Biomedical subjects

H J Gabius

Publications and source records attributed to H J Gabius.

At least 343 records · Page 19Linked to original sources

PubMedDate not supplied

Macrophage-like-cell-induced growth regulation of lymphoma cells.

Since hematopoietic stromal cells play a major role in regulating the growth and differentiation of hematopoietic cells, we have studied the effects of stromal cells on the in vitro growth of highly malignant murine RAW117-H10 lymphoma cells. These cells, when grown on a preformed layer of syngeneic Balb/c macrophage/monocyte cell line, J774A.1, stop proliferating 48 h after coculture. This stromal-cell-mediated growth regulation appears to require cell-to-cell contact between stromal cells and RAW117-H10 cells, since the J774A.1 cell supernatant did not significantly inhibit the in vitro growth of RAW117-H10 cells. Because one of the cytokines produced by the macrophages is tumor necrosis factor (TNF)-alpha, which is known to inhibit certain tumor cells, we also studied the effects of various concentrations of TNF-alpha on the in vitro growth of RAW117-H10 lymphoma cells. TNF-alpha did not significantly affect the growth of these cells in vitro. However, TNF-alpha induced significant morphologic changes in these cells similar to those seen in plasma cytoid differentiation. Thus, our results indicate that the macrophage-like stromal cells regulate the in vitro growth of malignant lymphoma cells, and that direct cell surface contact between stromal and lymphoma cells is necessary for the growth regulation, and the growth inhibition is not due to TNF-alpha secreted by the macrophages. TNF-alpha is associated with differentiation of these lymphoma cells.

Animals↗

PubMedDate not supplied

Will neoadjuvant chemotherapy affect the capacity of head and neck squamous cell carcinoma to bind neoglycoproteins?

Evidence is growing that the carbohydrate portion of glycoconjugates is not merely an inert structural addition to the protein or lipid background, but is involved in normal and altered physiological processes. Conjugation of the potentially bioactive carbohydrate ligand to an inert labeled carrier generates the tools to histochemically monitor the presence of sugar receptors like lectins in tissue sections. In head and neck squamous cell carcinoma endogenous lectins have been systematically characterized by a selected panel of conjugates of such synthetic probes. In this investigation we provide evidence that the antineoplastic agents carboplatin and 5-fluorouracil influence the expression of carbohydrate-binding receptors. In cases with a statistically significant alteration, an increasing loss of binding capacity from treatment cycle to cycle was observed in cytoplasmic areas. This means that the extent of binding of beta-N-acetyl-galactosamine, cellobiose, galactose, and sialic acid was affected. The pattern of diminished binding capacity in nuclear structures encompassed beta-N-acetyl-galactosamine, beta-N-acetyl-glucosamine, sialic acid as carbohydrate part of the neoglycoprotein. Thus, exposure to certain chemotherapeutic agents clearly influences the capacity of tumor cells to mediate protein-carbohydrate interactions. Concomitant with the elucidation of the functions of such an interplay the significance of this down-regulation will be apparent.

Binding Sites↗

PubMedDate not supplied

Are differences in the expression of carbohydrate-binding sites (endogenous lectins) responsible for recurrences of benign tumours of the parotid gland?

The expression of endogenous lectins in pleomorphic adenomas and papillary cystadenoma lymphomatosum (Warthin tumour) as well as in the tissue of the normal parotid gland was investigated with the aim to determine the capacity of the different cells to specifically bind carbohydrate ligand structures. The loss of sugar-binding sites of pleomorphic adenomas - lactose (diazonium derivative; diaz.), beta-N-acetylgalactosamine (diaz.), sialic acid [(2,3-epoxypropane)-4-oxybutyric acid linked; epichl.], heparin, mannose-6-phosphate (diaz.), maltose (diaz.), xylose (diaz.), melibiose (diaz.), N-acetylgalactosamine (epichl.) - was detected in the investigated tumours, leading to the hypothesis that altered carbohydrate-protein interactions have been involved in the adhesion of lost pleomorphic adenoma cells after damaging the tumour capsule. The papillary cystadenoma lymphomatosum in its cytoplasmic areas expressed significantly fewer sugar-binding sites for alpha-N-acetylgalactosamine (diaz.) and melibiose (diaz.).

