Fibronectin-1 modulated by the long noncoding RNA OIP5-AS1/miR-200b-3p axis contributes to doxorubicin resistance of osteosarcoma cells

Chemoresistance has been an obstacle in the further improvement of 5-year survival rates of osteosarcoma (OS) patients, but the underlying mechanism of chemo-resistance remains unclear. A comprehensive analysis of mRNAs and noncoding RNAs related to OS chemo-resistance could help solve this problem. In the current study, we first identified that fibronectin-1 (FN1), screened by microarray analysis in three paired chemo-resistant and chemo-sensitive OS cell lines, was significantly upregulated in the chemo-resistant OS cell lines and tissues and was related to unfavourable prognosis. Further functional assays revealed that FN1 inhibition greatly increased the sensitivity of OS cells to doxorubicin in vitro and in vivo, whereas FN1 overexpression had the opposite effect. Moreover, mechanistic investigation demonstrated, by a series of assays that included luciferase reporter gene, RNA immunoprecipitation, RNA pull-down and rescue assays, that FN1 expression was regulated by the oncogenic long noncoding RNA (lncRNA) OIP5-AS1 through sponging miR-200b-3p. Thus, these results indicated the role and potential application of the lncRNA OIP5-AS1/miR-200b-3p/FN1 regulatory pathway as a promising target in treatment of OS chemo-resistance.     

Role of MicroRNA 1207-5P and Its Host Gene,the Long Non-Coding RNA Pvt1, as Mediators of Extracellular Matrix Accumulation in the Kidney: Implications for Diabetic Nephropathy

Diabetic nephropathy is the most common cause of chronic kidney failure and end-stage renal disease in the Western World. One of the major characteristics of this disease is the excessive accumulation of extracellular matrix (ECM) in the kidney glomeruli. While both environmental and genetic determinants are recognized for their role in the development of diabetic nephropathy, epigenetic factors, such as DNA methylation, long non-coding RNAs, and microRNAs, have also recently been found to underlie some of the biological mechanisms, including ECM accumulation, leading to the disease. We previously found that a long non-coding RNA, the plasmacytoma variant translocation 1 (PVT1), increases plasminogen activator inhibitor 1 (PAI-1) and transforming growth factor beta 1 (TGF-β1) in mesangial cells, the two main contributors to ECM accumulation in the glomeruli under hyperglycemic conditions, as well as fibronectin 1 (FN1), a major ECM component. Here, we report that miR-1207-5p, a PVT1-derived microRNA, is abundantly expressed in kidney cells, and is upregulated by glucose and TGF-β1. We also found that like PVT1, miR-1207-5p increases expression of TGF-β1, PAI-1, and FN1 but in a manner that is independent of its host gene. In addition, regulation of miR-1207-5p expression by glucose and TGFβ1 is independent of PVT1. These results provide evidence supporting important roles for miR-1207-5p and its host gene in the complex pathogenesis of diabetic nephropathy.     

Circ_0101692 knockdown retards the development of clear cell renal cell carcinoma through miR-384/FN1 pathway

PurposeCircular RNA_0101692 (circ_0101692) is overexpressed in clear cell renal cell carcinoma (ccRCC) by microarray analyses. However, its function and action mechanism in ccRCC tumorigenesis is still elusive.MethodsWestern blotting and qRT-PCR were executed to assess the circ_0101692, miR-384 and FN1 expression in ccRCC cells and tissues. Target relationships among them were determined via dual luciferase reporter and/or RNA immunoprecipitation assays. Cell proliferation was evaluated by CCK-8 assay. Caspase-3 activity assay was utilized to analyze cell apoptosis. To find out whether ccRCC cells might migrate, a transwell assay was performed. To assess the effects of circ_0101692 on tumor development in vivo, a mouse xenograft model was used.ResultsHigh expression of circ_0101692 and FN1, and decreased miR-384 were determined in ccRCC. Cell growth, migration and viability were decreased whereas cell apoptosis was stimulated when circ_0101692 was knockdown. miR-384 inhibitor transfection attenuated the inhibiting impacts of circ_0101692 silencing on ccRCC cell progression. FN1 deletion further inverted the cancer-promoting effect of miR-384 downregulation on cell viability and migration. In addition, circ_0101692 could sponge miR-384 to relieve the inhibition of miR-384 on FN1 in ccRCC.ConclusionsCirc_0101692 targeted miR-384/FN1 axis to facilitate cell proliferation, migration and repress apoptosis, thereby accelerating the development of ccRCC. This points out that circ_0101692/miR-384/FN1 axis might be a prospective target implemented for the future treatment of ccRCC.     

