LncRNA MAGI2-AS3 inhibits hepatocellular carcinoma cell proliferation and migration by targeting the miR-374b-5p/SMG1 signaling pathway

Long noncoding RNAs (lncRNAs) have been proven to play critical roles in cancer progression. Recently, lncRNA MAGI2-AS3 has been revealed to be a tumor suppressor and inhibit cell growth by targeting the Fas/FasL signalling pathway in breast cancer. However, the role and underlying mechanism of MAGI2-AS3 in hepatocellular carcinoma (HCC) remain largely unknown. In the current study, we found that MAGI2-AS3 expression is downregulated in HCC tissues and closely associated with some clinical characteristics (tumor size, lymph node metastasis, and TNM stage) and poor overall survival. Overexpression of MAGI2-AS3 inhibits HCC cell proliferation and migration in vitro, while impedes tumor growth in vivo accordantly. In addition, our data suggest that MAGI2-AS3 could function as an endogenous sponge of miR-374b-5p by directly binding to it and suppressing its expression. Furthermore, miR-374b-5p upregulation could restore the inhibitory effect of MAGI2-AS3 on HCC cells processes. Moreover, suppressor with morphogenetic effect on genitalia family member 1 (SMG1) is positively regulated by MAGI2-AS3 via absorbing miR-374b-5p in HCC cells. More important, SMG1 knockdown reverses the suppressive function of MAGI2-AS3 in HCC cell processes. Taken together, we reveal a functional MAGI2-AS3/miR-374b-5p/SMG1 axis that suppresses HCC progression, potently suggesting a new road for HCC treatment.     

Long noncoding RNA FOXD2-AS1 promotes glioma malignancy and tumorigenesis via targeting miR-185-5p/CCND2 axis

Glioma is the most aggressive malignant tumor in the adult central nervous system. Abnormal long noncoding RNA (lncRNA) FOXD2-AS1 expression was associated with tumor development. However, the possible role of FOXD2-AS1 in the progression of glioma is not known. In the present study, we used in vitro and in vivo assays to investigate the effect of abnormal expression of FOXD2-AS1 on glioma progression and to explore the mechanisms. FOXD2-AS1 was upregulated in glioma tissue, cells, and sphere subpopulation. Upregulation of FOXD2-AS1 was correlated with poor prognosis of glioma. Downregulation of FOXD2-AS1 decreased cell proliferation, migration, invasion, stemness, and epithelial-mesenchymal transition (EMT) in glioma cells and inhibited tumor growth in transplanted tumor. We also revealed that FOXD2-AS1 was mainly located in cytoplasm and microRNA (miR)-185-5p both targeted FOXD2-AS1 and CCND2 messenger RNA (mRNA) 3′-untranslated region (3′-UTR). miR-185-5p was downregulated in glioma tissue, cells, and sphere subpopulation. Downregulation of miR-185-5p was closely correlated with poor prognosis of glioma patients. In addition, miR-185-5p mimics decreased cell proliferation, migration, invasion, stemness, and EMT in glioma cells. CCND2 was upregulated in glioma tissue, cells, and sphere subpopulation. Upregulation of CCND2 was closely correlated with poor prognosis of glioma patients. CCND2 knockdown decreased cell proliferation, migration, invasion, and EMT in glioma cells. In glioma tissues, CCND2 expression was negatively associated with miR-185-5p, but positively correlated with FOXD2-AS1. FOXD2-AS1 knockdown and miR-185-5p mimics decreased CCND2 expression. Inhibition of miR-185-5p suppressed FOXD2-AS1 knockdown-induced decrease of CCND2 expression. Overexpression of CCND2 suppressed FOXD2-AS1 knockdown-induced inhibition of glioma malignancy. Taken together, our findings highlight the FOXD2-AS1/miR-185-5p/CCND2 axis in the glioma development.     

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.     

SUMOylation of IGF2BP2 promotes vasculogenic mimicry of glioma via regulating OIP5-AS1/miR-495-3p axis

