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T Taki

Publications and source records attributed to T Taki.

At least 19 recordsLinked to original sources
PubMed1992

Human hepatoma gangliosides: occurrence of a novel I-type glycolipid with NeuAc alpha 2-6Gal structure.

Gangliosides with NeuAc alpha 2-6Gal structure have been studied in human hepatocellular carcinoma. The gangliosides were purified to homogeneity by a DEAE-Sephadex A-25 column chromatography and by repeated silica beads column chromatography. Three gangliosides containing NeuAc alpha 2-6Gal structure were isolated and were structurally characterized by using monoclonal antibodies, proton nuclear magnetic resonance, fast atom bombardment mass spectrometry, methylation analysis by gas chromatography-mass spectrometry, and exoglycosidase treatments. The first compound was identified as NeuAc alpha 2-6Gal beta 1-4GlcNAc beta 1-3Gal beta 1-4Glc beta 1-1Cer. The structures of 2 other components were concluded to be as follows: [formula: see text] The first compound is a ganglioside that is characteristic of human meconium. The second compound has the same structure as a ganglioside recently found by us (Taki, T., Rokukawa, C., Kasama, T., Kon, K., Ando, S., Abe, T., and Handa, S., J. Biol. Chem., 267: 11811-11817, 1992) in meconium. The third compound is a novel type of ganglioside having blood group I-type structure as the core sequence. In addition to these gangliosides, 5 others were detected, and all except for GM3 were glycolipids with neolacto-series core structure. These results suggest that enzymes for the synthesis of neolacto type and NeuAc alpha 2-6Gal structure of glycolipids are activated in hepatoma.

Antibodies, Monoclonal↗
PubMed1992

Correlation of expression of H/Le(y)/Le(b) antigens with survival in patients with carcinoma of the lung.

BACKGROUND: The level of expression of H/Le(y)/Le(b) antigens is high in various histologic types of lung cancer, a feature that may be related to deletion of A and B blood-group antigens. We evaluated the possibility that expression of this antigen, which can be defined by the monoclonal antibody MIA-15-5, might be of prognostic value, as suggested by our previous observation that MIA-15-5 inhibits tumor-cell motility and metastasis. METHODS: We used MIA-15-5 to stain tissue sections from 149 patients with primary lung cancer whose clinico-pathological histories were well documented. The survival curves for patients whose tumors stained positively were compared with the curves for those whose tumors stained negatively. Multivariate analyses were performed with a Cox proportional-hazards regression model. RESULTS: Among the 149 patients studied, five-year survival in the 91 patients with MIA-positive tumors was significantly lower than survival in the 58 with MIA-negative tumors (20.9 percent vs. 58.6 percent, P less than 0.001). Among the 67 patients with squamous-cell carcinoma, the rates also differed significantly (10.5 percent vs. 62.1 percent, P less than 0.001). The difference in survival between patients with MIA-positive tumors and those with MIA-negative tumors was significant among patients with blood groups A and AB (P less than 0.001), but not among those with blood group B or O (P = 0.071 and 0.068, respectively). Multivariate analysis with the Cox regression model indicated that positivity best correlated with five-year mortality, followed by lymph-node status (N stage) and tumor size status (T stage), whereas sex, age, and blood group did not correlate with mortality. CONCLUSIONS: Positivity for MIA (i.e., immunohistologic staining by MIA-15-5, which defines H/Le(y)/Le(b) antigens) is inversely correlated with survival among patients with primary lung cancer and may be of prognostic value.

ABO Blood-Group System↗
PubMed1992

Human meconium gangliosides. Characterization of a novel I-type ganglioside with the NeuAc alpha 2-6Gal structure.

