Long noncoding RNA SBF2-AS1 act as a ceRNA to modulate cell proliferation via binding with miR-188-5p in acute myeloid leukemia

The role of CEMIP in cancers and its transcriptional and post-transcriptional regulation

CEMIP is a protein known for inducing cell migration and binding to hyaluronic acid. Functioning as a hyaluronidase, CEMIP primarily facilitates the breakdown of the extracellular matrix component, hyaluronic acid, thereby regulating various signaling pathways. Recent evidence has highlighted the significant role of CEMIP in different cancers, associating it with diverse pathological states. While identified as a biomarker for several diseases, CEMIP's mechanism in cancer seems distinct. Accumulating data suggests that CEMIP expression is triggered by chemical modifications to itself and other influencing factors. Transcriptionally, chemical alterations to the CEMIP promoter and involvement of transcription factors such as AP-1, HIF, and NF-κB regulate CEMIP levels. Similarly, specific miRNAs have been found to post-transcriptionally regulate CEMIP. This review provides a comprehensive summary of CEMIP's role in various cancers and explores how both transcriptional and post-transcriptional mechanisms control its expression.

Identification of immunity-related lncRNAs and construction of a ceRNA network of potential prognostic biomarkers in acute myeloid leukemia

Objective: Using bioinformatics analyses, this study aimed to identify lncRNAs related to the immune status of acute myeloid leukemia (AML) patients and ascertain the potential impact in immunity-related competing endogenous RNA (ceRNA) networks on AML prognosis. Methods: AML-related RNA-seq FPKM data, AML-related miRNA expression microarray data, and gene sets associated with immunity-related pathways were, respectively, obtained from the TCGA, GEO, and ImmReg databases. An immunity-related ceRNA network was then constructed according to the predicted interactions between AML-related mRNAs, lncRNAs, and miRNAs. After performing LASSO and multivariate Cox regression analyses, lncRNAs in the ceRNA network were used to establish an AML prognostic model. According to mutual regulatory relationships and consistent trends of expression among candidate ceRNAs, two ceRNA subnetworks related to the AML prognostic model were determined. Finally, the correlation between the expression levels of mRNAs, lncRNAs, and miRNAs in each ceRNA subnetwork and immune cell infiltration (assessed by combining the ESTIMATE and CIBERSORT methods and ssGSEA) was analyzed. Results: A total of 424 immunity-related differentially expressed (IR-DE) mRNAs (IR-DEmRNAs), 191 IR-DElncRNAs, and 69 IR-DEmiRNAs were obtained, and a ceRNA network of 20 IR-DElncRNAs, 6 IR-DEmRNAs, and 3 IR-DEmiRNAs was established. Univariate Cox regression analysis was conducted on 20 IR-DElncRNAs, and 7 of these were identified to be significantly correlated with the overall survival (OS) time in AML patients. Then, two IR-DElncRNAs (MEG3 and HCP5) were screened as independent OS-related factors by LASSO and multivariable Cox regression analyses, and a prognostic model was constructed to evaluate the survival risk in AML patients. Survival analyses indicated that the OS of patients was often poor in the high-risk group. Additionally, from this model, two ceRNA regulatory pathways, namely, MEG3/miR-125a-5p/SEMA4C and HCP5/miR-125b-5p/IL6R, which were potentially involved in the immune regulation of AML prognosis were identified. Conclusion: lncRNAs HCP5 and MEG3 may act as key ceRNAs in the pathogenesis in AML by regulating immune cell representation as part of the regulatory lncRNA-miRNA-mRNA axes. The candidate mRNAs, lncRNAs, and miRNAs included in the ceRNA network identified here may serve as useful prognostic biomarkers and immunotherapeutic targets for AML.

TET1-mediated microRNA-188-5p promoter hydroxymethylation regulates PTEN/PI3K/AKT signaling pathway in acute myeloid leukemia cells

OBJECTIVE

Acute myeloid leukemia (AML) remains a common hematopoietic malignancy, and drug resistance greatly blunts the efficacy of chemotherapy in AML treatment. Adriamycin (ADM, also called doxorubicin), is one of the most widely used chemotherapeutics for treating cancers. Herein, we studied the molecular mechanisms underlying microRNA-188-5p (miR-188-5p)-mediated ADM resistance in AML.

METHODS

Differentially expressed miRNAs were screened in normal and malignant hematopoietic cells by bioinformatics tools. MiR-188-5p expression in primary bone marrow CD34⁺ cells and AML cells was evaluated. AML/ADM cells were established using THP-1 and Kasumi-1 cells. The effect of miR-188-5p on the drug resistance in AML/ADM cells was examined by delivery of miR-188-5p-inhibitor. The binding relationship between TET1 and miR-188-5p was analyzed by ChIP, and the downstream target of miR-188-5p was predicted by bioinformatics analysis and validated by dual-luciferase assay. Finally, rescue experiments were carried out in vitro and in vivo.

RESULTS

miR-188-5p was highly expressed in AML cells, and miR-188-5p-inhibitor sensitized the AML/ADM cells to ADM. Inhibition of TET1 reduced miR-188-5p promoter hydroxymethylation and downregulated miR-188-5p. miR-188-5p bound to the 3'UTR of PTEN to inhibit PTEN expression, and the PI3K/AKT signaling was activated upon inhibition of PTEN. Suppression of PTEN conferred resistance again to AML/ADM cells in the presence of miR-188-5p inhibitor.

