Retrovirus mediated expression of interleukins for the gene therapy of cancer

Cytokine gene transfer ex vivo into tumor cells has been used to prepare immunogenic vaccines for treating a variety of animal tumors and, more recently, of human tumors as well. In this review we summarize this work first by describing the retroviral vectors that have been utilized for transducing cytokine genes into neoplastic cells. An analysis of the different animal tumor systems in which such a therapeutic approach has been adopted and of its results along with the mechanisms of tumor growth inhibition and therapeutic effect is then carried out. Finally, the more recent application of cytokine gene-based cellular vaccines in human tumors is reported with a discussion of the pros and cons that have been generated by this type of investigations.