MicroRNA-9 inhibits proliferation and Progression In retinoblastoma Cells By targeting PTEN

Background: Retinoblastoma (RB) is the most prevalent primary intraocular malignancy, which commonly occurs during infant and childhood.

Objective: Our study aimed to investigate whether microRNA-9 (miR-9) could regulate RB cells and its mechanism.

Methods: qRT-PCR analysis was used to detect the expression of miR-9. In addition, to detect the migration of RB cells, wound healing assay was conducted. Xenograft tumor models in nude mice were also established, in order to assess the effects of miR-9 on tumor growth. qRT-PCR, luciferase reporter assay and western blot analysis were used to detect the target of miR-9.

Results: Initially, the expression level of miR-9 was significantly decreased in the RB tissues and blood samples from patients with RB. qRT-PCR, luciferase reporter assay and western blot analysis were used to confirm that PTEN was the target genes of miR-9 and it was negatively regulated by miR-9. When the expression of miR-9 was up-regulated, the cell viability, proliferation, migration and tumor formation were significantly suppressed. Furthermore, the expression level of PTEN was decreased after transfection of miR-9 mimic. Taken together, these results indicated that miR-9 might suppress the cell viability, proliferation, migration and tumor formation in RB by inhibiting PTEN.

Conclusion: The in vitro and in vivo experiments demonstrated that miR-9 acts as a tumor suppressor function in RB cells and might serve as novel therapeutic targets for the treatment of RB.