Cysteine carboxyethylation generates neoantigens to induce HLA-restricted autoimmunity.

Autoimmune diseases such as ankylosing spondylitis (AS) can be driven by emerging neoantigens that disrupt immune tolerance. Here, we developed a workflow to profile posttranslational modifications involved in neoantigen formation. Using mass spectrometry, we identified a panel of cysteine residues differentially modified by carboxyethylation that required 3-hydroxypropionic acid to generate neoantigens in patients with AS. The lysosomal degradation of integrin αIIb [ITGA2B (CD41)] carboxyethylated at Cys96 (ITGA2B-ceC96) generated carboxyethylated peptides that were presented by HLA-DRB1*04 to stimulate CD4+ T cell responses and induce autoantibody production. Immunization of HLA-DR4 transgenic mice with the ITGA2B-ceC96 peptide promoted colitis and vertebral bone erosion. Thus, metabolite-induced cysteine carboxyethylation can give rise to pathogenic neoantigens that lead to autoreactive CD4+ T cell responses and autoantibody production in autoimmune diseases.

Meplazumab in hospitalized adults with severe COVID-19 (DEFLECT): a multicenter, seamless phase 2/3, randomized, third-party double-blind clinical trial.

Meplazumab, a humanized CD147 antibody, has shown favourable safety and efficacy in our previous clinical studies. In DEFLECT (NCT04586153), 167 patients with severe COVID-19 were enroled and randomized to receive three dosages of meplazumab and a placebo. Meplazumab at 0.12 mg/kg, compared to the placebo group, showed clinical benefits in significantly reducing mortality by 83.6% (2.4% vs. 14.6%, p = 0.0150), increasing the proportion of patients alive and discharged without supplemental oxygen (82.9% vs. 70.7%, p = 0.0337) and increasing the proportion of patients who achieved sustained clinical improvement (41.5% vs. 31.7%). The response rate in the 0.2 mg/kg group was relatively increased by 16.0% compared with the placebo group (53.7% vs. 46.3%). Meplazumab also reduced the viral loads and multiple cytokine levels. Compare with the placebo group, the 0.3 mg/kg significantly increased the virus negative rate by 40.6% (p = 0.0363) and reduced IL-8 level (p = 0.0460); the 0.2 mg/kg increased the negative conversion rate by 36.9%, and reduced IL-4 (p = 0.0365) and IL-8 levels (p = 0.0484). In this study, the adverse events occurred at a comparable rate across the four groups, with no unexpected safety findings observed. In conclusion, meplazumab promoted COVID-19 convalescence and reduced mortality, viral load, and cytokine levels in severe COVID-19 population with good safety profile.

CD147 contributes to SARS-CoV-2-induced pulmonary fibrosis.

COVID-19 patients can develop clinical and histopathological features associated with fibrosis, but the pathogenesis of fibrosis remains poorly understood. CD147 has been identified as a universal receptor for SARS-CoV-2 and its variants, which could initiate COVID-19-related cytokine storm. Here, we systemically analyzed lung pathogenesis in SARS-CoV-2- and its delta variant-infected humanized CD147 transgenic mice. Histopathology and Transmission Electron Microscopy revealed inflammation, fibroblast expansion and pronounced fibrotic remodeling in SARS-CoV-2-infected lungs. Consistently, RNA-sequencing identified a set of fibrosis signature genes. Furthermore, we identified CD147 as a crucial regulator for fibroblast activation induced by SARS-CoV-2. We found conditional knockout of CD147 in fibroblast suppressed activation of fibroblasts, decreasing susceptibility to bleomycin-induced pulmonary fibrosis. Meplazumab, a CD147 antibody, was able to inhibit the accumulation of activated fibroblasts and the production of ECM proteins, thus alleviating the progression of pulmonary fibrosis caused by SARS-CoV-2. In conclusion, we demonstrated that CD147 contributed to SARS-CoV-2-triggered progressive pulmonary fibrosis and identified CD147 as a potential therapeutic target for treating patients with post-COVID-19 pulmonary fibrosis.

CD147-specific chimeric antigen receptor T cells effectively inhibit T cell acute lymphoblastic leukemia.

