Exosomal miR-21-5p derived from bone marrow mesenchymal stem cells promote osteosarcoma cell proliferation and invasion by targeting PIK3R1

Mesenchymal stem cells (MSCs) are a class of pluripotent cells that can release a large number of exosomes which act as paracrine mediators in tumour-associated microenvironment. However, the role of MSC-derived exosomes in pathogenesis and progression of cancer cells especially osteosarcoma has not been thoroughly clarified until now. In this study, we established a co-culture model for human bone marrow-derived MSCs with osteosarcoma cells, then extraction of exosomes from induced MSCs and study the role of MSC-derived exosomes in the progression of osteosarcoma cell. The aim of this study was to address potential cell biological effects between MSCs and osteosarcoma cells. The results showed that MSC-derived exosomes can significantly promote osteosarcoma cells’ proliferation and invasion. We also found that miR-21-5p was significantly over-expressed in MSCs and MSC-derived exosomes by quantitative real-time polymerase chain reaction (qRT-PCR), compared with human foetal osteoblastic cells hFOB1.19. MSC-derived exosomes transfected with miR-21-5p could significantly enhance the proliferation and invasion of osteosarcoma cells in vitro and in vivo. Bioinformatics analysis and dual-luciferase reporter gene assays validated the targeted relationship between exosomal miR-21-5p and PIK3R1; we further demonstrated that miR-21-5p-abundant exosomes derived human bone marrow MSCs could activate PI3K/Akt/mTOR pathway by suppressing PIK3R1 expression in osteosarcoma cells. In summary, our study provides new insights into the interaction between human bone marrow MSCs and osteosarcoma cells in tumour-associated microenvironment.     

Pseudogene PTENP1 sponges miR-214 to regulate the expression of PTEN to modulate osteoclast differentiation and attenuate osteoporosis

Background aimsOsteoporosis (OP) is a common bone metabolic disease with a high incidence. Our study aimed to explore the pseudogene PTENP1/miR-214/PTEN axis to modulate the osteoclast differentiation in osteoporosis.MethodsPatients with osteoporosis were recruited in our study, and RANKL-induced osteoclast differentiation and ovariectomy-induced osteoporosis mouse model were established in vitro and in vivo, respectively.ResultsPseudogene PTENP1 and PTEN were significantly down-regulated and miR-214 was up-regulated in osteoporosis patients. In addition, overexpression of PTENP1 or silence of miR-214 inhibited the expression levels of osteoclast specific markers and osteoclast differentiation induced by RANKL. Overexpression of PTENP1 or silence of miR-214 also inhibited the levels of phosphorylation of PI3K and AKT, p65 nuclear translocation, IκBα degradation and the expression level of NFATc1. AlsoSilence of PTENP1 or overexpression of miR-214 induced the osteoclast differentiation under normal physiological condition. Pseudogene PTENP1 sponged miR-214 to regulate the expression of PTEN.ConclusionsIn an ovariectomy-induced osteoporosis mouse model, obvious pathological changes in bone tissues were found, and bone marrow mononuclear cells in this group were more likely to differentiate into osteoclasts. Therefore, pseudogene PTENP1 sponged miR-214 to regulate the expression of PTEN to inhibit osteoclast differentiation and attenuate osteoporosis by suppressing the PI3K/AKT/NF-κB signaling pathway.     

miR-125a/b inhibits tumor-associated macrophages mediated in cancer stem cells of hepatocellular carcinoma by targeting CD90

