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Established restorative protocols for patients after head and neck radiotherapy are lacking, increasing the failure rates of dental adhesive restorations. The purpose of this systematic review and meta-analysis was to analyze the evidence regarding the impact of head and neck radiotherapy on the longevity of dental adhesive restorations. A search was performed using PubMed, Scopus, and Embase in May 2018 (updated in November 2020). Data extraction was performed regarding the percentage of restoration failure among dental adhesive materials, including glass ionomer cements, resin-modified glass ionomer cements, and composite resins. Risk of bias was assessed by the meta-analysis of statistics assessment and review instrument (MAStARI). Confidence in cumulative evidence was evaluated by the Grading of Recommendation, Assessment, Development, and Evaluation (GRADE) protocol. Four studies met the inclusion criteria. All included studies were classified as having a moderate risk of bias and reported results regarding class V restorations. Overall, composite resins presented lower failure rates at 2 years (30%) when compared with resin-modified glass ionomer (41%) and glass ionomer cements (57%). Meta-analysis showed that the risk of failure with glass ionomer cements was greater than with resin-modified glass ionomer cements (RR: 1.71, P <.001). Composite resins presented lower risk of failure when compared with glass ionomer (RR: 2.29, P <.001) and resin-modified glass ionomer cements (RR: 1.30, P =.03). Three studies reported results regarding fluoride compliance, which had a negative effect on the survival rates of glass ionomer and resin-modified glass ionomer cements and a positive effect on composite resin restorations. The results suggest that composite resin restorations associated with fluoride gel compliance seems to be the best alternative for restoring class V lesions in patients after head and neck radiotherapy. However, the results showed moderate certainty of evidence, which justifies the need for more randomized clinical trials regarding this subject. [ABSTRACT FROM AUTHOR]

We aimed to find biomarkers of progression from oral leukoplakias (OL) to oral squamous cell carcinoma (OSCC) using the noninvasive liquid biopsy of tear fluids. Unstimulated tears from patients with OL (N=10), proliferative verrucous leukoplakia (PVL) (N=10), OSCC (n=14), and control patients (N=10) were collected and submitted to discovery-based proteomics by liquid chromatography-tandem mass spectrometry (LC-MS/MS). The data were analyzed by the software MaxQuant (proteomics), Byonics (N-glycoproteomics), and PEAKS database (post-translational modifications) (ANOVA following the Tukey test assuming p<0.05). Proteomic data were integrated with analysis of public databases to validate the findings. We identified a panel of proteins with differential abundance among the groups that present the potential capacity to predict malignant transformation. Many proteins are correlated with clinicopathological features, such as epithelial dysplasia, lymph node metastasis, and clinical stages of the disease. In addition, using public databases we demonstrated that some proteins identified in our panel of biomarkers are druggable and may be useful as therapeutic targets. Liquid biopsy from tear fluids may be a powerful noninvasive tool to provide insights into the biology of OSCC. Financial Support: FAPESP 22/04490-1. [ABSTRACT FROM AUTHOR]

Iron–peptide complexes have been considered a promising source of more bioavailable iron, with reduced side effects as compared to iron salts. Whey protein isolate (WPI) hydrolyzed by alcalase, pancreatin or flavourzyme was ultrafiltered (cut off 5 kDa) and their fractions – retentates and filtrates – were evaluated for iron-binding capacity. The Fe–hydrolysate complexation reaction resulted in a dramatic increase in iron solubility at pH 7.0, from 0% to almost 100%. This result was obtained regardless of the molecular mass profile or the enzyme used to obtain the samples. Fractions from hydrolysate obtained with pancreatin (HP) were chosen to continue the study. The complexes formed with both fractions from HP were stable under simulated gastric digestion (50.8–89.4%). To identify the peptides with iron-binding capacity, the HP fractions were isolated by IMAC-Fe 3 + , and the retentate showed higher relative concentrations of iron-binding peptides than the filtrate. Iron-binding peptide sequencing, accomplished by LC–MS/MS, showed Glu and/or Asp in all the sequences, and their carboxylic groups were amongst the main iron-binding sites. WPI hydrolysis with pancreatin yields peptides that can form iron complexes with the potential to increase iron bioavailability and reduce its pro-oxidant effect. [ABSTRACT FROM AUTHOR]

