Circular RNA 0029803 (circ_0029803) was found to be upregulated in colorectal cancer (CRC) tissues, but its function and underlying molecular mechanism are not studied in CRC. The expression levels of circ_0029803, microRNA-216b-5p (miR-216b-5p), and ski-oncogene-like (SKIL) were measured by quantitative real-time polymerase chain reaction (qRT-PCR). RNase R treatment was used to affirm the existence of circ_0029803. Cell proliferation, apoptosis, migration, and invasion were assessed by colony formation, flow cytometry, and Transwell assays, respectively. A glucose and lactate assay kit was used to detect glucose consumption and lactate production. Western blot was applied to analyze the levels of all proteins. Dual-luciferase reporter assay was performed to assess the relationship between miR-216b-5p and circ_0029803 or SKIL. Tumor xenograft models were established to elucidate the effect of circ_0029803 in vivo. Circ_0029803 expression was enhanced in CRC tissues and cells, and the 5-year overall survival rate of patients with high circ_0029803 expression was substantially reduced. Circ_0029803 depletion retarded proliferation, migration, invasion, EMT and glycolysis of CRC cells in vitro as well as the tumor growth in vivo. Mechanically, circ_0029803 could serve as miR-216b-5p sponge to regulate its expression, and miR-216b-5p knockdown reversed the inhibition of si-circ_0029803 on the malignant behaviors of CRC cells. Additionally, as the target mRNA of miR-216b-5p, SKIL could counteract the inhibitory effect of miR-216b-5p on the development of CRC cells. Importantly, silencing circ_0029803 reduced SKIL expression via sponging miR-216b-5p. Circ_0029803 knockdown hindered proliferation, migration, invasion, EMT, and glycolysis and promoted apoptosis in CRC cells by modulating the miR-216b-5p/SKIL axis.

中文翻译：

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Circ_0029803 作为 miR-216b-5p 的海绵通过调节 SKIL 表达促进结直肠癌的进展

环状 RNA 0029803 (circ_0029803) 在结直肠癌 (CRC) 组织中被发现上调，但其功能和潜在的分子机制在 CRC 中尚未研究。通过定量实时聚合酶链反应 (qRT-PCR) 测量 circ_0029803、microRNA-216b-5p (miR-216b-5p) 和ski-oncogene-like (SKIL) 的表达水平。RNase R 处理用于确认 circ_0029803 的存在。细胞增殖、凋亡、迁移和侵袭分别通过集落形成、流式细胞术和 Transwell 测定进行评估。葡萄糖和乳酸测定试剂盒用于检测葡萄糖消耗和乳酸产生。应用蛋白质印迹分析所有蛋白质的水平。进行双荧光素酶报告基因测定以评估 miR-216b-5p 与 circ_0029803 或 SKIL 之间的关系。建立肿瘤异种移植模型以阐明circ_0029803在体内的作用。CRC组织和细胞中Circ_0029803表达增强，circ_0029803高表达患者的5年总生存率显着降低。Circ_0029803 耗竭延缓了体外 CRC 细胞的增殖、迁移、侵袭、EMT 和糖酵解以及体内肿瘤的生长。机制上，circ_0029803可以作为miR-216b-5p海绵调节其表达，miR-216b-5p敲低逆转了si-circ_0029803对CRC细胞恶性行为的抑制作用。此外，作为 miR-216b-5p 的靶 mRNA，SKIL 可以抵消 miR-216b-5p 对 CRC 细胞发育的抑制作用。重要的是，沉默 circ_0029803 通过海绵化 miR-216b-5p 降低了 SKIL 的表达。