Circular RNA has_circ_0000527 participates in proliferation, invasion and migration of retinoblastoma cells via miR-646/BCL-2 axis.

Retinoblastoma (RB) is one of the most common primary intraocular malignancies in children. Emerging researches have shown that circular RNAs (circRNAs) play critical roles in a variety of cancers. As a novel circRNA, the function of circ_0000527 in RB remains unknown. In this work, expression level of circ_0000527 and miR-646 in RB tissues and cell lines were detected by quantitative real-time polymerase chain reaction (qRT-PCR). RB cell lines (SO-Rb50 and WERI-Rb-1) were used as cell models in functional experiments. CCK-8 assay, TUNEL assay and transwell assay were employed to detect the biological influence of circ_0000527 and miR-646 on cancer cells in vitro. qRT-PCR, luciferase reporter assay, RIP assay and western blot were used for exploring the interactions among circ_0000527, miR-646 and BCL-2. It was demonstrated that expression level of circ_0000527 in RB samples was significantly up-regulated compared to normal tissues, while miR-646 was markedly down-regulated. Overexpression of circ_0000527 promoted the viability, migration and invasion of RB cells, while miR-646 transfection had the opposite effects. Circ_0000527 sponged miR-646 to regulate the expression of BCL-2. In conclusion, circ_0000527 could promote the development of RB by indirectly modulating BCL-2 via absorbing miR-646. SIGNIFICANCE OF THE STUDY: Expression level of circ_0000527 in RB samples was significantly up-regulated compared to normal tissues, while miR-646 was markedly down-regulated. Overexpression of circ_0000527 promoted the viability, migration and invasion of RB cells, while miR-646 transfection had the opposite effects. Circ_0000527 sponged miR-646 to regulate the expression of BCL-2.