Mutual regulation between glycosylation and transforming growth factor-ß isoforms signaling pathway.

Transforming growth factor-beta (TGF-ß) superfamily members orchestrate a wide breadth of biological processes. Through Sma and Mad (Smad)-related dependent or noncanonical pathways, TGF-ß members involve in the occurrence and development of many diseases such as cancers, fibrosis, autoimmune diseases, cardiovascular diseases and brain diseases. Glycosylation is one kind of the most common posttranslational modifications on proteins or lipids. Abnormal protein glycosylation can lead to protein malfunction and biological process disorder, thereby causing serious diseases. Previously, researchers commonly make comprehensive systematic overviews on the roles of TGF-ß signaling in a specific disease or biological process. In recent years, more and more evidences associate glycosylation modification with TGF-ß signaling pathway, and we can no longer disengage and ignore the roles of glycosylation from TGF-ß signaling to make investigation. In this review, we provide an overview of current findings involved in glycosylation within TGF-ßs and theirs receptors, and the interaction effects between glycosylation and TGF-ß subfamily signaling, concluding that there is an intricate mutual regulation between glycosylation and TGF-ß signaling, hoping to present the glycosylation regulatory patterns that concealed in TGF-ßs signaling pathways.

Machine learning reveals salivary glycopatterns as potential biomarkers for the diagnosis and prognosis of papillary thyroid cancer.

The diagnosis of thyroid cancer, especially papillary thyroid cancer (PTC), is increasing rapidly worldwide. In this study, we aimed to study the glycosylation of salivary proteins associated with PTC and assess the likelihood that salivary glycopatterns may be a potential biomarker of PTC diagnosis. Firstly, 22 benign thyroid nodule (BTN) samples, 27 PTC samples, and 30 healthy volunteers (HV) samples were collected to probe the difference of salivary glycopatterns associated with PTC using lectin microarrays. Then, five machine learning models including K-Nearest Neighbor (KNN), Multilayer Perceptron (MLP), Logistic Regression (LR), Random Forest (RF), and Support Vector Machine (SVM) were established to distinguish HV, BTN and PTC based on the changes of salivary glycopatterns. As a result, SVM had the best diagnostic effect with an accuracy rate of 92 % in testing set. Besides, lectin microarrays were used to explore the differences in salivary glycopatterns of 26 paired salivary samples of PTC patients before and after operation in order to probe into salivary glycopatterns as potential biomarkers for prognosis of PTC patients. The results showed that the levels of salivary glycopatterns recognized by 6 different lectins in patients after the operation almost convergenced with HVs. This study could help to screen and assess patients with PTC and their prognosis based on precise changes of salivary glycopatterns.

Elevation of α-1,3 fucosylation promotes the binding ability of TNFR1 to TNF-α and contributes to osteoarthritic cartilage destruction and apoptosis.

BACKGROUND: Osteoarthritis (OA) is the most common form of arthritis and is characterized by the degradation of articular cartilage and inflammation of the synovial membrane. Fucosylation is an important feature of protein N/O-glycosylation and is involved in a variety of pathological processes, including inflammation and cancer. However, whether fucosylation impacts the OA pathological process is unknown. METHODS: Total proteins were extracted from cartilage samples obtained from patients with OA (n = 11) and OA rabbit models at different time points (n = 12). OA-associated abnormal glycopatterns were evaluated by lectin microarrays and lectin blots. The expression of fucosyltransferases involved in the synthesis of α-1,3 fucosylation was assessed by semi-qPCR. The synthesis of α-1,3 fucosylation mediated by FUT10 was interrupted by the transfection of siRNA, and the effect of α-1,3 fucosylation on OA-associated events was assessed. Then, immunoprecipitation and lectin blotting were used to investigate the relationship between the α-1,3 fucosylation level of tumor necrosis factor receptor superfamily member 1A (TNFR1) and OA. Finally, a TNFR1 antibody microarray was fabricated to evaluate the effect of α-1,3 fucosylation on the ability of TNFR1 to bind to tumor necrosis factor-α (TNF-α). RESULTS: Elevated α-1,3 fucosylation was observed in cartilage from OA patients, rabbit models, and chondrocytes induced by TNF-α (fold change> 2, p< 0.01). Our results and the GEO database indicated that the overexpression of FUT10 contributed to this alteration. Silencing the expression of FUT10 impaired the ability of TNFR1 to bind to TNF-α, impeded activation of the NF-κB and P38/JNK-MAPK pathways, and eventually retarded extracellular matrix (ECM) degradation, senescence, and apoptosis in chondrocytes exposed to TNF-α. CONCLUSION: The elevation of α-1,3 fucosylation is not only a characteristic of OA but also impacts the OA pathological process. Our work provides a new positive feedback loop of "inflammation conditions/TNF-α/FUT10/α-1,3 fucosylation of TNFR1/NF-κB and P38/JNK-MAPK pathways/proinflammatory processes" that contributes to ECM degradation and chondrocyte apoptosis.

