Jun-Nian Zheng

Xuzhou Medical College, Tongshan, Jiangsu Sheng, China

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Publications (32)66.51 Total impact

  • Article: A dual-regulated oncolytic adenovirus expressing interleukin-24 sensitizes melanoma cells to temozolomide via the induction of apoptosis.
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    ABSTRACT: Malignant melanoma is one of the most lethal and aggressive human malignancies. Suppressed apoptosis and extraordinary invasiveness are the distinctive features that contribute to malignant melanoma. The alkylating agent temozolomide (TMZ) is one of the most effective single chemotherapeutic agents for patients with malignant melanoma, but resistance develops quickly and with high frequency. We constructed a dual-regulated oncolytic adenovirus expressing interleukin 24 (IL-24) gene (Ki67-ZD55-IL-24) by utilizing the Ki67 promoter to replace the native viral promoter of E1A gene. We investigated whether a combination of Ki67-ZD55-IL-24-mediated gene virotherapy and chemotherapy using TMZ produces increased cytotoxicity against human melanoma cells via the induction of apoptosis. Our data indicate that this novel strategy thus holds promising potentials for further developing an effective approach to treat malignant melanoma.
    Tumor Biology 02/2013; · 1.94 Impact Factor
  • Article: Function and mechanism by which interferon regulatory factor-1 inhibits oncogenesis.
    Fei-Fei Chen, Guan Jiang, Kerui Xu, Jun-Nian Zheng
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    ABSTRACT: The present review focuses on recent advances in the understanding of the molecular mechnisms by which interferon regulatory factor (IRF)-1 inhibits oncogenesis. IRF-1 is associated with regulation of interferon α and β transcription. In addition, numerous clinical studies have indicated that IRF-1 gene deletion or rearrangement correlates with development of specific forms of human cancer. IRF-1 has been revealed to exhibit marked functional diversity in the regulation of oncogenesis. IRF-1 activates a set of target genes associated with regulation of the cell cycle, apoptosis and the immune response. The role of IRF-1 in the regulation of various types of human tumor has important implications for understanding the susceptibility and progression of cancer. In addition, an improved understanding of the role of IRF-1 in the pathological processes that lead to human malignant diseases may aid development of novel therapeutic strategies.
    Oncology letters 02/2013; 5(2):417-423. · 0.11 Impact Factor
  • Article: EXPRESSION, PURIFICATION, AND CHARACTERIZATION OF RGD-mda-7, A HIS-TAGGED mda-7/IL-24 MUTANT PROTEIN.
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    ABSTRACT: RGD peptide (Arg-Gly-Asp tripeptide) binds to integrin αVβ(3) and αVβ(5), which is selectively expressed in tumor neovasculature and on the surface of some tumor cells. Some studies showed that coupling the RGD peptides to anticancer drugs yielded compounds with increased efficiency against tumors and lowered toxicity to normal tissues. The melanoma differentiation-associated gene-7/interleukin-24 gene (mda-7/IL-24) is a novel tumor-suppressor/cytokine gene that exhibits potent tumor-suppressive activity without damaging normal cells. To enhance the antitumor effect, we inserted a glycine residue into the wild type (mda-7/IL-24) between (164)Arg and (165)Asp to form a RGD peptide, named RGD-mda-7, then expressed RGD-mda-7 in Escherichia coli. Herein, we describe the expression and purification of RGD-mda-7. We detected the characterizations of immunostimulatory activity, tumor targeting, potent cytopathic effect, and apoptosis inducing exploited by RGD-mda-7 in tumor cells, and also compared these characterizations with wtmda-7/IL-24. The data showed that RGD-mda-7 had more potent tumor targeting and apoptosis-inducing effects than wtmda-7/IL-24.
    Journal of Immunoassay and Immunochemistry 10/2012; 33(4):352-68. · 0.69 Impact Factor
  • Article: A conditionally replicating adenovirus carrying interleukin-24 sensitizes melanoma cells to radiotherapy via apoptosis.
