Explore the vast range of titles available.

Sialyl 6-sulfo Lewis X (6-sulfo sLeX) and its derivative sialyl 6-sulfo N-acetyllactosamine (LacNAc) are sialylated and sulfated glycans of sialomucins found in the high endothelial venules (HEVs) of secondary lymphoid organs. A component of 6-sulfo sLeX present in the core 1-extended O-linked glycans detected by the MECA-79 antibody was previously shown to exist in the lymphoid aggregate vasculature and bronchial mucosa of allergic and asthmatic lungs. The components of 6-sulfo sLeX in pulmonary tissues under physiological conditions remain to be analyzed. The CL40 antibody recognizes 6-sulfo sLeX and sialyl 6-sulfo LacNAc in O-linked and N-linked glycans, with absolute requirements for both GlcNAc-6-sulfation and sialylation. Immunostaining of normal mouse lungs with CL40 was performed and analyzed. The contribution of GlcNAc-6-O-sulfotransferases (GlcNAc6STs) to the synthesis of the CL40 epitope in the lungs was also elucidated. Here, we show that the expression of the CL40 epitope was specifically detected in the mesothelin-positive mesothelium of the pulmonary pleura. Moreover, GlcNAc6ST2 (encoded by Chst4) and GlcNAc6ST3 (encoded by Chst5), but not GlcNAc6ST1 (encoded by Chst2) or GlcNAc6ST4 (encoded by Chst7), are required for the synthesis of CL40-positive glycans in the lung mesothelium. Furthermore, neither GlcNAc6ST2 nor GlcNAc6ST3 is sufficient for in vivo expression of the CL40 epitope in the lung mesothelium, as demonstrated by GlcNAc6ST1/3/4 triple-knock-out and GlcNAc6ST1/2/4 triple-knock-out mice. These results indicate that CL40-positive sialylated and sulfated glycans are abundant in the pleural mesothelium and are synthesized complementarily by GlcNAc6ST2 and GlcNAc6ST3, under physiological conditions in mice.

Breast cancer tissue overexpresses fucosylated glycans, such as sialyl‐Lewis X/A (sLeX/A), and α‐1,3/4‐fucosyltransferases (FUTs) in relation to increased disease progression and metastasis. These glycans in tumor circulating cells mediate binding to vascular E‐selectin, initiating tumor extravasation. However, their role in breast carcinogenesis is still unknown. Here, we aimed to define the contribution of the fucosylated structures, including sLeX/A, to cell adhesion, cell signaling, and cell proliferation in invasive ductal carcinomas (IDC), the most frequent type of breast cancer. We first analyzed expression of E‐selectin ligands in IDC tissue and established primary cell cultures from the tissue. We observed strong reactivity with E‐selectin and anti‐sLeX/A antibodies in both IDC tissue and cell lines, and expression of α‐1,3/4 FUTs FUT4, FUT5, FUT6, FUT10, and FUT11. To further assess the role of fucosylation in IDC biology, we immortalized a primary IDC cell line with human telomerase reverse transcriptase to create the ‘CF1_T cell line’. Treatment with 2‐fluorofucose (2‐FF), a fucosylation inhibitor, completely abrogated its sLeX/A expression and dramatically reduced adherence of CF1_T cells to E‐selectin under hemodynamic flow conditions. In addition, 2‐FF‐treated CF1_T cells showed a reduced migratory ability, as well as decreased cell proliferation rate. Notably, 2‐FF treatment lowered the growth factor expression of CF1_T cells, prominently for FGF2, vascular endothelial growth factor, and transforming growth factor beta, and negatively affected activation of signal‐regulating protein kinases 1 and 2 and p38 mitogen‐activated protein kinase signaling pathways. These data indicate that fucosylation licenses several malignant features of IDC, such as cell adhesion, migration, proliferation, and growth factor expression, contributing to tumor progression. Breast invasive ductal carcinoma (IDC) overexpresses fucosylated glycans, such as sialyl‐Lewis X/A, which can be inhibited by 2‐fluorofucose (2‐FF). 2‐FF abrogates the capacity of IDC cells to bind to E‐selectin, reduces cell proliferation and cell migration, the expression of growth factor, and the activation of signal‐regulating protein kinases 1 and 2 ERK1/2 and p38 mitogen‐activated protein kinase signaling pathways. These data indicate that fucosylation inhibition prevents several malignant features of IDC.