Cancer stem cells promote tumorigenesis and progression of hepatocellular carcinoma (HCC). Recently, emerging evidence indicates tumor-associated macrophages (TAMs) play an important role in tumor progression. However, TAMs often occurs with unknown mechanisms. As an important mediator in intercellular communications, exosomes secreted by host cells mediate the exchange of genetic materials and proteins, which involves tumor aggressiveness. The aim of the study was to investigate whether exosomes derived from TAMs mediate stem cell properties in HCC. TAMs were isolated from the tissues of HCC. microRNA (miRNA) expression profiles of TAMs were analyzed using miRNA microarray. In vitro cell coculture was further conducted to investigate the crosstalk between TAMs and tumor cells mediated by TAMs exosomes. In this study, we showed that TAMs exosomes promote HCC cell proliferation and stem cell properties. Using miRNA profiles assay, we identified significantly lower levels of miR-125a and miR-125b in exosomes and cell lysate isolated from TAMs. Functional studies revealed that the HCC cells were treated with TAM exosomes or transfected with miR-125a/b suppressed cell proliferation and stem cell properties by targeting CD90, a stem cell marker of HCC stem cells. The study indicated that miR-125a/b targeting CD90 played important roles in cancer stem cells of HCC.     

长链非编码RNAIFNG-AS1靶向miR-19b-1-5p调控oxLDL诱导的血管内皮细胞增殖、凋亡的机制研究

为了探讨长链非编码RNA干扰素活化基因的反义核糖核酸(lncRNA IFNG-AS1)对氧化型低密度脂蛋白(oxLDL)诱导的人脐静脉血管内皮细胞EVC-304增殖、凋亡的影响和调控机制,该研究采用100 μg/mL的oxLDL分别处理转染si-IFNG-AS1、miR-19b-1-5p mimics或共转染si-IF...     

Notoginsenoside R1 protects oxygen and glucose deprivation-induced injury by upregulation of miR-21 in cardiomyocytes

Notoginsenoside R1 (NG-R1) is a major component of Panax notoginseng, which has been used clinically for the treatment of diabetic nephropathy for centuries in China. This study aimed to reveal the functional impacts and the underlying mechanisms of NG-R1 on oxygen-glucose deprivation (OGD)-injured cardiomyocytes. Rat cardiomyocyte line H9c2 and primary cardiomyocytes were subjected to OGD with or without NG-R1 treatment. The expression levels of miR-21 and phosphatase and tensin homolog (PTEN) in the cell were altered by microRNA, vector or short-hairpin RNA transfections. Thereafter, changes in cell viability, apoptosis, and PI3K/AKT signaling were monitored. NG-R1 with low concentrations had no impact on H9c2 cells viability, but 80 μM of NG-R1 significantly reduced cell viability. NG-R1 (20 μM) protected H9c2 cells and primary cardiomyocytes against OGD-induced cell damage, as cell viability was increased, apoptotic cell rate was reduced, and Bax, cleaved caspase-3 and -9 were downregulated by addition of NG-R1. MiR-21 was low expressed in response to OGD exposure, while was highly expressed by NG-R1 treatment. PTEN was a direct target of miR-21. More interestingly, OGD-induced cell damage could be recovered by miR-21 overexpression or PTEN silence. Furthermore, PTEN silence recovered OGD-blocked PI3K/AKT signaling pathway. To conclude, this study demonstrated that NG-R1 exerted remarkable benefits in reduction of OGD-induced cardiomyocyte loss. The cardioprotective actions of NG-R1 possibly via upregulation of miR-21, repressing the expression of miR-21's target PTEN and thereby preventing the blockage of PI3K/AKT signaling pathway.     

miR-29b regulates migration of human breast cancer cells

microRNAs (miRNAs) are short non-coding RNAs that regulate gene expression by targeting mRNAs, inhibiting the expression of the associated proteins. Although a role for aberrant miRNA expression in cancer has been postulated, the pathophysiologic role and relevance of aberrantly expressed miRNAs in tumor biology has not been established. We evaluated the expression pattern of miRNAs in human breast cancer cells by qPCR, finding out an up-regulated miRNA miR-29b and studying its biological effect by migration assay. We defined a target gene PTEN by bioinformatics approach and western blot. In breast cancer cell line MDA-MB-231 cell, which migrate faster than MCF-7, we observed that miR-29b was highly over-expressed. Inhibition of miR-29b in cultured cells increased the expression of the phosphatase and tensin homolog (PTEN) tumor suppressor, promoting apoptosis, decreasing migration, and decreasing invasion. In contrast, enhanced miR-29b expression by transfection with pre-miR-29b decreased the expression of PTEN and impaired apoptosis, increasing tumor cell migration and invasion. Moreover, PTEN was shown to be a direct target of miR-29b and was also shown to contribute to the miR-29b-mediated effects on cell invasion. Modulation of miR-29b altered the role of PTEN involved in cell migration and invasion. Aberrant expression of miR-29b, which modulates PTEN expression, can contribute to migration, invasion, and anti-apoptosis.     

