Cancer‐specific Promoters for Expression‐targeted Gene Therapy: ran, brms1, and mcm5

Abstract BackgroundTo expand the library of promoters that can be used for expression‐targeted gene delivery to cancer cells, the specificity and strength of expression were evaluated for the promoters of three cancer‐related genes: RAS‐related nuclear protein (pran), breast cancer metastasis suppressor 1 (pbrms1), and minichromosome maintenance complex component 5 (pmcm5). MethodsThe expression of reporter genes under the control of these promoters demonstrated selectivity in cancer cell lines of breast, prostate, and ovarian origins, versus a panel of normal cell types. The pran was next used to regulate the expression of a bioactive exon – a constitutively active form of human caspase 3 – to induce apoptosis in cancer cells. Further evaluation was performed in an orthotopic model of murine bladder cancer. ResultsThe average strengths of reporter expression had relative intensities of 99.8% (pran), 87.7% (pbrms1) and 55.8% (pmcm5) versus the strong Pcmv‐driven positive control. Comparisons of expression‐targeted reporter gene expression for these three promoters versus the clinically interesting promoter for the human telomerase reverse transcriptase gene (phTERT) yielded an improvement of 2‐ to 15‐fold. Following transfection, cell death was evident from morphologic observations and viability assays performed on the cancer cells lines, with little, if any, effects seen when the same genes were delivered to normal cells. Cell viability was reduced by up to...
Source: The Journal of Gene Medicine - Category: Genetics & Stem Cells Authors: Tags: Research Article Source Type: research