CONCLUSION

TET1 elevates miR-188-5p expression by promoting miR-188-5p promoter hydroxymethylation, and miR-188-5p inhibits PTEN expression to induce PI3K/AKT signaling pathway activation, leading to ADM resistance in AML.

LncRNA MAFG-AS1-induced acute myeloid leukemia development via modulating miR-147b/HOXA9

Recent references discovered that lncRNAs acted roles in malignant cancer development. However, the role of MAFG-AS1 in acute myeloid leukemia (AML) development remains unknown. MAFG-AS1 and miR-147b were determined in AML cells and specimens using qRT-PCR assay. Cell proliferation was detected by CCK-8 analysis and flow cytometry was carried out to measure cell cycle. Luciferase reporter analysis was done to determine the mechanism of MAFG-AS1 and miR-147b. We noted that MAFG-AS1 was overexpressed in AML cells and in serum and bone narrow from AML compared with normal controls specimen. Elevated expression of MAFG-AS1 increased cell growth, cycle and EMT in AML cell HL-60 cell. MAFG-AS1 sponged miR-147b expression in HL-60 cell. Moreover, miR-147b was downregulated in AML cells and in serum and bone narrow from AML compared with normal control specimen. miR-147b was negatively correlated with MAFG-AS1 in the serum and bone narrow of AML cases. We illustrated that HOXA9 was one target of miR-147b and ectopic expression of MAFG-AS1 enhanced HOXA9 expression HL-60 cell. Forced expression of MAFG-AS1 induced cell growth, cycle, and EMT via promoting HOXA9. These data illustrated that MAFG-AS1 acted as one oncogenic gene and accelerated AML progression via modulating miR-147b/HOXA9 axis.

Long non-coding RNA OGFRP1 regulates cell proliferation and ferroptosis by miR-299-3p/SLC38A1 axis in lung cancer

Lung cancer is devastating cancer that ranks as the leading cause of cancer-related death. Long noncoding RNA (lncRNA) opioid growth factor receptor pseudogene 1 (OGFRP1) was recognized as an oncogene in many cancers. However, the molecular mechanism of OGFRP1 in lung cancer is still poorly understood. The expression of target RNAs and genes was detected by quantitative real-time PCR and western blot. The interaction between miR-299-3p and OGFRP1 or solute carrier family 38 member 1 (SLC38A1) was predicted by StarbaseV3.0 and verified by dual-luciferase reporter assay and Pearson's correlation coefficient. Besides, a transplantation model of human lung cancer in nude mice was established to evaluate the role of OGFRP1 in lung cancer. OGFRP1 and SLC38A1 were overexpressed, whereas miR-299-3p was lowly expressed in lung cancer tumors and cells. OGFRP1 knockdown suppressed cell proliferation and facilitated ferroptosis by promoting lipid peroxidation and iron accumulation in lung cancer. Besides, Furthermore, miR-299-3p inhibitor or SLC38A1 overexpression attenuated OGFRP1 depletion-induced suppression on cell proliferation and ferroptosis in lung cancer. Animal experiments indicated that OGFRP1 deficiency restrained tumor growth in vivo by regulating the miR-299-3p/SLC38A1 axis. OGFRP1 regulated cell proliferation and ferroptosis in lung cancer by inhibiting miR-299-3p to enhance SLC38A1 expression, providing a novel therapeutic strategy for lung cancer.

LncRNA SBF2-AS1: A Budding Star in Various Cancers

Long non-coding RNA (lncRNA) is a new kind of RNA with lengths over 200 nucleotides. Current frontiers revealed that lncRNAs implicate in various tumor progression, including tumorigenesis, proliferation, migration, invasion, metastasis and angiogenesis. Recently discovered long non-coding RNA SET-binding factor 2 antisense RNA 1 (lncRNA SBF2-AS1), an oncogenic antisense RNA to SBF2, locates at 11p15.1 locus and is 2708 nt long. Accumulating evidences have demonstrated that lncRNA SBF2-AS1 participates in various tumor progression including pathogenesis, diagnosis, treatment and prognosis of acute myeloid leukemia (AML), breast cancer (BC), cervical cancer (CC), clear cell renal cell carcinoma (ccRCC), colorectal cancer (CRC), diffuse large B-cell lymphoma (DLBCL), esophageal squamous cell carcinoma (ESCC), gastric cancer (GC), glioma, glioblastoma (GBM), hepatocellular carcinoma (HCC), lung cancer (LC), lung adenocarcinoma (LUAD), non-small cell lung cancer (NSCLC), osteosarcoma (OS), pancreatic cancer (PC), papillary thyroid cancer (PTC), small cell lung cancer (SCLC). Therefore, we summarized the underlying mechanisms about lncRNA SBF2-AS1 in various cancers to utilize its therapeutic function in target-selective treatment modality.

