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Heterogeneous extracellular vesicles (EVs) from various types of tumours are acknowledged for inducing the formation of pre-metastatic "niches" in draining lymph nodes (LNs) to promote lymphatic metastasis. In order to identify the specific subpopulations of EVs involved, we performed high-resolution proteomic analysis combined with nanoflow cytometry of bladder cancer (BCa) tissue-derived EVs to identify a novel subset of tumour-derived EVs that contain integrin α6 (ITGA6 + EVs) and revealed the positive correlation of ITGA6 + EVs with the formation of pre-metastatic niche in draining LNs and lymphatic metastasis in multicentre clinical analysis of 820-case BCa patients. BCa-derived ITGA6 + EVs induced E-selectin (SELE)-marked lymphatic remodelling pre-metastatic niche and promoted metastasis in draining LNs through delivering cargo circRNA-LIPAR to lymphatic endothelial cells in vivo and in vitro. Mechanistically, LIPAR linked ITGA6 to the switch II domain of RAB5A and sustained RAB5A GTP-bound activated state, thus maintaining the production of ITGA6 + EVs loaded with LIPAR through endosomal trafficking. ITGA6 + EVs targeted lymphatic vessels through ITGA6-CD151 interplay and released LIPAR to induce SELE overexpression-marked lymphatic remodelling pre-metastatic niche. Importantly, we constructed engineered-ITGA6 EVs to inhibit lymphatic pre-metastatic niche, which suppressed lymphatic metastasis and prolonged survival in preclinical models. Collectively, our study uncovers the mechanism of BCa-derived ITGA6 + EVs mediating pre-metastatic niche and provides an engineered-EV-based strategy against BCa lymphatic metastasis., (© 2024 The Author(s). Journal of Extracellular Vesicles published by Wiley Periodicals LLC on behalf of International Society for Extracellular Vesicles.)

Triple-negative breast cancer (TNBC) represents a significant health concern for women worldwide, and the overproduction of MMP9 and CD151 is associated with various cancers, influencing tumour growth and progression. This study aimed to investigate how CD151 and MMP9 affect TNBC cell migration, apoptosis, proliferation, and invasion. Immunohistochemical experiments revealed that CD151 and MMP9 were positively expressed in triple-negative breast cancer, and lymph node metastasis, the histological grade, and CD151 and MMP9 expression were found to be independent prognostic factors for the survival of patients with triple-negative breast cancer. Cytological experiments indicated that the knockdown of CD151 or MMP9 slowed triple-negative breast cancer cell growth, migration, and invasion and increased the apoptosis rate. Compared with CD151 knockdown, double MMP9 and CD151 knockdown further promoted cell death and inhibited TNBC cell proliferation, migration, and invasion. Moreover, β-catenin and p-GSK-3β were significantly downregulated. In summary, simultaneously silencing CD151 and MMP9 further suppressed the proliferation, migration and invasion of TNBC cells and promoted their apoptosis. One possible strategy for inducing this effect is to block the GSK-3β/β-catenin pathway., (© 2024. The Author(s).)

Abstract: Background: The recruitment of neutrophils to sites of localized injury or infection is initiated by changes on the surface of endothelial cells located in proximity to tissue damage. Inflammatory mediators, such as TNF-α, increase surface expression of adhesive ligands and receptors on the endothelial surface to which neutrophils tether and adhere. Neutrophils then transit through the activated endothelium to reach sites of tissue injury with little lasting vascular injury. However, in cases of sepsis, the interaction of endothelial cells with highly activated neutrophils can cause damage vascular damage. The identification of molecules that are essential for neutrophil diapedesis may reveal targets of therapeutic opportunity for preservation of endothelial function in the presence of critical illness. We tested the hypothesis that inhibition of neutrophil β1 integrin very late antigen-3 (VLA-3; α3β1) and/or inhibition of the tetraspanin (TM4) family member CD151 would protect against neutrophil-mediated loss of endothelial function. Methods: Blood was obtained from septic patients or healthy donors. Neutrophils were purified, and aliquots were treated with/without proinflammatory molecules. Confluent human umbilical vascular endothelial cells were activated with TNF-α. Electric cell impedance sensing was used to determine monolayer resistance over time after the addition of neutrophils that were treated with blocking antibodies against VLA-3 and/or CD151 or isotype controls. Groups (depending on relevancy) were analyzed by Mann-Whitney U test, Wilcoxon test, or repeated-measures one-way ANOVA. Results: Neutrophils from septic patients and neutrophils activated ex vivo reduced endothelial monolayer resistance to a greater extent than neutrophils from healthy donors. Antibody blockade of VLA-3 and/or CD151 significantly reduced activation-associated endothelial damage. Similar findings were demonstrated on fibronectin, collagen I, collagen IV, and laminin, suggesting that neutrophil surface VLA-3 and CD151 are responsible for endothelial damage regardless of substrata and are likely to be operative in all bodily tissues. Conclusion: This report identifies VLA-3 and CD151 on the activated human neutrophil, which are responsible for damage to endothelial function. Targeting these molecules in vivo may demonstrate preservation of organ function during critical illness., (Copyright © 2024 The Author(s). Published by Wolters Kluwer Health, Inc. on behalf of the Shock Society.)

Background: The tetraspanin family plays a pivotal role in the genesis of migrasomes, and Tetraspanin CD151 is also implicated in neovascularization within tumorous contexts. Nevertheless, research pertaining to the involvement of CD151 in hepatocellular carcinoma (HCC) neovascularization and its association with migrasomes remains inadequate., Methods: To investigate the correlation between CD151 and migrasome marker TSPAN4 in liver cancer, we conducted database analysis using clinical data from HCC patients. Expression levels of CD151 were assessed in HCC tissues and correlated with patient survival outcomes. In vitro experiments were performed using HCC cell lines to evaluate the impact of CD151 expression on migrasome formation and cellular invasiveness. Cell lines with altered CD151 expression levels were utilized to study migrasome generation and in vitro invasion capabilities. Additionally, migrasome function was explored through cellular aggregation assays and phagocytosis studies. Subsequent VEGF level analysis and tissue chip experiments further confirmed the role of CD151 in mediating migrasome involvement in angiogenesis and cellular signal transduction., Results: Our study revealed a significant correlation between CD151 expression and migrasome marker TSPAN4 in liver cancer, based on database analysis of clinical samples. High expression levels of CD151 were closely associated with poor survival outcomes in HCC patients. Experimentally, decreased CD151 expression led to reduced migrasome generation and diminished in vitro invasion capabilities, resulting in attenuated in vivo metastatic potential. Migrasomes were demonstrated to facilitate cellular aggregation and phagocytosis, thereby promoting cellular invasiveness. Furthermore, VEGF-enriched migrasomes were implicated in signaling and angiogenesis, accelerating HCC progression., Conclusions: In summary, our findings support the notion that elevated CD151 expression promotes migrasome formation, and migrasomes play a pivotal role in the invasiveness and angiogenesis of liver cancer cells, thereby facilitating HCC progression. This finding implies that migrasomes generated by elevated CD151 expression may constitute a promising high-priority target for anti-angiogenic therapy in HCC, offering crucial insights for the in-depth exploration of migrasome function and a renewed comprehension of the mechanism underlying liver cancer metastasis., (© 2024. The Author(s).)

Background: Tetraspanin CD151 is highly expressed in endothelia and reinforces cell adhesion, but its role in vascular inflammation remains largely unknown., Methods: In vitro molecular and cellular biological analyses on genetically modified endothelial cells, in vivo vascular biological analyses on genetically engineered mouse models, and in silico systems biology and bioinformatics analyses on CD151-related events., Results: Endothelial ablation of Cd151 leads to pulmonary and cardiac inflammation, severe sepsis, and perilous COVID-19, and endothelial CD151 becomes downregulated in inflammation. Mechanistically, CD151 restrains endothelial release of proinflammatory molecules for less leukocyte infiltration. At the subcellular level, CD151 determines the integrity of multivesicular bodies/lysosomes and confines the production of exosomes that carry cytokines such as ANGPT2 (angiopoietin-2) and proteases such as cathepsin-D. At the molecular level, CD151 docks VCP (valosin-containing protein)/p97, which controls protein quality via mediating deubiquitination for proteolytic degradation, onto endolysosomes to facilitate VCP/p97 function. At the endolysosome membrane, CD151 links VCP/p97 to (1) IFITM3 (interferon-induced transmembrane protein 3), which regulates multivesicular body functions, to restrain IFITM3-mediated exosomal sorting, and (2) V-ATPase, which dictates endolysosome pH, to support functional assembly of V-ATPase., Conclusions: Distinct from its canonical function in strengthening cell adhesion at cell surface, CD151 maintains endolysosome function by sustaining VCP/p97-mediated protein unfolding and turnover. By supporting protein quality control and protein degradation, CD151 prevents proteins from (1) buildup in endolysosomes and (2) discharge through exosomes, to limit vascular inflammation. Also, our study conceptualizes that balance between degradation and discharge of proteins in endothelial cells determines vascular information. Thus, the IFITM3/V-ATPase-tetraspanin-VCP/p97 complexes on endolysosome, as a protein quality control and inflammation-inhibitory machinery, could be beneficial for therapeutic intervention against vascular inflammation., Competing Interests: Disclosures None.