miRNA-1 regulates endothelin-1 in diabetes

Aims

MicroRNAs (miRNAs) play important roles in several biological processes. In this study, we investigated the role of miR-1, an endothelin-1 (ET-1) targeting miRNA, in endothelial cells (ECs) and tissues of diabetic animals. ET-1 is known to be of pathogenetic significance in several chronic diabetic complications.

Main methods

PCR array was used to identify alterations of miRNA expression in ECs exposed to glucose. miR-1 expression was validated by TaqMan real-time PCR assay. Human retinal ECs (HRECs) and human umbilical vein ECs (HUVECs) exposed to various glucose levels with or without miR-1 mimic transfection, and tissues from streptozotocin-induced diabetic animals after two months of follow-up, were examined for miR-1 expression, as well as ET-1 and fibronectin (FN) mRNA and protein levels.

Key findings

Array analyses showed glucose-induced alterations of 125 miRNAs (out of 381) in ECs exposed to 25 mM glucose compared to 5 mM glucose. Fifty-one miRNAs were upregulated and 74 were downregulated. 25 mM glucose decreased miR-1 expression and increased ET-1 mRNA and protein levels. miR-1 mimic transfection prevented HG-induced ET-1 upregulation. Furthermore, glucose induced upregulation of FN, which is mediated partly by ET-1, was also prevented by such transfection.Diabetic animals showed decreased miR-1 expression in the retina, heart and kidneys. In parallel, ET-1 mRNA expressions were increased in these tissues of diabetic animals, in association with upregulation of FN.

Significance

These results indicate a novel glucose-induced mechanism of tissue damage, in which miR-1 regulates ET-1 expressions in diabetes. Identifying such mechanisms may lead to RNA based treatment for diabetic complications.     

Effect of miR-21 on Renal Fibrosis by Regulating MMP-9 and TIMP1 in kk-ay Diabetic Nephropathy Mice

MicroRNAs (miRs) play important roles in initiation and progression of many pathologic processes. However, the roles of miRs in diabetic nephropathy remain unclear. This study was to determine whether miR-21 was involved in diabetic nephropathy and to explore the relationship between miR-21 and MMP9/TIMP1 expression in diabetic nephropathy. In situ hybridization studies showed that miR-21 was primarily localized and distributed in cortical glomerular and renal tubular cells in diabetic kk-ay kidney. Real-time quantitative RT-PCR demonstrated that the expression of miR-21 was significantly increased in kk-ay mice, compared with control C57BL mice. Interestingly, miR-21 expression positively correlated with urine albumin creatine ratio (ACR), TIMP1, collagen IV (ColIV), and fibronectin (FN); while negatively correlated with creatine clearance ratio (Ccr) and MMP-9 protein. Importantly, antagomir-21 not only ameliorated Ccr and ACR but also decreased TIMP1, ColIV, and FN proteins. In conclusion, our data demonstrate that miR-21 contributes to renal fibrosis by mediating MMP9/TIMP1 and that inhibition of miR-21 may be a novel target for diabetic nephropathy.     