Comprehensive Analysis of Potential Biomarkers of Acute Lymphoblastic Leukemia in Children by Using a Competing Endogenous RNA Network

Acute lymphoblastic leukemia (ALL) is the most serious hematological carcinoma in adolescents. The significance of long noncoding RNAs (lncRNAs) and their regulative role in the proliferation and differentiation of myeloid cells in cancer has been recently reported. Nevertheless, key RNAs and the regulatory mechanism of competitive endogenous RNA (ceRNA) network affected by pediatric ALL are not fully illustrated. In this study, phase 2 and 3 pediatric ALL RNA profiles were extracted from the TARGET database and used to identify lncRNAs, microRNAs, and messenger RNAs in high-risk ALL and reconstruct the sponge ceRNA regulatory network. Results indicated that 44 lncRNAs, 25 miRNAs, and 115 mRNA were up/downregulated. Functional analysis with differentially expressed RNAs (DERNAs) showed enriched significant signaling pathways, including PI3K-Akt and p53 signaling cascades and other pathways associated with the tumor. Seventeen differential hub RNAs, including LINC00909, BZRAP1-AS1, C17orf76-AS1, HCG11, MIAT, SNHG5, SNHG15, and TP73-AS1, were identified. The Cox model of correlation indicated that 14 of these RNAs were associated with the progression of pediatric ALL. These findings would help clarify the regulatory role of several lncRNAs as well as provide insights into the leukemogenesis of pediatric ALL to further explore novel prognostic markers/therapeutic targets for ALL.

Revealing key lncRNAs in cytogenetically normal acute myeloid leukemia by reconstruction of the lncRNA-miRNA-mRNA network

Cytogenetically normal acute myeloid leukemia (CN-AML) is a heterogeneous disease with different prognoses. Researches on prognostic biomarkers and therapy targets of CN-AML are still ongoing. Instead of protein-coding genes, more and more researches were focused on the non-coding RNAs especially long non-coding RNAs (lncRNAs) which may play an important role in the development of AML. Although a large number of lncRNAs have been found, our knowledge of their functions and pathological process is still in its infancy. The purpose of this research is to identify the key lncRNAs and explore their functions in CN-AML by reconstructing the lncRNA-miRNA-mRNA network based on the competitive endogenous RNA (ceRNA) theory. We reconstructed a global triple network based on the ceRNA theory using the data from National Center for Biotechnology Information Gene Expression Omnibus and published literature. According to the topological algorithm, we identified the key lncRNAs which had both the higher node degrees and the higher numbers of lncRNA-miRNA pairs and total pairs in the ceRNA network. Meanwhile, Gene Ontology (GO) and pathway analysis were performed using databases such as DAVID, KOBAS and Cytoscape plug-in ClueGO respectively. The lncRNA-miRNA-mRNA network was composed of 90 lncRNAs,33mRNAs,26 miRNAs and 259 edges in the lncRNA upregulated group, and 18 lncRNAs,11 mRNAs,6 miRNAs and 45 edges in the lncRNA downregulated group. The functional assay showed that 53 pathways and 108 GO terms were enriched. Three lncRNAs (XIST, TUG1, GABPB1-AS1) could possibly be selected as key lncRNAs which may play an important role in the development of CN-AML. Particularly, GABPB1-AS1 was highly expressed in CN-AML by both bioinformatic analysis and experimental verification in AML cell line (THP-1) with quantitative real-time polymerase chain reaction. In addition, GABPB1-AS1 was also negatively correlated with overall survival of AML patients. The lncRNA-miRNA-mRNA network revealed key lncRNAs and their functions in CN-AML. Particularly, lncRNA GABPB1-AS1 was firstly proposed in AML. We believe that GABPB1-AS1 is expected to become a candidate prognostic biomarker or a potential therapeutic target.

Identification of Potential Novel Prognosis-Related Genes Through Transcriptome Sequencing, Bioinformatics Analysis, and Clinical Validation in Acute Myeloid Leukemia

Background: Acute Myeloid Leukemia (AML) is a complex and heterogeneous hematologic malignancy. However, the function of prognosis-related signature genes in AML remains unclear. Methods: In the current study, transcriptome sequencing was performed on 15 clinical samples, differentially expressed RNAs were identified using R software. The potential interactions network was constructed by using the common genes between target genes of differentially expressed miRNAs with transcriptome sequencing results. Functional and pathway enrichment analysis was performed to identify candidate gene-mediated aberrant signaling pathways. Hub genes were identified by the cytohubba plugin in Cytoscape software, which then expanded the potential interactions regulatory module for hub genes. TCGA-LAML clinical data were used for the prognostic analysis of the hub genes in the regulatory network, and GVSA analysis was used to identify the immune signature of prognosis-related hub genes. qRT-PCR was used to verify the expression of hub genes in independent clinical samples. Results: We obtained 1,610 differentially expressed lncRNAs, 233 differentially expressed miRNAs, and 2,217 differentially expressed mRNAs from transcriptome sequencing. The potential interactions network is constructed by 12 lncRNAs, 25 miRNAs, and 692 mRNAs. Subsequently, a sub-network including 15 miRNAs as well as 12 lncRNAs was created based on the expanded regulatory modules of 25 key genes. The prognostic analysis results show that CCL5 and lncRNA UCA1 was a significant impact on the prognosis of AML. Besides, we found three potential interactions networks such as lncRNA UCA1/hsa-miR-16-5p/COL4A5, lncRNA UCA1/hsa-miR-16-5p/SPARC, and lncRNA SNORA27/hsa-miR-17-5p/CCL5 may play an important role in AML. Furthermore, the evaluation of the immune infiltration shows that CCL5 is positively correlated with various immune signatures, and lncRNA UCA1 is negatively correlated with the immune signatures. Finally, the result of qRT-PCR showed that CCL5 is down-regulated and lncRNA UCA1 is up-regulated in AML samples separately. Conclusions: In conclusion, we propose that CCL5 and lncRNA UCA1 could be recognized biomarkers for predicting survival prognosis based on constructing competing endogenous RNAs in AML, which will provide us novel insight into developing novel prognostic, diagnostic, and therapeutic for AML.

