Search

Regulatory T cell (Treg) stability is necessary for the proper control of immune activity and tissue homeostasis. However, it remains unclear whether Treg stability must be continually reinforced or is established during development under physiological conditions. Foxp3 has been characterized as a central mediator of the genetic program that governs Treg stability. Here, we demonstrate that to maintain Foxp3 protein expression, Tregs require cell-to-cell contact, which is mediated by the CD147-CD98 interaction. As Tregs are produced, CD147, which is expressed on their surface, is stimulated by CD98, which is widely expressed in the physiological environment. As a result, CD147’s intracellular domain binds to CDK2 and retains it near the membrane, leading to Foxp3 dephosphorylation and the prevention of Foxp3 degradation. In addition, the optimal distribution of Foxp3+ Tregs under both pathological and physiological conditions depends on CD98 expression. Thus, our study provides direct evidence that Foxp3-dependent Treg stability is reinforced in the periphery by the interaction between CD147 and CD98 in the surrounding environment. More importantly, Tregs with high CD147 expression effectively inhibit inflammatory responses and maintain Foxp3 stability, which has guiding significance for the application of Tregs in immunotherapy.

The prosperity of the biotherapeutics market reflects the feasibility and effectiveness of therapeutic antibodies for the treatment of cancers, inflammatory disorders, and refractory infections. As drawbacks emerge in clinical trials and practice, such as impeded binding, reduced effector functions, and frequent adverse reactions, modifications of therapeutic antibodies are unprecedently burgeoning in research and development (R&D). These modifications include: ① modified glycosylation; ② fragment of crystallizable domain (Fc) amino acid alterations; ③ cross-isotype or cross-subclass exchanges; ④ antibody–drug conjugates (ADCs); ⑤ single chain of variable region fragment (scFv) for chimeric antigen receptor T (CAR-T) cells; and ⑥ bispecific antibodies (bsAbs) in order to promote binding affinity, half-life in circulation, effectiveness toward target cells and, ultimately, to achieve overall improved efficacy. While many achievements have been made around the world in the past decades, China has been playing an active role in this realm, with its great demand for biotherapeutics with R&D potential. This review recapitulates the international progress that has been achieved with modified therapeutic antibodies, and then focuses on that of China in an independent section.

Sepsis is a life‐threatening organ dysfunction syndrome, and liver is a susceptible target organ in sepsis, because the activation of inflammatory pathways contributes to septic liver injury. Oxidative stress has been documented to participate in septic liver injury, because it not only directly induces oxidative genotoxicity, but also exacerbates inflammatory pathways to potentiate damage of liver. Therefore, to ameliorate oxidative stress is promising for protecting liver in sepsis. Wogonin is the compound extracted from the medicinal plant Scutellaria baicalensis Geogi and was found to exert therapeutic effects in multiple inflammatory diseases via alleviation of oxidative stress. However, whether wogonin is able to mitigate septic liver injury remains unknown. Herein, we firstly proved that wogonin treatment could improve survival of mice with lipopolysaccharide (LPS)‐ or caecal ligation and puncture (CLP)‐induced sepsis, together with restoration of reduced body temperature and respiratory rate, and suppression of several pro‐inflammatory cytokines in circulation. Then, we found that wogonin effectively alleviated liver injury via potentiation of the anti‐oxidative capacity. To be specific, wogonin activated Nrf2 thereby promoting expressions of anti‐oxidative enzymes including NQO‐1, GST, HO‐1, SOD1 and SOD2 in hepatocytes. Moreover, wogonin‐induced Nrf2 activation could suppress NF‐κB‐regulated up‐regulation of pro‐inflammatory cytokines. Ultimately, we provided in vivo evidence that wogonin activated Nrf2 signalling, potentiated anti‐oxidative enzymes and inhibited NF‐κB‐regulated pro‐inflammatory signalling. Taken together, this study demonstrates that wogonin can be the potential therapeutic agent for alleviating liver injury in sepsis by simultaneously ameliorating oxidative stress and inflammatory response through the activation of Nrf2.

Negative regulation of antitumor T-cell-immune responses facilitates tumor-immune escape. Here, we show that deletion of CD147, a type I transmembrane molecule, in T cells, strongly limits in vivo tumor growth of mouse melanoma and lung cancer in a CD8+ T-cell-dependent manner. In mouse tumor models, CD147 expression was upregulated on CD8+ tumor-infiltrating lymphocytes (TILs), and CD147 was coexpressed with two immune-checkpoint molecules, Tim-3 and PD-1. Mining publicly available gene-profiling data for CD8+ TILs in tumor biopsies from metastatic melanoma patients showed a higher level of CD147 expression in exhausted CD8+ TILs than in other subsets of CD8+ TILs, along with expression of PD-1 and TIM-3. Additionally, CD147 deletion increased the abundance of TILs, cytotoxic effector function of CD8+ T cells, and frequency of PD-1+ CD8+ TILs, and partly reversed the dysfunctional status of PD-1+Tim-3+CD8+ TILs. The cytotoxic transcription factors Runx3 and T-bet mediation enhanced antitumor responses by CD147-/- CD8+ T cells. Moreover, CD147 deletion in T cells increased the frequency of TRM-like cells and the expression of the T-cell chemokines CXCL9 and CXCL10 in the tumor microenvironment. Analysis of tumor tissue samples from patients with non-small-cell lung cancer showed negative correlations between CD147 expression on CD8+ TILs and the abundance of CD8+ TILs, histological grade of the tumor tissue samples, and survival of patients with advanced tumors. Altogether, we found a novel function of CD147 as a negative regulator of antitumor responses mediated by CD8+ TILs and identified CD147 as a potential target for cancer immunotherapy.

Thymic involution during aging is a major cause of decreased T-cell production and reduced immunity. Here, we show that the loss of CD147 on T cells prevents thymic senescence, resulting in slowed shrinkage of the thymus with age and increased production of naive T cells. This phenotype is the result of slowing of the epithelial–mesenchymal transition (EMT) process in thymic epithelial cells (TECs), which eventually leads to reduced adipocyte accumulation. In an in vitro coculture system, we found that TGFβ is an important factor in the EMT process in TECs and that it can reduce the expression of E-cadherin through p-Smad2/FoxC2 signaling. Moreover, CD147 on T cells can accelerate the decline in E-cadherin expression by interacting with Annexin A2 on TECs. In the presence of TGFβ, Annexin A2 and E-cadherin colocalize on TECs. However, CD147 on T cells competitively binds to Annexin A2 on TECs, leading to the isolation of E-cadherin. Then, the isolated E-cadherin is easily phosphorylated by phosphorylated Src kinase, the phosphorylation of which was induced by TGFβ, and finally, p-E-cadherin is degraded. Thus, in the thymus, the interaction between T cells and TECs contributes to thymic involution with age. In this study, we illuminate the mechanism underlying the triggering of the EMT process in TECs and show that inhibiting TGFβ and/or CD147 may serve as a strategy to hinder age-related thymic involution.

SARS-CoV-2 mutations contribute to increased viral transmissibility and immune escape, compromising the effectiveness of existing vaccines and neutralizing antibodies. An in-depth investigation on COVID-19 pathogenesis is urgently needed to develop a strategy against SARS-CoV-2 variants. Here, we identified CD147 as a universal receptor for SARS-CoV-2 and its variants. Meanwhile, Meplazeumab, a humanized anti-CD147 antibody, could block cellular entry of SARS-CoV-2 and its variants—alpha, beta, gamma, and delta, with inhibition rates of 68.7, 75.7, 52.1, 52.1, and 62.3% at 60 μg/ml, respectively. Furthermore, humanized CD147 transgenic mice were susceptible to SARS-CoV-2 and its two variants, alpha and beta. When infected, these mice developed exudative alveolar pneumonia, featured by immune responses involving alveoli-infiltrated macrophages, neutrophils, and lymphocytes and activation of IL-17 signaling pathway. Mechanistically, we proposed that severe COVID-19-related cytokine storm is induced by a “spike protein-CD147-CyPA signaling axis”: Infection of SARS-CoV-2 through CD147 initiated the JAK-STAT pathway, which further induced expression of cyclophilin A (CyPA); CyPA reciprocally bound to CD147 and triggered MAPK pathway. Consequently, the MAPK pathway regulated the expression of cytokines and chemokines, which promoted the development of cytokine storm. Importantly, Meplazumab could effectively inhibit viral entry and inflammation caused by SARS-CoV-2 and its variants. Therefore, our findings provided a new perspective for severe COVID-19-related pathogenesis. Furthermore, the validated universal receptor for SARS-CoV-2 and its variants can be targeted for COVID-19 treatment.

