Targeted O-glycoproteomics for the development of diagnostic markers for advanced colorectal cancer

Global characterization of mouse testis O-glycoproteome landscape during spermatogenesis

Protein O-glycosylation plays critical roles in sperm formation and maturation. However, detailed knowledge on the mechanisms involved is limited due to lacking characterization of O-glycoproteome of testicular germ cells. Here, we performed a systematic analysis of site-specific O-glycosylation in mouse testis, and established an O-glycoproteome map with 349 O-glycoproteins and 799 unambiguous O-glycosites. Moreover, we comprehensively investigated the distribution properties of O-glycosylation in testis and identified a region near the N-terminal of peptidase S1 domain that is susceptible to O-glycosylation. Interestingly, we found dynamic changes with an increase Tn and a decrease T structure from early to mature developmental stages. Notably, the importance of O-glycosylation was supported by its effects on the stability, cleavage, and interaction of acrosomal proteins. Collectively, these data illustrate the global properties of O-glycosylation in testis, providing insights and resources for future functional studies targeting O-glycosylation dysregulation in male infertility.

Lectin-modified drug delivery systems - Recent applications in the oncology field

Chemotherapy with cytotoxic drugs remains the core treatment for cancer but, due to the difficulty to find general and usable biochemical differences between cancer cells and normal cells, many of these drugs are associated with lack of specificity, resulting in side effects and collateral cytotoxicity that impair patients' adherence to therapy. Novel cancer treatments in which the cytotoxic effect is maximized while adverse effects are reduced can be implemented by developing targeted therapies that exploit the specific features of cancer cells, such as the typical expression of aberrant glycans. Modification of drug delivery systems with lectins is one of the strategies to implement targeted chemotherapies, as lectins are able to specifically recognize and bind to cancer-associated glycans expressed at the surface of cancer cells, guiding the drug treatment towards these cells and not affecting healthy ones. In this paper, recent advances on the development of lectin-modified drug delivery systems for targeted cancer treatments are thoroughly reviewed, with a focus on their properties and performance in diverse applications, as well as their main advantages and limitations. The synthesis and analytical characterization of the cited lectin-modified drug delivery systems is also briefly described. A comparison with free-drug treatments and with antibody-modified drug delivery systems is presented, emphasizing the advantages of lectin-modified drug delivery systems. Main constraints and potential challenges of lectin-modified drug delivery systems, including key difficulties for clinical translation of these systems, and the required developments in this area, are also signalled.

Clinical glycoproteomics: methods and diseases

Glycoproteins, representing a significant proportion of posttranslational products, play pivotal roles in various biological processes, such as signal transduction and immune response. Abnormal glycosylation may lead to structural and functional changes of glycoprotein, which is closely related to the occurrence and development of various diseases. Consequently, exploring protein glycosylation can shed light on the mechanisms behind disease manifestation and pave the way for innovative diagnostic and therapeutic strategies. Nonetheless, the study of clinical glycoproteomics is fraught with challenges due to the low abundance and intricate structures of glycosylation. Recent advancements in mass spectrometry-based clinical glycoproteomics have improved our ability to identify abnormal glycoproteins in clinical samples. In this review, we aim to provide a comprehensive overview of the foundational principles and recent advancements in clinical glycoproteomic methodologies and applications. Furthermore, we discussed the typical characteristics, underlying functions, and mechanisms of glycoproteins in various diseases, such as brain diseases, cardiovascular diseases, cancers, kidney diseases, and metabolic diseases. Additionally, we highlighted potential avenues for future development in clinical glycoproteomics. These insights provided in this review will enhance the comprehension of clinical glycoproteomic methods and diseases and promote the elucidation of pathogenesis and the discovery of novel diagnostic biomarkers and therapeutic targets.

Pharmacological properties of extracts and prenylated isoflavonoids from the fruits of Osage orange (Maclura pomifera (Raf.) C.K.Schneid.)

