Phase I/II Study of EBV-LMP1 Targeted DNAzyme in Nasopharyngeal Carcinoma View Homepage


Ontology type: schema:MedicalStudy     


Clinical Trial Info

YEARS

2009-2011

ABSTRACT

The purpose of this study is to determine whether an EBV-LMP1 targeted DNAzyme is effective in radiosensitization of nasopharyngeal carcinoma in combination with standard radiation therapy. Detailed Description INTRODUCTION Nasopharyngeal carcinoma (NPC) is a serious health problems worldwide, particularly in the southern Chinese population, with an incidence rate ranging from 15 to 50 per 100 000. NPC is an epithelial malignancy with a striking racial and geographic distribution differences. High incidence rates are observed in the southeast Chinese population, and similar rates have been reported in these people wherever they have migrated, including Singapore, Taiwan, and Hong Kong. This incidence is almost 100 fold higher than in white populations. The most unique feature of NPC is its almost universal association with the infection of Epstein-Barr virus (EBV), which is the first human virus identified to be involved in the pathogenesis of several malignancies and has a particularly close association with NPC, as EBV genome can be detected in virtually all NPC cells. While radiotherapy has been the first-line treatments for NPC, radio-resistance remains a significant clinical issue for the NPC radiotherapy. Thus, there is unmet medical needs to discover and develop novel radiosensitizers for NPC therapy. EBV infection in NPC is classified as type II latent infection in which only EBV nuclear antigen-1(EBNA-1), latent membrane protein-1(LMP1), LMP2, and EBV early RNA (EBER) expressions can be detected. Among these proteins, LMP1 is thought to play a key role in the pathogenesis of NPC. As a 60kD integral membrane protein, LMP1 functions as a constitutively active tumor necrosis factor receptor (TNFR), and contributes to multiple aspects of NPC through activating a number of signaling pathways including nuclear factor NF-κB, activator protein-1(AP-1), and Janus kinase/signal transducer and activator of transcription(JAK/STAT). Activation of NF-kB or AP-1 by LMP1 has been linked to the upregulation of some cellular proteins and inhibition of apoptosis. Depending on the cell types, expression of LMP1 has been shown to play different roles in response to biological and physiological stimulus. It acts as a primary oncoprotein for human cell immortalization and is also shown as the only EBV-coded product that can transform rodent fibroblast cell line, human epithelial cells and keratinocytes. Given the critical role of viral oncoproteins in transformation and apoptosis, suppression of some viral oncoproteins would provide a sensible strategy to genetically treat NPC. Indeed, antisense oligonucleotides against LMP1 or EBNA1 have been shown to inhibit viral oncoprotein expression, induce apoptosis, and sensitize the EBV-positive cells to cytotoxic agents. Recently, some experimental studies indicated that the RNA interference against LMP1 exhibited an anti-proliferative and anti-metastasis effect in LMP1 expressing NPCs. These results suggested that EBV-encoded LMP1 may present a potential molecular target for treatment of EBV-associated carcinomas. DNAzymes are synthetic, single-stranded DNA oligonucleotides that can be engineered to bind to their complementary sequence in a target messenger RNA (mRNA) through Watson-Crick base pairing and cleave the mRNA at predetermined phosphodiester linkages. A general model for the DNAzyme has been proposed, and is known as the ''10-23'' model. A ''10-23'' DNAzyme has a catalytic domain of 15 deoxyribonucleotides, flanked by two substrate-recognition domains of seven to nine deoxyribonucleotides at each arm. In vitro analyses showed that this type of DNAzyme could effectively cleave its substrate RNA at purine: pyrimidine junctions under physiological conditions. These agents have been used in a number of in vitro and in vivo applications to inhibit the expression of their target genes and the dependent genes. Their capacity to block development of a diverse range of pathologies in