ABSTRACT
Several light-regulated genetic circuits have been applied to spatiotemporally control transgene expression in mammalian cells. However, simultaneous regulation of multiple genes using one genetic device by light has not yet been reported. In this study, we engineered a bidirectional expression module based on LightOn system. Our data showed that both reporter genes could be regulated at defined and quantitative levels. Simultaneous regulation of four genes was further achieved in cultured cells and mice. Additionally, we successfully utilized the bidirectional expression module to monitor the expression of a suicide gene, showing potential for photodynamic gene therapy. Collectively, we provide a robust and useful tool to simultaneously control multiple genes expression by light, which will be widely used in biomedical research and biotechnology.
Subject(s)
Gene Expression Regulation/radiation effects , Genetic Techniques , Light , Animals , Biotechnology , COS Cells , Cell Line , Chlorocebus aethiops , Genes, Reporter/radiation effects , Genes, Transgenic, Suicide/radiation effects , Genetic Therapy , HEK293 Cells , Humans , Luminescent Proteins/genetics , Mice , Photochemotherapy , Transgenes/radiation effectsABSTRACT
Herpes simplex virus thymidine kinase (HSV-TK) and Escherichia coli cytosine deaminase (CD) can convert innocuous prodrugs into cytotoxic metabolites and are being investigated for use in gene therapy for cancer. Human adenoid cystic carcinoma (ACC-2) cells transduced with a CD/HSV-TK fusion gene (ACC-2/CD-TK cells) were found to be more sensitive to radiation than ACC-2 cells when exposed to 5-fluorocytosine (5-FC; 40 microg/ml) plus ganciclovir (0.1 microg/ml) for 48 h before irradiation. Analysis of radiation survival curves for cells exposed to 5-FC plus ganciclovir before irradiation showed that ACC-2 cells had a higher capacity for sublethal damage repair (D(q) value) and greater cellular radiosensitivity (D(0) value) than ACC-2/CD-TK cells. Colony formation rate after 2 Gy of irradiation was significantly greater for ACC-2 than for ACC-2/CD-TK cells when cells were treated with 5-FC plus ganciclovir before irradiation. This study, therefore, indicates that addition of radiation might substantially improve the therapeutic potential of CD-TK fusion gene therapy of human adenoid cystic carcinomas.