Major gaps in understanding the molecular mechanisms of colorectal cancer (CRC) progression and intestinal mucosal repair have hampered therapeutic development for gastrointestinal disorders. Trefoil factor 3 (TFF3) has been reported to be involved in CRC progression and intestinal mucosal repair; however, how TFF3 drives tumors to become more aggressive or metastatic and how TFF3 promotes intestinal mucosal repair are still poorly understood. Here, we found that the upregulated TFF3 in CRC predicted a worse overall survival rate. TFF3 deficiency impaired mucosal restitution and adenocarcinogenesis. CD147, a membrane protein, was identified as a binding partner for TFF3. Via binding to CD147, TFF3 enhanced CD147-CD44s interaction, resulting in signal transducer and activator of transcription 3 (STAT3) activation and prostaglandin G/H synthase 2 (PTGS2) expression, which were indispensable for TFF3-induced migration, proliferation, and invasion. PTGS2-derived PGE2 bound to prostaglandin E2 receptor EP4 subtype (PTGER4) and contributed to TFF3-stimulated CRC progression. Solution NMR studies of the TFF3-CD147 interaction revealed the key residues critical for TFF3 binding and the induction of PTGS2 expression. The ability of TFF3 to enhance mucosal restitution was weakened by a PTGS2 inhibitor. Blockade of TFF3-CD147 signaling using competitive inhibitory antibodies or a PTGS2 inhibitor reduced CRC lung metastasis in mice. Our findings bring strong evidence that CD147 is a novel receptor for TFF3 and PTGS2 signaling is critical for TFF3-induced mucosal restitution and CRC progression, which widens and deepens the understanding of the molecular function of trefoil factors.

The γ-secretase complex is a presenilin-dependent aspartyl protease involved in the intramembranous cleavage of various type I transmembrane proteins. As a type I transmembrane protein, CD147 is highly expressed in hepatoma cells and promotes cell proliferation, migration, and invasion. However, the direct underlying mechanism of how CD147 promotes cancer cell proliferation is unknown. Here, we demonstrated that CD147 undergoes an intramembranous cleavage by the γ-secretase at lysine 231 to release its intracellular domains (ICDs). The nuclear translocation of the CD147ICD regulated Notch1 expression by directly binding to the NOTCH1 promoter and promoted the activation of the Notch signaling pathway. Simultaneously, overexpression of CD147ICD promoted cancer cell proliferation via Notch1 signaling. In 102 cases of human hepatocellular carcinoma (HCC) tissues, patients with a high positive rate of nuclear CD147ICD expression had a significantly poor overall survival compared with patients with a low positive rate of nuclear CD147ICD expression. We confirmed that nuclear CD147ICD predicted a poor prognosis in human HCC. The combined therapy of the γ-secretase complex inhibitor and CD147-directed antibody showed better efficacy than monotherapy in orthotopic transplantation HCC mouse models. In conclusion, CD147 is cleaved by the γ-secretase and releases CD147ICD to the cell nucleus, promoting Notch1 expression via direct binding to the NOTCH1 promoter. © 2019 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Background Ankylosing spondylitis (AS) is a chronic inflammatory disease with worldwide high prevalence. Although AS is strongly associated with HLA-B27 MHC-I antigen presentation, the role played by αβ T cells in AS remains elusive. Methods Utilizing TCRβ repertoire sequencing and bioinformatics tools developed in house, we analyzed overall TCR repertoire structures and antigen-recognizing CDR3 motifs in AS patients with different disease activities. Findings We found that disease progression is associated with both CD4+ and CD8+ T cell oligo-clonal expansion, which suggests that αβ T cell activation may mediate AS disease progression. By developing a bioinformatics platform to dissect antigen-specific responses, we discovered a cell population consisting of both CD4+ and CD8+ T cells expressing identical TCRs, herein termed CD4/8 T cells. CD4/8 clonotypes were highly enriched in the spondyloarthritic joint fluid of patients, and their expansion correlated with the activity of disease. Interpretation These results provide evidence on the T cell clone side to reveal the potential role of CD4/8 T cells in the etiology of AS development.

Receptor-interacting protein kinase 3 (RIP3) is the core regulator that switches cell death from apoptosis to necrosis. However, its role in tumor immunity is unknown. In this study, decreased RIP3 expression was observed in patients with hepatocellular carcinoma (HCC), which correlates with myeloid-derived suppressor cell (MDSC) accumulation. Moreover, RIP3 is a prognosis factor for patients with HCC. We further found that RIP3 knockdown results in an increase of MDSCs and a decrease of interferon gamma-positive (IFN-γ+ ) cluster of differentiation 8-positive (CD8+ ) tumor-infiltrating lymphocytes (IFN-γ+ CD8+ T cells) in hepatoma tissues, thus promoting immune escape and HCC growth in immunocompetent mice. By phosphorylating P65Ser536 and promoting phosphorylated P65Ser536 nuclear translocation, RIP3 knockdown increases the expression of chemokine (C-X-C motif) ligand 1 (CXCL1) in HCC cells. RIP3 knockdown induces MDSC recruitment through the CXCL1-chemokine (C-X-C motif) receptor 2 (CXCR2) axis. Furthermore, a CXCR2 antagonist substantially suppresses MDSC chemotaxis and HCC growth in RIP3 knockout mice. Conclusion: RIP3 deficiency is an essential factor directing MDSC homing to HCC and promoting CXCL1/CXCR2-induced MDSC chemotaxis to facilitate HCC immune escape and HCC progression; blocking the CXCL1-CXCR2 chemokine axis may provide an immunological therapeutic approach to suppress progression of RIP3 deficiency HCC.

Cluster of differentiation 147 (CD147), a transmembrane protein of the immunoglobulin superfamily, is a potential target of treatment against human non-small cell lung cancer (NSCLC). Although there have been exciting advances in epidermal growth factor receptor (EGFR)-targeted therapy for NSCLC in recent years, additional novel targeted agents are needed to improve the efficiency and to offer more options for patients. Antibody-drug conjugates (ADCs) utilize a chemical linker to conjugate cytotoxic drugs to a monoclonal antibody to maximize the delivery to target cells and minimize the delivery to other normal cells. The aim of this study was to prepare a novel anti-CD147 conjugate and examine the tumoricidal effect on NSCLC in vitro and in vivo. HcHAb18 was conjugated to the drug maytansinoid 1 (DM1) via a non-cleavable thioether linker (SMCC) to prepare HcHAb18-DM1 with an appropriate drug-antibody ratio (DAR). NSCLC cell lines expressing different levels of CD147 were tested in vitro to determine internalization, cell cycle arrest and cytotoxicity. In vivo efficacy and safety of HcHAb18-DM1 were evaluated in NSCLC xenograft mouse models. We found that HcHAb18-DM1 displayed an impressive potency in vitro and in vivo with a favorable safety profile. Upon binding to CD147, HcHAb18 could be internalized and delivered the payload DM1 to disturb mitotic spindle formation by microtubules. Target cells were arrested at G2/M phase and HcHAb18-DM1 exerted antiproliferative activity in vitro. Antigen-antibody binding and target cells with high growth rate were two integral prerequisites for exerting anti-tumor activity of HcHAb18-DM1. Therefore, we suggest HcHAb18-DM1 is a promising CD147-targeted therapeutic for NSCLC.

CD147 is a tumor-associated antigen that plays a key regulatory role in tumor invasion and distant metastasis. However, the exact role of CD147 phosphorylation, which is deregulated during cancer progression, is unknown. Here, the effects of CD147 phosphorylation on the malignant behavior of hepatocellular carcinoma (HCC) cells and its possible underlying mechanisms are explored. An in situ Duolink-proximity ligation assay (PLA) was used to detect CD147 phosphorylation. Tandem mass spectrometry was employed to identify the phosphorylation sites of CD147. The effects of CD147 phosphorylation on the malignant behavior of HCC cells were evaluated using scratch wound healing assays, transwell invasion assays and cell cycle assays. The genes regulated by CD147 phosphorylation were detected by RNA sequencing. We identified phosphorylated serine-246 in the C terminus of CD147 in primary HCC tissues, whereas serine to alanine substitution mutation analysis suggested that CD147 is phosphorylated mainly at serine-252 in HCC-derived Huh-7 cells. Recovery expression of S246A/S252A mutants in CD147 knockout cells revealed significantly increased migration and invasion capacities compared to wildtype CD147 expressing cells. Cyclophilin A (CyPA) treatment decreased the phosphorylation level of CD147, whereas NIMA-related kinase 6 (NEK6) increased the CD147 phosphorylation level. Moreover, the CD147 phosphorylation level was found to be dramatically decreased in HCC tissues in patients with distant metastases, and a low phosphorylation level of CD147 was found to be associated with a high serum AFP level, recurrence and a poor overall survival. From our data we conclude that hypo-phosphorylated CD147 promotes the migration and invasion of HCC cells and correlates with an unfavorable prognosis in HCC patients, indicating that targeting the aberrantly hypo-phosphorylated form of CD147 may be instrumental for the development of novel therapeutic modalities directed against HCC metastasis.