Acetylgalactosamine↗

PubMedDate not supplied

Aminoacyl-tRNA synthetases in liver, spleen and small intestine of aged leukemic and aged normal mice.

The specific activities of 17 aminoacyl-tRNA synthetases in liver, lung, heart, spleen, kidney and small intestine of old female normal and leukemic (reticulum-cell sarcoma, type A) mice have been monitored. No difference appears for lung, heart and kidney; small increases with varying particular changes for liver and marked increases in spleen and small intestine of the tumor bearing mice have been found, following a similar pattern. This finding suggests a coordinated adaptation to modulation of the requirements of protein synthesis imposed by histiocytic sarcoma.

Aging↗

PubMedDate not supplied

Sialic acid-binding proteins: characterization, biological function and application.

The last decade has witnessed steadily growing support for the notion that the carbohydrate portion of glycoconjugates is not merely an inert structural addition to the protein or lipid backbone. Considerable attention has been given to the chemical composition of glycosidic residues in such heteropolymers. Sialic acids are frequently occurring components of oligosaccharide side chains in glycoconjugates of most higher animals and a few microorganisms. They appear to play an important role as ligands in glycobiological interactions. Mediation of a proposed protein-carbohydrate recognition will necessarily involve a binding protein with the respective specificity. Such proteins thus are able to serve as receptors for certain types of carbohydrate moieties like sialic acids in vivo. Various members of this class of proteins have already proven their value as analytical tools in studying expression and localization of defined sialoglycoconjugates. These proteins attract much attention due to both their functions in situ and their potential as laboratory tools in glycoconjugate research in areas like biochemistry or histology. We present a survey of the purification, characterization and application of this class of proteins to illustrate the status of knowledge and the current directions of research in this field.

Animals↗

PubMedDate not supplied

Glycohistochemical monitoring of chemically induced sarcomas at different stages of tumorigenesis.

Malignant soft tissue tumors still represent a source of uncertainty and controversy concerning histogenetic origin and histological behavior. Considering this, chemically induced sarcomas furnish an attractive model for the elucidation of cellular alterations during tumorigenesis. This approach allows us to closely follow cyto- and histological changes within coherent stages of tumor development. The specimen under scrutiny comprised 35 rat tissue samples from day 10 up to day 200 after benzo[a]pyrene injection. Additionally, for comparison and validation two human malignant fibrous histiocytomas (MFH) were investigated. The essential biological significance of protein-carbohydrate interactions warranted the histochemical application of synthetic tools (neo-glycoproteins-NGP) and lectins in order to reveal phenotypical dynamics in this aspect throughout the process of tumor development. Namely, 6 plant lectins (carbohydrate-binding proteins with defined saccharide specificity), 7 custom-made synthetic NGP (as the corresponding ligands visualizing endogenous lectins) and additionally three antibodies were employed. Characteristic cell populations were histochemically demonstrated in four stages of tumor development: exudation (n = 5), mesenchymal proliferation (n = 7), atypical granulation tissue (n = 7) and sarcoma (n = 16). Changes of glycohistochemical binding patterns were in close phenotypic relation to cellular activity, differentiation, local distribution as well as malignant transformation and tumor progression. At present, the new glycobiological features of the malignant phenotype substantiate the assumption that not only glycosylation but also the receptor display is altered upon carcinogenesis. In conclusion, this chronological longitudinal study takes advantage of the combination of a coherent model of tumorigenesis with innovative histochemical tools whose ligands are supposed to act as mediators of cell-cell- and cell-matrix interactions. It clearly demonstrates the suitability of the glycohistochemical method for comparative approaches. The systematic analysis of glycohistochemical determinants will improve our understanding of the early tumor biological processes with potential implications for therapeutic interventions.

Animals↗

PubMedDate not supplied

Expression of endogenous lectins (galectins, receptors for ABH-epitopes) and the MIB-1 antigen in esophageal carcinomas and their syntactic structure analysis in relation to post-surgical tumor stage and lymph node involvement.

