Intercellular adhesion molecule-1 suppresses TMZ chemosensitivity in acquired TMZ-resistant gliomas by increasing assembly of ABCB1 on the membrane.

AIMS: Despite aggressive treatment, the recurrence of glioma is an inevitable occurrence, leading to unsatisfactory clinical outcomes. A plausible explanation for this phenomenon is the phenotypic alterations that glioma cells undergo aggressive therapies, such as TMZ-therapy. However, the underlying mechanisms behind these changes are not well understood. METHODS: The TMZ chemotherapy resistance model was employed to assess the expression of intercellular adhesion molecule-1 (ICAM1) in both in vitro and in vivo settings. The potential role of ICAM1 in regulating TMZ chemotherapy resistance was investigated through knockout and overexpression techniques. Furthermore, the mechanism underlying ICAM1-mediated TMZ chemotherapy resistance was examined using diverse molecular biological methods, and the lipid raft protein was subsequently isolated to investigate the cellular subcomponents where ICAM1 operates. RESULTS: Acquired TMZ resistant (TMZ-R) glioma models heightened production of intercellular adhesion molecule-1 (ICAM1) in TMZ-R glioma cells. Additionally, we observed a significant suppression of TMZ-R glioma proliferation upon inhibition of ICAM1, which was attributed to the enhanced intracellular accumulation of TMZ. Our findings provide evidence supporting the role of ICAM1, a proinflammatory marker, in promoting the expression of ABCB1 on the cell membrane of TMZ-resistant cells. We have elucidated the mechanistic pathway by which ICAM1 modulates phosphorylated moesin, leading to an increase in ABCB1 expression on the membrane. Furthermore, our research has revealed that the regulation of moesin by ICAM1 was instrumental in facilitating the assembly of ABCB1 exclusively on the lipid raft of the membrane. CONCLUSIONS: Our findings suggest that ICAM1 is an important mediator in TMZ-resistant gliomas and targeting ICAM1 may provide a new strategy for enhancing the efficacy of TMZ therapy against glioma.

Moesin deficiency leads to lupus-like nephritis with accumulation of CXCL13-producing patrolling monocytes.

Moesin is a member of the ezrin-radixin-moesin (ERM) family of proteins that link plasma membrane proteins to the cortical cytoskeleton and thus regulate diverse cellular processes. Mutations in the human moesin gene cause a primary immunodeficiency called X-linked moesin-associated immunodeficiency (X-MAID), which may be complicated by an autoimmune phenotype with kidney involvement. We previously reported that moesin-deficient mice exhibit lymphopenia similar to that of X-MAID and develop a lupus-like autoimmune phenotype with age. However, the mechanism through which moesin defects cause kidney pathology remains obscure. Here, we characterized immune cell infiltration and chemokine expression in the kidney of moesin-deficient mice. We found accumulation of CD4+ T and CD11b+ myeloid cells and high expression of CXCL13, whose upregulation was detected before the onset of overt nephritis. CD4+ T cell population contained IFN-γ-producing effectors and expressed the CXCL13 receptor CXCR5. Among myeloid cells, Ly6Clo patrolling monocytes and MHCIIlo macrophages markedly accumulated in moesin-deficient kidneys and expressed high CXCL13 levels, implicating the CXCL13-CXCR5 axis in nephritis development. Functionally, Ly6Clo monocytes from moesin-deficient mice showed reduced migration toward sphingosine 1-phosphate. These findings suggest that moesin plays a role in regulating patrolling monocyte homeostasis, and that its defects lead to nephritis associated with accumulation of CXCL13-producing monocytes and macrophages.

A bipartite NLS motif mediates the nuclear import of Drosophila moesin.

