Lisheng Wang

Treatment of myocardial ischemia with bone marrow-derived mesenchymal stem cells overexpressing hepatocyte growth factor.

Mesenchymal stem cells could differentiate into cardiomyocytes in vitro and have been shown to reconstitute the impaired myocardium in vivo. Hepatocyte growth factor, a recognized angiogenic factor and endothelial cell chemoattractant, has been applied in the treatment of myocardial ischemia. In this study, we used a ligation model of proximal left anterior descending coronary artery of rats to evaluate the effect of mesenchymal stem cells overexpressing hepatocyte growth factor in the treatment of myocardial ischemia. Bone marrow-derived mesenchymal stem cells were isolated, expanded, characterized, and infected with adenovirus carrying human hepatocyte growth factor cDNA (Ad-HGF). Mesenchymal stem cells infected by Ad-HGF released soluble HGF protein at a high level, which was maintained at least for 2 weeks. Implantation of mesenchymal stem cells overexpressing hepatocyte growth factor into left anterior descending risk areas improved the functions of impaired myocardium, including diminishing the area of ischemia, increasing the number of capillaries, and reducing collagen content. By using the sry gene as a marker, we also demonstrated that the engrafted cells or their progeny incorporated into ischemic cardiac muscle. These results showed that treatment of myocardial ischemia with bone marrow-derived mesenchymal stem cells overexpressing hepatocyte growth factor could be a novel strategy that can both restore local blood flow and regenerate lost cardiomyocytes.

Adenoviral-mediated transfer of human wild-type p53, GM-CSF and B7-1 genes results in growth suppression and autologous anti-tumor cytotoxicity of multiple myeloma cells in vitro

Multiple myeloma (MM) remains incurable despite the use of high-dose chemotherapy and stem cell transplantation. However, immunotherapy is expected to offer long-term disease control, or even possibly a cure. We have previously demonstrated the suppressive effect of a recombinant adenovirus carrying human wild-type p53, granulocyte–macrophage colony-stimulating factor, and B7-1 genes (Ad-p53/GM-CSF/B7-1) on the growth of laryngeal cancer cells. In the present study, we evaluated the effects of an Ad-p53/GM-CSF/B7-1-modified myeloma cell vaccine strategy aimed to induce apoptosis and to augment the immunogenicity of MM cells. Both MM cell lines and purified primary myeloma cells were infected with Ad-p53/GM-CSF/B7-1. High expression levels of these three genes were confirmed separately by Western blot, enzyme-linked immunosorbent assay (ELISA), and flow cytometry. When wild-type p53, GM-CSF and B7-1 genes were introduced, the growth of MM cells was inhibited via enhanced apoptosis and the immunogenicity of tumor cells was augmented. The combinatorial effect of these three genes on inducing cytotoxic T lymphocytes (CTLs) was more evident than that of p53 individually or any combinations of two (p53 plus GM-CSF or p53 plus B7-1). Furthermore, significant proliferation of autologous peripheral blood lymphocytes (PBLs) and specific cytotoxicity against autologous primary MM cells were induced in vitro. These results suggest that myeloma cell vaccination co-transferred with p53, GM-CSF and B7-1 genes may be a promising immunotherapeutic approach against MM.

Gene Therapy for Human Nasopharyngeal Carcinoma by Adenovirus–Mediated Transfer of Human p53, GM-CSF, and B7-1 Genes in a Mouse Xenograft Tumor Model

Incidence of nasopharyngeal carcinoma (NPC) remains high in endemic regions. Prevention of tumor recurrences and metastases is a crucial approach to improve therapeutic outcome in NPC patients. In this study, we investigated the effects of the cotransfer of the tumor suppressor gene, p53, in combination with the immunostimulatory genes, GM-CSF and B7-1, on tumor regression and subsequent tumor recurrence. We constructed a recombinant adenovirus carrying human wild-type p53, granulocyte-macrophage colony-stimulating factor (GM-CSF), and B7-1 genes (Ad-p53/GM-CSF/B7-1), which mediated high-level expression of these three genes in NPC CNE-1 cells. Ad-p53/GM-CSF/B7-1 infection inhibited the growth of CNE-1 cells and induced tumor-specific cytotoxic T-lymphocytes (CTLs) in vitro. In CNE-1 xenograft tumor models in huPBL-nonobese diabetic/severe combined immunodeficiency (NOD/SCID) mice, an intratumoral injection of Ad-p53/GM-CSF/B7-1 resulted in a reduced tumor burden, compared to normal saline (NS) and Ad-p53 controls. Tumors in the Ad-p53/GM-CSF/B7-1 group displayed diffuse necrosis and infiltration of human T-cells. Further, the tumor occurrence of CNE-1 cell rechallenge largely decreased after the primary tumor was intratumorally injected with Ad-p53/GM-CSF/B7-1 in the HuPBL-NOD/SCID mice model. Only 2 of 8 (25%) animals in the Ad-p53/GM-CSF/B7-1 group had developed measurable tumors, which demonstrated extensive necrosis and much more human T-cell infiltration, compared to 5 of 7 (71%) in the NS and Ad-p53 groups. Therefore, the adenovirus-mediated introduction of p53, GM-CSF, and B7-1 genes could improve local control and prevent the recurrence or metastases of NPC tumors, which suggests a potential therapeutic value in NPC treatment.

