Hsa_circ_0119412 Contributes to Development of Retinoblastoma by Targeting miR-186-5p/ELK4 Axis.

Increasing evidences indicate the crucial role of circRNAs in tumorigenesis, but little is understood about their molecular mechanism in retinoblastoma (RB). This paper was designed for exploring the circ_0119412 function in cases with RB and the potential mechanism. RT-qPCR was utilized to ascertain circ_0119412 and miR-186-5p levels in RB tissues and cells, and western blotting was used to quantify ELK4 in RB cells. In addition, CCK-8 and scratch assays were carried out for evaluation of cell proliferation and migration, respectively. Apoptosis-related proteins levels (Bax and Bcl-2) were measure by western blotting. Tumor growth in vivo was detected utilizing xenograft tumor experiment. The targeting relationship between circ_0119412, miR-186-5p, and ELK4 was validated using a dual-luciferase reporter assay and an RNA immunoprecipitation (RIP) assay. In RB tissues and cells, Circ_0119412 and ELK4 expression were upregulated, while miR-186-5p expression was downregulated. In vitro assay revealed that downregulating circ_0119412 accelerated the cell apoptosis of RB cells and slowed down their migration and proliferation, and the in vivo assay indicated that circ_0119412 downregulation reduced the weight and volume of tumor in nude mice. In addition, miR-186-5p interference promoted the malignant behavior of RB cells, while ELK4 silencing showed an opposite trend. Mechanically, circ_0119412 can promote RB malignant phenotypes via miR-186-5p/ELK4 axis. Circ_0119412 was found to be upregulated in RB, and could accelerate the progression of RB via the miR-186-5p/ELK4 axis, indicating circ_0119412 may serve a promising clinical therapeutic target of RB.