Anti-tumor Effects And Signal Transduction Mechanisms Of HN From Newcastle Disease Virus And VP3 From Chicken Anaemia Virus

Cancer is a leading cause of disease-related deaths and the economic andquality-of-life impact of cancer is enormous worldwide. More than 11 million peopleare diagnosed with cancer every year. It is estimated that there will be 16 million newcases every year by 2020. Cancer causes 7 million deaths every year—or 12.5% ofdeaths worldwide. For many cancers, conventional therapies render patients free ofdisease but relapse and death remains high, particularly in advanced cancers. Thus,there is great interesting developing novel therapies that can completely removeresidual disease and prolong life. Although many novel approaches have beenadvanced in recent years, interest in cancer gene therapy has been exceptionally strong.The development of genetically engineer viruses and viral proteins that selectivelytarget various tumors resulting in minimal toxicity in the normal tissues has emergedas a potentially important approach for cancer gene therapy.To investigate the mechanisms of effect on human lung carcinoma cells SPC-A1with Hemagglutinin-neuraminidase from Newcastle disease virus and Apoptin fromfrom chicken anemia virus. The recombinant plasmid pVHN and pVVP3 wereintroduced into human lung carcinoma cells SPC-A1 by liposome-mediatedtransfection. The results showed that viability of SPC-A1 cells was decreasedsignificantly and recombinant plasmid could lead to obviously morphologicalapoptotic changes of SPC-A1 cells by introduction of pVHN and pVVP3 into SPC-A1cells for 48h. Mitochondrial transmembrane potential was decreased , ROS level of thecells was increased and Caspase-3 activity was increased, compared with empty vector(EV) control when pVHN and pVVP3 were introduced into SPC-A1 after48h .Moreover, The recombinant plasmid pVHN caused increase of MHC-I expression.The above results indicated apoptosis induced by pVHN and pVVP3 may be resultedfrom the increase of ROS level, the decrease of mitochondrial transmembranepotential and activation of Caspase-3.In this study, we analyzed the anti-tumor potential and mechanism of action ofsimultaneous Apoptin and IL-18 gene transfer in C57BL/6 mice bearing Lewis lungcarcinoma (LLC). Here we report that the growth of established tumors in miceimmunized with pVVP3 in conjunction with pVIL-18 was significantly inhibitedcompared with the growth of tumors in mice immunized with the empty vector (EV)or pVIL-18 alone. Furthermore, the immunization of mice with pVVP3 in conjunctionwith pVIL-18 elicited strong NK activity and LLC tumor-specific cytotoxic Tlymphocyte (CTL) responses in vitro. In addition, T cells from mice vaccinated withpVIL-18 or pVVP3 + pVIL-18 secreted high levels of the Th1 cytokine IL-2 andIFN-γ, indicating that the regression of tumor cells is related to a Th1-type dominantimmune response. These results demonstrate that vaccination with Apoptin togetherwith IL-18 may be a novel and powerful strategy for cancer immunotherapy.In addition, we analyzed the anti-tumor potential and mechanism of action ofrecombinant fowlpox virus vFVHN and vFVVP3 in C57BL/6 mice bearing Lewislung carcinoma (LLC). Our results showed that the growth of established tumors inmice immunized with vFVHN and vFVVP3 was significantly inhibited compared withthe growth of tumors in mice immunized with the FPV. Moreover, the immunizationof mice with vFVHN elicited strong NK activity and LLC tumor-specific cytotoxic Tlymphocyte (CTL) responses in vitro. In addition, T cells from mice vaccinated withvFVHN secreted high levels of the Th1 cytokine IL-2 and IFN-γ, indicating that theregression of tumor cells is related to a Th1-type dominant immune response.Microarray analysis on a genomic scale was used to profile changes in geneexpression accompanying human colorectal carcinoma cells HCT-8 induced by NDVHN and Apoptin. The HCT-8 cells were screened for expression of 4096 human genes,leading to the identification of 108 genes with elevated expression and 258 genes withreduced expression induced by NDV HN and 57 genes with elevated expression and136 genes with reduced expression induced by Apoptin.This differential geneexpression profile included human genes encoding proteins involved in the function ofcell cycle, cell growth and apoptosis, kinase transcription, translation and cytoskeleton,cell shape, ion channel. Furthermore, we found 5 signal transduction pathwayassociated with HN gene and 7 signal transduction pathway associated with VP3 geneby bioinformatics software and datas from KEGG,BioCarta,GenMAPP database. Theexpression ratios of partial differential expressed genes by RT-PCR were agreementwith datas from gene expression profile.In addition, DNA micrarrays on human whole genomic scale were used to profilechanges in gene expression in liver cancer cells Bel-7402 infected with recombinantfowlpox virus vFVHN and vFVVP3 for 48h. The Bel-7402 cells were screened forexpression of 22000 human genes, leading to the identification of 101 genes withelevated expression and 102 genes with reduced expression induced by vFVHN and53 genes with elevated expression and 88 genes with reduced expression induced byvFVVP3. And we found 8 signal transduction pathway associated with vFVHN and 9signal transduction pathway associated with vFVVP3 by bioinformatics software anddatas from KEGG,BioCarta,GenMAPP database. Furthermore, we found p38 MAPKpathway closely associated with vFVHN and Apaf-1, a key protein involved inintracellular pathway of apoptosis, was activated by vFVVP3. The newly identifiedgenes afford a quantitative view of the changes that accompanying Bel-7402 cellsinduced by vFVHN and vFVVP3 at genomic level, enable deeper insights into themolecular basis of anti-neoplastic mechanisms of NDV HN and Apoptin, and providean extensive list of potential molecular targets for cancer molecular therapy.