Transfection Of miR-21 Inhibitor Research Articles

MiR-21 Regulates Immune Balance Mediated by Th17/Treg in Peripheral Blood of Septic Rats during the Early Phase through Apoptosis Pathway.

Objective To study the mechanism by which miR-21 regulates the differentiation and function of Th17/Treg cells in sepsis. Methods A rat model with sepsis was made by cecal ligation and puncture (CLP). Then, some of the septic rats were transfected with miR-21 mimic or inhibitor by liposome. At 48 hours, lymphocytes and plasma from septic rats were isolated for further experimental detection. The expression of miR-21 in lymphocytes was detected by Polymerase Chain Reaction (PCR); the differentiation of Th17/Treg cells was counted by flow cytometry; lymphocyte apoptosis was observed by terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling (TUNEL) assay. The caspase-3/9 proteins were tested by Western blot; IL-10 and IL-17 were detected by enzyme-linked immunosorbent assay (ELISA). Results Compared with the sepsis group (SP group), the Th17 cells increased significantly, the Treg cells decreased significantly, the apoptosis rate of lymphocytes decreased significantly, the mRNA and proteins of caspase-3/9 decreased significantly, the IL-17 decreased, and the IL-10 increased in the sepsis group transfected with miR-21 (SP + miR-21 mimic group). After transfection of miR-21 inhibitor, the results were almost opposite to those of SP + miR-21 mimic group. Conclusions The differentiation and function of Th17/Treg cells were regulated by miR-21 in sepsis through caspase pathway.

Effects of miR-21 Mediating Nerve Cell Adhesion Molecule (NCAM) and Glial Cell-Line Derived Neurotrophic Factor (GDNF) Signals on the Proliferation and Apoptosis of Lung Cancer Cells

Our study assessed the effect of miR-21 mediating Nerve Cell Adhesion Molecule (NCAM) and Glial Cell-line Derived Neurotrophic Factor (GDNF) on the proliferation and apoptosis of lung cancer cells. Lung cancer cell-line H460 cells were grouped as Lung cancer group (LC group) (normal cultivation); Mimic group (SI group) which was transfected with 120 nmol/L miR-21 mimics and liposomes; Inhibitor group (IN group) (transfection of miR-21 inhibitor and liposomes) followed by analysis of cell apoptosis by Hoechst 33258 staining, GDNF level by immunohistochemistry, miR-21 level by qRT-PCR, cell proliferation by CCK-8 and NCAM level by western blot. miR-21 content was significantly increased in SI group, indicating a successful transfection. The nucleus shrinkage rate in IN group and LC group was higher than SI group (P <0.05) and IN group had highest number of apoptotic cells, lowest cell proliferation and NCAM level among three groups (P <0.05). SI group showed significantly higher positive GDNF staining than IN and LC group (both P <0.05). miR-21 promotes H460 cell proliferation and inhibits cell apoptosis by upregulating NCAM and GDNF.

Ginsenoside Rb1 protects cardiomyocytes from oxygen-glucose deprivation injuries by targeting microRNA-21.

Ginsenoside Rb1 (GS-Rb1) is one of the most important active pharmacological extracts of the traditional Chinese medicine, ginseng, and there is extensive evidence of its cardioprotective properties. However, the microRNA (miR) targets of GS-Rb1 and the underlying mechanisms of GS-Rb1 and miR-21 in the progression of cardiomyocyte apoptosis have not been clearly elucidated. The aim of the current study was to investigate the impact of miR-21 and its target gene, programmed cell death protein 4 (PDCD4), on the protective effect of GS-Rb1 in cardiomyocytes injured by oxygen-glucose deprivation (OGD). The miR-21 expression levels were downregulated, and the percentage of the apoptotic cells and reactive oxygen species (ROS) was increased in OGD-cultured neonatal rat cardiomyocytes; however, the effects were reversed by GS-Rb1 treatment. It was demonstrated that GS-Rb1 could reduce intracellular ROS content, and the expression of cytochrome C and the pro-apoptosis protein, apoptosis regulator B-cell lymphoma associated X (Bax) protein while increasing the expression of the anti-apoptosis protein, apoptosis regulator Bcl-2. The target gene, PDCD4, was significantly upregulated in the OGD group; however, the expression of PDCD4 was inhibited by GS-Rb1 treatment. Furthermore, miR-21 inhibitor transfection reduced GS-Rb1-induced miR-21 upregulation compared with the OGD+GS-Rb1 group, indicating that the miR-21 was involved in the anti-apoptotic effect of GS-Rb1 in cardiomyocytes. The results of the current study highlighted that GS-Rb1 could target miR-21 and its target gene, PDCD4, to protect OGD-injured cardiomyocytes. The results of the current study may provide a novel insight for the treatment of myocardial infarction with Traditional Chinese Medicines, involving miRs as targets.

