Limits...
γ₁34.5-deleted HSV-1-expressing human cytomegalovirus IRS1 gene kills human glioblastoma cells as efficiently as wild-type HSV-1 in normoxia or hypoxia.

Friedman GK, Nan L, Haas MC, Kelly VM, Moore BP, Langford CP, Xu H, Han X, Beierle EA, Markert JM, Cassady KA, Gillespie GY - Gene Ther. (2014)

Bottom Line: Increased activation of mitogen-activated protein kinase p38 and its substrate heat-shock protein 27 (Hsp27) was seen after viral infection in normoxia compared with hypoxia.Hsp27 knockdown or p38 inhibition reduced virus recovery, indicating that the p38 pathway has a role in the reduced efficacy of the γ(1)34.5-deleted virus in hypoxia.Taken together, these findings demonstrate that chimeric HCMV/HSV-1 efficiently targets both CD133+ GSCs and glioma cells in hypoxia.

View Article: PubMed Central - PubMed

Affiliation: Brain Tumor Research Program, Division of Pediatric Hematology and Oncology, Department of Pediatrics, University of Alabama at Birmingham, Birmingham, AL, USA.

ABSTRACT
Pathophysiological hypoxia, which fosters the glioma stem-like cell (GSC) phenotype, is present in high-grade gliomas and has been linked to tumor development, invasiveness and resistance to chemotherapy and radiation. Oncolytic virotherapy with engineered herpes simplex virus-1 (HSV-1) is a promising therapy for glioblastoma; however, the efficacy of γ(1)34.5-deleted HSVs, which have been used in clinical trials, was diminished in hypoxia. We investigated the ability of a chimeric human cytolomegalovirus (HCMV)/HSV-1 virus, which expresses the human CMV protein kinase R evasion gene IRS1 and is in preparation for clinical trials, to infect and kill adult and pediatric patient-derived glioblastoma xenografts in hypoxia and normoxia. Infectivity, cytotoxicity and viral recovery were significantly greater with the chimeric virus compared with the γ(1)34.5-deleted virus, regardless of oxygen tension. The chimeric virus infected and killed CD133+ GSCs similarly to wild-type HSV-1. Increased activation of mitogen-activated protein kinase p38 and its substrate heat-shock protein 27 (Hsp27) was seen after viral infection in normoxia compared with hypoxia. Hsp27 knockdown or p38 inhibition reduced virus recovery, indicating that the p38 pathway has a role in the reduced efficacy of the γ(1)34.5-deleted virus in hypoxia. Taken together, these findings demonstrate that chimeric HCMV/HSV-1 efficiently targets both CD133+ GSCs and glioma cells in hypoxia.

Show MeSH

Related in: MedlinePlus

In vivo infectivity, as measured by GFP expression (green), 24 hours post-inoculation of 1×107 PFU of ICP34.5- or C154 virus in GBM-XD456MG cells (DAPI; blue) grown in the right cerebral hemisphere of nude mice. Areas of hypoxia are marked by carbonic anhydrase 9 (CA9; red). Controls were injected with saline. Rabbit IgG was used as a negative control. Photos were taken microscopically with a 10× objective and representative of 10 sections.
© Copyright Policy
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4383690&req=5

Figure 5: In vivo infectivity, as measured by GFP expression (green), 24 hours post-inoculation of 1×107 PFU of ICP34.5- or C154 virus in GBM-XD456MG cells (DAPI; blue) grown in the right cerebral hemisphere of nude mice. Areas of hypoxia are marked by carbonic anhydrase 9 (CA9; red). Controls were injected with saline. Rabbit IgG was used as a negative control. Photos were taken microscopically with a 10× objective and representative of 10 sections.

Mentions: To confirm the in vitro finding of improved infectivity of C154 compared to the 34.5-deleted virus, in vivo virus infectivity of GBM-XD456 growing in the right cerebral hemisphere of athymic nude mice was characterized by fluorescent immunohistochemistry (IHC) for GFP expression in hypoxic areas of the tumor, as measured by carbonic anhydrase 9 (CA9) expression, 24 hours post-inoculation. This time point was chosen to allow for ample time for GFP production, which occurs with immediate-early gene expression, but prior to cell lysis. More GFP expression was seen after C154 infection compared to ICP34.5- virus in areas with and without CA9 expression (Figure 5), suggesting superior C154 infectivity of GBM-XD456 cells in hypoxic and less-hypoxic areas of the tumor.