Three monosialogangliosides containing the NeuAc alpha 2-6Gal structure have been detected in human meconium by immunological analysis using a monoclonal antibody, MSG-15, and purified by repeated silica beads column chromatography. One was previously shown to be NeuAc alpha 2-6Gal beta 1-4GlcNAc beta 1-3Gal beta 1-4Glc beta 1-1Cer. The remaining two were characterized by proton NMR, fast atom bombardment mass spectrometry, methylation analysis by gas chromatography-mass spectrometry, and immunological studies, and their structures were concluded to be as follows. [formula: see text] The second ganglioside has the same structure that was isolated from bovine buttermilk (Takamizawa, K., Iwamori, M., Mutai, M., and Nagai, Y. (1986) J. Biol. Chem. 261, 5625-5630), and this is the first description of the occurrence of the ganglioside with the branched structure with two N-acetyllactosamines linked to lactosylceramide via beta 1-6 and beta 1-3 in human linked to lactosylceramide via beta 1-6 and beta 1-3 in human tissues. The third ganglioside is a novel ganglioside with blood group I-type and a NeuAc alpha 2-6Gal structure.

Amino Sugars↗
PubMed1992

First establishment of a human monoclonal antibody directed to sulfated glycosphingolipids SM4s-Gal and SM4g, from a patient with lung cancer.

Several human monoclonal antibodies directed to tumor-associated glycolipid antigens have been established, but more than one-half of them react with gangliosides and the others react with neutral glycolipids. We report here the first establishment of a human IgM monoclonal antibody directed to the sulfated glycolipid. This monoclonal antibody, M14-376, did not react with SM3 and SB1a which have a terminal HSO3----3Gal beta 1----R1, but with the simple sulfolipids SM4s-Gal and SM4g which contain a terminal HSO3----3Gal beta 1----O----CH2----R2; however, lyso-SM4s-Gal and lyso-SM4g did not bind M14-376. These results suggest that terminal HSO3----3Gal and part of the hydrophobic region of the glycolipid are recognized by M14-376. Directly biotinylated M14-376 was used for immunohistochemical staining of 140 formalin-fixed, paraffin-embedded lung cancer tissue sections to study the distribution of the antigen. A high incidence of positive staining was found in adenocarcinoma (39.5%, 17 of 43), followed by large cell carcinoma (20.0%, 5 of 25), while this antigen was rarely detected in small cell carcinoma (4.7%, 1 of 21) and squamous cell carcinoma (3.9%, 2 of 51). Thin layer chromatography immunostaining of glycolipids extracted from lung cancer tissues showed the presence of only SM4s-Gal in adenocarcinoma, but SM4g was not found in any subtype of lung cancer. Immunohistochemical staining revealed that this antigen was expressed in normal kidney, testis, and brain, but erythrocytes, granulocytes, and lymphocytes were negative in cytofluorometric analysis.

Adenocarcinoma↗
PubMed1992

Elevation of 4 beta-galactosyltransferase activity for paragloboside synthesis in sera of patients with cancer.

Galactosyltransferase activities in sera of cancer patients were determined by assaying the formation of paragloboside from UDP-galactose and lactotriaosylceramide immobilized on microtiter plates by means of the enzyme-linked immunosorbent assay using a monoclonal antibody, H-11, directed to paragloboside. Enzyme properties were as follows. Optimum pH was 6.8 in cacodylate buffer, and Km values were 2 microM for lactotriaosylceramide and 29 microM for UDP-galactose. The enzyme activity was inhibited by the addition of alpha-lactalbumin. Glucose (20 mM) inhibited the enzyme activity in the presence of alpha-lactalbumin (0.1 mg/ml) but not in its absence. These enzyme properties are similar to those of bovine milk galactosyltransferase, indicating that the enzyme in the sera might be lactose synthetase. The enzyme activities in sera from patients with cancer, patients with benign disease, or a reference sample group were assayed. The activity was below the limit of detection (5.5 pmol/25 microliters serum/2 h) in the reference sample group. Remarkable elevations of the enzyme activity were observed with high incidence in patients with cancer, especially those with blood cancer (100%). A high incidence was observed in the progressive stage, and the enzyme activity was detected at stage 1 in lung, esophagus, stomach, colorectal, and testis cancer. The enzyme activity in sera from patients with benign disease was elevated in 22% of the patients. After effective therapies, the enzyme activity decreased to below the limit of detection. Release of the galactosyltransferase into culture medium of cancer cells could be demonstrated. These observations suggest that the galactosyltransferase is released from cancer tissue into the circulation. The present method for the assay of galactosyltransferase may be useful for the detection of patients with cancer and for monitoring neoplastic recurrence after therapy.

