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High‐grade gliomas (HGG) are the most frequent brain tumors in adults. Glioblastoma multiforme (GBM) is their most aggressive form resistant to therapy. It was shown that inhibition of autophagy reduced GBM development and autophagy interfering agents are regarded as a new strategy to fight glioma cells. The lysosome‐associated membrane proteins (LAMPs) display differential expression particularly in cancer. There are few data on their expression and especially on their molecular profile. The aim of the present study is to investigate the expression of LAMP‐1 and LAMP‐2 genes and proteins in HGG. Newly diagnosed patients with HGG and healthy controls were examined by immunohistochemistry and qPCR for both protein and mRNA levels of LAMP‐1 and LAMP‐2. The transcriptional activity of LAMP‐1 in HGG was significantly higher compared to normal brain and to LAMP‐2. The two glycoproteins were detected in the cytosol of tumor cells with varying intensity, LAMP‐1 showing again enhanced expression. In conclusion, novel data on LAMP‐1 overexpression in HGG are presented suggesting involvement of this gene and protein in cell adhesion and tumor progression. These findings might help the elucidation of the complex biological role of the multifunctional LAMPs proteins and to predict novel therapeutic targets in lysosomes. [ABSTRACT FROM AUTHOR]

Endothelial cells are major participants in angiogenic processes accompanying wound repair. The functions of ABH histo-blood group antigens (HBGAs) and lysosome-associated membrane proteins LAMP-1 and LAMP-2 in endothelial cells of granulation tissue are currently unkown. Here we hypothesize that HBGAs and LAMPs enrich the phenotypic characteristics of endothelial cells and might be implicated in the plasticity of granulation tissue. Immunohistochemistry revealed permanent expression of HBGAs in the cytoplasm of endothelial cells of all sprouting capillaries regardless of the organ examined. A modulation in both the localization and the intensity of the signal for LAMPs was observed. Interestingly, LAMP-1 showed a more intensive staining compared to LAMP-2. LAMP-1 was found in the cytoplasm, as well as on plasma membranes of endothelial cells. We present the first comparative immunohistochemical study of the expression of HBGA and LAMPs in endothelial cells of granulation tissue. Novel evidence for modulating LAMP reactivity is reported. Our results suggest that both glycoconjugates might contribute to the process of neoangiogenesis and tissue remodeling in wound healing. [ABSTRACT FROM AUTHOR]

Sarafian, Victoria S., Tomova, Elena S., Kalaydjiev, Svetoslav K. Stomach expression of histo-blood group antigens A and B in some vertebrates.— Acta Zoologica(Stockholm)85: 191 –199Histo-blood group antigens (HBGA) are genetically determined glycoproteins and glycolipids expressed not only on human erythrocytes but also in vertebrate tissues. Direct evidence for the immunobiological importance of their tissue localization in the evolutionary aspect is still lacking.The present study examines the expression of A and B HBGA in the stomach of free-living vertebrates belonging to: Chondrichthyes, Actinopterygii, Amphibia, Reptilia, Aves, and Mammalia.HBGA were detected immunohistochemically on stomach paraffin sections from 11 species. In all classes from Actinopterygii to Mammalia HBGA expression was confined to stomach mucosa only. Antigenic heterogeneity in the pattern of expression and localization was observed. Smooth muscle tissue, endothelial and red blood cells were immunonegative, except for the reptileEmys orbicularis.Our results present the first comparative evidence for the expression of HBGA in the stomach of 11 free-living vertebrate species from six classes, some of which have never been studied so far. It could be assumed that A and B antigens are constant and conservative structures with almost similar tissue localization. Their immunobiological role in the animal gastrointestinal tract might be possibly related to cell differentiation and homeostasis maintenance which would contribute to sustain the evolutionary stable ABH antigen cellular expression. [ABSTRACT FROM AUTHOR]