CircCOL5A1 is involved in proliferation, invasion, and inhibition of ferroptosis of colorectal cancer cells via miR-1287-5p/SLC7A11

Colorectal cancer (CRC) is the leading cause of cancer-related death globally. Circular RNA circCOL5A1 plays an oncogene function in a variety of tumors. However, the function of circCOL5A1 in CRC is still unknown. Here, we aimed to elucidate the function and mechanism of circCOL5A1 in CRC. The correlation between circCOL5A1 and CRC clinicopathological was assessed through chi-square. The relevance between circCOL5A1 and CRC patient survival time was evaluated by Kaplan–Meier analysis. The expressions of circCOL5A1 in CRC were determined via quantitative real-time PCR. The function of circCOL5A1 in CRC was analyzed with Cell Counting Kit-8, EdU assay, Transwell, detection of reactive oxygen species and Fe²⁺ levels, and Western blot analysis. Moreover, the mechanism of circCOL5A1 was determined by dual-luciferase reporter assay, RNA immunoprecipitation, and RNA pull-down. Finally, the role of circCOL5A1 in vivo was elucidated through a mouse xenograft model, hematoxylin–eosin staining, and immunohistochemistry. CircCOL5A1 expression was increased in CRC, and increased circCOL5A1 levels were related to TNM stage, lymph node metastasis, distant metastasis, and tumor differentiation in CRC patients, and CRC patients with high circCOL5A1 levels had a low overall survival rate. For the circCOL5A1 function in CRC, we found that circCOL5A1 knockdown weakened CRC cell proliferation and invasion, and enhanced cell ferroptosis. For the circCOL5A1 mechanism in CRC, we further confirmed that circCOL5A1 bound to miR-1287-5p, miR-1287-5p bound to SLC7A11. SLC7A11 was negatively interrelated to miR-1287-5p and was positively interrelated to circCOL5A1 in CRC tissues. Furthermore, interfering circCOL5A1 decreased SLC7A11 expression, and this trend was abolished through miR-1287-5p cotransfection. Rescue assays further demonstrated that circCOL5A1 knockdown alleviated CRC cell malignant phenotype via miR-1287-5p/SLC7A11. Moreover, interference with circCOL5A1 reduced CRC growth in vivo. CircCOL5A1 functioned as an oncogene in CRC via miR-1287-5p/SLC7A11.