Antibodies, Monoclonal↗
PubMed1992

Immunohistochemical demonstration of glycoconjugates bearing the type 2 chain-backbone structure in human fetal, normal and neoplastic gastrointestinal tract.

Immunohistochemical distributions of carbohydrate antigens based on the type 2 chain in normal as well as fetal and neoplastic tissues of human gastrointestinal tract were investigated with a monoclonal antibody (MAb) H11 (specific for type 2 chain) alone and in combination with the two MAbs MSG15 (for alpha 2----6 sialylated type 2 chain) and IB9 (for the alpha 2----6 sialylated type 2 chain and glycoproteins having NeuAc alpha 2----6Gal-NAc), and 188C1 (for short- and long-chain Lex antigens) and FH2 (for the long-chain Lex antigen). In the pyloric mucosa of secretors, the type 2 chain is oncodevelopmentally expressed, but in non-secretors it is detected in surface mucous cells of normal gastric mucosa. The alpha 2----6 sialylation, which is confined to endocrine cells of normal pyloric mucosa, occurs in fetal and carcinoma tissues. Irrespective of the secretor status, the short- and the long-chain Lex antigens can be detected in mature and immature glandular mucous cells of normal gastric mucosa, respectively; both antigens are also expressed in fetal and carcinoma tissues. In the colon, the type 2 chain and its alpha 2----6 sialylated counterpart are expressed in an oncodevelopmental manner. The short- and the long-chain Lex antigens are significantly enhanced in colonic carcinoma. The glycoproteins with NeuAc alpha 2----6GalNAc residues appear in gastric and colonic carcinoma as well as intestinalized gastric mucosa and transitional mucosa. Thus, some of these antigens were distinctively expressed in certain epithelial cells lining the normal gastrointestinal tract depending on maturation and patients' secretor status, and some were oncodevelopmental or carcinoma-associated antigens of the human gastrointestinal tract.

Antibodies, Monoclonal↗
PubMed1992

13C-nuclear magnetic resonance of glycosphingolipids.

Spectra of 125 MHz 13C-nuclear magnetic resonance (NMR) of glycosphingolipids, GlcCer, GalCer, sulfatide, LacCer, and nLc4Cer have been studied, and the following results were obtained. (i) Signals of ring carbons of each sugar component are distributed in a wide field (50-110 ppm) and clearly separated. (ii) Chemical shifts of anomeric carbon (C1) and methylene carbon (C6) of sugars are far from those of other methine carbons of sugars and characteristic of sugar components, which makes it possible to identify each sugar component and its molar raito. (iii) The downfield shifts (about 6-9 ppm) of alpha-carbon signals involved in the glycosidic linkages and upfield shifts (about 1.5-2 ppm) of the neighboring beta-carbons, which are known as glycosylation shifts, could be observed. (iv) Characteristic shifts of aglycon signals caused by the presence of an OH group at the alpha-position of fatty acid were assigned. These observations are useful for the characterization of glycosphingolipid structures.

Carbohydrate Conformation↗
PubMed1992

Studies on differentiation-inducing activities of triterpenes.

Differentiation-inducing activity of over 180 extracts of crude drugs and plants was tested using mouse myeloid leukemia cell line (M1). The methanol extracts of clove (Syzygium aromaticum Merrill et Perry, Myrtaceae) showed remarkable induction of differentiation of M1 cells into macrophage-like cells. From the extract, oleanolic acid (1) and crategolic acid (2) were isolated as the active components. We also tested other triterpenes, such as oleananes, ursanes and dammaranes, to investigate the structure-activity relationship. Some triterpene aglycones showed differentiation-inducing activity, but triterpene glycosides showed little activity. Furthermore, the differentiation-inducing activity of these triterpene compounds was tested against human acute promyelocytic leukemia cell line (HL-60).