Potentiated lung adenocarcinoma (LUAD) cell growth, migration and invasion by lncRNA DARS-AS1 via miR-188-5p/ KLF12 axis

Lung adenocarcinoma (LUAD) is the most common histological type of non-small cell lung cancer (NSCLC). Due to the nonspecific early symptoms, the majority of the diagnosed LUAD patients are in the middle and late stages, with multiple metastases, and have missed the optimal period for treatment. Current studies have reported lncRNA DARS-AS1 as a cancer-promoting gene that expedites tumorigenesis. This is the first study demonstrating that DARS-AS1 is involved in the mediating process of LUAD. Cell functional experiments revealed that lncRNA DARS-AS1 participated in enhancing LUAD proliferation, invasion, and migration by inhibiting miR-188-5p. The investigation on DARS-AS1/miR-188-5p led to the discovery of KLF12 as a downstream target of miR-188-5p, and the regulatory pathway was established as DARS-AS1/miR-188-5p/KLF12. According to western blot results, DARS-AS1 promoted LUAD cell growth, migration, and invasion via stimulation of the PI3K/AKT pathway, activating the EMT process, and up-regulating the CyclinD1 and Bcl-2 proteins. This was the first report on the DARS-AS1/miR-188-5p/KLF12 axis and offered a novel strategy for early diagnosis, a new therapeutic method, and an improved prognosis for LUAD.

LncRNA LINC00662 Exerts an Oncogenic Effect on Osteosarcoma by the miR-16-5p/ITPR1 Axis

Background

Osteosarcoma (OS) is one of the most malignant bone tumors and has a high metastatic rate. Increasing research has demonstrated the vital roles of long noncoding RNAs (lncRNAs) in human cancers, including OS. LncRNA LINC00662 has been revealed to act as an oncogene involved in multiple tumor progression. This study aimed to investigate the expression pattern, function, and regulatory mechanism of LINC00662 in OS.

Methods

Patients who underwent OS surgery were involved in this study. Experiments including RT-qPCR, MTT, western blot, FISH, RNA pull-down, luciferase reporter, colony formation, transwell invasion and migration, and sphere formation assay were performed to investigate the regulatory role of LINC00662 in OS.

Results

In the present study, our findings demonstrated the upregulation of LINC00662 expression in OS tissues and cells, and high expression of LINC00662 predicted a poor clinical prognosis of patients' iNOS. Through a series of in vivo assays, LINC00662 knockdown suppressed OS cell proliferation, invasion, migration, and stemness property maintenance. Further mechanistical investigations indicated that LINC00662 functioned as a competing endogenous RNA (ceRNA) for sponging microRNA-16-5p (miR-16-5p) to upregulate the expression of IP receptor type 1 (ITPR1) in OS cells. Restoration assays validated the involvement of ITPR1 in LINC00662-mediated regulation of cell functions in OS.

Conclusion

LINC00662 exerts oncogenic functions in OS by targeting the miR-16-5p/ITPR1 axis.

LncRNA PTTG3P induced aberrant glycosylated IgA1 production and B cell growth in IgA nephropathy

Growing evidences suggested that lncRNAs played functional role in several cell functions such as cell growth, invasion, migration, metabolize, apoptosis, and differentiation. However, roles of lncRNA in the development and progression of IgAN remain unknown. In this reference, we indicated that PTTG3P level was overexpressed in IgAN samples compared to healthy subject. PTTG3P expression was also higher in urinary of IgAN cases than in urinary of healthy control. Furthermore, the urinary expression of PTTG3P was correlated with PTTG3P expression in intra-renal of IgAN cases. PTTG3P overexpression induced B cell growth and enhanced cyclin D1 and ki-67 expression. Overexpression of PTTG3P induced IL-1β and IL-8 production. miR-383 level was decreased in IgAN samples compared to healthy subject. In addition, miR-383 expression was also lower in urinary of IgAN cases than in urinary of healthy control. Elevated miR-383 expression decreased luciferase intensity regulated with PTTG3P, while overexpression of miR-383 had no effect on luciferase intensity of the mutant PTTG3P. PTTG3P overexpression suppressed miR-383 expression in B cells. Ectopic miR-383 expression suppressed B cell growth and IL-1β and IL-8 production. Finally, we showed that overexpression of PTTG3P promoted B cell growth and IL-1β and IL-8 production via regulating miR-383. There results proved that PTTG3P played crucial role in progression of IgAN.