The ERM protein family, which consists of three closely related proteins in vertebrates, ezrin, radixin, and moesin (ERM), is an ancient and important group of cytoplasmic actin-binding and organizing proteins. With their FERM domain, ERMs bind various transmembrane proteins and anchor them to the actin cortex through their C-terminal F-actin binding domain, thus they are major regulators of actin dynamics in the cell. ERMs participate in many fundamental cellular processes, such as phagocytosis, microvilli formation, T-cell activation and tumor metastasis. We have previously shown that, besides its cytoplasmic activities, the single ERM protein of Drosophila melanogaster, moesin, is also present in the cell nucleus, where it participates in gene expression and mRNA export. Here we study the mechanism by which moesin enters the nucleus. We show that the nuclear import of moesin is an NLS-mediated, active process. The nuclear localization sequence of the moesin protein is an evolutionarily highly conserved, conventional bipartite motif located on the surface of the FERM domain. Our experiments also reveal that the nuclear import of moesin does not require PIP2 binding or protein activation, and occurs in monomeric form. We propose, that the balance between the phosphorylated and non-phosphorylated protein pools determines the degree of nuclear import of moesin.

ICAMs in Immunity, Intercellular Adhesion and Communication.

Interactions among leukocytes and leukocytes with immune-associated auxiliary cells represent an essential feature of the immune response that requires the involvement of cell adhesion molecules (CAMs). In the immune system, CAMs include a wide range of members pertaining to different structural and functional families involved in cell development, activation, differentiation and migration. Among them, ß2 integrins (LFA-1, Mac-1, p150,95 and αDß2) are predominantly involved in homotypic and heterotypic leukocyte adhesion. ß2 integrins bind to intercellular (I)CAMs, actin cytoskeleton-linked receptors belonging to immunoglobulin superfamily (IgSF)-CAMs expressed by leukocytes and vascular endothelial cells, enabling leukocyte activation and transendothelial migration. ß2 integrins have long been viewed as the most important ICAMs partners, propagating intracellular signalling from ß2 integrin-ICAM adhesion receptor interaction. In this review, we present previous evidence from pioneering studies and more recent findings supporting an important role for ICAMs in signal transduction. We also discuss the contribution of immune ICAMs (ICAM-1, -2, and -3) to reciprocal cell signalling and function in processes in which ß2 integrins supposedly take the lead, paying particular attention to T cell activation, differentiation and migration.

Redistribution of the glycocalyx exposes phagocytic determinants on apoptotic cells.

Phagocytes remove dead and dying cells by engaging "eat-me" ligands such as phosphatidylserine (PtdSer) on the surface of apoptotic targets. However, PtdSer is obscured by the bulky exofacial glycocalyx, which also exposes ligands that activate "don't-eat-me" receptors such as Siglecs. Clearly, unshielding the juxtamembrane "eat-me" ligands is required for the successful engulfment of apoptotic cells, but the mechanisms underlying this process have not been described. Using human and murine cells, we find that apoptosis-induced retraction and weakening of the cytoskeleton that anchors transmembrane proteins cause an inhomogeneous redistribution of the glycocalyx: actin-depleted blebs emerge, lacking the glycocalyx, while the rest of the apoptotic cell body retains sufficient actin to tether the glycocalyx in place. Thus, apoptotic blebs can be engaged by phagocytes and are targeted for engulfment. Therefore, in cells with an elaborate glycocalyx, such as mucinous cancer cells, this "don't-come-close-to-me" barrier must be removed to enable clearance by phagocytosis.

The role of moesin in diagnosing and assessing severity of lymphangioleiomyomatosis.

