Abstract
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.
Original language | English (US) |
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Pages (from-to) | 416-426 |
Number of pages | 11 |
Journal | Molecular Therapy |
Volume | 4 |
Issue number | 5 |
DOIs | |
State | Published - 2001 |
Externally published | Yes |
Keywords
- Combined regulation
- Expression amplification
- Prostate-specific promoter
- Tetracycline expression system
ASJC Scopus subject areas
- Molecular Medicine
- Molecular Biology
- Genetics
- Pharmacology
- Drug Discovery