Gene therapy approaches for the selective killing of cancer cells

This review describes gene therapy strategies that take advantage of defective signal transduction pathways to selectively kill cancer cells without adversely affecting normal cells. The distinctive features of cancer cells currently exploited by gene therapy include mitosis, cell permissiveness to infection, specific protease activity, and the activity of the p53, Rb/E2F and wnt/catenin signal transduction pathways. In most cases, proof of concept has been obtained in vitro and in vivo, but only a few approaches made it to the clinic. Overall, the clinical success rate has been disappointing and it is concluded that the gene therapy of cancer requires more innovation and hard work before its potential can be fully realized.