Sinusoidal endothelial cells and vascular endothelial growth factor are key players in an in-vitro model of oxaliplatin-induced sinusoidal obstruction syndrome

Abstract

Introduction: Oxaliplatin as part of systemic treatment for colorectal liver metastases (CLM) has been associated with the development of sinusoidal obstruction syndrome (SOS). While the role of hepatocytes and sinusoidal endothelial cells in the pathogenesis of SOS remains unclear, bevacizumab, an inhibitor of vascular endothelial growth factor (VEGF), is considered to prevent SOS. The aim of this study was to analyse cytotoxicity of oxaliplatin-based treatment regimens and expression of VEGF in an in-vitro model of SOS. Methods: Human hepatic sinusoidal endothelial cells (HHSEC) and HepG2 cells (human liver cancer cell line) were incubated with either oxaliplatin, bevacizumab or both for 12 to 60 hours. Cytotoxicity was analysed by CellTox green assay. Protein levels of VEGF and matrix metallopeptidase 9 (MMP9) were measured by ELISA. Cytoskeletal changes were identified by F-Actin immunofluorescence. Cell proliferation and migration were analysed using a scratch assay. Liver transaminases were measured by photometric determination. Results: Supernatant of HHSEC had increased VEGF levels after 48h hours of treatment with oxaliplatin compared to supernatant of HepG2 cells (382.2 vs. 23.73 pg/mL). Additional administration of bevacizumab on HHSEC facilitated a significantly decreased cytotoxicity compared to oxaliplatin alone (4.13 vs. 5.52 RFU, P=0.004). Conclusion: Our findings suggest that oxaliplatin has a major impact on HHSEC resulting in increased expression of VEGF as a key player of oxaliplatin-induced SOS. Additionally, anti-VEGF seems to protect the HHSEC from the cytotoxic effect of oxaliplatin. These results may improve our understanding of the pathogenesis of SOS and optimize multimodal treatment of patients with CLM.