Selectin ligands

Toward Ultrasound Molecular Imaging of Endothelial Dysfunction in Diabetes: Targets, Strategies, and Challenges

Diabetes vasculopathy is a significant complication of diabetes mellitus (DM), and early identification and timely intervention can effectively slow the progression. Accumulating studies have shown that diabetes causes vascular complications directly or indirectly through a variety of mechanisms. Direct imaging of the endothelial molecular changes not only identifies the early stage of diabetes vasculopathy but also sheds light on the precise treatment. Targeted ultrasound contrast agent (UCA)-based ultrasound molecular imaging (UMI) can noninvasively detect the expression status of molecular biomarkers overexpressed in the vasculature, thereby being a potential strategy for the diagnosis and treatment response evaluation of DM. Amounts of efforts have been focused on identification of the molecular targets expressed in the vasculature, manufacturing strategies of the targeted UCA, and the clinical translation for the diagnosis and evaluation of therapeutic efficacy in both micro- and macrovasculopathy in DM. This review summarizes the latest research progress on endothelium-targeted UCA and discusses their promising future and challenges in diabetes vasculopathy theranostics.

Sialyl LewisX glycomimetics bearing an extended anionic chain targeting E- and P- selectin binding sites

Neutrophil binding to vascular P- and E-selectin is the rate-limiting step in the recruitment of immune cells to sites of inflammation. Many diseases, including sickle cell anemia, post-myocardial infarction reperfusion injury, and acute respiratory distress syndrome are characterized by dysregulated inflammation. We have recently reported sialyl Lewisx analogues as potent antagonists of P- and E-selectin and demonstrated their in vivo immunosuppressive activity. A key component of these molecules is a tartrate diester that serves as an acyclic tether to orient the fucoside and the galactoside moiety in the required gauche conformation for optimal binding. The next stage of our study involved attaching an extended carbon chain onto one of the esters. This chain could be utilized to tether other pharmacophores, lipids, and contrast agents in the context of enhancing pharmacological applications through the sialyl Lewisx / receptor-mediated mechanism. Herein, we report our preliminary studies to generate a small library of tartrate based sialyl Lewisx analogues bearing extended carbon chains. Anionic charged chemical entities are attached to take advantage of proximal charged amino acids in the carbohydrate recognition domain of the selectin receptors. Starting with a common azido intermediate, synthesized using copper-catalyzed Huisgen 1,3-dipolar cycloadditions, these molecules demonstrate E- and P-selectin binding properties.

Dynamic Kinetic Stereoselective Glycosylation via RhII and Chiral Phosphoric Acid-Cocatalyzed Carbenoid Insertion to the Anomeric OH Bond for the Synthesis of Glycoconjugates

Chemical synthesis of glycoconjugates is essential for studying the biological functions of carbohydrates. We herein report an efficient approach for the stereoselective synthesis of challenging α-linked glycoconjugates via a RhII /chiral phosphoric acid (CPA)-cocatalyzed dynamic kinetic anomeric O-alkylation of sugar-derived lactols via carbenoid insertion to the anomeric OH bond. Notably, we observed excellent anomeric selectivity, excellent diastereoselectivity, broad substrate scope, and high efficiency for this glycosylation reaction by exploring various parameters of the cocatalytic system. DFT calculations suggested that the anomeric selectivity was mainly determined by steric interactions between the C2-carbon of the carbohydrate and the phenyl group of the metal carbenoid, while π/π interactions with the C2-OBn substituent on the carbohydrate substrate play a significant role for diastereoselectivity at the newly generated stereogenic center.

HAM/TSP Pathogenesis: The Transmigration Activity of HTLV-1-Infected T Cells into Tissues

Slowly progressive spastic paraparesis with bladder dysfunction, the main clinical feature of human T-cell leukemia virus-1 (HTLV-1)-associated myelopathy/tropical spastic paraparesis (HAM/TSP), is induced by chronic inflammation in the spinal cord, mainly the lower thoracic cord. A long-standing bystander mechanism, such as the destruction of surrounding tissues by inflammatory cytokines, etc., induced under the interaction between infiltrated HTLV-1-infected CD4⁺ T cells and HTLV-1-specific CD8⁺ cytotoxic T cells, has been considered implicated for the induction of chronic inflammation. As this bystander mechanism is triggered conceivably by the transmigration of HTLV-1-infected CD4⁺ T cells to the spinal cord, heightened transmigrating activity of HTLV-1-infected CD4⁺ T cells to the spinal cord might play a crucial role as the first responder in the development of HAM/TSP. This review evaluated the functions of HTLV-1-infected CD4⁺ T cells in HAM/TSP patients as the prerequisite for the acquisition of the activity such as adhesion molecule expression changes, small GTPases activation, and expression of mediators involved in basement membrane disruption. The findings suggest that HTLV-1-infected CD4⁺ T cells in HAM/TSP patients have enough potential to facilitate transmigration into the tissues. Future HAM/TSP research should clarify the molecular mechanisms leading to the establishment of HTLV-1-infected CD4⁺ T cells as the first responder in HAM/TSP patients. In addition, a regimen with an inhibitory activity against the transmigration of HTLV-1-infected CD4⁺ T cells into the spinal cord might be recommended as one of the therapeutic strategies against HAM/TSP patients.

Extracellular vesicles as central regulators of blood vessel function in cancer

Blood vessels deliver oxygen and nutrients that sustain tumor growth and enable the dissemination of cancer cells to distant sites and the recruitment of intratumoral immune cells. In addition, the structural and functional abnormalities of the tumor vasculature foster the development of an aggressive tumor microenvironment and impair the efficacy of existing cancer therapies. Extracellular vesicles (EVs) have emerged as major players of tumor progression, and a growing body of evidence has demonstrated that EVs derived from cancer cells trigger multiple responses in endothelial cells that alter blood vessel function in tumors. EV-mediated signaling in endothelial cells can occur through the transfer of functional cargos such as miRNAs, lncRNAs, cirRNAs, and proteins. Moreover, membrane-bound proteins in EVs can elicit receptor-mediated signaling in endothelial cells. Together, these mechanisms reprogram endothelial cells and contribute to the sustained exacerbated angiogenic signaling typical of tumors, which, in turn, influences cancer progression. Targeting these angiogenesis-promoting EV-dependent mechanisms may offer additional strategies to normalize tumor vasculature. Here, we discuss the current knowledge pertaining to the contribution of cancer cell-derived EVs in mechanisms regulating blood vessel functions in tumors. Moreover, we discuss the translational opportunities in targeting the dysfunctional tumor vasculature using EVs and highlight the open questions in the field of EV biology that can be addressed using mass spectrometry-based proteomics analysis.

