[Gene therapy targeting for carcinoma regulated by E2F-1 promoter].
OBJECTIVE
To study the selective effect to tumor cells mediated by a recombinant adenoviral vector carrying E2F-1 promoter.


METHODS
The AdEasy-1 adenoviral vector system was used in this experiment. Several recombinant adenovirus with tumor-targeting E2F-1 promoter were constructed and then the E2F-1 promoter gene was checked by PCR and sequencing. The two adenovirus expressing GFP gene which is regulated by E2F-1 promoter or CMV promoter were used to respectively transfect tumor cells and non-proliferating normal cells, then observed and analyzed the different results caused by different promoters. Vpr gene was cloned into the targeting recombinant adenovirus. The new adenovirus named rvAdE2F-1/vpr was used to transfect tumor cells SMMC-7721, LS174T and non-proliferating normal cells H292, L-02. The surviving rate of each group was registered; the level of E2F-1 protein expressed in normal and tumor cell lines were checked by Western Blot.


RESULTS
E2F-1 promoter can regulate the downstream gene GFP selectively expressed in LS174T and its activity in LS174T was similar with CMV promoter's; Vpr gene regulated by E2F-1 promoter can suppress the proliferation of tumor cells and no toxicity to normal cells; In all of the tumor cells, a much higher level of E2F-1 was expressed compared with normal cell lines. E2F-1 promoter's activity correlated well with E2F-1 protein levels.


CONCLUSIONS
E2F-1 promoter can control a selective cell killing to cancer cells, with no effect to normal cells. The system of E2F-1 promoter is a useful method for tumor-targeting gene therapy.
Zhang
Xue-wen
XW
Department of General Surgery, China-Japan Union Hospital, Jilin University, Changchun 130033, China.
Meng
Zi-hui
ZH
Zhao
Ji-sheng
JS
Zhang
Dan
D
Xie
Ying-jun
YJ
Gao
Shuo-hui
SH
Wang
Chun-yan
CY
D000256:Adenoviridae / Q000235:genetics*; D015153:Blotting, Western; D002460:Cell Line; D045744:Cell Line, Tumor; D049109:Cell Proliferation; D050687:E2F1 Transcription Factor / Q000235:genetics* / Q000378:metabolism; D016336:Gene Products, vpr / Q000235:genetics* / Q000502:physiology; D015316:Genetic Therapy / Q000379:methods; D005822:Genetic Vectors; D049452:Green Fluorescent Proteins / Q000235:genetics / Q000378:metabolism; D006801:Humans; D009369:Neoplasms / Q000235:genetics / Q000473:pathology / Q000628:therapy; D011401:Promoter Regions, Genetic / Q000235:genetics*; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D014162:Transfection
D050687:E2F1 Transcription Factor; C493753:E2F1 protein, human; D016336:Gene Products, vpr; D011993:Recombinant Fusion Proteins; D049452:Green Fluorescent Proteins