A novel tumor-specific gene therapy for bladder cancer

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