Effect Of microRNA-206 Research Articles

Retraction.

Retraction: "Effects of microRNA-206 and its target gene IGF-1 on sevoflurane-induced activation of hippocampal astrocytes in aged rats through the PI3K/AKT/CREB signaling pathway," by Tie-Jun Liu, Bin Wang, Qun-Xi Li, Xiao- Liu Dong, Xiao-Liang Han, Shu-Bo Zhang, J Cell Physiol. 2018; 4294-4306: The above article, published online on 20 October 2017 in Wiley Online Library (https://onlinelibrary.wiley.com/doi/10.1002/jcp.26248) has been retracted by agreement between the journal's Editor in Chief, Prof. Dr. Gregg Fields, and Wiley Periodicals LLC. The retraction has been agreed following an investigation based on allegations raised by a third party. Several flaws and inconsistencies between results presented and experimental methods described were found. The editors consider the conclusions of this article to be invalid.

Retraction Statement.

Retraction Statement.

MiRNA-206 inhibits proliferation of renal clear cell carcinoma by targeting ZEB2.

The purpose of this study was to investigate the effect of microRNA-206 on the malignant progression of renal clear cell carcinoma (RCC). In addition, whether microRNA-206 could regulate ZEB2 expression and the underlying mechanisms was also explored. Quantitative Real Time-Polymerase Chain Reaction (qRT-PCR) was performed to examine microRNA-206 level in 46 tumor tissue specimens and adjacent ones of RCC patients. Also, the relationship between microRNA-206 expression and clinical indicators of RCC was analyzed. The negative control (NC) and microRNA-206 mimics were transfected into RCC cell lines, and the transfection efficiency was verified by qRT-PCR. The effects of microRNA-206 on the proliferation and apoptosis of RCC cells were analyzed by cell counting kit-8 (CCK-8), clone formation, and flow cytometry assays. Finally, the regulation of microRNA-206 on the downstream gene ZEB2 was indicated by Western Blot and cell recovery experiments. qRT-PCR results showed that the expression level of microRNA-206 in tumor tissue samples of RCC patients was remarkably lower than that in adjacent normal tissues, and the difference was statistically significant. Meanwhile, compared with patients with high expression of microRNA-206, the pathological stage of patients with low expression of microRNA-206 was higher, and the overall survival rate was lower. In the RCC cell lines (Caki-1 and Caki-2), the cell proliferation ability of the microRNA-206 overexpression group was remarkably weakened, while the cell apoptosis rate was oppositely enhanced when compared with the NC group. In addition, this study demonstrated that ZEB2 expression was remarkably increased in RCC cells as well as tissues and was negatively correlated with microRNA-206 expression. At the same time, microRNA-206 mimics was found remarkably reduced in the expression of proteins in ZEB2-related signaling pathway, including ZEB2, β-catenin, cyclinD1, c-Myc, MMP-2, and MMP-9. In the cell reverse experiment, the overexpression of ZEB2 was found to be able to counteract the impact of microRNA-206 mimics on RCC cell proliferation and apoptosis and thus, participated in the malignant progression of RCC. This study revealed that microRNA-206 was remarkably associated with the pathological stage and poor prognosis of RCC patients. In addition, microRNA-206 might inhibit the malignant progression of RCC by regulating the targeted ZEB2.

MiR‑206 regulates alveolar type�II epithelial cell Cx43 expression in sepsis‑induced acute lung injury