Visfatin increases miR-21 to promote migration in HCC

Hepatocellular carcinoma (HCC) is a common human malignancy. In this study, we aimed to investigate the serum levels of visfatin and miR-21 in HCC patients, to analysis the relationship between the pathological features and the plasma level of visfatin or miR-21, and to explore the roles of visfatin and miR-21 in migration of HCC cells. Our results showed that the serum levels of visfatin and miR-21 were significant higher in HCC patients than healthy subjects. The diagnostic sensitivity of serum visfatin was 82.5% and the specificity was 65.0%. The serum visfatin was significantly associated with the histology and metastasis. Visfatin induced miR-21 expression and cell migration in HepG2 cells. Transfection of miR-21 inhibitor suppressed the visfatin-induced migration in HCC cells. These results suggested that visfatin induced HCC cell migration via upregulation of miR-21, which provides a novel basis for the diagnosis of HCC.

Heregulin-1β Promotes the Synergistic Effect Between Allogenic Skin-Derived Precursor Differentiated Schwann Cells (SKP-SC) and Acellular Nerve Allograft (ANA) in Peripheral Nerve Regeneration Through Inhibiting Mir-21

Previous studies in our lab found that heregulin-1β with SKP-SCs (neurons and Schwann cells differentiated from SKPs) / ANA (acellular nerve allograft) transplantation represented a powerful therapeutic approach, and facilitates the efficacy of ANA in peripheral nerve injury. In this study, our purpose is to explore the mechanism between them. Firstly we transplanted ANA + SKP-SC + heregulin-1β into rats with right sciatic nerve injury and then detected the miR-21 and SOX2 (SRY-like HMG box 2) levels. Then we transfected miR-21 inhibitor in SCs (Schwann cells) which induced in hypoxic condition before harvesting. Then we detected expression of miR-21 and SOX2 using real time-PCR and western blot assay. Results in vivo showed that the expression of miR-21 in rats was inhibited after transplantation of ANA + SKP-SC + heregulin-1β with induced SOX2 accordingly. Then we found miR-21 was increased time dependently in hypoxic SCs with decreased SOX2 accordingly. After miR-21 inhibitor transfection, miR-21 level was reduced and SOX2 was up-regulated. Meanwhile it was also showed that the miR-21 inhibitor induced the hypoxic SCs growth, decreased the apoptosis with cell cycle changing. In conclusion miR-21 and its target gene SOX2 played important role in peripheral nerve injury. Heregulin-1β may increase the synergistic effect between SKP-SC and ANA through inhibiting miR-21 in vivo.

MiR-21 modulates chemosensitivity of tongue squamous cell carcinoma cells to cisplatin by targeting PDCD4

