,.
Invest Ophthalmol Vis Sci. 2020 Mar 9;61(3):32. doi: 10.1167/iovs.61.3.32.
The pivotal role of microRNAs (miRNAs or miRs) has been proved in the pathogenesis of retinoblastoma. miR-224-3p is demonstrated to be involved in several tumors. However, the underlying mechanism of miR-224-3p in retinoblastoma is yet to be investigated. Therefore, this study was designed to identify the regulation of miR-224-3p in human retinoblastoma.
The expression pattern of miR-224-3p and large tumor suppressor 2 (LATS2) in retinoblastoma was measured by reverse transcription quantitative polymerase chain reaction. Afterward, the interaction between miR-224-3p and LATS2 was identified using a dual luciferase reporter gene assay. Next, gain-of-function and loss-of-function approaches were employed to examine the effects of miR-224-3p and LATS2 as well as their interaction on cell apoptosis, proliferation and angiogenesis abilities, and tumorigenesis. Whether the Hippo-YAP signaling pathway was involved in tumorigenesis was analyzed by determining downstream genes.
LATS2 was downregulated in retinoblastoma, and its overexpression promoted apoptosis and suppressed proliferation of retinoblastoma cells. miR-224-3p, highly expressed in retinoblastoma, inhibited the expression of its target gene LATS2, which inhibited activation of the Hippo-YAP signaling pathway. Suppression of miR-224-3p promoted apoptosis while suppressing the proliferation of retinoblastoma cells and angiogenesis. Tumor progression induced by upregulation of miR-224-3p was diminished by restoration of LATS2. It was observed that tumor growth and angiogenesis were reduced by depleted miR-224-3p in the animal experiments.
The present study suggests that miR-224-3p targets LATS2 and blocks the Hippo-YAP signaling pathway activation, thus preventing the progression of retinoblastoma, which could be a new therapeutic target for retinoblastoma.
微小 RNA（miRNA 或 miR）在视网膜母细胞瘤的发病机制中起着关键作用。miR-224-3p 被证明参与了几种肿瘤的发生。然而，miR-224-3p 在视网膜母细胞瘤中的潜在机制尚未得到研究。因此，本研究旨在确定 miR-224-3p 在人视网膜母细胞瘤中的调控作用。
采用逆转录定量聚合酶链反应检测 miR-224-3p 和大肿瘤抑制因子 2（LATS2）在视网膜母细胞瘤中的表达模式。随后，通过双荧光素酶报告基因检测鉴定 miR-224-3p 与 LATS2 之间的相互作用。接下来，采用功能获得和功能丧失方法研究 miR-224-3p 和 LATS2 及其相互作用对细胞凋亡、增殖和血管生成能力以及肿瘤发生的影响。通过确定下游基因来分析 Hippo-YAP 信号通路是否参与肿瘤发生。
LATS2 在视网膜母细胞瘤中下调，其过表达促进了视网膜母细胞瘤细胞的凋亡并抑制了增殖。在视网膜母细胞瘤中高表达的 miR-224-3p 抑制其靶基因 LATS2 的表达，从而抑制 Hippo-YAP 信号通路的激活。抑制 miR-224-3p 促进了视网膜母细胞瘤细胞的凋亡，同时抑制了增殖和血管生成。上调 miR-224-3p 诱导的肿瘤进展通过恢复 LATS2 而减弱。在动物实验中，观察到 miR-224-3p 耗竭减少了肿瘤生长和血管生成。
本研究表明，miR-224-3p 靶向 LATS2 并阻断 Hippo-YAP 信号通路的激活，从而阻止视网膜母细胞瘤的进展，这可能成为视网膜母细胞瘤的新治疗靶点。
