Role of GD3 Synthase ST8Sia I in Cancers

Simple Summary

The carbohydrate moiety of cell surface glycolipids is modified in cancers of neuro–ectoderm origin, leading to the expression of more complex structures with two or more sialic acid residues. These alterations result from the upregulation of the ST8SIA1 gene that encodes GD3 synthase, the enzyme controlling the biosynthesis of complex gangliosides, and are usually associated with a more aggressive phenotype and a poor outcome for patients, making GD3 synthase an interesting target for cancer therapy. This review reports our general knowledge of GD3 synthase gene expression and regulation, its role in both epithelial–mesenchymal transition (EMT) and cancer progression, and the different approaches targeting GD3S expression in cancers.

Abstract

GD3 synthase controls the biosynthesis of complex gangliosides, bearing two or more sialic acid residues. Disialylated gangliosides GD3 and GD2 are tumor-associated carbohydrate antigens (TACA) in neuro–ectoderm-derived cancers, and are directly involved in cell malignant properties, i.e., migration, invasion, stemness, and epithelial–mesenchymal transition. Since GD3 and GD2 levels are directly linked to GD3 synthase expression and activity, targeting GD3 synthase appears to be a promising strategy through which to interfere with ganglioside-associated malignant properties. We review here the current knowledge on GD3 synthase expression and regulation in cancers, and the consequences of complex ganglioside expression on cancer cell signaling and properties, highlighting the relationships between GD3 synthase expression and epithelial–mesenchymal transition and stemness. Different strategies were used to modulate GD3 synthase expression in cancer cells in vitro and in animal models, such as inhibitors or siRNA/lncRNA, which efficiently reduced cancer cell malignant properties and the proportion of GD2 positive cancer stem cells, which are associated with high metastatic properties, resistance to therapy, and cancer relapse. These data show the relevance of targeting GD3 synthase in association with conventional therapies, to decrease the number of cancer stem cells in tumors.

Exploring the Potential of β-Catenin O-GlcNAcylation by Using Fluorescence-Based Engineering and Imaging

Monitoring glycosylation changes within cells upon response to stimuli remains challenging because of the complexity of this large family of post-translational modifications (PTMs). We developed an original tool, enabling labeling and visualization of the cell cycle key-regulator β-catenin in its O-GlcNAcylated form, based on intramolecular Förster resonance energy transfer (FRET) technology in cells. We opted for a bioorthogonal chemical reporter strategy based on the dual-labeling of β-catenin with a green fluorescent protein (GFP) for protein sequence combined with a chemically-clicked imaging probe for PTM, resulting in a fast and easy to monitor qualitative FRET assay. We validated this technology by imaging the O-GlcNAcylation status of β-catenin in HeLa cells. The changes in O-GlcNAcylation of β-catenin were varied by perturbing global cellular O-GlcNAc levels with the inhibitors of O-GlcNAc transferase (OGT) and O-GlcNAcase (OGA). Finally, we provided a flowchart demonstrating how this technology is transposable to any kind of glycosylation.

NegFluo, a Fast and Efficient Method to Determine Starch Granule Size and Morphology In Situ in Plant Chloroplasts

Starch granules that accumulate in the plastids of plants vary in size, shape, phosphate, or protein content according to their botanical origin. Depending on their size, the applications in food and nonfood industries differ. Being able to master starch granule size for a specific plant, without alteration of other characteristics (phosphate content, protein content, etc.), is challenging. The development of a simple and effective screening method to determine the size and shape of starch granules in a plant population is therefore of prime interest. In this study, we propose a new method, NegFluo, that combines negative confocal autofluorescence imaging in leaf and machine learning (ML)-based image analysis. It provides a fast, automated, and easy-to-use pipeline for both in situ starch granule imaging and its morphological analysis. NegFluo was applied to Arabidopsis leaves of wild-type and ss4 mutant plants. We validated its accuracy by comparing morphological quantifications using NegFluo and state-of-the-art methods relying either on starch granule purification or on preparation-intensive electron microscopy combined with manual image analysis. NegFluo thus opens the way to fast in situ analysis of starch granules.