LINC00987 knockdown inhibits the progression of acute myeloid leukemia by suppressing IGF2BP2-mediated PA2G4 expression

This study aimed to investigate the role and potential mechanisms of LINC00987 in acute myeloid leukemia (AML) progression. The expression of LINC00987 in bone marrow specimens of AML patients and cell lines was measured by quantitative reverse transcription PCR (RT-qPCR). Small interfering RNA targeting LINC00987 (si-LINC00987) was transfected into AML cell lines HL-60 and KG-1, and the proliferation, invasion and apoptosis were detected with Cell Counting Kit-8 (CCK-8), Transwell and flow cytometry, respectively. Moreover, the binding between LINC00987 and insulin like growth factor 2 mRNA binding protein 2 (IGF2BP2) was validated with an RNA pull-down assay. Co-immunoprecipitation assay was used to verify the binding between IGF2BP2 and proliferation-associated 2G4 (PA2G4). Then rescue experiments were performed to explore the effects of LINC00987/IGF2BP2/PA2G4 axis on HL-60 and KG-1 cell functions. Additionally, HL-60 cells transfected with si-LINC00987 were injected into mice, followed by the evaluation of xenograft tumor growth. LINC00987 was upregulated in AML patient specimens and cell lines. LINC00987 knockdown inhibited proliferation and invasion and promoted apoptosis in AML cells. LINC00987 could bind with IGF2BP2 and promote its expression, and IGF2BP2 overexpression reversed the effects of LINC00987 knockdown on the proliferation, invasion and apoptosis in AML cells. Besides, IGF2BP2 could bind with PA2G4. IGF2BP2 knockdown inhibited proliferation and invasion, and promoted apoptosis in AML cells, whereas PA2G4 overexpression reversed these effects. Additionally, the LINC00987 knockdown inhibited the xenograft tumor growth of AML in vivo. Knockdown of LINC00987 inhibits AML cell proliferation and invasion, and promotes apoptosis in vitro and reduces tumor growth in vivo by suppressing IGF2BP2-mediated PA2G4 expression.

Emerging roles of a pivotal lncRNA SBF2-AS1 in cancers

Long non-coding RNAs refer to transcripts over 200 nt in length that lack the ability to encode proteins, which occupy the majority of the genome and play a crucial role in the occurrence and development of human diseases, especially cancers. SBF2-AS1, a newly identified long non-coding RNA, has been verified to be highly expressed in diversiform cancers, and is involved in processes promoting tumorigenesis, tumor progression and tumor metastasis. Moreover, upregulation of SBF2-AS1 expression was significantly related to disadvantageous clinicopathologic characteristics and indicated poor prognosis. In this review, we comprehensively summarize the up-to-date knowledge of the detailed mechanisms and underlying functions of SBF2-AS1 in diverse cancer types, highlighting the potential of SBF2-AS1 as a diagnostic and prognostic biomarker and even a therapeutic target.

Downregulation of lncRNA SBF2-AS1 inhibits hepatocellular carcinoma proliferation and migration by regulating the miR-361-5p/TGF-β1 signaling pathway

SBF2-AS1 is an oncogenic long non-coding RNA (lncRNA). However, its role and mechanism in hepatocellular carcinoma (HCC) is still not completely clear. The HepG2, Hep3B, Bel-7402 and HL-7702 cell lines were used in our experiments. The CCK-8 kit and EdU staining were applied to detect cell viability and multiplication. The wound healing and Boyden chamber cell migration assays were employed to test the migration ability of cells. The levels of TGF-β1 mRNA, lncRNA SBF2-AS1, and miR-361-5p were assessed by real-time PCR. TGF-β1 protein levels were evaluated by western blotting. The direct interaction between miR-361-5p and TGF-β1 was determined by luciferase reporter assays. A xenograft mouse model (XMM) was established to comprehensively study the effect and mechanisms of lncRNA SBF2-AS1. lncRNA SBF2-AS1 concentration in HCC cells exceeded that in a normal hepatocyte cell line. The downregulation of lncRNA SBF2-AS1 upregulated miR-361-5p levels in HCC cells. And, miR-361-5p negatively regulate TGF-β1 expression in HCC cells. The suppression of miR-361-5p attenuated the influence of lncRNA SBF2-AS1 downregulation on the viability, proliferation, and migration capability of HCC cells. Further, the downregulation of lncRNA SBF2-AS1 inhibited neoplasm growth in an XMM of HCC. Simultaneously, miR-361-5p was upregulated and TGF-β1 was downregulated after lncRNA SBF2-AS1 knocked down. In conclusion, downregulation of lncRNA SBF2-AS1 inhibits HCC proliferation and migration through the regulation of the miR-361-5p/TGF-β1 signaling pathway.

Long noncoding RNA TMPO-AS1/miR-126-5p/BRCC3 axis accelerates gastric cancer progression and angiogenesis via activating PI3K/Akt/mTOR pathway

BACKGROUND AND AIM

Gastric cancer (GC) is an aggressive tumor featured by uncontrolled cell proliferation and metastasis. In recent years, long noncoding RNAs (lncRNAs) act as crucial regulators and biological markers in multiple cancers. LncRNA TMPO-AS1 has been revealed to be an oncogene in some cancers. Nevertheless, there is little known about the biological role of TMPO-AS1 in GC.

METHODS

Reverse transcription-quantitative polymerase chain reaction analysis was used to examine the expression level of TMPO-AS1 in GC tissues and cells. Cell Counting Kit-8, colony formation, wound healing assays, and western blot analysis were performed to determine the role of TMPO-AS1 in GC cells. RNA pull-down, luciferase reporter, and RNA immunoprecipitation assays were used to test the interaction among TMPO-AS1, miR-126-5p, and BRCC3.