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    ABSTRACT: Combinatorial therapy is the current trend of the development of novel cancer treatments due to the high heterogenous nature of solid tumors. In this study, we investigated the effects of the combined use of a conditionally replicating adenovirus carrying IL-24 (ZD55-IL-24) and radiotherapy on the proliferation and apoptosis of melanoma A375 cells in vitro and in vivo. Compared with either agent used alone, ZD55-IL-24 combined with radiotherapy significantly inhibited cell proliferation, accompanied with increased apoptosis. Radiotherapy did not affect the expression of IL-24 and E1A of ZD55-IL-24-treated cells, but increased the expression of Bax, promoted the activation of caspase-3, while decreasing Bcl-2 levels. Thus, this synergistic effect of ZD55-IL-24 in combination with radiotherapy provides a novel strategy for the development of melanoma therapies, and is a promising approach for further clinical development.
    Molecular oncology 05/2012; 6(4):383-91. · 4.10 Impact Factor
  • Article: nNOS downregulation attenuates neuronal apoptosis by inhibiting nNOS-GluR6 interaction and GluR6 nitrosylation in cerebral ischemic reperfusion.
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    ABSTRACT: Glutamate receptor 6 (GluR6) is well documented to play a pivotal role in ischemic brain injury, which is mediated by the GluR6·PSD95·MLK3 signaling module and subsequent c-Jun N-terminal kinase (JNK) activation. Our recent studies show that GluR6 is S-nitrosylated in the early stages of ischemia-reperfusion. NO (Nitric Oxide) is mainly generated from neuronal nitric oxide synthase (nNOS) in cerebral neurons during the early stages of reperfusion. Here, the effect of nNOS downregulation on GluR6 S-nitrosylation and GluR6-mediated signaling was investigated in cerebral ischemia and reperfusion. Administration of nNOS oligonucleotides confirmed that GluR6 nitrosylation is induced by nNOS-derived endogenous NO and further activates the GluR6·PSD95·MLK3 signaling module and JNK signaling pathway. Moreover, this study revealed for the first time that nNOS can bind with GluR6 during ischemic reperfusion, and PSD95 is involved in this interaction. In summary, our results suggest that nNOS binds with GluR6 via PSD95 and then produces endogenous NO to S-nitrosylate GluR6 in cerebral ischemia-reperfusion, which provides a new approach for stroke therapy.
    Biochemical and Biophysical Research Communications 03/2012; 420(3):594-9. · 2.48 Impact Factor
  • Article: BRG1 expression is increased in human glioma and controls glioma cell proliferation, migration and invasion in vitro.
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    ABSTRACT: The purposes of our study were to elucidate the role of BRG1 in the development of human glioma and to determine the effect of BRG1 on glioma cell growth, migration and invasion. Using tissue microarray and immunohistochemistry, we evaluated BRG1 staining in 190 glioma tissues, 8 normal brain tissues and 8 tumor adjacent normal brain tissues. We studied glioma cell proliferative ability with reduced BRG1 expression by siRNA using CCK-8 cell proliferation assay and cell cycle analysis. We studied the role of BRG1 in glioma cell migration and invasion by cell migration assay and matrigel invasion assay. We performed western blot to detect cyclin D1, cyclin B1 and MMP-2 protein expression. We also detected MMP-2 enzyme activity by gelatin zymography. Our results showed that BRG1 expression was increased in benign tumor and malignant tumor compared with tumor adjacent normal brain tissue (P < 0.01 for both). We did not find any correlation between BRG1 expression and clinicopathological parameters. In addition, we found that knockdown of BRG1 in glioma cell lines inhibits cell growth due to the G1 phase arrest by downregulating cyclin D1. We further demonstrated that silencing of BRG1 in glioma cells inhibited the cell migration and invasion abilities, and downregulation of MMP-2 expression greatly contributed to the reduced cell invasion and migration abilities. Our data indicated that BRG1 expression is significantly increased in human glioma and it may be involved in the process of glioma cell proliferation, migration and invasion.