While immunotherapy has achieved unprecedented success in conquering cancer, the majority of patients develop primary or acquired resistance to immunotherapy, largely in part due to the complicated metabolic networks in the tumor microenvironment. The microenvironmental metabolic networks are woven by a set of metabolic checkpoints, and accumulating evidence indicates that these metabolic checkpoints orchestrate antitumor immunity and immunotherapy. Metabolic checkpoints can regulate T cell development, differentiation and function, orchestrate metabolic competition between tumor cells and infiltrating T cells, and respond to the metabolic stress imposed on the infiltrating T cells. Furthermore, metabolic checkpoints and pathways can modulate the expression profiles of immune checkpoint receptors and ligands and vice versa. Therefore, repurposing interventions targeting metabolic checkpoints might synergize with immunotherapy, and promising approaches to reprogram the metabolic environment are much more warranted. In this review, we summarize recent researches on the metabolic checkpoints and discuss how these metabolic checkpoints regulate antitumor immunity and the promising approaches to modulate these metabolic checkpoints in the combination therapy. A comprehensive and objective understanding of the metabolic checkpoints might help the research and development of novel approaches to antitumor immunotherapy.

SARS-CoV-2 and its variants are raging worldwide. Unfortunately, the global vaccination is not efficient enough to attain a vaccine-based herd-immunity and yet no special and effective drug is developed to contain the spread of the disease. Previously we have identified CD147 as a novel receptor for SARS-CoV-2 infection. Here, we demonstrated that CD147 antibody effectively inhibits infection and cytokine storm caused by SARS-CoV-2 variants. In CD147KO VeroE6 cells, infections of SARS-CoV-2, its variants (B.1.1.7, B.1.351) and pseudovirus mutants (B.1.1.7, B.1.351, B.1.525, B.1.526 (S477N), B.1.526 (E484K), P.1, P.2, B.1.617.1, B.1.617.2) were decreased. Meanwhile, CD147 antibody effectively blocked the entry of variants and pseudomutants in VeroE6 cells, and inhibited the expression of cytokines. A model of SARS-CoV-2-infected hCD147 transgenic mice was constructed, which recapitulated the features of exudative diffuse alveolar damage and dynamic immune responses of COVID-19. CD147 antibody could effectively clear the virus and alveolar exudation, resolving the pneumonia. We found the elevated level of cyclophilin A (CyPA) in plasma of severe/critical cases, and identified CyPA as the most important proinflammatory intermediate causing cytokine storm. Mechanistically, spike protein of SARS-CoV-2 bound to CD147 and initiated the JAK-STAT pathway, which induced expression of CyPA. CyPA reciprocally bound to CD147, triggered MAPK pathway and consequently mediated the expression of cytokine and chemokine. In conclusion, CD147 is a critical target for SARS-CoV-2 variants and CD147 antibody is a promising drug to control the new wave of COVID-19 epidemic.

Genomic sequencing analysis of tumors provides potential molecular therapeutic targets for precision medicine. However, identifying a key driver gene or mutation that can be used for hepatocellular carcinoma (HCC) treatment remains difficult. Here, we performed whole-exome sequencing on genomic DNA obtained from six pairs of HCC and adjacent tissues and identified two novel somatic mutations of UBE2S (p. Gly57Ala and p. Lys63Asn). Predictions of the functional effects of the mutations showed that two amino-acid substitutions were potentially deleterious. Further, we observed that wild-type UBE2S, especially in the nucleus, was significantly higher in HCC tissues than that in adjacent tissues and closely related to the clinicopathological features of patients with HCC. Functional assays revealed that overexpression of UBE2S promoted the proliferation, invasion, metastasis, and G1/S phase transition of HCC cells in vitro, and promoted the tumor growth significantly in vivo. Mechanistically, UBE2S interacted with TRIM28 in the nucleus, both together enhanced the ubiquitination of p27 to facilitate its degradation and cell cycle progression. Most importantly, the small-molecule cephalomannine was found by a luciferase-based sensitive high-throughput screen (HTS) to inhibit UBE2S expression and significantly attenuate HCC progression in vitro and in vivo, which may represent a promising strategy for HCC therapy.

BackgroundSomatic mutations are involved in hepatocellular carcinoma (HCC) progression, but the genetic mechanism associated to hepatocarcinogenesis remains poorly understood. We report that Eyes absent homolog 2 (EYA2) suppresses the HCC progression, while EYA2(A510E) mutation identified by exome sequencing attenuates the tumor-inhibiting effect of EYA2.MethodsWhole-exome sequencing was performed on six pairs of human HCC primary tumors and matched adjacent tissues. Focusing on EYA2, expression level of EYA2 in human HCC samples was evaluated by quantitative real-time PCR, western blot and immunohistochemistry. Loss- and gain-of-function studies, hepatocyte-specific deletion of EYA2 (Eya2−/−) in mice and RNA sequencing analysis were used to explore the functional effect and mechanism of EYA2 on HCC cell growth and metastasis. EYA2 methylation status was evaluated using Sequenom MassARRAY and publicly available data analysis.ResultsA new somatic mutation p.Ala510Glu of EYA2 was identified in HCC tissues. The expression of EYA2 was down-regulated in HCC and associated with tumor size (P = 0.001), Barcelona Clinic Liver Cancer stage (P = 0.016) and tumor differentiation (P = 0.048). High level of EYA2 was correlated with a favorable prognosis in HCC patients (P = 0.003). Results from loss-of-function and gain-of-function experiments suggested that knockdown of EYA2 enhanced, while overexpression of EYA2 attenuated, the proliferation, clone formation, invasion, and migration of HCC cells in vitro. Delivery of EYA2 gene had a therapeutic effect on inhibition of orthotopic liver tumor in nude mice. However, EYA2(A510E) mutation led to protein degradation by unfolded protein response, thus weakening the inhibitory function of EYA2. Hepatocyte-specific deletion of EYA2 in mice dramatically promoted diethylnitrosamine-induced HCC development. EYA2 was also down-regulated in HCC by aberrant CpG methylation. Mechanically, EYA2 combined with DACH1 to transcriptionally regulate SOCS3 expression, thus suppressing the progression of HCC via SOCS3-mediated blockade of the JAK/STAT signaling pathway.ConclusionsIn our study, we identified and validated EYA2 as a tumor suppressor gene in HCC, providing a new insight into HCC pathogenesis.

The persistence of macrophage-derived foam cells in the artery wall fuels atherosclerosis development. However, the mechanism of foam cell formation regulation remains elusive. We are committed to determining the role that CD147 might play in macrophage foam cell formation during atherosclerosis. In this study, we found that CD147 expression was primarily increased in mouse and human atherosclerotic lesions that were rich in macrophages and could be upregulated by ox-LDL. High-throughput compound screening indicated that ox-LDL-induced CD147 upregulation in macrophages was achieved through PI3K/Akt/mTOR signaling. Genetic deletion of macrophage CD147 protected against foam cell formation by impeding cholesterol uptake, probably through the scavenger receptor CD36. The opposite effect was observed in primary macrophages isolated from macrophage-specific CD147-overexpressing mice. Moreover, bioinformatics results indicated that CD147 suppression might exert an atheroprotective effect via various processes, such as cholesterol biosynthetic and metabolic processes, LDL and plasma lipoprotein clearance, and decreased platelet aggregation and collagen degradation. Our findings identify CD147 as a potential target for prevention and treatment of atherosclerosis in the future.

In face of the everlasting battle toward COVID-19 and the rapid evolution of SARS-CoV-2, no specific and effective drugs for treating this disease have been reported until today. Angiotensin-converting enzyme 2 (ACE2), a receptor of SARS-CoV-2, mediates the virus infection by binding to spike protein. Although ACE2 is expressed in the lung, kidney, and intestine, its expressing levels are rather low, especially in the lung. Considering the great infectivity of COVID-19, we speculate that SARS-CoV-2 may depend on other routes to facilitate its infection. Here, we first discover an interaction between host cell receptor CD147 and SARS-CoV-2 spike protein. The loss of CD147 or blocking CD147 in Vero E6 and BEAS-2B cell lines by anti-CD147 antibody, Meplazumab, inhibits SARS-CoV-2 amplification. Expression of human CD147 allows virus entry into non-susceptible BHK-21 cells, which can be neutralized by CD147 extracellular fragment. Viral loads are detectable in the lungs of human CD147 (hCD147) mice infected with SARS-CoV-2, but not in those of virus-infected wild type mice. Interestingly, virions are observed in lymphocytes of lung tissue from a COVID-19 patient. Human T cells with a property of ACE2 natural deficiency can be infected with SARS-CoV-2 pseudovirus in a dose-dependent manner, which is specifically inhibited by Meplazumab. Furthermore, CD147 mediates virus entering host cells by endocytosis. Together, our study reveals a novel virus entry route, CD147-spike protein, which provides an important target for developing specific and effective drug against COVID-19.