Abstract: Secreted class III peroxidases (EC 1.11.1.7) are implicated in a broad range of physiological processes throughout the plant life cycle. However, the unambiguous determination of the precise biological role of an individual class III peroxidase isoenzyme is still a difficult task due to genetic redundancy and broad substrate specificity in vitro. In addition, many difficulties are encountered during extraction and analysis of cell wall proteins. Since class III peroxidases are also secreted into the apoplast, the use of suspension cell cultures can facilitate isolation and functional characterization of individual isoforms. Here, we report on the characterization of class III peroxidases secreted in the spent medium of sugarcane suspension cell cultures. After treatment with specific inducers of cell wall lignification, peroxidases were isolated and activities assayed with guaiacol, syringaldazine and coniferyl alcohol. Enzymatic activity was not significantly different after treatments, regardless of the substrate, with the exception of methyl-jasmonate treatment, which led to a decreased guaiacol peroxidase activity. Remarkably, peroxidases isolated from the medium were capable of oxidizing syringaldazine, an analog to sinapyl alcohol, suggesting that sugarcane cultures can produce peroxidases putatively correlated to lignification. A proteomic approach using activity staining of 2-DE gels revealed a complex isoperoxidase profile, composed predominantly of cationic isoforms. Individual spots were excised and analyzed by LC-ESI-Q-TOF and homology-based search against the Sugarcane EST Database resulted in the identification of several proteins. Spatio-temporal expression pattern of selected genes was determined for validation of identified class III peroxidases that were preferentially expressed during sugarcane stem development. [Copyright &y& Elsevier]

Abstract The mitochondrial phosphate-activated glutaminase C (GAC) is produced by the alternative splicing of the GLS gene. Compared to the other GLS isoform, the kidney-type glutaminase (KGA), GAC is more enzymatically efficient and of particular importance for cancer cell growth. Although its catalytic mechanism is well understood, little is known about how post-translational modifications can impact GAC function. Here, we identified by mass spectrometry a phosphorylated serine at the GLS N-terminal domain (at position 95) and investigated its role on regulating GAC activity. The ectopic expression of the phosphomimetic mutant (GAC.S95D) in breast cancer cells, compared to wild-type GAC (GAC.WT), led to decreased glutaminase activity, glutamine uptake, glutamate release and intracellular glutamate levels, without changing GAC sub-cellular localization. Interestingly, cells expressing the GAC.S95D mutant, compared to GAC.WT, presented decreased migration and vimentin level, an epithelial-to-mesenchymal transition marker. These results reveal that GAC is post-translationally regulated by phosphorylation, which affects cellular glutamine metabolism and glutaminase-related cell phenotype. Graphical abstract Image 1 Highlights • We identified by mass spectrometry a phosphorylation site in the serine 95 of human glutaminase C (GAC) expressed in breast cancer cells. • The mutant GAC.S95D has diminished glutaminase activity. • Cells expressing GAC.S95D have decreased glutaminase activity, glutamine uptake, glutamate secretion and intracellular glutamate levels. • Cells expressing GAC.S95D presented reduction on vimentin and migration. [ABSTRACT FROM AUTHOR]

Over the years, several tumor biomarkers have been suggested to foresee the prognosis oral squamous cell carcinoma (OSCC) patients. Here, we present a systematic review to identify, evaluate and summarize the evidence for OSCC reported markers. Eligible studies were identified through a literature search of MEDLINE/PubMed until January 2016. We included primary articlesreporting overall survival, disease-free survival and cause-specific survival as outcomes. Our findings were analysed using REporting recommendations for tumor MARKer prognostic studies (REMARK), QuickGo tool and SciCurve trends. We found 41 biomarkers, mostly proteins evaluated by immunohistochemistry. The selected studies are of good quality, although, any study referred to a sample size determination. Considering the lack of follow-up studies, the molecules are still potential biomarkers. Further research is required to validate these biomarkers in well-designed clinical cohort-based studies. [ABSTRACT FROM AUTHOR]