Notch signaling stimulates osteogenic differentiation of human bone marrow-derived mesenchymal stem cells

Notch signaling is one of the most important pathways mediating cell determination and differentiation. In this study, the roles of Notch signal in the regulation of osteogenic differentiation of human bone marrow mesenchymal stem cells (hMSCs) were investigated. The expression of Notchl, Jaggedl and DTX1 detected by reverse transcription polymerase chain reaction (RT-PCR) suggested that Notch signal might exhibit a physiological regulatory role in the differentiation of MSCs. Constitutive expression of the intracellular domain of Notchl (ICN), the active form of Notchl protein, can activate Notch signal in cells without ligands’ binding. hMSCs were isolated, expanded, and infected with retrovirus carrying green fluorescent protein (GFP) gene orICN. Overexpression of ICN in hMSCs resulted in enhanced osteogenic differentiation induced by dexamethasone (Dex), which was characterized by an increase of cellular alkaline phosphatase (ALP) activity and calcium deposition. These results indicate that Notch stimulates differentiation of MSCs into osteoblasts.

Hepatocyte growth factor enhances the inflammation-alleviating effect of umbilical cord-derived mesenchymal stromal cells in a bronchiolitis obliterans model.

BACKGROUND AIMSnSpecific and effective therapy for prevention or reversal of bronchiolitis obliterans (BO) is lacking. In this study, we evaluated the therapeutic effect of hepatocyte growth factor (HGF) gene modified mesenchymal stromal cells (MSCs) on BO.nnnMETHODSnA mouse model of experimental BO was established by subcutaneously transplanting the tracheas from C57BL/6 mice into Balb/C recipients, which were then administered saline, Ad-HGF-modified human umbilical cord-MSCs (MSCs-HGF) or Ad-Null-modified MSCs (MSCs-Null). The therapeutic effects of MSCs-Null and MSCs-HGF were evaluated by using fluorescence-activated cell sorting (FACS) for lymphocyte immunophenotype of spleen, enzyme-linked immunosorbent assay (ELISA) and real-time polymerase chain reaction (rt-PCR) for cytokine expression, and histopathological analysis for the transplanted trachea.nnnRESULTSnThe histopathologic recovery of allograft tracheas was improved significantly after MSCs-Null and MSCs-HGF treatment and the beneficial effects were particularly observed in MSCs-HGF-treated mice. Furthermore, the allo-transplantation-induced immunophenotype disorders of the spleen, including regulatory T (Treg), T helper (Th)1, Th2 and Th17, were attenuated in both cell-treated groups. MSCs-HGF treatment reduced expression and secretion of inflammation cytokines interferon-gamma (IFN-γ), and increased expression of anti-inflammatory cytokine interleukin (IL)-4 and IL-10. It also decreased the expression level of the profibrosis factor transforming growth factor (TGF)-β.nnnCONCLUSIONnTreatment of BO with HGF gene modified MSCs results in reduction of local inflammation and promotion in recovery of allograft trachea histopathology. These findings might provide an effective therapeutic strategy for BO.