animal models suggests that DNAzymes can be used as therapeutic agents. To develop EBV-LMP1 targeted DNAzymes for NPC treatment, we showed that the phosphorothioate-modified ''10-23'' DNAzymes specifically targeted at the LMP1 mRNA could significantly down-regulate the expression of LMP1 in a nasopharyngeal carcinoma cell (NPC) and affected the down-stream pathways activated by LMP1, including the NF-κB pathway. It was also demonstrated that suppression of the LMP1 expression by the LMP1-targeted DNAzyme DZ1 could enhance radiosensitivity both in vivo and vitro. Radio-resistance has been one of the impediments in clinical settings for effective cancer therapy, which is thought to be associated with multiple signaling pathways in different cancer types. ATM (ataxia telangiectasia mutated) is a nuclear 350-kDa protein kinase with a carboxylterminal phosphatidylinositol 3-kinase-like kinase domain[1]. It functions as a member of a coordinated system that detects DNA breaks; arrests the cells temporarily at G1, S, or G2 checkpoints; and activates DNA repair. Cells lacking functional ATM protein show increased sensitivity to ionizing radiation (IR) and other genotoxic events. NF-κB (nuclear factor kappa B) can activate a great number of genes involved in stress responses, inflammation, and programmed cell death (apoptosis). P50 homodimers or p50/p65 or p50/c-Rel heterodimers bind to the NF-κB DNA binding sites in the promoter regions of many stress-responsive genes, suggesting a complex gene and physiological regulation network controlled by NF-κB in stress response. The elevated basal NF-κB activity in certain cancers has been linked to tumor resistance to chemotherapy and radiation. Inhibition of NF-κB blocked the adaptive radioresistance. Our studies for the molecular mechanism of the LMP1-DNAzyme mediated radiosensitization revealed that LMP1 activated the ATM expression through the NF-κB pathway and inhibition of LMP1 expression by the DNAzyme attenuated the binding of NF-κB transcription factor to the ATM promoter. Further evidence showed that the radiosensitivity was recovered when the ATM expression was knocked down by siRNA in NPCs. Together, all our data support our hypothesis and provide solid experimental basis for the use of LMP1-targeted DNAzymes as potential radiosensitizers for treatment of the EBV-associated carcinomas. Toxicological studies in mice showed that no morbidity or mortality was observed in any of the dosing groups during the course of the study (50mg, 100mg, and 200mg/kg). All hematological values and biochemistry results from tests of hepatic and renal function were normal. No microscopic lesion that could be attributed to the modified DNAzyme oligonucleotide treatment was found in liver, spleen and kidney in any groups. After i.v. administration of 100 mg/kg DNAzyme oligonucleotide in mice, the peak plasma concentration of 24.13±2.6μg/ml was achieved. The decrease in plasma concentration of DNAzyme followed a bi-exponential pattern with initial distribution half-life (t1/2α) of 0.18±0.03 h and a terminal half-life (t1/2β) of 2.55±1.0 h, and area under the plasma concentration-time curve (AUC) was 54.17±9.1μg.h/ml. STUDY DESIGN This study will be a randomized, double-blinded and placebo controlled Phase I/II clinical trial. Forty (40) patients will be randomized to one of two groups of equal size: placebo group receiving saline by intra-tumor injection and standard radiotherapy; or DZ1 group receiving LMP1 DNAzyme (DZ1) and standard radiotherapy. The placebo group will provide the basis for assessment of safety and efficacy of DZ1. Patients receive placebo or DZ1 injection two (2) hours prior to radical radiation therapy on Monday and Thursday over seven weeks. The radical radiotherapy is given to patients 5 times per week with 2 Gy of each treatment. The entire procedure lasts seven weeks. All patients will complete the study at 104 weeks post-first injection. The patients will undergo assessment and testing every week in the first seven weeks, then every three months from the weeks 8 to week 104. The study will include evaluations of safety and tolerability: More... »