miR-21 promotes proliferation and inhibits apoptosis of hepatic stellate cells through targeting PTEN/PI3K/AKT pathway

Abstract

To investigate the effect of microRNA 21 (miR-21) on hepatic stellate cells (HSCs) proliferation and apoptosis, and further to study its potential mechanisms. LX-2 cells were divided into miR-21 mimic group (Mimic), miR-21 mimic negative control group (NM), miR-21 inhibitor group (Inhibitor), miR-21 inhibitor negative control group (NC), and blank control group (Control). The cell proliferation was detected by CCK-8 assay and the cell migration and invasion were detected by scratch and transwell assay. Cell cycle and apoptosis were detected by flow cytometry. The levels of interleukin (IL)-6, tumor necrosis factor (TNF)-α, and transforming growth factor (TGF)-β1 were detected by enzyme-linked immunosorbent assay (ELISA). Proliferation, apoptosis, and phosphatase and tensin homolog (PTEN)/phosphoinositide 3-kinase (PI3K)/protein kinase B (AKT) signaling pathway related genes and proteins were detected by quantitative real-time polymerase chain reaction (qRT-PCR) and western blot, respectively. The cells proliferation, migration, and invasion were promoted in Mimic group. The levels of IL-6, TNF-α, and TGF-β1 were increased after miR-21 administration. The expression of α-smooth muscle actin (SMA) and collagen 1 (Colla1) were increased, while Bax/B-cell lymphoma (Bcl)-2 ratio and programed cell death 4 (PDCD4) were reduced after miR?21 treatment. Meanwhile, the mRNA and protein expression of PTEN were reduced and PI3K/AKT pathway been promoted. Our study demonstrated that miR-21 could promote proliferation and inhibit apoptosis of HSCs, and its mechanism may be related to PTEN/PI3K/AKT pathway.     

MiR-1297下调PTEN的表达参与子宫内膜癌变

已有研究证明,抑癌子PTEN（phosphatase and tensin homolog）缺失或表达下调可引起子宫内膜癌变;在喉鳞状细胞癌中miR-1297可下调PTEN的表达。然而,miR-1297下调PTEN的机制,以及是否miR-1297靶向抑制PTEN参与子宫内膜癌变尚未见报道。本研究证明,miR-1297靶向抑制PTEN基因的表达参与子宫内膜癌变。收集临床病理检查确诊为子宫内膜腺癌的癌组织及癌旁组织18例。实时定量PCR（RT-qPCR）及Western印迹结果显示,与癌旁子宫内膜比较,子宫内膜癌组织miR-1297高表达,而PTEN则呈低表达或缺失。内膜癌和癌旁内膜组织中,miR-1297与PTEN表达水平的散点图分析揭示,miR-1297的表达水平与PTEN的表达水平呈明显的负相关（内膜癌：miR-1297与PTEN的相关系数r=-0.6928,P=0.0438;癌旁组织：相关系数r=-0.4085,P < 0.0001)。报告酶活性测定显示,与对照比较,pGL3-PTEN-3′-UTR-1/2/3加miR-1297模拟物共转染后,荧光素酶活性在转染的Ishikawa和ECC-1细胞中分别降低了约21%（P=0.0196）和17%（P=0.0306）;相反,转染miR-1297抑制物后,两种细胞的荧光素酶活性分别升高约59%（Ishikawa：P=0.0014）和50%（ECC-1： P=0.0025）。结果提示,miR-1297可通过特异识别PTEN mRNA的3′-UTR,抑制PTEN的表达。基因转染结合Western印迹结果证明,在原代子宫内膜细胞中,过表达miR-1297模拟物导致PTEN蛋白表达下调,而其下游底物分子--磷酸化的AKT（p-AKT）表达上调;而过表达miR-1297抑制物后,PTEN表达上调,p-AKT表达下调。Connexin V/PI双染结合流式分析证明,与对照细胞（3%细胞凋亡）比较,在子宫内膜癌细胞系Ishikawa中,敲减miR-1297表达后细胞调亡明显增加（至10%）,这可能与抑制miR-1297后PTEN的表达上调有关。上述结果提示,miR-1297在子宫内膜癌高表达,而PTEN低表达。上述结果还提示,miR-1297作为一个促癌子可通过特异识别PTEN mRNA的3′-UTR,抑制PTEN的表达,促进AKT磷酸化/激活,从而促进内膜癌的发生,这可能是子宫内膜癌变的发生原因之一。     

