Abstract
Accumulated studies have highlighted that the dysregulation of microRNAs (miRNAs) in retinoblastoma (RB) is a leading cause for tumourigenesis and tumour development. Therefore, the elucidation of the expression, functional roles and underlying mechanisms of miRNAs in RB will help the development of promising therapeutic methods to improve the prognosis of RB patients. The aim of this study was to detect miRNA‑758 (miR‑758) expression in RB tissues and cell lines, and to determine the effects and underlying mechanisms of miR‑758 on RB progression. The results demonstrated that miR‑758 was downregulated in both RB tissues and cell lines. In vitro functional experiments revealed that upregulation of miR‑758 inhibited cell proliferation, migration and invasion, and induced apoptosis in RB. In addition, paired box protein 6 (PAX6) was a direct target gene of miR‑758 in RB. Furthermore, PAX6 was upregulated in RB tissues, and this upregulation was inversely associated with the expression level of miR‑758. In addition, PAX6 reintroduction abrogated the tumour‑suppressive effects of miR‑758 overexpression on RB cell proliferation, migration, invasion and apoptosis. Furthermore, miR‑758 overexpression inactivated the PI3K/Akt pathway in RB cells by inhibiting PAX6. In conclusion, our current study provided sufficient evidence to demonstrate that miR‑758 inhibits the progression of RB by directly targeting PAX6 and regulating the PI3K/Akt pathway, thereby suggesting that this miRNA may be developed as a therapeutic target for treating patients with RB.