Abstract |
The cytomegalovirus-immediate early (CMV-IE) promoter is widely used as a strong and constitutively active promoter. Although the CMV-IE promoter does not harbor heat-responsive sequences, we determined its heat inducibility. We analyzed in vitro and in vivo heat responsiveness and possible mechanisms of heat induction of the CMV-IE promoter. We used transfected SW480 human colon carcinoma cells (SW480/CMVCD), expressing CMV-IE promoter-driven bacterial cytosine deaminase (CD) gene. These cells were heated at 42 degrees C. The SW480/CMVCD cells were also used for in vivo studies, in which tumor-bearing animals were treated with hyperthermia at 41.5 degrees C. As controls, SW480 (SW480/HSPCD) cells were used, in which CD expression is driven by the HSP70-promoter. In vitro, we observed a biphasic, up to 25-fold heat induction of CMV-IE-driven CD expression after hyperthermia in SW480/CMVCD cells. In vivo, we found a 2.5-fold induction of CD expression after hyperthermia in SW480/CMVCD tumor-bearing animals. The analysis of the CMV-IE promoter sequence revealed several transcription factor-binding sites, which mediate stress responsiveness. YB-1 and C/EBP-beta might mediate heat responsiveness of the CMV-IE promoter. These data point to limitations in heat-induction gene therapy studies, in which the CMV-IE promoter is used as control system. In addition, the CMV-IE promoter itself could well be used for construction of heat-inducible vectors.
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Authors | Dennis Kobelt, Jutta Aumann, Iduna Fichtner, Ulrike Stein, Peter M Schlag, Wolfgang Walther |
Journal | Molecular biotechnology
(Mol Biotechnol)
Vol. 46
Issue 2
Pg. 197-205
(Oct 2010)
ISSN: 1559-0305 [Electronic] United States |
PMID | 20512535
(Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
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Chemical References |
- Transcription Factors
- Cytosine Deaminase
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Topics |
- Animals
- Cell Line, Tumor
- Colonic Neoplasms
(genetics, therapy)
- Cytosine Deaminase
(genetics, metabolism)
- Disease Models, Animal
- Enzyme Induction
(genetics)
- Gene Expression Regulation, Neoplastic
(genetics)
- Genetic Therapy
(methods)
- Humans
- Hyperthermia, Induced
- Male
- Mice
- Mice, Inbred NOD
- Promoter Regions, Genetic
(genetics)
- Transcription Factors
(metabolism)
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