T cell acute lymphoblastic leukemia (T-ALL) is invasive and heterogeneous, and existing therapies are sometimes unsuccessful. Chimeric antigen receptor (CAR) T cell therapy is a breakthrough tumor treatment method, particularly for B cell acute lymphoblastic leukemia. We found that CD147 was highly expressed in tumor T cells of T-ALL patients and T cell lymphoma. Therefore, CD147-CAR T cells that contain a humanized single-chain variable fragment targeting human CD147 and a second-generation CAR frame were constructed for treating T-ALL. CD147-CAR T cells were able to maintain a healthy proliferation rate, preserving a subset of CD62L+/CCR7+ memory T cells. CD147-CAR T cells showed a potent anti-tumor activity against human T-ALL cell line and T-ALL blasts, releasing high level of cytokines in the process. However, CD147-CAR T cells exhibited potential safety toward human normal cells and CD147-deficent cells. NOD/ShiLtJGpt-Prkdcem26Cd52Il2rgem26Cd22/Gpt mice were used to establish a T-ALL xenograft model and CD147-CAR T cells conferred robust protection against T-ALL progression and significantly improved survival in mice. Overall, we found that CD147 is a potential antigen target of CAR T cell therapy for T-ALL.

PDGFA-associated protein 1 is a novel target of c-Myc and contributes to colorectal cancer initiation and progression.

BACKGROUND: The mechanism underlying colorectal cancer (CRC) initiation and progression remains elusive, and overall survival is far from satisfactory. Previous studies have shown that PDGFA-associated protein 1 (PDAP1) is upregulated in several cancers including CRC. Here, we aimed to identify the cause and consequence of PDAP1 dysregulation in CRC and evaluate its role as a potential therapeutic target. METHODS: Multi-omics data analysis was performed to identify potential key players in CRC initiation and progression. Immunohistochemistry (IHC) staining was applied to determine the expression pattern of PDAP1 in CRC tissues. Pdap1 conditional knockout mice were used to establish colitis and CRC mouse models. RNA sequencing, a phosphoprotein antibody array, western blotting, histological analysis, 5-bromo-2'-deoxyuridine (BrdU) incorporation assay, and interactome analysis were applied to identify the underlying mechanisms of PDAP1. A human patient-derived xenograft (PDX) model was used to assess the potential of PDAP1 as a therapeutic target. RESULTS: PDAP1 was identified as a potential key player in CRC development using multi-omics data analysis. PDAP1 was overexpressed in CRC cells and correlated with reduced overall survival. Further investigation showed that PDAP1 was critical for the regulation of cell proliferation, migration, invasion, and metastasis. Significantly, depletion of Pdap1 in intestinal epithelial cells impaired mucosal restitution in dextran sulfate sodium salt-induced colitis and inhibited tumor initiation and growth in colitis-associated cancers. Mechanistic studies showed that c-Myc directly transactivated PDAP1, which contributed to the high PDAP1 expression in CRC cells. PDAP1 interacted with the juxtamembrane domain of epidermal growth factor receptor (EGFR) and facilitated EGFR-mitogen-activated protein kinase (MAPK) signaling activation, which resulted in FOS-related antigen 1 (FRA-1) expression, thereby facilitating CRC progression. Notably, silencing of PDAP1 could hinder the growth of patient-derived xenografts that sustain high PDAP1 levels. CONCLUSIONS: PDAP1 facilitates mucosal restitution and carcinogenesis in colitis-associated cancer. c-Myc-driven upregulation of PDAP1 promotes proliferation, migration, invasion, and metastasis of CRC cells via the EGFR-MAPK-FRA-1 signaling axis. These findings indicated that PDAP1 inhibition is warranted for CRC patients with PDAP1 overexpression.

CD147 supports paclitaxel resistance via interacting with RanBP1.

Though the great success of paclitaxel, the variable response of patients to the drug limits its clinical utility and the precise mechanisms underlying the variable response to paclitaxel remain largely unknown. This study aims to verify the role and the underlying mechanisms of CD147 in paclitaxel resistance. Immunostaining was used to analyze human non-small-cell lung cancer (NSCLC) and ovarian cancer tissues. RNA-sequencing was used to identify downstream effectors. Annexin V-FITC/propidium iodide and terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) staining were used to detect apoptosis. Co-immunoprecipitation (Co-IP), fluorescence resonance energy transfer (FRET) and surface plasmon resonance (SPR) were performed to determine protein interactions. Fluorescence recovery after photobleaching (FRAP) was performed to measure the speed of microtubule turnover. Xenograft tumor model was established to evaluate sensitivity of cancer cells to paclitaxel in vivo. In vitro and in vivo assays showed that silencing CD147 sensitized the cancer cells to paclitaxel treatment. CD147 protected cancer cells from paclitaxel-induced caspase-3 mediated apoptosis regardless of p53 status. Truncation analysis showed that the intracellular domain of CD147 (CD147ICD) was indispensable for CD147-regulated sensitivity to paclitaxel. Via screening the interacting proteins of CD147ICD, Ran binding protein 1 (RanBP1) was identified to interact with CD147ICD via its C-terminal tail. Furthermore, we showed that RanBP1 mediated CD147-regulated microtubule stability and dynamics as well as response to paclitaxel treatment. These results demonstrated that CD147 regulated paclitaxel response by interacting with the C-terminal tail of RanBP1 and targeting CD147 may be a promising strategy for preventing paclitaxel resistant.