    Journal of Cancer Research and Clinical Oncology 02/2012; 138(6):991-8. · 2.56 Impact Factor
  • Article: Enhanced apoptosis-inducing function of MDA-7/IL-24 RGD mutant via the increased adhesion to tumor cells.
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    ABSTRACT: Melanoma differentiation-associated gene-7 (mda-7)/interleukin-24 (IL-24) has shown potent tumor cell apoptosis inducing capacity in multiple cancers. However, the apoptosis induction capacity of mda-7/IL-24 was low and directly correlated with the adhesion to tumor cells.Cell adhesion molecule integrin α(v)β(3) expressed on the surface of several types of solid tumor cells, and they bind to arginine-glycine-aspartic acid (RGD) which enhanced the adhesion to tumor cells. This rout was exploited to construct a tumor-targeting gene RGD-IL-24 which can express RGD-MDA-7/IL-24 protein that includes the cell adhesive sequence (164)Arg-(165)Gly-(166)Asp (A Glycine residue was inserted into the recombinant MDA-7/IL-24 between Arg164 and Asp165 to form a RGD motif). We successfully got the MDA-7/IL-24 mutant by overlapping polymerase chain reaction (PCR) and evaluated its therapeutic efficacy for tumor cell lines MCF-7, HeLa, HepG2, and normal human lung fibroblast (NHLF) line. And we found that the expression of pCDNA3.1/RGD-IL-24 was same to the expression of pCDNA3.1/IL-24. The RGD-IL-24 enhanced the apoptosis-inducing function in tumor cells, but not in normal cells. In tumor cell lines, the apoptosis-inducing activities of RGD-IL-24 was significantly higher than IL-24 detecting by MTT assay, Annexin V, and Hoechst 33258 analysis. Further, pCDNA3.1/RGD-IL-24 showed a significant increase in the ratio of pro-apoptotic (bax) to anti-apoptotic (bcl-2) proteins in tumor cell lines, but not in NHLF cell line. Together, these results suggest that RGD-IL-24 can enhance the apoptosis of tumor cells and may provide a promising drug in tumor therapy.
    Journal of interferon & cytokine research: the official journal of the International Society for Interferon and Cytokine Research 02/2012; 32(2):66-73. · 1.63 Impact Factor
  • Article: Analysis of human Ki-67 gene promoter and identification of the Sp1 binding sites for Ki-67 transcription.
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    ABSTRACT: Ki-67 as a cell proliferation marker is tightly associated with maintenance and regulation of the cell division. To understand the mechanism of Ki-67 gene expression and regulation, we first cloned 5'-flanking region and identified the Ki-67 core promoter. The deletion analysis and the dual luciferase reporter assay were used to locate the Ki-67 core promoter from -223 to +12 nt relative to the transcriptional initiation site, which is the TATA less, GC rich region comprised of several putative Sp1 binding sites. Compared with the hTERT promoter and Survivin promoter, the Ki-67 core promoter possessed higher transcription activity and more desirable tumor selectivity. In order to further demonstrate the contribution of transcription factor Sp1 on regulating the Ki-67 gene transcription, we confirmed three Sp1 binding sites from -170 to -145 nt, from -63 to -38 nt, and from -14 to +12 nt existed in the Ki-67 core promoter by the supershift assay. The deletion mutagenesis, together with the dual luciferase reporter assay, indicated that these Sp1 binding sites, particularly the region from -170 to -145 nt, were involved in positive regulation of the Ki-67 gene expression. Collectively, it was demonstrated that the region from -223 to +12 nt could drive the transcription of the Ki-67 gene, and the Sp1 binding site is essential to transcriptional regulation of the Ki-67 gene.
    Tumor Biology 11/2011; 33(1):257-66. · 1.94 Impact Factor
  • Article: Conditionally replicating adenoviruses carrying mda-7/IL-24 for cancer therapy.