Rationale: Glioma is the most common primary malignant tumor of human central nervous system, and its rich vascular characteristics make anti-angiogenic therapy become a therapeutic hotspot. However, the existence of glioma VM makes the anti-angiogenic therapy ineffective. SUMOylation is a post-translational modification that affects cell tumorigenicity by regulating the expression and activity of substrate proteins.Methods: The binding and modification of IGF2BP2 and SUMO1 were identified using Ni²⁺-NTA agarose bead pull-down assays, CO-IP and western blot; and in vitro SUMOylation assays combined with immunoprecipitation and immunofluorescence staining were performed to explore the detail affects and regulations of the SUMOylation on IGF2BP2. RT-PCR and western blot were used to detect the expression levels of IGF2BP2, OIP5-AS1, and miR-495-3p in glioma tissues and cell lines. CCK-8 assays, cell transwell assays, and three-dimensional cell culture methods were used for evaluating the function of IGF2BP2, OIP5-AS1, miR-495-3p, HIF1A and MMP14 in biological behaviors of glioma cells. Meantime, RIP and luciferase reporter assays were used for inquiring into the interactions among IGF2BP2, OIP5-AS1, miR-495-3p, HIF1A and MMP14. Eventually, the tumor xenografts in nude mice further as certained the effects of IGF2BP2 SUMOylation on glioma cells.Results: This study proved that IGF2BP2 mainly binds to SUMO1 and was SUMOylated at the lysine residues K497, K505 and K509 sites, which can be reduced by SENP1. SUMOylation increased IGF2BP2 protein expression and blocked its degradation through ubiquitin-proteasome pathway, thereby increasing its stability. The expressions of IGF2BP2 and OIP5-AS1 were up-regulated and the expression of miR-495-3p was down-regulated in both glioma tissues and cells. IGF2BP2 enhances the stability of OIP5-AS1, thereby increasing the binding of OIP5-AS1 to miR-495-3p, weakening the binding of miR-495-3p to the 3''UTR of HIF1A and MMP14 mRNA, and ultimately promoting the formation of VM in glioma.Conclusions: This study first revealed that SUMOylation of IGF2BP2 regulated OIP5-AS1/miR-495-3p axis to promote VM formation in glioma cells and xenografts growth in nude mice, providing a new idea for molecular targeted therapy of glioma.     

Silencing lncRNA DUXAP8 inhibits lung adenocarcinoma progression by targeting miR-26b-5p

Lung adenocarcinoma (LUAD), a common type of lung cancer, has become a popularly aggressive cancer. Long noncoding RNAs (lncRNAs) play a critical role in the pathogenesis of human cancers, while the function of double homeobox A pseudogene 8 (DUXAP8) in LUAD remains to be fully inquired. Therefore, our study was conducted to elucidate the DUXAP8 expression in LUAD and its mechanism on the biological features of LUAD cells. Loss-of-function experiments were performed to assess the function of DUXAP8 proliferation and apoptosis of H1975 and A549 cells. Functionally, silencing DUXAP8 inhibited proliferation and induced apoptosis of LUAD cells. Mechanistically, further correlation assay indicated a negative association between miR-26b-5p and DUXAP8 expression. Subsequently, we testified that DUXAP8 exerted its role in the progression and development of LUAD through targeting miR-26b-5p. In summary, our results elucidated that that DUXAP8 promoted tumor progression in LUAD by targeting miR-26b-5p, which provide a novel therapeutic target for diagnosis and therapy of LUAD.     

LncRNA PDCD4-AS1 alleviates triple negative breast cancer by increasing expression of IQGAP2 via miR-10b-5p

ObjectiveMounting evidence demonstrates that long non-coding RNA (lncRNA) is dysregulated in breast cancers. This study was designed to detect the influences and regulatory mechanism of lncRNA PDCD4-AS1 in triple-negative breast cancer (TNBC).MethodsqRT-PCR and Western blot were utilized to investigate the expression levels of PDCD4-AS1, miR-10b-5p and IQGAP2 in TNBC tissues and cells. Online software and luciferase reporter gene system were employed to testify the interactions among these molecules. Loss and gain of function of PDCD4-AS1, miR-10b-5p or IQGAP2 were performed before MTT and colony formation assay, TUNEL staining in addition to Transwell and scratch assays were applied to measure the cell biological functions.ResultsIn this work, PDCD4-AS1 and IQGAP2 were lowly expressed while miR-10b-5p was strongly expressed in TNBC tissues and cells. PDCD4-AS1 or IQGAP2 overexpression effectively attenuated TNBC cell proliferation, migration and invasion, and increased the apoptosis rate, while this effect was abandoned in response to miR-10b-5p mimics transfection. miR-10b-5p bound to IQGAP2 and acted as a downstream target of PDCD4-AS1.ConclusionOur findings identified lncRNA PDCD4-AS1 as a tumor suppressor in TNBC by regulating IQGAP2 expression via miR-10b-5p, giving a novel insight into the regulatory mechanism of PDCD4-AS1 in the pathogenesis of TNBC.     

