This Article Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Walther, W. Articles by Schlag, P. M. Search for Related Content PubMed PubMed Citation Articles by Walther, W. Articles by Schlag, P. M.

Research Articles: Therapeutics, Targets, and Development

Heat-inducible in vivo gene therapy of colon carcinoma by human mdr1 promoter–regulated tumor necrosis factor- expression

¹ Max-Delbrück-Center for Molecular Medicine and ² Robert-Rössle-Clinic, Charité, Berlin, Germany

Requests for reprints: Wolfgang Walther, Max-Delbrück-Center for Molecular Medicine, Robert-Rössle-Strasse 10, 13092 Berlin, Germany. Phone: 49-30-9406-3432; Fax: 49-30-9406-2780. E-mail: wowalt{at}mdc-berlin.de

Abstract

The promoter of the human multidrug resistance gene (mdr1) harbors defined heat-responsive elements, which could be exploited for construction of heat-inducible expression vectors. To analyze the hyperthermia inducibility of the mdr1 promoter in vitro and in vivo, we used the pcDNA3-mdrp-hTNF vector construct for heat-induced tumor necrosis factor (TNF-) expression in transfected HCT116 human colon carcinoma cells at mRNA level by quantitative real-time reverse transcription-PCR and at protein level by TNF- ELISA. For the in vitro studies, the pcDNA3-mdrp-hTNF–transfected tumor cells were treated with hyperthermia at 43°C for 2 h. In the animal studies, stably transfected or in vivo jet-injected tumor-bearing Ncr:nu/nu mice were treated for 60 min at 42°C to induce TNF- expression. Both the in vitro and in vivo experiments show that hyperthermia activates the mdr1 promoter in a temperature- and time-dependent manner, leading to an up to 4-fold increase in mdr1 promoter–driven TNF- expression at mRNA and an up to 3-fold increase at protein level. The in vivo heat-induced TNF- expression combined with Adriamycin (8 mg/kg) treatment leads to the inhibition of tumor growth in the animals. These experiments support the idea that heat-induced mdr1 promoter–driven expression of therapeutic genes is efficient and feasible for combined cancer gene therapy approaches. [Mol Cancer Ther 2007;6(1):236–43]

Grant support: Deutsche Forschungsgemeinschaft, Germany, H.W. & J. Hector Foundation, Mannheim, Germany, and EMS Medical Systems SA, Nyon, Switzerland.

The costs of publication of this article were defrayed in part by the payment of page charges. This article must therefore be hereby marked advertisement in accordance with 18 U.S.C. Section 1734 solely to indicate this fact.

Received 2/ 6/06; revised 10/23/06; accepted 11/22/06.