Current differentiation protocols for human induced pluripotent stem cells (hiPSCs) produce heterogeneous cardiomyocytes (CMs). Although chamber-specific CM selection using cell surface antigens enhances biomedical applications, a cell surface marker that accurately distinguishes between hiPSC-derived atrial CMs (ACMs) and ventricular CMs (VCMs) has not yet been identified. We have developed an approach for obtaining functional hiPSC-ACMs and -VCMs based on CD151 expression. For ACM differentiation, we found that ACMs are enriched in the CD151 low population and that CD151 expression is correlated with the expression of Notch4 and its ligands. Furthermore, Notch signaling inhibition followed by selecting the CD151 low population during atrial differentiation leads to the highly efficient generation of ACMs as evidenced by gene expression and electrophysiology. In contrast, for VCM differentiation, VCMs exhibiting a ventricular-related gene signature and uniform action potentials are enriched in the CD151 high population. Our findings enable the production of high-quality ACMs and VCMs appropriate for hiPSC-derived chamber-specific disease models and other applications., (© 2024. The Author(s).)

Triple-negative breast cancer is high heterogeneous, aggressive, and metastatic with poor prognosis. Despite of advances in targeted therapies, TNBC has been reported to cause high morbidity and mortality. A rare subpopulation within the tumor microenvironment organized into a hierarchy of cancer stem cells is responsible for therapy resistance and tumor recurrence. Repurposing of antiviral drugs for cancer treatment is gaining momentum due to reduced cost, labour, and research time, but limited due to lack of prognostic, and predictive markers. The present study investigates proteomic profiling and ROC analysis to identify CD151 and ELAVL1 as potential therapy response markers for the antiviral drug 2-thio-6-azauridine (TAU) in resistant TNBC. The stemness of MDA-MB 231 and MDA-MD 468 adherent cells was enriched by culturing them under non-adherent and non-differentiation conditions. Then, CD151 + subpopulation was isolated and characterized for the enrichment of stemness. This study found that CD151 has overexpressed in stemness enriched subpopulations, and also showed CD44 high and CD24 low expression along with stem cell-related transcription factors octamer-binding transcription factor 4 (OCT4) and Sex determining Y-box 2 (SOX2). This study also found that TAU induced significant cytotoxicity and genotoxicity in the CD151 + TNBC subpopulation and inhibited their proliferation by inducing DNA damage, cell cycle arrest at the G 2 M phase, and apoptosis. Further, a proteomic profiling study showed that the expression of CD151 along with ELAVL1, an RNA-binding protein, was significantly reduced with TAU treatment. KM plotter showed correlation of CD151 and ELAVL1 gene expression with a poor prognosis of TNBC. ROC analysis predicted and validated CD151 and ELAVL1 as best therapy response marker for TAU in TNBC. These findings provide new insight into repurposing antiviral drug TAU for treatment of metastatic and drug resistant TNBC., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Inc. All rights reserved.)

CD151 is a transmembrane protein implicated in tumor progression and has been shown to regulate various cellular and molecular mechanisms contributing to malignancy. More recently, the role of CD151 in the tumor immune microenvironment (TIME) has gained attention as a potential target for cancer therapy. This review aims to explore the role of CD151 in the TIME, focusing on the therapeutic and clinical perspectives. The role of CD151 in regulating the interactions between tumor cells and the immune system will be discussed, along with the current understanding of the molecular mechanisms underlying these interactions. The current state of the development of CD151-targeted therapies and the potential clinical applications of these therapies will also be reviewed. This review provides an overview of the current knowledge on the role of CD151 in the TIME and highlights the potential of CD151 as a therapeutic target for cancer treatment., Competing Interests: Declaration of Competing Interest Authors declare no conflict of interest., (Copyright © 2023 Elsevier B.V. All rights reserved.)

Despite clinical advances, ischemia-induced cardiac diseases remain an underlying cause of death worldwide. Epigenetic modifications, especially alterations in the acetylation of histone proteins play a pivotal role in counteracting stressful conditions, including ischemia. In our study, we found that histone active mark H3K27ac was significantly reduced and histone repressive mark H3K27me3 was significantly upregulated in the cardiomyocytes exposed to the ischemic condition. Then, we performed a high throughput drug screening assay using rat ventricular cardiomyocytes during the ischemic condition and screened an antioxidant compound library comprising of 84 drugs for H3K27ac by fluorescence microscopy. Our data revealed that most of the phenolic compounds like eugenol, apigenin, resveratrol, bis-demethoxy curcumin, D-gamma-tocopherol, ambroxol, and non-phenolic compounds like l-Ergothioneine, ciclopirox ethanolamine, and Tanshinone IIA have a crucial role in maintaining the cellular H3K27ac histone marks during the ischemic condition. Further, we tested the role of eugenol on cellular protection during ischemia. Our study shows that ischemia significantly reduces cellular viability and increases total reactive oxygen species (ROS), and mitochondrial ROS in the cells. Interestingly, eugenol treatment significantly restores the cellular acetylation at H3K27, decreases cellular ROS, and improves cellular viability. To explore the mechanism of eugenol-medicated inhibition of deacetylation, we performed a RNAseq experiment. Analysis of transcriptome data using IPA indicated that eugenol regulates several cellular functions associated with cardiovascular diseases, and metabolic processes. Further, we found that eugenol regulates the expression of HMGN1, CD151 and Ppp2ca genes during ischemia. Furthermore, we found that eugenol might protect the cells from ischemia through modulation of HMGN1 protein expression, which plays an active role in regulation of histone acetylation and cellular protection during stress. Thus, our study indicated that eugenol can be exploited as an agent to protect the ischemic cells and also could be used to develop a novel drug for treating cardiac disease., (Published by Elsevier Inc.)

Junctional adhesion molecule (JAM)-A is a cell adhesion receptor localized at epithelial cell-cell contacts with enrichment at the tight junctions. Its role during cell-cell contact formation and epithelial barrier formation has intensively been studied. In contrast, its role during collective cell migration is largely unexplored. Here, we show that JAM-A regulates collective cell migration of polarized epithelial cells. Depletion of JAM-A in MDCK cells enhances the motility of singly migrating cells but reduces cell motility of cells embedded in a collective by impairing the dynamics of cryptic lamellipodia formation. This activity of JAM-A is observed in cells grown on laminin and collagen-I but not on fibronectin or vitronectin. Accordingly, we find that JAM-A exists in a complex with the laminin- and collagen-I-binding α3β1 integrin. We also find that JAM-A interacts with tetraspanins CD151 and CD9, which both interact with α3β1 integrin and regulate α3β1 integrin activity in different contexts. Mapping experiments indicate that JAM-A associates with α3β1 integrin and tetraspanins CD151 and CD9 through its extracellular domain. Similar to depletion of JAM-A, depletion of either α3β1 integrin or tetraspanins CD151 and CD9 in MDCK cells slows down collective cell migration. Our findings suggest that JAM-A exists with α3β1 integrin and tetraspanins CD151 and CD9 in a functional complex to regulate collective cell migration of polarized epithelial cells., (© 2022. The Author(s).)

Small extracellular vesicles (sEVs) play a key role in intercellular communication. Cargo molecules carried by sEVs may affect the phenotype and function of recipient cells. Epithelial cancer cell-derived sEVs, particularly those enriched in CD151 or tetraspanin8 (TSPAN8) and associated integrins, promote tumour progression. The mechanism of binding and modulation of sEVs to recipient cells remains elusive. Here, we used genetically engineered breast cancer cells to derive TSPAN8-enriched sEVs and evaluated the impact of TSPAN8 on target cell membrane's diffusion and transport properties. The single-particle tracking technique showed that TSPAN8 significantly promoted sEV binding via confined diffusion. Functional assays indicated that the transgenic TSPAN8-sEV cargo increased cancer cell motility and epithelial-mesenchymal transition (EMT). In vivo, transgenic TSPAN8-sEV promoted uptake of sEVs in the liver, lung, and spleen. We concluded that TSPAN8 encourages the sEV-target cell interaction via forced confined diffusion and significantly increases cell motility. Therefore, TSPAN8-sEV may serve as an important direct or indirect therapeutic target., (© 2021 The Authors. Journal of Extracellular Vesicles published by Wiley Periodicals, LLC on behalf of the International Society for Extracellular Vesicles.)

