Exosomal miR-221/222 enhances tamoxifen resistance in recipient ER-positive breast cancer cells
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Recent studies have demonstrated that specific miRNAs, such as miR-221/222, may be responsible for tamoxifen resistance in breast cancer. Secreted miRNAs enclosed in exosomes can act as intercellular bio-messengers. Our objective is to investigate the role of secreted miR-221/222 in tamoxifen resistance of ER-positive breast cancer cells. Transmission electron microscopy analysis and nanoparticle tracking analysis were performed to determine the exosomes difference between MCF-7TamR (tamoxifen resistant) and MCF-7wt (tamoxifen sensitive) cells. PKH67 fluorescent labeling assay was used to detect exosomes derived from MCF-7TamR cells entering into MCF-7wt cells. The potential function of exosomes on tamoxifen resistance transmission was analyzed with cell viability, apoptosis ,and colony formation. MiRNA microarrays and qPCR were used to detect and compare the miRNAs expression levels in the two cells and exosomes. As the targets of miR-221/222, p27 and ERα were analyzed with western blot and qPCR. Compared with the MCF-7wt exosomes, there were significant differences in the concentration and size distribution of MCF-7TamR exosomes. MCF-7wt cells had an increased amount of exosomal RNA and proteins compared with MCF-7TamR cells. MCF-7TamR exosomes could enter into MCF-7wt cells, and then released miR-221/222. And the elevated miR-221/222 effectively reduced the target genes expression of P27 and ERα, which enhanced tamoxifen resistance in recipient cells. Our results are the first to show that secreted miR-221/222 serves as signaling molecules to mediate communication of tamoxifen resistance.
KeywordsExosomal miR-221/222 Tamoxifen resistance Estrogen receptor Breast cancer
Estrogen receptor α
We thank Shuai Zhang for his excellent technical support of nanoparticle tracking analysis. This study was supported by National Natural Science Foundation of China (Nos. 81202091, 81372390 and 81102006).
Conflict of interest
The authors declare no conflict of interest.
- 2.Katzenellenbogen BS, Miller MA, Mullick A, Sheen YY (1985) Antiestrogen action in breast cancer cells: modulation of proliferation and protein synthesis, and interaction with estrogen receptors and additional antiestrogen binding sites. Breast Cancer Res Treat 5(3):231–243PubMedCrossRefGoogle Scholar
- 12.Lawrie CH, Gal S, Dunlop HM, Pushkaran B, Liggins AP, Pulford K, Banham AH, Pezzella F, Boultwood J, Wainscoat JS et al (2008) Detection of elevated levels of tumour-associated microRNAs in serum of patients with diffuse large B-cell lymphoma. Br J Haematol 141(5):672–675PubMedCrossRefGoogle Scholar
- 20.Peinado H, Aleckovic M, Lavotshkin S, Matei I, Costa-Silva B, Moreno-Bueno G, Hergueta-Redondo M, Williams C, Garcia-Santos G, Ghajar C et al (2012) Melanoma exosomes educate bone marrow progenitor cells toward a pro-metastatic phenotype through MET. Nat Med 18(6):883–891PubMedCentralPubMedCrossRefGoogle Scholar
- 22.van Balkom BW, de Jong OG, Smits M, Brummelman J, den Ouden K, de Bree PM, van Eijndhoven MA, Pegtel DM, Stoorvogel W, Wurdinger T et al (2013) Endothelial cells require miR-214 to secrete exosomes that suppress senescence and induce angiogenesis in human and mouse endothelial cells. Blood 121(19):3997–4006, S3991–3915Google Scholar
- 31.Takeshita N, Hoshino I, Mori M, Akutsu Y, Hanari N, Yoneyama Y, Ikeda N, Isozaki Y, Maruyama T, Akanuma N et al (2013) Serum microRNA expression profile: miR-1246 as a novel diagnostic and prognostic biomarker for oesophageal squamous cell carcinoma. Br J Cancer 108(3):644–652PubMedCentralPubMedCrossRefGoogle Scholar
- 32.Banigan MG, Kao PF, Kozubek JA, Winslow AR, Medina J, Costa J, Schmitt A, Schneider A, Cabral H, Cagsal-Getkin O et al (2013) Differential expression of exosomal microRNAs in prefrontal cortices of schizophrenia and bipolar disorder patients. PLoS One 8(1):e48814PubMedCentralPubMedCrossRefGoogle Scholar
- 36.Ostrowski M, Carmo NB, Krumeich S, Fanget I, Raposo G, Savina A, Moita CF, Schauer K, Hume AN, Freitas RP et al (2010) Rab27a and Rab27b control different steps of the exosome secretion pathway. Nat Cell Biol 12(1):19–30; sup 11–13Google Scholar
- 37.van der Pol E, Coumans FA, Grootemaat AE, Gardiner C, Sargent IL, Harrison P, Sturk A, van Leeuwen TG, Nieuwland R (2014) Particle size distribution of exosomes and microvesicles by transmission electron microscopy, flow cytometry, nanoparticle tracking analysis, and resistive pulse sensing. J Thromb Haemost. doi: 10.1111/jth.12602 PubMedGoogle Scholar