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Biomedical subjects

I Yamashina

Publications and source records attributed to I Yamashina.

At least 37 records · Page 2Linked to original sources
PubMed1995

Radioimmunoimaging of colon cancer xenografts with anti-Tn monoclonal antibody.

Tn antigen is a glycosylated tumor associated antigen and a murine monoclonal antibody, MLS128, has been identified to react with it. The potential of MLS128 for the radioimmunoimaging of colorectal cancer was studied. MLS128 was labeled with radioiodine by the chloramine-T method or indium-111 (111In) by using isothiocyanatobenzyl EDTA, and was injected into nude mice bearing human colon cancer xenografts. Radiolabeled MLS128 showed a high and specific localization in xenografted tumor. At 48 h after injection, the %ID/g of 125I-labeled MLS128 in the tumor was 34.69, whereas that of isotype matched control antibody, FLOPC21, was 5.58 and the tumor-to-nontumor radioactivity ratios of 125I-labeled MLS128 reached to 4.56, 17.84 and 23.62 for the blood, liver and bone, respectively. 111In-labeled MLS128 showed similar results. High accumulation of MLS128 in xenografted tumors suggested that the monoclonal antibody MLS128 is promising for radioimmunoimaging of colorectal cancer.

Animals↗
PubMed1995

Improved targeting of radiolabeled streptavidin in tumors pretargeted with biotinylated monoclonal antibodies through an avidin chase.

UNLABELLED: Radiolabeled streptavidin can be accumulated in tumors pretargeted with biotinylated anti-tumor antibodies. However, circulating biotinylated antibody and endogenous biotin may interfere with the tumor targeting of streptavidin. To reduce biotinylated antibody concentration in the blood, we injected avidin before streptavidin administration. The effects of avidin administration on the biodistribution and tumor targeting of radiolabeled streptavidin were examined. METHODS: Biotinylated anti-human colon cancer monoclonal antibody (MAb) MLS128 was injected intravenously into nude mice bearing human colon cancer xenografts for pretargeting. After intraperitoneal injection of avidin, radioiodinated streptavidin was administered and its biodistribution and tumor accumulation was investigated. RESULTS: Radioiodinated streptavidin specifically localized in the tumor pretargeted with biotinylated antibody. Avidin preadministration accelerated the tumor uptake and blood clearance of radioiodinated streptavidin. The tumor-to-blood radioactivity ratio at 6 and 24 hr after radiolabeled streptavidin injection were 1.23 +/- 0.29 and 3.04 +/- 0.86, respectively, in mice with avidin chase (mean +/- s.d., n = 7), and 0.82 +/- 0.17 and 2.29 +/- 0.29, respectively, in those without chase (mean +/- s.d., n = 7). CONCLUSION: Localization of radiolabeled streptavidin in tumors pretargeted with biotinylated MAb could be improved by avidin chase. This approach may be useful for tumor radioimmunoimaging and radioimmunotherapy.

Animals↗
PubMed1994

Tn antigen is expressed on leukosialin from T-lymphoid cells.

Various T-lymphoid cells were labeled with [3H] glucosamine and then cell lysates were prepared from them. The Tn antigen was immunoprecipitated and analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis followed by fluorography. The Tn antigen was found to be expressed on leukosialin, a major glycoprotein of T-lymphoid cells. The carbohydrate moieties of leukosialin were isolated from Jurkat and Molt 4 cells by alkaline borohydride treatment. The leukosialin in both cases predominantly contained single N-acetylgalactosamine residues, consistent with expression of the Tn antigen. Tryptic glycopeptides containing antigenic sites were isolated using an MLS 128 immunoaffinity column and purified by gel filtration and reverse phase column chromatographies. Sequence analyses revealed that all the glycopeptides obtained contained three consecutive residues of N-acetylgalactosamine-Ser/Thr, supporting the idea that the epitopic structure is a cluster of N-acetylgalactosamine-Ser/Thr.

Antigens, CD↗
PubMed1994

Reduced bone marrow uptake of indium-111 labelled monoclonal antibody after radiotherapy.

Uptake of indium-111 in bone marrow is seen in patients who have received 111In-labelled antibody. We report a case in which 111In uptake was not seen in the area of previous irradiation whereas fairly high uptake was noted in other bone marrow areas. 111In-labelled monoclonal antibody, which reacts with mucin, was injected into a patient with cancer of the sigmoid colon who had received radiotherapy for uterine cervical cancer 5 years previously. Marked accumulation of the antibody was observed in the tumour. Uptake of 111In in bone marrow was also seen except in the previously irradiated pelvic region. This phenomenon supports the idea that bone marrow uptake of 111In is the result of transchelation of 111In from antibody to transferrin.