Animals↗
PubMed1992

[Annual changes of bacteria isolated from urinary tract infections and their susceptibility to new quinolone agents].

Statistical analyses were conducted on bacterial strains isolated from the urine of patients with urinary tract infections (UTI) in the Department of Urology at Aichi Medical University from January 1988 through December 1991. The drug sensitivity of the bacterial strains isolated from patients with complicated UTI between 1988 and 1991 was analyzed and compared. Among the outpatients with uncomplicated UTI, a total of 352 strains were isolated. E. coli was isolated the most frequently (90.1%). Among the outpatients with complicated UTI, a total of 829 strains were isolated. Enterococcus sp. was isolated the most frequently (21.2%). P. aeruginosa and S. aureus showed a tendency to increase. Among the inpatients with complicated UTI, a total of 671 strains were isolated. Enterococcus sp. was isolated the most frequently (22.5%). P. aeruginosa and S. aureus showed a tendency to increase, while E. coli and Enterobacter sp. showed a tendency to decrease. E. coli was highly sensitive to all drugs except ampicillin (ABPC). Proteus sp. and Klebsiella sp. were highly sensitive to norfloxacin (NFLX). P. aeruginosa was highly sensitive to gentamicin (GM). The frequency of NFLX-sensitive P. aeruginosa significantly dropped from 84.6% to 40.9% among the outpatients (P < 0.01), and from 75.0% to 44.4% among inpatients (P < 0.05). S. aureus was highly sensitive only to minocycline (MINO). The frequency of NFLX-sensitive S. aureus significantly dropped from 66.6% to 23.3% among inpatients (P < 0.05). Enterococcus sp. was highly sensitive to ABPC and MINO. Of the new quinolones, tosufloxacin (TFLX) had the strongest antimicrobial activity followed by (ciprofloxacin) CPFX on all the bacterial strains tested.

Bacteria↗
PubMed1991

Physical dependence liability of dynorphin A analogs in rodents.

To assess the physical dependence liability of dynorphin A analogs, mice were given repeated injections of various dynorphin A analogs twice daily for 5 days, and rats were given repeated administration of [N-methyl-Tyr1,N-methyl-Arg7,D-Leu8]dynorphin-A-(1-8) ethylamide (E-2078) twice daily for up to 7 weeks. Mice that had received repeated [D-Cys2,Cys5,N-methyl-Arg7,D-Leu8]dynorphin-A-(1-9) amide displayed jumping behavior after subcutaneous injection of naloxone, an opioid receptor antagonist. In contrast, the animals that had received repeated E-2078 or [N-methyl-Tyr1,Phe4(p-NO2),N-methyl-Arg7,D-Leu8]dynorphin-A-(1-8) ethylamide displayed very few jumps after naloxone administration. Rats that had received repeated E-2078 administration did not display withdrawal signs, such as weight loss, after either abrupt withdrawal or naloxone administration. These results indicate that E-2078 and [N-methyl-Tyr1,Phe4(p-NO2),N-methyl-Arg7,D-Leu8]dynorphin-A-(1-8) ethylamide may have little dependence liability and that [D-Cys2,Cys5,N-methyl-Arg7,D-Leu8]dynorphin-A-(1-9) amide can cause physical dependence.

Analgesics↗
PubMed1991

Conformational structure of a monoclonal anti-idiotypic antibody to the monoclonal anti-adenocarcinoma-associated carbohydrate antibody YH206.