Chemoresistance is a challenge for clinician in management of tongue cancer. Therefore, it is necessary to explore alternative therapeutic methods to overcome drug resistance. miRNAs are endogenous -22nt RNAs that play important regulatory roles by targeting mRNAs. miR-21, an essential oncogenic molecule, is associated with chemosensitivity of several human cancer cells to anticancer agents. In this study, we investigated the effects and molecular mechanisms of miR-21 in chemosensitivity of tongue squamous cell carcinoma cells (TSCC) to cisplatin. miR-21 expression was detected in tongue cancer tissue using RT-PCR and PDCD4 protein expression was measured using immunohistochemistry. miR-21 and(or) PDCD4 depleted cell lines were generated using miR-21 inhibitor and(or) siRNA. The viabilities of treated cells were analyzed using MTT assay. RT-PCR was used to detect miR-21 expression and immunoblotting was used to detect protein levels. Cell cycle and apoptosis were analyzed using propidium iodide (PI) staining and Annexin V/PI staining, respectively. The expression of miR-21 in tumorous tissue was significantly higher compared with adjacent normal tissue and loss of PDCD4 expression was observed in TSCCs. Transfection of miR-21 inhibitor induced sensitivity of TSCC cells (Tca8113 and CAL-27) to cisplatin. TSCC cells transfected with PDCD4 siRNA became more resistant to cisplatin therapy. We found an increase PDCD4 protein level following the transfection of miR-21 inhibitor using Western blot analysis. In addition, the enhanced growth-inhibitory effect by miR-21 inhibitor was weakened after the addition of PDCD4 siRNA. Suppression of miR-21 or PDCD4 could significantly promote or reduce cisplatin-induced apoptosis, respectively. Our data suggest that miR-21 could modulate chemosensitivity of TSCC cells to cisplatin by targeting PDCD4, and miR-21 may serve as a potential target for TSCC therapy.

Phosphatase of regenerating liver-3-signal transducer and activators of transcription 3-miR-21 sighal pathway promotes proliferation and invasion of colon cancer cells

Objective To explore the effect of phosphatase of regenerating liver-3-signal transducer and activators of transcription 3-microRNA-21 (PRL-3-STAT3-miR-21) signal pathway on proliferation and invasion of colon cancer cellsMethods We stablely transfected PRL-3 expressing plasmid and empty plasmid into LoVo colon cancer cells and established two cell lines:LoVo-PRL-3 and LoVo-VC.We used quantitative real-time reverse transcription-polymerase chain reaction (qRT-PCR) to detect the expression of miR-21 in LoVo cells.We also performed transient transfection of PRL-3 into SW480 and CACO2 cells to validate the expression of miR-21.Western blotting was used to detect the effect of PRL-3 on the expression of STAT3.RNA interference was used to knocked down STAT3 in LoVo-PRL-3 cells,after that miR-21 expression was detected.Transient transfection of miR-21mimic into LoVo-VC cells or transient transfection of miR-21 inhibitor into LoVo-PRL-3 cells were performed to evaluate the proliferation and invasive ability of these cells by CCK8 proliferating assay and Transwell chamber assay.Results PRL-3 promoted proliferation of LoVo-PRL-3 cells at 72 h,96 h and invasion of LoVo-PRL-3 cells after 24 h compared with LoVo-VC cells (P＜0.01).In LoVo-PRL-3 cells,pSTAT3 and miR-21 were up-regulated.Knock-down of STAT3 mRNA decreased the expression of miR-21 (P ＜ 0.05).Over-expression of miR-21 promoted proliferation and invasion of LoVo-VC cells (P ＜ 0.01),while knocking down of miR-21 inhibited proliferation and invasion of LoVo-PRL-3 cells (P ＜ 0.05).Conclusion PRL-3-STAT3-miR-21 signal pathway promotes proliferation and invasion of colon cancer cells. Key words: Phosphatase of regenerating liver-3; Signal transducer and activators of transcription 3 ; MicroRNA-21

MicroRNA-21 correlates with tumorigenesis in malignant peripheral nerve sheath tumor (MPNST) via programmed cell death protein 4 (PDCD4)

We investigated the miRNA profile in peripheral nerve tumors and clarified the involvement of miRNA in the development and progression of MPNST in comparison with neurofibroma (NF). In addition, we attempted to seek associations between the miRNA and their potential targets in MPNST. Global miRNA expression profiling was investigated for clinical samples of 6 MPNSTs and 6 NFs. As detected by profiling analysis, the expressions of miR-21 in clinical samples of 12 MPNSTs, 11 NFs, and 5 normal nerves, and 3 MPNST cell lines were compared using quantitative real-time reverse transcription PCR. MPNST cell line (YST-1) was transfected with miR-21 inhibitor to study its effects on cell proliferation, caspase activity, and the expression of miR-21 targets. Analysis of miRNA expression profiles in MPNST and NF revealed significantly altered expression levels of nine miRNAs, one of those, miR-21, and its putative target, programmed cell death protein 4 (PDCD4), were selected for further studies. miR-21 expression level in MPNST was significantly higher than that in NF (P<0.05). In MPNST cells, transfection of miR-21 inhibitor significantly increased caspase activity (P<0.01), significantly suppressed cell growth (P<0.05), and upregulated protein level of PDCD4, indicating that miR-21 inhibitor could induce cell apoptosis of MPNST cells. These results suggest that miR-21 plays an important role in MPNST tumorigenesis and progression through its target, PDCD4. MiR-21 and PDCD4 may be candidate novel therapeutic targets against the development or progression of MPNSTs.

