Strategies used in the clinical trials of gene therapy for cancer
Thekkuttuparambil Ananthanarayanan Ajith
Advances in understanding and manipulating genes have set the stage for scientists to alter a person’s genetic material to prevent or treat diseases. Over the past decade, somatic gene therapy has been increasingly applied in clinical trials where the genetic material (DNA and RNA) introduced into a person’s cell. Mutation and inactivation of the tumor suppressor genes are the unified concept of the development of tumor in humans. Therefore, researchers have discovered potential of gene therapies in the treatment of cancer. Among the clinical trials of gene therapy conducted so far, approximately 66% were for the treatment of cancer which includes cancer of prostate, head and neck, kidneys, lungs, breast and skin. Introducing a wild type p53 gene, enhancing the immune system to protect against the cancer cells, enhancing the apoptosis of cancer cells and inhibiting the process of angiogenesis in the tumor are some of the clinical trials that are achieved through the gene therapy. Broad spectrum of delivery constructs, including viral vectors, liposomes, cationic polymers and dendrimers, cell-penetrating peptides, semiconductor quantum dots, and gold and magnetic nanoparticles have been investigated. A well designed vector is the most forward approach to increase the safety of gene therapy. Though, Gendicine™ and Oncorine™ have been marketed, gene therapy is still in its infancy stages in cancer research. More experimental and clinical trials using well-designed and effective doses of vectors are needed to ensure the therapeutic efficacy of gene therapy for its clinical use against a wide variety of cancers. This review article discusses about the various strategies used in clinical trials of gene therapy for cancer.
Keywords: Apoptosis; angiogenesis; gene therapy; immunomodulation; mutation; tumor suppressor gene