A novel tumor-specific gene therapy for bladder cancer

Gene therapy has been successfully used to treat genetic diseases. Currently, much investigation involves the role of gene therapy in malignant tumors. One problem associated with the retroviral system used for gene therapy is its non-specificity. Herein a vector delivery system is described, using human telomerase reverse transcriptase (hTRT) promotor, which can specifically affect telomerase-positive tumor cells while sparing nearby telomerase-negative cells. By combining a self-containing Cre/loxP site-specific recombination system into the design, this vector will destroy telomerase-positive, p53-negative tumor cells, while sparing normal cells which are telomerase-positive with wild type p53 (such as activated lymphocytes). This vector design appears especially suited to bladder transitional cell carcinoma, because of easy access transurethrally and high rate of local recurrence, and biologically secondary to high proportion of telomerase activity and p53 dysfunction.