Yang Yiming, Wang Di, Tao Kaixiong, Wang Guobin
Department of Gastrointestinal Surgery, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430033, People's Republic of China.
Onco Targets Ther. 2022 May 18;15:541-554. doi: 10.2147/OTT.S366605. eCollection 2022.
Colorectal cancer (CRC) is one of the most common carcinomas worldwide with a high mortality rate. Numerous studies suggest that circular RNA (circRNA) plays a crucial role in the progression of various carcinomas, including CRC. The present work focused on exploring the role and underlying molecular mechanism of action of the circRNA circLRCH3 in CRC.
Real-time reverse transcription-quantitative polymerase chain reaction (RT-qPCR) was conducted to detect expression levels of circLRCH3, miR-233, and lipoma preferred partner (LPP). The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay was used to measure the proliferation of CRC cells and the transwell assay was used to evaluate cell migration and invasion capacity. A flow cytometry assay was used to analyze the effect of circLRCH3 on the distribution of the cell cycle and apoptosis of CRC cells. The expression of LPP was analyzed using Western blotting or an RT-qPCR assay. The relationship between miR-223 and circLRCH3, and that between miR-223 and LPP, was predicted and examined using bioinformatics analysis and luciferase reporter gene experiments. A xenograft tumor formation assay was also performed.
We found that the expression level of circLRCH3 was downregulated in CRC cells and negatively correlated with miR-223. The overexpression of circLRCH3 or silencing of miR-223 inhibited the growth, invasion, and migration of CRC cells, but promoted their apoptosis. In contrast, overexpression of miR-223 and depletion of LPP severally abrogated the tumor suppressive roles of circLRCH3 and miR-223 knockdown in CRC cells in vitro. The xenograft experiments in nude mice also proved the antitumor effect of circLRCH3.
These results suggested that the circLRCH3/miR-223/LPP axis likely plays a critical role in CRC.
结直肠癌（CRC）是全球最常见的癌症之一，死亡率很高。大量研究表明，环状RNA（circRNA）在包括CRC在内的各种癌症进展中起关键作用。本研究重点探讨环状RNA circLRCH3在CRC中的作用及其潜在的分子作用机制。
采用实时逆转录定量聚合酶链反应（RT-qPCR）检测circLRCH3、miR-223和脂肪瘤优先伴侣（LPP）的表达水平。采用3-(4,5-二甲基噻唑-2-基)-2,5-二苯基四氮唑溴盐（MTT）法检测CRC细胞的增殖情况，采用Transwell法评估细胞迁移和侵袭能力。采用流式细胞术分析circLRCH3对CRC细胞周期分布和凋亡的影响。采用蛋白质免疫印迹法或RT-qPCR法分析LPP的表达。使用生物信息学分析和荧光素酶报告基因实验预测并检测miR-223与circLRCH3之间以及miR-223与LPP之间的关系。还进行了异种移植肿瘤形成实验。
我们发现，circLRCH3在CRC细胞中的表达水平下调，且与miR-223呈负相关。circLRCH3的过表达或miR-223的沉默抑制了CRC细胞的生长、侵袭和迁移，但促进了它们的凋亡。相反，miR-223的过表达和LPP的缺失分别消除了circLRCH3和miR-223敲低在体外对CRC细胞的肿瘤抑制作用。裸鼠异种移植实验也证明了circLRCH3的抗肿瘤作用。
这些结果表明，circLRCH3/miR-223/LPP轴可能在CRC中起关键作用。