Up-regulation of miR-21 mediates resistance to trastuzumab therapy for breast cancer

Trastuzumab resistance emerges to be a major issue in anti-human epidermal growth factor receptor 2 (HER2) therapy for breast cancers. Here, we demonstrated that miR-21 expression was up-regulated and its function was elevated in HER2(+) BT474, SKBR3, and MDA-MB-453 breast cancer cells that are induced to acquire trastuzumab resistance by long-term exposure to the antibody, whereas protein expression of the PTEN gene, a miR-21 target, was reduced. Blocking the action of miR-21 with antisense oligonucleotides re-sensitized the resistant cells to the therapeutic activities of trastuzumab by inducing growth arrest, proliferation inhibition, and G(1)-S cell cycle checking in the presence of the antibody. Ectopic expression of miR-21 in HER2(+) breast cancer cells confers resistance to trastuzumab. Rescuing PTEN expression with a p3XFLAG-PTEN-mut construct with deleted miR-21 targeting sequence at its 3' UTR restored the growth inhibition of trastuzumab in the resistant cells by inducing PTEN activation and AKT inhibition. In vivo, administering miR-21 antisense oligonucleotides restored trastuzumab sensitivity in the resistant breast cancer xenografts by inducing PTEN expression, whereas injection of miR-21 mimics conferred trastuzumab resistant in the sensitive breast tumors via PTEN silence. Up-regulatin of miR-21 in tumor biopsies obtained from patients receiving pre-operative trastuzumab therapy was associated with poor trastuzumab response. Therefore, miR-21 overexpression contributes to trastuzumab resistance in HER2(+) breast cancers and antagonizing miR-21 demonstrates therapeutic potential by sensitizing the malignancy to anti-HER2 treatment.     

Exosomal miR-150 partially attenuated acute lung injury by mediating microvascular endothelial cells and MAPK pathway

Background: Acute lung injury (ALI) is a respiratory disease with high morbidity and mortality rates. Currently, there is no effective treatment to complement mechanical ventilation. Exosomes and microRNAs (miRNAs) are promising agents for the management of this disease.Methods: Exosomes were isolated from mouse bone marrow stromal stem cells (BMSCs). The levels of two miRNAs, miR-542-3P and miR-150, in exosomes were determined using RT-PCR, and miR-150 was selected for further study. ALI model was established in mice using lipopolysaccharides, and then, they were treated with saline, exosomes, miRNA agomirs, or miRNA antagomirs. The concentrations of TNF-α, IL-6, and IL-1β and the number of neutrophils and macrophages in the bronchoalveolar lavage fluid were measured. The wet/dry weight ratio of the lung tissue was calculated, and tissue pathology and apoptosis were observed using hematoxylin and eosin and terminal deoxynucleotidyl transferase dUTP nick-end labeling staining. CD34 and VE-cadherin expression was detected using immunofluorescence. Proteins associated with apoptosis and MAPK signaling were detected using Western blotting, and miR-150 expression in lung tissue was evaluated using RT-PCR.Results: We successfully isolated BMSCs and exosomes and showed that the level of miR-150 was significantly higher than that of miR-542-3p. Exosomes and miR-150 reduced inflammation and lung edema while maintaining the integrity of the alveolar structure. They also mitigated microvascular endothelial cell injury by regulating the caspase-3, Bax/Bcl-2, and MAPK signaling.Conclusions: Exosomal miR-150 attenuates lipopolysaccharide-induced ALI through the MAPK pathway.     

