Cancer Gene Therapy

Abstract

Overview Gene therapy of cancer has shown increasingly encouraging results and now is ready to enter mainstream oncological practice. Gene transfer can modify the cellular phenotype and behavior of malignant cells or host immune cells in order to modulate tumor responses. In this chapter, we discuss both of the above approaches and describe the vector systems that are able to produce the intended genetic modifications. We describe current clinical successes of gene therapy and outline the challenges it has yet to overcome. The success of either approach depends on efficient, safe gene transfer with vectors that can either integrate (e.g., retroviral, lentiviral, or adeno‐associated viral, or transposons) or not integrate (e.g., adenoviral, herpesviral, or nonviral) into the human genome. To date, reversing the phenotype of all stem cells within a cancer has not proven feasible, and infectious cytolytic viral therapy has not yet had a significant impact in the clinic. Enhancement of active cancer immunotherapy with forced expression of antigens and cytokines or the enhancement of adoptive immunotherapy by engineering T lymphocytes with specific T‐cell receptors and chimeric antigen receptors shows greater immediate promise, although ultimately a combination of multiple approaches will prove optimal.