G207, modified herpes simplex virus type 1, kills human pancreatic cancer cells in vitro

Pancreatic cancer is often fatal, and further effective therapeutic options are needed. This study was designed to assess whether the replication-rest ricted herpes simplex virus, G207, was effective in killing human pancreati c cancer cells in vitro. G207, a multimutated strain of herpes simplex viru s type 1 carrying lacZ reporter gene, is capable of efficient cytolytic gro wth in many dividing cells, including certain tumor cells, but not in nondi viding cells. Three human pancreatic cell lines, AsPC-1, MW PaCa-2, and BxP C-3, were infected with G207 at different multiplicities of infection. Afte r 24 hours, expression of the lacZ reporter gene was tested using a histoch emical X-gal assay. In addition, cell lines were infected with G207 for 24 to 48 hours; then the virus obtained from cell pellets and media supernatan t was used to infect Vero cells to obtain G207 titers by plaque assay. To a ssess whether increasing viral immediate early gene expression would improv e cytolysis and virus production, similar experiments were performed with t he addition of 0.5 mmol/L of hexamethylene bisacetamide (HMBA) 1 hour after viral infection. Finally, MTS cell viability assays were performed to meas ure viable cells at 24 to 96 hours post infection. The X-gal assay data rev ealed a viral dose-dependent beta-galactosidase expression, indicating G207 infectivity and expression of the lacZ reporter gene. Plaque assays demons trated a viral dose-dependent increase in plaque formation, indicating vira l production from all three cell lines. Ln addition, HMBA data indicated a modest increase in viral production. The MTS assay data indicated a dose-de pendent cytotoxicity for G207 in the cell lines tested. G207 infects, repli cates in, and is cytotoxic to the above-listed human pancreatic cell lines in vitro and warrants therapeutic evaluation in models of pancreatic cancer .