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    ABSTRACT: Melanoma differentiation associated gene-7/interleukin-24 (mda-7/IL-24) suppresses growth and induces apoptosis in a broad range of human cancers without significant cytotoxicity to normal cells. Conditionally replicating adenoviruses (CRAds) not only have the ability to destroy cancer cells but may also be potential vectors for the expression of therapeutic genes. This review provides an overview of specifications for a novel anti-tumor approach CRAds carrying IL-24, and discusses recent progress in this field. Studies in multiple laboratories report that CRAds carrying IL-24 selectively induced apoptosis in some cancer cells, and enhanced selective toxicity to cancer cells when combined with chemotherapeutic agents. CRAds carrying IL-24 may prove a novel and effective approach for the treatment of cancers.
    Acta oncologica (Stockholm, Sweden) 10/2011; 51(3):285-92. · 2.27 Impact Factor
  • Article: RUNX3 expression is lost in glioma and its restoration causes drastic suppression of tumor invasion and migration.
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    ABSTRACT: The aim of this study is to investigate whether the expression of RUNX3 is related to the development of glioma, and the role of RUNX3 in glioma cells growth, invasion and migration. We analyzed the protein expression of RUNX3 by immunohistochemistry in 188 glioma tissues, 8 normal brain tissues and 8 tumor adjacent normal brain tissues using tissue microarray technique. We studied whether RUNX3 restoration can suppress glioma cells growth, invasion and migration by performing MTT cell proliferation assay, matrigel cell invasion assay, wound-healing assay and migration assay. We also detected MMP-2 protein expression and enzyme activity by western blot analysis and gelatin zymography. We found that RUNX3 expression was decreased in benign tumor and malignant tumor compared with tumor adjacent normal brain tissue (P < 0.01 and P < 0.05, respectively). We did not find any correlation between RUNX3 expression and clinicopathological parameters. In addition, we demonstrated that re-expression of RUNX3 in glioma cells resulted in significantly inhibited cell invasion and migration abilities. This reduced cell invasion and migration abilities were due to MMP-2 protein expression and enzyme activity suppression after RUNX3 restoration. Our data indicated that RUNX3 expression is significantly decreased in human glioma, and targeting of the RUNX3 pathway may constitute a potential treatment modality for glioma.
    Journal of Cancer Research and Clinical Oncology 09/2011; 137(12):1823-30. · 2.56 Impact Factor
  • Article: Potent antitumor effect elicited by RGD-mda-7, an mda-7/IL-24 mutant, via targeting the integrin receptor of tumor cells.
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    ABSTRACT: The melanoma differentiation-associated gene-7/interleukin-24 gene (mda-7/IL-24) is a novel tumor-suppressor/cytokine gene that exhibits potent tumor-suppressive activity without damaging normal cells. To enhance the antitumor effect, an mda-7/IL-24 mutant, RGD-mda-7, which includes the cell adhesive sequence 164Arg-165Gly-166Asp (RGD motif), was constructed and evaluated for bioactivity. RGD peptide binds to integrins α(V)β(3) and α(V)β(5), which are selectively expressed in tumor neovasculature and in the surface of some tumor cells. The wtmda-7/IL-24 and RGD-mda-7 were expressed in Escherichia coli and then purified and renatured. The immunostimulatory activity of RGD-mda-7 was assayed by stimulating peripheral blood mononuclear cells. The results suggested that the abilities of RGD-mda-7 to induce IL-6, TNF-α, and IFN-γ production were higher than wtmda-7/IL-24. Tumor targeting of RGD-mda-7 was assayed using cell adhesion experiments. The antitumor effect of the purified RGD-mda-7 on cell proliferation in vitro was evaluated using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) uptake, cell apoptosis by staining with fluorescent probes of FITC-annexin V and DAPI, and caspase-3 expression and activity. The in vitro results showed that RGD-mda-7 inhibited the proliferation of multiple tumor cell lines (Hela, ACHN, HepG2, and A549). Staining with fluorescent probes of FITC-annexin V and DAPI indicated that RGD-mda-7 could induce apoptosis more effectively in four tumor cell lines than wtmda-7/IL-24, but has no effect on normal cell line NHLF. Western blotting showed that treatment of tumor cells with RGD-mda-7 could activate apoptotic pathway by cleavage of caspase-3 as same as wtmda-7/IL-24. Further, RGD-mda-7 group showed a higher cleaved level of caspase-3, but not in NHLF cells. These results demonstrate that RGD-MDA-7 possesses more potent antitumor effects than wtmda-7/IL-24 and therefore merits further investigation in preclinical and clinical studies.