γ₁34.5-deleted HSV-1-expressing human cytomegalovirus IRS1 gene kills human glioblastoma cells as efficiently as wild-type HSV-1 in normoxia or hypoxia.

Friedman GK, Nan L, Haas MC, Kelly VM, Moore BP, Langford CP, Xu H, Han X, Beierle EA, Markert JM, Cassady KA, Gillespie GY - Gene Ther. (2014)

In vivo infectivity, as measured by GFP expression (green), 24 hours post-inoculation of 1×107 PFU of ICP34.5- or C154 virus in GBM-XD456MG cells (DAPI; blue) grown in the right cerebral hemisphere of nude mice. Areas of hypoxia are marked by carbonic anhydrase 9 (CA9; red). Controls were injected with saline. Rabbit IgG was used as a negative control. Photos were taken microscopically with a 10× objective and representative of 10 sections.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4383690&req=5

Figure 5: In vivo infectivity, as measured by GFP expression (green), 24 hours post-inoculation of 1×107 PFU of ICP34.5- or C154 virus in GBM-XD456MG cells (DAPI; blue) grown in the right cerebral hemisphere of nude mice. Areas of hypoxia are marked by carbonic anhydrase 9 (CA9; red). Controls were injected with saline. Rabbit IgG was used as a negative control. Photos were taken microscopically with a 10× objective and representative of 10 sections.
Mentions: To confirm the in vitro finding of improved infectivity of C154 compared to the 34.5-deleted virus, in vivo virus infectivity of GBM-XD456 growing in the right cerebral hemisphere of athymic nude mice was characterized by fluorescent immunohistochemistry (IHC) for GFP expression in hypoxic areas of the tumor, as measured by carbonic anhydrase 9 (CA9) expression, 24 hours post-inoculation. This time point was chosen to allow for ample time for GFP production, which occurs with immediate-early gene expression, but prior to cell lysis. More GFP expression was seen after C154 infection compared to ICP34.5- virus in areas with and without CA9 expression (Figure 5), suggesting superior C154 infectivity of GBM-XD456 cells in hypoxic and less-hypoxic areas of the tumor.

Bottom Line: Increased activation of mitogen-activated protein kinase p38 and its substrate heat-shock protein 27 (Hsp27) was seen after viral infection in normoxia compared with hypoxia.Hsp27 knockdown or p38 inhibition reduced virus recovery, indicating that the p38 pathway has a role in the reduced efficacy of the γ(1)34.5-deleted virus in hypoxia.Taken together, these findings demonstrate that chimeric HCMV/HSV-1 efficiently targets both CD133+ GSCs and glioma cells in hypoxia.

View Article: PubMed Central - PubMed

Affiliation: Brain Tumor Research Program, Division of Pediatric Hematology and Oncology, Department of Pediatrics, University of Alabama at Birmingham, Birmingham, AL, USA.

ABSTRACT
Pathophysiological hypoxia, which fosters the glioma stem-like cell (GSC) phenotype, is present in high-grade gliomas and has been linked to tumor development, invasiveness and resistance to chemotherapy and radiation. Oncolytic virotherapy with engineered herpes simplex virus-1 (HSV-1) is a promising therapy for glioblastoma; however, the efficacy of γ(1)34.5-deleted HSVs, which have been used in clinical trials, was diminished in hypoxia. We investigated the ability of a chimeric human cytolomegalovirus (HCMV)/HSV-1 virus, which expresses the human CMV protein kinase R evasion gene IRS1 and is in preparation for clinical trials, to infect and kill adult and pediatric patient-derived glioblastoma xenografts in hypoxia and normoxia. Infectivity, cytotoxicity and viral recovery were significantly greater with the chimeric virus compared with the γ(1)34.5-deleted virus, regardless of oxygen tension. The chimeric virus infected and killed CD133+ GSCs similarly to wild-type HSV-1. Increased activation of mitogen-activated protein kinase p38 and its substrate heat-shock protein 27 (Hsp27) was seen after viral infection in normoxia compared with hypoxia. Hsp27 knockdown or p38 inhibition reduced virus recovery, indicating that the p38 pathway has a role in the reduced efficacy of the γ(1)34.5-deleted virus in hypoxia. Taken together, these findings demonstrate that chimeric HCMV/HSV-1 efficiently targets both CD133+ GSCs and glioma cells in hypoxia.

Show MeSH
Related in: MedlinePlus