RESULTS

TMPO-AS1 was highly expressed in GC tissues and cells. Upregulated TMPO-AS1 was closely associated with adverse prognosis of GC patients. Functional assays showed that TMPO-AS1 promoted GC cell proliferation, migration, and angiogenesis. Furthermore, it was found that TMPO-AS1 acted as a competing endogenous RNA for miR-126-5p to upregulate BRCC3 expression. Rescue assays revealed that TMPO-AS1 facilitated cellular progression of GC by sponging miR-126-5p and upregulating BRCC3. In addition, we found that the effects of the TMPO-AS1/miR-126-5p/BRCC3 axis on GC cell progression were related to the PI3K/Akt/mTOR pathway.

CONCLUSIONS

Our study demonstrated that the TMPO-AS1/miR-126-5p/BRCC3 axis was involved in GC progression via the regulation of PI3K/Akt/mTOR pathway, which might provide a potential therapeutic strategy for GC.

Prognostic Value of Immune-Related lncRNA SBF2-AS1 in Diffuse Lower-Grade Glioma

LncRNA SET-binding factor 2 (SBF2) antisense RNA1 (SBF2-AS1) has been proven to play an oncogenic role in various types of tumors, but the prognostic role of SBF2-AS1 in tumors, especially in diffuse lower-grade glioma (LGG), is still unclear. Here, we aimed to investigate the prognostic value of SBF2-AS1 in LGG. The LGG expression profiles from The Cancer Genome Atlas (TCGA, n = 524) and Chinese Glioma Genome Atlas (CGGA, n = 431) were mined by Kaplan-Meier analysis, Cox regression analysis, Chi-square test and GSEA analysis. Through Kaplan-Meier analysis, we found the prognosis of LGG patients with high expression of SBF2-AS1 were worse than that of patients with low expression (Log Rank P < 0.001). Cox analysis showed SBF2-AS1 was an independent prognostic factor for poorer overall survival in LGG (P < 0.05). SBF2-AS1 was found to be significantly related to IDH mutation status and SBF2-AS1 was highly expressed in IDH wildtype group. GSEA analysis obtained a total of 126 GO terms and 6 KEGG pathways that were significantly enriched in SBF2-AS1 high expression phenotype (NOM P value < 0.05). We found these 126 GO terms and KEGG pathways were mainly related to immunity. In conclusion, lncRNA SBF2-AS1 expression is an immune-related lncRNA associated with unfavorable overall survival in LGG. SBF2-AS1 could be a reliable prognostic biomarker for patients with LGG.

A novel lincRNA identified in buffalo oocytes with protein binding characteristics could hold the key for oocyte competence

Studying the maternal oocyte-specific genes, in farm animals is a significant step towards delineating the underlying mechanisms that regulate oocyte quality, early embryonic development and survival. With the creation of buffalo oocyte-specific subtracted cDNA library, it has raised new questions which need to be answered. The present study has characterized one of the ESTs selected from the library and highlighted its importance in the oocyte quality. The selected EST was made full length by RLM-RACE and four transcript variants were identified. Bioinformatics analysis indicated the novelty of full-length transcript along with conserved intergenic nature. The largest transcript was identified as long intergenic noncoding RNA based upon coding potential calculator output. The expression analysis at different hours of oocyte maturation showed a significant variation in developmentally competent oocytes to that of incompetent ones. Along with this, the transcript was also found to have protein binding ability which was confirmed by RNA electrophoretic mobility shift assay. The protein used in the experiment was isolated from oocyte and cumulus cells via sonication. A novel lincRNA has been reported here that might have an important role in maturation of oocytes, inferred from its relative gene expression study and protein binding characteristics.

Long noncoding RNA FTX ameliorates hydrogen peroxide-induced cardiomyocyte injury by regulating the miR-150/KLF13 axis

Background

Myocardial reperfusion is an effective therapy for acute myocardial infarction (AMI). However, ischemia/reperfusion (I/R) injury following myocardial reperfusion is a significant limitation for AMI treatment. Five prime to Xist (FTX) was recognized as a biomarker of multiple diseases, including heart disease. However, the molecular mechanism of FTX in I/R injury is unclear.

Methods

Cell viability was evaluated by using cell counting kit-8 (CCK-8) assay. Apoptosis was analyzed by using a caspase-3 activity detection kit and flow cytometry. The expression of FTX, microRNA (miR)-150, and Kruppel-like factor 13 (KLF13) was measured by quantitative reverse transcription-polymerase chain reaction (qRT-PCR). The interaction of miR-150 and FTX or KLF13 was confirmed by a dual-luciferase reporter and RNA immunoprecipitation (RIP) assays. Protein expression of KLF13 was examined by Western blot. The role of FTX was detected in I/R-injured heart tissues in vivo.

Results

Hydrogen peroxide (H₂O₂) induced cardiomyocyte injury by decreasing cell viability and expediting cell apoptosis. However, FTX alleviated cardiomyocyte injury by promoting cell proliferation and restricting cell apoptosis of H9C2 cells that were treated with H₂O₂. In addition, we discovered that FTX directly interacted with miR-150, while KLF13 was a target of miR-150. Rescue experiments showed that miR-150 neutralized the FTX-mediated promotion of cell progression and restriction of cell apoptosis in H9C2 cells treated with H₂O₂. KLF13 knockdown restored the effect of miR-150 on increased proliferation and decrease in apoptosis in H₂O₂-treated cardiomyocytes. Furthermore, FTX enhanced the expression of KLF13 protein through interaction with miR-150. Upregulation of FTX repressed apoptosis in I/R-injured heart tissues in vivo.