The mAb AI206 (IgG1) is an anti-Id antibody of mAb YH206 (IgM) to adenocarcinoma-associated carbohydrate Ag and inhibits the reaction of mAb YH206 to YH206 Ag at low concentrations. By Western blot analysis, mAb AI206 only reacted with unreduced mAb YH206, whereas it did not react with reduced mAb YH206. Furthermore, mAb AI206 reacted with IgM subunit (180 kDa), F(ab')2 (110 kDa), and F(ab) (50 kDa) of pepsin-treated unreduced mAb YH206. Thus, mAb AI206 recognized the structure of F(ab) of mAb YH206. The mAb YH206 reacted with unreduced mAb AI206, F(ab')2 (110 kDa), and F(ab) (50 kDa) of pepsin-treated unreduced mAb AI206. It is presumed that mAb YH206 and mAb AI206 recognize each other in an unreduced condition but not a reduced condition. The recognition of such a conformational Id on F(ab) is important. Because mAb YH206 recognized the carbohydrate on YH206 Ag as well as the peptide on mAb AI206, the conformation on F(ab) of mAb AI206 may mimic the carbohydrate structure on YH206 Ag. In fact, YH206 antibody activity was induced in syngeneic mouse serum immunized with mAb AI206. These observations suggest that the internal image of YH206 carbohydrate Ag is preserved within the conformational Id on F(ab) of mAb AI206.

Adenocarcinoma↗
PubMed1991

Had-1, a uridine 5'-diphosphogalactose transport-defective mutant of mouse mammary tumor cell FM3A: composition of glycolipids, cell growth inhibition by lactosylceramide, and loss of tumorigenicity.

Glycolipid compositions of mouse mammary tumor cell FM3A and its Newcastle disease virus-resistant mutant cell, Had-1, which was also characterized as a defective mutant of UDP-galactose transport to Golgi apparatus, have been studied. The major neutral glycolipid in FM3A was Gal beta 1-4Glc beta 1-1Cer (LacCer) (95%) and the rest was Glc beta 1-1Cer. The concentration of neutral glycolipids in Had-1 was only about one-fifth of that in FM3A. GlcB1-1Cer in Had-1 accounted for 79% of neutral glycolipids and the rest was LacCer, the content of which was decreased to 4% of that in FM3A. Ganglioside patterns of the two cell lines were similar, although gangliosides with N-glycolylneuraminic acid were increased in Had-1 cells compared with that in FM3A cells. The presence of NeuAc alpha 2-3-Gal beta 1-4GlcNAc beta 1-3Gal beta 1-4Glc beta 1-1Cer, NeuAc alpha 2-3Gal beta 1-4GlcNAc beta 1-3Gal beta 1-4GlcNAc beta 1-3Gal beta 1-4Glc beta 1-2Cer, GM3, and GD3 was demonstrated by thin-layer chromatography immunostaining. 125I-Labeled Newcastle disease virus bound only poorly to gangliosides extracted from either FM3A or Had-1 cells on a high performance thin-layer chromatography plate. The effects of glycolipids on the growth of the two cell lines were also studied. Had-1 cells were more sensitive to glycolipids added exogenously than FM3A cells. Addition of GM3 had a stimulative effect on cell growth of Had-1. LacCer, Gal beta 1-3GalNAc beta 1-4Gal beta 1-4Glc beta 4-1Cer, and Glc beta 1-1Cer inhibited the growth of Had-1 cells. LacCer was the most potent inhibitor. LacCer immobilized on the culture plate also inhibited the growth of Had-1 cells. The inhibitory effect was recovered completely overcome by transferring the cells to LacCer-free medium. Had-1 cells were not tumorigenic in C3H/He mice, and furthermore the tumorigenic activity of FM3A cells was suppressed by the prior administration of Had-1 cells.

Animals↗
PubMed1991

Prevention of cyclophosphamide-induced and spontaneous diabetes in NOD/Shi/Kbe mice by anti-MHC class I Kd monoclonal antibody.

