Activation of LncRNA FOXD2-AS1 by H3K27 acetylation regulates VEGF-A expression by sponging miR-205-5p in recurrent pterygium.

LncRNA FOXD2-AS1 is abnormally expressed in many diseases. However, the molecular mechanisms whereby FOXD2-AS1 is involved in recurrent pterygium remain unknown. Here, qRT-PCR was performed to quantify FOXD2-AS1 expression, while CCK-8, flow cytometer and neoplasm xenograft assays were used to investigate its function. Dual-luciferase reporter, RIP and RNA pull-down assays were conducted to address the relationship between FOXD2-AS1, miR-205-5p and VEGF-A, while ChIP assays were used to detect H3K27 acetylation at the FOXD2-AS1 promoter. FOXD2-AS1 expression was up-regulated in recurrent pterygium tissues. Moreover, a high FOXD2-AS1 expression was associated with advanced stages, increased microvessel density and shorter recurrent-free survival. In addition, ROC analysis showed that FOXD2-AS1 is a valid predictor of recurrent pterygium. Furthermore, we show that FOXD2-AS1 induced proliferation and inhibited apoptosis in a cell line derived from recurrent pterygia (HPF-R) at least partially through the regulation of the miR-205-VEGF pathway. In addition, the up-regulation of FOXD2-AS1 was attributed to the H3K27 acetylation at the promoter region. In conclusion, FOXD2-AS1 is activated via its H3K27 acetylation and regulates VEGF-A expression by sponging miR-205-5p in recurrent pterygium. Our results may provide a basis for the development of new therapeutic targets and biomarkers for recurrent pterygium.