P-selectin mobility undergoes a sol-gel transition as it diffuses from exocytosis sites into the cell membrane

In response to vascular damage, P-selectin molecules are secreted onto the surface of cells that line our blood vessels. They then serve as mechanical anchors to capture leucocytes from the blood stream. Here, we track individual P-selectin molecules released at the surface of live endothelial cells following stimulated secretion. We find P-selectin initially shows fast, unrestricted diffusion but within a few minutes, movement becomes increasingly restricted and ~50% of the molecules become completely immobile; a process similar to a sol-gel transition. We find removal of the extracellular C-type lectin domain (ΔCTLD) and/or intracellular cytoplasmic tail domain (ΔCT) has additive effects on diffusive motion while disruption of the adapter complex, AP2, or removal of cell-surface heparan sulphate restores mobility of full-length P-selectin close to that of ΔCT and ΔCTLD respectively. We have found P-selectin spreads rapidly from sites of exocytosis and evenly decorates the cell surface, but then becomes less mobile and better-suited to its mechanical anchoring function.

P-selectin recruits leucocytes to regions of blood vessel damage. Using single molecule imaging, we find newly secreted P-selectin spreads rapidly across the plasma membrane and then becomes immobilized and better-suited to leucocyte capture.

P- and E- selectin in venous thrombosis and non-venous pathologies

Venous thromboembolism is a very common and costly health problem worldwide. Anticoagulant treatment for VTE is imperfect: all have the potential for significant bleeding, and none prevent the development of post thrombotic syndrome after deep vein thrombosis or chronic thromboembolic pulmonary hypertension after pulmonary embolism. For these reasons, alternate forms of therapy with improved efficacy and decreased bleeding are needed. Selectins are a family (P-selectin, E-selectin, L-selectin) of glycoproteins that facilitate and augment thrombosis, modulating neutrophil, monocyte, and platelet activity. P- and E-selectin have been investigated as potential biomarkers for thrombosis. Inhibition of P-selectin and E-selectin decrease thrombosis and vein wall fibrosis, with no increase in bleeding. Selectin inhibition is a promising avenue of future study as either a stand-alone treatment for VTE or as an adjunct to standard anticoagulation therapies.

Fluid transport in the brain

The brain harbors a unique ability to, figuratively speaking, shift its gears. During wakefulness, the brain is geared fully toward processing information and behaving, while homeostatic functions predominate during sleep. The blood-brain barrier establishes a stable environment that is optimal for neuronal function, yet the barrier imposes a physiological problem; transcapillary filtration that forms extracellular fluid in other organs is reduced to a minimum in brain. Consequently, the brain depends on a special fluid [the cerebrospinal fluid (CSF)] that is flushed into brain along the unique perivascular spaces created by astrocytic vascular endfeet. We describe this pathway, coined the term glymphatic system, based on its dependency on astrocytic vascular endfeet and their adluminal expression of aquaporin-4 water channels facing toward CSF-filled perivascular spaces. Glymphatic clearance of potentially harmful metabolic or protein waste products, such as amyloid-β, is primarily active during sleep, when its physiological drivers, the cardiac cycle, respiration, and slow vasomotion, together efficiently propel CSF inflow along periarterial spaces. The brain's extracellular space contains an abundance of proteoglycans and hyaluronan, which provide a low-resistance hydraulic conduit that rapidly can expand and shrink during the sleep-wake cycle. We describe this unique fluid system of the brain, which meets the brain's requisites to maintain homeostasis similar to peripheral organs, considering the blood-brain-barrier and the paths for formation and egress of the CSF.

Deoxy sugars. General methods for carbohydrate deoxygenation and glycosidation

Deoxy sugars represent an important class of carbohydrates, present in a large number of biomolecules involved in multiple biological processes. In various antibiotics, antimicrobials, and therapeutic agents the presence of deoxygenated units has been recognized as responsible for biological roles, such as adhesion or great affinity to receptors, or improved efficacy. The characterization of glycosidases and glycosyltranferases requires substrates, inhibitors and analogous compounds. Deoxygenated sugars are useful for carrying out specific studies for these enzymes. Deoxy sugars, analogs of natural substrates, may behave as substrates or inhibitors, or may not interact with the enzyme. They are also important for glycodiversification studies of bioactive natural products and glycobiological processes, which could contribute to discovering new therapeutic agents with greater efficacy by modification or replacement of sugar units. Deoxygenation of carbohydrates is, thus, of great interest and numerous efforts have been dedicated to the development of methods for the reduction of sugar hydroxyl groups. Given that carbohydrates are the most important renewable chemicals and are more oxidized than fossil raw materials, it is also important to have methods to selectively remove oxygen from certain atoms of these renewable raw materials. The different methods for removal of OH groups of carbohydrates and representative or recent applications of them are presented in this chapter. Glycosidic bonds in general, and 2-deoxy glycosidic linkages, are included. It is not the scope of this survey to cover all reports for each specific technique.

A QCM study of strong carbohydrate-carbohydrate interactions of glycopolymers carrying mannosides on substrates

Carbohydrates on cell surfaces are known to interact not only with lectins but also with other carbohydrates; the latter process is known as a carbohydrate-carbohydrate interaction. Such interactions are observed in complex oligosaccharides. It would be surprising if these interactions were observed in simple monosaccharides of mannose. In this study, the interaction between glycopolymers carrying monosaccharides of mannose was quantitatively investigated by quartz crystal microbalance measurements. We measured the interactions with glycopolymers carrying mannose, galactose and glucose. Surprisingly, the interaction between the glycopolymers and mannose was much stronger than that between other saccharides.

Adhesion Molecules Involved in Stem Cell Niche Retention During Normal Haematopoiesis and in Acute Myeloid Leukaemia

In the bone marrow (BM) of adult mammals, haematopoietic stem cells (HSCs) are retained in micro-anatomical structures by adhesion molecules that regulate HSC quiescence, proliferation and commitment. During decades, researchers have used engraftment to study the function of adhesion molecules in HSC's homeostasis regulation. Since the 90's, progress in genetically engineered mouse models has allowed a better understanding of adhesion molecules involved in HSCs regulation by BM niches and raised questions about the role of adhesion mechanisms in conferring drug resistance to cancer cells nested in the BM. This has been especially studied in acute myeloid leukaemia (AML) which was the first disease in which the concept of cancer stem cell (CSC) or leukemic stem cells (LSCs) was demonstrated. In AML, it has been proposed that LSCs propagate the disease and are able to replenish the leukemic bulk after complete remission suggesting that LSC may be endowed with drug resistance properties. However, whether such properties are due to extrinsic or intrinsic molecular mechanisms, fully or partially supported by molecular crosstalk between LSCs and surrounding BM micro-environment is still matter of debate. In this review, we focus on adhesion molecules that have been involved in HSCs or LSCs anchoring to BM niches and discuss if inhibition of such mechanism may represent new therapeutic avenues to eradicate LSCs.

Engineering the Sialome

The surface of every eukaryotic cell is coated in a dense layer of structurally diverse glycans that together comprise the glycocalyx, a key interface between intracellular biochemistry and the external environment. Many of the glycans within the glycocalyx terminate in anionic monosaccharides belonging to the sialic acid family. Advances in our understanding of the biological processes mediated by sialic acids at the interfaces between cells have catalyzed interest in metabolic, enzymatic, and chemical strategies to edit the total complement of cellular sialic acids-the sialome. Here, we review strategies for altering the composition of the sialome with particular focus on glycan structures and state-of-the-art tools.

