Purpose: To examine the cytotoxic effects of bevacizumab on the viability and metabolism of human corneal epithelial cells (HCEpCs) and human corneal endothelial cells (HCEnCs), as well as human retinal pigment epithelial (ARPE-19) cells for comparison.
Methods: Immortalized cell lines of HCEpCs, HCEnCs, and ARPE-19 cells were exposed to clinically relevant concentrations of bevacizumab (0.313-5.00 mg/mL). The ApoTox-Glo Triplex Assay was used to assess cell viability, cytotoxicity, and apoptosis, and the Mitochondrial ToxGlo Assay was used to assess cell membrane integrity and adenosine triphosphate (ATP) levels after a 24-hour treatment period.
Results: Across all three cell types, we observed similar results of a decrease in cell viability at 5.00 mg/mL (P < 0.05) and an increase in cytotoxicity at 5.00 mg/mL (P < 0.05), whereas apoptotic activity remained unchanged (P > 0.05), which is a profile consistent with cells undergoing primary necrosis at high concentrations. Additionally, cell membrane integrity was compromised at 5.00 mg/mL (P < 0.05), whereas no decrease in ATP levels were observed (P > 0.05). Thus, no interference with mitochondrial oxidative phosphorylation in ATP production was seen, and the cells were able to maintain normal metabolic levels at high concentrations of bevacizumab.
Conclusions: HCEpCs, HCEnCs, and ARPE-19 cells experience a decrease in viability and undergo primary necrosis when exposed to bevacizumab at a concentration of 5.00 mg/mL; however, they are able to maintain normal metabolism and mitochondrial function at the high concentrations used for the treatment of corneal neovascularization.
Translational relevance: This study provides safety data on the concentrations of bevacizumab injected intravitreally and complements clinical data showing toxicity of topical bevacizumab on corneal epithelial and endothelial cells.