Han Yue, Zhou Zhe, Li Rudong, Wang Hong
The Second Department of Gastrointestinal Surgery, Shandong Provincial Third Hospital, Jinan City, China.
J Biochem Mol Toxicol. 2025 Apr;39(4):e70225. doi: 10.1002/jbt.70225.
Tumor-associated macrophages (TAM) have been shown to regulate colon cancer (CC) progression. However, it is not clear whether tumor-derived exosomal circular RNA (circRNA) regulates TAM to influence CC progression. The expression levels of circ_0020095, M1 macrophage markers, M2 macrophage markers, and interleukin-1 receptor-associated kinase 1 (IRAK1) were determined by qRT-PCR. Cell proliferation, migration and invasion were examined by EdU assay, wound healing assay and transwell assay. Exosomes derived from CC cells were used to treat M0 macrophages. M1 macrophage surface marker CD86 was detected by flow cytometry, and protein expression was examined by western blot. Then, the medium of exosome-treated M0 macrophages was used to culture CC cells to determine CC cell functions. RNA pull-down assay, RIP assay and dual-luciferase reporter assay were performed to validate interaction. Circ_0020095 had elevated expression in CC tissues and cells, and its knockdown repressed CC cell proliferation and metastasis. M0 macrophages could take by CC cell-derived exosomes to regulate circ_0020095 expression. Exosomal circ_0020095 restrained M1 macrophage polarization and increased M2 macrophage polarization to enhance CC cell progression. Besides, IRAK1 silencing could promote CC cell proliferation and metastasis by inhibiting M1 macrophage polarization, and its overexpression also abolished the effect of exosomal circ_0020095. Mechanistically, circ_0020095 could competitively bind to IGF2BP1 and then reduced the binding ability of IGF2BP1 and IRAK1 3'UTR. Tumor-derived exosomal circ_0020095 promoted CC cell progression via inhibiting M1 macrophage polarization through IGF2BP1/IRAK1 axis.
肿瘤相关巨噬细胞（TAM）已被证明可调节结肠癌（CC）的进展。然而，尚不清楚肿瘤来源的外泌体环状RNA（circRNA）是否通过调节TAM来影响CC的进展。通过qRT-PCR检测circ_0020095、M1巨噬细胞标志物、M2巨噬细胞标志物和白细胞介素-1受体相关激酶1（IRAK1）的表达水平。通过EdU检测、伤口愈合检测和Transwell检测来检测细胞增殖、迁移和侵袭。用CC细胞来源的外泌体处理M0巨噬细胞。通过流式细胞术检测M1巨噬细胞表面标志物CD86，并通过蛋白质印迹法检测蛋白质表达。然后，用经外泌体处理的M0巨噬细胞的培养基培养CC细胞，以确定CC细胞的功能。进行RNA下拉检测、RIP检测和双荧光素酶报告基因检测以验证相互作用。Circ_0020095在CC组织和细胞中表达升高，其敲低可抑制CC细胞增殖和转移。M0巨噬细胞可摄取CC细胞来源的外泌体以调节circ_0020095的表达。外泌体circ_0020095抑制M1巨噬细胞极化并增加M2巨噬细胞极化，从而促进CC细胞进展。此外，IRAK1沉默可通过抑制M1巨噬细胞极化促进CC细胞增殖和转移，其过表达也消除了外泌体circ_0020095的作用。机制上，circ_0020095可竞争性结合IGF2BP1，进而降低IGF2BP1与IRAK1 3'UTR的结合能力。肿瘤来源的外泌体circ_0020095通过IGF2BP1/IRAK1轴抑制M1巨噬细胞极化，从而促进CC细胞进展。
