Effects of antiangiogenic drugs on expression patterns of epigenetic pathway genes

BACKGROUND AND OBJECTIVE: To investigate the effects of antiangiogenic drugs on the transcription profile of acetylation genes in immortalized human retinal pigment epithelium cells (ARPE-19) in vitro. MATERIALS AND METHODS: This in vitro study evaluated the effect of antiangiogenic drugs on the expression of histone acetylation genes on immortalized ARPE-19 cell cultures. ARPE-19 cells were cultured, plated, and treated for 24 hours with aflibercept (Eylea; Regeneron, Tarrytown, NY), ranibizumab (Lucentis; Genentech, South San Francisco, CA), or bevacizumab (Avastin; Genentech, South San Francisco, CA) at one (1x) or two times (2x) the concentrations of the clinical intravitreal dose. Untreated cells were used as controls. RNA was isolated, and real-time quantitative reverse transcription polymerase chain reaction analysis was performed on individual samples to quantify expression levels of genes associated with epigenetic acetylation pathways: histone acetyltransferase 1 (HAT1) and histone deacetylases 1, 6, and 11 (HDAC1, HDAC6, and HDAC11). Differences in cycle thresholds (ΔΔCts) were obtained, and folds were calculated using the formula 2^{^}ΔΔ^Ct. Main outcome measures were expression levels of candidate genes in treated versus untreated samples. RESULTS: Compared with untreated cells, 1x ranibizumab-treated cells expressed higher levels of HDAC6, and 2x ranibizumab-treated cells expressed higher HDAC11 levels. Bevacizumab-treated (1x) cells had significant change in HDAC1, HDAC6, and HDAC11. In cultures treated with 2x bevacizumab, only HDAC11 expression levels were significantly affected compared with controls. Aflibercept-treated (1x) cells had changes in expression of HDAC1, HDAC6, and HDAC11. At 2x concentration, only HDAC11 was significantly changed. CONCLUSION: Our results show that antiangiogenic drugs can affect the transcription profile of genes regulating the histone acetylation status in ARPE-19 cells in vitro. This finding may have an implication in differential patient response to anti-vascular endothelial growth factor therapy by means of possible interactions between treatment and patient's epigenomic profile.