MiR-23a Facilitates the Replication of HSV-1 through the Suppression of Interferon Regulatory Factor 1

MicroRNAs (miRNAs) are small, non-coding RNAs that negatively regulate gene expression. It has been reported that miRNAs are involved in host-virus interaction, but evidence that cellular miRNAs promote virus replication has been limited. Here, we found that miR-23a promoted the replication of human herpes simplex virus type 1 (HSV-1) in HeLa cells, as demonstrated by a plaque-formation assay and quantitative real-time PCR. Furthermore, interferon regulatory factor 1 (IRF1), an innate antiviral molecule, is targeted by miR-23a to facilitate viral replication. MiR-23a binds to the 3′UTR of IRF1 and down-regulates its expression. Suppression of IRF1 expression reduced RSAD2 gene expression, augmenting HSV-1 replication. Ectopic expression of IRF1 abrogated the promotion of HSV-1 replication induced by miR-23a. Notably, IRF1 contributes to innate antiviral immunity by binding to IRF-response elements to regulate the expression of interferon-stimulated genes (ISGs) and apoptosis, revealing a complex interaction between miR-23a and HSV-1. MiR-23a thus contributes to HSV-1 replication through the regulation of the IRF1-mediated antiviral signal pathway, which suggests that miR-23a may represent a promising target for antiviral treatments.     

miR-202 modulates the progression of neuropathic pain through targeting RAP1A

Neuropathic pain is a somatosensory disorder which is caused by disease or nerve injury that affects the nervous system. microRNAs (miRNAs) are proved to play crucial roles in the development of neuropathic pain. However, the role of miR-202 in neuropathic pain is still unknown. Sprague-Dawley rats were used for constructing the neuropathic pain model. The expression of miR-202 was determined by quantitative real-time polymerase chain reaction. Potential target gene for miR-202 was measured using bioinformatics methods and Western blot analysis. In this study, we used rats to establish a neuropathic pain model and measured the effect of miR-202 in neuropathic pain. We demonstrated that miR-202 expression was downregulated in the spinal dorsal horn of bilateral sciatic nerve chronic constriction injury (bCCI) rat. However, miR-202 expression was not changed in the dorsal root ganglion, hippocampus, and anterior cingulated cortex of bCCI rat. We identified that RAP1A was a direct target gene of miR-202 in the PC12 cell. RAP1A expression was upregulated in the spinal dorsal horn of bCCI rat. Overexpression of miR-202 could improve the pain threshold for bCCI rats in both hindpaws, indicating that miR-202 overexpression could lighten the pain threshold for model rats. Moreover, RAP1A overexpression increased the pain threshold effect of miR-202 overexpression treated bCCI rats, indicating that miR-202 could lighten the pain threshold through inhibiting RAP1A expression. These data suggested that miR-202 acted pivotal roles in the development of neuropathic pain partly through targeting RAP1A gene.     

miR-23b通过靶定TAB2/3抑制糖尿病肾病纤维化

MicroRNAs(miRNAs)通过与靶基因的相互作用发挥其生物学功能. miR-23b作为抑癌基因,参与了许多肿瘤和自身免疫疾病的发生过程,但其在糖尿病肾病中的作用尚不清楚.为了探讨miR-23b与靶基因TAB2/3作用对糖尿病肾病纤维化的影响,本实验通过建立糖尿病小鼠模型和糖尿病HK-2细胞模型,利用实时定量荧光PCR方法,检测糖尿病小鼠模型肾mRNA表达,发现miR-23b在糖尿病组（Dia组）表达低于正常组（P<0.001）.利用Western印迹检测相关蛋白,结果显示,与正常组相比,TAB2/3,FN和α-SMA在糖尿病组高表达,并且TAB2/3在糖尿病组中持续高表达.利用基因转染技术过表达miR-23b可以同时在mRNA和蛋白水平上抑制TAB2/3,P38和ERK1/2的表达,FN表达也显著降低.以上结果显示：miR-23b可能通过作用靶基因TAB2/3及其信号通路下游,抑制糖尿病肾病纤维化.     