Conclusion

FTX relieves H₂O₂-induced cardiomyocyte injury by increasing KLF13 expression via depletion of miR-150, thus providing a novel therapeutic target for the alleviation of I/R injury.

Long non-coding RNA DSCAM-AS1 contributes to the tumorigenesis of cervical cancer by targeting miR-877-5p/ATXN7L3 axis

Cervical cancer (CC) is ranked as the fourth most common cancer that occurs in women universally, which normally causes pain in the lower belly. Plenty of studies have stated that the expression of long non-coding RNAs (lncRNAs) is linked to the cellular development of many kinds of cancers. DSCAM-AS1 has been reported to act as an oncogene in other cancer types and the aim of our study was to uncover the function and regulatory mechanism of DSCAM-AS1 in CC. In this research, our findings presented that DSCAM-AS1 expression was up-regulated in CC cells. DSCAM-AS1 led to the development of CC by enhancing cell proliferation, migration and invasion ability. DSCAM-AS1 was verified to combine with miR-877-5p and down-regulate the expression of miR-877-5p. Results also showed that ATXN7L3 was a downstream target gene of miR-877-5p and it was unfavorably modulated by miR-877-5p. Enhanced expression of ATXN7L3 counterbalanced the DSCAM-AS1 knockdown effect on the progression of CC. This was the first time to analyze the underlying regulatory mechanism of the oncogenic DSCAM-AS1. Our findings clarified that DSCAM-AS1 played as an oncogenic lncRNA by targeting miR-877-5p/ATXN7L3 axis to promote CC progression, which may provide insights into the prevention of CC.

LncRNA CASC2 Alleviates the Progression of Diabetic Nephropathy by Regulating the miR-144/SOCS2 Signalling Axis

BACKGROUND

Diabetic nephropathy constitutes a large proportion of end-stage kidney failure in diabetic patients. However, the underlying molecular mechanisms remain unclear.

METHODS

Db/db diabetic mouse models and high glucose (HG)-induced human renal mesangial cells (HRMCs) were used as research models in vivo and in vitro. The expression of cancer susceptibility candidate 2 (CASC2) was quantified by qRT-PCR. The regulatory role of CASC2 in cell apoptosis, inflammatory factor release, and fibrosis was verified by flow cytometry, qRT-PCR, and Western blot assay, respectively. The bioinformatics prediction software DIANA and starBase v2.0 were used to predict the putative binding sites. The interactions among CASC2, miR-144, and SOCS2 were explored by the luciferase assay and Western bolt assay.

RESULTS

The expression of CASC2 in diabetic mouse models and HG-induced HRMCs was lower than that in the control (p < 0.05). Overexpression of CASC2 resulted in a decrease in the apoptosis rate, inflammatory factor release (TNF-α, IL-6, and IL-1β), expression of cleaved caspase-3, and fibrotic proteins (fibronectin, Col-IV, and TGF-β1) and an increase in Bcl-2 expression. Inhibition of CASC2 caused increased expression of miR-144. Furthermore, mechanistic investigations confirmed that activation of the miR-144/SOCS2 regulatory loop by overexpression of miR-144 reversed the in vitro effects of CASC2 on inhibiting cell apoptosis, inflammatory factor release, and fibrosis. In addition, simultaneous overexpression of miR-144 and SOCS2 further increased the inhibition of cell apoptosis, inflammatory factor release, and fibrosis by CASC2.

CONCLUSION

CASC2 could alleviate the degree and process of apoptosis, inflammation, and fibrosis in diabetic nephropathic models by regulating the miR-144/SOCS2 axis.

Downregulation of long non-coding RNA MAFG-AS1 represses tumorigenesis of colorectal cancer cells through the microRNA-149-3p-dependent inhibition of HOXB8

Background

Colorectal cancer (CRC) is considered as the second common death-induced cancer. More recently, association of long non-coding RNAs (lncRNAs) with CRC has been extensively investigated. Therefore, the present study was performed to determine whether lncRNA MAF BZIP Transcription Factor G Antisense RNA 1 (MAFG-AS1) could regulate biological activities of CRC cells and unravel the underlying mechanisms.

Methods

CRC and corresponding adjacent tissues were collected to determine the expression of lncRNA MAFG-AS1, microRNA-149-3p (miR-149-3p) and homeobox B8 (HOXB8) by RT-qPCR. Dual luciferase reporter gene assay was used to explore the targeting relationship between miR-149-3p and lncRNA MAFG-AS1 and between miR-149-3p and HOXB8, followed by RNA immunoprecipitation for verification. Migration, proliferation, invasion, and apoptosis of HCT116 and LoVo cells were examined when lncRNA MAFG-AS1 was silenced or miR-149-3p was overexpressed. Furthermore, tumorigenicity of HCT116 and LoVo cells was measured in vivo by tumor xenograft in nude mice.

Results

LncRNA MAFG-AS1 and HOXB8 were found to be highly expressed in CRC tissues and cells, while miR-149-3p was under-expressed. LncRNA MAFG-AS1 negatively regulated miR-149-3p while miR-149-3p downregulated HOXB8. In addition, lncRNA MAFG-AS1 silencing by shRNA or miR-149-3p upregulation by mimic suppressed the migration, proliferation, invasion and tumorigenesis but promoted the apoptosis of HCT116 and LoVo cells.