    Cancer Biotherapy & Radiopharmaceuticals 09/2011; 26(5):647-55. · 1.44 Impact Factor
  • Article: p53 regulates Ki-67 promoter activity through p53- and Sp1-dependent manner in HeLa cells.
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    ABSTRACT: The expression of the human Ki-67 protein, which is strictly associated with cell proliferation, is regulated by a variety of cellular mediators. In this study, we studied the effects of p53 on Ki-67 promoter in HeLa cells using luciferase reporter assay. The results showed that: (1) p53 inhibited Ki-67 promoter activity in a dose-dependent manner, (2) the p53-binding motifs mediated part of the transcriptional repression of Ki-67 promoter through a sequence-specific interaction with p53, (3) p53 was able to repress the Sp1-stimulated Ki-67 promoter activity, and (4) the Sp1-binding sites were responsible for the p53-mediated transcriptional repression of Ki-67 promoter. In conclusion, p53 inhibited Ki-67 promoter activity via p53- and Sp1-dependent pathways, and the interaction between p53 and Sp1 might be involved in the transcriptional regulatory mechanisms.
    Tumor Biology 05/2011; 32(5):905-12. · 1.94 Impact Factor
  • Article: The effect of methylated oligonucleotide targeting Ki-67 gene in human 786-0 renal carcinoma cells.
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    ABSTRACT: To investigate the effect of methylated oligonucleotide (MON) targeting Ki-67 promoter on the expression of Ki-67 gene and the proliferation and apoptosis of the human 786-0 renal carcinoma cells, human 786-0 cells were transfected with MON. The activity of Ki-67 promoter was detected by dual-luciferase reporter assay system. Among the five methylated oligonucleotides (MON(1)-MON(5)), MON(4) is the best excellent one in the inhibition of the Ki-67 promoter activity. The activity of Ki-67 promoter is decreased to 77.88% in 40-nM group, 50.07% in 80-nM group, 35.63% in 120-nM group, 26.09% in 160-nM group, and 16.98% in 200-nM group compared with 0-nM group. The activity of Ki-67 promoter in MON group is decreased to 61.96% at 8 h, 48.93% at 12 h, 15.97% at 24 h, 26.00% at 36 h, 35.01% at 48 h, 46.08% at 72 h, and 66.12% at 96 h compared with pGLBK235 group. These results show that the effect of MON is time- and dose-dependent. The activity of Ki-67 in MON group is decreased to 16.73% compared with pGLBK235 group, while the control groups have no significant difference. The expression of Ki-67 gene in 786-0 cells was detected by RT-PCR and immunohistochemistry, respectively. The expression of Ki-67 mRNA is decreased to 61.04% and that of Ki-67 protein is decreased to 32.07% in MON group compared with the blank group. The proliferation of 786-0 cells was determined by WST-8. The cell proliferation in MON group is decreased to 61.02% at 24 h, 73.78% at 48 h, 79.72% at 72 h, and 91.53% at 96 h compared with the blank group. The cell apoptosis was measured by annexin V and propidium iodide. The number of apoptosis cells in MON group is 2.42 times of that in the blank group at earlier period and 2.57 times at mid-anaphase. We detected the effect of MON on the expression of bax and p53 by Western blot. Compared with the blank group, the expression of bax protein in MON group is increased by 66.12%, while the expression of p53 is decreased to 67.31%. Our study demonstrates that the methylated oligonucleotide targeting Ki-67 promoter has a remarkable effect on the inhibition of Ki-67 expression and the proliferation of the human 786-0 renal carcinoma cells and can induce apoptosis of the 786-0 cells.
