Gang Nan

Randomized Trial of [131I] Metuximab in Treatment of Hepatocellular Carcinoma After Percutaneous Radiofrequency Ablation

To assess the efficacy of combining radioimmunoconjugate [(131)I] metuximab with radiofrequency ablation (RFA) in hepatocellular carcinoma (HCC) treatment compared with RFA alone, a single-center randomized controlled trial was conducted on 127 patients with Barcelona Clinic Liver Cancer staging system (BCLC) classifications of 0-B stage. Patients received either RFA followed by [(131)I] metuximab (n = 62) or RFA alone (n = 65). The primary outcome was overall tumor recurrence. Statistical tests were two-sided. The one- and two-year recurrence rates in the combination group were 31.8% and 58.5%, whereas those in the RFA group were 56.3% and 70.9%, respectively. The median time to overall tumor recurrence was 17 months in the combination group and 10 months in the RFA group (P = .03). The RFA-[(131)I] metuximab treatment showed a greater antirecurrence benefit than RFA in the metuximab target (ie, CD147)-positive subpopulation (P = .007). [(131)I] metuximab may yield prevention of tumor recurrence after RFA.

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

BackgroundAs 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.MethodsWe 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.ResultsFull 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.ConclusionsThe 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.

Construction of Recombinant Newcastle Disease Virus Italien Strain for Oncolytic Virotherapy of Tumors

Newcastle disease virus (NDV) is a naturally oncolytic virus that has been shown to be safe and effective for cancer therapy. Tumor virotherapy using NDV emerged in the 1950s and has advanced more recently by the increased availability of reverse genetics technology. In this study, we constructed a reverse genetics system based on the virulent and oncolytic NDV Italien strain, and generated two recombinant NDVs carrying a gene encoding either enhanced green fluorescent protein or firefly luciferase. We evaluated the replication and antitumor characteristics of these viruses in vitro and in vivo. Our data showed that the insertion of exogenous reporter genes did not affect NDV replication and sensitivity to type I interferon. The recombinant NDVs kept the property of tumor-selective replication both in vitro and in vivo and strongly induced syncytium formation leading to cell death. Moreover, the recombinant NDVs significantly prolonged the survival of tumor-bearing athymic mice (p=0.017) and suppressed the loss of body weight after intratumoral injection. Taken together, our study provides a novel platform to develop recombinant oncolytic viruses based on the NDV Italien strain and shows the efficiency of recombinant NDV Italien for oncolytic virotherapy of tumors.

HAb18G/CD147 regulates vinculin-mediated focal adhesion and cytoskeleton organization in cultured human hepatocellular carcinoma cells.

Focal adhesions (FAs), integrin-mediated macromolecular complexes located at the cell membrane extracellular interface, have been shown to regulate cell adhesion and migration. Our previous studies have indicated that HAb18G/CD147 (CD147) is involved in cytoskeleton reorganization and FA formation in human hepatocellular carcinoma (HCC) cells. However, the precise mechanisms underlying these processes remain unclear. In the current study, we determined that CD147 was involved in vinculin-mediated FA focal adhesion formation in HCC cells. We also found that deletion of CD147 led to reduced vinculin-mediated FA areas (P<0.0001), length/width ratios (P<0.0001), and mean intensities (P<0.0001). CD147 promoted lamellipodia formation by localizing Arp2/3 to the leading edge of the cell. Deletion of CD147 significantly reduced the fluorescence (t 1/2) recovery times (22.7±3.3 s) of vinculin-mediated focal adhesions (P<0.0001). In cell-spreading assays, CD147 was found to be essential for dynamic focal adhesion enlargement and disassembly. Furthermore, the current data showed that CD147 reduced tyrosine phosphorylation in vinculin-mediated focal adhesions, and enhanced the accumulation of the acidic phospholipid phosphatidylinositol-4, 5-bisphosphate (PIP2). Together, these results revealed that CD147 is involved in vinculin-mediated focal adhesion formation, which subsequently promotes cytoskeleton reorganization to facilitate invasion and migration of human HCC cells.

Construction of a minigenome rescue system for Newcastle disease virus strain Italien

Newcastle disease virus (NDV) Italien, a velogenic strain, is an oncolytic virus that is considered to be a potential agent for antitumor viral therapy. We constructed three helper plasmids expressing the NP, P and L genes of NDV Italien based on the eukaryotic expression plasmid pcDNA3.1(+). The minigenome consisting of the 3′ leader and 5′ trailer regions of NDV Italien flanking a reporter gene encoding firefly luciferase was constructed to examine the efficacy of the three helper plasmids in viral genome replication and transcription. After co-transfection of BSR-T7/5 cells with the three helper plasmids and the minigenome plasmid, replication of minigenome RNA was evaluated by determining luciferase activity. In the minigenome rescue system, expression of the reporter gene was detected. Our results indicate that the three proteins NP, P, and L are correctly expressed and can assemble into a functional ribonucleoprotein complex that effectively directs the transcription of minigenome RNA.