Squamous cell carcinomas of the esophagus, a disease with poor prognosis, are especially frequent in China and South Africa. To initiate the study of endogenous lectins in this tumor class we employed synthetic neoglycoconjugates and focused on galectins as markers. Histological sections of 43 cases of esophageal carcinomas were analyzed with labeled galectins-1 and -3 and their specific antibodies, neoglycoconjugates exposing chemically prepared histo-blood group A-, B- and H-trisaccharides and the antibody MIB-1 (Ki-67). Features of structural and numerical staining intensities determined quantitatively were correlated to clinical data sets of pTN stages, sex and age of patients. Low tumor stages (pT1/T2) were seen in 10/43 cases (23%) and 65% of the carcinomas surgically treated lacked notable lymph node involvement (pN0). The women were younger than the men (47 years versus 54 years). The proliferation activity of the tumor cells was high and amounted to 75% at average. The presence of galectin-1 and the structural entropy of distribution of staining with carrier-immobilized A-trisaccharide were associated with pN stages. These initial data indicate that distinct glycohistochemical features appear to have prognostic significance in this tumor class, adding to the emerging significance of this marker class in lung cancer.

ABO Blood-Group System↗

PubMedDate not supplied

Lectin (WGA)-dependent superoxide anion release by neutrophils as a prognostic factor in lung cancer.

This study was performed to explore whether lectin-induced generation of superoxide anions by neutrophils, lectin-induced degranulation of these cells and NO-synthase activity in pleural effusions can be used as prognostic factors of primary lung cancer patients. Among the activities tested, increased generation of superoxide by Triticum vulgaris agglutinin (WGA)-activated neutrophils showed prognostic relevance. Thus, this lectin-dependent reactivity of immune cells warrants further investigation in addition to the histochemical analysis.

Cell Degranulation↗

PubMedDate not supplied

The immunomodulatory beta-galactoside-specific lectin from mistletoe: partial sequence analysis, cell and tissue binding, and impact on intracellular biosignalling of monocytic leukemia cells.

Nanogram quantities of the beta-galactoside-specific lectin from mistletoe (ML-I) that is composed of two different types of subunits exhibit immunomodulatory potency and enhance cytokine secretion in vitro and in vivo. Partial sequence analysis of the carbohydrate-binding B chain revealed a ragged N-terminus and overall homologies to the B subunit of Ricin D and Ricin E. Two evolutionarily neutral substitutions were apparent in the otherwise identical N-terminal sequences of the two toxic chains within the lectin preparation. On the basis of the influence of chemical modification by group-specific reagents on ligand binding, the lectin was biotinylated with biotinyl-N-hydroxysuccinimide ester to allow monitoring of cell binding. Monocytic leukemia cells (THP-1) specifically bound the lectin with positive cooperativity at low lectin concentrations. Radiolabelled lectin could be found in several organs and in an experimental solid tumor in biodistribution in mice. Its presence in a notable amount in spleens is especially noteworthy with respect to the already reported immunomodulation. To determine intracellular responses that precede the lectin-dependent augmentation of cytokine secretion, phosphorylation of proteins and phospholipids as well as Ca(2+)-mobilization were assessed in THP-1 cells. Quantitative increases of [32P]-phosphate incorporation were determined for a 28 kDa protein and for phosphatidylinositol-4,5-biphosphate. Similarly, the fluorescence activity of the intracellular Ca(2+)-indicator fluo-3 is elevated by approximately 25% after lectin treatment. Apparently, cell binding of the lectin is followed by modulation of biosignalling processes.

Amino Acid Sequence↗

PubMedDate not supplied

Neoglycoprotein binding to normal urothelium and grade-dependent changes in bladder lesions.