Blockage of transferred exosome-shuttled miR-494 inhibits melanoma growth and metastasis

There is emerging evidence of bioactive material transport by exosomes in melanoma. However, the functions of exosome content underlying such cancer progression remain largely unknown. We aimed at determining whether exosome secretion contributes to cellular microRNA-494 (miR-494) loss and investigated the roles of miR-494 in melanoma progression. The exosomes from blood serum and cell culture conditioned media were separated by ultracentrifugation. A short hairpin RNA was used to silence rab27a for inhibiting exosome release. To address the functional role of exosomal miR-494, we assessed cell proliferation, migration, invasion capabilities, and cell apoptosis. Finally, subcutaneous xenograft and lung-metastasis models were constructed to determine the effect of exosomal miR-494 in vivo. Based on long noncoding RNA microarray analysis of melanocyte and melanoma-derived exosomes from the Gene Expression Omnibus database, we discovered that miR-494 was enriched in melanoma-derived exosomes. And miR-494 was increased in exosomes secreted from melanoma patients’ serum and A375 cells. Rab27a depletion reduced exosome secretion and rescued the abundance of cellular miR-494. Functional studies revealed that knockdown of rab27a and subsequent accumulation of miR-494 significantly suppressed the malignant phenotypes of melanoma cells via inducing cell apoptosis. Nude mice experiments confirmed that tumor growth and metastasis were suppressed by increasing miR-494 accumulation after rab27a depletion. In conclusion, blocking transferred exosome-shuttled miR-494 is a potential therapeutic option for melanoma.     

miR-30a和miR-30b靶向GW182的生物学功能研究

目的：通过证明miR-30a、miR-30b靶向GW182,探索HeLa细胞中miR-30a、miR-30b及GW182的生物学功能。方法：生物信息学预测分析表明GW182的3＇UTR区存在4个保守的miR-30a、miR-30b靶位点,将含有靶位点的序列片段构建到萤光素酶报告载体中,检测miR-30a、miR-30b与靶位点的结合情况;用阳离子脂质体转染GW182 siRNA和miR-30a、miR-30b mimics,检测GW182下游功能的变化。结果：miR-30a、miR-30b能够靶向GW182;qPCR及Western印迹证明miR-30a、miR-30b可以在mRNA与蛋白水平上降低GW182的表达,同时影响GW182所参与的miRNA/siRNA对靶基因的抑制作用。结论：GW182是miR-30a、miR-30b的靶基因,揭示了miR-30a、miR-30b通过靶向GW182影响miRNA/siRNA作用途径的新功能。     

MEG3 interacted with miR-494 to repress bladder cancer progression through targeting PTEN

The long noncoding RNA MEG3 is a significant tumor-suppressive gene in various tumors. But its biological role in bladder cancer remains uninvestigated. Herein, the biological mechanism of MEG3 in bladder cancer pathogenesis was explored. First, the expression of MEG3 in bladder cancer cells was examined, and we found that it was significantly reduced. In addition, in bladder cancer cells, we observed htat miR-494 was increased. Then, MEG3 was overexpressed in UMUC3 and SW780 cells and it could negatively modulate miR-494 expression. Bladder cancer cell proliferation was repressed, cell apoptosis was triggered and meanwhile, the cell cycle was remarkably arrested by the overexpression of MEG3. Moreover, the increase of MEG3 suppressed bladder cancer cell migration and invasion capacity. MEG3 can sponge miR-494 and the binding sites between them were confirmed by carrying out a series of functional assays. Furthermore, PTEN was speculated as a putative target of miR-494. Meanwhile, we found that miR-494 inhibitors induced PTEN. Finally, in vivo assays were conducted to prove that MEG3 can restrain bladder tumor growth by modulating miR-494 and PTEN. In conclusion, it was suggested MEG3 can interact with miR-494 to regulate PTEN in bladder cancer development.     

