Binding of neuroendocrine markers and biotinylated sex hormones and the survival in human lung cancer

Introduction to glycopathology: the concept, the tools and the perspectives

Virtual slides

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Analyzing the flow of biological information is a fundamental challenge for basic sciences. The emerging results will then lend themselves to the development of new approaches for medical applications. Toward this end, the products of protein/lipid glycosylation deserve special attention. The covalent attachment of sugars to these carriers means much more than just a change of the carriers’ physicochemical properties. In principle, the ubiquitous presence of glycoconjugates and the close inspection of the particular structural ‘talents’ of carbohydrates provide suggestive evidence for information coding by sugars. In fact, the theoretical number of ‘words’ (oligomers) formed by ‘letters’ (monosaccharides) is by far higher than by using nucleotides or amino acids. In other words, glycans harbor an unsurpassed coding capacity. The cyto- and histochemical detection of dynamic changes in the profile of cellular glycans (glycome, the equivalent of the proteome) by sugar receptors such as antibodies used as tools underscores the suitability of carbohydrates for such a task. The resulting staining patterns can be likened to a molecular fingerprint. By acting as ligand (counterreceptor) for endogenous receptors (tissue lectins), glycan epitopes become partners in a specific recognition pair, and the sugar-encoded information can then be translated into effects, e.g. in growth regulation. Of note, expression of both sides of such a pair, i.e. lectin and cognate glycan, can physiologically be orchestrated for optimal efficiency. Indeed, examples how to prevent autoimmune diseases by regulatory T cells and restrict carcinoma growth by a tumor suppressor attest occurrence of co-regulation. In consequence, these glycans have potential to establish a new class of functional biomarkers, and mapping presence of their receptors is warranted. In this review, the cyto- and histochemical methods, which contribute to explore information storage and transfer within the sugar code, are described. This introduction to the toolbox is flanked by illustrating the application of each type of tool in histopathology, with focus on adhesion/growth-regulating galectins. Together with an introduction to fundamental principles of the sugar code, the review is designed to guide into this field and to inspire respective research efforts.

Binding capacities of two immunomodulatory lectins, carrier-immobilized glycoligands and steroid hormones in lung cancer and the concentration of nitrite/nitrate in pleural effusions

Combined analysis of the binding properties of inflammatory and tumor cells in pleural effusion, and tumor imprints for various carrier-immobilized types of ligands and lectins, and of a biochemical feature of the effusions is performed to extend the characterization of these cells and their activity. In detail, the binding of Viscum album agglutinin (VAA), Urtica dioica agglutinin (UDA), and of carrier-immobilized N-acetyl-D-glucosamine (GlcNAc), lysoganglioside GM1, estradiol, progesterone, testosterone, and hydrocortisone to native specimens consisting of 46 tumor imprints from surgically treated patients with lung cancer and 74 smears of pleural effusion (PE) cells from cancer or non-cancer patients was studied using fluorescence microscopy with Texas red-labeled streptavidin. Among the tested ligands, VAA was found to provide the most effective staining of cells (60-78.1% of positive cases). When compared with inflammatory cells from PE, cancer cells were seen to bind more frequently only two ligands, namely UDA and estradiol. Significant (P < 0.001) difference between patients with bronchial carcinoma and non-cancer patients were found, when the content of NO2-/NO3- in PE fluids was measured. Whereas the level of NO2-/NO3- in PE of non-cancer patients was 12.6 +/- 10.7 microM (n = 12), it was 37.7 +/- 19.4 microM (n = 14) in cancer patients without pleural metastases and 37.5 +/- 16.0 microM (n = 26) in patients with pleural metastases. The level of NO2-/NO3- in PE appeared to correlate with extent of staining with GM1 and GlcNAc: in non-cancer patient groups it was significantly higher (P = 0.032) for negative subjects than those binding the ligand GlcNAc, whereas in the patient group with adenocarcinoma it was significantly lower (P = 0.032) for patients without binding capacities for GlcNAc and GM1. The results obtained suggest that the combined analysis of increased levels of NO2-/NO3- in PE and of glycohistochemical properties of cancer and inflammatory cells may be useful in exploring the interrelationship of functionally important cellular characteristics.

Analysis of tumour necrosis factor alpha-specific, lactose-specific and mistletoe lectin-specific binding sites in human lung carcinomas by labelled ligands

Receptor sites can be visualized by labelled ligands as an alternative to receptor-specific antibodies, as substantiated for two different receptor classes. Recombinant tumour necrosis factor alpha (TNF) was biotinylated via amino-groups and the resultant probe was applied to formalin-fixed, paraffin-embedded tissue sections of 94 primary bronchial carcinomas and to normal peripheral lung parenchyma. In addition, monoclonal antibodies specific for neuron-specific enolase (NSE) and TNF itself were used. The biotinylated beta-galactoside-specific mistletoe lectin, which exhibits dose-dependent immunomodulatory and toxic potency, and two probes that specifically detect certain types of sugar receptors were employed to illustrate further the feasibility of using ligands for receptor localisation. The tumours comprised 62 small cell lung carcinomas, 10 epidermoid carcinomas, 11 adenocarcinomas and 11 large cell anaplastic carcinomas. Expression of TNF-binding sites was found in 39 of the small cell lung carcinomas and in 13 of the non-small cell lung carcinomas. Binding capacity for the TNF-specific antibody was seen in similar proportions of small cell lung carcinomas and of non-small cell lung carcinomas. None of the normal lung parenchymas revealed significant staining. Binding capacities to mistletoe lectin were seen in all normal lung parenchymas and in nearly all cases of adenocarcinoma (10/11). A correlation between the expression of NSE and the binding capacities to TNF was detected. Endogenous lectins, specific for lactose or beta-GalNAc, were displayed in nearly one half of the small cell lung carcinoma cases (44% or 45% respectively) and in about 25% of the non-small cell lung carcinoma cases.