A lentiviral vector expressing a fusogenic glycoprotein for cancer gene therapy

The gibbon ape leukaemia virus envelope fusogenic membrane glycoprotein (GA LV FMG) is a highly potent cytotoxic gene with great potential for use in c ancer gene therapy. Here, we show that production of a VSV-G pseudotyped le ntiviral vector expressing GALV FMG reconciles the requirements of viral pr oduction with the cytotoxic effects of GALV in human cells and has high tit res on both dividing and quiescent tumour cells. Direct intratumoral inject ion of these stocks eradicated progressively growing human tumour xenograft s. The potent bystander effect of the FMG transgene is a major contributor to the success of this approach but immunological activation may also be a factor. To our knowledge, this is the first demonstration in vivo of the po tential both of FMG and lentiviral vectors for cancer gene therapy and high lights the importance of exploring different Vector systems to complement t he biological properties of the therapeutic transgene.