Studies of viomycin, an anti-tuberculosis antibiotic: copper(ii) coordination, DNA degradation and the impact on delta ribozyme cleavage activity

Viomycin is a basic peptide antibiotic, which is among the most effective agents against multidrug-resistant tuberculosis.

Clustering of Staphylococcus aureus bovine mastitis strains from regions of Central-Eastern Poland based on their biochemical and genetic characteristics

Staphylococcus aureus strains were isolated from mastitic milk of cows with infected mammary glands. The animals were living in 12 different farms near Lublin, in Central-Eastern Poland. A biochemical identification method based on enzymatic assay was performed, followed by haemolytic and proteolytic tests. PCR-RFLP targeted on the gap gene allowed the genetic identification of strains at the species level and verified phenotypic identification results. A molecular typing method using triplex PCR was performed to recognize the genetic similarity of the analyzed strains. DNA microarray hybridization (StaphyType, Alere Technologies) was used for detection of antibiotic resistance and virulence associated markers. The results obtained indicate high genetic similarity in strains isolated from the same sites. High genetic similarities were also detected between strains isolated from cows from different farms of the same region. A slightly lower similarity was noted however, in strains from various regions indicating that the strains are herd specific and that the cow's infections caused by S. aureus were of a clonal character. In 21 representative isolates selected for DNA-microarray testing, only fosfomycin (fosB) and penicillin resistance markers (blaZ, blaI, blaR) were detected. The presence of genes coding for haemolysins (lukF, lukS, hlgA, hla, hld, hlb), proteases (aur, sspA, sspB, sspP), enterotoxins (entA, entD, entG, entI, entJ, entM, entN, entO, entR, entU, egc-cluster), adhesins (icaA, icaC, icaD, bbp, clfA, clfB, fib, fnbA, map, vwb) or immune evasion proteins (scn, chp, sak) was common and, with exceptions, matched triplex PCR-defined clusters.

Applicability of endoscopic examination as a diagnostic approach in urinary tract ailments in dogs

The purpose of this study was to evaluate the applicability of endoscopic examination as a diagnostic method in urethra and bladder ailments in dogs. The experiment involved 60 dogs of different breeds and gender, weighing from 5 to 65 kg, aged between 7 months and 12 years. The dogs were divided into two groups. Group I consisted of clinically healthy animals on which all the lower urinary tract endoscopic examinations described in the literature as well as biopsies of mucosa were performed. Group II consisted of clinical patients, on which endoscopic diagnostic examination was conducted and, on some of them, biopsies for histopathologic examination were made. The results of the experiment suggest that the lower urinary track endoscopy is a suitable diagnostic technique for recognition and differentiation of mucosa inflammation, establishment of causes of haematuria, diagnostics of neoplasms and detection of the existence of an ectopic ureter. Biopsy and histopathologic examination improved the diagnostic value of endoscopy. The techniques tested in our study, inclusive of more invasive method like PPC and cystoscopy on males preceded by the perineal urethrotomy, enable doctors to perform the lower urinary tract endoscopic examination on dogs, especially up to 5 kg. regardless of their gender.

Persistent skin colonization with Staphylococcus aureus in atopic dermatitis: relationship to clinical and immunological parameters

BACKGROUND

Staphylococcus aureus has important implications for the pathogenesis of atopic dermatitis (AD). In some patients S. aureus can be eradicated from the skin during anti-inflammatory treatment, while in others bacterial colonization is persistent. Potential mechanisms and features of these two distinct groups of patients are not known.

OBJECTIVE

Accordingly, we studied relationships between the ability to eliminate S. aureus during an anti-inflammatory treatment and selected clinical and immunological features.

METHODS

Quantitative assessment of S. aureus on the skin, in nasal vestibule and throat, serum IgE levels, CD4/CD8 T-cell ratio, lymphocyte proliferation and phagocyte oxidative burst were determined during the exacerbation and after 4 and 12 weeks of the treatment using topical steroid and oral antihistamine in 34 patients with AD.

RESULTS

S. aureus was found on the skin of all 34 patients during exacerbation. Disease severity scoring of atopic dermatitis (SCORAD) correlated with the density of bacteria. Treatment with oral antihistamine and topical steroid resulted in a significant alleviation of symptoms, which correlated with the elimination of S. aureus from the skin in 70% of patients. In the remaining 30% of patients, dense (more than 10(10)/cm2) S. aureus skin colonization, persisted despite the treatment. Patients with persistent S. aureus presented with higher serum IgE levels, lower lymphocyte proliferation in response to staphylococcal enterotoxin B, phytohaemagluttinin and anti-CD3. Persistence of S. aureus was more common in men.