Chemical conjugation of carbohydrate derivatives to a labelled carrier protein makes it possible to monitor the presence of specific sugar-dependent binding to routinely processed tissue sections. Different levels of cytoplasmic staining were observed in normal urothelium for the applied probes that expose a beta-D-galactoside, alpha- or beta-N-acetyl-D-galactosaminide, beta-N-acetyl-D-glucosaminide, alpha-D-mannoside, alpha-L-fucoside or a-D-glucoside, respectively. These moieties are crucial parts of the recognition sites in cellular glycoconjugates for plant lectins. The extent of staining invariably increased from the basal to the luminal cell layer. No nuclear staining was observed. Within the 18 cases of bladder lesions studied, the appearance of nuclear staining was characteristic of transitional cell carcinoma, its correlation to the histologic grade being dependent on the type of neoglycoprotein. Cytoplasmic staining revealed at least two patterns of grade-dependent variations, namely rather constant expression for lactose-mannose-, fucose- and maltose-specific sites and an initial increased followed by a loss of binding activity at the highest level of cellular atypia for the other three types of probe. Intratumoral heterogeneity was especially visible in tumors of this group. Interestingly, the known positive correlation of presence of the Thomsen-Frieden rich antigen with the level of cellular atypia, monitored with peanut agglutinin, could be extended to the expression of respective receptor sites, which was experimentally feasible due to the synthesis of this disaccharide structure and its immobilization to the carrier protein.

Arachis↗

PubMedDate not supplied

Multiple differences between wild-type B16 melanoma cells and a wheat germ agglutinin resistant clone.

A low-metastatic, glycosylation-defective variant of the B16 murine melanoma was obtained by Tao and Burger (1977) through selection with wheat germ agglutinin. We found that variant and parental (wild-type) cell lines were equally invasive when confronted with precultured embryonic chick heart fragments in vitro. Also, a short-term in vivo arrest assay showed no significant differences. After intravenous injection, wild-type cells killed the recipient mice faster than did the variant cells. We were able to confirm the changes in glycosylation at the enzyme level. In addition, we showed that the pattern of endogenous lectins was strikingly different, at least at the quantitative level. We also looked at another set of receptor proteins, namely receptors for neurotransmitters coupled to adenylate cyclase. The response to the vasoactive intestinal peptide and prostaglandins was lower in the variant cells, which also had a delayed response to cholera toxin. Although most of the data can be explained by altered glycosylation in the variant cells, the large number of differences between variant and parent cells makes it difficult to identify the biochemical basis of altered metastatic behaviour. This might also be the case with other pairs of cells differing in metastatic activity.

Animals↗

PubMedDate not supplied

Establishment, characterization and determination of cell surface sugar receptor (lectin) expression by neoglycoenzymes of a human myeloid marker-expressing B lymphoblastoid cell line.

Mediation of cellular interactions by protein (lectin)-carbohydrate recognition presupposes the expression of respective surface determinants. Due to the importance of cellular contacts between bone marrow stromal cells, recently shown to express cell surface lectins, and tumor or normal progenitor cells for biosignaling and marrow egress, quantitation of cell surface sugar receptor expression by a panel of chemically glycosylated enzymes (tetrameric E. coli beta-galactosidase) for human leukemia/lymphoma cells was initiated. Cells of the new B lymphoblastoid line Croco II that are partially positive for the CD15-specific epitope expressed receptors for various sugar specificities on their surface, fulfilling an indispensable prerequisite for establishment of glycobiological interactions. Binding studies with increasing neoglycoenzyme concentrations up to saturation in four cases disclosed values for apparent affinity constants in the range of 25-200 nM with 0.25-3 x 10(5) bound probes per cell. The presence of receptors for constituents of carbohydrate chains of cellular glycoconjugates was also ascertained biochemically, namely for beta-galactosides, alpha-mannosides, alpha-fucosides and N-acetylgalactosaminides. Expression of this property was modulated by changes in the culture conditions, as revealed by binding studies with cells, derived from growth in medium containing different serum concentrations. These findings indicate that cell surface sugar receptors of tumor cells warrant further attention with respect to recognitive interactions.

Antigens, CD↗

PubMedDate not supplied

Localization of endogenous sugar-binding proteins (lectins) in tumors of the central and peripheral nervous system by biotinylated neoglycoproteins.