589. SENP1 Knockdown Inhibits Hepatocyte Growth Factor-Induced Migration and Epithelial-Mesenchymal Transition of Hepatocellular Carcinoma

The hepatocyte growth factor (HGF)/c-Met signaling aberrations are implicated in the pathogenesis and progress of hepatocellular carcinoma (HCC). However, the epigenetic regulators and their roles in modulating HGF-induced epithelial-mesenchymal transition (EMT), invasion and metastasis of HCC cells are less explored. SUMO/sentrin specific protease 1 (SENP1) is the cysteine protease that regulates SUMO pathways by deconjugating sumoylated proteins. Using real-time PCR we identified increased expression of SENP1 and c-Met in HCC tumors compared to adjacent noncancerous tissues (p<0.05, n=20). We further demonstrated that SENP1 overexpression is associated with HGF/c-Met signals in HCC. Treatment of HCC cells with HGF results in upregulation of SENP1 in a stat5 dependent manner. To explore the role of SENP1 in regulation of characteristics of HCC cells, we knocked down SENP1 in HCC cells lines using lentiviral vectors pLKO. 1-GFP-Senp1-shRNA. HCC-LM3 cells transduced with this vector demonstrated 77% decreased expression of SENP1 compared to cells transduced with a control vector. Lentivirus-mediated SENP1 knockdown triggers apoptosis (from control with 7.68% to Senp1 shRNA with 20.4%), cell cycle arrest and inhibits proliferation (80.6% inhibition, p<0.01) of HCC cells. SENP1 silence reduces HGF-induced migration of HCC cells (66.7% inhibition, p<0.01). Importantly, SENP1 inhibition increases E-cadherin and ZO-1 expression, and decrease fibronectin and N-cadherin expression in HCC cells. A series of transcription factors are involved in regulation of EMT processes. Zeb1 is a zinc finger transcription factor which induces an EMT and confers a metastatic phenotype on carcinomas. We predicted the sumoylation sites of Zeb1 by using a site-specific predictor of SUMOsp 2.0. This prediction was further validated by using Zeb-1 immunoprecipitation and Sumo2 antibody blot. HGF treatment also induced the expression of zeb1. SENP1 knockdown increased Zeb1 desumoylation, leading to reduce its protein level in HCC cells.Our results indicate that SENP1 is frequently over-expressed and associated with HGF/C-met in HCC. SENP1 plays a key role in HGF-induced proliferation, migration and epithelial-mesenchymal transition, suggesting it may be a potential new therapeutic target for HCC.

254. Hepatocyte Growth Factor Gene Modification Enhances the Inflammation-Alleviating Effect of Umbilical Cord Derived Mesenchymal Stem Cells in a Bronchiolitis Obliterans Model

BACKGROUNDS: Bronchiolitis obliterans is a serious, steadily, noninfectious, and fatal pulmonary complication. Currently specific and effective therapeutics for prevention or reversal of bronchiolitis obliterans is lacking. In this study, we evaluated the therapeutic effect of hepatocyte growth factor (HGF) gene modified mesenchymal stem cells (MSCs) on bronchiolitis obliterans.METHODS: A mouse model of experimental bronchiolitis obliterans was established by subcutaneously transplanting the tracheas from C57BL/6 mice into Balb/C recipients. These model mice were administered saline, Ad-HGF-modified human umbilical cord-MSCs (MSCs-HGF) or Ad-Null-modified MSCs (MSCs-Null). The distribution of the transplanted cells was detected by using real-time PCR (rt-PCR). The therapeutic effects of MSCs-Null and MSCs-HGF were evaluated by using FACS for lymphocyte immunophenotype of spleen, ELISA and rt-PCR for cytokine expression, and histopathological analysis for the transplanted trachea.RESULTS: The administrated MSCs mainly distributed in the transplanted trachea, blood, liver and lung of the recipients; HGF gene modification could enhance the engraftment of MSCs. The histopathological recovery of allografts tracheas was improved significantly after MSCs-Null and MSCs-HGF treatment and the beneficial effects were particularly observed in MSCs-HGFtreated mice. Furthermore, the allo-transplantation induced immunophenotype disorders of the spleen cells, including Treg, Th1, Th2 and Th17 cells, were attenuated in both cell treated groups. MSCs-HGF treatment reduced expression and secretion of inflammation cytokines interferon-gamma and increased expression of anti-inflammatory cytokine IL-4 and IL-10. It also decreased the expression level of the profibrosis factor transforming growth factor-beta.b.CONCLUSIONS: Treatment of bronchiolitis obliterans with HGF gene modified MSCs results in reduction of local inflammation and promotion in recovery of allografts tracheas histopathology in a mouse model. These findings might provide an effective therapeutic strategy for bronchiolitis obliterans.