CONCLUSIONS

Patients with AD differ in the ability to clear S. aureus from the skin during anti-inflammatory treatment, which appears to be related to the abnormalities in immunological parameters. Local antibiotic therapy should be considered only in patients with persistent S. aureus colonization.

Laparoscopic cryptorchidectomy in dogs --report of 15 cases

The study aimed at determining the usability of laparoscopic cryptorchidectomy in treating cases of simple cryptorchidism and neoplastic testes in dogs. The presence of one or both testes inside the peritoneal cavity was confirmed in this study by an ultrasonographic examination employing the use of a 6.5 MHz convex head. The surgeries were conducted on a group of 15 dogs. In 12 subjects a one-sided cryptorchidism was found, 9 of which had right-sided cryptorchidism. In 3 dogs, both-sided cryptorchidism was observed. In 3 cases, an increase in the size of the abdominal testes with the symptoms of hyperestrogenism and feminisation raised a suspicion of neoplastic changes (SCT) taking place, which was confirmed by a histopathological examination. A laparoscopic cryptorchidectomy with intracorporal ligation was performed in all the subjects. The spermatic cord and ductus deferens were occluded with a ligature of an absorbable material, and a manually applied knot.

Proteolytic activity of Staphylococcus aureus strains isolated from the colonized skin of patients with acute-phase atopic dermatitis

Staphylococcus aureus strains isolated from the colonized skin lesions of 26 patients with acute-phase atopic dermatitis were reported to produce various extracellular proteolytic enzymes. Using the skim-milk-agar culture plating method, it was shown that 97% of the strains (65 of 67 examined) produced proteolytic activity, with 61% (42 strains) producing activity comparable to that of the proteolytically hyperactive reference strain Staphylococcus aureus V8. This observation was confirmed by azocasein degradation with culture supernatants, which indicated that 91% of the strains produced extracellular proteinases and 43% exceeded the 2% activity threshold of the reference strain. Control strains were isolated from the nose vestibules of 18 healthy carriers; the proteolytic activity of these strains never exceeded 2.5% of the activity of the reference strain. In 54% of the patients examined ( n=14), the activity of the strains was higher than that determined for the isolates from the control group. The combined use of assays incorporating azocasein and a synthetic chromogenic substrate, N-CBZ-Phe-Leu-Glu- pNA, showed that two staphylococcal enzymes, Staphylococcus aureus metalloproteinase (SAMP) and Staphylococcus aureus serine proteinase (SASP), contributed to the total proteolytic activity released by the strains examined. The contribution of each of the two enzymes varied greatly between different isolates. The undamaged skin of the patients was not colonized with Staphylococcus aureus. The presence of several strains with atypical proteinase characteristics was also reported, suggesting the possible involvement of enzymes other than serine- and metallo-proteinases in the proteolytic activity of Staphylococcus aureus. Taken together, the results of the study imply that staphylococcal proteinases may contribute to the pathogenicity of atopic dermatitis.

[Chronic inflammation of the colon: a diagnostic problem]

Chronic inflammation of the colon and rectum with associated diarrhea has become more difficult to diagnose recently. Many etiological factors and different therapeutic outlines need to be carefully discussed and summarized. Based on most recent literature, authors present current data on etiology and specific (case-depended) diagnostic procedures in colitis and proctocolitis.

Two allelic forms of the aureolysin gene (aur) within Staphylococcus aureus

Proteinases of Staphylococcus aureus are emerging as potential virulence factors which may be involved in the pathogenecity of staphylococcal diseases. We describe here the structure of the gene encoding the metalloproteinase referred to as aureolysin. This gene occurs in two allelic forms and is strongly conserved among S. aureus strains, implying the possibility that the proteinase may have important housekeeping functions.

