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MicroRNAs are reported as promising biomarkers for the diagnosis and treatment of breast cancer. miR-1260b is identified as a tumor-associated noncoding microRNA in other cancers, although the role of miR-1260b and its clinical relevance in breast cancer remain unclear. In this study, miR-1260b as a potential prognostic biomarker was observed by univariate and multivariate Cox regression analyses in 102 breast tumor tissues. The tumorigenic role of miR-1260b in terms of proliferation, apoptosis, and migration of breast cancer cells was investigated using gain- and loss-of-function assays in vitro. Additionally, the potential early diagnosis and treatment monitoring marker of miR-1260b was validated in 129 plasma samples. We found that high miR-1260b expression was markedly associated with bulky tumor size, advanced stage, and lymph node invasion. Particularly, the high-miR-1260b-expression group showed shorter overall survival than the low-miR-1260b-expression group. The inhibition of oncogenic miR-1260b induced apoptosis and decreased migration and invasion of MDA-MB-231 cells. CASP8 was revealed as a direct target gene of miR-1260b, which is closely related to apoptosis. Furthermore, miR-1260b expression levels in plasma were significantly higher in patients with breast cancer than in healthy controls. The patients who tested positive for miR-1260b showed 16.3- and 18.2-fold higher risks in the early stage and locally advanced stage, respectively, compared with healthy controls, and the risk was decreased 6.2-fold after neoadjuvant chemotherapy. Taken together, miR-1260b may be a potential novel diagnostic, prognostic, and therapeutic target in breast cancer.

Background Mesenchymal stem cells (MSCs) are pluripotent stromal cells that release extracellular vesicles (EVs). EVs contain various growth factors and antioxidants that can positively affect the surrounding cells. Nanoscale MSC-derived EVs, such as exosomes, have been developed as bio-stable nano-type materials. However, some issues, such as low yield and difficulty in quantification, limit their use. We hypothesized that enhancing exosome production using nanoparticles would stimulate the release of intracellular molecules. Results The aim of this study was to elucidate the molecular mechanisms of exosome generation by comparing the internalization of surface-modified, positively charged nanoparticles and exosome generation from MSCs. We determined that Rab7, a late endosome and auto-phagosome marker, was increased upon exosome expression and was associated with autophagosome formation. Conclusions It was concluded that the nanoparticles we developed were transported to the lysosome by clathrin-mediated endocytosis. additionally, entered nanoparticles stimulated that autophagy related factors to release exosome from the MSC. MSC-derived exosomes using nanoparticles may increase exosome yield and enable the discovery of nanoparticle-induced genetic factors.

Age-related hearing loss (ARHL) is the most common sensory disorder among the elderly, associated with aging and auditory hair cell death due to oxidative-stress-induced mitochondrial dysfunction. Although transgenic mice and long-term aging induction cultures have been used to study ARHL, there are currently no ARHL animal models that can be stimulated by intermittent environmental changes. In this study, an ARHL animal model was established by inducing continuous oxidative stress to promote short-term aging of cells, determined on the basis of expression of hearing-loss-induced phenotypes and aging-related factors. The incidence of hearing loss was significantly higher in dual- and triple-exposure conditions than in intermittent hypoxic conditions, high-fat diet (HFD), or d-galactose injection alone. Continuous oxidative stress and HFD accelerated cellular aging. An increase in Ucp2, usually expressed during mitochondrial dysfunction, was observed. Expression of Cdh23, Slc26a4, Kcnq4, Myo7a, and Myo6, which are ARHL-related factors, were modified by oxidative stress in the cells of the hearing organ. We found that intermittent hypoxia, HFD, and galactose injection accelerated cellular aging in the short term. Thus, we anticipate that the development of this hearing loss animal model, which reflects the effects of intermittent environmental changes, will benefit future research on ARHL.

Additional file 1: Figures S1–S12. Provide the summary of the results characterizing the nanoparticles, electron microscopy images of exosomes, list of primers. The additional information includes detailed experimental materials and synthesis strategies, methods for miRNA analysis, and formulae for exosome quantification.