Universidad Autónoma de Nuevo León, College of Biological Sciences, Department of Cellular Biology and Genetics, San Nicolás de los Garza, Nuevo León, Mexico.
Department of Experimental Therapeutics, The University of Texas MD Anderson Cancer Center, Houston, TX, USA.
Dis Markers. 2019 Feb 12;2019:6852917. doi: 10.1155/2019/6852917. eCollection 2019.
miR-145, miR-155, and miR-382 have been proposed as noninvasive biomarkers to distinguish breast cancer patients from healthy individuals. However, it is unknown if these three miRNAs are secreted by exosomes. Thus, we hypothesized that miR-145, miR-155, and miR-382 in breast cancer patients are present in exosomes. We isolated exosomes from serum of breast cancer patients and healthy donors, then we characterized them according to their shape, size, and exosome markers by scanning electron microscopy, atomic force microscopy, nanoparticle tracking analysis (NTA), and Western blot and determined the exosome concentration in all samples by NTA. Later, exosomal small RNA extraction was done to determine the expression levels of miR-145, miR-155, and miR-382 by qRT-PCR. We observed a round shape of exosomes with a mean size of 119.84 nm in breast cancer patients and 115.4 nm in healthy donors. All exosomes present the proteins CD63, Alix, Tsg, CD9, and CD81 commonly used as markers. Moreover, we found a significantly high concentration of exosomes in breast cancer patients with stages I, III, and IV compared to healthy donors. We detected miR-145, miR-155, and miR-382 in the exosomes isolated from serum of breast cancer patients and healthy donors. Our results show that the exosomes isolated from the serum of breast cancer patients and healthy donors contains miR-145, miR-155, and miR-382 but not in a selective manner in breast cancer patients. Moreover, our data support the association between exosome concentration and the presence of breast cancer, opening the possibility to study how miRNAs packaged into exosomes play a role in BC progression.
miR-145、miR-155 和 miR-382 已被提议作为区分乳腺癌患者与健康个体的非侵入性生物标志物。然而，目前尚不清楚这三种 miRNA 是否通过外泌体分泌。因此，我们假设乳腺癌患者的 miR-145、miR-155 和 miR-382 存在于外泌体中。我们从乳腺癌患者和健康供体的血清中分离出外泌体，然后通过扫描电子显微镜、原子力显微镜、纳米颗粒跟踪分析（NTA）和 Western blot 根据它们的形状、大小和外泌体标记物对其进行特征描述，并通过 NTA 确定所有样品中外泌体的浓度。随后，进行外泌体小 RNA 提取，通过 qRT-PCR 确定 miR-145、miR-155 和 miR-382 的表达水平。我们观察到乳腺癌患者中外泌体呈圆形，平均大小为 119.84nm，健康供体中外泌体为 115.4nm。所有外泌体均表达 CD63、Alix、Tsg、CD9 和 CD81 等常用标记物。此外，我们发现与健康供体相比，I、III 和 IV 期乳腺癌患者中外泌体的浓度显著更高。我们在从乳腺癌患者和健康供体血清中分离的外泌体中检测到了 miR-145、miR-155 和 miR-382。我们的结果表明，从乳腺癌患者和健康供体血清中分离的外泌体中含有 miR-145、miR-155 和 miR-382，但在乳腺癌患者中并非以选择性方式存在。此外，我们的数据支持外泌体浓度与乳腺癌存在之间的关联，为研究包裹在 exosomes 中的 miRNAs 如何在 BC 进展中发挥作用开辟了可能性。