CD147 receptor is essential for TFF3-mediated signaling regulating colorectal cancer progression.

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.

Safety and efficacy of meplazumab in healthy volunteers and COVID-19 patients: a randomized phase 1 and an exploratory phase 2 trial.

Recent evidence suggests that CD147 serves as a novel receptor for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. Blocking CD147 via anti-CD147 antibody could suppress the in vitro SARS-CoV-2 replication. Meplazumab is a humanized anti-CD147 IgG2 monoclonal antibody, which may effectively prevent SARS-CoV-2 infection in coronavirus disease 2019 (COVID-19) patients. Here, we conducted a randomized, double-blinded, placebo-controlled phase 1 trial to evaluate the safety, tolerability, and pharmacokinetics of meplazumab in healthy subjects, and an open-labeled, concurrent controlled add-on exploratory phase 2 study to determine the efficacy in COVID-19 patients. In phase 1 study, 59 subjects were enrolled and assigned to eight cohorts, and no serious treatment-emergent adverse event (TEAE) or TEAE grade ≥3 was observed. The serum and peripheral blood Cmax and area under the curve showed non-linear pharmacokinetic characteristics. No obvious relation between the incidence or titer of positive anti-drug antibody and dosage was observed in each cohort. The biodistribution study indicated that meplazumab reached lung tissue and maintained >14 days stable with the lung tissue/cardiac blood-pool ratio ranging from 0.41 to 0.32. In the exploratory phase 2 study, 17 COVID-19 patients were enrolled, and 11 hospitalized patients were involved as concurrent control. The meplazumab treatment significantly improved the discharged (P = 0.005) and case severity (P = 0.021), and reduced the time to virus negative (P = 0.045) in comparison to the control group. These results show a sound safety and tolerance of meplazumab in healthy volunteers and suggest that meplazumab could accelerate the recovery of patients from COVID-19 pneumonia with a favorable safety profile.

Di-methylation of CD147-K234 Promotes the Progression of NSCLC by Enhancing Lactate Export.

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.

CD147-spike protein is a novel route for SARS-CoV-2 infection to host cells.

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.

Identification of differentially expressed genes in non-small cell lung cancer.

Lung cancer is the most common malignant tumor and the leading cause of cancer-related deaths worldwide. Because current treatments for advanced non-small cell lung cancer (NSCLC), the most prevalent lung cancer histological subtype, show limited efficacy, screening for tumor-associated biomarkers using bioinformatics reflects the hope to improve early diagnosis and prognosis assessment. In our study, a Gene Expression Omnibus dataset was analyzed to identify genes with prognostic significance in NSCLC. Upon comparison with matched normal tissues, 118 differentially expressed genes (DEGs) were identified in NSCLC, and their functions were explored through bioinformatics analyses. The most significantly upregulated DEGs were TOP2A, SLC2A1, TPX2, and ASPM, all of which were significantly associated with poor overall survival (OS). Further analysis revealed that TOP2A had prognostic significance in early-stage lung cancer patients, and its expression correlated with levels of immune cell infiltration, especially dendritic cells (DCs). Our study provides a dataset of potentially prognostic NSCLC biomarkers, and highlights TOP2A as a valuable survival biomarker to improve prediction of prognosis in NSCLC.

Hypo-phosphorylated CD147 promotes migration and invasion of hepatocellular carcinoma cells and predicts a poor prognosis.

PURPOSE: 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. METHODS: 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. RESULTS: 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. CONCLUSIONS: 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.

Combination of CALR and PDIA3 is a potential prognostic biomarker for non-small cell lung cancer.

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.