Background Cancer stem cells (CSCs), responsible for cancer metastasis and recurrence, are generated from non-CSCs after chemo-radiation therapy. This study investigated the induction of CSC potential in non-stem breast cancer cells and the underlying molecular mechanisms in detachment culture. Methods Bulk breast cancer cells, or sorted non-CSCs and CSCs were cultured under an attached or detached condition to assess CSC numbers, ability to form tumor spheres, expression of stemness markers, and chemoresistance. Lentivirus carrying CD147 shRNA or cDNA was used to manipulate CD147 expression, while CD147 ligand recombinant cyclophilin A (CyPA) or its inhibitor was used to activate or inhibit CD147 signaling. Results Detachment promoted anoikis resistance, chemoresistance, sphere formation, self-renewal, and expression of stemness markers in breast cancer cells. Detachment increased functional ALDH+ or CD44highCD24-/low CSCs, and induced CSC potential in ALDH- or CD44 low CD24high non-CSCs. Upon detachment, both CD147 expression and CyPA secretion were enhanced, and CyPA-CD147 activation mediated detachment induced CSC potential in non-CSCs via STAT3 signaling. Clinically, CD147 and pSTAT3 were highly co-expressed and correlated with poor overall survival and tumor recurrence in breast cancer patients. Conclusion This study demonstrates that detachment induces the generation of CSCs from non-stem breast cancer cells via CyPA-CD147 signaling, indicating that targeting CD147 may serve as a potential novel therapeutic strategy for lethal metastatic breast cancer by eliminating induced CSCs.

Cluster of differentiation 147 (CD147) is a transmembrane glycoprotein belonging to the immunoglobulin superfamily. CD147 overexpression has been reported to facilitate the development of hepatocellular carcinoma (HCC) and influence immunologic disorders. Although increased expression of CD147 was reported in non-alcoholic steatohepatitis (NASH), functions of CD147 in NASH have not been evaluated. Firstly, we confirmed that CD147 expression was increased in the liver tissues from methionine-choline-deficient (MCD) diet-induced NASH model mice and NASH patients. Mice with hepatocyte-specific CD147 deletion exhibited attenuated NASH phenotypes, including reduced steatosis, liver injury, hepatocyte apoptosis and inflammatory cytokines IL-1β/IL-18 secretion. Following the administration of the MCD diet, NLRP3 expression was increased gradually along with CD147 expression. Furthermore, CD147 deletion inhibited the NF-κB/NLRP3 signaling pathway in both MCD diet-induced mice and primary hepatocytes. Finally, CypA inhibitor TMN355 attenuated liver steatosis and injury and inhibited NF-κB/NLRP3 signaling pathway. Therefore, our results suggest that CD147 played a vital role in NASH pathogenesis by regulating the inflammatory response, and CypA/CD147 could be attractive therapeutic targets for NASH treatment.

Background Mounting evidence suggests that solid tumors display the features of collective invasion, however, the molecular mechanisms are far from clear. This study aims to verify the role and the underlying mechanisms of CD147 in collective invasion in hepatocellular carcinoma. Methods Immunostaining was used to analyze human hepatocellular carcinoma specimens and three-dimensional cultures. Three-dimensional invasion model was established to mimic in vivo invasion. RNA-sequencing was used to identify downstream effectors. Results Human hepatocellular carcinoma underwent collective invasion and CD147 was observed to be upregulated at the invasive front of tumor cell groups. CD147 was demonstrated to promote collective invasion using the modified three-dimensional invasion model, which recapitulated the main features of collective invasion. Through transcriptome analysis and enzyme activity assay, we found that CD147 enhanced cathepsin B expression and activity. Upregulated cathepsin B in hepatocellular carcinoma cells facilitated migration and invasion, which mediated CD147-induced invasive phenotype in hepatocellular carcinoma. In terms of mechanism, we found that CD147 promoted cathepsin B transcription by activating β-catenin signaling as a result of reduced GSK-3β expression. Furthermore, we found that elevated expression of CD147 as well as cathepsin B were correlated with poor prognosis in patients with hepatocellular carcinoma. Conclusions CD147 promotes hepatocellular carcinoma cells collective invasion via upregulating cathepsin B expression and targeting CD147 would be valuable for the development of novel therapeutic modalities against invasion and metastasis of cancer.

SummaryBackgroundSARS-CoV-2 is a novel human coronavirus, there is no specific antiviral drugs. It has been proved that host-cell-expressed CD147 could bind spike protein of SARS-CoV-2 and involve in host cell invasion. Antibody against CD147 could block the infection of SARS-CoV-2. We aimed to assess the efficacy and safety of meplazumab, a humanized anti-CD147 antibody, as add-on therapy in patients with COVID-19 pneumonia.MethodsAll patients received recommended strategy fromChinese Clinical Guidance for COVID-19 Pneumonia Diagnosis and Treatmentsreleased by National Health Commission of China. Eligible patients were add-on administered 10 mg meplazumab intravenously at days 1, 2, and 5. Patients hospitalized in the same period were observed as concurrent control. The endpoints include virological clearance rate, case severity, chest radiographic, and laboratory test. This trial was approved by the Ethics Committee of Institution at the Tangdu hospital, and registered with ClinicalTrials.gov, NCT 04275245.Findings17 patients were enrolled and assigned to meplazumab group between Feb 3, 2020 and Feb 10, 2020. 11 hospitalized patients served as concurrent control. Baseline characteristics were generally balanced across two groups. Compared to control group, meplazumab treatment significantly improved the discharged (p=0.005) and case severity (p=0.021) in patients. The time to virus negative in meplazumab group was reduced than that in control group (median 3, 95%CI[1.5-4.5] vs. 13, [6.5-19.5]; p=0.045, HR=0.374, 95%CI[0.143-0.978]). The percentages of patients recovered to the normal lymphocyte count and CRP concentration were also increased remarkably and rapidly in meplazumab group. No adverse effect was found in meplazumab-treated patients.InterpretationMeplazumab efficiently improved the recovery of patients with SARS-CoV-2 pneumonia with a favorable safety profile. Our results support to carry out a large-scale investigation of meplazumab as a treatment for COVID-19 pneumonia.FundingNational Science and Technology Major Project.

SUMMARYCurrently, COVID-19 caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has been widely spread around the world; nevertheless, so far there exist no specific antiviral drugs for treatment of the disease, which poses great challenge to control and contain the virus. Here, we reported a research finding that SARS-CoV-2 invaded host cells via a novel route of CD147-spike protein (SP). SP bound to CD147, a receptor on the host cells, thereby mediating the viral invasion. Our further research confirmed this finding. First, in vitro antiviral tests indicated Meplazumab, an anti-CD147 humanized antibody, significantly inhibited the viruses from invading host cells, with an EC50 of 24.86 μg/mL and IC50 of 15.16 μg/mL. Second, we validated the interaction between CD147 and SP, with an affinity constant of 1.85×10−7M. Co-Immunoprecipitation and ELISA also confirmed the binding of the two proteins. Finally, the localization of CD147 and SP was observed in SARS-CoV-2 infected Vero E6 cells by immuno-electron microscope. Therefore, the discovery of the new route CD147-SP for SARS-CoV-2 invading host cells provides a critical target for development of specific antiviral drugs.

While the importance of protein N-glycosylation in cancer cell migration is well appreciated, the precise mechanisms by which N-acetylglucosaminyltransferase V (GnT-V) regulates cancer processes remain largely unknown. In the current study, we report that GnT-V-mediated N-glycosylation of CD147/basigin, a tumor-associated glycoprotein that carries β1,6-N-acetylglucosamine (β1,6-GlcNAc) glycans, is upregulated during TGF-β1-induced epithelial-to-mesenchymal transition (EMT), which correlates with tumor metastasis in patients with hepatocellular carcinoma (HCC). Interruption of β1,6-GlcNAc glycan modification of CD147/basigin decreased matrix metalloproteinase (MMP) expression in HCC cell lines and affected the interaction of CD147/basigin with integrin β1. These results reveal that β1,6-branched glycans modulate the biological function of CD147/basigin in HCC metastasis. Moreover, we showed that the PI3K/Akt pathway regulates GnT-V expression and that inhibition of GnT-V-mediated N-glycosylation suppressed PI3K signaling. In summary, β1,6-branched N-glycosylation affects the biological function of CD147/basigin and these findings provide a novel approach for the development of therapeutic strategies targeting metastasis. © 2018 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of Pathological Society of Great Britain and Ireland.

