A complex adenovirus vector that delivers FASL-GFP with combined prostate-specific and tetracycline-regulated expression.
Cell-type-restricted transgene expression delivered by adenovirus vectors is highly desirable for gene therapy of cancer, as it can limit cytotoxic gene expression to tumor cells. However, many tumor- and tissue-specific promoters are weaker than the constitutively active promoters and are thus less effective. To combine cell-type specificity with high-level regulated transgene expression, we have developed a complex adenoviral vector. We have placed the tetracycline transactivator gene under the control of a prostate-specific ARR2PB promoter, and a mouse Tnfsf6 (encoding FASL)-GFP fusion gene under the control of the tetracycline responsive promoter. We have incorporated both expression cassettes into a single construct. We show that FASL-GFP expression from this vector is essentially restricted to prostate cancer cells, in which it can be regulated by doxycycline. Higher levels of prostate-specific FASL-GFP expression were generated by this approach than by driving the FASL-GFP expression directly with ARR2PB. More FASL-GFP expression correlated with greater induction of apoptosis in prostate cancer LNCaP cells. Mouse studies confirmed that systemic delivery of both the prostate-specific and the prostate-specific/tet-regulated vectors was well tolerated at doses that were lethal for FASL-GFP vector with CMV promoter. This strategy should be able to improve the safety and efficacy of cancer gene therapy using other cytotoxic genes as well.
Rubinchik
S
S
Department of Microbiology and Immunology, Medical University of South Carolina, Charlestown, SC 29403, USA
Wang
D
D
Yu
H
H
Fan
F
F
Luo
M
M
Norris
J S
JS
Dong
J Y
JY
D000256:Adenoviridae / Q000235:genetics*; D000818:Animals; D017209:Apoptosis / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D004318:Doxycycline / Q000494:pharmacology; D053222:Fas Ligand Protein; D005786:Gene Expression Regulation / Q000187:drug effects*; D005822:Genetic Vectors / Q000009:adverse effects / Q000235:genetics*; D049452:Green Fluorescent Proteins; D006801:Humans; D008099:Liver / Q000187:drug effects / Q000378:metabolism / Q000473:pathology; D008164:Luminescent Proteins / Q000009:adverse effects / Q000032:analysis / Q000235:genetics*; D008297:Male; D008562:Membrane Glycoproteins / Q000009:adverse effects / Q000235:genetics*; D051379:Mice; D009928:Organ Specificity; D011401:Promoter Regions, Genetic / Q000235:genetics; D011467:Prostate / Q000187:drug effects / Q000378:metabolism* / Q000473:pathology; D011471:Prostatic Neoplasms / Q000235:genetics / Q000378:metabolism / Q000628:therapy*; D013752:Tetracycline / Q000494:pharmacology*; D013997:Time Factors; D014407:Tumor Cells, Cultured
C505661:FASLG protein, human; D053222:Fas Ligand Protein; C505658:Fasl protein, mouse; D008164:Luminescent Proteins; D008562:Membrane Glycoproteins; D049452:Green Fluorescent Proteins; D013752:Tetracycline; D004318:Doxycycline