Identification and localization of xylose-binding proteins as potential biomarkers for liver fibrosis/cirrhosis.

In our recent study, we found that the expression levels of total xylose-binding proteins (XBPs) were up-regulated significantly in activated hepatic stellate cells (HSCs); however, the denomination, distribution, and function of the XBPs were uncharted. Herein, 70 XBPs from activated HSCs and 64 XBPs from quiescent HSCs were isolated, identified and annotated. A total of 30 XBPs were up-regulated (all fold change ≥ 1.5, p ≤ 0.05) and 14 XBPs were down-regulated (all fold change ≤ 0.67, p ≤ 0.05) in the activated HSCs. The XBPs were localized at the cytoplasm and cytoplasmic membrane in HSCs and cirrhotic liver tissues by cy/histochemistry. The XBPs (i.e. PDIA6 and CFL2) responsible for the regulation of protein binding were up-regulated and those responsible for the regulation of catalytic activity (i.e. TUBB and MX1) were up-regulated in the activated HSCs. 2 candidates (i.e. PDIA6 and APOA1) were then selected for further verification in the sera of patients with HBV-induced chronic hepatitis/cirrhosis using western blotting and serum microarrays. PDIA6 showed a higher discrimination (Area Under Curves, AUCs = 0.8985, p < 0.0001) relative to APOA1 (AUCs = 0.8738, p < 0.0001) in the sera of patients as biomarker candidate. In conclusion, the precision alteration of the XBPs associated with pathological changes in HSCs during liver fibrosis/cirrhosis may provide pivotal information needed to discover potential glycan-binding protein-related biomarkers for diagnosis of liver fibrosis/cirrhosis and for development of new anti-fibrotic strategies.

Characterization and sub-cellular localization of GalNAc-binding proteins isolated from human hepatic stellate cells.

Although the expression levels of total GalNAc-binding proteins (GNBPs) were up-regulated significantly in human hepatic stellate cells (HSCs) activated with transforming growth factor-ß1(TGF-ß1), yet little is known about the precise types, distribution and sub-cellular localization of the GNBPs in HSCs. Here, 264 GNBPs from the activated HSCs and 257 GNBPs from the quiescent HSCs were identified and annotated. A total of 46 GNBPs were estimated to be significantly up-regulated and 40 GNBPs were estimated to be significantly down-regulated in the activated HSCs. For example, the GNBPs (i.e. BTF3, COX17, and ATP5A1) responsible for the regulation of protein binding were up-regulated, and those (i.e. FAM114A1, ENO3, and TKT) responsible for the regulation of protein binding were down-regulated in the activated HSCs. The motifs of the isolated GNBPs showed that Proline residue had the maximum preference in consensus sequences. The western blotting showed the expression levels of COX17, and PRMT1 were significantly up-regulated, while, the expression level of CLIC1(B5) was down-regulated in the activated HSCs and liver cirrhosis tissues. Moreover, the GNBPs were sub-localized in the Golgi apparatus of HSCs. In conclusion, the precision alteration of the GNBPs referred to pathological changes in liver fibrosis/cirrhosis may provide useful information to find new molecular mechanism of HSC activation and discover the biomarkers for diagnosis of liver fibrosis/cirrhosis as well as development of new anti-fibrotic strategies.

microRNA-146a inhibits cancer metastasis by downregulating VEGF through dual pathways in hepatocellular carcinoma.

UNLABELLED: Growing evidence indicates that miR-146a is involved in carcinogenesis and tumor progression in several human malignancies. However, the molecular details underlying miR-146a mediated regulation of its target genes and its precise biological function in cancer, especially in hepatocellular carcinoma (HCC) remains unclear. METHODS: The expression levels of genes including miR-146a, APC, VEGF and HAb18G were examined in HCC cell lines and patient specimens were compared with control levels using quantitative reverse transcription-PCR. The functions of miR-146a and HAb18G in migration/invasion and liver metastasis formation were determined by transwell and spleen injection assays, respectively. miR-146a related genes were determined by PCR array. The potential regulatory targets of miR-146a were determined by bioinformatics and prediction tools, correlation with target protein expression, and luciferase reporter assay. DNA methylation status of miR-146a promoter were performed by PCR analysis of bisulfite-modified genomic DNA. RESULTS: We demonstrated that miR-146a expression was markedly downregulated in hepatoma cells and hepatoma tissues compared to immortalized normal liver epithelial cells and normal hepatic tissues. DNA methylation of miR-146a promoter correlated with its downexpression and with liver cancer metastasis. The restoration of miR-146a dramatically suppressed HCC cell invasion and metastasis by repressing VEGF expression through upregulating APC, which inhibits ß-catenin accumulation in nucleus, and downregulating NF-κB p65 by targeting HAb18G. In human HCC, miR-146a expression was negative correlated with increased HAb18G, VEGF, NF-κB p65 and beneficial prognosis. CONCLUSION: This study identified a novel target of miR-146a and defined miR-146a as a crucial tumor suppressor in human HCC that acts through multiple pathways and mechanisms to suppress HCC invasion or metastasis.