In this study, a new water and alkaline‐soluble polysaccharide (ALP), with an average molecular weight of 6.63 × 104 Da, was successfully purified from the rhizomes of Atractylodes lancea. GC analysis demonstrated that ALP was a kind of glucan. The effect of the ALP on the interaction between E‐selectin and sialyl Lewis X (sLex) was examined in human osteosarcoma U‐2 OS cells. It was obvious that the expression of sLex antigen on the surface of U‐2 OS cells was visible under fluorescence microscopy. The addition of ALP (0.5, 1 and 2 mg/mL) resulted in a marked inhibition on the adhesion, migration and invasion of U‐2 OS cells to human umbilical vein endothelial cells (HUVECs), which was achieved by the decreased sLex expression on U‐2 OS cells. Additionally, the induction of apoptosis can be observed in U‐2 OS cells following ALP treatment using TUNEL staining and Annexin V‐FITC/PI double‐staining analysis on flow cytometry. In conclusion, these results indicated that ALP exerted anti‐metastatic activity towards osteosarcoma cells via inhibition of sLex/E‐selectin binding, which suggested that ALP could be a potent agent for human osteosarcoma intervention.

Mucin-type O -glycans are involved in cancer initiation and progression, although details of their biological and clinicopathological roles remain unclear. The aim of this study was to investigate the clinicopathological significance of β1,3- N -acetylglucosaminyltransferase 6 (β3Gn-T6), an essential enzyme for the synthesis of core 3 O -glycan and several other O -glycans in pancreatic ductal adenocarcinoma (PDAC). We performed immunohistochemical and lectin-histochemical analyses to detect the expression of β3Gn-T6 and several O -glycans in 156 cases of PDAC with pancreatic intraepithelial neoplasias (PanINs) and corresponding normal tissue samples. The T antigen, Tn antigen, sialyl Lewis X (sLeX) antigen, and sLeX on core 2 O -glycan were more highly expressed in PDAC cells than in normal pancreatic duct epithelial cells (NPDEs). Conversely, the expression of 6-sulfo N -acetyllactosamine on extended core 1 O -glycan was found in NPDEs and was low in PDAC cells. These glycan expression levels were not associated with patient outcomes. β3Gn-T6 was expressed in ~20% of PDAC cases and 30–40% of PanINs but not in NPDEs. Higher expression of β3Gn-T6 was found in PDAC cells in more differentiated adenocarcinoma cases showing significantly longer disease-free survival in both univariate and multivariate analyses. In addition, the expression of β3Gn-T6 in PDAC cells and PanINs significantly correlated with the expression of MUC5AC in these cells, suggesting that β3Gn-T6 expression is related to cellular differentiation status of the gastric foveolar phenotype. Thus, it is likely that β3Gn-T6 expression in PDAC cells is a favorable prognostic factor in PDAC patients, and that the expression of β3Gn-T6 correlates with the gastric foveolar phenotype in pancreatic carcinogenesis.