MicroRNA-21 (miR-21) represses tumor suppressor PTEN and promotes growth and invasion in non-small cell lung cancer (NSCLC)

MicroRNAs (miRNAs) are a class of small non-coding RNAs regulating gene expression that play roles in the pathogenesis of human diseases, including malignancy. miR-21, a commonly overexpressed miRNA in very diverse types of malignancies, may affect tumor progression through targeting tumor suppressor genes. We identified the role of miR-21 in non-small cell lung cancer (NSCLC) and to clarify the regulation of PTEN by miR-21 and determine mechanisms of this regulation. Expression of miR-21 and PTEN in 20 paired NSCLC and adjacent non-tumor lung tissues was investigated by qRT-PCR and western blot, respectively. The effect of miR-21 on PTEN expression was assessed in NSCLC cell lines with miR-21 inhibitor to decrease miR-21 expression. Furthermore, the roles of miR-21 in cell growth and invasion were analyzed with miR-21 inhibitor-transfected cells. miR-21 was overexpressed in tumor tissues relative to adjacent non-tumor tissues. Notably, patients with advanced clinical TNM stage (n=16) or distal metastasis (n=5) demonstrated higher miR-21 expression than those without them (n=26, or n=37) (p<0.05, or p<0.001). Tumor tissues showed an inverse correlation between miR-21 and PTEN protein. miR-21 inhibitor transfection increased a luciferase-reporter activity containing the PTEN-3'-UTR construct and increased PTEN protein but not PTEN-mRNA levels in NSCLC cell lines. Finally, miR-21 inhibitor-transfected cells exhibited markedly reduced cell growth and invasive characteristics. miR-21 post-transcriptionally down-regulates the expression of tumor suppressor PTEN and stimulates growth and invasion in NSCLC. It may be a potential therapeutic target for NSCLC.

MicroRNA alterations in head and neck squamous cell carcinoma

MicroRNAs (mirs) are small noncoding RNA molecules (~22 nucleotides) that regulate posttranscriptional gene expression. Currently, there has not been a comprehensive study of their role in primary head and neck squamous cell carcinoma (HNSCC). To determine the role of mirs in HNSCC, we screened for altered microRNA expression in HNSCC primary tissue and cell lines. We then further tested the functional impact of alterations of specific mirs. An initial screening of 4 primary HNSCC, 4 normal mucosal controls and 4 HNSCC cell lines was analyzed for mature microRNA expression by microarray. Significance was determined using significance analysis of microarrays (SAM). Nine microRNAs were found by SAM to be upregulated or downregulated in tumor tissue including mir-21, let-7, 18, 29c, 142-3p, 155, 146b (overexpressed) and 494 (underexpressed). Mir-21 was validated by qRT-PCR. Functional validation by growth assays was performed, further validating mir-21. Transfection of mir-21 into JHU-011 and JHU-012 cell lines showed a 39% increase in cell growth at 72 hr relative to controls (p < 0.05). Transfection of the inhibitor into JHU-O12 cell lines showed a 92% decrease in cell growth relative to controls at 72 hr (p < 0.05). In addition, flow cytometry analysis of JHU-012 cells 48 hr after mir-21 inhibitor transfection showed a statistically significant increase in cytochrome c release and increased apoptosis. These differentially expressed microRNAs may be of interest as potential novel oncogenes and tumor suppressor genes in HNSCC. Mir-21 is a putative oncogenic microRNA in head and neck cancer.