AIMS Circular RNAs (circRNAs) have been emerged as novel regulators in multiple tumorigenesis, including melanoma. CircRNA_0084043 was recently demonstrated to be deregulated in human melanoma cells. Nevertheless, its role and mechanism are largely unrevealed in melanoma. MATERIALS AND METHODS Expression of circ_0084043, miRNA (miR)-429 and tribbles homolog 2 (TRIB2) was detected using reverse transcription-quantitative PCR quantitative PCR (RT-qPCR) and western blotting. Cell proliferation, apoptosis, migration and invasion were measured by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, flow cytometry and transwell assays, respectively. The activation of Wnt/β-catenin pathway was evaluated by western blotting. The target binding among circ_0084043, miR-429 and TRIB2 was confirmed by dual-luciferase reporter assay and RNA immunoprecipitation. In vivo, mice xenograft model was generated to investigate tumor growth. KEY FINDINGS Expression of circ_0084043 and TRIB2 was upregulated in human melanoma tissues and cell lines. Both circ_0084043 knockdown and TRIB2 silencing could decrease cell proliferation, migration and invasion, but facilitate apoptosis in A375 and SK-MEL-28 cells. Furthermore, TRIB2 restoration partially abrogated the tumor-suppressive role of circ_0084043 knockdown in melanoma cells in vitro. Then, we verified that circ_0084043 positively and physically controlled TRIB2 expression through sponging miR-429. Besides, expression of β-catenin, c-Myc and cyclinD1 was inhibited in A375 and SK-MEL-28 cells when circ_0084043 was knocked down, accompanied with increased miR-429 and decreased TRIB2. Notably, circ_0084043 downregulation impeded tumor growth of A375 cells in vivo. SIGNIFICANCE Knockdown of circ_0084043 suppressed the malignant development of melanoma presumably through modulating miR429/TRIB2 axis and inactivating Wnt/β-catenin signaling pathway.

中文翻译：

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敲除circ_0084043可通过miR-429 / tribbles同源2轴和Wnt /β-catenin途径抑制人黑素瘤细胞的发育。

AIMS环形RNA（circRNA）已成为包括黑色素瘤在内的多种肿瘤发生中的新型调节剂。CircRNA_0084043最近被证明在人类黑素瘤细胞中被解除调节。然而，它的作用和机制在黑素瘤中基本上没有揭示。材料与方法使用逆转录定量PCR定量PCR（RT-qPCR）和Western印迹检测circ_0084043，miRNA（miR）-429和tribbles同源物2（TRIB2）的表达。细胞增殖，凋亡，迁移和侵袭分别通过3-（4,5-二甲基噻唑-2-基）-2,5-二苯基四唑溴化物（MTT）测定，流式细胞术和transwell测定来测量。通过蛋白质印迹法评估Wnt /β-catenin途径的激活。circ_0084043之间的目标绑定，miR-429和TRIB2通过双荧光素酶报告基因测定和RNA免疫沉淀得到证实。在体内，产生小鼠异种移植模型以研究肿瘤的生长。主要发现circ_0084043和TRIB2的表达在人黑素瘤组织和细胞系中上调。circ_0084043敲低和TRIB2沉默均可降低细胞增殖，迁移和侵袭，但促进A375和SK-MEL-28细胞凋亡。此外，TRIB2修复部分废除了在体外黑色素瘤细胞中circ_0084043敲低的肿瘤抑制作用。然后，我们验证了circ_0084043通过海绵miR-429积极控制了TRIB2的表达。此外，敲除circ_0084043后，A375和SK-MEL-28细胞中的β-catenin，c-Myc和cyclinD1的表达受到抑制，伴随miR-429升高和TRIB2降低。值得注意的是，circ_0084043下调阻止了A375细胞在体内的肿瘤生长。意义circ_0084043的抑制可能是通过调节miR429 / TRIB2轴和使Wnt /β-catenin信号通路失活而抑制了黑色素瘤的恶性发展。