Successful embryo implantation requires a competent embryo, a receptive endometrium and synchronized communication between them. The selection of embryos with the highest implantation potential remains a challenge in the field of assisted reproductive technology. Moreover, little is known about the precise molecular mechanisms underlying embryo-endometrium crosstalk. MicroRNAs (miRNAs/miRs) have been detected in the spent embryo culture medium (SCM); however, their functions at the preimplantation stage remain unclear. In the present study, human SCM samples were collected during in vitro fertilization/intracytoplasmic sperm injection-embryo transfer and divided into implanted and not-implanted groups according to the clinical pregnancy outcomes. Total RNA was extracted and six miRNAs (miR-372-3p, miR-373-3p, miR-516b-5p, miR-517a-3p, miR-519d-3p and miR-520a-3p) were selected for reverse transcription-quantitative PCR (RT-qPCR) analysis. The results revealed that miR-372-3p and miR-519d-3p were markedly increased in SCM from blastocysts that failed to implant compared with in blastocysts that implanted. The receiver operating characteristic curve analysis revealed that miR-519d-3p was superior to miR-372-3p in predicting pregnancy outcomes. In vitro miRNA uptake and cell adhesion assays were performed to determine whether miR-519d-3p could be taken up by endometrial epithelial cells and to examine the biological roles of miR-519d-3p after internalization. Potential targets of miR-519d-3p were verified using a dual-luciferase reporter system. The results demonstrated that miR-519d-3p was taken up by human endometrial epithelial cells and that it may inhibit embryo adhesion by targeting HIF1α. Using RT-qPCR, western blot analysis and flow cytometry assay, HIF1α was shown to inhibit the biosynthesis of fucosyltransferase 7 and sialyl-Lewis X (sLex), a cell-surface oligosaccharide that serves an important role in embryonic apposition and adhesion. In addition, a mouse model was established and the results suggested that miR-519d-3p overexpression hampered embryo implantation in vivo. Taken together, miRNAs in SCM may serve as novel biomarkers for embryo quality. Furthermore, miR-519d-3p was shown to mediate embryo-endometrium crosstalk and to negatively regulate embryo implantation by targeting HIF1α/FUT7/sLex pathway.

Asthma is an allergic disease that causes severe infiltration of leukocytes into the lungs. Leukocyte infiltration is mediated by the binding of sialyl Lewis X (sLex) glycans present on the leukocytes to E-and P-selectins present on the endothelial cells at the sites of inflammation. Here, we found that mouse eosinophils express sLex glycans, and their infiltration into the lungs and proliferation in the bone marrow were significantly suppressed by an anti-sLex monoclonal antibody (mAb) F2 in a murine model of ovalbumin-induced asthma. The percentage of eosinophils in the bronchoalveolar lavage fluid and bone marrow and serum IgE levels decreased significantly in the F2-administered mice. Levels of T helper type 2 (Th2) cytokines and chemokines, involved in IgE class switching and eosinophil proliferation and recruitment, were also decreased in the F2-administered mice. An ex vivo cell rolling assay revealed that sLex glycans mediate the rolling of mouse eosinophils on P-selectin-expressing cells. These results indicate that the mAb F2 exerts therapeutic effects in a murine model of allergen-induced asthma, suggesting that sLex carbohydrate antigen could serve as a novel therapeutic target for allergic asthma.

Alterations in protein glycosylation are observed in many solid tumor types leading to formation of tumor-associated carbohydrate antigens (TACAs). The most common TACA is the Tn antigen (CD175), which is a mucin-type O -GalNAc-Ser/Thr/Tyr glycan in membrane and secreted glycoproteins. In addition, two other TACAs are CA19-9 (sialyl-Lewis a), which is used as a prognostic serum marker for pancreatic cancer, and its isomer sialyl-Lewis x (SLex, CD15s), which is overexpressed in many cancer types and associated with metastasis. While CD175 and other TACAs may be expressed by many human carcinomas, little is known about their differential expression patterns in tumors, thus limiting their use as tissue biomarkers or therapeutic targets. Here we address the clinicopathological relevance of the expression of CA19-9, CD15s, and CD175 in pancreatic ductal adenocarcinoma (PDAC) tissues. Semi-quantitative IHC staining with well-defined monoclonal antibodies demonstrates that CD175 is expressed in all PDAC specimens analyzed. Unexpectedly, however, these TACAs are differentially expressed within PDAC specimens and their glycoproteins, but not significantly expressed in adjacent normal tissues. These data provide avenues for novel therapeutic approaches that could combine CD175- and CA19-9-targeting therapies for PDAC patients.