MiR-200a is involved in proliferation and apoptosis in the human endometrial adenocarcinoma cell line HEC-1B by targeting the tumor suppressor PTEN

Abnormal cell proliferation is a main driver of tumor formation and development, which involves the deletion, mutation, and downregulation of tumor suppressor genes. One study recently demonstrated that miR-200a plays an oncogenic role by inhibiting phosphatase and tensin homolog deleted on chromosome ten (PTEN) expression. In the human endometrial adenocarcinoma cell line HEC-1B, suppression of miR-200a expression inhibited cell proliferation and promoted apoptosis, whereas its over-expression had no effect on proliferation and apoptosis. Furthermore, inhibition or over-expression of miR-200a increased or reduced the expression of PTEN, respectively, with no change in PTEN mRNA levels. These effects were achieved by directly targeting miR-200a to the 3′ untranslated region of the PTEN mRNA to inhibit its translation. Taken together, we propose that in HEC-1B cells, miR-200a functions as an oncogene, affecting proliferation and apoptosis by regulating the expression of the tumor suppressor PTEN at the translational level.     

Dissimilar microRNA-21 functions and targets in trophoblastic cell lines of different origin

Trophoblast cells express a singular miRNA expression profile which varies during pregnancy and whose alteration may be associated with pregnancy complications. miR-21, a widely known oncomir, is highly expressed in human placenta but its role in regulating trophoblast cells remains unclear. The aim of this study was to investigate miR-21 functions and targets in HTR-8/SVneo immortalized trophoblast and JEG-3 choriocarcinoma cells, which are trophoblast cell models that differ in their cellular origin. Cells were transfected with miR-21-antagomir, -mimic or their respective controls. Following, cell proliferation (BrdU), migration (Transwell and scratch wound-healing assays), invasion (Matrigel assays) and apoptosis (flow cytometry, TUNEL assay and Western blotting) were assessed. Expression of the potential miR-21 targets phosphatase and tensin homolog (PTEN) and programmed cell death 4 (PDCD4) were analyzed by Western blotting. Inhibition of miR-21 decreased cell proliferation, migration, and invasion in JEG-3 and HTR-8/SVneo cells and additionally, induced apoptosis in JEG-3 cells. Silencing of miR-21 enhanced PDCD4 expression only in JEG-3 cells, and PTEN expression only in HTR-8/SVneo cells. Inhibition of miR-21 significantly increased phosphorylation of AKT in HTR-8/SVneo cells. In conclusion, miR-21 has cell-specific targets depending upon the origin of trophoblastic cells. Furthermore, miR-21 regulates major cellular processes including cell growth, migration, invasion and apoptosis suggesting that its impairment may lead to placental disorders.     

microRNA-125b and its downstream Smurf1/KLF2/ATF2 axis as important promoters on neurological function recovery in rats with spinal cord injury

The purpose of this study is to investigate the role of microRNA-125b (miR-125b) and its mechanism in spinal cord injury (SCI) by targeting Smurf1. After loss- and gain-function approaches were conducted in SCI rat models and neural stem cells (NSCs) isolated from foetal rats, the Basso-Beattie-Bresnahan (BBB) score was calculated, and related protein expression was determined by Western blot analysis and cell apoptosis by TUNEL staining. NSC viability was detected by CCK-8, migration abilities by Transwell assay and apoptosis by flow cytometry. The relationship between miR-125b, Smurf1 and KLF2 was evaluated by dual-luciferase reporter gene experiments, Co-IP and in vivo ubiquitin modification assays. Inhibition of miR-125b and KLF2 and the up-regulation of Smurf1 and ATF2 were observed in SCI rats. BBB scores were elevated, the expression of Nestin, NeuN, GFAP, NF-200 and Bcl-2 protein was enhanced but that of Bax protein was reduced, and cell apoptosis was inhibited in SCI rats after up-regulating miR-125b or silencing ATF2. Smurf1 was a target gene of miR-125b, which promoted KLF2 degradation through its E3 ubiquitin ligase function, and KLF2 repressed the expression of ATF2 in NSCs. The results in vivo were replicated in vitro. miR-125b overexpression promotes neurological function recovery after SCI.