The present study investigated the relationship between connexin 43 (Cx43) expression in alveolar type II epithelial cells (ATII) and alveolar air-blood barrier permeability, and the effect of microRNA-206 (miR-206) on the expression of Cx43 in sepsis-induced acute lung injury. For the in vivo study, rats were divided into the sham, caecum ligation and perforation (CLP), CLP+Cx43 inhibitors (Cx43-In) and CLP+miR-206 analogs (miR-206-Mi) groups. CLP method was used to prepare an acute lung injury model of sepsis. Following successful modeling, lung tissue was collected for hematoxylin and eosin (HE) staining, and the wet to dry weight ratio (W/D) and protein content in bronchoalveolar lavage fluid (BALF) were detected. Cx43 expression in lung tissue was determined by immunohistochemistry and western blot analysis. Additionally, miR-206 and Cx43 expression levels in lung tissue were detected by reverse transcription-quantitative polymerase chain reaction. Rat ATII cells were cultured in Transwells plates to form monolayers, then treated with Cx43 mRNA inhibitors or miR-206 analogs. The cell monolayers were then stimulated with lipopolysaccharide and their permeability was evaluated by detecting fluorescein-labeled dextran at the lower chamber of the Transwells. The dual luciferase reporter gene assay was used to investigate whether miR-206 targeted the 3′ untranslated region of Cx43 mRNA to regulate Cx43 expression, thereby regulating the permeability of the alveolar air-blood barrier. Results demonstrated that the CLP method induced damage to the alveolar structure, thickened the alveolar wall, caused hyperemia and hemorrhage in the pulmonary interstitium and caused infiltration of inflammatory cells. Edema in the pulmonary interstitium and alveolar space, exudation of neutrophilic granulocyte and pink edema fluid in alveolar cavities were also observed. W/D ratio, the BALF protein content, and expression of Cx43mRNA and Cx43 were increased significantly, whilst miR-206 expression decreased compared with the control group. The lung tissue inflammatory response was attenuated, and the W/D ratio and BALF protein content decreased in the Cx43-In and miR-206-Mi groups compared with the CLP group. Moreover, Cx43 mRNA and protein expression were decreased significantly in the Cx43-In and miR-206-Mi groups. In addition, the dual luciferase reporter gene assay determined that the untranslated region of Cx43 mRNA had a complementary sequence to miR-206. Of note, Cx43 mRNA expression in the miR-206-Mi group was not significantly decreased in vitro. In conclusion, the increase in ATII cell Cx43 expression during sepsis-induced acute lung injury resulted in an increase in the permeability of the alveolar air-blood barrier. miR-206 targeted the Cx43 mRNA 3′untranslated region to downregulate Cx43 expression, which further improved the permeability of the alveolar air-blood barrier.

Effect of microRNA-206 on cytoskeleton remodelling by downregulating Cdc42 in MDA-MB-231 cells.

MicroRNAs are small, noncoding, single-stranded RNAs that regulate gene expression post-transcriptionally. miR-206 is known to play an important role in breast cancer metastasis. When we sought to predict the target of miR-206 by Targetscan, Pictar and miRanda, we found Cdc42 was a potential one. In this study, we transfected miR-206 into MDA-MB-231 cells and examined Cdc42 protein expression as well as MMP-2 and MMP-9, which are also associated with metastasis of breast cancer. Since Cdc42 is involved in filopodia and invadopodia formation, we examined the morphological changes of MDA-MB-231 cells. miR-206 mimics were transfected into MDA-MB-231 cells using LipofectamineTM 2000. Protein expression was detected by Western blot. Cells were stained with FITC-phalloidin to visualize F-actin. Invasive ability and migratory ability were examined by invasion assay and migration assay in vitro. Cdc42, MMP-2 and MMP-9 were downregulated on the protein level. The formation of filopodia, which requires Cdc42, was inhibited in miR-206 transfected cells, even under the stimulation of EGF. The invasion and migration of MDA-MB-231 cells in vitro was inhibited by miR-206 too. The results suggest that miR-206 may suppress invasion and migration of MDA-MB-231 cells in vitro partly via regulating actin cytoskeleton remodelling such as filopodia formation.

Effects of MicroRNA-206 on Osteosarcoma Cell Proliferation, Apoptosis, Migration and Invasion by Targeting ANXA2 Through the AKT Signaling Pathway

