Song Mo, Liu Jipan
Department of Anorectal Surgery, Hengshui People's Hospital, Hengshui, China.
Histol Histopathol. 2023 Jan;38(1):53-64. doi: 10.14670/HH-18-494. Epub 2022 Jul 12.
Circular RNAs (circRNAs) have been shown to exert vital functions in colorectal cancer (CRC) development. However, the role of circ_0067717 in CRC progression remains to be elucidated.
The expression of circ_0067717, microRNA (miR)-497-5p and solute carrier family 7 member 5 (SLC7A5) was analyzed by quantitative real-time PCR. Cell proliferation, apoptosis and invasion were determined by cell counting kit 8 assay, EdU assay, flow cytometry and transwell assay. Protein expression was examined using western blot analysis. Glutamine metabolism was assessed by measuring glutamine consumption, α-ketoglutarate production and glutamate production. The interaction between miR-497-5p and circ_0067717 or SLC7A5 was identified by dual-luciferase reporter assay. Xenograft tumor models were constructed to confirm the role of circ_0067717 in CRC tumorigenesis in vivo.
Our data revealed that circ_0067717 was upregulated in CRC tissues and cells, and its knockdown restrained CRC cell proliferation, invasion, glutamine metabolism, and promoted apoptosis. MiR-497-5p was lowly expressed in CRC and it could be sponged by circ_0067717. MiR-497-5p inhibitor eliminated the regulation of circ_0067717 knockdown on CRC cell function. SLC7A5 was targeted by miR-497-5p and was positively regulated by circ_0067717. MiR-497-5p overexpression suppressed CRC cell growth, invasion and glutamine metabolism, and SLC7A5 was able to revoke this effect. Animal experiments showed that interference of circ_0067717 reduced CRC tumor growth.
Our research pointed out that circ_0067717 facilitated CRC development depending on the regulation of the miR-497-5p/SLC7A5 axis, providing a novel insight into CRC treatment.
环状RNA（circRNAs）已被证明在结直肠癌（CRC）发展中发挥重要作用。然而，circ_0067717在CRC进展中的作用仍有待阐明。
通过定量实时PCR分析circ_0067717、微小RNA（miR）-497-5p和溶质载体家族7成员5（SLC7A5）的表达。通过细胞计数试剂盒8检测、EdU检测、流式细胞术和Transwell检测确定细胞增殖、凋亡和侵袭情况。使用蛋白质印迹分析检测蛋白质表达。通过测量谷氨酰胺消耗、α-酮戊二酸生成和谷氨酸生成评估谷氨酰胺代谢。通过双荧光素酶报告基因检测确定miR-497-5p与circ_0067717或SLC7A5之间的相互作用。构建异种移植肿瘤模型以证实circ_0067717在体内CRC肿瘤发生中的作用。
我们的数据显示circ_0067717在CRC组织和细胞中上调，其敲低抑制CRC细胞增殖、侵袭、谷氨酰胺代谢并促进凋亡。miR-497-5p在CRC中低表达，且可被circ_0067717吸附。miR-497-5p抑制剂消除了circ_0067717敲低对CRC细胞功能的调节。SLC7A5是miR-497-5p的靶标，并受circ_0067717正向调控。miR-497-5p过表达抑制CRC细胞生长、侵袭和谷氨酰胺代谢，而SLC7A5能够消除这种作用。动物实验表明，干扰circ_0067717可减少CRC肿瘤生长。
我们的研究指出，circ_0067717通过调节miR-497-5p/SLC7A5轴促进CRC发展，为CRC治疗提供了新的见解。