URL

https://clinicaltrials.gov/show/NCT01449942

Related SciGraph Publications

JSON-LD is the canonical representation for SciGraph data.

TIP: You can open this SciGraph record using an external JSON-LD service: JSON-LD Playground Google SDTT

[
  {
    "@context": "https://springernature.github.io/scigraph/jsonld/sgcontext.json", 
    "about": [
      {
        "id": "http://purl.org/au-research/vocabulary/anzsrc-for/2008/3053", 
        "inDefinedTermSet": "http://purl.org/au-research/vocabulary/anzsrc-for/2008/", 
        "type": "DefinedTerm"
      }, 
      {
        "id": "http://purl.org/au-research/vocabulary/anzsrc-for/2008/3142", 
        "inDefinedTermSet": "http://purl.org/au-research/vocabulary/anzsrc-for/2008/", 
        "type": "DefinedTerm"
      }
    ], 
    "description": "The purpose of this study is to determine whether an EBV-LMP1 targeted DNAzyme is effective in radiosensitization of nasopharyngeal carcinoma in combination with standard radiation therapy.\n\nDetailed Description\nINTRODUCTION Nasopharyngeal carcinoma (NPC) is a serious health problems worldwide, particularly in the southern Chinese population, with an incidence rate ranging from 15 to 50 per 100 000. NPC is an epithelial malignancy with a striking racial and geographic distribution differences. High incidence rates are observed in the southeast Chinese population, and similar rates have been reported in these people wherever they have migrated, including Singapore, Taiwan, and Hong Kong. This incidence is almost 100 fold higher than in white populations. The most unique feature of NPC is its almost universal association with the infection of Epstein-Barr virus (EBV), which is the first human virus identified to be involved in the pathogenesis of several malignancies and has a particularly close association with NPC, as EBV genome can be detected in virtually all NPC cells. While radiotherapy has been the first-line treatments for NPC, radio-resistance remains a significant clinical issue for the NPC radiotherapy. Thus, there is unmet medical needs to discover and develop novel radiosensitizers for NPC therapy. EBV infection in NPC is classified as type II latent infection in which only EBV nuclear antigen-1(EBNA-1), latent membrane protein-1(LMP1), LMP2, and EBV early RNA (EBER) expressions can be detected. Among these proteins, LMP1 is thought to play a key role in the pathogenesis of NPC. As a 60kD integral membrane protein, LMP1 functions as a constitutively active tumor necrosis factor receptor (TNFR), and contributes to multiple aspects of NPC through activating a number of signaling pathways including nuclear factor NF-\u03baB, activator protein-1(AP-1), and Janus kinase/signal transducer and activator of transcription(JAK/STAT). Activation of NF-kB or AP-1 by LMP1 has been linked to the upregulation of some cellular proteins and inhibition of apoptosis. Depending on the cell types, expression of LMP1 has been shown to play different roles in response to biological and physiological stimulus. It acts as a primary oncoprotein for human cell immortalization and is also shown as the only EBV-coded product that can transform rodent fibroblast cell line, human epithelial cells and keratinocytes. Given the critical role of viral oncoproteins in transformation and apoptosis, suppression of some viral oncoproteins would provide a sensible strategy to genetically treat NPC. Indeed, antisense oligonucleotides against LMP1 or EBNA1 have been shown to inhibit viral oncoprotein expression, induce apoptosis, and sensitize the EBV-positive cells to cytotoxic agents. Recently, some experimental studies indicated that the RNA interference against LMP1 exhibited an anti-proliferative and anti-metastasis effect in LMP1 expressing NPCs. These results suggested that EBV-encoded LMP1 may present a potential molecular target for treatment of EBV-associated carcinomas. DNAzymes are synthetic, single-stranded DNA oligonucleotides that can be engineered to bind to their complementary sequence in a target messenger RNA (mRNA) through Watson-Crick base pairing and cleave the mRNA at predetermined phosphodiester linkages. A general model for the DNAzyme has been proposed, and is known as the ''10-23'' model. A ''10-23'' DNAzyme has a catalytic domain of 15 deoxyribonucleotides, flanked by two substrate-recognition domains of seven to nine deoxyribonucleotides at each arm. In vitro analyses showed that this type of DNAzyme could effectively cleave its substrate RNA at purine: pyrimidine junctions under physiological conditions. These agents have been used in a number of in vitro and in vivo applications to inhibit the expression of their target genes and the dependent genes. Their capacity to block development of a diverse range of pathologies in animal models suggests that DNAzymes can be used as therapeutic agents. To develop EBV-LMP1 targeted DNAzymes for NPC treatment, we showed that the phosphorothioate-modified ''10-23'' DNAzymes specifically targeted at the LMP1 mRNA could significantly down-regulate the expression of LMP1 in a nasopharyngeal carcinoma cell (NPC) and affected the down-stream pathways activated by LMP1, including the NF-\u03baB pathway. It was also demonstrated that suppression of the LMP1 expression by the LMP1-targeted DNAzyme DZ1 could enhance radiosensitivity both in vivo and vitro. Radio-resistance has been one of the impediments in clinical settings for effective