Synthesis, spectral and antimicrobial properties of 5-chloroarylidene aromatic derivatives of imidazoline-4-one

The synthesis of new chloro-benzylidene substituted derivatives of hydantoin and their antimicrobial activity is reported. The structure-activity relationships showed that the antibacterial effect of investigated compounds depends on the distance of the phenyl ring from the amine residue and the kind of substitutes on the phenyl ring. In the investigated group of derivatives, 5-(2-chlorobenzylidene)-2-(4-fluorobenzylamine)-imidazoline-4-one and 5-(2-chlorobenzylidene)-2-(2-phenylethylamine)-imidazoline-4-one showed the best antibacterial activity against Moraxella catarrhalis.

Differential effects of chlorination of bacteria on their capacity to generate NO, TNF-alpha and IL-6 in macrophages

Activated rodent macrophages produce high amounts of nitric oxide (NO). NO as a tumoricidal and defence molecule against intracellular parasites is commonly accepted. However, its role as an obligatory killing factor for extracellular bacteria is controversial. In the present study we stimulated murine peritoneal macrophages by heat-killed bacteria (Staphylococcus aureus, S. epidermidis and Escherichia coli). In some groups bacteria were pretreated with HOCl, to replace the chlorinating system in activated neutrophils that operates as a bactericidal system in vivo. High levels of NO, tumour necrosis factor-alpha (TNF-alpha) and interleukin-6 (IL-6) were detected after stimulation by all non-chlorinated bacteria strains tested. However, after chlorination Gram-positive bacteria lost their ability to induce NO and TNF-alpha, whereas phagocytosis and IL-6 production were not affected by chlorination.

[Clinical evaluation of serious forms of acne treated with autovaccine]

In this paper a clinical assessment of the treatment of serious forms of acne vulgaris with the use of autovaccines containing Propionibacterium strains was presented. It was shown that the associative therapy including parallel administration of both autovaccine and the antibiotic is remarkably efficacious.

[In vitro assessment of metronidazole adapted to the treatment of periodontopathies]

Chemical and biological assessment was done in vitro of a form of metronidazole for application into deep pouches in periodontal diseases. The obtained plates with metronidazole contained 1.4 mg (37%) of pure substance. Comparing the effect of metronidazole release in time against a control plate it was noted that the drug was released during 3 days in similar proportions from the chemical and biological samples.

Erythromycin and penetrating agents containing ointment in acne vulgaris therapy

An ointment containing penetrating agents and erythromycin was devised. The rate of penetration of the antibiotic through the skin and the ointment efficacy in treatment of acne changes caused by Propionibacterium strains in animals were evaluated.

Bacteria in bile of patients with bile duct inflammation

Bile samples taken intraoperatively from 100 patients with three different bile system diseases were subjected to bacteriological analysis. Statistically significant differences between the types of aerobic and anaerobic bacteria present in the bile were found.

Quantitative studies of the flora of the nasal vestibule in relation to nasal carriage of Staphylococcus aureus

Aerobic and anaerobic bacterial flora and yeast flora of the nasal vestibule were studied quantitatively in eight persons who were persistent, transient or non-carriers of Staphylococcus aureus. The nasal flora of all the subjects consisted of lipophilic and non-lipophilic aerobic diphtheroids, propionibacteria and different staphylococcal species. Other micro-organisms, such as Pityrosporum and Candida, micrococci, streptococci and coliforms were found only occasionally. The presence of S. aureus was related to diminished numbers of other staphylococcal strains and of propionibacteria.

Use of a phage set for the ecological typing of coagulase-negative staphylococci

The staphylococcal flora of skin and acne lesions of 98 patients was analysed by the use of phage typing and biotyping methods. It appeared that in some individuals a relatively stable staphylococcal flora was present while others harboured 7 or more different strains. The same S. epidermidis strains were found on different skin sites and in acne lesions of a given individual. Examples of different carriage patterns were given.

Evaluation of a new bacteriophage set for typing of Staphylococcus epidermidis strains

A new set of typing phages was evaluated for typing 821 Staphylococcus epidermidis strains isolated from normal human skin and from acne lesions. This method was compared with two different systems for biochemical differentiation of S. epidermidis. Distinct subgroups of cocci, which differed in phage susceptibility as well as in biochemical properties, were found. A tentative subdivision of S. epidermidis strains by use of 16 phages arranged into four groups is proposed, together with additional biochemical differentiation of non-typable strains.