The immune mechanisms directly responsible for beta-cell destruction in insulin-dependent diabetes are undefined. We studied the role of MHC class I-restricted T lymphocytes in the development of diabetes in cyclophosphamide (CY)-treated male and untreated female NOD mice (H-2Kd,Db). After administration of CY to 10-wk-old male NOD/Shi/Kbe mice, 37 of 64 (58%) phosphate-buffered saline-injected control mice and 13 of 22 (59%) anti-Kb and 12 of 27 (44%) anti-Db monoclonal antibody (MoAb)-injected mice became diabetic by 14 wk of age, whereas only 3 of 38 (8%) anti-Kd and 2 of 13 (15%) anti-Lyt-2 MoAb-injected mice did. In untreated female NOD/Shi/Kbe mice, 30 of 46 (65%) mice developed spontaneous diabetes by 30 wk of age, whereas none of 9 anti-Kd MoAb-injected mice became diabetic. Immunohistochemical studies showed that islet-infiltrating cells in CY-treated control mice were composed mainly of both L3T4+ and Lyt-2+ T lymphocytes, whereas many L3T4+ and very few Lyt-2+ lymphocytes infiltrated within the islets in anti-Kd MoAb-injected mice. Administration of anti-Lyt-2 MoAb induced the absence of Lyt-2+ T lymphocytes in the islet and spleen. However, anti-Kd MoAb did not change the number of spleen cells or the T-lymphocyte subset and response to concanavalin A. These results suggest that MHC class I Kd-restricted Lyt-2+ T lymphocytes play an important role as direct effector cells in destruction of beta-cells in NOD/Shi/Kbe mice.

Animals↗
PubMed1991

[Treatment of malignant gliomas by selective intraarterial infusion chemotherapy with high-dose ACNU and autologous bone marrow transplantation--preliminary report].

Six patients with malignant gliomas were treated by selective intracarotid infusion of ACNU at 15 mg/kg (about 600 mg per m2) or 10 mg/kg with or without radiotherapy and rescue of autologous bone marrow transplantation after surgery. These high doses of ACNU were well tolerated if bone marrow rescue was performed and granulocyte colony stimulating factor was used. With the development of microcatheters for use in selective intraarterial infusion, it has become possible to cannulate the major artery and infuse drugs at high dose into the artery feeding the tumor. The complication of ocular toxicity can be avoided by using the Tracker-18 or Balt (Magic) angiographic catheter. On the other hand, drug dosage and infusion rate must be chosen carefully, because of the increased likelihood of local arteritis and local necrosis caused by high dosage of ACNU. In the present study, local arteritis or cerebral infarction in the area of the middle cerebral artery was considered to have been prevented by extending the infusion time to 80 minutes. When combined with radiotherapy, 10 mg/kg of ACNU and 80 min. of infusion time were found to be optimal in relation to brain tolerance.

Adolescent↗
PubMed1991

[Monoclonal antibody MIA15-5, which inhibits cell motility and metastatic potential, has a great effect on the prognosis of the post-surgical patients with lung cancer].

The functional monoclonal antibody, selected based on the inhibition of cell motility, was found to be directed to specific carbohydrate structure Fuc alpha 1----2 Gal beta 1----R. This monoclonal antibody, MIA15-5 was established after immunization of mice with adenocarcinoma line of the lung PC7, and selected based on inhibition of U937, HEL, and MAC10 cell migration due to the transwell assay. MIA15-5 reacted with 30-40% of high metastatic variant BL6 of mouse melanoma B16 line and metastatic deposition to lung after injection of BL6 cells was strongly inhibited if MIA15-5 was injected within 3 hours, but was not inhibited by injection of other anti-H antibodies under the same conditions. Injection of MIA15-5 had much less inhibitory effect if administered 1 day after BL-6 injection, and no effect at 3 days. In immunohistochemical staining of 149 formalin fixed specimens of patients with lung cancer, especially adenocarcinoma has the highly frequency of MIA15-5 (65.4%, 49 of 75 cases) and the five year survival rate of the patients with negative staining of MIA15-5 was 58.6% and much better than one with positive staining, 20.9%.