Hepatocytes are epithelial cells with highly specialized polarity. The disorder and loss of hepatocyte polarity leads to a weakness of cell adhesion and connection, the induction of epithelial–mesenchymal transition, and eventually the occurrence of hepatocellular carcinoma (HCC). Cluster of differentiation 147 (CD147), a tumor‐related glycoprotein, promotes epithelial–mesenchymal transition and the invasion of HCC. However, the function of CD147 in hepatocyte depolarization is unknown. Here we identified that CD147 was basolaterally polarized in hepatocyte membrane of liver tissues and HepG2 cells. CD147 not only promoted transforming growth factor‐β1–mediated hepatocyte polarity loss but also directly induced endocytosis and down‐regulation of E‐cadherin which contributed to hepatocyte depolarization. Overexpression of CD147 induced Src activation and subsequently recruited ubiquitin ligase Hakai for E‐cadherin ubiquitination and lysosomal degradation, leading to decreases of partitioning defective 3 expression and β‐catenin nuclear translocation. This signal transduction was initiated by competitive binding of CD147 with integrin β1 that interrupted the interaction between the Arg‐Gly‐Asp motif of fibronectin and integrin β1. The specific antibodies targeting integrin α5 and β1 reversed the decrease of E‐cadherin and partitioning defective 3 levels induced by CD147 overexpression. In human liver tissues, CD147 polarity rates significantly declined from liver cirrhosis (71.4%) to HCC (10.4%). CD147‐polarized localization negatively correlated with Child‐Pugh scores in human liver cirrhosis (r = –0.6092, P < 0.0001) and positively correlated with differentiation grades in HCC (r = 0.2060, P = 0.004). HCC patients with CD147‐polarized localization had significantly better overall survival than patients with CD147 nonpolarity (P = 0.021). Conclusion: The ectopic CD147‐polarized distribution on basolateral membrane promotes hepatocyte depolarization by activation of the CD147–integrin α5β1–E‐cadherin ubiquitination–partitioning defective 3 decrease and β‐catenin translocation signaling cascade, replenishing a molecular pathway in hepatic carcinogenesis. (Hepatology 2018;68:317‐332).

CD147, encoded by BSG, is a highly glycosylated transmembrane protein that belongs to the immunological superfamily and expressed on the surface of many types of cancer cells. While CD147 is best known as a potent inducer of extracellular matrix metalloproteinases, it can also function as a key mediator of inflammatory and immune responses. To systematically elucidate the function of CD147 in cancer cells, we performed an analysis of genome-wide profiling across the Cancer Cell Line Encyclopedia (CCLE). We showed that CD147 mRNA expression was much higher than that of most other genes in cancer cell lines. CD147 varied widely across these cell lines, with the highest levels in the ovary (COLO704) and stomach (SNU668), intermediate levels in the lung (RERFLCKJ, NCIH596 and NCIH1651) and lowest levels in hematopoietic and lymphoid tissue (UT7, HEL9217, HEL and MHHCALL3) and the kidney (A704 and SLR20). Genome-wide analyses showed that CD147 expression was significantly negatively correlated with immune-related genes. Our findings implicated CD147 as a novel regulator of immune-related genes and suggest its important role as a master regulator of immune-related responses in cancer cell lines. We also found a high correlation between the expression of CD147 and FOXC1, and proved that CD147 was a direct transcriptional target of FOXC1. Our findings demonstrate that FOXC1 is a novel regulator of CD147 and confirms its role as a master regulator of the immune response.

Cluster of differentiation (CD)147 is highly involved in the T cell activation process. High CD147 expression is observed on the surfaces of activated T cells, particularly CD4+ T cells. In organ transplantation, it is important to prevent graft rejection resulting from the excessive activation of T cells, particularly CD4+ T cells, which exhibit a key role in amplifying the immune response. The present study aimed to investigate the effects of CD147 blockade in vitro and in vivo and used a transplant rejection system to assess the feasibility of utilizing CD147 antibody‑based immunosuppressant drugs for the treatment of graft rejection. The effects of CD147 antibodies were evaluated on lymphocyte proliferation stimulated by phytohemagglutinin or CD3/CD28 magnetic beads and in a one‑way mixed lymphocyte reaction (MLR) system in vitro. For the in vivo analysis, an allogeneic skin transplantation mouse model was used. CD147 antibodies were effective against lymphocytes, particularly CD4+T lymphocytes, and were additionally effective in the one‑way MLR system. In the allogeneic skin transplantation mouse model, the survival of transplanted skin was extended in the CD147 antibody‑treated group. Furthermore, the level of inflammatory cell infiltration in transplanted skin was reduced. CD147 blockade decreased the serum levels of interleukin (IL)‑17 and the proportions of peripheral blood CD4+ and CD8+ memory T cells. The data demonstrated that CD147 blockade suppressed skin graft rejection, primarily by suppressing CD4+T and memory T cell proliferation, indicating that CD147 exhibits great potential as a target of immunosuppressant drugs.

CD147 is highly expressed on the surface of numerous tumor cells to promote invasion and metastasis. Targeting these cells with CD147-specific antibodies has been validated as an effective approach for lung and liver cancer therapy. In the immune system, CD147 is recognized as a co-stimulatory receptor and impacts the outcome of thymic selection. Using T cell-specific deletion, we showed here that in thymus CD147 is indispensable for the stable αβ T cell lineage commitment: loss of CD147 biases both multipotent DN (double negative) and fully committed DP (double positive) cells into innate NK-like lineages. Mechanistically, CD147 deficiency results in impaired Wnt signaling and expression of BCL11b, a master transcription factor in determining T cell identity. In addition, functional blocking of CD147 by antibody phenocopies genetic deletion to enrich NK-like cells in the periphery. Furthermore, using a melanoma model and orthotopic liver cancer transplants, we showed that the augmentation of NK-like cells strongly associates with resistance against tumor growth upon CD147 suppression. Therefore, besides its original function in tumorigenesis, CD147 is also an effective surface target for immune modulation in tumor therapy., Highlights • DN, DP cells were reprogrammed into innate NK-like cells after thymic CD147 deleted • Loss of CD147 results in impaired Bcl11b expression and T-lineages development, which can be rescued by Wnt3a stimulation. • CD147 is an vital target for immune modulation via NK-like cells in tumor therapy. Tumor therapy is a difficult task and many methods have been used. Among them, tumor immunotherapy is a focus in the field and has made great progress. In this study, we found CD147 is an vital target for immune modulation via NK-like cells in tumor therapy, which means CD147 antibody may be through regulating immune cells to achieve tumor therapy. Although CD147 antibody has been used for liver cancer, making clear the mechanism of CD147 antibody mediated tumor therapy may be benefit for guiding clinical treatment.

Proteomic-based approaches for biomarker discovery are promising strategies used in cancer research. In this study, we performed quantitative proteomic analysis on 16 paired samples of non-small cell lung cancer (NSCLC) and adjacent non-tumor lung tissues using label-free quantitative proteomics and liquid chromatography-tandem mass spectrometry/mass spectrometry (LC-MS/MS) to identify differentially expressed proteins. A total of 91 proteins were differentially expressed in NSCLC compared with adjacent non-tumor lung tissues among 4047 identified proteins (fold change > 1.5 or < 0.67, P < 0.05). Gene ontology (GO) analysis, Kyoto encyclopedia of genes and genomes (KEGG) pathway analysis and ingenuity pathway analysis (IPA) of 91 dysregulated proteins showed that they were related to the cancer-associated biological processes. We confirmed that the candidate proteins, calreticulin (CALR) and protein disulfide isomerase family A member 3 (PDIA3) were overexpressed in NSCLC by real-time PCR using 20 paired samples and western blot using 5 paired samples. PDIA3 expression was highly associated with CALR expression (Spearman r = 0.345, P = 0.001) and they were co-localized and interacted with each other in A549 and H460 cells. Moreover, survival analysis performed in tissue microarray with 88 samples indicated that low expression of both CALR and PDIA3 in NSCLC was positively associated with poor overall survival. Combination of CALR and PDIA3 might serve as an efficient biomarker and improved the prediction of NSCLC prognosis significantly (P = 0.023). Our results collectively provide a potential biomarker dataset for NSCLC prognosis, especially the prognostic value of combined expression of CALR and PDIA3.

The immunoglobulin superfamily member CD147 is a widely expressed glycoprotein that occurs in both a membrane-spanning and soluble form. Sandwich ELISA is a powerful tool for analyzing soluble antigens. The aim of the present study was to obtain a highly specific polyclonal antibody against human CD147 that can be used for sandwich ELISA analysis. Expression of recombinant CD147 by a eukaryotic expression system was used to immunize rabbits to obtain antiserum. A highly specific polyclonal antibody that was able to detect soluble CD147 in sandwich ELISA was obtained by antigen-immunoaffinity chromatography purification. The purity of rabbit anti-CD147 polyclonal antibodies was ~99%, and ELISA analysis was able to determine the titer of the rabbit anti-CD147 polyclonal antibodies at 1:512,000. The lowest concentration of the standard CD147 antigen that the sandwich ELISA was able to detect was 31.25 pg/ml. The sandwich ELISA system was composed of anti-hepatoma HAb18 monoclonal antibodies and purified rabbit anti-CD147 polyclonal antibodies. The present study demonstrated that antigen-immunoaffinity chromatography may be a good technique for the purification of polyclonal antibodies, which may be used to detect antigen in sandwich ELISAs.

