Affiliations: [a] Department of Pharmacy, The Central Hospital of Linyi, Yishui, Shangdong, China | [b] Department of Imaging, Yantai Yuhuangding Hospital, Yantai, Shangdong, China | [c] Department of Ophthalmology, The Affiliated Hospital of Qingdao University, Qingdao, Shangdong, China | [d] Department of Nuclear medicine, The Affiliated Hospital of Qingdao University, Qingdao, Shangdong, China
Abstract: BACKGROUND AND OBJECTIVES: MicroRNA (miR-221/222) is frequently overexpressed in many cancers and is associated with poor prognosis. However, the role of miR-221/222 in retinoblastoma (RB) remains unclear. This study aimed to detect the clinical significance of miR-221/222 in RB patients and explore its role in RB cells in vitro. METHODS: Expression of miR-221/222 was assessed in fresh RB tissue collected from 64 eyes and normal retinal tissues from 18 unrelated donor cadaver eyes by quantitative real time RT-PCR analysis (qRT-PCR), and correlated with the histopathological findings. Human RB Y79 cells were transfected with miR-221/222 precursors or inhibitors to overexpress or downregulate miR-221/222 expression, respectively, using Lipofectamine 2000 reagent. The biological effects of miR-221/222 were then assessed by cell viability assays, colony formation assays, apoptosis detection assays, Matrigel® invasion assays, and wound-healing assays. RESULTS: Higher miR-221/222 expression was detected in RB tissues compared to that of the normal retinal tissues (p< 0.001). Higher miR-221/222 expression was correlated with invasion in patients with RB. Targeting of miR-221/222 induced apoptosis and inhibited Y79 cell proliferation, migration, and invasion in vitro. However, overexpression of miR-221/222 promoted Y79 cell proliferation, migration, and invasion in vitro. CONCLUSIONS: Overexpression of miR-221/222 was associated with tumor invasiveness in patients with RB. The miR-221/222 cluster might be used as a potential therapeutic strategy in clinical practice.
