Cell cycle regulation by bevacizumab in ARPE-19 human retinal pigment epithelial cells

Abstract

Abstract. Bevacizumab, a recombinant humanized monoclonal antibody, binds vascular endothelial growth factor (VEGF) and inhibits its interaction with receptors found on endothelial cells. Bevacizumab has been increasingly used as an off-label treatment for exudative age-related macular degeneration (AMD). Whether or not bevacizumab is capable of arresting the growth of human retinal pigment epithelial cells remains to be clarified. In this study, flow cytometry was used to evaluate whether bevacizumab markedly induced the G 1 /S phase arrest. The G 1 /S phase cycle-related protein analysis demonstrated that the expression of cyclin-dependent kinase (CDK)2, 4 and 6 and of cyclin D and E, as well as the phosphorylation of retinoblastoma tumor suppressor protein (ppRB) production were found to be markedly reduced by bevacizumab. By contrast, the protein levels of p53, p16, p21 and p27 were increased in bevacizumab-treated ARPE-19 cells (a human retinal pigment epithelial cell line). These events of G 1 /S arrest induced by bevacizumab in ARPE-19 cells suggest that a preventive effect of bevacizumab exists in AMD.

Role of the Cell Cycle Re-Initiation in DNA Damage Response of Post-Mitotic Cells and Its Implication in the Pathogenesis of Neurodegenerative Diseases

“…The proteomic analysis of AMD patients revealed an increased expression of cell growth factors, including fibroblast growth factor (FGF) and hepatocyte growth factor (HGF) as well as proliferating cell nuclear antigen (PCNA), which plays a role in proliferation and cell cycle regulation 71. Bevacizumab, an antibody binding vascular endothelial growth factor (VEGF) used in the off-label treatment for AMD, caused cell cycle arrest in vitro and reduced the expression of G1/S phase cycle-related proteins, including CDK2, 4 and 6 and cyclin D and E, as well as the phosphorylation of Rb 72. Consistently, the levels of negative cell cycle regulators including p53, p16, p21 and p27 were increased in bevacizumab-treated cells in vitro.The increase in DNA damage was demonstrated to accompany neurodegenerative diseases, including an increase in DNA strand breaks in AD and HD, 8-oxoguanine lesions in ALS and the accumulation of mitochondrial DNA damage in PD [72][73][74][75][76].…”

“…Bevacizumab, an antibody binding vascular endothelial growth factor (VEGF) used in the off-label treatment for AMD, caused cell cycle arrest in vitro and reduced the expression of G1/S phase cycle-related proteins, including CDK2, 4 and 6 and cyclin D and E, as well as the phosphorylation of Rb 72. Consistently, the levels of negative cell cycle regulators including p53, p16, p21 and p27 were increased in bevacizumab-treated cells in vitro.The increase in DNA damage was demonstrated to accompany neurodegenerative diseases, including an increase in DNA strand breaks in AD and HD, 8-oxoguanine lesions in ALS and the accumulation of mitochondrial DNA damage in PD [72][73][74][75][76]. DNA damage, particularly of oxidative origin, showed a high correlation with aging and may play a role in a gradual loss of the cell cycle re-initiation in DNA damage response of postmitotic cells and its implication in the pathogenesis of neurodegenerative diseases (doi: 10.1089/rej.2015.1717) This article has been peer-reviewed and accepted for publication, but has yet to undergo copyediting and proof correction.…”

Mini‐αA Upregulates the miR‐155‐5p Target Gene CDK2 and Plays an Antiapoptotic Role in Retinal Pigment Epithelial Cells during Oxidative Stress

“…CDK2 belongs to the CDK serine/threonine kinase family and is an important regulator of G 1 / S -phase conversion. Bevacizumab significantly reduces CDK2, CDK4, and CDK6 as well as cyclin D and E expression and has a preventive effect on AMD by blocking G 1 / S progression in ARPE-19 cells [ 41 ]. In addition, miR-34a inhibits RPE cell proliferation and migration by downregulating its target CDK2 and other cell cycle-related molecules [ 12 ].…”