Identification of tissue- and cancer-selective promoters for the introduction of genes into human ovarian cancer cells.
OBJECTIVE
One potential limitation of gene therapy for epithelial tumors is the lack of tissue or tumor specificity of treatment. Tumor-selective expression of gene therapies may avoid deleterious side effects and improve the efficacy of the treatment. The aim of this study was to evaluate the tissue and tumor specificity of four different potential gene therapy promoters, to determine their usefulness in tissue-specific gene therapy of epithelial ovarian carcinomas.


METHODS
Three potential epithelial cell-selective (hESE1, SLP1, OSP1) and one potential tumor-selective (hTERT) promoter were placed upstream of a luciferase construct to determine relative activity in a wide variety of normal and malignant cell lines. Transient transfection and luciferase assays were carried out in 12 epithelial ovarian (3 SV40 T antigen-transfected normal and 9 malignant) and 8 control cell lines.


RESULTS
Luciferase assays revealed that the hTERT promoter presented the highest tumor selectivity. hESE1 and SLP1 promoters showed strong epithelial cell selectivity (hESE1, 16/17; SLP1, 15/17), with the OSP1 (11/17) promoter exhibiting lower epithelial selectivity. Of the potential promoters for gene therapy, hTERT promoter exhibited the strongest transcriptional activity in most of the tumor cell lines. None of the promoters exhibited strict ovarian epithelium selectivity.


CONCLUSIONS
The hTERT promoter may be an optimal promoter for a univector gene therapy approach based on its high tumor selectivity. Utilization of multiple epithelial cell-specific promoters may result in a more tissue-selective gene therapy approach. Using a combination of promoters may prevent potential problems due to expression in nonepithelial stem cells that may constitutively express hTERT.
Tanyi
Janos L
JL
Department of Molecular Therapeutics, University of Texas, Houston, Texas 77030, USA.
Lapushin
Ruth
R
Eder
Astrid
A
Auersperg
Nelly
N
Tabassam
Fazal H
FH
Roth
Jack A
JA
Gu
Jian
J
Fang
Binglian
B
Mills
Gordon B
GB
Wolf
Judith
J
D033942:Adaptor Proteins, Vesicular Transport; D000818:Animals; D019556:COS Cells; D002352:Carrier Proteins / Q000096:biosynthesis / Q000235:genetics; D004268:DNA-Binding Proteins; D004847:Epithelial Cells / Q000166:cytology / Q000378:metabolism; D005260:Female; D005656:Fungal Proteins / Q000096:biosynthesis / Q000235:genetics; D017930:Genes, Reporter / Q000235:genetics; D015316:Genetic Therapy / Q000379:methods*; D006801:Humans; D008156:Luciferases / Q000096:biosynthesis / Q000235:genetics / Q000378:metabolism; D010051:Ovarian Neoplasms / Q000235:genetics* / Q000628:therapy; D011401:Promoter Regions, Genetic / Q000235:genetics*; D012333:RNA, Messenger / Q000096:biosynthesis / Q000235:genetics; D051381:Rats; D019098:Telomerase / Q000235:genetics; D015533:Transcriptional Activation; D014162:Transfection; D014407:Tumor Cells, Cultured
D033942:Adaptor Proteins, Vesicular Transport; D002352:Carrier Proteins; D004268:DNA-Binding Proteins; D005656:Fungal Proteins; C485568:ITSN1 protein, human; D012333:RNA, Messenger; D008156:Luciferases; D019098:Telomerase