To investigate the changes of circular (circ)RNA circCD151 expression in lung cancer tissues and cells and its effects on proliferation, migration and invasion of lung cancer cells. The relative expression levels of circCD151 in lung cancer tissues and lung cancer cells (A549 and NCI‑H292) were determined by reverse transcription‑quantitative PCR. The effects of silencing or upregulation of circCD151 on the activity and clonal forming ability of A549 and NCI‑H292 cells were detected by CCK‑8 and cloning formation experiments. Transwell invasion assay detected the effects of silencing or upregulation of circCD151 on the migration and invasion ability of A549 and NCI‑H292 cells. The regulatory effect of circCD151 on miR‑30d‑5p was detected by dual luciferase reporter gene. The relative expression level of circCD151 in lung cancer tissues was significantly higher compared with that in adjacent tissues. The relative expression level of circCD151 in A549 and NCI‑H292 cells was significantly higher compared with that in human lung epithelial cells. In A549 and NCI‑H292 cells, silencing circCD151 decreased cell activity and clonal formation ability and invasion ability was also significantly decreased. circCD151 was upregulated in A549 and NCI‑H292 cells and the activity and clonal formation ability of A549 and NCI‑H292 cells were significantly increased and the invasion ability was also significantly increased. Double luciferase reporter assay confirmed the ceRNA regulatory mechanism of circCD151/miR‑30d‑5p/GLI2. In the present study, in vivo and in vitro functional studies demonstrated that circCD151 may promote the proliferation, invasion and cell stemness of lung cancer cells. Further molecular mechanism studies demonstrated that circCD151 could promote the malignant proliferation of lung adenocarcinoma by targeting miR‑30d‑5p and upregulating GLI2 expression. From the perspective of circRNA, the present study will provide new clues to the pathogenesis and prognostic judgment of lung adenocarcinoma and provide a new target for clinical treatment.

Breast cancer is the most common and highly heterogeneous disease in women worldwide. Given the challenges in the treatment of advanced metastatic breast cancer, it is necessary to understand the molecular mechanisms related to disease progression. Exosomes play various roles in the progression of tumors, including promoting the invasion and advancing the distant metastasis. To study the molecular mechanisms related to the progression of luminal androgen receptor (LAR) breast cancer, we first isolated exosomes of MDA-MB-453 cells, a representative cell line of LAR. Through quantitative proteomic analysis, we identified 180 proteins specifically enriched in exosomes after comparing with those in cells, microvesicles, and the 150K supernatant. Among these, CD151, a protein involved in the regulation of cell motility was the most enriched one. CD151-knockdown exosomes reduced the invasion ability of the recipient breast cancer cell and lowered the phosphorylation level of tyrosine-protein kinase Lck, indicating that the invasion of LAR breast cancer may be due to CD151-enriched exosomes. Our work reports for the first time that CD151 was highly abundant in the exosomes of MDA-MB-453 cells and expands the understanding of the development process of LAR subtype, suggesting CD151 may be a potential candidate for the treatment of LAR breast cancer., Competing Interests: Declaration of competing interest The authors declare that they have no competing interests., (Copyright © 2021 Elsevier B.V. and Société Française de Biochimie et Biologie Moléculaire (SFBBM). All rights reserved.)

Background: Tetraspanins CD151, a transmembrane 4 superfamily protein, has been identified participating in the initiation of a variety of cancers. However, the precise function of CD151 in non-small cell lung cancer (NSCLC) remains unclear. Here, we addressed the pro-tumoral role of CD151 in NSCLC by targeting EGFR/ErbB2 which favors tumor proliferation, migration and invasion., Methods: First, the mRNA expression levels of CD151 in NSCLC tissues and cell lines were measured by RT-PCR. Meanwhile, CD151 and its associated proteins were analyzed by western blotting. The expression levels of CD151 in NSCLC samples and its paired adjacent lung tissues were then verified by Immunohistochemistry. The protein interactions are evaluated by co-immunoprecipitation. Flow cytometry was applied to cell cycle analysis. CCK-8, EdU Incorporation, and clonogenic assays were used to analyze cell viability. Wound healing, transwell migration, and matrigel invasion assays were utilized to assess the motility of tumor cells. To investigate the role of CD151 in vivo, lung carcinoma xenograft mouse model was applied., Results: High CD151 expression was identified in NSCLC tissues and cell lines, and its high expression was significantly associated with poor prognosis of NSCLC patients. Further, knockdown of CD151 in vitro inhibited tumor proliferation, migration, and invasion. Besides, inoculation of nude mice with CD151-overexpressing tumor cells exhibited substantial tumor proliferation compared to that in control mice which inoculated with vector-transfected tumor cells. Noteworthy, we found that overexpression of CD151 conferred cell migration and invasion by interacting with integrins. We next sought to demonstrate that CD151 regulated downstream signaling pathways via activation of EGFR/ErbB2 in NSCLC cells. Therefore, we infer that CD151 probably affects the sensitivity of NSCLC in response to anti-cancer drugs., Conclusions: Based on these results, we demonstrated a new mechanism of CD151-mediated tumor progression by targeting EGFR/ErbB2 signaling pathway, by which CD151 promotes NSCLC proliferation, migration, and invasion, which may considered as a potential target of NSCLC treatment.

Background: Translational failures in anti-adhesion molecule therapies after stroke reveal the necessity of developing new strategies that not only interrupt leukocyte recruitment but also consider the inhibition of endothelial cell inflammation, verification of therapeutic time window, and normal function maintenance of circulating leukocytes. Our study focused on the potential therapeutic value of CD151 downregulation in improving current anti-adhesion molecule therapies., Methods: Lentivirus intracerebroventricular administration was conducted to inhibit the CD151 expression and observe its functional influence on neurological injuries and outcomes. Then, immunohistochemistry and myeloperoxidase activity assessment were performed to explore the effects of CD151 expression on neutrophil and monocyte recruitment after rat cerebral ischemia. Primary rat brain microvascular endothelial cells were subjected to oxygen glucose deprivation and reoxygenation to elucidate the underlying working mechanisms between CD151 and VCAM-1., Results: The CD151 downregulation remarkably reduced neurological injuries and improved neurological outcomes, which were accompanied with reduced neutrophil and monocyte infiltration after the CD151 downregulation. The VCAM-1 expression was remarkably decreased among the adhesion molecules on the endothelial cell responsible for neutrophil and monocyte infiltration. The activation of p38 MAPK and NF-κB pathways was restricted after the CD151 downregulation. p38 MAPK and NF-κB inhibitors decreased the VCAM-1 expression, and p38 acted as an upstream regulator of NF-κB. However, CD151 downregulation did not directly influence the neutrophil and monocyte activation., Conclusions: Overall, CD151 regulated the expression of adhesion molecules. It also played a critical role in suppressing VCAM-1-mediated neutrophil and monocyte infiltration via the p38/NF-κB pathway. This study possibly provided a new basis for improving current anti-adhesion molecule therapies.

Integrin α3β1 plays a crucial role in tumor formation in the two-stage chemical carcinogenesis model (DMBA and TPA treatment). However, the mechanisms whereby the expression of α3β1 influences key oncogenic drivers of this established model are not known yet. Using an in vivo mouse model with epidermal deletion of α3β1 and in vitro Matrigel cultures of transformed keratinocytes, we demonstrate the central role of α3β1 in promoting the activation of several protumorigenic signaling pathways during the initiation of DMBA/TPA‒driven tumorigenesis. In transformed keratinocytes, α3β1-mediated focal adhesion kinase/Src activation leads to in vitro growth of spheroids and to strong Akt and STAT 3 activation when the α3β1-binding partner tetraspanin CD151 is present to stabilize cell‒cell adhesion and promote Smad2 phosphorylation. Remarkably, α3β1 and CD151 can support Akt and STAT 3 activity independently of α3β1 ligation by laminin-332 and as such control the essential survival signals required for suprabasal keratin-10 expression during keratinocyte differentiation. These data demonstrate that α3β1 together with CD151 regulate the signaling pathways that control the survival of differentiating keratinocytes and provide a mechanistic understanding of the essential role of α3β1 in early stages of skin cancer development., (Copyright © 2021 The Authors. Published by Elsevier Inc. All rights reserved.)

Objective: The aim of the study was to develop a model for predicting cancer risk in colorectal polyps' patients (CPPs), as well as to reveal additional prognosis factors for Stage III colorectal cancer based on differences in subpopulations of tetraspanins, tetraspanin-associated and tetraspanin-non-associated proteases in blood plasma exosomes of CPPs and colorectal cancer patients (CRCPs)., Methods: The subpopulations of CD151- and Tspan8-positive exosomes, the subpopulations of metalloproteinase at the surface of СD9-positive exosomes and the level of 20S proteasomes in plasma exosomes in 15 CPPs (tubulovillous adenomas) and 60 CRCPs were evaluated using flow cytometry and Western blotting. Logistic regression analysis was performed to predict cancer risk of CPPs., Results: The levels of 20S proteasomes in exosomes, MMP9+, MMP9+/MMP2+/EMMPRIN+ in CD9-positive blood plasma exosomes are associated with the risk of malignant transformation of colorectal tubulovillous adenomas.  In patients with Stage III CRC, the levels of 20S proteasomes (less than 2 units) and MMP9+ subpopulations (more than 61%) in plasma exosomes are unfavorable prognostic factors for overall survival. The levels of 20S proteasomes and ADAM10+/ADAM17- subpopulations in CD9-positive blood plasma exosomes are the most significant values for predicting relapse-free survival., Conclusion: Protease cargo in CD9-positive blood plasma exosomes is prognostic biomarker for colorectal polyps and colorectal cancer.