cancer therapy, which is thought to be associated with multiple signaling pathways in different cancer types. ATM (ataxia telangiectasia mutated) is a nuclear 350-kDa protein kinase with a carboxylterminal phosphatidylinositol 3-kinase-like kinase domain[1]. It functions as a member of a coordinated system that detects DNA breaks; arrests the cells temporarily at G1, S, or G2 checkpoints; and activates DNA repair. Cells lacking functional ATM protein show increased sensitivity to ionizing radiation (IR) and other genotoxic events. NF-\u03baB (nuclear factor kappa B) can activate a great number of genes involved in stress responses, inflammation, and programmed cell death (apoptosis). P50 homodimers or p50/p65 or p50/c-Rel heterodimers bind to the NF-\u03baB DNA binding sites in the promoter regions of many stress-responsive genes, suggesting a complex gene and physiological regulation network controlled by NF-\u03baB in stress response. The elevated basal NF-\u03baB activity in certain cancers has been linked to tumor resistance to chemotherapy and radiation. Inhibition of NF-\u03baB blocked the adaptive radioresistance. Our studies for the molecular mechanism of the LMP1-DNAzyme mediated radiosensitization revealed that LMP1 activated the ATM expression through the NF-\u03baB pathway and inhibition of LMP1 expression by the DNAzyme attenuated the binding of NF-\u03baB transcription factor to the ATM promoter. Further evidence showed that the radiosensitivity was recovered when the ATM expression was knocked down by siRNA in NPCs. Together, all our data support our hypothesis and provide solid experimental basis for the use of LMP1-targeted DNAzymes as potential radiosensitizers for treatment of the EBV-associated carcinomas. Toxicological studies in mice showed that no morbidity or mortality was observed in any of the dosing groups during the course of the study (50mg, 100mg, and 200mg/kg). All hematological values and biochemistry results from tests of hepatic and renal function were normal. No microscopic lesion that could be attributed to the modified DNAzyme oligonucleotide treatment was found in liver, spleen and kidney in any groups. After i.v. administration of 100 mg/kg DNAzyme oligonucleotide in mice, the peak plasma concentration of 24.13\u00b12.6\u03bcg/ml was achieved. The decrease in plasma concentration of DNAzyme followed a bi-exponential pattern with initial distribution half-life (t1/2\u03b1) of 0.18\u00b10.03 h and a terminal half-life (t1/2\u03b2) of 2.55\u00b11.0 h, and area under the plasma concentration-time curve (AUC) was 54.17\u00b19.1\u03bcg.h/ml. STUDY DESIGN This study will be a randomized, double-blinded and placebo controlled Phase I/II clinical trial. Forty (40) patients will be randomized to one of two groups of equal size: placebo group receiving saline by intra-tumor injection and standard radiotherapy; or DZ1 group receiving LMP1 DNAzyme (DZ1) and standard radiotherapy. The placebo group will provide the basis for assessment of safety and efficacy of DZ1. Patients receive placebo or DZ1 injection two (2) hours prior to radical radiation therapy on Monday and Thursday over seven weeks. The radical radiotherapy is given to patients 5 times per week with 2 Gy of each treatment. The entire procedure lasts seven weeks. All patients will complete the study at 104 weeks post-first injection. The patients will undergo assessment and testing every week in the first seven weeks, then every three months from the weeks 8 to week 104. The study will include evaluations of safety and tolerability:", 
    "endDate": "2011-09-01T00:00:00Z", 
    "id": "sg:clinicaltrial.NCT01449942", 
    "keywords": [
      "LMP1", 
      "nasopharyngeal carcinoma", 
      "radiosensitization", 
      "radiation therapy", 
      "introduction", 
      "serious health problem", 
      "Chinese population", 
      "incidence rate", 
      "epithelial malignancy", 
      "geographic distribution", 
      "high incidence rate", 
      "similar rate", 
      "Singapore", 
      "Taiwan", 
      "Hong Kong", 
      "incidence", 
      "white population", 
      "unique feature", 
      "association", 
      "infection", 
      "Human Herpesvirus 4", 
      "human virus", 
      "pathogenesis", 
      "malignancy", 
      "close association", 
      "Epstein-Barr virus genome", 
      "radiotherapy", 
      "first-line treatment", 
      "resistance", 
      "clinical issue", 
      "radiosensitizers", 
      "Epstein-Barr virus infection", 
      "latent infection", 
      "nuclear antigen", 
      "EBNA-1", 
      "latent membrane protein 1", 
      "LMP2", 
      "Epstein Barr", 
      "expression", 
      "protein", 
      "key role", 
      "membrane protein", 
      "membrane protein function", 
      "Tumor Necrosis Factor Receptor", 
      "multiple aspect", 
      "signaling pathway", 
      "nuclear factor", 
      "Transcription Factor AP-1", 
      "transducer", 
      "activator", 
      "transcription", 
      "JAK/STAT", 
      "NF", 
      "latent membrane protein", 
      "Up-Regulation", 
      "cellular protein", 
      "inhibition", 
      "apoptosis", 
      "cell type", 
      "different role", 
      "physiological stimulus", 
      "oncoprotein", 
      "cell immortalization", 
      "fibroblast cell line", 
      "human epithelial cell", 
      "keratinocytes", 
      "critical role", 
      "viral oncoproteins", 
      "transformation", 