Role of salivary glycopatterns for oral microbiota associated with gastric cancer.

Microbiota in the oral cavity plays an important role in maintaining human health. Our previous studies have revealed significant alterations of salivary glycopatterns in gastric cancer (GC) patients, but it is unclear whether these altered salivary glycopatterns can cause the dysbiosis of oral microbiota. In this study, the oral microbiome of healthy volunteers (HVs) and GC patients were detected. The neoglycoproteins were then synthesized according to the altered glycopatterns in GC patients and used to explore the effects of specific salivary glycopattern against oral microbiota. The results showed that five species were significantly increased (p < 0.05) while two species were significantly decreased (p < 0.01) in the saliva of GC patients compared with that of HVs. And the fucose-neoglycoproteins (30-100 µg/mL) could reduce the adhesion and toxicity of Aggregatibacter segnis (A. segnis) to oral cells (HOEC and CAL-27), change the glycan structures of lipopolysaccharide on the surface of A. segnis, and enhance the capacity of A. segnis to trigger innate immune responses. This study revealed that the changes of salivary protein glycopatterns in GC patients might contribute to the dysbiosis of oral microbiota, and had important implications in developing new carbohydrate drugs to maintain a balanced microbiota in the oral.

Bioinformatics analysis reveals that ANXA1 and SPINK5 are novel tumor suppressor genes in patients with oral squamous cell carcinoma.

BACKGROUND: Oral squamous cell carcinoma (OSCC) is a solid tumor of squamous epithelial origin. Currently, surgery is still the main treatment for OSCC, with radiotherapy and chemotherapy as important adjuvant treatments. However, the problem of poor prognosis of OSCC patients still exists in clinical practice. To explore further potential biomarkers or treatment targets in OSCC patients, this study used a high-throughput gene expression database to study the potential molecular mechanisms of OSCC carcinogenesis. METHODS: The GEO database related to OSCC was searched and analyzed using GEO2R. Oncomine and the Human Protein Atlas were used to evaluate the expression level of differentially-expressed genes (DEGs). The cBioPortal dataset was used to analyze the mutations of the potential DEGs and patient survival. RESULTS: Three GEO datasets, GSE146483, GSE138206, and GSE148944, were downloaded and 7 DEGs were found in common in OSCC tissues. Using Oncomine and the Human Protein Atlas, ANXA1, IL1RN, and SPINK5 were decreased in cancer tissues, while protein levels of APOE and IFI35 were increased accordingly. Interestingly, low levels of ANXA1 and SPINKS were associated with the TNM stage of OSCC patients. No mutations in DEGs were found in OSCC patients, based on the cBioPortal dataset. Survival analysis indicated OSCC patients with high MSR1 had poor overall survival (OS), while low expression of CXCR4, ANXA1, IL1RN, and SPINK5 also predicted poor OS in OSCC patients. CONCLUSIONS: Our findings uncovered 7 potential biomarkers of OSCC patients, with ANXA1 and SPINK5 serving as potential tumor suppressor genes in OSCC.

Regulation of N6-Methyladenosine in the Differentiation of Cancer Stem Cells and Their Fate.

N6-methyladenosine (m6A) is one of the most common internal RNA modifications in eukaryotes. It is a dynamic and reversible process that requires an orchestrated participation of methyltransferase, demethylase, and methylated binding protein. m6A modification can affect RNA degradation, translation, and microRNA processing. m6A plays an important role in the regulation of various processes in living organisms. In addition to being involved in normal physiological processes such as sperm development, immunity, fat differentiation, cell development, and differentiation, it is also involved in tumor progression and stem cell differentiation. Curiously enough, cancer stem cells, a rare group of cells present in malignant tumors, retain the characteristics of stem cells and play an important role in the survival, proliferation, metastasis, and recurrence of cancers. Recently, studies demonstrated that m6A participates in the self-renewal and pluripotent regulation of these stem cells. However, considering that multiple targets of m6A are involved in different physiological processes, the exact role of m6A in cancer progression remains controversial. This article focuses on the mechanism of m6A and its effects on the differentiation of cancer stem cells, to provide a basis for elucidating the tumorigenesis mechanisms and exploring new potential therapeutic approaches.