Preeclampsia (PE) is a pregnancy-related syndrome characterized by new-onset hypertension and proteinuria after gestational 20 weeks. Oxidative stress, resulting from the imbalance between the production of oxidants and antioxidants in placentas, is recognized as a key pathology of PE. To date, the molecules that regulate antioxidants production remain unclear. CD151, a member of tetraspanins, is an important regulator of many physiological functions. However, the function of CD151 in oxidative stress and its association with pregnancy-related complications are currently unknown. In the present study, we have demonstrated that CD151 was a key regulator of antioxidants in placentas. Compared with the placentas of the controls, the placentas of PE patients exhibited decreased CD151 expression accompanying with decreased antioxidant gene expression (HO-1, NQO-1, GCLC and SOD-1). In vitro, overexpression of CD151 in trophoblast cells could enhance HO-1, NQO-1, GCLC and SOD-1 expression but downregulation of CD151 decreased those antioxidant genes expression, which indicates CD151 is the upstream of antioxidants. Importantly, the phenotype of PE (hypertension and proteinuria) was mimicked in the downregulating CD151 induced mouse model. Moreover, the beneficial effect of CD151 in trophoblast cells was hindered when ERK and Nrf2 signaling were blocked. Overall, our results revealed CD151 might be a new target for PE treatment., (Copyright © 2021 The Author(s). Published by Elsevier Inc. All rights reserved.)

CD151 impacts various signaling pathways in different cancers, and promotes colorectal cancer (CRC) cell malignancy by yet undefined mechanisms. This study aimed to comprehensively assess CD151's function in CRC. CD151 levels were significantly higher in CRC tissues and cells compared with controls in the tissue microarray. Cell viability, migration and invasion were suppressed by CD151 downregulation in CRC cells. Consistently, mouse xenografts were inhibited by CD151 silencing. RNA-seq revealed that multiple genes were significantly altered by CD151 knockdown in cultured CRC cells and xenografts. Particularly, transforming growth factor β1 (TGFβ1), carcinoembryonic antigen-related cell adhesion molecule 6 (CEACAM6) and leucine-rich repeat-containing G-protein coupled receptor 5 (LGR5) alongside CD151 were downregulated both in vitro and in vivo . Co-immunoprecipitation and mass spectrometry results were validated by qRT-PCR and immunoblot. Moreover, pull-down assay and immunofluorescence confirmed the associations of TGFβ1, CEACAM6 and LGR5 with CD151. This study demonstrated CEACAM6, LGR5 and Wnt pathway suppression by CD151 silencing might occur through TGFβ1 regulation, offering a comprehensive view of CD151's roles in colorectal carcinogenesis. Our findings provide an insight into the CD151-involved signaling network in CRC oncogenesis, which could be utilized to design novel targeted therapies against CD151-based signaling in treatment for CRC., Competing Interests: Competing Interests: The authors have declared that no competing interest exists., (© The author(s).)

The prevalence of chronic kidney disease is increasing globally; however, effective therapeutic options are limited. In this study, we aimed to identify urinary miRNAs reflecting the effect of therapeutic intervention in rats with comorbid hypertension and diabetes. Additionally, the potential beneficial effects of anti-platelet sarpogrelate and cilostazol were investigated. Nephropathy progression in streptozotocin (STZ)-treated spontaneously hypertensive rats (SHRs), including albuminuria, collagen deposition, and histopathological changes, was alleviated by sarpogrelate and antihypertensive agent telmisartan. Global analysis of urinary miRNAs identified that miR-199a-3p was commonly reduced by sarpogrelate and telmisartan treatment. In vitro analysis suggested CD151 as a target gene of miR-199a-3p: miR-199a-3p overexpression repressed CD151 levels and miR-199a-3p interacted with the 3'-untranslated region of the CD151 gene. In addition, we demonstrated that the miR-199a-3p/CD151 axis is associated with the transforming growth factor-β1 (TGF-β1)-induced fibrogenic pathway. TGF-β1 treatment led to miR-199a-3p elevation and CD151 suppression, and miR-199a-3p overexpression or CD151-silencing enhanced TGF-β1-inducible collagen IV and α-smooth muscle actin (α-SMA) levels. In vivo analysis showed that the decrease in CD151 and the increase in collagen IV and α-SMA in the kidney from STZ-treated SHR were restored by sarpogrelate and telmisartan administration. In an additional animal experiment using cilostazol and telmisartan, there was a correlation between urinary miR-199a-3p reduction and the ameliorating effects of cilostazol or combination with telmisartan. Collectively, these results indicate that urinary miR-199a-3p might be utilized as a marker for nephropathy treatment. We also provide evidence of the benefits of antiplatelet sarpogrelate and cilostazol in nephropathy progression., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Triple-negative breast cancer (TNBC) is an aggressive subtype of breast cancer. Patients with TNBC have poor overall survival because of limited molecular therapeutic targets. Recently, exosomes have been recognized as key mediators in cancer progression, but the molecular components and function of TNBC-derived exosomes remain unknown. The main goal of this study was to reveal the proteomic landscape of serum exosomes derived from ten patients with TNBC and 17 healthy donors to identify potential therapeutic targets. Using a tandem mass tag-based quantitative proteomics approach, we characterized the proteomes of individual patient-derived serum exosomes, identified exosomal protein signatures specific to patients with TNBC, and filtered out differentially expressed proteins. Most importantly, we found that the tetraspanin CD151 expression levels in TNBC-derived serum exosomes were significantly higher than those exosomes from healthy subjects, and we validated our findings with samples from 16 additional donors. Furthermore, utilizing quantitative proteomics approach to reveal the proteomes of CD151-deleted exosomes and cells, we found that exosomal CD151 facilitated secretion of ribosomal proteins via exosomes while inhibiting exosome secretion of complement proteins. Moreover, we proved that CD151-deleted exosomes significantly decreased the migration and invasion of TNBC cells. This is the first comparative study of the proteomes of TNBC patient-derived and CD151-deleted exosomes. Our findings indicate that profiling of TNBC-derived exosomal proteins is a useful tool to extend our understanding of TNBC, and exosomal CD151 may be a potential therapeutic target for TNBC., Competing Interests: Conflict of interest The authors declare no competing interests., (Copyright © 2021 The Authors. Published by Elsevier Inc. All rights reserved.)

Preservation of the blood-brain barrier (BBB) function is a potential protective strategy against cerebral ischemic injuries. CD151 has a beneficial effect in maintaining vascular stability and plays a role in pro-angiogenesis. Both vascular stability and angiogenesis can affect BBB function. Therefore, we aimed to examine the action of CD151 in regulating BBB permeability after cerebral ischemic injury in the present study. Using a transient focal cerebral ischemia (tFCI) rat model, we established that CD151 overexpression in the brain mitigated the leakage of endogenous IgG at 6-24 h after tFCI in vivo. Moreover, we found that CD151 can decrease the diffusion of macromolecules through monolayer brain microvessel endothelial cells (BMVECs) after glucose and oxygen deprivation (OGD)-reoxygenation in vitro. Furthermore, overexpression of CD151 in BMVECs suppressed OGD-reoxygenation-induced F-actin formation and RhoA activity. However, while preserving BBB integrity after tFCI, CD151 overexpression did not affect the post-stroke outcomes. Taken together, the present study demonstrated that CD151 overexpression in the brain protects BBB permeability at early phase after tFCI. CD151 may be a potential target for early BBB protection in ischemic stroke.

Tetraspanin CD151 was found to be upregulated in malignant cell types and has been identified as a tumor metastasis promoter. In this study, we aimed to examine the role of the CD151-integrin complex in lung cancer metastasis and the underlying mechanisms. CD151 QRD 194-196 →AAA 194-196 mutant was generated and used to transfect A549 human lung adenocarcinoma cells. We found that there was no significant difference in CD151 protein expression between CD151 and CD151-AAA mutant groups. In vitro, CD151-AAA mutant delivery abrogated the migration and invasion of A549 cells, which was promoted by CD151 gene transfer. Furthermore, CD151-AAA delivery failed to activate FAK and p130Cas signaling pathways. Western blot and immunohistochemical staining showed strong CD151 expression in lung cancerous tissues but not in adjacent normal tissues. Increased level of CD151 protein was observed in 20 of the patients and the positive rate of CD151 protein in specimens was 62.5% (20/32). In addition, CD151 was co-localized with α3 integrin at the cell-cell contact site in carcinoma tissues. These results suggested that the disruption of the CD151-α3 integrin complex may impair the metastasis-promoting effects and signaling events induced by CD151 in lung cancer. Our findings identified a key role for CD151-α3 integrin complex as a promoter in the lung cancer.