BACKGROUND: Lymphangioleiomyomatosis (LAM) is a rare disease which is easily misdiagnosed. Vascular endothelial growth factor D (VEGF-D), as the most common biomarker, however, is not so perfect for the diagnosis and severity assessment of LAM. MATERIALS AND METHODS: The isobaric tags for relative and absolute quantitation (iTRAQ)-based method was used to identify a cytoskeleton protein, moesin. 84 patients with LAM, 44 patients with other cystic lung diseases (OCLDs), and 37 healthy control subjects were recruited for collecting blood samples and clinical data. The levels of moesin in serum were evaluated by ELISA. The relationships of moesin with lymphatic involvement, lung function, and treatment decision were explored in patients with LAM. RESULTS: The candidate protein moesin was identified by the proteomics-based bioinformatic analysis. The serum levels of moesin were higher in patients with LAM [219.0 (118.7-260.5) pg/mL] than in patients with OCLDs (125.8 ± 59.9 pg/mL, P < 0.0001) and healthy women [49.6 (35.5-78.9) ng/mL, P < 0.0001]. Moesin had an area under the receiver operator characteristic curve (AUC) of 0.929 for predicting LAM diagnosis compared to healthy women (sensitivity 81.0%, specificity 94.6%). The combination of moesin and VEGF-D made a better prediction in differentiating LAM from OCLDs than moesin or VEGF-D alone. Moreover, elevated levels of moesin were related to lymphatic involvement in patients with LAM. Moesin was found negatively correlated with FEV1%pred, FEV1/FVC, and DLCO%pred (P = 0.0181, r = - 0.3398; P = 0.0067, r = - 0.3863; P = 0.0010, r = - 0.4744). A composite score combining moesin and VEGF-D improved prediction for sirolimus treatment, compared with each biomarker alone. CONCLUSION: Higher levels of moesin in serum may indicate impaired lung function and lymphatic involvement in patients with LAM, suggest a more serious condition, and provide clinical guidance for sirolimus treatment.

Moesin affects the plasma membrane expression and the immune checkpoint function of CD47 in human ovarian clear cell carcinoma.

Among major histological subtypes of epithelial ovarian cancer, a higher incidence of ovarian clear cell carcinoma (OCCC) is observed in East Asian populations, particularly in Japan. Despite recent progress in the immune checkpoint inhibitors for a wide variety of cancer cell types, patients with OCCC exhibit considerably low response rates to these drugs. Hence, urgent efforts are needed to develop a novel immunotherapeutic approach for OCCC. CD47, a transmembrane protein, is overexpressed in almost all cancer cells and disrupts macrophage phagocytic activity in cancer cells. Ezrin-Radixin-Moesin (ERM) family member of proteins serve as scaffold proteins by crosslinking certain transmembrane proteins with the actin cytoskeleton, contributing to their plasma membrane localization. Here, we examined the role of ERM family in the plasma membrane localization and functionality of CD47 in OCCC cell lines derived from Japanese women. Confocal laser scanning microscopy analysis showed colocalization of CD47 with all three ERM in the plasma membrane of OCCC cells. RNA interference-mediated gene silencing of moesin, but not others, decreased the plasma membrane expression and immune checkpoint function of CD47, as determined by flow cytometry and in vitro phagocytosis assay using human macrophage-like cells, respectively. Interestingly, clinical database analysis indicated that moesin expression in OCCC was higher than that in other histological subtypes of ovarian cancers, and the expression of CD47 and moesin increased with the cancer stage. In conclusion, moesin is overexpressed in OCCC and may be the predominant scaffold protein responsible for CD47 plasma membrane localization and function in OCCC.

Identification of high-performing antibodies for Moesin for use in Western Blot, immunoprecipitation, and immunofluorescence.

Moesin is a cytoskeletal adaptor protein, involved in the modification of the actin cytoskeleton, with relevance to Alzheimer's Disease. Well characterized anti-Moesin antibodies would benefit the scientific community. In this study, we have characterized ten Moesin commercial antibodies in Western Blot, immunoprecipitation, and immunofluorescence using a standardized experimental protocol based on comparing read-outs in knockout cell lines and isogenic parental controls. These studies are part of a larger, collaborative initiative seeking to address antibody reproducibility by characterizing commercially available antibodies for human proteins and publishing the results openly as a resource for the scientific community. While use of antibodies and protocols vary between laboratories, we encourage readers to use this report as a guide to select the most appropriate antibodies for their specific needs.