Dual targeting single arrow: Neutrophil-targeted sialic acid-modified nanoplatform for treating comorbid tumors and rheumatoid arthritis

Clinically, rheumatoid arthritis (RA) is frequently accompanied by multi-system diseases. Among them, the incidence of comorbid tumors in RA is relatively high, resulting in a gradual increase in mortality; this poses a considerable challenge to clinical treatment. To date, no effective treatment plan for simultaneous tumor and RA therapy is available. Accordingly, we reported a sialic acid-modified doxorubicin hydrochloride liposome (DOX-SAL) that targets peripheral blood neutrophils (PBNs), which play an important role in tumors and RA. Furthermore, the prepared liposome induced PBN apoptosis by binding to L-selectin, which is highly expressed on the surface of PBNs activated by inflammation. This liposome, in turn, reduced the accumulation of inflammatory neutrophils at the disease site. In the first successfully established mouse model of RA comorbidity, induced by employing S180 sarcoma cells and collagen, DOX-SAL effectively inhibited tumor growth while simultaneously alleviating systemic RA symptoms without side effects. Additionally, the animals demonstrated adequate growth during the 48 days of treatment. This treatment strategy encompasses the best of both worlds, breaking the deadlock that tumors and RA cannot be effectively treated in parallel, highlighting a new concept and reference for the clinical treatment of comorbid tumors and RA.

What is the Sugar Code?

A code is defined by the nature of the symbols, which are used to generate information‐storing combinations (e. g. oligo‐ and polymers). Like nucleic acids and proteins, oligo‐ and polysaccharides are ubiquitous, and they are a biochemical platform for establishing molecular messages. Of note, the letters of the sugar code system (third alphabet of life) excel in coding capacity by making an unsurpassed versatility for isomer (code word) formation possible by variability in anomery and linkage position of the glycosidic bond, ring size and branching. The enzymatic machinery for glycan biosynthesis (writers) realizes this enormous potential for building a large vocabulary. It includes possibilities for dynamic editing/erasing as known from nucleic acids and proteins. Matching the glycome diversity, a large panel of sugar receptors (lectins) has developed based on more than a dozen folds. Lectins ‘read’ the glycan‐encoded information. Hydrogen/coordination bonding and ionic pairing together with stacking and C−H/π‐interactions as well as modes of spatial glycan presentation underlie the selectivity and specificity of glycan‐lectin recognition. Modular design of lectins together with glycan display and the nature of the cognate glycoconjugate account for the large number of post‐binding events. They give an entry to the glycan vocabulary its functional, often context‐dependent meaning(s), hereby building the dictionary of the sugar code.

Neutrophil azurophilic granule glycoproteins are distinctively decorated by atypical pauci- and phosphomannose glycans

While neutrophils are critical first-responders of the immune system, they also cause tissue damage and act in a variety of autoimmune diseases. Many neutrophil proteins are N-glycosylated, a post-translational modification that may affect, among others, enzymatic activity, receptor interaction, and protein backbone accessibility. So far, a handful neutrophil proteins were reported to be decorated with atypical small glycans (paucimannose and smaller) and phosphomannosylated glycans. To elucidate the occurrence of these atypical glycoforms across the neutrophil proteome, we performed LC-MS/MS-based (glyco)proteomics of pooled neutrophils from healthy donors, obtaining site-specific N-glycan characterisation of >200 glycoproteins. We found that glycoproteins that are typically membrane-bound to be mostly decorated with high-mannose/complex N-glycans, while secreted proteins mainly harboured complex N-glycans. In contrast, proteins inferred to originate from azurophilic granules carried distinct and abundant paucimannosylation, asymmetric/hybrid glycans, and glycan phosphomannosylation. As these same proteins are often autoantigenic, uncovering their atypical glycosylation characteristics is an important step towards understanding autoimmune disease and improving treatment.

Display of the human mucinome with defined O-glycans by gene engineered cells

Mucins are a large family of heavily O-glycosylated proteins that cover all mucosal surfaces and constitute the major macromolecules in most body fluids. Mucins are primarily defined by their variable tandem repeat (TR) domains that are densely decorated with different O-glycan structures in distinct patterns, and these arguably convey much of the informational content of mucins. Here, we develop a cell-based platform for the display and production of human TR O-glycodomains (~200 amino acids) with tunable structures and patterns of O-glycans using membrane-bound and secreted reporters expressed in glycoengineered HEK293 cells. Availability of defined mucin TR O-glycodomains advances experimental studies into the versatile role of mucins at the interface with pathogenic microorganisms and the microbiome, and sparks new strategies for molecular dissection of specific roles of adhesins, glycoside hydrolases, glycopeptidases, viruses and other interactions with mucin TRs as highlighted by examples.

B cell depletion inhibits fibrosis via suppressing pro-fibrotic macrophage differentiation in a mouse model of systemic sclerosis

OBJECTIVE

We investigated the effect of B cell depletion on fibrosis in systemic sclerosis (SSc) and its mechanism of action.

METHODS

Bleomycin-induced SSc (BLM-SSc) model mice were treated with anti-CD20 antibody, and skin and lung fibrosis was evaluated histopathologically. T cells and macrophages were co-cultured with B cells, and the effect of B cells on their differentiation was assessed by flow cytometry. We also co-cultured B cells and monocytes from SSc patients and analyzed the correlation between fibrosis and pro-fibrotic macrophage induction by B cells.

RESULTS

B cell depletion inhibited fibrosis in BLM-SSc mice. B cells from BLM-SSc mice increased pro-inflammatory cytokine producing T cells in co-culture. In BLM-SSc mice, B cell depletion before BLM treatment (pre-depletion) inhibited fibrosis more strongly than B cell depletion after BLM treatment (post-depletion). However, the frequencies of pro-inflammatory T cells were lower in the post-depletion group than in the pre-depletion group. This discrepancy suggests that the effect of B cell depletion on fibrosis cannot be explained by its effect on T cell differentiation. On the other hand, pro-fibrotic macrophages were markedly decreased in the pre-depletion group than in the post-depletion group. Furthermore, B cells from BLM-SSc mice increased pro-fibrotic macrophage differentiation in co-culture. In SSc patients, the extent of pro-fibrotic macrophage induction by B cells correlated with the severity of fibrosis.

CONCLUSION

These findings suggest that B cell depletion inhibits tissue fibrosis via suppressing pro-fibrotic macrophage differentiation in BLM-SSc mice, providing a new rationale for B cell depletion therapy in SSc.

Probing the binding specificities of human Siglecs by cell-based glycan arrays

Siglecs are a family of sialic acid-binding receptors expressed by cells of the immune system and a few other cell types capable of modulating immune cell functions upon recognition of sialoglycan ligands. While human Siglecs primarily bind to sialic acid residues on diverse types of glycoproteins and glycolipids that constitute the sialome, their fine binding specificities for elaborated complex glycan structures and the contribution of the glycoconjugate and protein context for recognition of sialoglycans at the cell surface are not fully elucidated. Here, we generated a library of isogenic human HEK293 cells with combinatorial loss/gain of individual sialyltransferase genes and the introduction of sulfotransferases for display of the human sialome and to dissect Siglec interactions in the natural context of glycoconjugates at the cell surface. We found that Siglec-4/7/15 all have distinct binding preferences for sialylated GalNAc-type O-glycans but exhibit selectivity for patterns of O-glycans as presented on distinct protein sequences. We discovered that the sulfotransferase CHST1 drives sialoglycan binding of Siglec-3/8/7/15 and that sulfation can impact the preferences for binding to O-glycan patterns. In particular, the branched Neu5Acα2-3(6-O-sulfo)Galβ1-4GlcNAc (6'-Su-SLacNAc) epitope was discovered as the binding epitope for Siglec-3 (CD33) implicated in late-onset Alzheimer's disease. The cell-based display of the human sialome provides a versatile discovery platform that enables dissection of the genetic and biosynthetic basis for the Siglec glycan interactome and other sialic acid-binding proteins.

