Recombinant Semliki Forest Virus infects and kills human prostate cancer cell lines and prostatic duct epithelial cells ex vivo

Semliki Forest Virus (SFV) is a broad host range RNA virus capable of high- level recombinant protein expression and apoptosis induction in many cell t ypes. We have successfully used a recombinant, replication deficient SFV ve ctor to express the LacZ marker gene product in seven human prostate cell l ines, as well as in human prostate tissue explants. Flow cytometry revealed that 40-60% of PPC-1 prostate cancer cells died 24-72 h after infection wi th SFV-LacZ virus. Most human prostate cancer cell lines expressed high lev els of recombinant protein. Infection of human prostate tissue ex vivo led to similarly high expression levels but the recombinant beta-galactosidase was confined to duct epithelial cells. Infection of cell and tissue culture s resulted in detachment of adherent cells from the culture surface and det achment of epithelial cells from the basement membrane of tissue. Our resul ts indicate that SFV may be useful in targeting recombinant protein express ion and apoptosis to prostatic duct epithelial cells.