Hypoxic bone marrow mesenchymal cell-extracellular vesicles containing miR-328-3p promote lung cancer progression via the NF2-mediated Hippo axis.

Lung cancer is the most aggressive tumour afflicting patients on a global scale. Extracellular vesicle (EV)-delivered microRNAs (miRs) have been reported to play critical roles in cancer development. The current study aimed to investigate the role of hypoxic bone marrow mesenchymal cell (BMSC)-derived EVs containing miR-328-3p in lung cancer. miR-328-3p expression was determined in a set of lung cancer tissues by RT-qPCR. BMSCs were infected with lentivirus-mediated miR-328-3p knock-down and then cultured in normoxic or hypoxic conditions, followed by isolation of EVs. Following ectopic expression and depletion experiments in lung cancer cells, the biological functions of miR-328-3p were analysed using CCK-8 assay, flow cytometry and Transwell assay. Xenograft in nude mice was performed to test the in vivo effects of miR-328-3p delivered by hypoxic BMSC-derived EVs on tumour growth of lung cancer. Finally, the expression of circulating miR-328-3p was detected in the serum of lung cancer patients. miR-328-3p was highly expressed in EVs derived from hypoxic BMSCs. miR-328-3p was delivered to lung cancer cells by hypoxic BMSC-derived EVs, thereby promoting lung cancer cell proliferation, invasion, migration and epithelial-mesenchymal transition. miR-328-3p targeted NF2 to inactivate the Hippo pathway. Moreover, EV-delivered miR-328-3p increased tumour growth in vivo. Additionally, circulating miR-328-3p was bioactive in the serum of lung cancer patients. Taken together, our results demonstrated that hypoxic BMSC-derived EVs could deliver miR-328-3p to lung cancer cells and that miR-328-3p targets the NF2 gene, thereby inhibiting the Hippo pathway to ultimately promote the occurrence and progression of lung cancer.

Liu X ，Jiang F ，Wang Z ，Tang L ，Zou B ，Xu P ，Yu T ... -  《-》

microRNA-148a-3p in extracellular vesicles derived from bone marrow mesenchymal stem cells suppresses SMURF1 to prevent osteonecrosis of femoral head.

Extracellular vesicle (EV)-associated microRNAs (miRNAs) have been found as the important biomarkers participating in the development of osteonecrosis of the femoral head (ONFH). Consequently, this study sought to examine the underlying mechanism of bone marrow mesenchymal stem cell (BMSC)-derived EVs containing miR-148a-3p in ONFH. The ONFH rat models were established. Reverse transcription quantitative polymerase chain reaction (RT-qPCR) and Western blot analysis were applied to detect miR-148a-3p, Smad ubiquitination regulatory factor 1 (SMURF1), SMAD7 and B-cell CLL/lymphoma 2 (BCL2) expression, followed by determination of relationship between miR-148a-3p and SMURF1. BMSCs were isolated from normal rats and ONFH rats, and EVs were extracted from BMSCs of normal rats. BMSCs from ONFH rats were treated with mimic, inhibitor, small interfering RNA or EVs from miR-148a-3p mimic-treated BMSCs from normal rats (BMSC-EV-miR-148a-3p mimic). Cell Counting Kit-8 and alizarin red staining were utilized to detect cell viability and osteogenic differentiation of BMSCs. ONFH rats were injected with BMSC-EV-miR-148a-3p mimic to explore the function of BMSC-EV-delivered miR-148a-3p in vivo. miR-148a-3p was down-regulated in BMSCs and EVs from ONFH rats following decreased BMSCs viability and osteogenic differentiation. SMURF1 was a target gene of miR-148a-3p, and resulted in ubiquitination and degradation of SMAD7 to decreased BCL2 expression. The proliferation and differentiation of BMSCs were promoted by BMSC-EV-miR-148a-3p mimic or SMURF1 silencing. Additionally, BMSC-EV-miR-148a-3p mimic increased cell proliferation and osteogenic response, diminished SMURF1 expression, and elevated SMAD7 and BCL2 expression in ONFH rats. Collectively, miR-148a-3p overexpressed in BMSC-EVs promoted SMAD7 and BCL2 expression by inhibiting SMURF1, thus alleviating ONFH.

