Gene therapy for colorectal cancer by an oncolytic adenovirus that targets loss of the insulin-like growth factor 2 imprinting system

• Published in: Molecular cancer 2012-11, Vol.11 (1), p.86-86, Article 86
• Main Authors: Nie, Zhen-Lin, Pan, Yu-Qin, He, Bang-Shun, Gu, Ling, Chen, Li-Ping, Li, Rui, Xu, Ye-Qiong, Gao, Tian-Yi, Song, Guo-Qi, Hoffman, Andrew R, Wang, Shu-Kui, Hu, Ji-Fan
• Format: Article
• Language: English
• Subjects: Adenovirus; Adenovirus E1A Proteins - genetics; Adenoviruses; Animals; Antineoplastic Agents; Apoptosis; Apoptosis - genetics; Cancer; Cell Line, Tumor; Cell Survival - genetics; Cloning, Molecular; Colorectal cancer; Colorectal Neoplasms - genetics; Colorectal Neoplasms - therapy; Colorectal Neoplasms - virology; Diabetes therapy; Epigenetic inheritance; Epigenetics; Experiments; Female; Fluorescence; Gene therapy; Genes; Genetic aspects; Genetic engineering; Genetic Therapy - methods; Genomic imprinting; Genomic Imprinting - genetics; Green Fluorescent Proteins - genetics; Green Fluorescent Proteins - metabolism; Health aspects; HT29 Cells; Human adenovirus; Humans; IGF2; Insulin-Like Growth Factor II - genetics; Insulin-like growth factors; Kaplan-Meier Estimate; Life sciences; Medical research; Mice; Mice, Nude; Oncolytic adenovirus; Oncolytic Virotherapy - methods; Proteins; Statistical analysis; Targeted therapy; Transfection; Tumors; Xenograft Model Antitumor Assays
• ISSN: 1476-4598; 1476-4598
• DOI: 10.1186/1476-4598-11-86

Colorectal cancer is one of the most common malignant tumors worldwide. Loss of imprinting (LOI) of the insulin-like growth factor 2 (IGF2) gene is an epigenetic abnormality observed in human colorectal neoplasms. Our aim was to investigate the feasibility of using the IGF2 imprinting system for targeted gene therapy of colorectal cancer. We constructed a novel oncolytic adenovirus, Ad315-E1A, and a replication-deficient recombinant adenovirus, Ad315-EGFP, driven by the IGF2 imprinting system by inserting the H19 promoter, CCCTC binding factor, enhancer, human adenovirus early region 1A (E1A) and enhanced green fluorescent protein (EGFP) reporter gene into a pDC-315 shuttle plasmid. Cell lines with IGF2 LOI (HCT-8 and HT-29), which were infected with Ad315-EGFP, produced EGFP. However, no EGFP was produced in cell lines with maintenance of imprinting (HCT116 and GES-1). We found that Ad315-E1A significantly decreased cell viability and induced apoptosis only in LOI cell lines in vitro. In addition, mice bearing HCT-8-xenografted tumors, which received intratumoral administration of the oncolytic adenovirus, showed significantly reduced tumor growth and enhanced survival. Our recombinant oncolytic virus targeting the IGF2 LOI system inhibits LOI cell growth in vitro and in vivo, and provides a novel approach for targeted gene therapy.