Exosomal miR-500a-5p derived from cancer-associated fibroblasts promotes breast cancer cell proliferation and metastasis through targeting USP28.
Exosomal miR-500a-5p derived from cancer-associated fibroblasts promotes breast cancer cell proliferation and metastasis through targeting USP28.
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源自癌症相关成纤维细胞的外泌体 miR-500a-5p 通过靶向 USP28 促进乳腺癌细胞增殖和转移
作者：
Chen B;Sang Y;Song X;Zhang D;Wang L;Zhao W;Liang Y;Zhang N;Yang Q
肿瘤微环境有助于肿瘤的进展和转移。癌症相关成纤维细胞（CAFs）形成肿瘤微环境的主要细胞成分。在这项研究中，我们进一步探讨了CAFs促进肿瘤作用的机制。方法：从乳腺癌及邻近正常乳腺组织中分离患者源性CAFs和正常成纤维细胞（NFs）。通过超离心分离外泌体，并使用下一代测序技术筛选caf衍生的外泌体microrna。采用实时定量聚合酶链反应（qRT-PCR）和原位杂交技术检测MiR-500a-5p的表达；MTT法和三维培养法检测肿瘤细胞增殖，Transwell法检测肿瘤转移。体内实验在裸鼠皮下异种移植模型中进行。结果：我们证实了caf来源的外泌体显著促进乳腺癌细胞的增殖和转移。MiR-500a-5p在用ca来源的外泌体处理的MDA-MB-231和MCF7细胞中高表达。miR-500a-5p的上调也在caf和caf衍生的外泌体中得到证实。MiR-500a-5p从CAFs转移到癌细胞中，随后通过与泛素特异性肽酶28 （USP28）结合促进增殖和转移。结论：本研究表明，CAFs通过外泌体miR-500a-5p促进乳腺癌的进展和转移，并表明抑制CAFs来源的miR-500a-5p是治疗乳腺癌的另一种方式。
The tumor microenvironment contributes to tumor progression and metastasis. Cancer-associated fibroblasts (CAFs) form a major cellular component of the tumor microenvironment. In this study, we further explored the mechanisms underlying the tumor-promoting roles of CAFs. Methods: Patient-derived CAFs and normal fibroblasts (NFs) were isolated from breast carcinomas and adjacent normal breast tissue. Exosomes were isolated by ultracentrifugation and CAF-derived exosomal microRNAs were screened using next-generation sequencing technology. MiR-500a-5p expression was assessed by quantitative real-time polymerase chain reaction (qRT-PCR) and in situ hybridization; Tumor cell proliferation was determined by MTT assays and three-dimensioned (3D) cultures, and tumor metastasis was determined by Transwell assays in vitro. In vivo assays were performed in a nude mouse subcutaneous xenograft model. Results: We confirmed that CAF-derived exosomes significantly promoted the proliferation and metastasis of breast cancer cells. MiR-500a-5p was highly expressed in MDA-MB-231 and MCF7 cells treated with CAF-derived exosomes. The upregulation of miR-500a-5p was also confirmed in CAFs and CAF-derived exosomes. MiR-500a-5p was transferred from CAFs to the cancer cells, and subsequently promoted proliferation and metastasis by binding to ubiquitin-specific peptidase 28 (USP28). Conclusions: The present study demonstrates that CAFs promote breast cancer progression and metastasis via exosomal miR-500a-5p and indicate that inhibiting CAF-derived miR-500a-5p is an alternative modality for the treatment of breast cancer.