      "suppression", 
      "antisense oligonucleotides", 
      "positive cell", 
      "cytotoxic agent", 
      "experimental study", 
      "RNA interference", 
      "potential molecular target", 
      "Catalytic DNA", 
      "single-stranded DNA", 
      "complementary sequence", 
      "Messenger RNA", 
      "Base Pairing", 
      "phosphodiester", 
      "general model", 
      "Catalytic Domain", 
      "deoxyribonucleotides", 
      "substrate recognition", 
      "arm", 
      "vitro analysis", 
      "substrate RNA", 
      "purine", 
      "pyrimidine", 
      "physiological condition", 
      "agent", 
      "vitro", 
      "vivo application", 
      "target gene", 
      "gene", 
      "capacity", 
      "development", 
      "diverse range", 
      "pathology", 
      "animal model", 
      "therapeutic agent", 
      "down-stream", 
      "NF-\u03baB", 
      "Radiation Tolerance", 
      "vivo", 
      "impediment", 
      "clinical setting", 
      "effective cancer therapy", 
      "multiple signaling pathway", 
      "different cancer type", 
      "ATM", 
      "ataxia telangiectasia", 
      "protein kinase", 
      "phosphatidylinositol kinase", 
      "coordinated system", 
      "DNA break", 
      "cell", 
      "G1", 
      "G2 checkpoint", 
      "DNA repair", 
      "increased sensitivity", 
      "ionizing radiation", 
      "nuclear factor kappa", 
      "great number", 
      "stress response", 
      "inflammation", 
      "programmed cell death", 
      "homodimer", 
      "heterodimer", 
      "binding site", 
      "Genetic Promoter Region", 
      "responsive gene", 
      "complex", 
      "physiological regulation", 
      "certain cancer", 
      "tumor resistance", 
      "Drug Therapy", 
      "radiation", 
      "radioresistance", 
      "molecular mechanism", 
      "binding", 
      "transcription factor", 
      "promoter", 
      "evidence", 
      "experimental basis", 
      "toxicological study", 
      "mouse", 
      "morbidity", 
      "mortality", 
      "dosing", 
      "biochemistry", 
      "renal function", 
      "lesion", 
      "oligonucleotides", 
      "liver", 
      "spleen", 
      "kidney", 
      "i.v", 
      "Organization and Administration", 
      "plasma concentration", 
      "decrease", 
      "pattern", 
      "initial distribution", 
      "half-life", 
      "Area Under Curve", 
      "study design", 
      "placebo", 
      "Phase I/II", 
      "clinical trial", 
      "patient", 
      "equal size", 
      "placebo group", 
      "saline", 
      "injection", 
      "standard radiotherapy", 
      "assessment", 
      "safety", 
      "efficacy", 
      "Gy", 
      "Evaluation Study as Topic", 
      "tolerability"
    ], 
    "name": "Phase I/II Study of EBV-LMP1 Targeted DNAzyme in Nasopharyngeal Carcinoma", 
    "sameAs": [
      "https://app.dimensions.ai/details/clinical_trial/NCT01449942"
    ], 
    "sdDataset": "clinical_trials", 
    "sdDatePublished": "2019-03-07T15:24", 
    "sdLicense": "https://scigraph.springernature.com/explorer/license/", 
    "sdPublisher": {
      "name": "Springer Nature - SN SciGraph project", 
      "type": "Organization"
    }, 
    "sdSource": "file:///pack/app/us_ct_data_00011.json", 
    "sponsor": [
      {
        "id": "https://www.grid.ac/institutes/grid.452223.0", 
        "type": "Organization"
      }
    ], 
    "startDate": "2009-05-01T00:00:00Z", 
    "subjectOf": [
      {
        "id": "sg:pub.10.1038/sj.cgt.7700833", 
        "sameAs": [
          "https://app.dimensions.ai/details/publication/pub.1008611413", 
          "https://doi.org/10.1038/sj.cgt.7700833"
        ], 
        "type": "CreativeWork"
      }, 
      {
        "id": "sg:pub.10.1038/nrc3138", 
        "sameAs": [
          "https://app.dimensions.ai/details/publication/pub.1019467785", 
          "https://doi.org/10.1038/nrc3138"
        ], 
        "type": "CreativeWork"
      }, 
      {
        "id": "https://doi.org/10.3390/molecules15096127", 
        "sameAs": [
          "https://app.dimensions.ai/details/publication/pub.1021869764"
        ], 
        "type": "CreativeWork"
      }, 
      {
        "id": "sg:pub.10.1186/1471-2407-14-835", 
        "sameAs": [
          "https://app.dimensions.ai/details/publication/pub.1024606096", 
          "https://doi.org/10.1186/1471-2407-14-835"
        ], 
        "type": "CreativeWork"
      }, 
      {
        "id": "https://doi.org/10.1016/j.canlet.2008.02.019", 
        "sameAs": [
          "https://app.dimensions.ai/details/publication/pub.1029804240"
        ], 
        "type": "CreativeWork"
      }, 
      {
        "id": "sg:pub.10.1038/8658", 
        "sameAs": [
          "https://app.dimensions.ai/details/publication/pub.1041797087", 
          "https://doi.org/10.1038/8658"
        ], 
        "type": "CreativeWork"
      }, 
      {
        "id": "https://doi.org/10.1089/108729002761381276", 
        "sameAs": [
          "https://app.dimensions.ai/details/publication/pub.1059208060"
        ], 
        "type": "CreativeWork"
      }, 
      {
        "id": "https://app.dimensions.ai/details/publication/pub.1074695863", 
        "type": "CreativeWork"
      }, 
      {
        "id": "https://app.dimensions.ai/details/publication/pub.1077439827", 
        "type": "CreativeWork"
      }
    ], 
    "type": "MedicalStudy", 
    "url": "https://clinicaltrials.gov/show/NCT01449942"
  }
]
 

