title: Targeted tumor gene therapy based on loss of IGF2 imprinting.
abstract: Loss of imprinting (LOI) of the insulin-like growth factor 2 gene (IGF2) is one of the most common epigenetic abnormalities seen in human neoplasms. LOI may be associated with the lack of Zinc-finger DNA binding protein CTCF-mediated enhancer insulation, presumably due to the gain of methylation on the maternal allele of the differentially methylated domain (DMD) of the imprinting control region. This results in an interaction between the IGF2 promoters and enhancers; and IGF2 is produced from both alleles. In this study we investigated the feasibility of a novel anti-cancer adenovirus (AdDC312-DT-A) driven by H19 enhancer DMD-H19 promoter complex. Cell lines with IGF2 LOI (HCT-8, HT-29 and H-522) that were infected with AdDC312-EGFP produced the EGFP protein. However, in cells in which imprinting was maintained (MOI) (MCF-7 and GES-1), no EGFP protein was produced. The AdDC312-DT-A significantly decreased cell viability and induced apoptosis only in LOI cells in vitro, and suppressed tumour development in HCT-8 xenografts in nude mice. In conclusion, the toxin gene therapy proves effective in inhibiting LOI cell growth in vitro and in vivo and provides a novel option for targeted gene therapy based on loss of IGF2 imprinting.
authors.affiliation: Central Laboratory of Nanjing First Hospital affiliated to Nanjing Medical University, Nanjing, Jiangsu, China.
authors.forename: Yuqin
authors.initials: Y
authors.lastname: Pan
authors.forename: Bangshun
authors.initials: B
authors.lastname: He
authors.forename: Tao
authors.initials: T
authors.lastname: Li
authors.forename: Chan
authors.initials: C
authors.lastname: Zhu
authors.forename: Lirong
authors.initials: L
authors.lastname: Zhang
authors.forename: Bo
authors.initials: B
authors.lastname: Wang
authors.forename: Yongfei
authors.initials: Y
authors.lastname: Xu
authors.forename: Lili
authors.initials: L
authors.lastname: Qu
authors.forename: Andrew R
authors.initials: AR
authors.lastname: Hoffman
authors.forename: Shukui
authors.initials: S
authors.lastname: Wang
authors.forename: Jifan
authors.initials: J
authors.lastname: Hu
mesh_terms: D000256:Adenoviridae / Q000235:genetics; D000818:Animals; D045744:Cell Line, Tumor; D004167:Diphtheria Toxin / Q000096:biosynthesis / Q000235:genetics; D020869:Gene Expression Profiling; D015316:Genetic Therapy / Q000379:methods*; D018392:Genomic Imprinting; D049452:Green Fluorescent Proteins / Q000096:biosynthesis / Q000235:genetics; D006801:Humans; D007335:Insulin-Like Growth Factor II / Q000235:genetics* / Q000378:metabolism; D008297:Male; D051379:Mice; D008819:Mice, Nude; D058990:Molecular Targeted Therapy / Q000379:methods*; D009369:Neoplasms / Q000235:genetics* / Q000628:therapy*; D010446:Peptide Fragments / Q000096:biosynthesis / Q000235:genetics; D012333:RNA, Messenger / Q000096:biosynthesis / Q000235:genetics; D023041:Xenograft Model Antitumor Assays
chemical_list: D004167:Diphtheria Toxin; C035170:IGF2 protein, human; D010446:Peptide Fragments; D012333:RNA, Messenger; C029795:diphtheria toxin fragment A; C485184:enhanced green fluorescent protein; D049452:Green Fluorescent Proteins; D007335:Insulin-Like Growth Factor II