Osage orange trees (Maclura pomifera (Raf.) C.K.Schneid.) are distributed worldwide, particularly in south-east states of the USA. They produce large quantities of strong yellow fruits, bigger than oranges, but these fruits are inedible, with an acid milky juice which is little consumed by birds and insects. Extracts prepared from Osage orange fruits (hedge apple) have revealed a range of pharmacological properties of interest in human and veterinary medicine. In addition, Osage orange extracts can be used in agriculture and aquaculture, and as dyeing agent for the textile industry. Extracts contain potent antioxidant compounds, notably the isoflavonoids pomiferin and auriculasin, together with other terpenoids and flavonoids. The structural characteristics and pharmacological properties of the major prenylated isoflavones isolated from M. pomifera are discussed here, with a focus on the two phenolic compounds osajin and warangalone, and the two catechol analogues pomiferin and auriculasin. The mechanisms at the origin of their potent antioxidant and anti-inflammatory effects are presented, notably inhibition of xanthine oxidase, phosphodiesterase 5A and kinases such as RKS2 and kRAS. Osajin and auriculasin display marked anticancer properties, owing to their ability to inhibit tumor cell proliferation, migration and tumor angiogenesis. Different molecular mechanisms are discussed, including osajin‑copper complexation and binding to quadruplex DNA. An overview of the mechanism of action of the prenylated isoflavones from Osage orange is presented, with the objective to promote their knowledge and to raise opportunities to better exploit the fruits of Osage orange, abundant but largely neglected at present.

Towards chemoenzymatic labeling strategies for profiling protein glycosylation

Protein glycosylation is one of the most common and important post-translational modifications of proteins involved in regulating glycoprotein functions. The chemoenzymatic glycan labeling strategy allows rapid, efficient, and selective interrogation of glycoproteins. Glycoproteomics identifies protein glycosylation events at a large scale, providing information such as peptide sequences, glycan structures, and glycosylated sites. This review discusses the recent development of chemoenzymatic labeling strategies for glycoprotein analysis, mainly including glycoprotein and glycosite profiling. Furthermore, we highlight the chemoenzymatic enrichment approaches in mass spectrometry analysis for three classes of glycan modifications, including N-glycosylation, O-GlcNAcylation, and mucin-type O-glycosylation. Finally, we highlight the emerging trends in new tools and cutting-edge technologies available for glycoproteomic research.

Protein glycosylation in lung cancer from a mass spectrometry perspective

Lung cancer is a severe disease for which better diagnostic and therapeutic approaches are urgently needed. Increasing evidence implies that aberrant protein glycosylation plays a crucial role in the pathogenesis and progression of lung cancer. Differences in glycosylation patterns have been previously observed between healthy and cancerous samples as well as between different lung cancer subtypes, which suggests untapped diagnostic potential. In addition, understanding the changes mediated by glycosylation may shed light on possible novel therapeutic targets and personalized treatment strategies for lung cancer patients. Mass spectrometry based glycomics and glycoproteomics have emerged as powerful tools for in-depth characterization of changes in protein glycosylation, providing valuable insights into the molecular basis of lung cancer. This paper reviews the literature on the analysis of protein glycosylation in lung cancer using mass spectrometry, which is dominated by manuscripts published over the past 5 years. Studies analyzing N-glycosylation, O-glycosylation, and glycosaminoglycan patterns in tissue, serum, plasma, and rare biological samples of lung cancer patients are highlighted. The current knowledge on the potential utility of glycan and glycoprotein biomarkers is also discussed.

Mass Spectrometry Strategies for O-Glycoproteomics

Glycoproteomics has accelerated in recent decades owing to numerous innovations in the analytical workflow. In particular, new mass spectrometry strategies have contributed to inroads in O-glycoproteomics, a field that lags behind N-glycoproteomics due to several unique challenges associated with the complexity of O-glycosylation. This review will focus on progress in sample preparation, enrichment strategies, and MS/MS techniques for the identification and characterization of O-glycoproteins.