Cell surface carbohydrate antigens sialyl Lewis X (sLeX) and Lewis Y (LeY) are paramount glycoconjugates and are abundantly expressed in the receptive endometrium. Furthermore, among the important biological functions of both antigens is their role in leukocytes adhesion and extravasation. Interleukin-1 beta (IL-1β) is involved in the process of human embryo implantation and placenta development. Here, we used an in vitro model to investigate whether sLeX and LeY are playing a role in the embryo implantation process mediated by IL-1β. Our results are showing that the expression of cell surface sLeX was enhanced in endometrial RL95-2 cells after exposure to IL-1β. RT-qPCR detection indicated that the transcript level of glycosyltransferase gene fucosyltransferase 3 (FUT3) was significantly elevated and that of FUT4/7 and ST3 beta-galactoside alpha-2,3-sialyltransferase 3/4 (ST3GAL3/4) were decreased by treatment with IL-1β. Modulatory role of glycosyltransferase FUT3 on sLeX biosynthesis was determined by FUT3 siRNA transfection in RL95-2 cells. Results showed that the expression level of sLeX was suppressed, but no change was observed in regard to LeY. Moreover, IL-1β promoted the HTR-8/SVneo trophoblast spheroids attachment to the RL95-2 endometrial monolayer, which was partially blocked by anti-sLeX antibody and FUT3 knockdown. Gene expression analysis of the RNA-seq transcriptome data from human secretory endometrium demonstrated a significantly higher level of FUT3 in the mid-secretory phase compared to the early secretory phase, which was correlated with the expression of IL1B. In summary, the inflammatory microenvironment at the fetomaternal interface can regulate the glycosylation pattern of endometrial cells at the time of implantation. SLeX can be significantly induced by IL-1β via increasing FUT3 expression, which facilitates the trophoblast adhesion during embryo implantation. Summary Sentence sLeX can be significantly induced by IL-1β via increasing FUT3 expression, which facilitates trophoblast adhesion during human embryo implantation. Graphical Abstract

PurposeEndometrial cancer (EC) is the most common gynecological cancer worldwide. Treatment has been improved in recent years, but, in advanced stages, therapeutical options are still limited. It has been reported that the expression of the blood group antigens Sialyl Lewis X (SLeX), Sialyl Lewis A (SLeA) and Lewis Y (LeY) is associated with prognosis in several tumors. Large studies on endometrial and cervical cancer are still pending.MethodsSpecimens of 234 patients with EC were immunohistochemically stained with antibodies for SLeX, SLeA and LeY. Expression was correlated to histopathological variables.ResultsHigh expression of SLeX was correlated to low pT-stage (p = 0.013), low grade (p < 0.001), low FIGO-stage (p = 0.006) and better overall survival rates (OS; p = 0.023). High expression of SLeA was associated with low pT-stage (p = 0.013), low grade (p = 0.001) and better progression-free survival (PFS; p = 0.043). LeY staining was correlated to pN + (p = 0.038), low grade (p = 0.005) and poorer PFS (p = 0.022).ConclusionThis is the first study examining the expression of SLeX, SLeA and LeY in EC, which can serve as additional future prognostic markers. Further studies are necessary to understand the underlying mechanisms. The study was approved by the local ethics committee of the Ludwig-Maximilians University Munich (reference number 19-249).

In the past decades, the roles of carbohydrates in living organisms and their potential use in many fields have been extensively investigated. Sialyl Lewis x (sLex), a member of body carbohydrate, is an inherent blood-type tetrasaccharide on the surface of different cells, the lymphocyte, neutrophil, some T cells, multiple tumor cells and so on. SLex is a common ligand of the three selectins, L-selectin, E-selectin and P-selectin, and plays important roles in multiple physiological phenomenas by interacting with selectins. Under normal physiological conditions, sLex can affect the immune process and fertilization process. Lower expression of sLex could cause leukocyte adhesion defects (LAD) II. Overexpression of sLex on the other hand has been linked to several cancers including melanoma, breast, pancreatic, liver, lung, head and neck, ovarian, bladder carcinomas and some blood disease including Hodgkin disease, some B cell chronic lymphocytic leukemias, acute lymphoblastic leukemias, and most acute nonlymphocytic leukemias. This paper mainly reviews the physiological functions and pathological effects of sLex and its applications in disease diagnosis, drug delivery, gene transfer and medical molecular imaging. We aim to help researchers and other readers quickly grasp the physiological and pathological roles and its medical applications of sLex, and give some suggestions for research directions.