Early prediction of putamen imaging features in HIV-associated neurocognitive impairment syndrome

Background

To explore the correlation between the volume of putamen and brain cognitive impairment in patients with HIV and to predict the feasibility of early-stage HIV brain cognitive impairment through radiomics.

Method

Retrospective selection of 90 patients with HIV infection, including 36 asymptomatic neurocognitive impairment (ANI) patients and 54 pre-clinical ANI patients in Beijing YouAn Hospital. All patients received comprehensive neuropsychological assessment and MRI scanning. 3D Slicer software was used to acquire volume of interest (VOI) and radiomics features. Clinical variables and volume of putamen were compared between patients with ANI and pre-clinical ANI. The Kruskal Wallis test was used to analysis multiple comparisons between groups. The relationship between cognitive scores and VOI was compared using linear regression. For radiomics, principal component analysis (PCA) was used to reduce model overfitting and calculations and then a support vector machine (SVM) was used to build a binary classification model. For model performance evaluation, we used an accuracy, sensitivity, specificity and receiver operating characteristic curve (ROC).

Result

There were no significant differences in clinical variables between ANI group and pre-clinical-ANI group (P>0.05). The volume of bilateral putamen was significantly different between AHI group and pre-clinical group (P<0.05), but there was only a trend in the left putamen between ANI-treatment group and pre-clinical treatment group(P = 0.063). Reduced cognitive scores in Verbal Fluency, Attention/Working Memory, Executive Functioning, memory and Speed of Information Processing were negatively correlated with the increased VOI (P<0.05), but the correlation was relatively low. In diagnosing the ANI from pre-clinical ANI, the mean area under the ROC curves (AUC) were 0.85 ± 0.22, the mean sensitivity and specificity were 63.12 ± 5.51 and 94.25% ± 3.08%.

Conclusion

The volumes of putamen in patients with ANI may be larger than patients with pre-clinical ANI, the change of the volume of the putamen may have a certain process; there is a relationship between putamen and cognitive impairment, but the exact mechanism is unclear. Radiomics may be a useful tool for predicting early stage HAND in patients with HIV.

Genetic glycoengineering in mammalian cells

Advances in nuclease-based gene-editing technologies have enabled precise, stable, and systematic genetic engineering of glycosylation capacities in mammalian cells, opening up a plethora of opportunities for studying the glycome and exploiting glycans in biomedicine. Glycoengineering using chemical, enzymatic, and genetic approaches has a long history, and precise gene editing provides a nearly unlimited playground for stable engineering of glycosylation in mammalian cells to explore and dissect the glycome and its many biological functions. Genetic engineering of glycosylation in cells also brings studies of the glycome to the single cell level and opens up wider use and integration of data in traditional omics workflows in cell biology. The last few years have seen new applications of glycoengineering in mammalian cells with perspectives for wider use in basic and applied glycosciences, and these have already led to discoveries of functions of glycans and improved designs of glycoprotein therapeutics. Here, we review the current state of the art of genetic glycoengineering in mammalian cells and highlight emerging opportunities.

A Three-Dimensional Microfluidic Device for Monitoring Cancer and Chemotherapy-Associated Platelet Activation

Platelet activation and the risk of thrombosis are increased in cancer patients, especially after chemotherapy. Our previous studies indicated that chemotherapy-induced platelet activation is largely due to endothelial cell damage. Thus, simple in vitro tests, such as aggregometry, are not desirable tests to predict platelet responsiveness to different chemotherapeutic agents because other contributory factors, such as tumor cells, endothelial cells, and the flow rate of platelets, also contribute to the formation of cancer-associated thrombosis. Therefore, developing a platelet detection system, which includes all possible risk parameters, is necessary. In the present study, we described a microengineered microfluidic system that contained a drug concentration generator, cancer cell culture chip, and three-dimensional (3D) circular microvascular model covered with a confluent endothelial layer and perfused with human platelets at a stable flow rate. Doxorubicin was injected through two injection sites. Endothelial cell injury was evaluated by counting, cell cytoskeleton observation, and the level of IACM1 and ET-1 in endothelial cells or a culture medium. Prestained platelets were perfused into the artificial blood vessel, and platelet-endothelial cell adhesion was measured. We found that (i) MCF7 cell-released factors had a cytotoxicity effect on both endothelial cells and platelets. (ii) We confirmed that doxorubicin-induced platelet activation was endothelial cell-dependent. (iii) A lower dosage of doxorubicin (0-2.0 μM) induced platelet activation, while a higher dosage of doxorubicin (2.0-4.0 μM) led to platelet death. Our findings indicated that platelet-endothelial cell adhesion could be used as a diagnostic marker of platelet activation, providing a simple and rapid detective way to predict platelet responsiveness before or during chemotherapy.

Von Willebrand factor:antigen and ADAMTS-13 level, but not soluble P-selectin, are risk factors for the first asymptomatic deep vein thrombosis in cancer patients undergoing chemotherapy

Background

There is a high incidence of deep vein thrombosis (DVT) among cancer patients undergoing chemotherapy. Chemotherapy-induced vascular endothelial cell activation (VECA) is characterized by increased plasma levels of von Willebrand factor (vWF) and soluble P-selectin (sP-selectin), leading to the activation of endothelial cells and signaling cascades. The biological role of a disintegrin-like and metalloproteinase with thrombospondin type 1 motif, member 13 (ADAMTS-13) is to control the activity of vWF and consequently the risk of thrombosis. The objective of this study was to investigate the roles of sP-selectin, vWF, and ADAMTS-13 as risk factors for the first episode of DVT in cancer patients undergoing chemotherapy.

Methods

This prospective cohort study was conducted at Dr. Kariadi Hospital, Indonesia, on 40 cancer patients. Prechemotherapy (baseline) and postchemotherapy sP-selectin, vWF antigen (vWF:Ag), and ADAMTS-13 plasma levels were determined with ELISAs before and 3 months after chemotherapy. The clinical characteristics of the patients, cancer type, cancer stage, chemotherapy regimen, ABO blood type, D-dimer level and Khorana risk score were also analyzed using logistic regression. Patients were observed for the possibility of developing DVT during chemotherapy.

