title: Adenovirus-mediated suicide gene therapy under the control of Cox-2 promoter for colorectal cancer.
abstract: Colorectal cancer is a most frequent type of gastrointestinal tract cancers. The prognosis of patients with colorectal cancer remains poor despite intensive interventions. Tumor specific promoter-directed gene therapy and adenoviral technology can be promising strategies for such advanced disease. This study was conducted to explore the possible therapeutic approach of Cox-2 promoter-directed suicide gene therapy with herpes simplex virus thymidine kinase (HSV-tk) in combination with adenoviral technology for advanced colorectal cancer. Firstly, the activity of Cox-2 promoter was assessed by dual luciferase and enhanced green fluorescent protein reporter gene assays in colorectal cancer cell lines and normal human intestinal epithelial cell line. Then, the expression of coxsackievirus and adenovirus receptor (CAR) was detected in colorectal cancer cell lines. The Cox-2 promoter-directed HSV-tk/ganciclovir (GCV) system mediated by adenovirus (Ad-Cp-TK) was developed (Ad-CMVp-TK, Ad-null and no Ad as controls). In vitro cytoxicity, colony formation and apoptosis assays were performed using Ad-Cp-TK. An animal study was carried out in which BALB/C nude mice bearing tumors were treated with Ad-Cp-TK and GCV treatments. Results showed that Cox-2 promoter possessed high transcriptional activity in a tumor-specific manner. All colorectal cancer cells were detected CAR-positive. In vitro cytotoxic and colony formation assays showed that colorectal cancer cells infected with Ad-Cp-TK became more sensitive to GCV but the sensitivity of normal cells infected with Ad-Cp-TK to GCV were not altered. Moreover, the Ad-Cp-TK system combined with GCV treatment could significantly induce apoptosis of colorectal cancer cells but not normal intestinal epithelial cells. Furthermore, this system also significantly inhibited the growth of subcutaneous tumors and prolonged survival of mice. Thus, adenovirus primary receptor was positive in colorectal cancer cells and adenovirus-mediated suicide gene therapy under the control of Cox-2 promoter could provide a promising treatment modality for advanced colorectal cancer with tumor specificity.
authors: Department of Oncology, The Second Affiliated Hospital, Nanjing Medical University, Nanjing, China.
authors: Zhao-Xia
authors: ZX
authors: Wang
authors: Hai-Bo
authors: HB
authors: Bian
authors: Jing-Song
authors: JS
authors: Yang
authors: Wei
authors: W
authors: De
authors: Xiao-Hui
authors: XH
authors: Ji
mesh_terms: D000230:Adenocarcinoma / Q000201:enzymology / Q000473:pathology / Q000628:therapy*; D000256:Adenoviridae / Q000235:genetics*; D000818:Animals; D001711:Biotransformation; D015179:Colorectal Neoplasms / Q000201:enzymology / Q000473:pathology / Q000628:therapy*; D062727:Coxsackie and Adenovirus Receptor-Like Membrane Protein; D051546:Cyclooxygenase 2 / Q000096:biosynthesis / Q000235:genetics*; D015774:Ganciclovir / Q000493:pharmacokinetics / Q000627:therapeutic use*; D017930:Genes, Reporter; D005813:Genes, Synthetic; D041722:Genes, Transgenic, Suicide; D015316:Genetic Therapy / Q000379:methods*; D005822:Genetic Vectors / Q000235:genetics / Q000627:therapeutic use*; D006801:Humans; D007413:Intestinal Mucosa / Q000201:enzymology; D051379:Mice; D008807:Mice, Inbred BALB C; D008819:Mice, Nude; D009363:Neoplasm Proteins / Q000502:physiology; D011355:Prodrugs / Q000493:pharmacokinetics / Q000627:therapeutic use*; D011401:Promoter Regions, Genetic / Q000235:genetics*; D011991:Receptors, Virus / Q000502:physiology; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D018139:Simplexvirus / Q000201:enzymology / Q000235:genetics; D013937:Thymidine Kinase / Q000378:metabolism; D014158:Transcription, Genetic; D014410:Tumor Stem Cell Assay; D023041:Xenograft Model Antitumor Assays
chemical_list: C568771:CLMP protein, human; C568772:CLMP protein, mouse; D062727:Coxsackie and Adenovirus Receptor-Like Membrane Protein; D009363:Neoplasm Proteins; D011355:Prodrugs; D011991:Receptors, Virus; D011993:Recombinant Fusion Proteins; D051546:Cyclooxygenase 2; C496540:PTGS2 protein, human; D013937:Thymidine Kinase; D015774:Ganciclovir