Aged↗
PubMed1994

Coexpression of cancer-associated carbohydrate antigens, Tn and sialyl Tn.

The expression of cancer-associated antigens, Tn and sialyl Tn, was examined using monoclonal antibodies, MLS 128 and MLS 102, recognizing these two antigens, respectively. A cell lysate from a human carcinoma cell line, LS 180 cells, was analysed by Western blotting using these two antibodies. Three glycoprotein bands were discernible with each antibody, of which two, corresponding to 250 and 210 kDa, were reactive with both the antibodies. LS 180 cells were metabolically labelled with 3H-glucosamine and then the lysate from these cells was applied to two immunoaffinity columns. Sixty-five per cent of the Tn antigenic glycoproteins, based on radioactivity, bound to the MLS 102 affinity column. On the other hand, 45% of the sialyl Tn antigenic glycoproteins bound to the MLS 128 affinity column. These results indicate that some Tn and sialyl Tn antigens were expressed on the same polypeptide chains. The presence of non-sialylated GalNAc residues on the polypeptide chain with many Sia-GalNAc residues appears to be due to the incapability of three consecutive moieties of GalNAc-Ser/Thr to accept sialic acid.

Antigens, Tumor-Associated, Carbohydrate↗
PubMed1994

Expression of sialosyl-Tn antigen (monoclonal antibody MLS102 reactive) in normal tissues and malignant tumors of the digestive tract.

Oncogenic transformation is often associated with changes in the glycosylation state of malignant cells. We investigated the immunohistochemical localization of sialosyl-Tn antigen [O-linked NeuAc(alpha 2-->6)GAINAc] using a novel monoclonal antibody MLS102 in normal and malignant digestive-tract tissues. In normal tissues, weak MLS102 immunoreactivity was observed in the epithelium of the esophagus, stomach and colon. However, MLS102 immunoreactivity was strong in the goblet cells of the duodenum, but not in the Brunner glands. In carcinomas of the esophagus, stomach, colon, pancreas and biliary tract, positive staining was detected with a high frequency (80%-100%). In mucinous carcinomas and signet-ring cell carcinomas, malignant cells themselves and the mucins they secreted were strongly positive for sialosyl-Tn antigen. There was no significant correlation between the frequency of expression of sialosyl-Tn antigen and the degree of differentiation (grade). However, in the case of well-differentiated adenocarcinomas, sialosyl-Tn antigen was found mainly in the supranuclear areas (Golgi area), on the apical surface and in the adjacent cytoplasm. In poorly differentiated adenocarcinomas, the antigen was often detected in the whole plasma membrane and cytoplasm. Therefore, monoclonal antibody MLS102 may be useful in further elucidating the characteristics of digestive-tract cancers, and possibly in their treatment.

Antibodies, Monoclonal↗
PubMed1993

Novel gangliosides containing the sialyl-Le(a) structure from a human rectal adenocarcinoma.

Oligosaccharides were released from the gangliosides of a human rectal adenocarcinoma with endoglycoceramidase (Rhodococcus sp. G-74-2) and then purified by affinity chromatography on a column of an immobilized monoclonal antibody, MSW 113. Structural studies, involving 600-MHz 1H NMR spectrometry, indicated the structures of these compounds to be as follows. [formula: see text] Three of these oligosaccharides, 2, 3, and 4, are novel as to ganglioside sugar chains and contain both lacto series types 1 and 2 chains. Oligosaccharides 3 and 4 are unique in that they contain the sialyl-Le(a)-X structure in linear and branched structures. Gangliosides with the oligosaccharide structures presented above might be new potential tumor markers.

Adenocarcinoma↗
PubMed1993

Epitopic structure of Tn glycophorin A for an anti-Tn antibody (MLS 128).

Glycophorin A was digested with glycoprotease (Pasteurella haemolytica) and the digest was fractionated by a combination of high-pressure column chromatographies to produce the glycopeptides GPA-1 to GPA-6. Sequence analysis of the glycopeptides revealed that two serine residues (Ser-14 and Ser-15) are not glycosylated, Thr-17 and Ser-19 being glycosylated instead, in disagreement with the accepted structure. The glycopeptides thus obtained were treated with sialidase and beta-galactosidase. The Tn antigenicity, as assayed by the binding to a monoclonal anti-Tn antibody (MLS 128), was found exclusively in the glycopeptides including three (cluster I) or four (cluster II) consecutive residues of GalNAc-Ser/Thr, whereas the glycopeptide (GPA-2) containing two nonconsecutive GalNAc-Ser/Thr residues had practically no Tn antigenicity. The immunoreactivities of GPA-1 and GPA-3, containing both clusters I and II, and GPA-4, containing cluster II, were 63% (calcd. 67%), 81% (calcd. 86%), and 50% (calcd. 50%), respectively, of the immunoreactivity of GPA-5 or GPA-6, containing cluster I (the average being taken as the basis), based on the reactivity per GalNAc residue. These results indicate that clusters I and II react with the antibody to the same extent. The structure consisting of three consecutive glycosylated Ser/Thr residues may be essential for Tn antigenicity in the light of previous results for ovine submaxillary mucin.