Discovery of FERM domain protein-protein interaction inhibitors for MSN and CD44 as a potential therapeutic approach for Alzheimer's disease.

Proteomic studies have identified moesin (MSN), a protein containing a four-point-one, ezrin, radixin, moesin (FERM) domain, and the receptor CD44 as hub proteins found within a coexpression module strongly linked to Alzheimer's disease (AD) traits and microglia. These proteins are more abundant in Alzheimer's patient brains, and their levels are positively correlated with cognitive decline, amyloid plaque deposition, and neurofibrillary tangle burden. The MSN FERM domain interacts with the phospholipid phosphatidylinositol 4,5-bisphosphate (PIP2) and the cytoplasmic tail of CD44. Inhibiting the MSN-CD44 interaction may help limit AD-associated neuronal damage. Here, we investigated the feasibility of developing inhibitors that target this protein-protein interaction. We have employed structural, mutational, and phage-display studies to examine how CD44 binds to the FERM domain of MSN. Interestingly, we have identified an allosteric site located close to the PIP2 binding pocket that influences CD44 binding. These findings suggest a mechanism in which PIP2 binding to the FERM domain stimulates CD44 binding through an allosteric effect, leading to the formation of a neighboring pocket capable of accommodating a receptor tail. Furthermore, high-throughput screening of a chemical library identified two compounds that disrupt the MSN-CD44 interaction. One compound series was further optimized for biochemical activity, specificity, and solubility. Our results suggest that the FERM domain holds potential as a drug development target. Small molecule preliminary leads generated from this study could serve as a foundation for additional medicinal chemistry efforts with the goal of controlling microglial activity in AD by modifying the MSN-CD44 interaction.

Moesin and Ezrin as New Promising Markers for Early Detection of Endometrial Carcinoma: An Immunohistochemical Study.

OBJECTIVE: the aim of this study is to evaluate immunohistochemically the expression of ezrin, and moesin, in endometrial lesion cases in order to detect EC at early stages which will have an important implication on the patients' outcome. METHOD: 100 stored, formalin-fixed, paraffin-embedded tissue blocks of endometrial curettage obtained due to abnormal uterine bleeding or postmenopausal bleeding were collected. Each paraffin block was re-cut by rotatory microtome at 4 µm thickness then mounted on a glass slide and stained by hematoxylin and eosin for routine histopathological examination and on charged slides for immunohistochemistry using an automated staining system (Dako autostainer link 48) with antibodies against Moesin and Ezrin. Cytoplasmic staining was evaluated for both Moesin and Ezrin based on the intensity and extent of staining and scored for each sample. RESULT: Both Moesin and Ezrin were significantly higher in atypical endometrial hyperplasia compared to benign hyperplasia and significantly higher in endometrial carcinoma compared to atypical hyperplasia. Moesin also significantly correlated with higher tumor grades while Ezrin was significantly higher in postmenopausal women denoting their role in tumor progression and poor prognosis. CONCLUSION: Both Moesin and Ezrin could be potentially used as predictive markers for endometrial carcinoma screening programmes as well as indicators for cancer progression.

Potential Role of Moesin in Regulating Mast Cell Secretion.