The aim of the present study was to investigate the prognostic significance of the expression of transcription factors, c-Fos, c-Jun and transmembrane protein CD147, in urothelial carcinoma of the bladder (UCB). The current study investigated the clinical significance of these factors in the development, progression and survival analysis of UCB. Immunohistochemistry was employed to analyze c‑Fos, c‑Jun and CD147 expression in 41 UCB cases and 34 non‑cancerous human bladder tissues. These results were scored in a semi‑quantitative manner based on the intensity and percentage of tumor cells that presented immunoreactivity. Protein levels of CD147, c‑Fos and c‑Jun expression were upregulated in 22 (53.7%), 10 (24.4%) and 9 (22.0%) UCB cases, respectively. High levels of c‑Jun correlated with the AJCC cancer staging manual (7th edition; P=0.038). Univariate analysis revealed that upregulated CD147 (P=0.038) or c‑Jun (P=0.008) was associated with poor overall survival (OS), respectively. Further analysis revealed that either CD147‑c‑Fos‑c‑Jun co‑expression (P=0.004), or CD147‑c‑Jun co‑expression (P=0.037) and c‑Fos‑c‑Jun co‑expression (P

Blockade of the immunosuppressive checkpoint receptors cytotoxic T-lymphocyte-associated protein 4 (CTLA4) or programmed death 1 (PD-1) and its cognate ligand, programmed death 1 ligand (PD-L1), has altered the landscape of anti-tumor immunotherapy. B7 family and tumor necrosis factor receptor (TNFR) superfamily play a crucial role in T cell activation, tolerance, and anergy through co-stimulatory and inhibitory signal transduction. Investigating the immune molecular landscapes of the B7 and TNFR families is critical in defining the promising responsive candidates. Herein, we performed comprehensive alteration analysis of the B7 and TNFR family genes across six hepatocellular carcinoma (HCC) datasets with over 1000 patients using cBioPortal TCGA data. About 16% of patients had both B7 and TNFR gene alterations. TNFR gene amplifications were relatively more common (1.73&ndash, 8.82%) than B7 gene amplifications (1.61&ndash, 2.94%). Analysis of 371 sequenced samples revealed that all genes were upregulated: B7 and TNFR mRNA were upregulated in 23% of cases (86/371) and 28% of cases (105/371), respectively. Promoter methylation analysis indicated an epigenetic basis for B7 and TNFR gene regulation. The mRNA levels of B7 and TNFR genes were inversely correlated with promoter methylation status. B7-H6 expression was significantly associated with worse overall survival, and B7-H6 mRNA was increased gradually in cases with gene copy number alterations. B7-H6 overexpression was associated with aggressive clinicopathologic features and poor prognosis in HCC. Downregulation of B7-H6 in HCC cells significantly inhibited cell adhesion, proliferation, migration, and invasion. Knockdown of B7-H6 in HCC cells inhibited tumor growth and metastasis in vivo. B7-H6 promoted HCC metastasis via induction of MMP-9 expression and STAT3 activation. B7-H6 and STAT3 performed functional overlapping roles on enhancing the MMP-9 promoter activity in HCC cells. These results suggest that alterations of the immunologic co-stimulator B7 and TNFR families correlate with HCC metastasis and prognosis, and especially B7-H6 plays a critical role in promoting metastasis of HCC.

The purpose of this study was to investigate the expression of microRNA-202 (miR-202) and its role in colorectal cancer (CRC) in vivo and in vitro. We examined the expression of miR-202 in CRC tissues by quantitative real-time PCR (qRT-PCR) assay. Lentiviral vectors were constructed to overexpress or inhibit the expression of miR-202 in the CRC cell lines HCT116 and SW480 to determine its effects on cell invasion and proliferation. We found that overexpression of miR-202 significantly inhibited the proliferation and invasion of HCT116 cells. MiRNA target gene prediction, dual luciferase assay, and western blot analysis demonstrated that miR-202 regulated ubiquitin-like with PHD and RING finger domain 1 (UHRF1) expression in both cell lines. The effect of miR-202 on cell proliferation and invasion was partially reversed by activating the expression of UHRF1. Furthermore, miR-202 induced tumor formation in HCT116 xenograft BALB/c nude mice. Mice vaccinated with miR-202-overexpressing cells had smaller tumors and lower UHRF1 expression than the control group. These results indicate the possibility that miR-202 is under-expressed in CRC tissues, and that miR-202 inhibits the proliferation and invasion of CRC via targeting UHRF1. MiR-202 is a potential therapeutic target for CRC.

CD147 is a tumor-associated glycoprotein that regulates cell metabolism. However, CD147 methylation and its subsequent role in cancer cell metabolism remain unclear. Here, we detect CD147 di-methylation in 16 non-small-cell lung cancer (NSCLC) tissues using liquid chromatography-tandem mass spectrometry. CD147 is di-methylated to CD147-K234me2 by lysine methyltransferase 5A (KMT5A). The increase in KMT5A expression boosts the levels of CD147-K234me2, further promoting the interaction between CD147 and monocarboxylate transporter 4 (MCT4), which enhances the translocation of MCT4 from the cytoplasm to the membrane. Overexpression of CD147-K234me2 and KMT5A enhances glycolysis and lactate export in NSCLC cells. Clinical analysis shows that high CD147-K234me2 expression is significantly related to cancer progression and overall survival, and has prognostic significance in individuals with NSCLC, especially for those in the early stages. Our findings indicate that CD147-K234me2 plays a critical role in cancer metabolism, and it can be a highly promising therapeutic target for NSCLC.

// Bao-Qing Xu 1, * , Zhi-Guang Fu 1, * , Yao Meng 1, * , Xiao-Qing Wu 2 , Bo Wu 1 , Liang Xu 2 , Jian-Li Jiang 1 , Ling Li 1 , Zhi-Nan Chen 1 1 Department of Cell Biology and Cell Engineering Research Center, State Key Laboratory of Cancer Biology, National Key Discipline of Cell Biology, Fourth Military Medical University, Xi’an, China 2 Departments of Molecular Biosciences and Radiation Oncology, University of Kansas, Lawrence, Kansas, USA * These authors have contributed equally to this work Correspondence to: Zhi-Nan Chen, email: znchen@fmmu.edu.cn Ling Li, email: liling25@fmmu.edu.cn Keywords: gemcitabine, stress, invasion, HAb18G/CD147, EGFR Received: March 20, 2015 Accepted: August 08, 2016 Published: August 19, 2016 ABSTRACT Pancreatic cancer, one of the most lethal cancers, has very poor 5-year survival partly due to gemcitabine resistance. Recently, it was reported that chemotherapeutic agents may act as stressors to induce adaptive responses and to promote chemoresistance in cancer cells. During long-term drug treatment, the minority of cancer cells survive and acquire an epithelial-mesenchymal transition phenotype with increased chemo-resistance and metastasis. However, the short-term response of most cancer cells remains unclear. This study aimed to investigate the short-term response of pancreatic cancer cells to gemcitabine stress and to explore the corresponding mechanism. Our results showed that gemcitabine treatment for 24 hours enhanced pancreatic cancer cell invasion. In gemcitabine-treated cells, HAb18G/CD147 was up-regulated; and HAb18G/CD147 down-regulation or inhibition attenuated gemcitabine-enhanced invasion. Mechanistically, HAb18G/CD147 promoted gemcitabine-enhanced invasion by activating the EGFR (epidermal growth factor receptor)-STAT3 (signal transducer and activator of transcription 3) signaling pathway. Inhibition of EGFR-STAT3 signaling counteracted gemcitabine-enhanced invasion, and which relied on HAb18G/CD147 levels. In pancreatic cancer tissues, EGFR was highly expressed and positively correlated with HAb18G/CD147. These data indicate that pancreatic cancer cells enhance cell invasion via activating HAb18G/CD147-EGFR-pSTAT3 signaling. Our findings suggest that inhibiting HAb18G/CD147 is a potential strategy for overcoming drug stress-associated resistance in pancreatic cancer.

Basigin is a well-known extracellular stimulator of fibroblasts and may confer resistance to apoptosis of fibroblasts in vitro under some pathological status, but its exact function in fibroblasts and the underlying mechanism remain poorly understood. The systematic Basigin gene knockout leads to the perinatal lethality of mice, which limits the delineation of its function in vivo. In this study, we generated a fibroblast-specific Basigin knock-out mouse model and demonstrated the successful deletion of Basigin in fibroblasts. The fibroblast-specific deletion of Basigin did not influence the growth, fertility and the general condition of the mice. No obvious differences were found in the size, morphology, and histological structure of the major organs, including heart, liver, spleen, lung and kidney, between the knockout mice and the control mice. The deletion of Basigin in fibroblasts did not induce apoptosis in the tissues of the major organs. These results provide the first evidence that the fibroblast-specific Basigin knock-out mice could be a useful tool for exploring the function of Basigin in fibroblasts in vivo.

