Abstract
Purpose: :
To evaluate and quantify cell cycle changes in choroidal endothelial cells exposed to varying doses of Bevacizumab in the presence of vascular endothelial growth factor (VEGF). Bevacizumab, a drug widely used in the treatment of neovascular age-related macular degeneration, choroidal neovascularization and proliferative diabetic retinopathy, neutralizes all isoforms of VEGF. However, the effect of intravitreal administration of Bevacizumab on choroidal cell cycle is not known.
Methods: :
Monkey choroidal endothelial RF/6A cells were treated with VEGF (50 ng/ml) and/or Bevacizumab (0.1-2 mg/ml) for 72h. Cell proliferation was measured with the WST-1 assay (Roche). Morphological changes were recorded by bright field microscopy of cells. Cell cycle changes in response to Bevacizumab were evaluated with Propidium Iodide (PI) staining.
Results: :
Bevacizumab (1 mg/ml or 2 mg/ml) alone produced a 4.81% or 5.42% decrease in cell proliferation compared to controls, respectively (p=0.05). Bevacizumab (1 mg/ml or 2 mg/ml) and VEGF (50 ng/ml) produced a 12.1% or 10.2% decrease in cell proliferation compared to controls, respectively. VEGF (50 ng/ml) produced a 7.7% increase in cell proliferation compared to controls. The morphology of cells was unchanged after treatment with Bevacizumab and/or VEGF compared to controls.The percentage of Bevacizumab (2 mg/ml) and VEGF (50 ng/ml) - treated cells in the G0/G1 phase increased compared to controls (64% compared to 52% in controls; p=0.05). The percentage of Bevacizumab (1, 1.5 mg/ml)-treated cells in G2/M phase was similar to controls (23.03% and 23.04%, respectively; 21% in controls). The cell cycle effects of Bevacizumab on choroidal endothelial cells were dose-dependent.
Conclusions: :
Bevacizumab inhibits VEGF and stabilizes choroidal endothelial cells in G0/G1 phase compared to VEGF enriched cells.
Keywords: choroid: neovascularization • choroid • vascular endothelial growth factor