Novel RNA Virus System for Selective Killing of Breast Cancer Cells

摘要

The goals of this project were to develop a novel method for targeting an SV5 infection to breast cancer cells and to control the virus mediated killing by: (1) engineering SV5 to express an anti-HER-2 single chain antibody in place of the normal HN attachment protein, and (2) to engineer SV5 to express the herpes simplex thymidine kinase. The gene encoding an anti-HER-2 single chain antibody (sFv) linked to HN was inserted into the SV5 infectious clone in place of the gene for HN and virus was recovered. Initial studies demonstrated expression of the sFv-HN chimeric protein in cells infected with the rSV5. To determine if SV5 could be used for controlled cell killing, a second rSV5 was generated to encode the thymidine kinase gene. Cells infected with rSV5-TK showed a time-dependent loss of viability when infected cells were cultured in the presence of the prodrug ganciclovir (GCV) while no significant toxicity was observed in the absence of prodrug. Titration experiments showed that rSVS-TK plus GCV resulted in cell death for all mouse and human cell lines tested. The recovery of an rSV5 with a novel attachment protein and controlled cell killing by a rSV5-TK support the further development of SVS as a therapeutic vector for targeted killing of cancer cells.