title: Development of chimeric gene regulators for cancer-specific gene therapy with both transcriptional and translational targeting.
abstract: Cancer gene therapy has been of great challenge in achieving maximal high levels of specificity and more rational efficiency in target cancer cell. We herein developed a novel approach for cancer-specific gene therapy using both transcriptional and translational targeting regulation. We integrated the tumor-specific gene promoter of hTERT, the 5'UTR of bFGF-2, the enhancer of woodchuck hepatitis virus post-transcriptional regulatory element (WRE), and/or the 3'UTR of the human EGFR into two major chimeric gene regulators. We found that chimeric gene regulator I (hTERT_5'UTR...WRE_BGHpolyA) enhanced the specificity of expression in hepatocellular carcinoma (HCC) cells up to 300% in total due to increases at both the transcriptional and translational levels but only 120-200% enhancement at the transcriptional level and 120-180% enhancement at the translational level. In addition, chimeric gene regulator II (hTERT_5'UTR...WRE_3'UTR_BGHpolyA) improved the specificity to 550% and also highly strengthened the stability of the mRNA. In vitro cytotoxicity assays demonstrated that HCC cell growth was inhibited by HSV-1 TK expression under the control of both chimeric regulators, with a relative cell viability of approximately 80% for 2 days and approximately 85% for 4 days after transfection, respectively. These observations represent a new approach for highly tumor-specific gene expression and also provide insights into application to cancer gene therapy.
authors.affiliation: State Key Laboratory of Genetic Engineering and Institute of Genetics, School of Life Sciences, Fudan University, Shanghai, People's Republic of China.
authors.forename: Yu Xiang
authors.initials: YX
authors.lastname: Fang
authors.forename: Xiao Bo
authors.initials: XB
authors.lastname: Zhang
authors.forename: Wei
authors.initials: W
authors.lastname: Wei
authors.forename: Yi Wen
authors.initials: YW
authors.lastname: Liu
authors.forename: Jin Zhong
authors.initials: JZ
authors.lastname: Chen
authors.forename: Jing Lun
authors.initials: JL
authors.lastname: Xue
authors.forename: Ling
authors.initials: L
authors.lastname: Tian
mesh_terms: D006528:Carcinoma, Hepatocellular / Q000235:genetics* / Q000628:therapy*; D045744:Cell Line, Tumor; D015972:Gene Expression Regulation, Neoplastic; D018390:Gene Targeting / Q000379:methods*; D015316:Genetic Therapy / Q000379:methods*; D006801:Humans; D014176:Protein Biosynthesis / Q000235:genetics*; D014157:Transcription Factors / Q000235:genetics*
chemical_list: D014157:Transcription Factors