Adenocarcinoma↗
PubMed1991

[Distribution and acute toxicity of a new morpholinoanthracycline, MX2, in normal rat brain after intra-arterial injection].

Intra-arterial infusion chemotherapy has been applied for the treatment of malignant brain tumors to increase the distribution of the drug into the tumor. MX2, a new morpholinoanthracycline, is a lipophilic compound, and has a strong antineoplastic effect against human and rat glioma cells. In this report, the acute toxicity and distribution of MX2 after intracarotid injection were studied using female Wistar rats weighing 150 g. To test the acute toxicity, various doses ranging 1.5 to 6 mg/kg was administered. All rats died within 4 days when received more than 3 mg/kg of intra-arterial or intravenous MX2. No rats died if the dose was reduced to less than 2 mg/kg. For the purpose to examine distribution in the brain, rats which received 2 mg/kg of intra-carotid MX2 were killed 5 to 120 min. after injection. The level of MX2 in the ipsilateral brain tissue reached to the maximum 5 min. after injection, and then rapidly decreased. The maximum concentration of MX2 in the ipsilateral brain was 25-fold higher than that in the contralateral brain, and 20-fold higher than that after intravenous injection of the same dose. The AUC (area under the curve) in the ipsilateral brain after intra-carotid injection was 8.0-fold higher than that in the contralateral brain, and 7.3-fold higher than that after intravenous injection of the same dose. These results indicate that intra-carotid administration can increase the distribution of MX2 in the normal brain.

Animals↗
PubMed1990

Accumulation of gangliosides with N-acetylneuraminosyl(alpha 2-6)lactosamine structure in primary human hepatoma.

Gangliosides of hepatomas have been analyzed by using a monoclonal antibody directed to N-acetylneuraminosyl(alpha 2-6)lactoneotetraosylceramide (sialyl(alpha 2-6)paragloboside), which was prepared by injecting the monosialoganglioside fraction of human meconium into BALB/c mice. The monoclonal antibody, named MSG-15, was found to bind sialyl(alpha 2-6)paragloboside, but it failed to react with other gangliosides, including N-acetylneuraminosyl(alpha 2-3)lactoneotetraosylceramide (sialyl (alpha 2-3)paragloboside) and "Ii"-type gangliosides. MSG-15 was found to recognize NeuAc alpha 2-6Gal beta structure of the ganglioside. Gangliosides obtained from human hepatomas were analyzed by immunostaining on high-performance thin-layer chromatography plates using the monoclonal antibody MSG-15. All primary hepatoma samples used in this study (nine samples) were found to contain sialyl(alpha 2-6)paragloboside, which accounted for 13-31% of the monosialoganglioside fractions in the hepatomas. Furthermore, MSG-15 recognized several monosialogangliosides in addition to sialyl(alpha 2-6)paragloboside. These gangliosides apparently also contain a terminal NeuAc alpha 2-6Gal beta structure. Other ganglioside fractions obtained from hepatoma and meconium were immunostained on thin layer chromatography plates with MSG-15. Additionally, another monoclonal antibody (H-11), which recognizes terminal lactosamine structure, was used to immunostain these fractions after sialidase treatment. Bands stained with both monoclonal antibodies showed similar mobilities to each other in the di- and trisialoganglioside fractions as well as monosialoganglioside fraction. In control liver, GM3 ganglioside accounted for 92% of monosialoganglioside fraction, and sialyl(alpha 2-6)paragloboside accounted for less than 1% of the fraction. Immunohistochemical study by using MSG-15 in tissue sections from hepatocellular carcinoma and normal liver tissues demonstrated that only hepatocellular carcinoma cells gave a positive reaction. These results suggest that the biosynthetic pathway of gangliosides containing NeuAc alpha 2-6Gal beta 1-4GlcNAc beta structure is activated in hepatoma cells.

Animals↗