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Photochemical Internalization of Transgenes Controlled by the Heat‐shock Protein 70 Promoter
Author(s) -
Prasmickaite Lina,
Hellum Marit,
Kaalhus Olav,
Høgset Anders,
Wagner Ernst,
Berg Kristian
Publication year - 2006
Publication title -
photochemistry and photobiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.818
H-Index - 131
eISSN - 1751-1097
pISSN - 0031-8655
DOI - 10.1562/2005-11-07-ra-731
Subject(s) - internalization , heat shock protein , transgene , chemistry , hsp70 , microbiology and biotechnology , photochemistry , biophysics , biology , gene , biochemistry , receptor
Photochemical internalization (PCI) is a targeting technique that facilitates endosomal escape of macromolecules, such as transgenes, in response to photochemical treatment with endosome/lysosome‐localized photosensitizers, such as disul‐fonated meso‐tetraphenylporphine (TPPS 2a ). In gene therapy this leads to enhanced transgene expression. Moreover, photochemical treatment generally activates transcription of stress‐response genes, such as heat‐shock proteins (HSPs), via stimulation of corresponding promoters. Therefore, we used HSP70 (HSPp; a promoter from the HSP family gene) and investigated whether the PCI stimulus could also activate HSPp and thereby stimulate transcription (expression) of the HSPp‐controlled transgene internalized via PCI. Using human colorectal carcinoma and hepatoma cell lines in vitro , we showed that TPPS 2a ‐based photochemical treatment enhances expression of cellular HSP70, which correlated with a photo‐chemically enhanced expression (approximately 2‐fold, at PCI‐optimal doses) of the HSPp‐controlled transgene integrated in the genome. Furthermore, PCI enhanced expression of the HSPp‐controlled episomal transgene delivered as a plas‐mid. However, in plasmid‐based transfection, PCI‐mediated enhancement with HSPp did not exceed the enhancement achieved with the constitutive active CMV promoter. In conclusion, we demonstrated that the PCI‐relevant treatment initiates HSP70 response and that the HSP70 promoter can be used in combination with PCI, leading to PCI‐enhanced expression of the HSPp‐controlled transgene.