephroid cancers, indicating its possible usefulness as a new tumor marker. Immunohistochemical staining revealed that GT-II was localized on the cell surface and in the cytoplasm, suggesting its production by tumor cells.

Adenocarcinoma↗
PubMed1989

[The evaluation of CA54/61 in the diagnosis of ovarian cancer--with special reference to the cooperative results of 5 institutes].

The clinical usefulness of a newly developed one-step enzyme-immunoassay, MKS-15, in the diagnosis of ovarian cancer was evaluated with 1,563 serum samples collected at five institutes. In this assay, two monoclonal antibodies, MA54 and MA61, which both recognize the carbohydrate chain in a high molecular weight mucin-type glycoprotein, were used as the immobilized antibody on beads and peroxidase-labeled antibody, respectively. When the cut-off value was set at 20 IU/ml (mean + 3SD), 56% of the sera from ovarian cancer patients were positive, and the positive rates for serous, mucinous, mesonephroid, endometrioid, undifferentiated, and metastatic cancers were 63%, 55%, 52%, 38%, 55%, and 62%, respectively. In sera from patients with benign ovarian tumors, only 4% of the cases were positive, but 7% of benign and low potential malignant cases of mucinous cystadenoma were positive, indicating that CA54/61 cannot distinguish benign mucinous cystadenoma from malignant ones. Since the positive rate for CA125 is rather low in mucinous cyst-adenocarcinoma, CA54/61 may be of clinical value.

Adolescent↗
PubMed1986

Gangliosides as markers of cortisone-sensitive and cortisone-resistant rabbit thymocytes: characterization of thymus-specific gangliosides and preferential changes of particular gangliosides in the thymus of cortisone-treated rabbits.

Neutral glycosphingolipids and gangliosides in rabbit thymus, spleen, bone marrow, and erythrocyte ghosts were analyzed by conventional chemical and enzymatic procedures and negative ion fast atom bombardment mass spectrometry (FABMS). Thymus gangliosides showed a characteristic composition. Major gangliosides comprising 75% of the total thymus gangliosides were sialosyl lacto-N-neo-tetraosyl- and sialosyl lacto-N-nor-hexaosylceramides containing NeuGc and palmitic acid. These major thymus gangliosides were not detected in spleen, bone marrow, or erythrocytes, whereas GD1a, which was not present in the thymus even in a trace amount, was present in spleen and bone marrow. In addition, the major gangliosides in rabbit thymus were preferentially reduced when an animal was given an intraperitoneal injection of cortisone acetate, as found on analysis 48 h later. The decrease was accompanied by a concomitant increase in NeuAc-containing GM3 with longer chain fatty acids.

Animals↗
PubMed1986

Alteration in glycosphingolipid pattern during phorbol-12-myristate-13-acetate-induced cell differentiation in human T-lymphoid leukemia cells.

We analyzed the patterns of glycosphingolipids (GSLs) from a line of cells derived from a clone of the human T-cell leukemia cells (CEM) that had been induced to differentiate by phorbol-12-myristate-13-acetate (PMA) into cells with a suppressor-like phenotype. We characterized the differentiation state of the cells by immunofluorescence by using anti-cell surface differentiation-specific monoclonal antibodies (OKT3, OKT4, OKT6, and OKT8). The GSLs were extracted and separated by thin-layer chromatography and the individual bands were quantitated by a dual-wavelength densitometer or by autoradiography of GSLs labeled with [14C]glucosamine and [14C]galactose. Treatment of the CEM cells with 0.16-16 nM PMA for 6 h to 6 days resulted in a dose- and time-dependent increase in the amount of two neutral GSLs [ceramide monohexoside and ceramide dihexoside] and three gangliosides [monosialoganglioside (GM3), sialosylparagloboside, and disialoganglioside (GD3)]. The increase in the neutral GSLs after PMA treatment reached its maximum at 30 h while GM3 peaked at 96 h. The increases in GM3 and sialosylparagloboside are presumably due to an increase in their synthesis levels because PMA promoted an elevated incorporation of glucosamine and galactose into these GSLs. The increase in the amount of GD3, on the other hand, is due to either a decrease in its degradation or use in other metabolic pathways because no detectable increase in glucosamine and galactose incorporation into this ganglioside could be found. Incubation of control or PMA-induced CEM cells with GM3 fractions purified from either CEM cells, human brain, or dog erythrocytes caused a reduction in cell growth and prevented the increase in reactivity of the induced cells with the OKT3 antibody. Incubation with semisynthetic ceramide dihexoside, however, prevented the decrease in reactivity with the OKT4 antibody. The observed changes in GSL patterns during PMA-induced differentiation of the CEM cells into suppressor-like cells and the inhibition of CEM cell growth by GM3 fractions suggest that the GSLs play a role in the control of cell growth and differentiation in the PMA-treated CEM cells.

Antibodies, Monoclonal↗
PubMed1985

Rabbit thymus gangliosides: species- and organ-specific distribution, age-dependence and their cell biological significance.