Download the RDF metadata as:  json-ld nt turtle xml License info

HOW TO GET THIS DATA PROGRAMMATICALLY:

JSON-LD is a popular format for linked data which is fully compatible with JSON.

curl -H 'Accept: application/ld+json' 'https://scigraph.springernature.com/clinicaltrial.NCT01449942'

N-Triples is a line-based linked data format ideal for batch operations.

curl -H 'Accept: application/n-triples' 'https://scigraph.springernature.com/clinicaltrial.NCT01449942'

Turtle is a human-readable linked data format.

curl -H 'Accept: text/turtle' 'https://scigraph.springernature.com/clinicaltrial.NCT01449942'

RDF/XML is a standard XML format for linked data.

curl -H 'Accept: application/rdf+xml' 'https://scigraph.springernature.com/clinicaltrial.NCT01449942'


 

This table displays all metadata directly associated to this object as RDF triples.

234 TRIPLES      16 PREDICATES      208 URIs      192 LITERALS      1 BLANK NODES

Subject Predicate Object
1 sg:clinicaltrial.NCT01449942 schema:about anzsrc-for:3053
2 anzsrc-for:3142
3 schema:description The purpose of this study is to determine whether an EBV-LMP1 targeted DNAzyme is effective in radiosensitization of nasopharyngeal carcinoma in combination with standard radiation therapy. Detailed Description INTRODUCTION Nasopharyngeal carcinoma (NPC) is a serious health problems worldwide, particularly in the southern Chinese population, with an incidence rate ranging from 15 to 50 per 100 000. NPC is an epithelial malignancy with a striking racial and geographic distribution differences. High incidence rates are observed in the southeast Chinese population, and similar rates have been reported in these people wherever they have migrated, including Singapore, Taiwan, and Hong Kong. This incidence is almost 100 fold higher than in white populations. The most unique feature of NPC is its almost universal association with the infection of Epstein-Barr virus (EBV), which is the first human virus identified to be involved in the pathogenesis of several malignancies and has a particularly close association with NPC, as EBV genome can be detected in virtually all NPC cells. While radiotherapy has been the first-line treatments for NPC, radio-resistance remains a significant clinical issue for the NPC radiotherapy. Thus, there is unmet medical needs to discover and develop novel radiosensitizers for NPC therapy. EBV infection in NPC is classified as type II latent infection in which only EBV nuclear antigen-1(EBNA-1), latent membrane protein-1(LMP1), LMP2, and EBV early RNA (EBER) expressions can be detected. Among these proteins, LMP1 is thought to play a key role in the pathogenesis of NPC. As a 60kD integral membrane protein, LMP1 functions as a constitutively active tumor necrosis factor receptor (TNFR), and contributes to multiple aspects of NPC through activating a number of signaling pathways including nuclear factor NF-κB, activator protein-1(AP-1), and Janus kinase/signal transducer and activator of transcription(JAK/STAT). Activation of NF-kB or AP-1 by LMP1 has been linked to the upregulation of some cellular proteins and inhibition of apoptosis. Depending on the cell types, expression of LMP1 has been shown to play different roles in response to biological and physiological stimulus. It acts as a primary oncoprotein for human cell immortalization and is also shown as the only EBV-coded product that can transform rodent fibroblast cell line, human epithelial cells and keratinocytes. Given the critical role of viral oncoproteins in transformation and apoptosis, suppression of some viral oncoproteins would provide a sensible strategy to genetically treat NPC. Indeed, antisense oligonucleotides against LMP1 or EBNA1 have been shown to inhibit viral oncoprotein expression, induce apoptosis, and sensitize the EBV-positive cells to cytotoxic agents. Recently, some experimental studies indicated that the RNA interference against LMP1 exhibited an anti-proliferative and anti-metastasis effect in LMP1 expressing NPCs. These results suggested that EBV-encoded LMP1 may present a potential molecular target for treatment of EBV-associated carcinomas. DNAzymes are synthetic, single-stranded DNA oligonucleotides that can be engineered to bind to their complementary sequence in a target messenger RNA (mRNA) through Watson-Crick base pairing and cleave the mRNA at predetermined phosphodiester linkages. A general model for the DNAzyme has been proposed, and is known as the ''10-23'' model. A ''10-23'' DNAzyme has a catalytic domain of 15 deoxyribonucleotides, flanked by two substrate-recognition domains of seven to nine deoxyribonucleotides at each arm. In vitro analyses showed that this type of DNAzyme could effectively cleave its substrate RNA at purine: pyrimidine junctions under physiological conditions. These agents have been used in a number of in vitro and in vivo applications to inhibit the expression of their target genes and the dependent genes. Their capacity to block development of a diverse range of pathologies in animal models suggests that DNAzymes can be used as therapeutic agents. To