GENE-THERAPY FOR CANCER (PRESENT STATUS)

The present status of cancer gene therapy is reviewed here in short Tw o of the main gene therapy strategies for the treatment of cancer are discussed. The first main strategy is direct gene therapy which involv es insertion of a functioning tumor suppressor gene or suppression of expression of a known oncogene. The second main strategy is indirect g ene therapy which involves the insertion of a gene that modifies the c ell to be more immunogenic for the host. The main clinical gene therap y trials are reviewed in their present state, including the replacemen t of defective tumor suppressor genes, the insertion of suicide or sen sitivity genes, the insertion of prodrug-activating genes, and the use of virally directed enzyme prodrug therapies. Other topics discussed are the protection of stem cells from toxic effects of chemotherapy an d new directions for gene therapy of neoplastic disease.