Huang S ，Li Y ，Wu P ，Xiao Y ，Duan N ，Quan J ，Du W ... -  《-》

Extracellular vesicles carrying miR-193a derived from mesenchymal stem cells impede cell proliferation, migration and invasion of colon cancer by downregulating FAK.

MicroRNA (miR) deregulation is frequently seen in colon cancer. In this study, we sought to investigate biological effects of miR-193a on colon cancer and its underlying mechanism. Microarray analysis was conducted to obtain the differentially expressed miRs and their target genes in colon cancer. Bone-marrow derived mesenchymal stem cells (MSCs) and extracellular vesicles (EVs) were obtained. The functional roles of miR-193a and FAK in colon cancer were determined using loss- and gain-function experiments. The cell proliferation, and migration and invasion were evaluated by CCK-8 and Transwell assay respectively. Dual-luciferase reporter assay was performed to confirm the targeting relationship between miR-193a and FAK. Furthermore, in vivo experiment was conducted to test the roles of EV miR-193a in colon cancer growth, followed by determination of PCNA, MMP-2, and MMP-9 protein expression using Western blot analysis. MiR-193a was downregulated, whereas FAK was upregulated in colon cancer. MiR-193a upregulation or FAK downregulation inhibited proliferation, migration and invasion of colon cancer cells. miR-193a could downregulate FAK. Upregulation of EV miR-193a was observed to impede proliferation, migration and invasion of colon cancer cells in vitro and in vivo, accompanied by decreased PCNA, MMP-2, and MMP-9 expression. In summary, EV miR-193a derived from MSCs impeded colon cancer progression by targeting FAK, thus suggesting a new potential strategy for colon cancer treatment.

Ying H ，Lin F ，Ding R ，Wang W ，Hong W ... -  《-》

Extracellular vesicles-encapsulated microRNA-29b-3p from bone marrow-derived mesenchymal stem cells promotes fracture healing via modulation of the PTEN/PI3K/AKT axis.

Bone marrow-derived mesenchymal stem cells (BM-MSCs) are well-established as vital regulators of fracture healing, whereas angiogenesis is one of the critical processes during the course of bone healing. Accordingly, the current study sought to determine the functions of microRNA (miR)-29b-3p from BM-MSCs-derived extracellular vesicles (EVs) on the angiogenesis of fracture healing via the PTEN/PI3K/AKT axis. Firstly, BM-MSCs-EVs were extracted and identified. The lentiviral protocol was adopted to construct miR-29b-3pKD-BMSCs or miR-negative control-BMSCs, which were then co-cultured with human umbilical vein endothelial cells (HUVECs) in vitro to determine the roles of EVs-encapsulated miR-29b-3p on the proliferation, migration, and angiogenesis of HUVECs in vitro with the help of a CCK-8 assay, scratch test, and tube formation assay. Subsequent database prediction, luciferase activity assay, RT-qPCR, and Western blot assay findings identified the downstream target gene of miR-29b-3p, PTEN, and a signaling pathway, PI3K/AKT. Furthermore, the application of si-PTEN attenuated the effects induced by miR-29b-3pKD-EVs. Finally, a mouse model of femoral fracture was established with a locally instilled injection of equal volumes of BM-MSCs-EVs and miR-29b-3pKD-BM-MSCs-EVs. Notably, the mice treated with BMSC-EVs presented with enhanced neovascularization at the fracture site, in addition to increased bone volume (BV), BV/tissue volume, and mean bone mineral density; whereas miR-29b-3pKD-BMSCs-EVs-treated mice exhibited decreased vessel density with poor fracture healing capacity. Collectively, our findings elicited that BM-MSCs-EVs carrying miR-29b-3p were endocytosed by HUVECs, which consequently suppressed the PTEN expression and activated the PI3K/AKT pathway, thereby promoting HUVEC proliferation, migration, and angiogenesis, and ultimately facilitating fracture healing.

Yang J ，Gao J ，Gao F ，Zhao Y ，Deng B ，Mu X ，Xu L ... -  《-》

Hypoxic BMSC-derived exosomal miRNAs promote metastasis of lung cancer cells via STAT3-induced EMT.

Zhang X ，Sai B ，Wang F ，Wang L ，Wang Y ，Zheng L ，Li G ，Tang J ，Xiang J ... -  《Molecular Cancer》