Results

DVT was confirmed in 5 patients (12.5%) after a period of 3 months. In patients with DVT, sP-selectin and vWF were significantly higher while ADAMTS-13 was lower than in their counterparts. The levels of baseline vWF:Ag and ADAMTS-13, with cut-off points ≥ 2.35 IU/mL and ≤ 1.03 IU/mL, respectively, were found to independently predict the incidence of DVT. In the multivariate logistic regression analysis, the relative risk (RR) for DVT in patients with high vWF:Ag was 3.80 (95% CI 1.15–12.48, p = 0.028), and that for patients with low ADAMTS-13 was 2.67 (95% CI 1.22–23.82, p = 0.005). The vWF:Ag/ADAMTS-13 ratio and both vWF:Ag and ADAMTS-13 dynamics during treatment were also able to differentiate those with prospective DVT. However, sP-selectin and other covariates showed no statistical significance.

Conclusion

We found that prechemotherapy plasma levels of vWF:Ag ≥ 2.35 IU/mL and ADAMTS-13 ≤ 1.03 IU/mL are independent risk factors for DVT incidence among cancer patients.

A Atractylodes lancea polysaccharide inhibits metastasis of human osteosarcoma U-2 OS cells by blocking sialyl Lewis X (sLex )/E-selectin binding

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 (sLe^x) was examined in human osteosarcoma U‐2 OS cells. It was obvious that the expression of sLe^x 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 sLe^x 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 sLe^x/E‐selectin binding, which suggested that ALP could be a potent agent for human osteosarcoma intervention.

Selectins: An Important Family of Glycan-Binding Cell Adhesion Molecules in Ovarian Cancer

Ovarian cancer is the most lethal gynecological malignancy worldwide. Unlike most other tumor types that metastasize via the vasculature, ovarian cancer metastasizes predominantly via the transcoelomic route within the peritoneal cavity. As cancer metastasis accounts for the majority of deaths, there is an urge to better understand its determinants. In the peritoneal cavity, tumor-mesothelial adhesion is an important step for cancer dissemination. Selectins are glycan-binding molecules that facilitate early steps of this adhesion cascade by mediating heterotypic cell-cell interaction under hydrodynamic flow. Here, we review the function and regulation of selectins in peritoneal carcinomatosis of ovarian cancer, and highlight how dysregulation of selectin ligand biogenesis affects disease outcome. Further, we will introduce the latest tools in studying selectin-glycan interaction. Finally, an overview of potential therapeutic intervention points that may lead to the development of efficacious therapies for ovarian cancer is provided.

Mucins and the Microbiome

Generating the barriers that protect our inner surfaces from bacteria and other challenges requires large glycoproteins called mucins. These come in two types, gel-forming and transmembrane, all characterized by large, highly O-glycosylated mucin domains that are diversely decorated by Golgi glycosyltransferases to become extended rodlike structures. The general functions of mucins on internal epithelial surfaces are to wash away microorganisms and, even more importantly, to build protective barriers. The latter function is most evident in the large intestine, where the inner mucus layer separates the numerous commensal bacteria from the epithelial cells. The host's conversion of MUC2 to the outer mucus layer allows bacteria to degrade the mucin glycans and recover the energy content that is then shared with the host. The molecular nature of the mucins is complex, and how they construct the extracellular complex glycocalyx and mucus is poorly understood and a future biochemical challenge.

Photoactivation of sulfonated polyplexes enables localized gene silencing by DsiRNA in breast cancer cells

Translation potential of RNA interference nanotherapeutics remains challenging due to in vivo off-target effects and poor endosomal escape. Here, we developed novel polyplexes for controlled intracellular delivery of dicer substrate siRNA, using a light activation approach. Sulfonated polyethylenimines covalently linked to pyropheophorbide-α for photoactivation and bearing modified amines (sulfo-pyro-PEI) for regulated endosomal escape were investigated. Gene knock-down by the polymer-complexed DsiRNA duplexes (siRNA-NPs) was monitored in breast cancer cells. Surprisingly, sulfo-pyro-PEI/siRNA-NPs failed to downregulate the PLK1 or eGFP proteins. However, photoactivation of these cell associated-polyplexes with a 661-nm laser clearly restored knock-down of both proteins. In contrast, protein down-regulation by non-sulfonated pyro-PEI/siRNA-NPs occurred without any laser treatments, indicating cytoplasmic disposition of DsiRNA followed a common intracellular release mechanism. Therefore, sulfonated pyro-PEI holds potential as a unique trap and release light-controlled delivery platform for on-demand gene silencing bearing minimal off target effects.

Sialic acid-conjugate modified liposomes targeting neutrophils for improved tumour therapy

Neutrophils are the most abundant white blood cells in humans. Many tumor-treatment methods that are related to tissue infiltration and the activation of neutrophils have been developed. In particular, one strategy, which aims to improve tumor treatment, involves the exploitation or targeting of activated neutrophils. Peripheral blood neutrophils (PBNs) from tumor-bearing mice display high expression of l-selectin, which is well known to be targeted by the sialic acid (SA) ligand. Hence, in this research, we developed a drug delivery platform involving liposomes modified with an SA conjugate that targets activated PBNs. The uptake of doxorubicin (DOX)-loaded liposomes by PBNs did not alter their activation and transmigration. Furthermore, in tumor-bearing mice, SA-modified liposomes displayed a greater tumor-targeting ability and stronger tumor treatment efficacy, which were mediated by the neutrophil infiltration induced by inflammatory factors released from the tumor microenvironment. In conclusion, SA-modified liposomal DOX was shown to be an effective neutrophil-mediated drug delivery system for tumor therapy.

CDG and immune response: From bedside to bench and back

Glycosylation is an essential biological process that adds structural and functional diversity to cells and molecules, participating in physiological processes such as immunity. The immune response is driven and modulated by protein-attached glycans that mediate cell-cell interactions, pathogen recognition and cell activation. Therefore, abnormal glycosylation can be associated with deranged immune responses. Within human diseases presenting immunological defects are congenital disorders of glycosylation (CDG), a family of around 130 rare and complex genetic diseases. In this review, we have identified 23 CDG with immunological involvement, characterized by an increased propensity to-often life-threatening-infection. Inflammatory and autoimmune complications were found in 7 CDG types. CDG natural history(ies) and the mechanisms behind the immunological anomalies are still poorly understood. However, in some cases, alterations in pathogen recognition and intracellular signaling (eg, TGF-β1, NFAT, and NF-κB) have been suggested. Targeted therapies to restore immune defects are only available for PGM3-CDG and SLC35C1-CDG. Fostering research on glycoimmunology may elucidate the involved pathophysiological mechanisms and open new therapeutic avenues, thus improving CDG patients' quality of life.

Pharmaceutical Development and Safety Evaluation of a GMP-Grade Fucoidan for Molecular Diagnosis of Cardiovascular Diseases

The adhesion molecule P-selectin is present on the cell surface of both activated endothelium and activated platelets. The present study describes the pharmaceutical development, safety evaluation, and preclinical efficacy of a micro-dosed radiotracer. The macromolecular nanoscale assembly consisted of a natural compound made of a sulfated fucose-rich polysaccharides (fucoidan) and a radionuclide (technetium-99m) for the detection of P-selectin expression in cardiovascular diseases. After extraction and fractionation from brown seaweeds, the good manufacturing practice (GMP) production of a low molecular weight (LMW) fucoidan of 7 kDa was achieved and full physicochemical characterization was performed. The regulatory toxicology study in rats of the GMP batch of LMW fucoidan revealed no adverse effects up to 400 μg/kg (×500 higher than the expected human dose) and pseudoallergy was not seen as well. In a myocardial ischemia-reperfusion model in rats, the GMP-grade LMW fucoidan labeled with technetium-99m detected P-selectin upregulation in vivo. The present study supports the potential of using ^99mTc-fucoidan as an imaging agent to detect activated endothelium in humans.