MicroRNA-363-mediated downregulation of S1PR1 suppresses the proliferation of hepatocellular carcinoma cells

S1PR1 plays a crucial role in promoting proliferation of hepatocellular carcinoma (HCC). Over expression of S1PR1 is observed in HCC cell lines. The mechanisms underlying the aberrant expression of S1PR1 are not known well. MircroRNAs are important regulators of gene expression and disproportionate microRNAs can result in dysregulation of oncogenes in cancer cells. In this study, we found that miR-363, a potential tumor suppressor microRNA, downregulated the expression of S1PR1 and inhibited the proliferation of HCC cells. Bioinformatic analysis predicted a putative binding site of miR-363 within the 3′-UTR of S1PR1 mRNA. Luciferase reporter assay showed that miR-363 directly targeted the 3′-UTR of S1PR1 mRNA. Transfection of miR-363 mimics suppressed S1PR1 expression in HCC cells, followed by the repression of the activation of ERK and STAT3. Moreover, we found that the expression of downstream genes of ERK and STAT3, including PDGF-A, PDGF-B, MCL-1 and Bcl-xL, was suppressed after miR-363 transfection. Taken together, the present study demonstrated that miR-363 was a negative regulator of S1PR1 expression in HCC cells and inhibited cell proliferation, suggesting that the miR-363/S1PR1 pathway might be a novel target for the treatment of HCC.     

MiR-138 suppressed nasopharyngeal carcinoma growth and tumorigenesis by targeting the CCND1 oncogene

The microRNA miR-138 is dysregulated in several human cancers, but the underlying mechanism remains largely unknown. Here, we report that miR-138 is commonly underexpressed in nasopharyngeal carcinoma (NPC) specimens and NPC cell lines. The ectopic expression of miR-138 dramatically suppressed cell proliferation and colony formation in vitro and inhibited tumorigenesis in vivo. Moreover, we identified the cyclin D1 (CCND1) gene as a novel direct target of miR-138. In consistent with the knocked-down expression of CCND1, overexpression of miR-138 inhibited cell growth and cell cycle progression in NPC cells. Furthermore, CCND1 was widely upregulated in NPC tumors, and its mRNA levels were inversely correlated with miR-138 expression. Taken together, our findings suggest that miR-138 might be a tumor suppressor in NPC, which is exerted partially by inhibiting CCND1 expression. The identification of functional miR-138 in NPC and its direct link to CCND1 might provide good candidates for developing diagnostic markers and therapeutic applications for NPC.     

MicroRNA-638 inhibits cell proliferation by targeting phospholipase D1 in human gastric carcinoma

MicroRNAs (miRNAs) are a type of small non-coding RNAs that are often play important roles in carcinogenesis, but the carcinogenic mechanism of miRNAs is still unclear. This study will investigate the function and the mechanism of miR-638 in carcinoma (GC). The expression of miR-638 in GC and the DNA copy number of miR- 638 were detected by real-time PCR. The effect of miR-638 on cell proliferation was measured by counting kit-8 assay. Different assays, including bioinformatics algorithms (TargetScan and miRanda), luciferase report assay and Western blotting, were used to identify the target gene of miR-638 in GC. The expression of miR-638 target gene in clinical CRC tissues was also validated by immunohistochemical assay. From this research, we found that miR-638 was downregulated in GC tissues compared with corresponding noncancerous tissues (NCTs), and theDNAcopy numberof miR-638waslower in GC than NCTs, which may induce the corresponding downregulation of miR-638 in GC. Ectopic expression of miR-638 inhibited GC cell growth in vitro. Subsequently, we identified that PLD1 is the target gene of miR-638 in GC, and silencing PLD1 expression phenocopied the inhibitory effect of miR-638 on GC cell proliferation. Furthermore, we observed that PLD1 was overexpressed in GC tissues, and high expression of PLD1 in GC predicted poor overall survival. In summary, we revealed that miR- 638 functions as a tumor suppressor in GC through inhibiting PLD1.