The Tumor Suppressive Roles and Prognostic Values of STEAP Family Members in Breast Cancer.

OBJECTIVE: To investigate the expression patterns and prognostic values of STEAP family members in the occurrence and development of breast cancer. MATERIALS AND METHODS: The Human Protein Atlas was used to analyze the expression level of STEAPs in human normal tissues and malignant tumors. ONCOMINE datasets were analyzed for the comparison of the STEAPs levels between malignant cancers and corresponding normal tissues. Kaplan-Meier plotter was used to analyze the prognostic value of STEAPs in breast cancer patients. RESULTS: STEAPs were widely distributed in human normal tissues with diverse levels. Normally, it is predicted that STEAP1 and STEAP2 were involved in the mineral absorption process, while STEAP3 participated in the TP53 signaling pathway and iron apoptosis. The results from ONCOMINE showed downregulation of STEAP1, STEAP2, and STEAP4 in breast cancers. Survival analysis revealed that breast cancer patients with high levels of STEAP1, STEAP2, and STEAP4 had a good prognosis, while those with low expression had high overall mortality. CONCLUSION: STEAP1, STEAP2, and STEAP4 are predicted to be the potential prognostic biomarkers for breast cancer patients, providing novel therapeutic strategies for them.

Long non-coding RNAs engender drug resistance to different subtypes of treatments of breast cancers and may provide a "next generation" therapy option.

The dysfunction of long non-coding RNAs (lncRNAs), without protein-coding potential, has been implicated in drug resistance against treatment in various human diseases, especially in malignant tumors. As the most common-diagnosed female malignancy worldwide, breast cancer is also the second-leading cause of cancer-related mortality in women. Despite the improvement in neo-adjuvant therapy, endocrine therapy, molecular-targeted treatment, and chemotherapy, drug resistance to various treatment regimens is still quite prevalent. This article focused on the lncRNAs and their functions in drug resistance against breast cancer therapeutic agents, in order to develop new precise treatment strategies for patients with breast cancers. The discovery of lncRNA opened new doors to the molecular mechanisms of the biological processes, and has provided new pathways to regulate biochemical events. Thus, lncRNAs may be developed as a biomarker for the detection and/or prevention of breast cancer. Additionally, lncRNA-based approaches may provide an additional treatment modality in personalized medicine alone or in combination with existing tumor-directed interventions to improve patient outcomes. In conclusion, lncRNAs molecules may represent the "next generation" therapy option for breast cancer patients.

Integrated Glycome Strategy for Characterization of Aberrant LacNAc Contained N-Glycans Associated With Gastric Carcinoma.

Aberrant glycosylation is not only a feature of malignant cell transformation, but also plays an important role in metastasis. In the present study, an integrated strategy combining the lectin microarrays and lectin cytochemistry was employed to investigate and verify the altered glycopatterns in gastric cancer (GC) cell lines as well as resected tumor specimens from matched tissue sets of 46 GC patients. Subsequently, lectin-mediated affinity capture glycoproteins, and MALDI-TOF/TOF-MS were employed to further acquire precise structural information of the altered glycans. According to the results, the glycopatterns recognized by 10 (e.g., ACA, MAL-I, and ConA) and 3 lectins (PNA, MAL-I, and VVA) showed significantly variations in GC cells and tissue compared to their corresponding controls, respectively. Notably, the relative abundance of Galß-1,4GlcNAc (LacNAc) recognized by MAL-I exhibited a significant increase in GC cells (p < 0.001) and tissue from patients at stage II and III (p < 0.05), and a significant increase in lymph node positive tumor cases, compared with lymph node negative tumor cases (p < 0.05). More LacNAc contained N-glycans were characterized in tumor sample with advanced stage compared to corresponding control. Moreover, there were 10 neo-LacNAc-contained N-glycans (e.g., m/z 1625.605, 1803.652, and 1914.671) only presented in GC tissue with advanced stage. Among these, six N-glycans were modified with sialic acid or fucose based on LacNAc to form sialylated N-glycans or lewis antigens, respectively. Our results revealed that the aberrant expression of LacNAc is a characteristic of GC, and LacNAc may serve as a scaffold to be further modified with sialic acid or fucose. Our findings provided useful information for us to understand the development of GC.