develop EBV-LMP1 targeted DNAzymes for NPC treatment, we showed that the phosphorothioate-modified ''10-23'' DNAzymes specifically targeted at the LMP1 mRNA could significantly down-regulate the expression of LMP1 in a nasopharyngeal carcinoma cell (NPC) and affected the down-stream pathways activated by LMP1, including the NF-κB pathway. It was also demonstrated that suppression of the LMP1 expression by the LMP1-targeted DNAzyme DZ1 could enhance radiosensitivity both in vivo and vitro. Radio-resistance has been one of the impediments in clinical settings for effective cancer therapy, which is thought to be associated with multiple signaling pathways in different cancer types. ATM (ataxia telangiectasia mutated) is a nuclear 350-kDa protein kinase with a carboxylterminal phosphatidylinositol 3-kinase-like kinase domain[1]. It functions as a member of a coordinated system that detects DNA breaks; arrests the cells temporarily at G1, S, or G2 checkpoints; and activates DNA repair. Cells lacking functional ATM protein show increased sensitivity to ionizing radiation (IR) and other genotoxic events. NF-κB (nuclear factor kappa B) can activate a great number of genes involved in stress responses, inflammation, and programmed cell death (apoptosis). P50 homodimers or p50/p65 or p50/c-Rel heterodimers bind to the NF-κB DNA binding sites in the promoter regions of many stress-responsive genes, suggesting a complex gene and physiological regulation network controlled by NF-κB in stress response. The elevated basal NF-κB activity in certain cancers has been linked to tumor resistance to chemotherapy and radiation. Inhibition of NF-κB blocked the adaptive radioresistance. Our studies for the molecular mechanism of the LMP1-DNAzyme mediated radiosensitization revealed that LMP1 activated the ATM expression through the NF-κB pathway and inhibition of LMP1 expression by the DNAzyme attenuated the binding of NF-κB transcription factor to the ATM promoter. Further evidence showed that the radiosensitivity was recovered when the ATM expression was knocked down by siRNA in NPCs. Together, all our data support our hypothesis and provide solid experimental basis for the use of LMP1-targeted DNAzymes as potential radiosensitizers for treatment of the EBV-associated carcinomas. Toxicological studies in mice showed that no morbidity or mortality was observed in any of the dosing groups during the course of the study (50mg, 100mg, and 200mg/kg). All hematological values and biochemistry results from tests of hepatic and renal function were normal. No microscopic lesion that could be attributed to the modified DNAzyme oligonucleotide treatment was found in liver, spleen and kidney in any groups. After i.v. administration of 100 mg/kg DNAzyme oligonucleotide in mice, the peak plasma concentration of 24.13±2.6μg/ml was achieved. The decrease in plasma concentration of DNAzyme followed a bi-exponential pattern with initial distribution half-life (t1/2α) of 0.18±0.03 h and a terminal half-life (t1/2β) of 2.55±1.0 h, and area under the plasma concentration-time curve (AUC) was 54.17±9.1μg.h/ml. STUDY DESIGN This study will be a randomized, double-blinded and placebo controlled Phase I/II clinical trial. Forty (40) patients will be randomized to one of two groups of equal size: placebo group receiving saline by intra-tumor injection and standard radiotherapy; or DZ1 group receiving LMP1 DNAzyme (DZ1) and standard radiotherapy. The placebo group will provide the basis for assessment of safety and efficacy of DZ1. Patients receive placebo or DZ1 injection two (2) hours prior to radical radiation therapy on Monday and Thursday over seven weeks. The radical radiotherapy is given to patients 5 times per week with 2 Gy of each treatment. The entire procedure lasts seven weeks. All patients will complete the study at 104 weeks post-first injection. The patients will undergo assessment and testing every week in the first seven weeks, then every three months from the weeks 8 to week 104. The study will include evaluations of safety and tolerability:
4 schema:endDate 2011-09-01T00:00:00Z
5 schema:keywords ATM
6 Area Under Curve
7 Base Pairing
8 Catalytic DNA
9 Catalytic Domain
10 Chinese population
11 DNA break
12 DNA repair
13 Drug Therapy
14 EBNA-1
15 Epstein Barr
16 Epstein-Barr virus genome
17 Epstein-Barr virus infection
18 Evaluation Study as Topic
19 G1
20 G2 checkpoint
21 Genetic Promoter Region
22 Gy
23 Hong Kong
24 Human Herpesvirus 4
25 JAK/STAT
26 LMP1
27 LMP2
28 Messenger RNA
29 NF
30 NF-κB
31 Organization and Administration
32 Phase I/II
33 RNA interference
34 Radiation Tolerance
35 Singapore
36 Taiwan
37 Transcription Factor AP-1
38 Tumor Necrosis Factor Receptor
39 Up-Regulation
40 activator
41 agent
42 animal model
43 antisense oligonucleotides
44 apoptosis
45 arm
46 assessment
47 association
48 ataxia telangiectasia
49 binding
50 binding site
51 biochemistry
52 capacity
53 cell
54 cell immortalization
55 cell type
56 cellular protein
57 certain cancer
58 clinical issue
59 clinical setting
60 clinical trial
61 close association
62 complementary sequence