Mast cells have existed for millions of years in species that never suffer from allergic reactions. Hence, in addition to allergies, mast cells can play a critical role in homeostasis and inflammation via secretion of numerous vasoactive, pro-inflammatory and neuro-sensitizing mediators. Secretion may utilize different modes that involve the cytoskeleton, but our understanding of the molecular mechanisms regulating secretion is still not well understood. The Ezrin/Radixin/Moesin (ERM) family of proteins is involved in linking cell surface-initiated signaling to the actin cytoskeleton. However, how ERMs may regulate secretion from mast cells is still poorly understood. ERMs contain two functional domains connected through a long α-helix region, the N-terminal FERM (band 4.1 protein-ERM) domain and the C-terminal ERM association domain (C-ERMAD). The FERM domain and the C-ERMAD can bind to each other in a head-to-tail manner, leading to a closed/inactive conformation. Typically, phosphorylation on the C-terminus Thr has been associated with the activation of ERMs, including secretion from macrophages and platelets. It has previously been shown that the ability of the so-called mast cell "stabilizer" disodium cromoglycate (cromolyn) to inhibit secretion from rat mast cells closely paralleled the phosphorylation of a 78 kDa protein, which was subsequently shown to be moesin, a member of ERMs. Interestingly, the phosphorylation of moesin during the inhibition of mast cell secretion was on the N-terminal Ser56/74 and Thr66 residues. This phosphorylation pattern could lock moesin in its inactive state and render it inaccessible to binding to the Soluble NSF attachment protein receptors (SNAREs) and synaptosomal-associated proteins (SNAPs) critical for exocytosis. Using confocal microscopic imaging, we showed moesin was found to colocalize with actin and cluster around secretory granules during inhibition of secretion. In conclusion, the phosphorylation pattern and localization of moesin may be important in the regulation of mast cell secretion and could be targeted for the development of effective inhibitors of secretion of allergic and inflammatory mediators from mast cells.

Suppression of osteosarcoma progression by engineered lymphocyte-derived proteomes.

Cancer cells tend to develop resistance to chemotherapy and enhance aggressiveness. A counterintuitive approach is to tame aggressiveness by an agent that acts opposite to chemotherapeutic agents. Based on this strategy, induced tumor-suppressing cells (iTSCs) have been generated from tumor cells and mesenchymal stem cells. Here, we examined the possibility of generating iTSCs from lymphocytes by activating PKA signaling for suppressing the progression of osteosarcoma (OS). While lymphocyte-derived CM did not present anti-tumor capabilities, the activation of PKA converted them into iTSCs. Inhibiting PKA conversely generated tumor-promotive secretomes. In a mouse model, PKA-activated CM suppressed tumor-induced bone destruction. Proteomics analysis revealed that moesin (MSN) and calreticulin (Calr), which are highly expressed intracellular proteins in many cancers, were enriched in PKA-activated CM, and they acted as extracellular tumor suppressors through CD44, CD47, and CD91. The study presented a unique option for cancer treatment by generating iTSCs that secret tumor-suppressive proteins such as MSN and Calr. We envision that identifying these tumor suppressors and predicting their binding partners such as CD44, which is an FDA-approved oncogenic target to be inhibited, may contribute to developing targeted protein therapy.

Identification of Moesin (MSN) as a Potential Therapeutic Target for Colorectal Cancer via the ß-Catenin-RUNX2 Axis.

CRC is the second leading cause of cancer-related death. The complex mechanisms of metastatic CRC limit available therapeutic choice. Thus, identifying new CRC therapeutic targets is essential. Moesin (MSN), a member of the ezrin-radixin-moesin family, connects the cell membrane to the actin-based cytoskeleton and regulates cell morphology. We investigated the role of MSN in the progression of CRC. GENT2 and oncomine were used to study MSN expression and CRC patient outcomes. MSN-specific shRNAs or MSN-overexpressed plasmid were used to establish MSN-KD and MSN overexpressed cell lines, respectively. SRB, migration, wound healing, and flow cytometry were used to test cell survival and migration. Propidium iodide and annexin V stain were used to analyze the cell cycle and apoptosis. MSN expression was found to be higher in CRC tissues than in normal tissues. Higher MSN expression is associated with poor overall survival, disease-free survival, and relapse-free survival rates in CRC patients. MSN silencing inhibits cell proliferation, adhesion, migration, and invasion in vitro, whereas MSN overexpression accelerates cell proliferation, adhesion, migration, and invasion. RNA sequencing was used to investigate differentially expressed genes, and RUNX2 was discovered as a possible downstream target for MSN. In CRC patients, RUNX2 expression was significantly correlated with MSN expression. We also found that MSN silencing decreased cytoplasmic and nuclear ß-catenin levels. Additionally, pharmacological inhibition of ß-catenin in MSN-overexpressed cells led to a reduction of RUNX2, and activating ß-catenin signaling by inhibiting GSK3ß rescued the RUNX2 downregulation in MSN-KD cells. This confirms that MSN regulates RUNX2 expression via activation of ß-catenin signaling. Finally, our result further determined that RUNX2 silencing reduced the ability of MSN overexpression cells to proliferate and migrate. MSN accelerated CRC progression via the ß-catenin-RUNX2 axis. As a result, MSN holds the potential to become a new target for CRC treatment.