Analysis of the Differentially Expressed Genes Induced by Cisplatin Resistance in Oral Squamous Cell Carcinomas and Their Interaction.

BACKGROUND: Oral squamous cell carcinoma (OSCC) is a solid tumor, which originates from squamous epithelium, with about 400,000 new-cases/year worldwidely. Presently, chemoradiotherapy is the most important adjuvant treatment for OSCC, mostly in advanced tumors. However, clinical resistance to chemotherapy still leads to poor prognosis of OSCC patients. Via high-throughput analysis of gene expression database of OSCC, we investigated the molecular mechanisms underlying cisplatin resistance in OSCC, analyzing the differentially expressed genes (DEGs) and their regulatory relationship, to clarify the molecular basis of OSCC chemotherapy resistance and provide a theoretical foundation for the treatment of patients with OSCC and individualized therapeutic targets accurately. METHODS: Datasets related to "OSCC" and "cisplatin resistance" (GSE111585 and GSE115119) were downloaded from the GEO database and analyzed by GEO2R. Venn diagram was used to obtain drug-resistance-related DEGs. Functional enrichment analysis and Kyoto encyclopedia of genes and genomes (KEGG) pathway analysis were performed on DEGs using The Database for Annotation, Visualization and Integrated Discovery (DAVID) software. Protein-protein interaction (PPI) network was constructed by STRING (search tool for recurring instances of neighbouring genes) database. Potential target genes of miRNA were predicted via miRDB, and cBioportal was used to analyze the function and survival of the potential functional genes. RESULTS: Forty-eight upregulated DEGs and 49 downregulated DEGs were obtained from the datasets, with cutoff as p < 0.01 and |log FC| > 1. The DEGs in OSCC mainly enriched in cell proliferation regulation, and chemokine activity. In PPI network with hub score > 300, the hub genes were identified as NOTCH1, JUN, CTNNB1, CEBPA, and ETS1. Among miRNA-mRNA targeting regulatory network, hsa-mir-200c-3p, hsa-mir-200b-3p, hsa-mir-429, and hsa-mir-139-5p were found to simultaneously regulate multiple hub genes. Survival analysis showed that patients with high CTNNB1 or low CEBPA expression had poor outcome. CONCLUSIONS: In the OSCC cisplatin-resistant cell lines, NOTCH1, JUN, CTNNB1, CEBPA, and ETS1 were found as the hub genes involved in regulating the cisplatin resistance of OSCC. Members of the miR-200 family may reverse drug resistance of OSCC cells by regulating the hub genes, which can act as potential targets for the treatment of OSCC patients with cisplatin resistance.

N-glycan profiles in H9N2 avian influenza viruses from chicken eggs and human embryonic lung fibroblast cells.

N-glycosylation can affect the host specificity, virulence and infectivity of influenza A viruses (IAVs). In this study, the distribution and evolution of N-glycosylation sites in the hemagglutinin (HA) and neuraminidase (NA) of H9N2 virus were explored using phylogenetic analysis. Then, one strain of the H9N2 subtypes was proliferated in the embryonated chicken eggs (ECE) and human embryonic lung fibroblast cells (MRC-5) system. The proliferated viral N-glycan profiles were analyzed by a glycomic method that combined the lectin microarray and MALDI-TOF/TOF-MS. As a result, HA and NA of H9N2 viruses prossess six and five highly conserved N-glycosylation sites, respectively. Sixteen lectins (e.g., MAL-II, SNA and UEA-I) had increased expression levels of the glycan structures in the MRC-5 compared with the ECE system; however, 6 lectins (e.g., PHA-E, PSA and DSA) had contrasting results. Eleven glycans from the ECE system and 13 glycans from the MRC-5 system were identified. Our results showed that the Fucα-1,6GlcNAc(core fucose) structure was increased, and pentaantennary N-glycans were only observed in the ECE system. The SAα2-3/6Gal structures were highly expressed and Fucα1-2Galß1-4GlcNAc structures were only observed in the MRC-5 system. We conclude that the existing SAα2-3/6Gal sialoglycans make the offspring of the H9N2 virus prefer entially attach to each other, which decreases the virulence. Alterations in the glycosylation sites for the evolution and role of IAVs have been widely described; however, little is known about the exact glycan structures for the same influenza strain from different hosts. Our findings may provide a novel way for further discussing the molecular mechanism of the viral transmission and virulence associated with viral glycosylation in avian and human hosts as well as vital information for designing a vaccine against influenza and other human viruses.