The carbohydrate part of cellular glycoconjugates - glycoproteins, glycoproteins, glycolipids and proteoglycans - and specific endogenous sugar receptors, i.e. lectins, can establish a system of biological recognition based on protein-sugar interactions on the cellular and subcellular levels. To gain insight into the role of proteins in this type of interaction, sections of surgically removed tumor specimens of central and peripheral nervous tissue were analyzed glycohistochemically, using biotinylated neoglycoproteins with different sugar part. A specific staining with this type of probe, exposing different sugar moieties as ligands, indicated the presence of sugar receptors in different types of meningiomas, glioblastomas, gangliocytomas, anaplastic and well-differentiated oligodendrogliomas and ependymomas as well as in neurinomas and neurofibromas of peripheral nerves. In comparison to the well-differentiated ependymomas, the anaplastic form of this tumor exhibited a generally higher capacity to specifically bind the neoglycoproteins, containing alpha- or beta-glucosides. Inverse intensity of the glycohistochemical reaction was observed with galactose-6-phosphate-, galactose-beta(1.3)-N-acetylglucosamine-N-acetyl-D-glucosamine- and mannose- (BSA- biotin), respectively, when anaplastic and differentiated oligodendrogliomas were compared with each other. Tumorously dedifferentiated neurons, i.e. in gangliocytomas, showed a changed spectrum of endogenous sugar receptors in comparison to neurons of normal cerebral cortex. Qualitative and quantitative differences of sugar receptors were observed among the distinct subtypes of meningiomas. Receptors for N-acetyl-D-galactosamine were present only in the anaplastic form, while glucuronic acid-specific receptors were only found in the meningotheliomatous meningiomas. Distinctions in binding spectrum of neoglycoproteins suggest the presence of a possible additional subtype of meningiomas, called submalignant meningioma. Analysis of the spectrum of endogenous sugar receptors can serve to distinguish between different cell populations composing a given tumor, as shown in neurofibromas in the cases of Schwann cells and fibroblastoid cells stained with N-acetyl-D-glucosamine-(BSA-biotin). The analysis of expression of endogenous sugar receptors, as part of an intercellular information code system, may represent a further way of studying the mechanism of tumor differentiation and propagation.

Biotin↗

PubMedDate not supplied

Influence of treatment with the immunomodulatory effective dose of the beta-galactoside-specific lectin from mistletoe on tumor colonization in BALB/c-mice for two experimental model systems.

Mistletoe extracts have approval for clinical application. This warrants the quest for the definition of the active substances to optimize their application. Thus, the extent of immunomodulating and antimetastatic activity of the beta-galactoside-specific lectin from mistletoe extract (ML I) was investigated. In BALB/c-mice regular subcutaneous (s.c.) injections of small nontoxic doses of ML I yielded significant enhancement of peritoneal macrophage activity, as measured in chemiluminescence assays, as well as significant weight gain of thymus. Spleen weight, however, increased without statistical significance. To evaluate the anti-metastatic activity of ML I we intravenously (i.v.) inoculated sarcoma L-1 and fibrosarcoma RAW 117-H 10 cells which cause tumor colonization of lungs and livers in BALB/c-mice, respectively. After regular s.c. administration of ML I, the number of lung and liver tumor colonies significantly decreased in both experimental tumor models as compared to control mice which received injections of saline solution. Accordingly, ML I can be regarded as a potent immunomodulating and antimetastatic substance, which seems to be promising for clinical trials in human oncology.

Adjuvants, Immunologic↗

PubMedDate not supplied

Glycohistochemistry of endogenous lectins in cutaneous cancer.

Plant lectins have been applied to define the profile of certain carbohydrate determinants in routinely processed sections of specimens from cutaneous neoplasia. To facilitate detection of endogenous receptors with specificity to carbohydrates, termed endogenous lectins, biotinylated neoglycoproteins (glycoproteins derived from chemical glycosylation of a histochemically inert carrier protein) were employed on formalin-fixed, paraffin-embedded sections of 40 cases of cutaneous cancer. These included 20 cases of basal cell epithelioma and 10 cases of squamous cell carcinoma as well as 10 cases of malignant melanoma. A mixed pattern of staining extent was seen for the different types of neoglycoproteins. Glycohistochemical controls ascertained that endogenous lectins with specificity for alpha- or beta-galactosides, alpha-mannosides, alpha-fucosides and alpha-glucosides, respectively, bound the neoglycoproteins. Initial biochemical purification from one case of basal cell epithelioma revealed the molecular characteristics of the endogenous beta-galactoside-specific and alpha-mannoside-specific lectins.

Carbohydrates↗

PubMedDate not supplied

Regulation of distribution, amount and ligand affinity of sugar receptors in human colon carcinoma cells by treatment with sodium butyrate, retinoic acid and phorbol ester.

