Department of Proctology, Jining Hospital of Traditional Chinese Medicine, Jining, China.
Department of Gastroenterology, Yidu Central Hospital of Weifang, Weifang, China.
Eur J Clin Invest. 2021 Jul;51(7):e13541. doi: 10.1111/eci.13541. Epub 2021 Apr 2.
Ferroptosis is an iron-dependent and oxidative cell death form. Recent studies suggested that circular RNAs (circRNAs) regulated ferroptosis in tumour cells. Circ_0007142 was identified as a carcinogenic molecule in colorectal cancer (CRC), but its function on ferroptosis in CRC remains unknown.
Circ_0007142, microRNA-874-3p (miR-874-3p) and glycerophosphodiester phosphodiesterase domain containing 5 (GDPD5) levels were assayed using the quantitative real-time polymerase chain reaction (qRT-PCR). Cell survival and proliferation were measured by Cell Counting Kit-8 (CCK-8) assay. Protein detection was performed by Western blot. Cell apoptosis was analysed by flow cytometry. Ferroptosis was assessed by iron accumulation and oxidative stress. Target binding was evaluated by dual-luciferase reporter assay. In vivo research was conducted by tumour xenograft in mice.
Circ_0007142 was overexpressed in CRC. After expression inhibition of circ_0007142, proliferation was reduced, while apoptosis and ferroptosis were facilitated in CRC cells. Mechanically, circ_0007142 was found as a miR-874-3p sponge and miR-874-3p inhibitor eliminated the regulation of si-circ_0007142 in CRC cells. MiR-874-3p targeted GDPD5 and upregulation of GDPD5 reversed the miR-874-3p-triggered tumour inhibition and ferroptosis promotion in CRC cells. Moreover, GDPD5 was regulated by the circ_0007142/miR-874-3p axis. Circ_0007142 also affected CRC tumorigenesis in vivo through the regulation of miR-874-3p and GDPD5.
All these findings proved that circ_0007142/miR-874-3p/GDPD5 axis regulated tumorigenesis and ferroptosis of CRC cells. Circ_0007142 might be an available marker for ferroptosis in CRC therapy.
铁死亡是一种依赖铁和氧化的细胞死亡形式。最近的研究表明，环状 RNA（circRNA）调节肿瘤细胞中的铁死亡。Circ_0007142被确定为结直肠癌（CRC）中的致癌分子，但它在 CRC 中铁死亡的功能尚不清楚。
使用实时定量聚合酶链反应（qRT-PCR）测定 Circ_0007142、microRNA-874-3p（miR-874-3p）和甘油磷酸二酯磷酸二酯酶结构域包含 5（GDPD5）的水平。通过细胞计数试剂盒-8（CCK-8）测定细胞存活和增殖。通过 Western blot 进行蛋白检测。通过流式细胞术分析细胞凋亡。通过铁积累和氧化应激评估铁死亡。通过双荧光素酶报告基因测定评估靶标结合。通过在小鼠中的肿瘤异种移植进行体内研究。
Circ_0007142 在 CRC 中过度表达。抑制 Circ_0007142 的表达后，CRC 细胞的增殖减少，而凋亡和铁死亡增加。机制上，Circ_0007142 被发现为 miR-874-3p 的海绵，miR-874-3p 抑制剂消除了 si-circ_0007142 在 CRC 细胞中的调节作用。miR-874-3p 靶向 GDPD5，上调 GDPD5 逆转了 miR-874-3p 触发的 CRC 细胞肿瘤抑制和铁死亡促进作用。此外，GDPD5 受 circ_0007142/miR-874-3p 轴的调节。Circ_0007142 还通过调节 miR-874-3p 和 GDPD5 影响体内 CRC 肿瘤发生。
这些发现证明了 circ_0007142/miR-874-3p/GDPD5 轴调节 CRC 细胞的肿瘤发生和铁死亡。Circ_0007142 可能是 CRC 治疗中铁死亡的有效标志物。
