Research Article

Improved Killing of Human High-Grade Glioma Cells by Combining Ionizing Radiation with Oncolytic Parvovirus H-1 Infection

Figure 4

Replication of parvovirus H-1 (H-1PV) in irradiated human high-grade glioma cells. FACS analysis of intracellular cytotoxic parvoviral protein NS-1 in short-term cultures of human gliosarcoma NCH-37 (a), human glioblastoma NCH-82 (b), and human glioblastoma NCH-89 (c) after infection with H-1PV. To analyse the influence of radiation therapy, glioma cells were irradiated with 10 Gy or transported to the accelerator but not exposed to IR (0 Gy). For early infection experiments, cells were infected at an MOI of 5 PFU/cell 24 hours post-IR (MOI 5-E) or mock-infected (MOCK); for late infection experiments cells were infected at an MOI of 5 PFU/cell 9 days post-IR (MOI 5-L). The short-term culture of in vivo irradiated recurrent glioblastoma NCH-307 (d) was infected with an MOI of 5 PFU/cell (MOI5) or mock-infected (MOCK). All cell cultures were harvested 24 hours p.i. and the percentage of cells positive for intracellular NS-1 was determined by FACS-analysis. (e) Detection of H-1PV RNA by RT-PCR. All cell lines except for NCH-307 were irradiated with 10 Gy. 24 hours post-IR and 24 postseeding for NCH-307, respectively, cells were infected with H-1PV at an MOI of 5 PFU/cell (MOI5). RNA was isolated 24 hours p.i. amplified by RT-PCR and compared with RNA of mock-infected cells (MOCK). For positive control, RNA of H-1PV infected unirradiated highly susceptible RG2 rat glioma cells was used.
(a) 𝑁 𝐶 𝐻 - 3 7
(b) 𝑁 𝐶 𝐻 - 8 2
(c) 𝑁 𝐶 𝐻 - 8 9
(d) 𝑁 𝐶 𝐻 - 3 0 7