Long noncoding RNA DLGAP1-AS1 promotes cell proliferation in hepatocellular carcinoma via sequestering miR-486-5p

Hepatocellular carcinoma (HCC) is most prevalent tumor in liver and one of the most fatal cancers in the world. Long noncoding RNAs (lncRNAs) have been accepted as important regulators in carcinomas. But there are still many lncRNAs including DLGAP1-AS1 unannotated in HCC. First of all, GEPIA suggested that DLGAP1-AS1 presented high expression in HCC tissue samples relative to the normal tissues. Besides, overexpression of DLGAP1-AS1 was also proved in HCC cell lines. Moreover, DLGAP1-AS1 knockdown efficiently suppressed cell proliferation in HCC. Interestingly, miR-486-5p was predicted and validated to interact with DLGAP1-AS1, while the level of miR-486-5p was significantly increased In HCC after DLGAP1-AS1 knockdown. Moreover, we uncovered that ectopic expression of miR-486-5p induced suppression on HCC cell proliferation and that miR-486-5p inhibition offset the effect of DLGAP1-AS1 silence on HCC cell proliferation and apoptosis. Furthermore, H3F3B was identified as target of miR-486-5p and was therefore positively regulated by DLGAP1-AS1 in HCC. Of note, H3F3B upregulation partly revived the declined cell proliferative capacity in response to DLGAP1-AS1 knockdown. To conclude, DLGAP1-AS1 exerted its oncogenic role in HCC via miR-486-5p/H3F3B axis. Our new findings provided novel theoretical basis for discovery of therapeutic targets of HCC.     

Long noncoding RNA SOX21-AS1 regulates the progression of triple-negative breast cancer through regulation of miR-520a-5p/ORMDL3 axis

Recently, long noncoding RNAs (lncRNAs) have been reported as a new kind of controllers about cancer processes in biology. In spite of the dysregulation of lncRNAs in various kinds of cancers, only a little of the information was effective on the expression configuration and inner effects of lncRNAs in triple-negative breast cancer (TNBC). This study valued the expression of lncRNA SOX21-AS1 and the biological role it played in TNBC. In our research, SOX21-AS1 had a high expression in TNBC cell lines. The functional experiments showed that knockdown of SOX21-AS1 obviously restrained cell proliferation, migration, invasion, and epithelial-mesenchymal transition process and promoted cell apoptosis. Mechanistically, SOX21-AS1 was found to bind with miR-520a-5p. Besides, ORMDL3 was identified as a downstream target of miR-520a-5p, and the suppressed ORMDL3 expression induced by silenced SOX21-AS1 could be restored by miR-520a-5p inhibition. Further, data from rescue assays revealed that SOX21-AS1 could regulate the malignancy of TNBC via miR-520a-5p/ORMDL3 axis. All in all, we identified that SOX21-AS1 regulated the cellular process of TNBC cells via antagonizing miR-520a-5p availability to upregulate ORMDL3 expression.     

miR-216b-5p regulates proliferation and apoptosis of ox-LDL-stimulated VSMCs and HUVECs via IGF2

Atherosclerosis (AS) is one of the principal causes of cardiovascular disorder. Reportedly, vascular smooth muscle cells (VSMCs) and human umbilical vein endothelial cells (HUVECs) play key roles in AS development, and microRNAs (miRNAs) regulate their functions. The function of miR-216b-5p in AS remains unknown. Human VSMCs and human HUVECs were treated with ox-LDL to establish the in vitro model of AS. MiR-216b-5p and IGF2 expressions in VSMCs and HUVECs were probed by qRT-PCR and western blot. The viability, cell cycle progression, and apoptosis of VSMCs and HUVECs were evaluated by Cell Counting Kit-8 (CCK-8), 5-ethynyl-2′-deoxyuridine, and flow cytometry assays, respectively. The binding sites between IGF2 3′UTR and miR-216b-5p were validated by dual-luciferase reporter assay. miR-216b-5p expression was declined in ox-LDL-induced VSMCs and HUVECs. In VSMCs, miR-216b-5p overexpression inhibited excessive proliferation and induced apoptosis. MiR-216b-5p could markedly restrain the viabiblity of VSMCs induced by ox-LDL and enhanced the viability of HUVECs. Additionally, IGF2 was confirmed as the direct target of miR-216b-5p and transfection of IGF2 overexpression plasmids rescued the effects of miR-216b-5p on VSMCs and HUVECs. miR-216b-5p alleviates the dysfunction of VSMCs and HUVECs caused by ox-LDL via repressing IGF2, and exerts protective functions to block the development of AS.     

lncRNA RBM5-AS1 promotes cell proliferation and invasion by epigenetically silencing miR-132/212 in hepatocellular carcinoma cells