Neuraminidase-3 Is a Negative Regulator of LFA-1 Adhesion

Within the plasma membrane environment, glycoconjugate-receptor interactions play an important role in the regulation of cell-cell interactions. We have investigated the mechanism and activity of the human neuraminidase (NEU) isoenzyme, NEU3, on T cell adhesion receptors. The enzyme is known to prefer glycolipid substrates, and we confirmed that exogenous enzyme altered the glycolipid composition of cells. NEU3 was able to modify the sialic acid content of purified LFA-1 in vitro. Enzymatic activity of NEU3 resulted in re-organization of LFA-1 into large clusters on the membrane. This change was facilitated by an increase in the lateral mobility of LFA-1 upon NEU3 treatment. Changes to the lateral mobility of LFA-1 were specific for NEU3 activity, and we observed no significant change in diffusion when cells were treated with a bacterial NEU (NanI). Furthermore, we found that NEU3 treatment of cells increased surface expression levels of LFA-1. We observed that NEU3-treated cells had suppressed LFA-1 adhesion to an ICAM-1 coated surface using an in vitro static adhesion assay. These results establish that NEU3 can modulate glycoconjugate composition and contribute to the regulation of integrin activity. We propose that NEU3 should be investigated to determine its role on LFA-1 within the inflammatory cascade.

Fucoidan from sea cucumber Holothuria polii: Structural elucidation and stimulation of hematopoietic activity

The structural elucidation of polysaccharides is essential for understanding their structure-bioactivity relationship and related drug development. In this study, fucoidan (Fuc_hp) was extracted and purified from sea cucumber Holothuria polii. Its sulfate content was 39.5 ± 1.4%, and the "weight-average" molecular mass was 103.1 ± 2.8 kDa. The primary structure of Fuc_hp was clarified using a combination of acid degradation, tandem mass spectrometry, and nuclear magnetic resonance spectroscopy analysis. As a result, Fuc_hp was found to be composed of a tetrafucose repeating unit [→3-α-l-Fucp-1 → 3-α-l-Fucp2(OSO₃^-)-1 → 3-α-l-Fucp2(OSO₃^-)-1 → 3-α-l-Fucp2,4(OSO₃^-)-1→]. The stimulating hematopoiesis was further evaluated in a mouse model induced by cyclophosphamide. Based on these findings, intraperitoneally administered Fuc_hp may accelerate the recovery of white blood cells and neutrophils, in which its activity exceeded that of recombinant human granulocyte colony-stimulating factor (rhG-CSF). Meanwhile, in the background of cyclophosphamide-induced immunosuppression, treatment with Fuc_hp reduces platelet aggregation caused by CTX, so it might have the effect of reducing the risk of thrombosis. Therefore, Fuc_hp can be exploited as potentially promising stimulator of hematopoiesis in the future.

Carcinoembryonic antigen carrying SLeX as a new biomarker of more aggressive gastric carcinomas

Malignant transformation of gastric cells is accompanied by the deregulated expression of glycosyltransferases leading to the biosynthesis of tumor-associated glycans such as the sialyl-Lewis X antigen (SLe^x). SLe^x presence on cell surface glycoconjugates increases the invasive capacity of gastric cancer cells and is associated with tumor metastasis. ST3Gal IV enzyme is involved in the synthesis of SLe^x antigen and overexpressed in gastric carcinomas. Herein, we identified the glycoproteins carrying SLe^x in gastric cancer cells overexpressing ST3Gal IV enzyme and evaluated their biomarker potential for gastric carcinoma.

Methods: SLe^x modified glycoproteins were identified applying western blot and mass spectrometry. Immunoprecipitation, proximity ligation assay (PLA), E-selectin binding assay and CRISPR/cas9 knockout experiments were performed to characterize the presence of SLe^x on the identified glycoprotein. Protein N-glycans of the SLe^x protein carrier were in deep analyzed by porous-graphitized-carbon liquid-chromatography and tandem mass spectrometry glycomics. In silico expression analysis of α2-3 sialyltransferase ST3Gal IV and SLe^x protein carrier was performed and the conjoint expression of the SLe^x modified glycoproteins evaluated by immunohistochemistry and PLA in a series of gastric carcinomas.

Results: Carcinoembryonic antigen (CEA; CEACAM5) was identified and validated by different methodologies as a major carrier of SLe^x. N-glycomics of CEA revealed that complex N-glycans are capped with α2-3 linked sialic acid (Neu5Acα2-3Galβ1-4GlcNAc). Data set analysis of ST3Gal IV and CEA showed that ST3Gal IV expression was associated with patient´s poor survival, whereas CEA did not show any prognostic value. The co-expression of both CEA and SLe^X was observed in 86,3% of gastric carcinoma cases and 74,5% of the total cases displayed the conjoint CEA+SLe^xin situ PLA expression. This expression was associated with clinicopathological features of the tumors, including infiltrative pattern of tumor growth, presence of venous invasion and patient's poor survival. CEA immunoprecipitation from gastric carcinoma tissues also confirmed the presence of SLe^x.

Conclusion: CEA is the major glycoprotein carrying SLe^x in gastric carcinoma and the conjoint detection of CEA-SLe^x is associated with aggressive tumor features highlighting its PLA detection as a biomarker of gastric cancer patient prognosis for theranostic applications.

Targeted Approaches to Inhibit Sialylation of Multiple Myeloma in the Bone Marrow Microenvironment

Aberrant glycosylation modulates different aspects of tumor biology, and it has long been recognized as a hallmark of cancer. Among the different forms of glycosylation, sialylation, the addition of sialic acid to underlying oligosaccharides, is often dysregulated in cancer. Increased expression of sialylated glycans has been observed in many types of cancer, including multiple myeloma, and often correlates with aggressive metastatic behavior. Myeloma, a cancer of plasma cells, develops in the bone marrow, and colonizes multiple sites of the skeleton including the skull. In myeloma, the bone marrow represents an essential niche where the malignant cells are nurtured by the microenvironment and protected from chemotherapy. Here, we discuss the role of hypersialylation in the metastatic process focusing on multiple myeloma. In particular, we examine how increased sialylation modulates homing of malignant plasma cells into the bone marrow by regulating the activity of molecules important in bone marrow cellular trafficking including selectins and integrins. We also propose that inhibiting sialylation may represent a new therapeutic strategy to overcome bone marrow-mediated chemotherapy resistance and describe different targeted approaches to specifically deliver sialylation inhibitors to the bone marrow microenvironment.