Amino Acid Sequence↗
PubMed1993

Novel oligosaccharides with the sialyl-Le(a) structure in human milk.

Two novel oligosaccharides with the sialyl-Le(a) structure were isolated from human milk using a monoclonal antibody, MSW 113. These oligosaccharides were purified by affinity chromatography on a column of the immobilized monoclonal antibody and by high-performance liquid chromatography, and structurally characterized by a combination of 600-MHz 1H NMR spectroscopy and fast atom bombardment mass spectrometry. The structural studies indicated the structures of these oligosaccharides to be: [formula: see text]

Antibodies, Monoclonal↗
PubMed1992

Cancer-associated glycoproteins defined by a monoclonal antibody, MLS 128, recognizing the Tn antigen.

A murine monoclonal antibody, MLS 128, recognizing the Tn antigen, was established and used for characterization of glycoproteins expressing the Tn antigen. The Tn antigen was expressed on three polypeptide chains with molecular weights of 250k, 210k and 150k daltons. LS 180 cells were labeled with 3H-glucosamine or 35S-sulfate metabolically, and then the immunoprecipitate derived from the cell lysate was subjected to SDS-PAGE followed by fluorography. It was revealed that these Tn antigen glycoproteins were produced through the processing of a high molecular weight precursor. The carbohydrate moieties of the Tn antigen glycoproteins labeled with 3H-glucosamine were released with alkaline-borohydride, and the released sugars were examined by gel filtration and paper chromatography. The carbohydrates predominantly consisted of GalNAc and sialyl GalNAc (greater than 90%), with a nearly equal distribution.

Antibodies, Monoclonal↗
PubMed1992

Novel structure of the N-acetylgalactosamine containing N-glycosidic carbohydrate chain of batroxobin, a thrombin-like snake venom enzyme.

The structure of the Asn-linked carbohydrate chain of batroxobin, a thrombin-like enzyme from Bothrops atrox moojeni snake venom, has been determined. The sugar chain was isolated from batroxobin by hydrazinolysis followed by pyridylamination (PA). The PA-oligosaccharide chain was purified by HPLC on an anion exchange or reverse phase columns, and its structure was examined by sequential exoglycosidase digestion, 600 MHZ 1H NMR spectroscopy and methylation analysis. The results indicate that the oligosaccharide chain has the following structure involving a novel linkage, NeuAc alpha 2----3GalNAc.

Acetylgalactosamine↗
PubMed1991

Structural studies on sulfated oligosaccharides derived from the carbohydrate-protein linkage region of chondroitin sulfate proteoglycans of whale cartilage.

From the carbohydrate-protein linkage region of whale cartilage proteoglycans, which bear predominantly chondroitin 4-sulfate, one nonsulfated, two monosulfated and one disulfated hexasaccharide alditols were isolated after exhaustive digestions with Actinase E and chondroitinase ABC, and subsequent beta-elimination. Their structures were analyzed by chondroitinase ACII digestion in conjunction with HPLC and by 500-MHz 1H-NMR spectroscopy. The nonsulfated compound (A) had the following conventional structure: delta GlcA(beta 1-3)-GalNAc(beta 1-4)GlcA(beta 1-3)Gal(beta 1-4)Xylol, where GlcA, delta GlcA and GalNAc are glucuronic acid; 4,5-unsaturated glucuronic acid and 2-deoxy-2-N-acetylamino-D-galactose, respectively. The other compounds were sulfated derivatives of compound A. Two monosulfated compounds (B and C) had an ester sulfate on C4 or C6 of the GalNAc residue, respectively and the disulfated compound (D) had two ester sulfate groups, namely, one on C4 of the GalNAc and the other on C4 of the Gal residue substituted by GlcA. The molar ratio of A/B/C/D was 0.21:0.16:0.36:0.27. The compound containing Gal-4-O-sulfate was previously isolated by us in the form of a sulfated glycoserine [delta GlcA(beta 1-3)GalNAc(4-O- sulfate)(beta 1-4)GlcA(beta 1-3)Gal(4-O-sulfate)(beta 1-3)-Gal(beta 1- 4)Xyl beta 1-O-Ser] from the carbohydrate-protein linkage region of rat chondrosarcoma chondroitin-4-sulfate proteoglycans [Sugahara K., Yamashina, I., DeWaard, P., Van Halbeek, H. & Vliegenthart, J.F.G. (1988) J. Biol. Chem. 263, 10,168-10,174]. The discovery of this structure in the carbohydrate-protein linkage region of chondroitin 4-sulfate proteoglycans from nontumorous cartilage indicates that it is not a tumor-associated product but rather a physiological biosynthetic product since it represents a significant proportion. The biological significance of this structure is discussed in relation to glycosaminoglycan biosynthesis.