Comparative Study of Immunohistochemical Expression of Moesin and FLOT 1 in OSCC and Their Correlation with Histopathological Prognostic Factors.

AIM: To study immunohistochemical (IHC) expression patterns of Moesin and FLOT 1 in oral squamous cell carcinoma (OSCC) and to correlate it with histopathological prognostic factors. MATERIALS AND METHODS: A cross-sectional study design was conducted on histopathologically diagnosed cases of OSCC. The inclusion criteria were carcinoma of buccal mucosa, tongue, alveolar mucosa, palate, gingiva, the floor of the mouth, retromolar area, and soft palate. The exclusion criteria included cases of squamous cell carcinoma from sites other than the oral cavity, potentially malignant disorders (PMDs), and any pseudomalignancies of the head and neck. Tissue sections were subjected to IHC staining for Moesin and FLOT 1 and the results were subjected to statistical analysis. RESULTS: Moesin showed strong positivity and was significantly associated with the histopathological variables such as lymph nodes and the worst pattern of invasion, whereas FLOT 1 was not associated with any clinical, histopathological, or demographical variable in this study. CONCLUSION: Cytoplasmic detection of Moesin (35.19%) was higher than FLOT 1 (15.74%). There was no statistically significant relationship between the grade of the lesion and Moesin and FLOT 1. CLINICAL SIGNIFICANCE: New emerging prognostic biomarkers can aid to assess the rate of malignant transformation (epigenetic and molecular changes), thereby resulting in early prophylactic conciliation of the disease progression in OSCC. There is an urgent need for introducing these as an interventional therapy for effectively addressing OSCC at an early stage, thus preventing it from further proceeding to the advanced severe stage.

Radixin modulates the plasma membrane localization of CD47 in human uterine cervical adenocarcinoma cells.

Despite the dramatic success of immune checkpoint blockers in treating numerous cancer cell types, current therapeutic modalities provide clinical benefits to a subset of patients with cervical cancers. CD47 is commonly overexpressed in a broad variety of cancer cells, correlates with poor clinical prognosis, and acts as a dominant macrophage checkpoint by interacting with receptors expressed on macrophages. It allows cancer cells to escape from the innate immune system and hence is a potential therapeutic target for developing novel macrophage checkpoint blockade immunotherapies. As the intracellular scaffold proteins, ezrin/radixin/moesin (ERM) family proteins post-translationally regulate the cellular membrane localization of numerous transmembrane proteins, by crosslinking them with the actin cytoskeleton. We demonstrated that radixin modulates the plasma membrane localization and functionality of CD47 in HeLa cells. Immunofluorescence analysis and co-immunoprecipitation assay using anti-CD47 antibody showed the colocalization of CD47 and all three ERM families in the plasma membrane, and the molecular interactions between CD47 and all three ERM. Interestingly, gene silencing of only radixin, reduced the CD47 plasma membrane localization and functionality by means of flow cytometry and phagocytosis assay but had little influence on its mRNA expression. Together, in HeLa cells radixin may function as a principal scaffold protein responsible for the CD47 plasma membrane localization.

To evaluate an association between prognostic significance of Moesin with histopathological grading of oral squamous cell carcinoma: A systematic review.