Ankylosing spondylitis (AS) is a chronic autoimmune inflammatory disease with severe inflammatory symptoms in the axial skeleton. The cause of ankylosing spondylitis is unknown. TNFAIP3, also named A20, uses ubiquitin-related functions to regulate immune activation, deficiency of which is highly related to autoimmune disease. However, the role of TNFAIP3 in human AS has not been reported. Our objective was to study the role and mechanism of TNFAIP3 in ankylosing spondylitis. TNFAIP3 expression on different types of immunocytes from AS peripheral blood was measured by flow cytometry. In vitro, monocytes were transfected with a TNFAIP3 shRNA lentivirus, and IL6 and IL1B activation was tested using real-time PCR and ELISA. The novel interaction complex TNFAIP3-DEPTOR was determined through GST pull-down, yeast two-hybrid system, confocal microscopy, and co-immunoprecipitation. Transmission electron microscopy, the RFP-GFP-LC3 adenovirus, and LC3 expression were used for autophagy detection. Here, we show that TNFAIP3 expression in AS peripheral blood non-classical monocytes was decreased. In normal monocytes, TNFAIP3 induced autophagy, which restricted inflammasome activation to the early stage of LPS stimulation. Zinc-finger domains of TNFAIP3 were able to interact and stabilize DEPTOR. TNFAIP3 and DEPTOR together rapidly promoted autophagy after LPS treatment to prevent NLRP3 inflammasome formation. Finally, TNFAIP3 and DEPTOR deficiency in AS non-classical monocytes facilitated inflammasome activation. Our study indicates that TNFAIP3-DEPTOR complex-induced early-onset autophagy is vital for immune inhibition in autoimmune disease.

Activated hepatic stellate cells (HSCs) release pro-inflammatory and pro-fibrogenic factors. CXC chemokine-ligand-1 (CXCL1) is expressed on HSCs. We previously found that the CD147 is overexpressed in activated HSCs. In this study, we showed an important role of CD147 in promoting liver fibrosis by activating HSCs and upregulating expression of chemokines. Specifically, we found that CD147 specific deletion in HSCs mice alleviated CCl4-induced liver fibrosis and inhibited HSCs activation. Overexpression of CD147 upregulated the secretion of CXCL1. Meanwhile, CXCL1 promoted HSCs activation through autocrine. Treating with PI3K/AKT inhibitor could effectively suppress CD147-induced CXCL1 expression. Taken together, these findings suggest that CD147 regulates CXCL1 release in HSCs by PI3K/AKT signaling. Inhibition of CD147 attenuates CCl4-induced liver fibrosis and inflammation. Therefore, administration of targeting CD147 could be a promising therapeutic strategy in liver fibrosis.

SUMMARYProteins are usually deciphered by translation of the coding genome; however, their amino acid residues are seldom determined directly across the proteome. Herein, we describe a systematic workflow for identifying all possible protein residues that differ from the coding genome, termed noncoded amino acids (ncAAs). By measuring the mass differences between the coding amino acids and the actual protein residues in human spermatozoa, over a million nonzero delta masses were detected, fallen into 424 high-quality Gaussian clusters and 571 high-confidence ncAAs spanning 29,053 protein sites. Most ncAAs are novel with unresolved side-chains and discriminative between healthy individuals and patients with oligoasthenospermia. For validation, 40 out of 98 ncAAs that matched with amino acid substitutions were confirmed by exon sequencing. This workflow revealed the widespread existence of previously unreported ncAAs in the sperm proteome, which represents a new dimension on the understanding of amino acid polymorphisms at the proteomic level.Highlights571 ncAAs spanning 108,000 protein sites were identified in human sperm proteome.Most ncAAs are novel with unresolved sidechains and found at unreported protein sites.Exon sequencing confirmed 40 of 98 ncAAs that matched with amino acid substitutions.Many ncAAs are linked with disease and have potential for diagnosis and targeting.eTOC BlurbWe describe a systematic identification of all possible protein residues that were not encoded by their genomic sequences. A total of 571 high-confidence most novel noncoded amino acids were identified in human sperm proteome, corresponding to over 108,000 ncAA-containing protein sites. For validation, 40 out of 98 ncAAs that matched to amino acid substitutions were confirmed by exon sequencing. These ncAAs are discriminative between individuals and expand our understanding of amino acid polymorphisms in human proteomes and diseases.

miR-362 is a recently discovered member of the microRNA family, and it modulates a variety of physical activities and plays an important role in the occurrence and development of many tumors. However, the biological functions of hsa-miR-362-5p in non-small-cell lung carcinoma (NSCLC) are unknown. Transwell assay and colony formation were used to determine the migration, invasion, and proliferation of NSCLC cells in vitro. A subcutaneous tumor model in nude mice was established to detect NSCLC tumor growth in vivo. The direct binding of miR-362 to the 3′UTR of Semaphorin 3A (Sema3A) was confirmed by luciferase reporter assay. In this study, we found that the level of miR-362 was higher in NSCLC tissues than in adjacent normal tissues and that the level of miR-362 expression was also elevated in five NSCLC cell lines (A549, 95-D, H1299, H292, and H460) relative to a human normal lung epithelial cell line (BEAS2B). Furthermore, miR-362 promoted NSCLC cell invasion, migration, and colony formation in vitro and tumor formation in vivo. Next, we identified the miR-362 target gene Sema3A, which is significantly correlated with metastasis. Sema3A expression was increased in normal tissues relative to NSCLC tissues. This result is consistent with the fact that miR-362 expression is negatively correlated with Sema3A expression in clinical tissue samples and indicated that miR-362 can regulate Sema3A expression in NSCLC cells and consequently affect NSCLC invasion, migration, and colony formation. Taken together, these findings on the newly identified miR-362/Sema3A axis elucidate the molecular mechanism of NSCLC invasion and migration and could lead to a potential therapeutic target in NSCLC treatment.

The acquisition of inappropriate migratory feature is crucial for tumor metastasis. It has been suggested that CD147 and Annexin A2 are involved in regulating tumor cell movement, while the regulatory mechanisms are far from clear. In this study, we demonstrated that CD147 physically interacted with the N-terminal domain of Annexin A2 and decreased Annexin A2 phosphorylation on tyrosine 23. In vitro kinase assay showed that the I domain of CD147 was indispensable for CD147-mediated downregulation of Annexin A2 phosphorylation by Src. Furthermore, we determined that p-Annexin A2 promoted the expression of dedicator of cytokinesis 3 (DOCK3) and DOCK3 blocked β-catenin nuclear translocation, resulting in inhibition of β-catenin signaling. In addition, DOCK3 inhibited lamellipodium dynamics and tumor cell movement. Also, we found that β-catenin signaling increased WAVE2 expression. Therefore, DOCK3 was characterized as a negative regulator of WAVE2 expression via inhibiting β-catenin signaling. Our study provides the first evidence that CD147 promotes tumor cell movement and metastasis via direct interaction with Annexin A2 and DOCK3-β-catenin-WAVE2 signaling axis.

Homotypic cell aggregation plays important roles in physiological and pathological processes, including embryogenesis, immune responses, angiogenesis, tumor cell invasion and metastasis. CD147 has been implicated in most of these phenomena, and it was identified as a T cell activation-associated antigen due to its obvious up-regulation in activated T cells. However, the explicit function and mechanism of CD147 in T cells have not been fully elucidated. In this study, large and compact aggregates were observed in Jurkat T cells after treatment with the specific CD147 monoclonal antibody HAb18 or after the expression of CD147 was silenced by RNA interference, which indicated an inhibitory effect of CD147 in T cell homotypic aggregation. Knocking down CD147 expression resulted in a significant decrease in CD98, along with prominent cell aggregation, similar to that treated by CD98 and CD147 monoclonal antibodies. Furthermore, decreased cell chemotactic activity was observed following CD147- and CD98-mediated cell aggregation, and increased aggregation was correlated with a decrease in the chemotactic ability of the Jurkat T cells, suggesting that CD147- and CD98-mediated homotypic cell aggregation plays a negative role in T cell chemotaxis. Our data also showed that p-ERK, p-ZAP70, p-CD3ζ and p-LCK were significantly decreased in the CD147- and CD98-knocked down Jurkat T cells, which suggested that decreased CD147- and/or CD98-induced homotypic T cell aggregation and aggregation-inhibited chemotaxis might be associated with these signaling pathways. A role for CD147 in cell aggregation and chemotaxis was further indicated in primary CD4(+) T cells. Similarly, low expression of CD147 in primary T cells induced prominent cell aggregation and this aggregation attenuated primary T cell chemotactic ability in response to CypA. Our results have demonstrated the correlation between homotypic cell aggregation and the chemotactic response of T cells to CypA, and these data indicate that CD147 and CD98 might play important roles in cyclophilin-induced cell migration.

Radiotherapy has played a limited role in the treatment of hepatocellular carcinoma (HCC) due to the risk of tumor radioresistance. A previous study in our laboratory confirmed that CD147 interacts with integrin β1 and plays an important role in modulating the malignant properties of HCC cells. In this study, we further evaluated the role of CD147 in the radioresistance of HCC and as a potential target for improving radiosensitivity. Upon irradiation, the colony formation, apoptosis, cell-cycle distribution, migration, and invasion of SMMC-7721, CD147-knockout SMMC-7721, HepG2, and CD147-knockdown HepG2 cells were determined. A nude mouse xenograft model and a metastatic model of HCC were used to detect the role of CD147 in radioresistance in vivo. Deletion of HAb18G/CD147 significantly enhanced the radiosensitivity of SMMC-7721 and HepG2 cells, and knocking out HAb18G/CD147 in SMMC-7721 cells attenuated irradiation-enhanced migration and invasion. The knockout and antibody blockade of CD147 decreased the tumor growth and metastatic potentials of HCC cells under irradiation. CD147-deleted SMMC-7721 cells showed diminished levels of calpain, cleaved talin, active integrin β1, and decreased p-FAK (Tyr397) and p-Akt (Ser473) levels. FAK and PI3K inhibitors, as well as integrin β1 antibodies, increased the radiation-induced apoptosis of SMMC-7721 cells. Our data provide evidence for CD147 as an important determinant of radioresistance via the regulation of integrin β1 signaling. Inhibition of the HAb18G/CD147 integrin interaction may improve the efficiency of radiosensitivity and provide a potential new approach for HCC therapy. Mol Cancer Ther; 14(2); 553–63. ©2014 AACR.