To integrate all the available data published in the English literature regarding the protein diagnostic and/or prognostic markers in salivary gland tumors identified by mass spectrometry (MS)-based discovery proteomics. An extensive search was carried out using MEDLINE/PubMed, EMBASE, Web of Science, and Scopus databases. Manual searching in Google Scholar and assessment of the reference list of the included articles also was performed. The risk of bias was assessed by the Joanna Briggs Institute Critical Appraisal tool for the specific type of study. A total of 1092 articles were initially retrieved within which 6 were used for data extraction, resulting in 145 cases of salivary gland tumors. The data was composted by eleven salivary gland tumor types. In total, 2136 proteins were detected by MS-based discovery proteomics in salivary gland tumors. Ninety-one proteins were proposed as potential diagnostic and/or prognostic markers. Of these, some have been identified in one or more studies, whereas fifteen were in common across studies and a total of seventy-six were non-repeat proteins. In summary, we compiled data about the proteomic profile of potential diagnostic and/or prognostic protein markers of the salivary gland tumors detected by MS-based discovery proteomics. The proteins ANXA1, ANXA5, CAPG, CRYAB, FGB, GNB2L1, IGHG1, PPIA, S100A9, and SOD1 were proposed as the most common potential diagnostic markers of salivary gland tumors. [Display omitted] • Sample type and mass spectrometry methods influence protein detection. • Standardization is essential for proteomic analysis in salivary gland tumors. • Proteins characterized as markers in salivary gland tumors exhibit similar biological processes. [ABSTRACT FROM AUTHOR]

The phosphate-dependent transition between enzymatically inert dimers into catalytically capable tetramers has long been the accepted mechanism for the glutaminase activation. Here, we demonstrate that activated glutaminase C (GAC) self-assembles into a helical, fiber-like double-stranded oligomer and propose a molecular model consisting of seven tetramer copies per turn per strand interacting via the N-terminal domains. The loop 321LRFNKL326 is projected as the major regulating element for self-assembly and enzyme activation. Furthermore, the previously identified in vivo lysine acetylation (Lys311 in humans, Lys316 in mouse) is here proposed as an important down-regulator of superoligomer assembly and protein activation. Bis-2-(5-phenylacetamido-1,3,4-thiadiazol-2-yl)ethyl sulfide, a known glutaminase inhibitor, completely disrupted the higher order oligomer, explaining its allosteric mechanism of inhibition via tetramer stabilization. A direct correlation between the tendency to self-assemble and the activity levels of the three mammalian glutaminase isozymes was established, with GAC being the most active enzyme while forming the longest structures. Lastly, the ectopic expression of a fiber-prone superactive GAC mutant in MDA-MB 231 cancer cells provided considerable proliferative advantages to transformed cells. These findings yield unique implications for the development of GAC-oriented therapeutics targeting tumor metabolism. [ABSTRACT FROM AUTHOR]

Abstract: Class III peroxidases are present as large multigene families in all land plants. This large number of genes together with the diversity of processes catalyzed by peroxidases suggests possible functional specialization of each isoform. However, assigning a precise role for each individual peroxidase gene has continued to be a major bottleneck. Here we investigated the enzyme activity and translational profile of class III peroxidases during stem development of sugarcane as a first step in the estimation of physiological functions of individual isoenzymes. Internodes at three different developmental stages (young, developing and mature) were divided into pith (inner tissue) and rind (outer tissue) fractions. The rind of mature internodes presented the highest enzymatic activity and thus could be considered the ideal tissue for the discovery of peroxidase gene function. In addition, activity staining of 2DE gels revealed different isoperoxidase profiles and protein expression regulation among different tissue fractions. In-gel tryptic digestion of excised spots followed by peptide sequencing by LC-MS/MS positively matched uncharacterized peroxidases in the sugarcane database SUCEST. Multiple spots matching the same peroxidase gene were found, which reflects the generation of more than one isoform from a particular gene by post-translational modifications. The identified sugarcane peroxidases appear to be monocot-specific sequences with no clear ortholog in dicot model plant Arabidopsis thaliana. [Copyright &y& Elsevier]

Summary MAF1 is the main RNA polymerase (Pol) III repressor that controls cell growth in eukaryotes. The Citrus ortholog, CsMAF1, was shown to restrict cell growth in citrus canker disease but its role in plant development and disease is still unclear. We solved the crystal structure of the globular core of CsMAF1, which reveals additional structural elements compared with the previously available structure of hMAF1, and explored the dynamics of its flexible regions not present in the structure. CsMAF1 accumulated in the nucleolus upon leaf excision, and this translocation was inhibited by auxin and by mutation of the PKA phosphorylation site, S45, to aspartate. Additionally, mTOR phosphorylated recombinant CsMAF1 and the mTOR inhibitor AZD8055 blocked canker formation in normal but not CsMAF1-silenced plants. These results indicate that the role of TOR on cell growth induced by Xanthomonas citri depends on CsMAF1 and that auxin controls CsMAF1 interaction with Pol III in citrus. [ABSTRACT FROM AUTHOR]