    Tumor Biology 05/2011; 32(5):863-72. · 1.94 Impact Factor
  • Article: A novel approach to overcome temozolomide resistance in glioma and melanoma: Inactivation of MGMT by gene therapy.
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    ABSTRACT: Malignant glioma is the most common primary brain tumor. Malignant melanoma is the most malignant of skin tumor. The two malignancies are poorly responsive to conventional treatment regimens such as chemotherapy. Temozolomide (TMZ) is a DNA-alkylating agent used for the treatment of glioma, astrocytoma, and melanoma. Resistance to alkylating agents such as TMZ correlates with increased expression of DNA repair protein O6-methylguanine-DNA methyltransferase (MGMT). Several studies in animal models have demonstrated that decreasing MGMT level with gene therapy could overcome TMZ resistance and enhance tumor cell death. In the present review, we provide an overview of recent advances in this field.
    Biochemical and Biophysical Research Communications 02/2011; 406(3):311-4. · 2.48 Impact Factor
  • Article: Identification of HLA-A*0201-restricted cytotoxic T lymphocyte epitope from proliferating cell nuclear antigen.
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    ABSTRACT: Peptide-based immunotherapy strategies appear promising as an approach to successfully induce an antitumor immune response and prolong survival in patients with various cancers. Protein antigens and their specific epitopes are formulation targets for anti-tumor vaccines. Bioinformatical approaches to predict major histocompatibility complex binding peptides can facilitate the resource-consuming effort of T cell epitope identification. Proliferating cell nuclear antigen including Ki-67 and PCNA, associated with the proliferation process of the cell, seems to be an attractive new target for tumor-specific immunotherapy. In this study, we predicted seven HLA-A*0201-restricted CTL candidate epitope of Ki-67 and eight epitope of PCNA by computer algorithm SYFPEITHI, BIMAS, and IEDB_ANN. Subsequently, biological functions of these peptides were tested by experiments in vitro. We found Ki-67((280-288)) (LQGETQLLV) had the strongest binding-affinity with HLA-A*0201. Further study revealed that Ki-67((280-288)) increased the frequency of IFN-γ-producing T cells compared to a negative peptide. Because Ki-67 was broadly expressed in most advanced malignant tumors, indicating a potential anti-tumor application in the future.
    Tumor Biology 02/2011; 32(1):63-9. · 1.94 Impact Factor
  • Source
    Article: Combining conditionally replicating adenovirus-mediated gene therapy with chemotherapy: a novel antitumor approach.
    Guan Jiang, Yong Xin, Jun-Nian Zheng, Yan-Qun Liu
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    ABSTRACT: Despite significant improvements in diagnosis and innovations in the therapy of specific cancers, effective treatment of neoplastic diseases still presents major challenges. Recent studies have shown that conditionally replicating adenoviruses (CRAds) not only have the ability to destroy cancer cells but may also be potential vectors for the expression of therapeutic genes. Several studies in animal models have demonstrated that the combination of CRAds-mediated gene therapy and chemotherapy has greater therapeutic benefit than either treatment modality alone. In this review, an overview of specifications for a novel antitumor approach combining CRAd-gene therapy and chemotherapy is provided and recent progress in this field is discussed.
    International Journal of Cancer 01/2011; 129(2):263-74. · 5.44 Impact Factor
  • Article: Expression of urotensin II and its receptor in human lung adenocarcinoma A549 cells and the effect of urotensin II on lung adenocarcinoma growth in vitro and in vivo.
