Oxidative Stress in Canine Histiocytic Sarcoma Cells Induced by an Infection with Canine Distemper Virus Led to a Dysregulation of HIF-1α Downstream Pathway Resulting in a Reduced Expression of VEGF-B in vitro

• Published in: Viruses 2020-02, Vol.12 (2), p.200
• Main Authors: Armando, Federico, Gambini, Matteo, Corradi, Attilio, Giudice, Chiara, Pfankuche, Vanessa Maria, Brogden, Graham, Attig, Friederike, von Köckritz-Blickwede, Maren, Baumgärtner, Wolfgang, Puff, Christina
• Format: Article
• Language: English
• Subjects: angiogenesis; Animals; canine distemper virus; canine histiocytic sarcoma; Cell Line, Tumor; dh82; Distemper Virus, Canine - pathogenicity; Dogs; hif-1α; Histiocytic Sarcoma - virology; Hypoxia-Inducible Factor 1, alpha Subunit - genetics; Microarray Analysis; Oxidative Stress; Vascular Endothelial Growth Factor B - genetics; vegf-b; viral oncolysis
• ISSN: 1999-4915; 1999-4915
• DOI: 10.3390/v12020200

Histiocytic sarcomas represent malignant tumors which require new treatment strategies. Canine distemper virus (CDV) is a promising candidate due to its oncolytic features reported in a canine histiocytic sarcoma cell line (DH82 cells). Interestingly, the underlying mechanism might include a dysregulation of angiogenesis. Based on these findings, the aim of the present study was to investigate the impact of a persistent CDV-infection on oxidative stress mediated changes in the expression of hypoxia-inducible factor (HIF)-1α and its angiogenic downstream pathway in DH82 cells in vitro. Microarray data analysis, immunofluorescence for 8-hydroxyguanosine, superoxide dismutase 2 and catalase, and flow cytometry for oxidative burst displayed an increased oxidative stress in persistently CDV-infected DH82 cells (DH82Ond pi) compared to controls. The HIF-1α expression in DH82Ond pi increased, as demonstrated by Western blot, and showed an unexpected, often sub-membranous distribution, as shown by immunofluorescence and immunoelectron microscopy. Furthermore, microarray data analysis and immunofluorescence confirmed a reduced expression of VEGF-B in DH82Ond pi compared to controls. In summary, these results suggest a reduced activation of the HIF-1α angiogenic downstream pathway in DH82Ond pi cells in vitro, most likely due to an excessive, unusually localized, and non-functional expression of HIF-1α triggered by a CDV-induced increased oxidative stress.