Gangliosides of thymuses from rabbit, mouse, rat, calf, and man were analyzed. The ganglioside compositions of the thymuses showed species specificities, and the compositions of the species other than the rabbit were found to be markedly different from that of the rabbit, which contained characteristically substantial amounts of IV3NeuGc-nLc4Cer and VI3NeuGc-nLc6Cer (Iwamori, M. & Nagai, Y. (1981) Biochim. Biophys. Acta 665, 214-220). The inter-species differences in the thymus ganglioside compositions were not remarkable in the 8 mouse and 2 rabbit strains examined. Rabbit thymocytes, but not those of mouse and rat, were lysed with human Hanganutziu-Deicher serum in the presence of guinea pig complement, reflecting the high content of gangliosides containing N-glycolylneuraminic acid in rabbit thymus. As to age-dependent changes of gangliosides in rabbit thymus and spleen, the concentrations gradually decreased with age, while the molar ratio of total gangliosides to total phospholipids was constant in the spleen throughout life and in the thymus at 3, 4, and 6 weeks of age. It was noted that old (180 weeks of age) rabbit thymus, which is occupied largely by fat tissue, still contained a significant amount of neolactoseries gangliosides.

Age Factors↗
PubMed1983

Characterization of glycosphingolipids from cells of various types of human leukemia: occurrence of two glycosphingolipids, one reacting with anti-asialo GM1 antibody and one with anti-Forssman antibody.

Glycosphingolipids of neutrophils, lymphocytes and leukocytes from patients with various types of human leukemia [acute lymphoblastic (ALL), acute unclassified type (AUL), acute myeloblastic (AML), acute monocytic (AMoL), chronic myeloblastic (CML)] and the hypereosinophilic syndrome (HES) were analyzed chemically and immunochemically. No distinct difference was found in the molar ratio of lipid-bound sialic acid to lipid-bound phosphorus in these cells, but a low ratio of cholesterol to lipid-bound phosphorus was found in ALL (3 of 4 cases), AML, CML and AMoL (one of 2 cases). The predominant glycosphingolipid was ceramide dihexoside (CDH) in all cells analyzed, but the amount and the molar ratio of lipid-bound phosphorus to CDH were clearly different in different cell types, indicating that the molar ratio is a useful criterion in the classification of types of leukemia. In addition, molecular diversity of minor glycosphingolipid components was observed in various leukemic cells. Two of the neutral glycosphingolipids in AMoL were tentatively identified as asialo GM1 and Forssman glycolipids by comparing their mobilities on thin-layer chromatography with those of standard glycolipids and by observing the formation of precipitin lines on a double diffusion agar plate with anti-asialo GM1 and anti-Forssman antibodies.

G(M1) Ganglioside↗
PubMed1981

Dysplasia during pregnancy: a cytologic follow-up study.

To clarify the characteristics of dysplasia in the pregnant state, 525 of 703 dysplasias in pregnant women recorded in the laboratory computer at the University of Chicago Lying-in Hospital during a ten-year period were selected for study through medical records. These materials were basically diagnosed by cytologic techniques. The regression rates of moderate and marked dysplasia within a six-month period after delivery seemed to be much higher than those of dysplasia in the general population. The progression rates of dysplasia to carcinoma in situ during pregnancy and after delivery were almost the same as those of dysplasia in the nonpregnant state, whereas the progression rate of dysplasia to invasive carcinoma after delivery (0.4%) was almost half that in the nonpregnant state (1%). With reference to the latent period during which dysplasia progressed to malignancy, dysplastic lesions during pregnancy, as compared to those in nongravid women, had a higher potential for progression. The number of dysplastic cells decreased with the course of pregnancy. The rates of metaplastic and keratinizing types of dysplasia were remarkably higher than those in the general population, and the rates of those types of dysplasias increased with the course of pregnancy.

Adolescent↗
PubMed1978

Effects of macromolecular compounds on human leukocyte beta-galactosidase activity.

The enzyme properties of leukocyte beta-galactosidase and the effects of macromolecular compounds on its activity were studied in detail. It was demonstrated that various macromolecular compounds markedly influence the activity of beta-galactosidase. These phenomena should be taken into account when considering the biochemical abnormalities of tissues of patients with mucopolysaccharidoses and mucolipidoses.

Chromatography, Gel↗
PubMedDate not supplied

Correlations between topological resonance energy of methyl-substituted benz[c]acridines, benzo[a]phenothiazines and chrysenes, and their carcinogenic or antitumor activities.

In order to clarify the effects of methyl substitution on the carcinogenic activity, each resonance energy (RE) of benz[c]acridines, benzo[a]phenothiazines, chrysene, and their methyl derivatives was calculated by Aihara's TRE theory. Some correlations seem to exist between the values of resonance energy per pi-electron for the cationic species-with the lack of the atom having the highest approximate superdelocalizability (Sr'(E)) from their parents skeleton-and carcinogenic activity.

Acridines↗