ABSTRACT
Virally mediated gene transfer strategies are being widely explored for the treatment of many cancers (Jolly, 1994; Eck and Wilson, 1995; Weitzman et at., 1995). Indeed such strategies are extremely flexible with respect to the function of the transferred gene and provide a seemingly limitless number of therapeutic avenues. Nonetheless, gene transfer for the treatment of cancer (or any other disease) has yet to be reduced to practice, in large part because of the limitations of the vectors employed. Several major vector design issues have been identified in preclinical work, including targeting of the vector to the tumor, obtaining efficient gene transfer, and limiting the host immune response to the vector. While significant advances have been made in addressing these problems, no vector system has overcome all of them satisfactorily.