Endothelial microparticles (EMPs) are involved in various cardiovascular pathologies and play remarkable roles in communication between endothelial cells (ECs), which are constantly exposed to mechanical cyclic stretch (CS) following blood pressure. However, the roles of EMPs induced by CS in EC homeostasis are still unclear. Both fluorescence resonance energy transfer (FRET) and western blotting revealed the activation of Src in ECs was significantly increased by 5% CS-induced EMPs. Furthermore, proteomic analysis revealed that the contents were obvious different in the EMPs between 5%- and 15%-group. Based on the bioinformatic analysis, CD151 on EMPs was predicted to activate Src, which was further confirmed by both FRET and western blotting. Moreover, the expression of CD151 on EMPs was significantly increased by 5% CS and involved in the binding of EMPs to ECs. EC apoptosis, which was significantly decreased by 5% CS-derived EMPs, showed obvious increase after pretreatment with Src inhibitor in target ECs. Our present research suggests that mechanical stretch changes the components of EMPs, which in turn modulates EC apoptosis by Src activation. CD151 expressed on CS-induced EMPs may play important roles in EC communication and homeostasis., (© 2020 Federation of American Societies for Experimental Biology.)

Tetraspanins are a family of proteins with an array of functions that are well studied in cancer biology, but their importance in immunology is underappreciated. Here we establish the tetraspanin CD151 as a unique marker of T-cell activation and, in extension, an indicator of elevated, systemic T-cell activity. Baseline CD151 expression found on a subset of T-cells was indicative of increased activation of the MAPK pathway. Following TCR/CD3 activation, CD151 expression was upregulated on the overall T-cell population, a quintessential feature of an activation marker. CD151+ T-cell frequencies in the spleen, an organ with increased immune activity, were twice as high as in paired peripheral blood samples. This CD151+ T-cell frequency increase was not paralleled by an increase of CD25 or CD38, demonstrating that CD151 expression is regulated independently of other T-cell activation markers. CD151+ T-cells were also more likely to express preformed granzyme B, suggesting that CD151+ T cells are pro-inflammatory. To this end, HIV-1 patients on antiretroviral therapy who are reported to exhibit chronically elevated levels of immune activity, had significantly higher CD4+CD151+ T-cell frequencies than healthy controls, raising the possibility that proinflammatory CD151+ T cells could contribute to the premature immunological aging phenotype observed in these patients.

The integrin α6β4 and cytoskeletal adaptor plectin are essential components of type I and type II hemidesmosomes (HDs). We recently identified an alternative type II HD adhesion complex that also contains CD151 and the integrin α3β1. Here, we have taken a BioID proximity labeling approach to define the proximity protein environment for α6β4 in keratinocytes. We identified 37 proteins that interacted with both α6 and β4, while 20 and 78 proteins specifically interacted with the α6 and β4 subunits, respectively. Many of the proximity interactors of α6β4 are components of focal adhesions (FAs) and the cortical microtubule stabilizing complex (CMSC). Though the close association of CMSCs with α6β4 in HDs was confirmed by immunofluorescence analysis, CMSCs have no role in the assembly of HDs. Analysis of the β4 interactome in the presence or absence of CD151 revealed that they are strikingly similar; only 11 different interactors were identified. One of these was the integrin α3β1, which interacted with α6β4 more strongly in the presence of CD151 than in its absence. These findings indicate that CD151 does not significantly contribute to the interactome of α6β4, but suggest a role of CD151 in linking α3β1 and α6β4 together in tetraspanin adhesion structures., Competing Interests: Competing interestsThe authors declare no competing or financial interests., (© 2020. Published by The Company of Biologists Ltd.)

Endometrial cancer, a type of primary epithelial malignant tumor in the endometrium, is one of the three most common malignant tumors of the female reproductive system. While the incidence of endometrial cancer has been recently rising, its etiology remains unclear. In this study we found that EM2D9, an independently developed monoclonal antibody, specifically recognized endometrial cancer cells; we further determined that EM2D9 target protein was α5β1. In vitro and in vivo experiments showed that EM2D9 inhibited the migration of endometrial cancer cells. Real-time quantitative PCR results showed that the expression of CD151 mRNA in endometrial carcinoma cells significantly decreased after EM2D9 treatment. We also found that EM2D9 affected the FAK signaling pathway. Collectively, these results shed light on a new mechanism for the development of endometrial carcinoma., Competing Interests: Declaration of competing interest The authors declare that they have no competing interests., (Copyright © 2020 Elsevier B.V. All rights reserved.)

The immune microenvironment in inflammatory breast cancer (IBC) is poorly characterised, and molecular and cellular pathways that control accumulation of various immune cells in IBC tissues remain largely unknown. Here, we discovered a novel pathway linking the expression of the tetraspanin protein CD151 in tumour cells with increased accumulation of macrophages in cancerous tissues. It is notable that elevated expression of CD151 and a higher number of tumour-infiltrating macrophages correlated with better patient responses to chemotherapy. Accordingly, CD151-expressing IBC xenografts were characterised by the increased infiltration of macrophages. In vitro migration experiments demonstrated that CD151 stimulates the chemoattractive potential of IBC cells for monocytes via mechanisms involving midkine (a heparin-binding growth factor), integrin α6β1, and production of extracellular vesicles (EVs). Profiling of chemokines secreted by IBC cells demonstrated that CD151 increases production of midkine. Purified midkine specifically stimulated migration of monocytes, but not other immune cells. Further experiments demonstrated that the chemoattractive potential of IBC-derived EVs is blocked by anti-midkine antibodies. These results demonstrate for the first time that changes in the expression of a tetraspanin protein by tumour cells can affect the formation of the immune microenvironment by modulating recruitment of effector cells to cancerous tissues. Therefore, a CD151-midkine pathway can be considered as a novel target for controlled changes of the immune landscape in IBC. © 2020 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd., (© 2020 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.)

During cell invasion, human papillomaviruses use large CD151 patches on the cell surface. Here, we studied whether these patches are defined architectures with features for virus binding and/or internalization. Super-resolution microscopy reveals that the patches are assemblies of closely associated nanoclusters of CD151, integrin α3 and integrin α6. Integrin α6 is required for virus attachment and integrin α3 for endocytosis. We propose that CD151 organizes viral entry platforms with different types of integrin clusters for different functionalities. Since numerous viruses use tetraspanin patches, we speculate that this building principle is a blueprint for cell-surface architectures utilized by viral particles.

The physiological importance of CD151 tetraspanin is known from somatic cells and its outside-in signalling through integrins was described. In male germ cells, two tetraspanins, CD9 and CD81, are involved in sperm-egg membrane fusion, and similarly to integrins, they occupy characteristic regions. We report here on a newly discovered presence of CD151 in sperm, and present its expression and distribution during spermatogenesis and sperm transition during the acrosome reaction. We traced CD151 gene and protein expression in testicular cell subpopulations, with strong enrichment in spermatogonia and spermatids. The testicular and epididymal localization pattern is designated to the sperm head primary fusion site called the equatorial segment and when compared to the acrosome vesicle status, CD151 was located into the inner acrosomal membrane overlying the nucleus. Moreover, we show CD151 interaction with α6 integrin subunit, which forms a dimer with β4 as a part of cis-protein interactions within sperm prior to gamete fusion. We used mammalian species with distinct sperm morphology and sperm maturation such as mouse and bull and compared the results with human. In conclusion, the delivered findings characterise CD151 as a novel sperm tetraspanin network member and provide knowledge on its physiology in male germ cells.

Membrane-bound proteases play a key role in biology by degrading matrix proteins or shedding adhesion receptors. MT1-MMP metalloproteinase is critical during cancer invasion, angiogenesis, and development. MT1-MMP activity is strictly regulated by internalization, recycling, autoprocessing but also through its incorporation into tetraspanin-enriched microdomains (TEMs), into invadopodia, or by its secretion on extracellular vesicles (EVs). We identified a juxtamembrane positively charged cluster responsible for the interaction of MT1-MMP with ERM (ezrin/radixin/moesin) cytoskeletal connectors in breast carcinoma cells. Linkage to ERMs regulates MT1-MMP subcellular distribution and internalization, but not its incorporation into extracellular vesicles. MT1-MMP association to ERMs and insertion into TEMs are independent phenomena, so that mutation of the ERM-binding motif in the cytoplasmic region of MT1-MMP does not preclude its association with the tetraspanin CD151, but impairs the accumulation and coalescence of CD151/MT1-MMP complexes at actin-rich structures. Conversely, gene deletion of CD151 does not impact on MT1-MMP colocalization with ERM molecules. At the plasma membrane MT1-MMP autoprocessing is severely dependent on ERM association and seems to be the dominant regulator of the enzyme collagenolytic activity. This newly characterized MT1-MMP/ERM association can thus be of relevance for tumor cell invasion., Competing Interests: The authors declare no conflict of interest.