Glycointeractions in bacterial pathogenesis

Many important interactions between bacterial pathogens and their hosts are highly specific binding events that involve host or pathogen carbohydrate structures (glycans). Glycan interactions can mediate adhesion, invasion and immune evasion and can act as receptors for toxins. Several bacterial pathogens can also enzymatically alter host glycans to reveal binding targets, degrade the host cell glycans or alter the function of host glycoproteins. In recent years, high-throughput screening technologies, such as lectin, glycan and mucin microarrays, have transformed the field by identifying new bacterial-host glycointeractions, which are crucial for colonization, persistence and disease. In this Review, we discuss interactions involving both host and bacterial glycans that have a role in bacterial pathogenesis. We also highlight recent technological advances that have illuminated the glycoscience of microbial pathogenesis.

An Atlas of Human Glycosylation Pathways Enables Display of the Human Glycome by Gene Engineered Cells

The structural diversity of glycans on cells-the glycome-is vast and complex to decipher. Glycan arrays display oligosaccharides and are used to report glycan hapten binding epitopes. Glycan arrays are limited resources and present saccharides without the context of other glycans and glycoconjugates. We used maps of glycosylation pathways to generate a library of isogenic HEK293 cells with combinatorially engineered glycosylation capacities designed to display and dissect the genetic, biosynthetic, and structural basis for glycan binding in a natural context. The cell-based glycan array is self-renewable and reports glycosyltransferase genes required (or blocking) for interactions through logical sequential biosynthetic steps, which is predictive of structural glycan features involved and provides instructions for synthesis, recombinant production, and genetic dissection strategies. Broad utility of the cell-based glycan array is demonstrated, and we uncover higher order binding of microbial adhesins to clustered patches of O-glycans organized by their presentation on proteins.

Sialyl Lewisx-P-selectin cascade mediates tumor-mesothelial adhesion in ascitic fluid shear flow

Organ-specific colonization suggests that specific cell–cell recognition is essential. Yet, very little is known about this particular interaction. Moreover, tumor cell lodgement requires binding under shear stress, but not static, conditions. Here, we successfully isolate the metastatic populations of cancer stem/tumor-initiating cells (M-CSCs). We show that the M-CSCs tether more and roll slower than the non-metastatic (NM)-CSCs, thus resulting in the preferential binding to the peritoneal mesothelium under ascitic fluid shear stress. Mechanistically, this interaction is mediated by P-selectin expressed by the peritoneal mesothelium. Insulin-like growth factor receptor-1 carrying an uncommon non-sulfated sialyl-Lewis^x (sLe^x) epitope serves as a distinct P-selectin binding determinant. Several glycosyltransferases, particularly α1,3-fucosyltransferase with rate-limiting activity for sLe^x synthesis, are highly expressed in M-CSCs. Tumor xenografts and clinical samples corroborate the relevance of these findings. These data advance our understanding on the molecular regulation of peritoneal metastasis and support the therapeutic potential of targeting the sLe^x-P-selectin cascade.

Tumor cell in the peritoneum are often exposed to shear forces generated by ascitic flow during metastasis. Here, the authors show that metastatic cancer stem cells tether more and roll slower than the non-metastatic counterparts, and that sialyl-Lewis^x -P-selectin axis mediates peritoneal metastasis.

Anti-ganglioside Antibodies in Peripheral Nerve Pathology

Anti-ganglioside antibodies are principally associated with autoimmune peripheral neuropathies. In these disorders, immune attack is inadvertently directed at peripheral nerve by autoantibodies that target glycan structures borne by glycolipids, particularly gangliosides concentrated in nerve myelin and axons. The most thoroughly studied disorder is the acute paralytic disease, Guillain-Barré syndrome (GBS) in which IgG autoantibodies against gangliosides arise following acute infections, notably Campylobacter jejuni enteritis. Additionally, chronic autoimmune neuropathies are associated with IgM antibodies directed against many glycolipids including gangliosides. This introductory chapter briefly summarizes the immunological and pathological features of these disorders, focusing on the methodological development of antibody measurement and of animal models.

Adaptive Multifunctional Supramolecular Assemblies of Glycopeptides Rapidly Enable Morphogenesis

Despite the well-established biophysical principle of adhesion-guided in vitro morphogenesis, there are few single synthetic molecular species that can rapidly enable morphogenesis (e.g., a cell monolayer to cell spheroids) in a cell culture because adhesion inherently involves many signals. Here we show the use of adaptive multifunctional supramolecular assemblies of glycopeptides, consisting of cell adhesion sequence and saccharide, to induce cell spheroids rapidly from a monolayer of cells. Having a general architecture of N-terminal capping, glycosylation, and an integrin-binding sequence, the glycopeptides self-assemble to form a dynamic continuum of nanostructures (i.e., from nanoparticles to nanofibers) to affect the interactions of integrins, E-selectin, and cadherins with their natural ligands and to act adaptively according to the cellular environment. Such adaptive (i.e., context-dependent) interactions weaken cell-substratum adhesion and enhance intercellular interactions, which rapidly and transiently induce cell spheroids. This work illustrates the use of supramolecular assemblies of simple glycopeptides to modulate biophysical conditions for regulating cell functions, which is a new approach for developing biomaterials.

The effect of carbohydrate structures on the hydrogelation ability and morphology of self-assembled structures of peptide-carbohydrate conjugates in water

We describe the construction of peptide-carbohydrate conjugates, namely glycopeptides, capable of self-assembling in water. We found that disaccharide structures (epimer or glycosidic-bond geometry) appended to the glycopeptides have a noticeable effect on the hydrogel formation ability as well as the morphology of the self-assembled structures. The soft materials consisting of self-assembled structures with carbohydrates on their surface and various types of morphologies might be useful as matrices to investigate the function of carbohydrates in biological events.

Role of Integrin Signaling Activation on the Development of Human T Cell Leukemia Virus-1 (HTLV-1)-Associated Myelopathy/Tropical Spastic Paraparesis: Its Relationship to HTLV-1-Infected CD4+ T Cell Transmigrating Activity into the Tissues

The main clinical feature of human T cell leukemia virus-1 (HTLV-1)-associated myelopathy/tropical spastic paraparesis (HAM/TSP) is slowly progressive spastic paraparesis with bladder dysfunction. HAM/TSP is induced by chronic inflammation in the spinal cord, mainly the lower thoracic cord. A long-standing bystander mechanism, such as the destruction of surrounding tissues by the interaction between infiltrated Th1-like, HTLV-1-infected CD4⁺ T cells and HTLV-1-specific CD8⁺ cytotoxic T cells (CTL), is probably critical for the induction of chronic inflammation. Although the HTLV-1-infected CD4⁺ T cells in HAM/TSP appear to play a crucial role in the initial pathogenesis of HAM/TSP, the exact mechanisms of how these cells acquire their function as the first responders in the pathogenesis of HAM/TSP still remain unresolved. Herein, we propose the importance of the activation of both outside-in signals from integrin signaling and inside-out signals for integrin signaling in the HTLV-1-infected CD4⁺ T cells of HAM/TSP patients.