Purpose: The aim of the present Aetiology/Risk type and Prognostic type of systematic review is to evaluate the value of Moesin as a biomarker of invasiveness in Oral Squamous Cell Carcinoma patients and to review/assess the available evidence regarding the prospective prognostic association between Moesin and histopathological grading of OSCC to enhance the quality of life and survival rate of oral cancer patients. Method: A systematic wide-range literature search was performed by authors (BS, KS, and DK) till October 2022 using both, electronic search media and manual search by hand, searching appropriate journals as per the focussed guiding question and inclusion/exclusion criteria. Major databases such as Scopus, EMBASE, Web of Science, Cochrane central register for controlled trials, PubMed & Google Scholar were conducted by two calibrated reviewers independently to gauge the association between the prognostic significance of Moesin with histopathological grading of oral squamous cell carcinoma. As this study is based on tissue samples of oral squamous cell carcinoma patients, all the selected studies were mostly, cross-sectional studies, and retrospective in nature. The studies were integrated with this review to gauge the association between the prognostic significance of Moesin with histopathological grading of oral squamous cell carcinoma (OSCC). The review included a total of 7 studies with tissue samples of 645 cases. The prime outcome was to assess the immunoexpression of Moesin among the different histopathological grades i.e well-differentiated SCC, moderately differentiated SCC, and poorly differentiated SCC and the subordinate outcome was to consider the extent of strong immunoexpression characteristics (cytoplasmic, membranous and mixed type) in different grades of OSCC as well as to correlate with morbidity, mortality, and/or 5 years or 10 years survival rate. Results: The results were analyzed and presented narratively using the Critical Appraisal Tools developed by the University Of Oxford; Risk of Bias - Cochrane Risk of Bias tool - RoB 2.0, and GRADE-pro (Grading of Recommendations, Assessment, Development, and Evaluations) which rates the features of the evidence as high, moderate, low and very low. The risk of mortality expressed in terms of Hazard ratio has been elicited as a 1.37 times higher rate of mortality in the advanced histopathological stages of the OSCC cases. As the sample size of this review was insignificant, therefore, the authors have incorporated hazard ratios of some other studies of carcinomas in diverse sites in the body to give a flavor of prognostic outcomes of Moesin. It was observed that Moesin expression in Breast cancer and UADT carcinomas have a higher mortality rate as compared to OSCC and lung carcinoma cases and this decree strengthens our conviction that Moesin expression in the cytoplasm of advanced histopathological stages of cancer can be assumed as a sign of poor prognosis in all carcinomas including OSCC patients. Conclusion: A sample of seven studies is inadequate as definite evidence for claiming that Moesin is a strong biomarker of invasiveness in OSCC cases and more clinical trials need to be conducted on the prognostic efficacy of Moesin expression in the various histopathological grades of OSCC cases.

Cellular Membrane Localization of Innate Immune Checkpoint Molecule CD47 Is Regulated by Radixin in Human Pancreatic Ductal Adenocarcinoma Cells.

In the past decade, immune checkpoint inhibitors have exhibited potent antitumor efficacy against multiple solid malignancies but limited efficacy against pancreatic ductal adenocarcinoma (PDAC). Cluster of differentiation (CD) 47, a member of the immunoglobulin G superfamily, is overexpressed in the surface membrane of PDAC and independently correlates with a worse clinical prognosis. Furthermore, CD47 functions as a dominant macrophage checkpoint, providing a potent "do not eat me" signal to enable cancer cells to evade the innate immune system. Thus, the blockade of CD47 is a promising immunotherapeutic strategy for PDAC. In this study, we determined whether ezrin/radixin/moesin (ERM) family members, which post-translationally modulate the cellular membrane localization of numerous transmembrane proteins by crosslinking with the actin cytoskeleton, contribute to the cellular membrane localization of CD47 in KP-2 cells derived from human PDAC. Immunofluorescence analysis showed that CD47 and ezrin/radixin were highly co-localized in the plasma membrane. Interestingly, gene silencing of radixin but not ezrin dramatically decreased the cell surface expression of CD47 but had little effects on its mRNA level. Furthermore, CD47 and radixin interacted with each other, as determined by a co-immunoprecipitation assay. In conclusion, radixin regulates the cellular membrane localization of CD47 as a scaffold protein in KP-2 cells.

