Circ_0000527 promotes the progression of retinoblastoma by regulating miR-646/LRP6 axis

Li Zhang,Lili Wang,Yujun Li,Yuwei Zou,Yunqing Chen,Yanxia Jiang,Yalin Lv,Jie Wu,Xiaoyan Ding

doi:10.1186/s12935-020-01396-4

Li Zhang, Lili Wang + Show 7 more

Open Access

https://doi.org/10.1186/s12935-020-01396-4

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Abstract

BackgroundResearches validate that circular RNAs (circRNAs) are dysregulated in a variety of malignancies and play an important role in regulating the malignant phenotype of tumor cells. Nevertheless, the role of circ_0000527 in retinoblastoma (RB) and its regulatory mechanisms remain largely unknown.MethodsReal-time PCR (RT-PCR) was used to detect circ_0000527 and miR-646 expression in RB tissues and cells. The LRP6 expression in RB cells was detected by Western blot. The relationship between circ_0000527 expression and the clinicopathological parameters of RB patients was analyzed. Cell proliferation, apoptosis and metastasis were monitored by cell counting kit-8 (CCK-8), flow cytometry, and Transwell assay. The dual-luciferase reporter gene assay and RIP assay were employed to verify the targeting relationship between circ_0000527 and miR-646, miR-646 and LRP6.ResultsCirc_0000527 was highly expressed in both RB and RB cell lines, whose high expression level and degree of differentiation were significantly correlated with the increase in cTNM staging level. Overexpression of circ_0000527 contributed to RB cell proliferation, migration, invasion and suppressed cell apoptosis, while knocking down circ_0000527 inhibited the above malignant biological behavior. The underlying mechanism suggested that functioning as a endogenous competitive RNA, circ_0000527 directly targeted miR-646 and positively regulated LRP6 expression.ConclusionCirc_0000527 enhances the proliferation and metastasis of RB cells by modulating the miR-646/LRP6 axis.

Highlights

Researches validate that circular RNAs are dysregulated in a variety of malignancies and play an important role in regulating the malignant phenotype of tumor cells
Circ_0000527/miR‐646 axis regulated the expression of lipoprotein receptor-related protein 6 (LRP6) To further explore the downstream molecules of miR646, we found through the TargetScan database that there was a potential base-complementary binding site between miR-646 and the 3′ untranslated region (3′UTR) of LRP6 (Fig. 6a)
To verify whether miR-646 binded to LRP6, dual luciferase reporter assay was carried out and the results showed that the miR646 mimics remarkably decreased the luciferase activity of the wild-type LRP6 3′UTR -WT reporter compared to

Summary

Introduction

Researches validate that circular RNAs (circRNAs) are dysregulated in a variety of malignancies and play an important role in regulating the malignant phenotype of tumor cells. Accumulating experiments indicate that circRNAs can function as biomarkers for cancer diagnosis and potential therapeutic targets [5]. The researches on expression function and mechanism of circRNA in RB are relatively rare. In renal clear cell carcinoma, miR-205-5p suppresses VEGFA expression and the PI3K/Akt/mTOR signaling pathway to function as a tumor suppressor [11]; miR-204-5p represses the proliferation and invasion of esophageal squamous cell carcinoma cells by suppressing IL-11 [12]. MiR-646 inhibits gastric cancer cell proliferation and EMT-induced metastasis by targeting and suppressing FOXK1 expression [13]. The expression and function of miR-646 in RB remains largely undefined

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