Soluble Selectin Levels in Patients with Lung Cancer

Increased expression of selectins has been found on endothelial cells of venules and capillaries in the tumor stroma of non-small cell lung cancer, suggesting their functional role in the process of chemotaxis for tumor cells. The present study was aimed at analyzing the role of both soluble (s)P-selectin and sE-selectin levels in association with clinico-pathological variables in 116 patients with lung cancer, 38 patients with benign diseases and 59 healthy donors. The results obtained showed that sP-selectin and sE-selectin levels were higher in patients with lung cancer compared to normal donors (p<0.02 and p<0.005, respectively). No differences were observed among patients with various benign diseases for both selectins. Increased levels of sP-selectin and sE-selectin were significantly associated with squamous lung cancer at late stages (p<0.05), but not adenocarcinoma. Both sP- and sE-selectin were independently related to the stage of squamous lung cancer by stepwise regression analysis (p<0.02 and p<0.03, respectively), while only sE-selectin was independently related to the presence of distant metastasis in the same histotype (p<0.02). These results suggest that measurement of plasma soluble selectins might represent a useful laboratory parameter in the management of patients with squamous lung cancer.

Biomimetic nanoparticles for inflammation targeting

There have been many recent exciting developments in biomimetic nanoparticles for biomedical applications. Inflammation, a protective response involving immune cells, blood vessels, and molecular mediators directed against harmful stimuli, is closely associated with many human diseases. As a result, biomimetic nanoparticles mimicking immune cells can help achieve molecular imaging and precise drug delivery to these inflammatory sites. This review is focused on inflammation-targeting biomimetic nanoparticles and will provide an in-depth look at the design of these nanoparticles to maximize their benefits for disease diagnosis and treatment.

The role of mucin-educated platelet activation in tumor invasiveness: An unfolding concern in the realm of cancer biology

Metastasis is a complex and well-coordinated phenotypic transformation of cancer cells governed by aberrant genetic and molecular pathways. It has been approved as the most consistent cause of cancer death. With emerging insight into the genomics, transcriptomics and proteomics, progress has been made and reasonably large number of molecular pathways of metastasis has been forwarded, but our understanding of precise underlying molecular mechanisms remains largely scarce. It has been well-known for around a decade and more that platelets are intriguingly contributing to the cancer metastasis. However, it is only recently that cancer cells can activate platelets have started to become apparent. Surprisingly, platelets in response to cancer cell activation, supported by research observations, allow cancer cells to escape immune removal, prolong survival in vascular compartment, increased cellular adhesion and develop new cellular niches which eventually help to favor cancer metastasis. Although a widely acknowledged plausible explanation that cancer cells activate platelets to facilitate in their distant spread, the description of this remains to be confirmed. In recent years, mucins, heavily glycosylated peptide structure, have been introduced to be released by several types of cancer cells. They account for poor prognosis in wide array of malignancies, because of their significant ability to induce metastatic process. The mechanism responsible for their increased metastatic propensity remains uncharacterized, but recent work suggested the role of cancer expressed mucins in initiating platelet thrombus. The association of cancer yield mucins, platelets and metastasis therefore suggests a pressing need to explore novel molecular mechanisms and therapeutic targets thereafter.

SDA and IDA - Two aptamers to inhibit cancer cell adhesion

Aptamers which bind to proteins involved in cell-cell interactions could have significant value to directly affect cancer cell adhesion or for directed cargo delivery. Here, I discuss two aptamers: aptamer SDA which binds to E- and P-selectin, and aptamer IDA which binds to α6β4 integrin. Both aptamers (SDA 91 nt and IDA 77 nt) bind their target proteins with dissociation constants in the 100-150 nM range and substantially inhibit special cellular adhesion, possibly a first and pivotal step in transendothelial migration during metastasis formation. The aptamers' half-lives in cell culture media are between two and six hours. IDA is internalized by integrin presenting cells within minutes thus possibly serving as vehicle for directed cargo delivery.

Effect of circulating tumor cell aggregate configuration on hemodynamic transport and wall contact

Selectin-mediated adhesion of circulating tumor cells (CTCs) to the endothelium is a critical step in cancer metastasis, a major factor contributing to the mortality of cancer. The formation of tethers between tumor cells and endothelial selectins initiates cell rolling, which can lead to firm adhesion, extravasation and the formation of secondary metastases. Tumor cells travel through the bloodstream as single cells, or as aggregates known as circulating tumor microemboli (CTM). CTM have increased survivability and metastatic potential relative to CTCs, and the presence of CTM is associated with worse patient prognosis. The motion of cells and cellular aggregates in flow is a function of their size and shape, and these differences influence the frequency and strength of their contact with the endothelium. In this study, a computational model consisting of the hydrodynamic component of the Multiparticle Adhesive Dynamics simulation analyzed the effects of model aggregate conformation and orientation on adhesive binding potential. Model aggregates of the Colo205 colorectal cancer cell line were created, consisting of two, three, and four cells in simple geometrical conformations. Contact time, contact area, and time integral of contact area were measured as a function of fluid shear rate, initial centroid height, and initial orientation for model aggregates that experienced hydrodynamic collisions with the plane wall. It was found that larger CTM conformations with intermediate nonsphericities had the highest adhesion potential. The results of this study shed light on the correlation between environmental conditions and extravasation efficiency, which could inform the development of new anti-metastatic drugs.

Fucosyltransferase VII promotes proliferation via the EGFR/AKT/mTOR pathway in A549 cells

Fucosyltransferase VII (FUT7) is one of a1,3-fucosyltransferases family that catalyzes the final fucosylation step in the synthesis of Lewis antigens and generates a unique glycosylated product sialyl Lewis X (sLe^X). sLe^X can serve as ligands for E- or P-selectin expressed on the cell surface and results in cancer metastasis and angiogenesis. However, the molecular biological mechanisms of FUT7 elevation in neoplastic cells are still largely unknown. In this study, we examined the impact of FUT7 on cell proliferation and migration in A549 cells by colony formation assay, cell cycle assay, gelatin zymography, wound-healing assay, transwell invasion assay and Western blot. In addition, we identified that FUT7 activated EGFR/AKT/mTOR signal pathway that correlated with sLe^X augmentation. In conclusion, FUT7 overexpression augments sLe^X synthesis to trigger cell proliferation via the activation of EGFR/AKT/mTOR signaling pathway, which indicated that FUT7 may be a potential therapeutic target for epithelial cancers with a high expression of FUT7 and sLe^X.

Nanoparticles and targeted drug delivery in cancer therapy

Surgery, chemotherapy, radiotherapy, and hormone therapy are the main common anti-tumor therapeutic approaches. However, the non-specific targeting of cancer cells has made these approaches non-effective in the significant number of patients. Non-specific targeting of malignant cells also makes indispensable the application of the higher doses of drugs to reach the tumor region. Therefore, there are two main barriers in the way to reach the tumor area with maximum efficacy. The first, inhibition of drug delivery to healthy non-cancer cells and the second, the direct conduction of drugs into tumor site. Nanoparticles (NPs) are the new identified tools by which we can deliver drugs into tumor cells with minimum drug leakage into normal cells. Conjugation of NPs with ligands of cancer specific tumor biomarkers is a potent therapeutic approach to treat cancer diseases with the high efficacy. It has been shown that conjugation of nanocarriers with molecules such as antibodies and their variable fragments, peptides, nucleic aptamers, vitamins, and carbohydrates can lead to effective targeted drug delivery to cancer cells and thereby cancer attenuation. In this review, we will discuss on the efficacy of the different targeting approaches used for targeted drug delivery to malignant cells by NPs.