Han Bingbing, Wang Xiaohong, Yin Xia
Department of Gastroenterology, Weifang No.2 People's Hospital, Weifang, Shandong, China.
Department of Health, Weifang No.2 People's Hospital, Weifang, Shandong, China.
Dig Dis Sci. 2022 Feb;67(2):504-515. doi: 10.1007/s10620-021-06859-w. Epub 2021 Feb 25.
Colorectal cancer (CRC) is a common cancer with high metastatic property. Circular RNAs (circRNAs) have important involvement in cancer processes. This study focused on the regulation of circRNA RAD23 homologue B (circRAD23B) in CRC.
The levels of circRAD23B, microRNA-1205 (miR-1205), and tripartite motif-44 (TRIM44) were examined by quantitative real-time polymerase chain reaction (qRT-PCR). Functional analyses were performed by Cell Counting Kit-8 (CCK-8) for cell proliferation, flow cytometry for cell cycle or cell apoptosis, and transwell assay for cell migration and invasion. Western blot was administrated for protein detection. The interaction of targets was analyzed by dual-luciferase reporter and RNA pull-down assays. The in vivo experiment was conducted via xenograft tumor in mice.
We identified that circRAD23B was overexpressed in CRC tissues and cells. CRC cell proliferation, cell cycle progression, and cell metastasis were inhibited, while apoptosis was promoted by downregulating circRAD23B. Target analysis indicated that circRAD23B-targeted miR-1205 and TRIM44 were downstream genes of miR-1205. Moreover, the antitumor response of circRAD23B downregulation and miR-1205 overexpression was, respectively, achieved by increasing miR-1205 and decreasing TRIM44. CircRAD23B could regulate TRIM44 level by sponging miR-1205. In vivo, circRAD23B knockdown also reduced CRC tumorigenesis via the miR-1205/TRIM44 axis.
These results suggested that the inhibition of circRAD23B retarded the progression of CRC via acting on the miR-1205/TRIM44 axis. CircRAD23B might be a novel target in CRC treatment.
结直肠癌（CRC）是一种具有高转移特性的常见癌症。环状RNA（circRNAs）在癌症发生过程中发挥重要作用。本研究聚焦于circRNA RAD23同源物B（circRAD23B）在结直肠癌中的调控作用。
采用定量实时聚合酶链反应（qRT-PCR）检测circRAD23B、微小RNA-1205（miR-1205）和三联基序蛋白44（TRIM44）的水平。通过细胞计数试剂盒-8（CCK-8）检测细胞增殖，流式细胞术检测细胞周期或细胞凋亡，Transwell实验检测细胞迁移和侵袭，进行功能分析。采用蛋白质免疫印迹法检测蛋白质。通过双荧光素酶报告基因和RNA下拉实验分析靶点间的相互作用。通过小鼠异种移植瘤实验进行体内实验。
我们发现circRAD23B在结直肠癌组织和细胞中高表达。下调circRAD23B可抑制结直肠癌细胞增殖、细胞周期进程和细胞转移，同时促进细胞凋亡。靶点分析表明，circRAD23B靶向的miR-1205和TRIM44是miR-1205的下游基因。此外，下调circRAD23B和上调miR-1205分别通过增加miR-1205和降低TRIM44实现抗肿瘤反应。circRAD23B可通过海绵吸附miR-1205来调节TRIM44水平。在体内，敲低circRAD23B也通过miR-1205/TRIM44轴降低了结直肠癌的肿瘤发生。
这些结果表明，抑制circRAD23B通过作用于miR-1205/TRIM44轴延缓了结直肠癌的进展。circRAD23B可能是结直肠癌治疗的新靶点。