Hepatocellular carcinoma (HCC) is regarded as one of the most common malignancies worldwide leading to cancer-related death. Long noncoding RNAs (lncRNAs) are a critical modulator affecting HCC progression. Whereas, the pathogenesis of lncRNA RBM5-AS1 in the development of HCC remains unclear. Quantitative RT-PCR or western blot assays were applied to detect the expression of genes and proteins, respectively. The proliferation and metastasis abilities were assessed using Cell counting kit-8 (CCK-8), EdU and transwell assays. RNA immunoprecipitation (RIP) experiment was employed to validate the molecular interactions. RBM5-AS1 is highly expressed in HCC tissues and cell lines, especially in Hep3B and HepG2 cells. RBM5-AS1 knockdown dramatically restrains cell proliferation, invasion and migration of HCC cells. Importantly, RBM5-AS1 acts as an epigenetic regulator to elevate the H3K27me3 level of miR-132/212 promoter regions via recruiting PRC2 (EZH2, SUZ12, EED), and eventually reducing miR-132/212 expressions. The recovery experiments demonstrated that downregulation of miR-132/212 markedly eliminate the antitumor effects mediated by RBM5-AS1 silencing in HCC cells. The data of this work illustrate that RBM5-AS1 acts as an epigenetic regulator to promote the HCC progression by repressing miR-132/212 expressions, which would provide a new insight for understanding the action mechanism of RBM5-AS1 in HCC development.     

Long noncoding RNA FLVCR1-AS1 aggravates biological behaviors of glioma cells via targeting miR-4731-5p/E2F2 axis

Long noncoding RNAs (lncRNAs) display essential roles in cancer progression. FLVCR1-AS1 is a rarely investigated lncRNAs involved in various human cancers, such as hepatocellular carcinoma and lung cancer. However, its function in glioma has not been clarified. In our study, we found that FLVCR1-AS1 was highly expressed in glioma tissues and cell lines. And upregulation of FLVCR1-AS1 predicted poor prognosis in patients with glioma. Moreover, FLVCR1-AS1 knockdown inhibited proliferation, migration and invasion of glioma cells. Through bioinformatics analysis, we identified that FLVCR1-AS1 was a sponge for miR-4731-5p to upregulate E2F2 expression. Moreover, rescue assays indicated that FLVCR1-AS1 modulated E2F2 expression to participate in glioma progression. Altogether, our research demonstrates that the FLVCR1-AS1/miR-4731-5p/E2F2 axis is a novel signaling in glioma and may be a potential target for tumor therapy.     

LncRNA COL1A2-AS1 inhibits the scar fibroblasts proliferation via regulating miR-21/Smad7 pathway

lncRNA COL1A2-AS1 (COL1A2 antisense RNA 1), a lncRNA overexpressed in hypertrophic scar, has been demonstrated to be involved in the hypertrophic scar formation. However, the mechanisms of lncRNA COL1A2-AS1 inhibiting the scar fibroblasts proliferation remains not well understood. In this study, we demonstrated that lncRNA COL1A2-AS1 was upregulated in hypertrophic scar tissue and fibroblasts, and suppressed fibroblasts proliferation by promoting Smad7 expression. Furthermore, we found that miR-21 was involved in lncRNA COL1A2-AS1-induced expression of Smad7, by which COL1A2-AS1 acted as endogenous sponge to adsorb miR-21 and in turn regulated Smad7 and a cascade of molecular to play a protective role in hypertrophic scar. In addition, overexpression of miR-21 attenuated COL1A2-AS1-mediated proliferation suppression of hypertrophic scar fibroblasts. In conclusion, our study demonstrated that COL1A2-AS1/miR-21/Smad pathway plays an important role in inhibiting hypertrophic scar formation, and suggested this novel pathway may be a new target for hypertrophic scar treatment.     

Long noncoding RNA POU6F2-AS1 regulates lung cancer aggressiveness through sponging miR-34c-5p to modulate KCNJ4 expression

It has been extensively reported that long noncoding RNAs (lncRNAs) were closely associated with multiple malignancies. The aim of our study was to investigate the effects and mechanism of lncRNA POU6F2-AS1 in lung adenocarcinoma (LADC).The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) datasets provided us the information of LADC clinical samples. High-regulation of POU6F2-AS1 was presented in LADC tissues compared with adjacent normal tissues, which was correlated with poor outcome of LADC patients. Functional experiments in Calu-3 and NCI-H460 cells showed that POU6F2-AS1 significantly promoted LADC cell proliferation, colony formation, invasion and migration. Moreover, through online prediction, luciferase reporter assay and Pearson’s correlation analysis, we found that POU6F2-AS1 may act as a competing endogenous RNA (ceRNA) of miR-34c-5p and facilitated the expression of potassium voltage-gated channel subfamily J member 4 (KCNJ4). The promoting effect of cell aggressiveness induced by POU6F2-AS1 was enhanced by KCNJ4, whilst was abrogated due to the overexpression of miR-34c-5p. Collectively, POU6F2-AS1 might function as a ceRNA through sponging miR-34c-5p to high-regulate KCNJ4 in LADC, which indicates that POU6F2-AS1 might be a promising therapeutic target with significant prognostic value for LADC treatment.