RNA-binding protein trinucleotide repeat-containing 6A regulates the formation of circular RNA circ0006916, with important functions in lung cancer cells
RNA-binding protein trinucleotide repeat-containing 6A regulates the formation of circular RNA circ0006916, with important functions in lung cancer cells
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DOI：
10.1093/carcin/bgy061
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发表时间：
2018-08-01
期刊：
影响因子：
4.7
通讯作者：
Jiang, Yiguo
中科院分区：
文献类型：
--
作者：
Dai, Xin;Zhang, Nan;Jiang, Yiguo
环状RNA（circRNA）是与传统线性RNA不同的广泛且多样化的内源RNA，它可能调节真核生物中的基因表达。然而，人类 circRNA 的功能，包括它们在肺癌中的潜在作用，仍然很大程度上未知。我们筛选了 circRNA circ0006916，它在 16HBE-T 细胞（抗苯并芘-反式-7、8-二氢二醇-9、10-环氧化物转化的人支气管上皮细胞）以及 A549 和 H460 细胞系中明显下调。 circ0006916 的沉默，而非其亲本基因 homer 支架蛋白 1 (HOMER1) 的沉默，通过加速细胞周期过程而不是抑制细胞凋亡来促进细胞增殖；相反，circ0006916的过度表达则产生相反的效果。荧光素酶筛选测定表明，circ0006916 与 miR-522-3p 结合，并抑制 pleckstrin 同源结构域和富含亮氨酸的重复蛋白磷酸酶 1 (PHLPP1) 活性。我们还探讨了包含 6A (TNRC6A) 的 RNA 结合蛋白三核苷酸重复序列对 circ0006916 产生的影响。沉默 TNRC6A 后，Circ0006916 表达降低。 RNA 免疫沉淀分析与测序分析相结合显示，TNRC6A 与 circ0006916 形成 circRNA 的外显子周围的内含子区域结合。通过 RNA Pull-down 测定进一步验证了 circ0006916 与 TNRC6A 的关联。然后我们构建了载体并确认TNRC6A与circ0006916的侧翼内含子区域的结合对于circ0006916的产生是必要的。这些结果表明，TNRC6A 调节 circRNA circ0006916 的生物合成，其在细胞生长中具有调节作用。
Circular RNAs (circRNAs) are widespread and diverse endogenous RNAs distinct from traditional linear RNAs, which may regulate gene expression in eukaryotes. However, the function of human circRNAs, including their potential role in lung cancer, remains largely unknown. We screened the circRNA circ0006916, which was evidently down-regulated in 16HBE-T cells (anti-benzopyrene-trans-7, 8-dihydrodiol-9, 10-epoxide-transformed human bronchial epithelial cells), and in A549 and H460 cell lines. Silencing of circ0006916, but not its parental gene homer scaffolding protein 1 (HOMER1), promoted cell proliferation via speeding up the cell cycle process rather than by inhibiting apoptosis; conversely, overexpression of circ0006916 had the opposite effect. Luciferase-screening assay indicated that circ0006916 bound to miR-522-3p and inhibited pleckstrin homology domain and leucine rich repeat protein phosphatase 1 (PHLPP1) activity. We also explored the effect of the RNA-binding protein trinucleotide repeat-containing 6A (TNRC6A) on circ0006916 production. Circ0006916 expression was decreased after silencing TNRC6A. TNRC6A bound to the intron regions around the circRNA-forming exons of circ0006916, as shown by RNA immunoprecipitation assay combined with sequencing analysis. The association of circ0006916 with TNRC6A was further verified by RNA pull-down assays. We then constructed a carrier and confirmed that TNRC6A binding to the flanked intron region of circ0006916 was necessary for generation of circ0006916. These results demonstrate that TNRC6A regulates the biogenesis of the circRNA circ0006916, which has a regulatory role in cell growth.