Cyclo (L-Leucyl-L-Prolyl) peptide/CLP is a marine natural metabolite and well recognized as an antimicrobial and antioxidant agent with limited studies on anticancer activity. The current study aims to determine the effect of CLP on migration and growth of triple negative breast cancer cell lines. The anti-growth potential was evaluated by MTT, BrdU and TUNEL assays; DNA damage by γH2AX and Dead green assays; antimigration activity by Boyden chamber invasion and wound healing assays. Interaction of CLP with CD151 was resolved by PatchDock. Effect of CLP on the expression of transmembrane CD151 was evaluated by cell-based ELISA assay. The interaction between CD151 and EGFR was predicted by using FireDoc Web server. Impact of CLP on the interaction of CD151 with EGFR was evaluated by co-immunoprecipitation assay. The effect of CLP on the cell cycle and its controlling proteins was determined by Western blotting. CLP reduced the viability of MDA-MB-231 and MDA-MB-468 TNBC cell lines but not human breast healthy epithelial cell line (MCF-12A) similar to eribulin, standard. CLP also inhibited proliferation; cell cycle and migration. It induced DNA strand breaks, DNA damage, and cell death. It showed the most favorable interactions with CD151 in in silico docking and significantly reduced the expression of membrane-bound CD151 proteins. FireDoc Web study predicted the association between CD151 and EGFR with -29.13 kcal/mol of binding energy. CLP reduced the interaction of CD151 with EGFR along with the expression of cyclin D, CDK4, PAK, RAC1, and P27kiP1. This study concludes that CLP suppresses growth and migration by attenuating cell cycle of TNBC cell lines via EGFR and CD151 signaling. Thus, exploring the EGFR and CD151 signaling pathway targeted by CLP may provide a new approach in the treatment of TNBC., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2019 Elsevier B.V. All rights reserved.)

CD151 is an abundantly expressed eukaryotic transmembrane protein on the cell surface. It is involved in cell adhesion, angiogenesis and signal transduction as well in disease conditions such as cancer and viral infections. However, the molecular mechanism of CD151 activation is poorly understood due to the lack of structural information. By considering the difficulties in expressing the membrane protein in E. coli, herein we introduce the strategic design for the effective expression of recombinant CD151 protein in E. coli with high yield, that would aid for the structural studies. CD151 having four transmembrane domain (TMD's) along with small and a large extracellular loop (LEL) is constructed in parts to enhance the soluble expression of the protein attached with fusion tag. This has led to the high yield of the recombinant CD151 protein in the designed constructs. The recombinant CD151 protein is characterized and confirmed by western blot, CD and Mass peptide fingerprint. The molecular dynamics simulations (MDS) for the full-length CD151 shows conformational changes in the LEL of the protein in the presence and absence of cholesterol and indicate the certainty of closed and open conformation of CD151 based on cholesterol binding. The MDS results have led to the understanding of the possible underlying mechanism for the activation of the CD151 protein.

Tetraspanin CD151 has been suggested to regulate cell adhesion through its association with laminin-binding integrins α3β1 and α6β4; however, its precise function in keratinocyte adhesion remains elusive. In this study, we investigated the role of CD151 in the formation and maintenance of laminin-associated adhesions. We show that CD151, through binding to integrin α3β1, plays a critical role in the stabilization of an adhesion structure with a distinct molecular composition of hemidesmosomes with tetraspanin features. These hybrid cell-matrix adhesions, which are formed early during cell adhesion and spreading and at later stages of cell spreading, are present in the central region of the cells. They contain the CD151-α3β1/α6β4 integrin complexes and the cytoskeletal linker protein plectin, but are not anchored to the keratin filaments. In contrast, hemidesmosomes, keratin filament-associated adhesions that contain integrin α6β4, plectin, BP180 (encoded by COL17A1 ) and BP230 (encoded by DST ), do not require CD151 for their formation or maintenance. These findings provide new insights into the dynamic and complex regulation of adhesion structures in keratinocytes and the pathogenic mechanisms underlying skin blistering diseases caused by mutations in the gene for CD151., Competing Interests: Competing interestsThe authors declare no competing or financial interests., (© 2019. Published by The Company of Biologists Ltd.)

CD151/Tspan24 (SFS-1, PETA3) is one of the best characterized members of the tetraspanin family, whose involvement in breast cancer (BCa) progression was demonstrated both in vitro and in vivo. We have recently reported that in ErbB2-overexpressing BCa cells grown in 3D laminin-rich extracellular matrix, CD151 regulated basal phosphorylation and homodimerization of ErbB2 and sensitized the cells to Herceptin (trastuzumab). Following from these data, we have here analyzed an involvement of CD151 in regulation of ErbB2/ErbB3 heterodimerization and its impact on cell response to Herceptin. CD151 was found to: (1) impair ErbB2/ErbB3 heterodimerization, (2) inhibit heregulin-dependent cell growth in 3D and signaling, and (3) counteract the protective effect of heregulin on Herceptin-mediated growth inhibition. Analysis of tissue samples demonstrated for the first time clinical significance of CD151 in patients with ErbB2-overexpressing BCa undergone trastuzumab-based therapy. Consistent with in vitro results, CD151 impact on disease outcome was ErbB3-dependent. In patients with ErbB3-negative tumors, CD151 significantly improved both overall survival (OS) (hazard ratio [HR] = 0.19, P = 0.034) and progression-free survival (PFS) (HR = 0.36, P = 0.043), while in ErbB3-positive cases it had no significant effect on patient survival (OS: HR = 3.33, P = 0.283; PFS: HR = 2.40, P = 0.208). These results support previous findings and show that CD151 acts as an important component of ErbB2 signaling axis in BCa cells, affecting their sensitivity to ErbB2-targeting therapy., (Copyright © 2018 Elsevier Inc. All rights reserved.)

Tetraspanin protein CD151 has typically been studied as binding partner and functional regulator of laminin-binding integrins. However, we show here that CD151 supports anti-cancer drug resistance independent of integrins. CD151 ablation sensitized multiple tumor cell types to several anti-cancer drugs (e.g., gefitinib and camptothecin), thus increasing apoptosis, as seen using cleaved caspase-3, cleaved PARP (poly (ADP-ribose) polymerase), annexin V, and propidium iodide staining assays. Drug sensitization due to CD151 ablation is integrin-independent, because, (1) effects occurred in cells when integrins were unengaged with ligand, (2) integrin ablation (α3 and α6 subunits) did not mimic effects of CD151 ablation, (3) the CD151 QRD mutant, with diminished integrin association, and CD151 WT (unmutated CD151) similarly reconstituted drug protection, and (4) treatment with anti-cancer drugs selectively upregulated intracellular nonintegrin-associated CD151 (NIA-CD151), consistent with its role in drug resistance. Together, these results suggest that upregulated CD151 expression may support not only typical integrin-dependent functions, but also integrin-independent survival of circulating (and possibly metastatic) cancer cells during anti-cancer drug therapy.

Human skin is morphologically and physiologically different from the skin of other primates. However, the genetic causes underlying human-specific skin characteristics remain unclear. Here, we quantitatively demonstrate that the epidermis and dermis of human skin are significantly thicker than those of three Old World monkey species. In addition, we indicate that the topography of the epidermal basement membrane zone shows a rete ridge in humans but is flat in the Old World monkey species examined. Subsequently, we comprehensively compared gene expression levels between human and nonhuman great ape skin using next-generation cDNA sequencing (RNA-Seq). We identified four structural protein genes associated with the epidermal basement membrane zone or elastic fibers in the dermis (COL18A1, LAMB2, CD151, and BGN) that were expressed significantly greater in humans than in nonhuman great apes, suggesting that these differences may be related to the rete ridge and rich elastic fibers present in human skin. The rete ridge may enhance the strength of adhesion between the epidermis and dermis in skin. This ridge, along with a thick epidermis and rich elastic fibers might contribute to the physical strength of human skin with a low amount of hair. To estimate transcriptional regulatory regions for COL18A1, LAMB2, CD151, and BGN, we examined conserved noncoding regions with histone modifications that can activate transcription in skin cells. Human-specific substitutions in these regions, especially those located in binding sites of transcription factors which function in skin, may alter the gene expression patterns and give rise to the human-specific adaptive skin characteristics., (© The Author(s) 2019. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.)

