Department of Gastrointestinal Surgery, Second Affiliated Hospital of Chongqing Medical University, 288 Tianwen Dadao Road, Nanan District, Chongqing, 401336, China.
Shanghai Engineering Research Center of Pharmaceutical Translation, Shanghai, 200231, China.
BMC Genomics. 2021 Oct 27;22(1):768. doi: 10.1186/s12864-021-07880-z.
Colon cancer (CC) is one of the most common cancers whose progression is regulated by a number of factors, including circular RNAs (circRNAs). Nonetheless, circ_0038718 is a novel circRNA, and its regulatory mechanism in CC remains unclear.
Real-time quantitative PCR (qRT-PCR) was performed to detect the expression of circ_0038718, miR-195-5p and Axin2. Western blot was conducted to determine the protein expression of Axin2 and the key proteins on Wnt/β-catenin signaling pathway. Oligo (dT) primers and RNase R were employed to identify the circular features of circ_0038718, and the location of circ_0038718 in cells was detected via nucleocytoplasmic separation. Dual-luciferase reporter assay and RNA binding protein immunoprecipitation experiment were carried out to investigate the molecular mechanism of circ_0038718/miR-195-5p/Axin2. Additionally, MTT assay was conducted to assess cell proliferation; Transwell assay was performed to evaluate cell migration and invasion, respectively. The effect of circ_0038718 on CC tumor growth was tested through tumor formation in nude mice.
circ_0038718 was highly expressed in CC and could sponge miR-195-5p in cytoplasm. Silencing circ_0038718 suppressed the proliferative, migratory and invasive abilities of CC cells, while the promoting effect of high circ_0038718 expression on CC cells was reversed upon miR-195-5p over-expression. Axin2 was a downstream target of miR-195-5p and could regulate the Wnt/β-catenin signaling pathway. Axin2 expression was modulated by circ_0038718/miR-195-5p. Knockdown of Axin2 could also attenuate the promoting effect of high circ_0038718 expression on CC cell malignant progression, thus inhibiting tumor growth.
circ_0038718 is able to facilitate CC cell malignant progression via the miR-195-5p/Axin2 axis, which will provide a new idea for finding a novel targeted treatment of CC.
结肠癌（CC）是最常见的癌症之一，其进展受多种因素调控，包括环状 RNA（circRNA）。然而，circ_0038718 是一种新的 circRNA，其在 CC 中的调控机制尚不清楚。
采用实时定量 PCR（qRT-PCR）检测 circ_0038718、miR-195-5p 和 Axin2 的表达。采用 Western blot 检测 Axin2 及 Wnt/β-catenin 信号通路关键蛋白的表达。采用寡聚（dT）引物和 RNase R 鉴定 circ_0038718 的环状特征，并通过核质分离检测 circ_0038718 在细胞中的位置。采用双荧光素酶报告基因检测和 RNA 结合蛋白免疫沉淀实验研究 circ_0038718/miR-195-5p/Axin2 的分子机制。此外，采用 MTT 法评估细胞增殖，Transwell 法分别评估细胞迁移和侵袭。通过裸鼠成瘤实验检测 circ_0038718 对 CC 肿瘤生长的影响。
circ_0038718 在 CC 中高表达，可在细胞质中海绵吸附 miR-195-5p。沉默 circ_0038718 抑制 CC 细胞的增殖、迁移和侵袭能力，而过表达 miR-195-5p 可逆转高 circ_0038718 表达对 CC 细胞的促进作用。Axin2 是 miR-195-5p 的下游靶基因，可调节 Wnt/β-catenin 信号通路。circ_0038718/miR-195-5p 可调节 Axin2 的表达。敲低 Axin2 也可减弱高 circ_0038718 表达对 CC 细胞恶性进展的促进作用，从而抑制肿瘤生长。
circ_0038718 可通过 miR-195-5p/Axin2 轴促进 CC 细胞恶性进展，为寻找 CC 的新型靶向治疗提供新的思路。
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