Exosomes-Derived MiR-302b Suppresses Lung Cancer Cell Proliferation and Migration via TGFβRII Inhibition

221

157

Background/Aims: Treatment of breast cancer remains a clinical challenge. This study aims to validate exosomal microRNA-1246 (miR-1246) as a serum biomarker for breast cancer and understand the underlying mechanism in breast cancer progression. Methods: The expression levels of endogenous and exosomal miRNAs were examined by real time PCR, and the expression level of the target protein was detected by western blot. Scanning electron and confocal microscopy were used to characterize exosomes and to study their uptake and transfer. Luciferase reporter plasmids and its mutant were used to confirm direct targeting. Furthermore, the functional significance of exosomal miR-1246 was estimated by invasion assay and cell viability assay. Results: In this study, we demonstrate that exosomes carrying microRNA can be transferred among different cell lines through direct uptake. miR-1246 is highly expressed in metastatic breast cancer MDA-MB-231 cells compared to non-metastatic breast cancer cells or non-malignant breast cells. Moreover, miR-1246 can suppress the expression level of its target gene, Cyclin-G2 (CCNG2), indicating its functional significance. Finally, treatment with exosomes derived from MDA-MB-231 cells could enhance the viability, migration and chemotherapy resistance of non-malignant HMLE cells. Conclusions: Together, our results support an important role of exosomes and exosomal miRNAs in regulating breast tumor progression, which highlights their potential for applications in miRNA-based therapeutics.

Section: Discussionsupporting

confidence: 52%

Exosomal MicroRNA MiR-1246 Promotes Cell Proliferation, Invasion and Drug Resistance by Targeting CCNG2 in Breast Cancer

Zhao

Tang

et al. 2017

221

157

“…Exosomes (30- to 100-nm small membrane vesicles) derived from ADSCs have been used to treat AMI [7, 8]. Exosome-mediated cell-cell microcommunication through inherent molecules such as nucleotides, proteins, and bioactive lipids has been reported [9-11]. Exosomes play an important role as key transporters of paracrine factors in angiogenesis, immune regulation, and tissue regeneration [12-14].…”

Section: Introductionmentioning

confidence: 99%

Exosomes from MiR-126-Overexpressing Adscs Are Therapeutic in Relieving Acute Myocardial Ischaemic Injury

Luo¹,

Guo²,

Liu³

et al. 2017

216

151

Background/Aims: Recent studies have indicated that exosomes play an important role in adipose-derived stem cell (ADSC) transplant-mediated ischaemic heart disease therapy. However, the treatment effect is not obvious. The aim of this study is to investigate whether ADSC-derived exosomes enriched with microRNA (miR)-126 have a more protective effect on acute myocardial infarction (AMI). Methods: Exosomes were characterized by transmission electron microscopy, and the exosome particles were further examined using nanoparticle tracking analyses. A rat model of myocardial infarction and in vitro model of hypoxia-induced H9c2 myocardial cell injury were established to study the protective mechanism of exosomes from miR-126-overexpressing ADSCs. Results: The in vitro results showed that exosomes derived from miR-126-overexpressing ADSCs decreased H9c2 myocardial cell injury by reducing inflammation factor expression during hypoxia induction. The miR-126-enriched exosomes also decreased the expression of fibrosis-related proteins of H9c2 cells under hypoxic conditions. Matrigel® and Transwell® assays showed that miR-126-enriched exosomes significantly promoted microvascular generation and migration, respectively. In vivo studies confirmed that exosomes derived from ADSCs significantly decreased the myocardial injury area of infarction, especially after miR-126-enriched exosome treatment. Cardiac fibrosis and inflammatory cytokine expression were also decreased after treatment with miR-126-enriched exosomes. However, blood vessel formation was promoted in the infarction region of AMI rats. Conclusions: The results suggested that the expression of miR-126-enhanced ADSC-derived exosomes prevented myocardial damage by protecting myocardial cells from apoptosis, inflammation, fibrosis, and increased angiogenesis.

“…Carrying signalling molecules [14,15], exosomes have been accepted as markers of disease [16,17] or information vectors [18]. Exosomes isolated from adipose tissue mediated adipose tissue inflammation in a murine model [19].…”

Section: Introductionmentioning

confidence: 99%

Adipocyte-Derived Exosomes Carrying Sonic Hedgehog Mediate M1 Macrophage Polarization-Induced Insulin Resistance via Ptch and PI3K Pathways

Song

Han

Chen

et al. 2018

Background/Aims: Adipocyte-derived exosomes (ADEs) stimulate the activation of macrophages and contribute to the development of insulin resistance. Sonic Hedgehog (Shh) is an exosome-carrying protein and stimulates macrophages to secrete inflammatory cytokines. However, the impact of ADEs carrying Shh on the pro-inflammatory activation of macrophages and consequently, adipocyte insulin resistance is unclear. Methods: 3T3-L1 adipocytes were cultured with high glucose and insulin to imitate the pathogeny of insulin resistance. ADEs were isolated from conditioned media of 3T3-L1 adipocytes via differential ultracentrifugation. We explored the role of ADEs carrying Shh in the polarization of macrophages by flow cytometry. Western blot and electrophoretic mobility shift assay (EMSA) were performed to determine the activation of Shh-mediated signalling pathways. The effects of ADE-treated macrophages on adipocyte insulin signalling were studied by Western blot. Results: We found that circulating Shh-positive exosomes were increased in type 2 diabetes patients. High glucose and insulin increased the secretion of Shh-positive ADEs. The ADEs carrying Shh induced pro-inflammatory or M1 polarization of bone marrow-derived macrophages (BMDM) and RAW 264.7 macrophages. Inhibitors of Ptch and PI3K blocked the M1 polarization induced by ADEs, which suggests that ADEs carrying Shh mediated M1 macrophage polarization through the Ptch/PI3K signalling pathway. ADE-treated RAW 264.7 macrophages were subsequently used to assess the effect on insulin signalling in adipocytes. Using a co-culture assay, we showed that both ADE-treated macrophages and exosomes from these macrophages could decrease the expression of insulin-resistant substrate-1 (IRS-1) and hormone-sensitive lipase (HSL) in adipocytes. Inhibitors of Ptch and PI3K blocked the down-regulation of IRS-1 and HSL induced by ADE-treated macrophages. Conclusion: Together, these data indicate that ADEs carrying Shh induce the M1 polarization of macrophages, which contributes to insulin resistance in adipocytes through the Ptch/PI3K pathway.