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    ABSTRACT: Urotensin II (UII), originally identified from fish urophysis, is a potent vasoactive peptide and an endogenous ligand for an orphan G protein-coupled receptor GPR14, now named as urotensin II receptor (UT-R). In this study, we investigated the mRNA and protein expressions of UII and its receptor (UT-R) in human lung adenocarcinoma A549 cells, and the effect of exogenous UII on the proliferation of A549 cells in vitro and in vivo. Reverse transcription-polymerase chain reaction (RT-PCR) and western blot analysis showed that both mRNAs and proteins of UII and UT-R were obviously expressed in human lung adenocarcinoma A549 cells. Immunohistochemical analysis showed that UII peptide was mainly expressed in the cyto-plasm, and UT-R protein was expressed on the cytomembrane and also in the cytoplasm. 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl tetrazolium bromide (MTT) analysis demonstrated that treatment with different concentrations of human UII (10(-9), 10(-8), 10(-7) and 10(-6) M) for 48 h significantly increased the number of A549 cells. The effect of UII at the concentration of 10(-7) M on the proliferation of A549 cells is most pronounced. Nude mice bearing human lung adenocarcinoma A549 cells treated with UII showed a significant increase in tumor volume and tumor weight compared with control group. These findings suggest that UII may contribute to the pathogenesis of human lung adenocarcinoma as an autocrine/paracrine growth stimulating factor.
    Oncology Reports 11/2010; 24(5):1179-84. · 1.84 Impact Factor
  • Article: Down-regulation of O6-methylguanine-DNA methyl transferase enhances the effect of temozolomide in melanoma cells.
    Guan Jiang, Jun-Nian Zheng, Yan-Qun Liu
    Medical Hypotheses 10/2010; 76(1):147-8. · 1.39 Impact Factor
  • Article: A critical role of Sp1 transcription factor in regulating the human Ki-67 gene expression.
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    ABSTRACT: Ki-67 plays a crucial role in cell proliferation as well as maintenance or regulation of cell division. The mechanism governing the Ki-67 gene expression remains unknown. Thus, we cloned the core promoter of the human Ki-67 gene and further investigated its transcriptional regulation. The putative Sp1 binding sites were confirmed by electrophoretic mobility shift assay together with an anti-Sp1 antibody-mediated supershift assay. Deletion mutagenesis and firefly luciferase reporter gene assay demonstrated the essential contribution of Sp1 on transcriptional activation of the Ki-67 gene. In this study, we first confirm that there are three Sp1 binding sites in the Ki-67 core promoter. Two Sp1 sites (one at position -159 to -145 nt and the other at position -14 to +12 nt) are mainly involved in transcriptional regulation of the Ki-67 gene. Overexpression of Sp1 can enhance the Ki-67 promoter activity. However, down-regulation of Sp1 expression using siRNA-Sp1 and mithramycin effectively inhibits the Ki-67 gene transcription. Our results suggest that Sp1 is essential for basal promoter activity of the human Ki-67 gene. Inhibition of the Ki-67 transcriptional activity through abolishment of Sp1 may provide the useful prospect for gene therapy.
    Tumor Biology 10/2010; 32(2):273-83. · 1.94 Impact Factor
  • Article: Oncolytic-adenovirus-expressed RNA interference for cancer therapy.
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    ABSTRACT: RNA interference (RNAi) has generated considerable excitement for its potential cancer therapeutic applications. Because of the difficulties in delivering a large amount of siRNA to cancer cells and the short half-life of siRNA, it is important to choose an efficient delivery system for transduction of siRNA into target cells. Oncolytic adenovirus offers a better platform by virtue of its high transfection efficiency and selective replication in cancer cells. This review focuses on the synergism between oncolytic adenovirus and siRNA antitumor responses, and discusses recent progresses in oncolytic-adenovirus-expressed siRNA. siRNA-expressing oncolytic adenovirus can generate a significantly enhanced antitumor effect through gene knockdown and viral oncolysis. Due to its potency and target specificity, using siRNA delivery by oncolytic adenovirus has generated much excitement and will open new avenues for treatment of human cancer.
    Expert opinion on biological therapy 09/2010; 10(9):1331-41. · 3.22 Impact Factor

Institutions

  • 2005–2013
    • Xuzhou Medical College
      • • Laboratory of Biological Cancer Therapy
      • • Research Center for Biochemistry and Molecular Biology
      Tongshan, Jiangsu Sheng, China
  • 2012
    • Nanjing Medical University
      Nanjing, Jiangsu Sheng, China
  • 2011
    • Chinese Center For Disease Control And Prevention
      Beijing, Beijing Shi, China