The role of anti-HMGB1 antibody and anti-moesin antibody in ANCA-associated vasculitis.

OBJECTIVE: The study aims to evaluate the role of anti-high mobility group box 1 (HMGB1) antibody and anti-moesin antibody in the diagnosis of antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) and its possible relationship with the different clinical manifestations. METHODS: The study involved 60 AAV patients, 58 patients with autoimmune disease other than AAV and 50 healthy subjects. The serum levels of anti-HMGB1 and anti-moesin antibodies were determined by enzyme-linked immunosorbent assay (ELISA), and the second determination was made 3 months after treatment of AAV patients. RESULTS: Serum levels of anti-HMGB1 and anti-moesin antibodies in AAV group were significantly higher than those in non-AAV group and HC group. The area under the curve (AUC) of anti-HMGB1 and anti-moesin in diagnosing AAV were 0.977 and 0.670, respectively. Anti-HMGB1 levels were significantly elevated in AAV patients with pulmonary involvement, while the concentrations of anti-moesin were significantly increased in patients with renal damage. Anti-moesin were positively correlated with BVAS (r=0.261, P=0.044), creatinine (r=0.296, P=0.024) and negatively correlated with complement C3 (r=-0.363, P=0.013). Besides, anti-moesin levels of active AAV patients were significantly higher than those in inactive patients. The concentrations of serum anti-HMGB1 could be significantly decreased after induction remission treatment (P<0.05). CONCLUSION: Anti-HMGB1 and anti-moesin antibodies play important roles in the diagnosis and prognosis of AAV, which may act as potential disease markers for AAV.

Intracellular and extracellular moesins differentially regulate Src activity and ß-catenin translocation to the nucleus in breast cancer cells.

It is increasingly recognized that a single protein can have multiple, sometimes paradoxical, roles in cell functions as well as pathological conditions depending on its cellular locations. Here we report that moesins (MSNs) in the intracellular and extracellular domains present opposing roles in pro-tumorigenic signaling in breast cancer cells. Using live cell imaging with fluorescence resonance energy transfer (FRET)- and green fluorescent protein (GFP)-based biosensors, we investigated the molecular mechanism underlying the cellular location-dependent effect of MSN on Src and ß-catenin signaling in MDA-MB-231 breast cancer cells. Inhibition of intracellular MSN decreased the activities of Src and FAK, whereas overexpression of intracellular MSN increased them. By contrast, extracellular MSN decreased the activities of Src, FAK, and RhoA, as well as ß-catenin translocation to the nucleus. Consistently, Western blotting and MTT-based analysis showed that overexpression of intracellular MSN elevated the expression of oncogenic genes, such as p-Src, ß-catenin, Lrp5, MMP9, Runx2, and Snail, as well as cell viability, whereas extracellular MSN suppressed them. Conditioned medium derived from MSN-overexpressing mesenchymal stem cells or osteocytes showed the anti-tumor effects by inhibiting the Src activity and ß-catenin translocation to the nucleus as well as the activities of FAK and RhoA and MTT-based cell viability. Conditioned medium derived from MSN-inhibited cells increased the Src activity, but it did not affect the activities of FAK and RhoA. Silencing CD44 and/or FN1 in MDA-MB-231 cells blocked the suppression of Src activity and ß-catenin accumulation in the nucleus by extracellular MSN. Collectively, the results suggest that cellular location-specific MSN is a strong regulator of Src and ß-catenin signaling in breast cancer cells, and that extracellular MSN exerts tumor-suppressive effects via its interaction with CD44 and FN1.