Li Jingjing, Chen Jia, Wang Shaohua, Li Ping, Zheng Changli, Zhou Xiao, Tao Yongguang, Chen Xiang, Sun Lichun, Wang Aijun, Cao Ke, Tang Shijie, Zhou Jianda
Department of Plastic Surgery of Third Xiangya Hospital, Central South University, Changsha, Hunan, China.
Department of Pathology of Xiangya Hospital and School of Basic Medical Science, Central South University, Changsha, Hunan, China.
J Cell Physiol. 2019 Sep;234(9):15763-15774. doi: 10.1002/jcp.28234. Epub 2019 Feb 5.
There is emerging evidence of bioactive material transport by exosomes in melanoma. However, the functions of exosome content underlying such cancer progression remain largely unknown. We aimed at determining whether exosome secretion contributes to cellular microRNA-494 (miR-494) loss and investigated the roles of miR-494 in melanoma progression. The exosomes from blood serum and cell culture conditioned media were separated by ultracentrifugation. A short hairpin RNA was used to silence rab27a for inhibiting exosome release. To address the functional role of exosomal miR-494, we assessed cell proliferation, migration, invasion capabilities, and cell apoptosis. Finally, subcutaneous xenograft and lung-metastasis models were constructed to determine the effect of exosomal miR-494 in vivo. Based on long noncoding RNA microarray analysis of melanocyte and melanoma-derived exosomes from the Gene Expression Omnibus database, we discovered that miR-494 was enriched in melanoma-derived exosomes. And miR-494 was increased in exosomes secreted from melanoma patients' serum and A375 cells. Rab27a depletion reduced exosome secretion and rescued the abundance of cellular miR-494. Functional studies revealed that knockdown of rab27a and subsequent accumulation of miR-494 significantly suppressed the malignant phenotypes of melanoma cells via inducing cell apoptosis. Nude mice experiments confirmed that tumor growth and metastasis were suppressed by increasing miR-494 accumulation after rab27a depletion. In conclusion, blocking transferred exosome-shuttled miR-494 is a potential therapeutic option for melanoma.
有新证据表明黑色素瘤中外泌体可转运生物活性物质。然而，此类癌症进展过程中外泌体所含物质的功能仍 largely 未知。我们旨在确定外泌体分泌是否导致细胞中微小 RNA-494（miR-494）缺失，并研究 miR-494 在黑色素瘤进展中的作用。通过超速离心从血清和细胞培养条件培养基中分离外泌体。使用短发夹 RNA 使 rab27a 沉默以抑制外泌体释放。为了探讨外泌体 miR-494 的功能作用，我们评估了细胞增殖、迁移、侵袭能力和细胞凋亡。最后，构建皮下异种移植和肺转移模型以确定外泌体 miR-494 在体内的作用。基于对来自基因表达综合数据库的黑素细胞和黑色素瘤来源外泌体的长链非编码 RNA 微阵列分析，我们发现 miR-494 在黑色素瘤来源的外泌体中富集。并且 miR-494 在黑色素瘤患者血清和 A375 细胞分泌的外泌体中增加。Rab27a 的缺失减少了外泌体分泌并挽救了细胞 miR-494 的丰度。功能研究表明，rab27a 的敲低以及随后 miR-494 的积累通过诱导细胞凋亡显著抑制了黑色素瘤细胞的恶性表型。裸鼠实验证实，rab27a 缺失后 miR-494 积累增加可抑制肿瘤生长和转移。总之，阻断外泌体穿梭转运的 miR-494 是黑色素瘤的一种潜在治疗选择。