This study aimed to investigate the mechanism by which microRNA-206 (miR-206) affects the proliferation, apoptosis, migration and invasion of osteosarcoma (OS) cells by targeting ANXA2 via the AKT signaling pathway. A total of 132 OS tissues and 120 osteochondroma tissues were examined in this study. The targeting relationship between miR-206 and ANXA2 was verified with a dual-luciferase reporter assay. The miR-206 expression and ANXA2, AKT, PARP, FASN, Survivin, Bax, Mcl-1 and Bcl-1 mRNA and protein expression in the above two groups were examined by qRT-PCR and western blotting. The cultured OS cells were divided into 6 groups: a blank group, negative control (NC) group, miR-206 mimic group, miR-206 inhibitor group, si-ANXA2 group and miR-206 inhibitor + si-ANXA2 group. Cell cycle and apoptosis were assessed by flow cytometry, cell migration was examined with a wound-healing assay, and cell invasion was assessed with a Transwell assay. Pearson correlation analysis was used to determine the correlation between ANXA2 mRNA expression and miR-206 expression in OS. OS tissues exhibited increased mRNA and protein expression of ANXA2, AKT, PARP, FASN, Survivin, Mcl-1 and Bcl-2; decreased miR-206 expression; and decreased Bax mRNA and protein expression. ANXA2 mRNA expression was strongly negatively correlated with miR-206 expression in OS. ANXA2 was found to be a miR-206 target gene. In the miR-206 mimic group and the si-ANXA2 group, the mRNA and protein expression of ANXA2, AKT, PARP, FASN, Survivin, Mcl-1 and Bcl-1 decreased markedly, cell proliferation was inhibited, apoptosis was promoted, higher cell growth in G1 phase and decreased growth in S phase was detected, and decreased cell migration and invasion were observed compared with those in the blank group. The current results demonstrate that miR-206 overexpression inhibits OS cell proliferation, migration and invasion and promotes apoptosis through targeting ANXA2 by blocking the AKT signaling pathway.

Effect of microRNA-206 on the growth of prostate cancer cells by interfering with the expression of CDK4 and GAK

Objective To investigate the effect of microRN-206 (miR-206) on the expression of Cyclin-dependent kinase 4 (CDK4) and Cyclin G-associated protein kinase (GAK), and the growth of prostate cancer cells. Methods Prostate cancer cell lines DU-145 and PC-3 were transfected with miR-NC (the control group) or miR-206 (the experimental group). The expressions of CDK4 and GAK mRNA were detected by real-time quantitative PCR (qRT-PCR). The expressions of CDK4 and GAK protein were detected by Western blotting. Cell cycle distribution was detected by flow cytometry. EdU proliferation assay and colony forming assay were used to analyze the cell proliferation ability. Results In DU-145 and PC-3 cells, the expressions of CDK4 mRNA in miR-NC group were 1.00±0.09, 1.00±0.10, the expressions of GAK mRNA were 1.00±0.05, 1.00±0.06. The expressions of CDK4 mRNA in miR-206 group were significantly decreased in DU-145 (0.36±0.18; t=6.572, P=0.001) and PC-3 cell lines (0.43±0.17; t=5.794, P=0.001). The expressions of GAK mRNA were also significantly decreased in DU-145 (0.23±0.04; t=22.420, P<0.001) and PC-3 cell lines (0.32±0.08; t=14.500, P<0.001). Western blotting results were consistent with qRT-PCR results. The results of flow cytometry showed that compared with the miR-NC group of DU-145 and PC-3 cell lines, the percentage of cells in S phase (23.60%±5.68% vs. 32.53%±4.52%, t=2.462, P=0.049; 22.09%±4.35% vs. 30.96%±4.86%, t=2.720, P=0.035) and G2-M phase (16.28%±7.12% vs. 26.63%±4.33%, t=2.484, P=0.048; 14.60%±1.62% vs. 24.68%±7.13%, t=2.758, P=0.033) decreased after transfection of miR-206, and the percentage of cells in G0-G1 phase (60.13%±5.82% vs. 40.84%±5.37%, t=4.872, P=0.003; 63.31%±3.27% vs. 44.36%±3.82%, t=7.533, P<0.001) increased. The results of EdU proliferation assay showed that the proliferation abilities were significantly attenuated after transfection of miR-206 (22.56±3.81 vs. 38.90±8.51, t=3.503, P=0.013; 25.12±6.42 vs. 48.45±8.92, t=4.244, P=0.005). The results of colony formation experiments showed that the numbers of colonies formed by DU-145 and PC-3 in miR-NC group were 218.66±44.59 and 177.35±24.49, respectively. The numbers of colonies formed in miR-206 group were 125.38±32.80 (t=3.370, P=0.015) and 82.65±14.05 (t=6.708, P=0.001), suggesting that cell proliferation ability in miR-206 group was reduced. Conclusion miR-206 significantly inhibits the growth of prostate cancer cells by interfering with the expressions of CDK4 and GAK, suggesting that miR-206 may be a molecular targeted therapy tool for prostate cancer. Key words: MicroRNAs; Prostatic neoplasms; Cell proliferation; Cyclin-dependent kinase 4; Cyclin G-associated protein kinase

