Tumor suppressor genes as cancer therapeutics.

Cancer formation is a multistep process that involves the sequential activation of oncogenes as well as the inactivation of tumor suppressor genes often in the same clone of cells. These genetic changes generate concomitant phenotypic changes in the tumor cells that allow them to continue to survive and expand. Over the past decade a number of genetic alterations in oncogenes and tumor suppressor genes have been identified and extensive research has elucidated their role in cellular growth, differentiation and apoptosis. Targeting tumor suppressor gene pathways is an attractive therapeutic strategy in cancer. This review summarizes the current achievements and future prospects of gene replacement therapy. Methods of gene delivery are described, particularly those that have commonly be used in clinical trials. We discuss efforts to achieve tissue-specific gene delivery and improved efficiency of gene delivery.