63 complex
64 coordinated system
65 critical role
66 cytotoxic agent
67 decrease
68 deoxyribonucleotides
69 development
70 different cancer type
71 different role
72 diverse range
73 dosing
74 down-stream
75 effective cancer therapy
76 efficacy
77 epithelial malignancy
78 equal size
79 evidence
80 experimental basis
81 experimental study
82 expression
83 fibroblast cell line
84 first-line treatment
85 gene
86 general model
87 geographic distribution
88 great number
89 half-life
90 heterodimer
91 high incidence rate
92 homodimer
93 human epithelial cell
94 human virus
95 i.v
96 impediment
97 incidence
98 incidence rate
99 increased sensitivity
100 infection
101 inflammation
102 inhibition
103 initial distribution
104 injection
105 introduction
106 ionizing radiation
107 keratinocytes
108 key role
109 kidney
110 latent infection
111 latent membrane protein
112 latent membrane protein 1
113 lesion
114 liver
115 malignancy
116 membrane protein
117 membrane protein function
118 molecular mechanism
119 morbidity
120 mortality
121 mouse
122 multiple aspect
123 multiple signaling pathway
124 nasopharyngeal carcinoma
125 nuclear antigen
126 nuclear factor
127 nuclear factor kappa
128 oligonucleotides
129 oncoprotein
130 pathogenesis
131 pathology
132 patient
133 pattern
134 phosphatidylinositol kinase
135 phosphodiester
136 physiological condition
137 physiological regulation
138 physiological stimulus
139 placebo
140 placebo group
141 plasma concentration
142 positive cell
143 potential molecular target
144 programmed cell death
145 promoter
146 protein
147 protein kinase
148 purine
149 pyrimidine
150 radiation
151 radiation therapy
152 radioresistance
153 radiosensitization
154 radiosensitizers
155 radiotherapy
156 renal function
157 resistance
158 responsive gene
159 safety
160 saline
161 serious health problem
162 signaling pathway
163 similar rate
164 single-stranded DNA
165 spleen
166 standard radiotherapy
167 stress response
168 study design
169 substrate RNA
170 substrate recognition
171 suppression
172 target gene
173 therapeutic agent
174 tolerability
175 toxicological study
176 transcription
177 transcription factor
178 transducer
179 transformation
180 tumor resistance
181 unique feature
182 viral oncoproteins
183 vitro
184 vitro analysis
185 vivo
186 vivo application
187 white population
188 schema:name Phase I/II Study of EBV-LMP1 Targeted DNAzyme in Nasopharyngeal Carcinoma
189 schema:sameAs https://app.dimensions.ai/details/clinical_trial/NCT01449942
190 schema:sdDatePublished 2019-03-07T15:24
191 schema:sdLicense https://scigraph.springernature.com/explorer/license/
192 schema:sdPublisher N650802adef2d4c058ee770d2c0dffca9
193 schema:sponsor https://www.grid.ac/institutes/grid.452223.0
194 schema:startDate 2009-05-01T00:00:00Z
195 schema:subjectOf sg:pub.10.1038/8658
196 sg:pub.10.1038/nrc3138
197 sg:pub.10.1038/sj.cgt.7700833
198 sg:pub.10.1186/1471-2407-14-835
199 https://app.dimensions.ai/details/publication/pub.1074695863
200 https://app.dimensions.ai/details/publication/pub.1077439827
201 https://doi.org/10.1016/j.canlet.2008.02.019
202 https://doi.org/10.1089/108729002761381276
203 https://doi.org/10.3390/molecules15096127
204 schema:url https://clinicaltrials.gov/show/NCT01449942
205 sgo:license sg:explorer/license/
206 sgo:sdDataset clinical_trials
207 rdf:type schema:MedicalStudy
208 N650802adef2d4c058ee770d2c0dffca9 schema:name Springer Nature - SN SciGraph project
209 rdf:type schema:Organization
210 anzsrc-for:3053 schema:inDefinedTermSet anzsrc-for:
211 rdf:type schema:DefinedTerm
212 anzsrc-for:3142 schema:inDefinedTermSet anzsrc-for:
213 rdf:type schema:DefinedTerm
214 sg:pub.10.1038/8658 schema:sameAs https://app.dimensions.ai/details/publication/pub.1041797087
215 https://doi.org/10.1038/8658
216 rdf:type schema:CreativeWork
217 sg:pub.10.1038/nrc3138 schema:sameAs https://app.dimensions.ai/details/publication/pub.1019467785
218 https://doi.org/10.1038/nrc3138
219 rdf:type schema:CreativeWork
220 sg:pub.10.1038/sj.cgt.7700833 schema:sameAs https://app.dimensions.ai/details/publication/pub.1008611413
221 https://doi.org/10.1038/sj.cgt.7700833
222 rdf:type schema:CreativeWork
223 sg:pub.10.1186/1471-2407-14-835 schema:sameAs https://app.dimensions.ai/details/publication/pub.1024606096
224 https://doi.org/10.1186/1471-2407-14-835
225 rdf:type schema:CreativeWork
226 https://app.dimensions.ai/details/publication/pub.1074695863 schema:CreativeWork
227 https://app.dimensions.ai/details/publication/pub.1077439827 schema:CreativeWork
228 https://doi.org/10.1016/j.canlet.2008.02.019 schema:sameAs https://app.dimensions.ai/details/publication/pub.1029804240
229 rdf:type schema:CreativeWork
230 https://doi.org/10.1089/108729002761381276 schema:sameAs https://app.dimensions.ai/details/publication/pub.1059208060
231 rdf:type schema:CreativeWork
232 https://doi.org/10.3390/molecules15096127 schema:sameAs https://app.dimensions.ai/details/publication/pub.1021869764
233 rdf:type schema:CreativeWork
234 https://www.grid.ac/institutes/grid.452223.0 schema:Organization
 




Preview window. Press ESC to close (or click here)


...