Oncolytic Newcastle disease virus expressing chimeric antibody enhanced anti-tumor efficacy in orthotopic hepatoma-bearing mice

BackgroundOncolytic virus which arms the therapeutic gene to enhance anti-tumor activity is a prevalent strategy to improve oncovirotherapy of cancer. Newcastle disease virus (NDV) is a naturally oncolytic virus used for cancer therapy. Previously, we generated a mouse-human chimeric HAb18 antibody (cHAb18) against tumor-associated antigen CD147 and demonstrated the inhibition of invasion and migration of hepatocellular carcinoma (HCC) cells. Here, we constructed a recombinant NDV carrying intact cHAb18 gene (rNDV-18HL) based on Italien strain using a reverse genetics system.MethodRecombinant rNDV-18HL was generated using reverse genetics technology. The characteristics of virally expressed cHAb18 antibody were identified by western blot, enzyme-linked immunosorbent assay, transwell invasion assay, and surface plasmon resonance technology. The biodistribution of recombinant rNDV-18HL using orthotopic xenograft mouse model was assessed with living imaging and immunohistochemistry. Kaplan-Meier survival curves and the log-rank test were performed to analyze the anti-tumor activity of rNDV-18HL.ResultsThe cHAb18 was produced in rNDV-18HL-infected cells followed by releasing into the supernatant by cytolysis. The rNDV-18HL-encoded cHAb18 antibody kept affinity for CD147 and showed inhibiting the migration and invasion of HCC cells. Viral replication and virulence were not attenuated by the incorporation of cHAb18 gene which significantly enhanced the suppression of relict tumor cell migration. The rNDV-18HL selectively replicated in orthotopic HCC xenografts leading to cHAb18 expression in situ, which induced the tumor necrosis, reduced the intrahepatic metastasis, and prolonged the survival in mice.ConclusionsThis study provides a new strategy of arming oncolytic NDV with therapeutic antibody to enhance anti-tumor efficacy of cancer therapy.

CD147 reinforces [Ca 2+ ] i oscillations and promotes oncogenic progression in hepatocellular carcinoma

Oscillations in intracellular Ca2+ concentrations ([Ca2+]i) mediate various cellular function. Although it is known that [Ca2+]i oscillations are susceptible to dysregulation in tumors, the tumor-specific regulators of [Ca2+]i oscillations are poorly characterized. We discovered that CD147 promotes hepatocellular carcinoma (HCC) metastasis and proliferation by enhancing the amplitude and frequency of [Ca2+]i oscillations in HCC cells. CD147 activates two distinct signaling pathways to regulate [Ca2+]i oscillations. By activating FAK-Src-IP3R1 signaling pathway, CD147 promotes Ca2+ release from endoplasmic reticulum (ER) and enhances the amplitude of [Ca2+]i oscillations. Furthermore, CD147 accelerates ER Ca2+ refilling and enhances the frequency of [Ca2+]i oscillations through activating CaMKP-PAK1-PP2A-PLB-SERCA signaling pathway. Besides, CD147-promoted ER Ca2+ release and refilling are tightly regulated by changing [Ca2+]i. CD147 may activate IP3R1 channel under low [Ca2+]i conditions and CD147 may activate SERCA pump under high [Ca2+]i conditions. CD147 deletion suppresses HCC tumorigenesis and increases the survival rate of liver-specific CD147 knockout mice by regulating [Ca2+]i oscillations in vivo. Together, these results reveal that CD147 functions as a critical regulator of ER-dependent [Ca2+]i oscillations to promote oncogenic progression in HCC.

Basolateral CD147 induces hepatocyte polarity loss by E‐cadherin ubiquitination and degradation in hepatocellular carcinoma progress

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).

Disrupting CD147-RAP2 interaction abrogates erythrocyte invasion by Plasmodium falciparum

Effective vaccines against malaria caused by Plasmodium falciparum are still lacking, and the molecular mechanism of the host-parasite interaction is not fully understood. Here we demonstrate that the interaction of RAP2, a parasite-secreted rhoptry protein that functions in the parasitophorous vacuole formation stage of the invasion, and CD147 on the host erythrocyte is essential for erythrocyte invasion by P falciparum and is independent from all previously identified interactions involved. Importantly, the blockade of the CD147-RAP2 interaction by HP6H8, a humanized CD147 antibody, completely abolished the parasite invasion with both cure and preventative functions in a humanized mouse model. Together with its long half-life on human red blood cells and its safety profile in cynomolgus monkeys, HP6H8 is the first antibody that offers an advantageous approach by targeting a more conserved late-stage parasite ligand for preventing as well as treating severe malaria.

Rab22a enhances CD147 recycling and is required for lung cancer cell migration and invasion

ABSTRACT Rab22a is a member of the Ras‐related small GTPase family, which plays a key role in regulating the recycling of cargo proteins entering cells through clathrin‐independent endocytosis (CIE). Rab22a is overexpressed in different cancer types, including liver cancer, malignant melanoma, ovarian cancer and osteosarcoma. However, its oncogenic role remains unknown. In this study, we found that silencing of Rab22a suppressed the migration and invasion of lung cancer cells. Furthermore, Rab22a interacts with CD147, and knockdown of Rab22a blocks CD147 recycling and promotes CD147 degradation. Taken together, our findings indicate that Rab22a enhances recycling of CD147, which is required for lung cancer cell migration and invasion,and targeting CD147 recycling may be a rational strategy for lung cancer therapy. HighlightsKnockdown of Rab22a inhibits lung cancer cell migration and invasion.Rab22a cooperates with CD147 to mediate lung cancer cell migration and invasion.Rab22a interacts with CD147 and affects the recycling of CD147.Knockdown of Rab22a promotes CD147 ubiquitin‐proteasome degradation in a time‐dependent manner.