Human colon carcinoma cells were treated with non-toxic levels of sodium butyrate, retinoic acid or phorbol ester, eliciting characteristic growth inhibition and morphological changes. Since protein-carbohydrate interactions are supposedly involved in regulatory processes and can serve within targeted drug delivery, the capacity to bind components of the carbohydrate chains of cellular glycoconjugates was monitored for such cells in relation to the type of the medium additive. The pattern of binding of a panel of neoglycoproteins was significantly altered for fixed cells, depending on the type of putative maturation factor. Quantitation of cell surface sugar receptors at a non-saturating concentration of neoglycoenzyme, employed as carbohydrate ligand-exposing probe, led to a similar conclusion. Up to six-fold increases were determined for individual probes. Binding studies with varying concentrations of neoglycoenzymes in the case of four ligands revealed that the receptor density, but not the affinity was significantly affected. Biochemical analyses corroborated this result by demonstrating mainly quantitative differences after affinity chromatography of detergent extracts from the four types of cell pellet. By showing the inhibitory potency of neoglycoprotein-conjugated liposomes in the cell binding assay with neoglycoenzymes, a perspective is indicated, of how the different effects of the differentiation-inducing agents might be beneficially exploited in targeted drug delivery.

Adenocarcinoma↗

PubMedDate not supplied

Elucidation of similarities of sugar receptor (lectin) expression of human lung metastases from histogenetically different types of primary tumors.

Selective interplay between proteins and carbohydrates of cellular glycoconjugates offers the potential to mediate physiologically important biorecognition and biosignaling, relevant to metastasis formation. Biotinylated neoglycoproteins were therefore employed as tools to detect endogenous sugar receptors (lectins) in paraffin-embedded sections of 35 lung metastases from different types of primary tumors. The selection consisted of 17 cases of sarcoma, 11 cases of testicular germ cell tumor, 5 cases of adenocarcinoma, 1 case of melanoma and 1 case of adamanthioma. Receptors with specificity to rhamnose, structurally related to galactose, and N-acetyl-D-galactosamine were present in all or clusters of tumor cells in 27 or 26 of 35 cases. Binding of other carbohydrate constituents of glycoconjugates and of heparin was comparatively lower, ranging from 13 out of 35 cases for L-fucose to 21 out of 35 cases for sialic acid. Regardless of the origin of hte metastatic lesions, the proportions of sugar receptor expression of tumor cells in lung metastases were similar, when the two probes with highest overall extent of binding to tissue sections were applied. Although the influence of the identical microenvironment should not be overlooked, tumor cell homing to a certain target organ may supposedly be reflected in similarities of their profile of receptors for neoglycoproteins, carrying the glycohistochemically decisive constituents of naturally occurring glycoconjugates.

Biotin↗

PubMedDate not supplied

Xenografts from a human colon carcinoma and its metastases: establishment, characterization and differences in the pattern of carbohydrate-binding proteins.

Investigation of the pathogenesis of human colorectal carcinoma metastasis can be rendered experimentally possible by suitable human cell biological model systems. The purpose of these studies was to establish xenografts in nude mice from human colon carcinoma and from its metastasis in the same patient as an appropriate model. Surgically removed biopsy specimens from a colon adenocarcinoma (grade 3) and its local relapse two years later with metastases in the small intestine were established as xenotransplants and their growth characteristics examined. Both tissue types shared common characteristics with respect to marker expression (carcinoembryonic antigen, neuron-specific enolase, cytokeratin). The primary tumor showed remarkable development of necrotic effusion with cytotoxic activity that ceased after several passages. The profile of endogenous carbohydrate-binding proteins (lectins), the receptors for cellular glycoconjugates in a recognitive protein-carbohydrate interplay with potential relevance to metastases formation, revealed differences between these two human tumor samples of identical origin, especially with respect to beta-galactoside-specific receptors. This glycobiochemical analysis employed standardized procedures. Prolonged passaging was also shown to result in profile alterations, as was similarly noted in comparison to another species. These studies may encourage the application of systems of primary tumor and its metastases in the same patient in attempts to correlate the expression of cellular characteristics with the biological and clinical behavior of human colonic tumor cells.

Adenocarcinoma↗