Colorectal cancer (CRC) is one of the main cause of cancer-related deaths. It's reported that bone marrow mesenchymal stem cells (BMSCs) affects tumor development through secreting exosomes. This study aims to investigate the function of BMSCs-derived exosome miR-4461 in CRC. The results of qRT-PCR showed that miR-4461 expression in DLD1, HCT116 and SW480 CRC cells and CRC tissues was lower than that in FHC cells and normal tissues, respectively. And COPB2 mRNA expression was negatively correlated with miR-4461. Western blot was used to detect COPB2 protein expression. Dual-luciferase reporter assay results revealed that miR-4461 targeted COPB2. Transwell assay and CCK-8 assay demonstrated that COPB2 knockdown inhibited HCT116 and SW480 cells proliferation, migration and invasion abilities. Furthermore, BMSCs-derived exosome miR-4461 downregulated COPB2 expression and inhibited HCT116 and SW480 cells migration and invasion. The findings demonstrated that miR-4461 could be a potential target for the diagnosis and treatment of colorectal cancer.

中文翻译：

---

源自骨髓间充质干细胞外来体的MicroRNA-4461通过下调结直肠癌中COPB2的表达来抑制肿瘤发生。

大肠癌（CRC）是与癌症相关的死亡的主要原因之一。据报道，骨髓间充质干细胞（BMSCs）通过分泌外来体影响肿瘤的发展。这项研究旨在调查BMSCs衍生的外泌体miR-4461在CRC中的功能。qRT-PCR结果表明，miR-4461在DLD1，HCT116和SW480 CRC细胞和CRC组织中的表达分别低于FHC细胞和正常组织。COPB2 mRNA的表达与miR-4461呈负相关。免疫印迹用于检测COPB2蛋白表达。双重荧光素酶报告基因测定结果表明，miR-4461靶向COPB2。Transwell分析和CCK-8分析证明COPB2抑制可抑制HCT116和SW480细胞的增殖，迁移和侵袭能力。此外，BMSCs衍生的外泌体miR-4461下调COPB2表达并抑制HCT116和SW480细胞迁移和侵袭。研究结果表明，miR-4461可能是诊断和治疗大肠癌的潜在靶标。