Metuzumab is an affinity-optimized and nonfucosylated anti-CD147 human–mouse chimeric IgG1 monoclonal antibody with enhanced antibody-dependent cellular cytotoxicity (ADCC). The purpose of this study was to characterize the pharmacokinetics, safety, and antitumor activities of metuzumab in mouse, rat, and monkey. The ADCC activity was assessed by a lactate dehydrogenase release assay. The pharmacokinetics of metuzumab were determined in Sprague–Dawley rats and in cynomolgus monkeys. Single- and repeat-dose toxicology studies of the i.v. administration of high-dose metuzumab were conducted in cynomolgus monkeys. Mice bearing human tumor xenografts were used to evaluate the antitumor efficacy of metuzumab. The ADCC potency of metuzumab was enhanced compared with the nonglycoengineered parental antibody. Metuzumab also effectively inhibited tumor growth in A549 and NCI-H520 xenograft models. In the monkey model, the total clearance of metuzumab decreased with increasing dose. The nonspecific clearance in monkeys was estimated to be 0.53 to 0.92 mL/h/kg. In single- and repeat-dose toxicology studies in cynomolgus monkeys, metuzumab did not induce any distinct or novel adverse findings and was well tolerated at all tested doses. These preclinical safety data facilitated the initiation of an ongoing clinical trial of metuzumab for the treatment of non–small cell lung cancer (NSCLC) in China. Mol Cancer Ther; 14(1); 162–73. ©2014 AACR.

Cluster of differentiation 147 (CD147), pituitary tumor transforming gene (PTTG) and CD44v6 are proteins involved in the epithelial-mesenchymal transition (EMT). To investigate the prognostic value of CD147 and PTTG, and CD44v6 expression in esophageal squamous cell carcinoma (ESCC), tissue microarray specimens from 76 patients with ESCC were evaluated by immunohistochemistry staining and scored by intensity and proportion of positive areas. Expression levels of CD147, PTTG and CD44v6 were higher in tumor tissues than in matched adjacent tissues. CD147 expression was positively associated with lymph node metastasis (P=0.025) and American Joint Committee on Cancer (AJCC) system clinical grades (P=0.037). CD147 expression was positively correlated with the expression levels of PTTG (R=0.369; P=0.001) and CD44v6 (R=0.320; P=0.005). In addition, Kaplan-Meier analysis indicated that positive expression of CD147, PTTG and CD44v6 was significantly associated with poor overall survival times (P=0.045, P=0.014 and P=0.027, respectively). Patients exhibiting CD147-PTTG co-expression, CD147-CD44v6 co-expression and CD147-PTTG-CD44v6 triple-positive expression had the poorest overall survival rates. In conclusion, the expression of EMT-associated proteins, including CD147, PTTG and CD44v6, was significantly associated with poor survival in ESCC and these novel targets may serve as potential biomarkers for anticancer therapies.

Newcastle disease virus (NDV) has been applied to oncolytic virotherapy for decades due to its naturally oncolytic property. In spite of the substantiation of the sialic acid receptors of NDV on host cells, knowledge of preference of sialic acid linkage in viral attachment and oncolytic effect is lacking and imperative to be elucidated. Surface plasmon resonance analysis and competitive inhibition with sialylated glycan receptor analogues were used to determine the affinity and the preference of sialic acid receptor. Treatments of sialyltransferase inhibitors and linkage-specific sialidases and transfection with sialyltransferase expression vector were performed to regulate sialic acids levels. We demonstrated that sialic acid was essential for NDV binding and infection of tumor cells. α2,6-linked sialic acid served as a high-affinity receptor for NDV and the ST6Gal I sialyltransferase that synthesizes α2-6 linkage of sialylated N-linked glycans in CHO-K1 cells promoted NDV binding and cytopathic effect. More importantly, an enhanced antitumor effect of NDV on aggressive SW620 colorectal carcinoma cells with high-level of cell surface α2,6-sialylation, but not SW480 cells with relative low-level of α2,6-sialylation, was observed both in vitro and in vivo. The study provides evidence of optimized therapeutic strategy in oncolytic virotherapy via partly defining α2,6-sialylated receptor as a “cellular marker” for NDV.

Overexpression of CD147/basigin in hepatic cells promotes the progression of hepatocellular carcinoma (HCC). Whether CD147 also expressed in liver non-parenchymal cells and associated with HCC development was unknown. The aim of the study was to explore time-dependent cell expression patterns of CD147 in a widely accepted N-diethylnitrosamine/phenobarbital (DEN/PB)-induced HCC mouse model. Liver samples collected at month 1-12 of post-DEN/PB administration were assessed the localization of CD147 in hepatocytes, endothelial cells, hepatic stellate cells, and macrophages. Immunohistochemistry analysis showed that CD147 was upregulated in liver tumors during month 1-8 of DEN/PB induction. Expression of CD147 was positively correlated with cytokeratin 18, a hepatocyte marker (r = 0.7857, P = 0.0279), CD31 (r = 0.9048, P = 0.0046), an endothelial cell marker, and CD68, a macrophage marker (r = 0.7619, P = 0.0368). A significant correlation was also observed between CD147 and alpha-smooth muscle actin (r = 0.8857, P = 0.0333) at DEN/PB initiation and early stage of tumor formation. Immunofluorescence and fluorescence in situ hybridization showed that CD147 co-expressed with cytokeratin 18, CD31, alpha-smooth muscle actin, and CD68. Moreover, there existed positive correlations between CD147 and microvessel density (r = 0.7857, P = 0.0279), CD147 and Ki-67 (r = 0.9341, P = 0.0022) in the development of DEN/PB-induced HCC. In conclusion, our results demonstrated that CD147 was upregulated in the liver parenchymal and mesenchymal cells and involved in angiogenesis and tumor cell proliferation in the development of DEN/PB-induced HCC.

Epithelial-mesenchymal transition (EMT) induced by the transforming growth factor beta (TGF-β) is involved in hepatocarcinogenesis and hepatocellular carcinoma (HCC) metastasis. HAb18G/CD147, a member of the immunoglobulin family, plays an important role in tumor invasion and metastasis. HAb18G/CD147 promotes EMT of hepatocytes through TGF-β signaling and is transcriptionally regulated by Slug. We investigated the role of HAb18G/CD147 in TGF-β-induced EMT in HCC invasion. Two human HCC cell lines, SMMC-7721 and HepG2, were used to determine the role of HAb18G/CD147 in EMT. Upregulation of HAb18G/CD147 induced by the high doses of TGF-β1 in SMMC-7721 (5 ng/mL) and HepG2 cells (10 ng/mL) (P

Endoplasmic reticulum stress (ER stress) is triggered due to a loss of homeostasis in the ER, resulting in accumulation of misfolded proteins in the ER lumen. ER stress activates a series of adaptive mechanisms known as the unfolded protein response. Perturbation of the ER is a powerful inducer of the transcription factor C/EBP homologous protein (CHOP). Although it has been proved that excessive or adverse stress to the ER triggers apoptosis, the specific mechanisms underlying these processes induced by CHOP remain unclear. By now, CHOP-induced apoptosis in ER stress has been implicated in numerous human diseases, such as neurodegenerative diseases, diabetes, ischemic diseases, tumor, and so on. In this review, we summarized the current understanding of the roles of CHOP in the development of several diseases from the laboratory to the clinic.

Objectives We aimed to investigate whether CD147 can up-regulate the chemotactic, adhesive and invasive properties of human neutrophils and to determine the mechanism underlying this process. Methods Human promyelocytic leukaemia cells (HL-60) cells and peripheral blood or synovial fluid neutrophils were isolated from RA patients. Under cyclophilin A (CypA) stimulation, chemotaxis, adhesion potential and invasion ability were assessed using chemotaxis, adhesion and invasiveness assays. Lipid raft isolation and western blot were used to determine the mechanism underlying the effects of CypA stimulation. Results CD147 up-regulates the calcium-induced chemotaxis, adhesion ability and invasiveness of human neutrophils in RA patients. Transient receptor potential melastatin 7 may be responsible for this phenomenon. Conclusion These findings suggest that in RA patients, abundant CypA up-regulates the calcium-induced chemotactic, adhesive and invasive properties of neutrophils via direct binding to CD147. Cyclophilin-CD147 interactions might contribute to the destruction of cartilage and bone in RA.