Wilms'tumor is the most common malignant tumor with a poor clinical prognosis because of metastasis or recurrence among children worldwide. CD151, a member of transmembrane 4 superfamily, has now been confirmed to be involved in tumor progression including the proliferation, migration, invasion and metastasis of tumor cells. GSK-3β/P21/cyclinD signaling pathway plays a critical role in the cell cycle progression, regulating cellular proliferation. In this study, CD151 protein and mRNA levels were examined by western blot and RT-PCR. The proliferation of SK-NEP-1 cells was examined by CCK8 assay and the migration of SK-NEP-1 cells was detected with wound healing assay. Furthermore, p-GSK3β protein, GSK3β protein, p21protein and CyclinD protein were examined by western blot to verify whether CD151 could regulate the Wilms'tumor progression via the GSK-3β/P21/cyclinD signaling pathway. The RT-PCR and western blot results showed that CD151 protein was upregulated in Wilms'tumor cells compared with the control. The results by CCK8 assay and wound healing assay demonstrated that CD151 overexpression promoted the proliferation and migration in SK-NEP-1 cells and CD151 interference showed the opposite effects. Western blot assay revealed that CD151 activated the GSK-3β/P21/cyclinD signaling pathway and upregulated the expression of p-GSK3β protein, p21protein and CyclinD protein. It was also verified that CD151 promotes proliferation and migration of SK-NEP-1 cells through the GSK-3β/P21/cyclinD signaling pathway in this study. The specific aim of the study is to investigate and verify the role of CD151 in Wilm's tumor. Therefore, in-depth study on the molecular mechanisms will provide new strategies and methods for the treatment of Wilm's tumor., (Copyright © 2018. Published by Elsevier GmbH.)

Objective: This study aimed to explore the expression characteristics of CD151 in breast cancer (BC) and to further study its role in the development of BC and potential regulatory mechanisms., Patients and Methods: Quantitative Real-Time Polymerase Chain Reaction (qRT-PCR) was used to detect the level of CD151 in 82 pairs of BC tissues and adjacent normal ones, and the relationship between CD151 expression and BC pathological parameters and prognosis was analyzed. CD151 expression in BC cells was further validated using qRT-PCR. The CD151 knockdown model was constructed in BC cell lines including MCF-7 and SKBR3 using the small interference RNA. The cell counting kit-8 (CCK-8) and transwell assay were used to analyze the effect of CD151 on the biological function of BC cells, and finally Western blot was performed to explore its underlying mechanism., Results: QRT-PCR analysis revealed that CD151 level in BC tissues was strikingly higher than that in normal ones, and the difference was statistically significant. Compared with patients with low CD151 level, patients with high CD151 level had worse tumor stage, lymph node metastasis, and distant metastases. The higher the incidence of metastasis, the lower the overall survival rate. Compared with the negative control group, the ability of cell proliferation or invasion and migration in the CD151 knockdown group was significantly reduced. In addition, Western blot results demonstrated that the levels of proteins in TGF-β1/Smad pathway, including transforming growth factor-β1 (TGF-β1), p-Smad2, p-Smad3, N-cad, Vimentin and MMP-9, were remarkably decreased in cells of si-CD151 group., Conclusions: The expression of CD151 in BC was significantly increased, which was found evidently associated with BC stage, lymph node or distant metastasis, and poor prognosis. Meanwhile, CD151 may promote the proliferation and invasion of BC by regulating TGF-β1/Smad pathway.

Expression of the tetraspanin CD151 is frequently upregulated in epithelial malignancies and correlates with poor prognosis. Here, we report that CD151 is involved in regulation of the expression of fibroblast growth factor receptor 2 (FGFR2). Depletion of CD151 in breast cancer cells resulted in an increased level of FGFR2. Accordingly, an inverse correlation between CD151 and FGFR2 was observed in breast cancer tissues. CD151-dependent regulation of the FGFR2 expression relies on post-transcriptional mechanisms involving HuR (also known as ELAVL1), a multifunctional RNA-binding protein, and the assembly of processing bodies (P-bodies). Depletion of CD151 correlated with inhibition of PKC, a well-established downstream target of CD151. Accordingly, the levels of dialcylglycerol species were decreased in CD151-negative cells, and inhibition of PKC resulted in the increased expression of FGFR2. Whereas expression of FGFR2 itself did not correlate with any of the clinicopathological data, we found that FGFR2 - /CD151 + patients were more likely to have developed lymph node metastasis. Conversely, FGFR2 - /CD151 - patients demonstrated better overall survival. These results illustrate functional interdependency between CD151 complexes and FGFR2, and suggest a previously unsuspected role of CD151 in breast tumorigenesis., Competing Interests: Competing interestsThe authors declare no competing or financial interests., (© 2018. Published by The Company of Biologists Ltd.)

The nucleotide degrading enzyme gene RNASEH2A (ribonuclease H2 subunit A) has been found to be overexpressed in cancers. Our aim was to understand the role of RNASEH2A in cancer prognostication and to establish a scoring system based on the expressions of genes interacting with RNASEH2A. We screened the nucleotide degrading enzyme gene expression in RNAseq data of 14 cancer types derived from The Cancer Genome Atlas (TCGA) and found that RNASEH2A overexpression was associated with poor patient survival only in renal cell carcinomas (RCCs). Further cluster analyses of samples with poor outcomes revealed that cluster of differentiation 151 ( CD151 ) upregulation correlated with low cyclin dependent kinase 1 ( CDK1 ) and high RNASEH2A expression. The combination of low CD151 expression and high RNASEH2A expression resulted in impaired proliferation in four kidney cancer cell lines, suggesting potential synthetic dosage lethality (SDL) interactions between the two genes. A prognostication scoring system was established based on the expression levels of RNASEH2A- , CDK1- , and CD151- related genes, which could effectively predict the overall survival in a TCGA clear cell RCC cohort ( n = 533, 995.3 versus 2242.2 days, p < 0.0001), in another clear cell renal cell carcinoma (ccRCC) cohort E-GEOD-22541 ( n = 44, 390.0 versus 1889.2 days, p = 0.0007), and in a TCGA papillary RCC (pRCC) cohort ( n = 287, 741.6 versus 1623.7 days, p < 0.0001). Our results provide a clinically applicable prognostication scoring system for renal cancers.

Background: Despite advances in our understanding of the mechanisms of influenza A virus (IAV) infection, the crucial virus-host interactions during the viral replication cycle still remain incomplete. Tetraspanin CD151 is highly expressed in the human respiratory tract, but its pathological role in IAV infection is unknown., Objectives: We sought to characterize the functional role and mechanisms of action of CD151 in IAV infection of the upper and lower respiratory tracts with H1N1 and H3N2 strains., Methods: We used CD151-null mice in an in vivo model of IAV infection and clinical donor samples of in vitro-differentiated human nasal epithelial cells cultured at air-liquid interface., Results: As compared with wild-type infected mice, CD151-null infected mice exhibited a significant reduction in virus titer and improvement in survival that is associated with pronounced host antiviral response and inflammasome activation together with accelerated lung repair. Interestingly, we show that CD151 complexes newly synthesized viral proteins with host nuclear export proteins and stabilizes microtubule complexes, which are key processes necessary for the polarized trafficking of viral progeny to the host plasma membrane for assembly., Conclusions: Our results provide new mechanistic insights into our understanding of IAV infection. We show that CD151 is a critical novel host factor of nuclear export signaling whereby the IAV nuclear export uses it to complement its own nuclear export proteins (a site not targeted by current therapy), making this regulation unique, and holds promise for the development of novel alternative/complementary strategies to reduce IAV severity., (Copyright © 2017 American Academy of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.)

Epidermolysis bullosa (EB) is caused by mutations in as many as 19 distinct genes. We have developed a next-generation sequencing (NGS) panel targeting genes known to be mutated in skin fragility disorders, including tetraspanin CD151 expressed in keratinocytes at the dermal-epidermal junction. The NGS panel was applied to a cohort of 92 consanguineous families of unknown subtype of EB. In one family, a homozygous donor splice site mutation in CD151 (NM&#95;139029; c.351+2T>C) at the exon 5/intron 5 border was identified, and RT-PCR and whole transcriptome analysis by RNA-seq confirmed deletion of the entire exon 5 encoding 25 amino acids. Immunofluorescence of proband's skin and Western blot of skin proteins with a monoclonal antibody revealed complete absence of CD151. Transmission electron microscopy showed intracellular disruption and cell-cell dysadhesion of keratinocytes in the lower epidermis. Clinical examination of the 33-year old proband, initially diagnosed as Kindler syndrome, revealed widespread blistering, particularly on pretibial areas, poikiloderma, nail dystrophy, loss of teeth, early onset alopecia, and esophageal webbing and strictures. The patient also had history of nephropathy with proteinuria. Collectively, the results suggest that biallelic loss-of-function mutations in CD151 underlie an autosomal recessive mechano-bullous disease with systemic features. Thus, CD151 should be considered as the 20th causative, EB-associated gene., (Copyright © 2017 Elsevier B.V. All rights reserved.)