A chimeric antibody targeting CD147 inhibits hepatocellular carcinoma cell motility via FAK-PI3K-Akt-Girdin signaling pathway.

CD147 is expressed at low levels in normal tissues but frequently highly expressed in a wide range of tumor types such as lung, breast, and liver and therefore it is a potentially unique therapeutic target for these diverse tumor types. We previously generated a murine antibody HAb18 which suppresses matrix met al.loproteinase-2 and matrix metalloproteinase-9 secretion, attenuates cell invasion by blocking the CD147 molecule in tumor cells. Here, we generated a chimeric antibody containing the variable heavy and variable light chains of murine HAb18 and the constant regions of human IgG1γ1 and human κ chain as a potential therapeutic agent (designated cHAb18). Quantitative measurement of cHAb18 antibody affinity for antigen CD147 with surface plasmon resonance showed the equilibrium dissociation constant KD was 2.66 × 10(-10) mol/L, similar to that of KD 2.73 × 10(-10) mol/L for murine HAb18. cHAb18 induced antibody-dependent cell-mediated cytotoxicity in two hepatocellular carcinoma cell lines, SMMC-7721 and Huh-7 cells. It inhibited cancer invasion and migration in hepatocellular carcinoma cells by specifically blocking CD147. Except for the depression of matrix metalloproteinase-2 and matrix metalloproteinase-9 expressions, cHAb18 antibody suppressed cell motility by rearrangement of actin cytoskeleton, which was probably induced by decreasing the phosphorylation of focal adhesion kinase, phosphatidylinositide-3 kinase (PI3K), Akt, and Girdin in the integrin signaling pathway. In an orthotopic model of hepatocellular carcinoma in BALB/c nude mice, cHAb18 treatment effectively reduced the tumor metastasis in liver and prolonged the survival. These findings reveal new therapeutic potential for cHAb18 antibody targeting CD147 on tumor therapy.

Full-length soluble CD147 promotes MMP-2 expression and is a potential serological marker in detection of hepatocellular carcinoma.

BACKGROUND: As a surface glycoprotein, CD147 is capable of stimulating the production of matrix metalloproteinases (MMPs) from neighboring fibroblasts. The aim of the present study is to explore the role of soluble CD147 on MMPs secretion from hepatocellular carcinoma (HCC) cells, and to investigate the diagnostic value of serum soluble CD147 in the HCC detection. METHODS: We identified the form of soluble CD147 in cell culture supernate of HCC cells and serum of patients with HCC, and explored the role of soluble CD147 on MMPs secretion. Serum CD147 levels were detected by the enzyme-linked immunosorbent assay, and the value of soluble CD147 as a marker in HCC detection was analyzed. RESULTS: Full length soluble CD147 was presented in the culture medium of HCC cells and serum of patients with HCC. The extracellular domain of soluble CD147 promoted the expression of CD147 and MMP-2 from HCC cells. Knockdown of CD147 markedly diminished the up-regulation of CD147 and MMP-2 which induced by soluble CD147. Soluble CD147 activated ERK, FAK, and PI3K/Akt pathways, leading to the up-regulation of MMP-2. The level of soluble CD147 in serum of patients with HCC was significantly elevated compared with healthy individuals (P < 0.001). Soluble CD147 levels were found to be associated with HCC tumor size (P = 0.007) and Child-Pugh grade (P = 0.007). Moreover, soluble CD147 showed a better performance in distinguishing HCC compared with alpha-fetoprotein. CONCLUSIONS: The extracellular domain of soluble CD147 enhances the secretion of MMP-2 from HCC cells, requiring the cooperation of membrane CD147 and activation of ERK, FAK, and PI3K/Akt signaling. The measurement of soluble CD147 may offer a useful approach in diagnosis of HCC.