Effect of microRNA-206 on G1 arrest by inhibition of CDK4, cyclin C, and cyclin D in melanoma cells.

e20047 Background: MiR-206 has been implicated in a large number of cancers. However, its role in tumor biology is unknown and its biological function has yet to be fully characterized. To examine the role of miR-206 in cancer, we examined the expression of miR-206 in melanoma and identified potential target transcriptss that could be important for the progression of this disease. Methods: Using quantitative RT-PCR we compared expression of 364 microRNAs in melanoma skin biopsies skin from normal donors, melanoma cell lines, and normal melanocytes. The effects of miR-206 on cell growth, apoptosis, and cellular migration/invasion were determined using in vitro assays comparing melanoma cell lines to normal melanocytes. Putative mRNA targets of miR-206 were bioinfomatically identified, and empirically tested by luciferase-3’UTR reporter assays. The effect of miR-206 on the cell cycle of melanoma cells was assayed by flow cytometry. Results: Expression profiling of microRNAs in melanoma lesional skin biopsies compared to normal donor skin biopsies revealed numerous differentially regulated miRs. One such microRNA, miR-206, was significantly highly down-regulated in melanoma biopsies (-75.4-fold, p=1.7x10-4) compared to normal skin and normal melanocytes. Functional analysis showed that miR-206 substantially reduced growth and migration/invasion of multiple melanoma cell lines. Bioinformatic analysis identified the cell cycle genes CDK2, CDK4, Cyclin C, and Cyclin D1 as strong candidate mRNA targets of miR-206. Luciferase reporter gene assays revealed that miR-206 inhibits translation of CDK4, Cyclin D1, and Cyclin C. Consistent with this inhibition of CDK4 and Cyclin D1, miR-206 transfection induced robust G1 arrest in multiple melanoma cell lines. Conclusions: MiR-206 expression was decreased in melanoma tissue and cell lines compared to normal skin and melanocytes, respectively. Inhibition of Cyclin C, Cyclin D1 and CDK4 by miR-206 highlights its role in regulating cell cycle progression, a key aspect of melanoma progression. These observations support miR-206 as a potential tumor suppressor in melanoma, and possibly other cancers.

Effect of microRNA-206 on Cytoskeleton Remodelling by Downregulating Cdc42 in MDA-MB-231 Cells

MicroRNAs are small, noncoding, single-stranded RNAs that regulate gene expression post-transcriptionally. miR-206 is known to play an important role in breast cancer metastasis. When we sought to predict the target of miR-206 by Targetscan, Pictar and miRanda, we found Cdc42 was a potential one. In this study, we transfected miR-206 into MDA-MB-231 cells and examined Cdc42 protein expression as well as MMP-2 and MMP-9, which are also associated with metastasis of breast cancer. Since Cdc42 is involved in filopodia and invadopodia formation, we examined the morphological changes of MDA-MB-231 cells. miR-206 mimics were transfected into MDA-MB-231 cells using LipofectamineTM 2000. Protein expression was detected by Western blot. Cells were stained with FITC-phalloidin to visualize F-actin. Invasive ability and migratory ability were examined by invasion assay and migration assay in vitro. Cdc42, MMP-2 and MMP-9 were downregulated on the protein level. The formation of filopodia, which requires Cdc42, was inhibited in miR-206 transfected cells, even under the stimulation of EGF. The invasion and migration of MDA-MB-231 cells in vitro was inhibited by miR-206 too. The results suggest that miR-206 may suppress invasion and migration of MDA-MB-231 cells in vitro partly via regulating actin cytoskeleton remodelling such as filopodia formation.