Environmental surveillance of porcine reproductive and respiratory syndrome virus (PRRSV) represents a key issue in control of the disease. CD151 has recently been recognized as one of several receptors for PRRSV. We describe here a novel method for concentration of PRRSV from the environmental samples by CD151-binding capture. After fusion to self-aggregating peptide ELK16, the large extracellular loop (LEL) of porcine CD151 and its two segments (namely N63 and C63) were expressed in E. coli as protein aggregates. The three fusion proteins were purified to high purities by regular centrifugation and washing with Triton X-100. Viral binding assay showed that the C63-ELK16 protein, but not ELK16-N63 protein, had the specific binding affinity for PRRSV. The C63-ELK16 protein could bind to, and eluted from, PRRSV in pH-, temperature-, and time-dependent manners with a final virus recovery of 44.7%. By using PRRSV-spiked and experimentally infected pig fecal slurry samples, the C63-ELK16 binding capture-combined quantitative RT-PCR was shown to have higher detection sensitivity than the conventional RT-PCR. Although the viral RNA could be detected in the experimentally infected pig samples with or without C63-ELK16 binding capture, infectious PRRSV was not isolated without C63-ELK16 binding capture. Therefore, the CD151-binding capture method established offers sufficient recovery and quickness and will facilitate environmental PRRSV surveillance.

Background: PVT1 was up-regulated in patients with gastric cancer (GC) and might be as a novel biomarker for predicting GC. However, the exact mechanism of PVT1 exerting functions in GC was still poorly understood. Emerging evidence suggests that long noncoding RNAs may act as endogenous microRNA (miRNA) sponges to bind to miRNAs and regulate their function., Aim: This study aimed to determine the function of PVT1 on miR-152 expression in GC cells., Methods: The levels of PVT1 and miR-152 were determined in GC tissues by quantitative real-time PCR. The expression of miR-152 was detected in GC cells transfected with PVT1 plasmid or siPVT1. Luciferase assay was performed to verify the regulation of miR-152 to CD151 or FGF2 expression and PVT1 to miR-152 expression. The effects of PVT1 on the expression of CD151 and FGF2 were evaluated by Western blot., Results: PVT1 was up-regulated in GC tissues than that in the matched normal tissues, and mRNA level of miR-152 was decreased. MiR-152 was negatively associated with PVT1 expression in GC tissues. Based on the in silico analysis, we found that PVT1 have three binding sequences for miR-152. Moreover, PVT1 might inhibit the expression of miR-152 and increased the expression of CD151 and FGF2 through regulating miR-152. PVT1 was positively associated with CD151 and FGF2 expression in GC tissues., Conclusions: PVT1 might act as a "sponge" to inhibit miR-152 in gastric cancer cells. PVT1 is a promising molecular target to improve the diagnosis and therapy of GC.

CD151, a member of the tetraspanin family of receptors, is a lateral organizer and modulator of activity of several families of transmembrane proteins. It has been implicated in the development and progression of several cancers, but its role in chronic inflammatory disease is less well understood. Here we show that CD151 is upregulated by distinct microenvironmental signals in a range of chronic inflammatory liver diseases and in primary liver cancer, in which it supports lymphocyte recruitment. CD151 was highly expressed in endothelial cells of the hepatic sinusoids and neovessels developing in fibrotic septa and tumor margins. Primary cultures of human hepatic sinusoidal endothelial cells (HSECs) expressed CD151 at the cell membrane and in intracellular vesicles. CD151 was upregulated by VEGF and HepG2 conditioned media but not by proinflammatory cytokines. Confocal microscopy confirmed that CD151 colocalized with the endothelial adhesion molecule/immunoglobulin superfamily member, VCAM-1. Functional flow-based adhesion assays with primary human lymphocytes and HSECs demonstrated a 40% reduction of lymphocyte adhesion with CD151 blockade. Inhibition of lymphocyte adhesion was similar between VCAM-1 blockade and a combination of CD151/VCAM-1 blockade, suggesting a collaborative role between the two receptors. These studies demonstrate that CD151 is upregulated within the liver during chronic inflammation, where it supports lymphocyte recruitment via liver endothelium. We propose that CD151 regulates the activity of VCAM-1 during lymphocyte recruitment to the human liver and could be a novel anti-inflammatory target in chronic liver disease and hepatocellular cancer prevention. NEW & NOTEWORTHY Chronic hepatitis is characterized by lymphocyte accumulation in liver tissue, which drives fibrosis and carcinogenesis. Here, we demonstrate for the first time that the tetraspanin CD151 supports lymphocyte adhesion to liver endothelium. We show that CD151 is upregulated in chronic liver disease and hepatocellular carcinoma (HCC) and is regulated on endothelium by tissue remodeling and procarcinogenic factors. These regulatory and functional studies identify CD151 as a potential therapeutic target to treat liver fibrosis and HCC., (Copyright © 2017 the American Physiological Society.)

The human tetraspanin family of scaffold proteins comprises 33 isoforms. Being integral membrane proteins, they organize a so-called tetraspanin web via homomeric and heteromeric protein-protein interactions with integrins, immunoglobulins, growth factors, receptor tyrosine kinases, proteases, signaling proteins, and viral capsid proteins. Tetraspanins promote cellular effects, such as adhesion, migration, invasion, signaling, membrane fusion, protein trafficking, cancer progression, and infections. The ubiquitous expression of multiple tetraspanin isoforms and partner proteins hampers specific interaction studies. Here, we evaluated Dictyostelium discoideum as a non-mammalian expression system for human tetraspanins. Using high-content imaging we quantified tetraspanins in D. discoideum via fusion with green fluorescent protein. Three human tetraspanins, CD9, CD81, and CD151, served as test cases for which optimizations were carried out. We swapped the GFP domain between the N- and C-termini, added a Kozak sequence, and partially or fully adapted of the codon usage. This way, CD81 and CD151 were successfully produced. A conformation specific antibody further confirmed correct folding of CD81 and flow cytometry indicated an intracellular localization. Based on these data, we envision a D. discoideum-based co-expression platform with human partner proteins for studying tetraspanin interactions and their selective druggability on a large scale without the interference of endogenous human proteins., (Copyright © 2017 Elsevier Inc. All rights reserved.)

The ability of the parasite Plasmodium falciparum to evade the immune system and be sequestered within human small blood vessels is responsible for severe forms of malaria. The sequestration depends on the interaction between human endothelial receptors and P. falciparum erythrocyte membrane protein 1 (PfEMP1) exposed on the surface of the infected erythrocytes (IEs). In this study, the transcriptomes of parasite populations enriched for parasites that bind to human P-selectin, E-selectin, CD9 and CD151 receptors were analysed. IT4&#95;var02 and IT4&#95;var07 were specifically expressed in IT4 parasite populations enriched for P-selectin-binding parasites; eight var genes (IT4&#95;var02/07/09/13/17/41/44/64) were specifically expressed in isolate populations enriched for CD9-binding parasites. Interestingly, IT4 parasite populations enriched for E-selectin- and CD151-binding parasites showed identical expression profiles to those of a parasite population exposed to wild-type CHO-745 cells. The same phenomenon was observed for the 3D7 isolate population enriched for binding to P-selectin, E-selectin, CD9 and CD151. This implies that the corresponding ligands for these receptors have either weak binding capacity or do not exist on the IE surface. Conclusively, this work expanded our understanding of P. falciparum adhesive interactions, through the identification of var transcripts that are enriched within the selected parasite populations.

Objectives: CD151 is a plasma membrane protein belonging to the tetraspanin family. CD151 represents a putative therapeutic target and has been suggested as a prognostic marker in several cancer types. The present study aims to investigate the prognostic relevance of immunohistochemical CD151 expression in head and neck squamous cell carcinoma (HNSCC)., Materials and Methods: Tissue microarray (TMA) sections containing samples from 667 cancers of oral cavity, oro- and hypopharynx and larynx, for which follow-up data were available, were analyzed for CD151 expression by immunohistochemistry., Results: Membranous CD151 immunostaining was recorded in 269 (60.3 %) of 446 analyzable cases. Staining was considered weak in 129 (28.9 %), moderate in 98 (22.0 %), and strong in 42 (9.4 %) of cancers. CD151 expression was unrelated to histological grade, tumor stage, nodal status, or surgical margin. There was a tendency towards a somewhat lower prevalence of CD151 expression in tumors of the oral cavity (52.9 % positive) as compared to cancers of the oro-hypopharynx (62.1 %) and larynx (63.3 %; p = 0.0100). CD151 expression had no impact on patient survival., Clinical Relevance: In summary, immunohistochemical analysis of CD151 lacks prognostic utility in HNSCC. The high prevalence of CD151 expression in HNSCC emphasizes its putative relevance as a therapeutic target for further development of anti-CD151 drugs.

Members of the tetraspanin family have been identified as essential cellular membrane proteins in infectious diseases by nearly all types of pathogens. The present review highlights recently published data on the role of tetraspanin CD151, CD81, and CD63 and their interaction partners in host cell entry by human cytomegalo- and human papillomaviruses. Moreover, we discuss a model for tetraspanin assembly into trafficking platforms at the plasma membrane. These platforms might persist during intracellular viral trafficking., (© 2017 The Author(s); published by Portland Press Limited on behalf of the Biochemical Society.)