Animals↗
PubMed1991

Expression of the Tn antigen on T-lymphoid cell line Jurkat.

Expression of the Tn antigen on a T-lymphoid cell line, Jurkat, was investigated using an anti-Tn monoclonal antibody, MLS 128. Immunoprecipitation or immunoaffinity chromatography of a lysate of Jurkat cells led to the isolation of a 120 kDa glycoprotein carrying the Tn antigen. This glycoprotein and leukosialin (CD43) were indistinguishable on SDS-PAGE and as to immunoreactivity with MLS 128. Leukosialin from an erythroid cell line, K562, exhibited no reactivity with MLS 128 despite that this leukosialin has several GalNAc alpha-Ser(Thr) structures. Pulse-chase experiments with the Jurkat leukosialin showed that newly synthesized leukosialin acquired the antigenecity after a lag of about 30 min, whereas incorporation of GalNAc into the leukosialin occurred earlier. These results indicate that the Tn antigen is expressed on leukosialin and that its epitopic structure is more complex than GalNAc alpha-Ser(Thr).

Amino Acid Sequence↗
PubMed1991

Characterization of mucin-type oligosaccharides with the sialyl-Le(a) structure from human colorectal adenocarcinoma cells.

Oligosaccharides with the sialyl-Le(a) structure have been isolated on an affinity column of a monoclonal antibody, MSW 113, from mucin-type glycoproteins derived from the surfaces of SW 1116 and LS 180 cells, and their secretions. The oligosaccharides were polydisperse with respect to molecular size, the oligosaccharides derived from glycoproteins in culture media being larger than those in cell lysates, as assessed by gel filtration. Some of the oligosaccharides were susceptible to degradation by endo-beta-galactosidase (E. freundii), as judged from the change in the gel filtration pattern. These results indicate that oligosaccharides with the sialyl-Le(a) structure derived from mucin-type glycoproteins produced by human colonic cancer cells are extremely large in size and complex in structure, and that some of them contain the poly-N-acetyllactosamine structure.

Adenocarcinoma↗
PubMed1991

Elucidation of an essential structure recognized by an anti-GalNAc alpha-Ser(Thr) monoclonal antibody (MLS 128).

To determine the epitopic structure for an anti-GalNAc alpha-Ser(Thr) (anti-Tn) monoclonal antibody, MLS 128, asialo-ovine submaxillary mucin was digested with various proteases, and the digests were fractionated by immunoaffinity column chromatography and high performance liquid chromatography. From the tryptic digest, a glycopeptide, GP-I, and five other glycopeptides, GP-1-5, were obtained as bound and unbound fractions, respectively, of the immunoaffinity column. By solid phase radioimmunoassaying, it was found that GP-I was strongly immunoreactive, whereas GP-1-5 were poorly immunoreactive. On treatment with V8 protease, GP-I was converted to two glycopeptides, one with poor reactivity and the other with intermediate reactivity. From the thermolysin digest, the smallest fragment, GP-II, was isolated, which was as strongly immunoreactive as GP-I. GP-II corresponded to a part of GP-I, its sequence being Leu-Ser*-Glu-Ser*-Thr*-Thr*-Gln-Leu-Pro-Gly, where asterisks denote amino acids to which an alpha-GalNAc residue is attached. Other anti-Tn monoclonal antibodies, NCC-LU-35 and CA 3239, showed essentially the same reactivity to these glycopeptides as MLS 128 did. The glycopeptides (GP-1-5), which exhibited poor immunoreactivity, contained various GalNAc-containing structures, such as GalNAc-Ser, GalNAc-Thr, GalNAc-Ser-(GalNAc)-Ser, and GalNAc-Thr-(GalNAc)-Thr. These results indicate that a glycopeptide including a cluster structure, Ser*-Thr*-Thr*, is an essential part of the epitope recognized by anti-Tn antibodies.

Amino Acid Sequence↗