Figure 5
Doxycycline enhances viral replication and gene expression after treatment of multiple tumor cell lines with oncolytic vaccinia strain vvDD. (a) Different tumor cell lines were infected (Multiplicity of Infection of 1.0 PFU/cell) with oncolytic vaccinia strain vvDD expressing luciferase, with and without the presence of 1 μgml−1 doxycycline. Viral gene expression was determined at indicated times by bioluminescence imaging. Cell lines HeLa, HT29, OVCAR3, H596, OVCAR8, MDA-MB-231, DLD1 and HCT116 all displayed significantly increased gene expression at 48 h after infection, (P<0.05). (b) Viral plaque assays confirmed the increased gene expression correlated with viral replication for selected cell lines at 48 h. (c) The same gene expression assay was performed on the non-tumor (immortalized, non-transformed) cell line MRC-5. (d) Viral replication was also determined by plaque assay r in human CIK cells.
