Department of General Surgery, Peking Union Medical College Hospital, Peking Union Medical College and Chinese Academy of Medical Sciences, Beijing 100730, China.
Beijing GenePlus Clinical Laboratory Co., Ltd., Beijing 102206, China.
Carcinogenesis. 2023 Jun 24;44(4):317-327. doi: 10.1093/carcin/bgad014.
Colorectal cancer (CRC) is the second leading cause of cancer-induced death in the world. Cancer-associated fibroblasts (CAFs) released exosomes that contributed to cancer progression. This research was carried out to study the influence of CRC-associated fibroblasts-derived exosomes on the phenotype of CRC cells and the underlying mechanism. CAFs-derived exosomes (CAFs-exo) and normal fibroblasts (NFs)-derived exosomes (NFs-exo) were recognized by transmission electronic microscopy, nanoparticle tracking analysis and western blot analysis. Cell counting kit-8, flow cytometry analysis, colony formation assay, Transwell, qRT-PCR, immunofluorescence, immunohistochemistry staining and xenografts model were carried out to proceed with function studies in vitro and in vivo. The results showed that CAFs-exo induced cell proliferation, migration and invasion, while NFs-exo did not influence the tumor biological properties of CRC cells. Using qRT-PCR, miR-345-5p was observed to be a notably up-regulated miRNA in CAFs-exo compared to NFs-exo. CAFs-exo could mediate the transfer of miR-345-5p to CRC cells, and downregulation of miR-345-5p in CAFs notably reversed the pro-tumoral effect of CAFs-exo on CRC cells. Based on online prediction database, CDKN1A was proved as a direct downstream target of miR-345-5p in CRC cells, which was lowly expressed and negatively associated with miR-345-5p in CRC tumors. Furthermore, miR-345-5p upregulation-mediated tumor biological behaviors were abrogated by exogenous CDKN1A. In CRC cells-beared tumor xenograft, CAFs-exo administration promoted tumor growth and decreased CDKN1A expression, whereas miR-345-5p inhibition reversed these effects. The present study revealed that by interacting with CDKN1A, CAF-derived exosomal miR-345-5p promotes CRC progression and metastasis.
结直肠癌（CRC）是全球第二大癌症相关死亡原因。癌相关成纤维细胞（CAFs）释放的外泌体促进了癌症的进展。本研究旨在研究 CRC 相关成纤维细胞衍生的外泌体对 CRC 细胞表型的影响及其潜在机制。通过透射电子显微镜、纳米颗粒跟踪分析和 Western blot 分析鉴定 CAFs 衍生的外泌体（CAFs-exo）和正常成纤维细胞（NFs）衍生的外泌体（NFs-exo）。通过细胞计数试剂盒-8、流式细胞术分析、集落形成实验、Transwell、qRT-PCR、免疫荧光、免疫组化染色和异种移植模型进行体外和体内功能研究。结果表明，CAFs-exo 诱导 CRC 细胞增殖、迁移和侵袭，而 NFs-exo 对 CRC 细胞的肿瘤生物学特性没有影响。通过 qRT-PCR，发现与 NFs-exo 相比，CAFs-exo 中 miR-345-5p 显著上调。CAFs-exo 可以介导 miR-345-5p 向 CRC 细胞的转移，下调 CAFs 中的 miR-345-5p 显著逆转了 CAFs-exo 对 CRC 细胞的促肿瘤作用。基于在线预测数据库，CDKN1A 被证明是 CRC 细胞中 miR-345-5p 的直接下游靶标，在 CRC 肿瘤中低表达且与 miR-345-5p 呈负相关。此外，miR-345-5p 上调介导的肿瘤生物学行为被外源性 CDKN1A 阻断。在 CRC 细胞荷瘤异种移植中，CAFs-exo 给药促进肿瘤生长并降低 CDKN1A 表达，而 miR-345-5p 抑制则逆转了这些效应。本研究揭示了 CAF 衍生的外泌体 miR-345-5p 通过与 CDKN1A 相互作用促进 CRC 的进展和转移。