Conclusion

Taken together, lncRNA MAFG-AS1 downregulation inhibits the malignant behaviors of CRC cells by upregulating miR-149-3p and downregulating HOXB8, providing a potential therapeutic target for CRC treatment.

LINC00963 facilitates acute myeloid leukemia development by modulating miR-608/MMP-15

Despite continuous improvements of AML therapy, the prognosis of AML patients remains unsatisfactory. Recently, lncRNAs have been reported to participate in the development of AML. Our data demonstrated that MMP15 and LINC00963 were upregulated and miR-608 was decreased in AML cells (THP-1, HL-60, HEL and MOLM-13) compared to HS-5 cells. RT-qPCR results showed that LINC00963 levels were higher in the serum and bone marrow of AML cases than in controls. Moreover, overexpression of LINC00963 promoted AML cell growth and EMT progression in both THP-1 and HL-60 cells. Furthermore, miR-608 levels were downregulated in the serum and bone marrow of AML cases compared with controls, and Pearson's correlation analysis indicated that LINC00963 was negatively correlated with miR-608 in the serum and bone marrow of AML samples. In addition, we demonstrated that LINC00963 sponged miR-608 expression and that MMP-15 was a target of miR-608 in AML cells. Finally, rescue experiments indicated that ectopic expression of LINC00963 accelerated cell growth and EMT development by modulating MMP-15. These data demonstrated that LINC00963 acted as an oncogene and may be a potential target for AML treatment.

Long noncoding RNA SBF2-AS1 contributes to the growth and metastatic phenotypes of NSCLC via regulating miR-338-3p/ADAM17 axis

Non-small cell lung cancer (NSCLC) is a type of refractory malignant lung cancer with a high rate of metastasis and mortality. Currently, long non-coding RNA (lncRNA) SBF2 Antisense RNA 1 (SBF2-AS1) is considered as a biomarker for a variety of tumors. However, the function of SBF2-AS1 in the growth and metastasis of NSCLC needs to be further studied. In this study, we revealed that SBF2-AS1 was overexpressed in NSCLC tissues compared with that in normal tissues. SBF2-AS1 silencing restrained the growth and aggressive phenotypes of NSCLC cell in vitro. Consistently, SBF2-AS1 knockdown hindered the growth of NSCLC cell in nude mice. The following luciferase reporter gene assay and RNA immunoprecipitation (RIP) assay suggested the relationship between miR-338-3p and SBF2-AS1. The rescue experiments showed that miR-338-3p inhibitor abolished SBF2-AS1 silencing caused inhibition on the growth, migration and invasiveness of NSCLC cell. The luciferase reporter assay and immunoblotting assay validated that A Disintegrin and Metalloprotease 17 (ADAM17) was a target of miR-338-3p. In addition, SBF2-AS1 positively regulated the level of ADAM17 through sponging for miR-338-3p. Finally, we revealed that SBF2-AS1 contributed to the proliferation and metastatic phenotypes of NSCLC cell via regulating miR-338-3p/ADAM17 axis.

Overexpression of Nuclear Enriched Autosomal Transcript 1 Facilitates Cell Proliferation, Migration Invasion, and Suppresses Apoptosis in Endometrial Cancer by Targeting MicroRNA-202-3p/T Cell Immunoglobulin and Mucin Domain 4 Axis

Background: Endometrial cancer (EC) is an intractable gynecological cancer with increasing incidence and mortality worldwide. Accumulating studies indicated that long noncoding RNA nuclear enriched autosomal transcript 1 (NEAT1) was a novel oncogene implicated in a variety of cancers. However, whether NEAT1 could accelerate cell growth in EC is unclear. Methods: NEAT1, microRNA (miR)-202-3p, and T cell immunoglobulin and mucin domain 4 (TIMD4) levels were detected by quantitative real-time polymerase chain reaction. Cell proliferation and apoptosis were examined by cell counting kit-8 and flow cytometry. Transwell assay was employed for the evaluation of cell migration and invasion. The relationship between miR-202-3p and NEAT1 or TIMD4 was determined by luciferase reporter system. TIMD4 protein expression was assessed by Western blot assay. Results: NEAT1 was upregulated, whereas miR-202-3p was downregulated in EC tumors and cells. Depletion of NEAT1 restrained EC cell proliferation, migration, invasion, and improved apoptosis. MiR-202-3p was targeted by NEAT1 and could bind to TIMD4. Subsequently, it is observed that miR-202-3p inhibitor neutralized NEAT1 silencing mediated suppression on EC cell progression. Meanwhile, TIMD4 rescued miR-202-3p induced inhibition on cell progression in EC. Furthermore, it was obvious that NEAT1 facilitated TIMD4 expression by absorbing miR-202-3p in EC. Conclusions: Upregulation of NEAT1 accelerated EC cell progression through sponging miR-202-3p to facilitate TIMD4 expression, providing potential novel treatment method for EC.

miR-188-5p Promotes Tumor Growth by Targeting CD2AP Through PI3K/AKT/mTOR Signaling in Children with Acute Promyelocytic Leukemia

PURPOSE

Pediatric acute promyelocytic leukemia (APL) accounts for 10% of pediatric acute myelogenous leukemia (AML) case and is accompanied by a tendency to hemorrhage. miR-188-5p plays an important role in adult AML. Therefore, the purpose of this study was to explore the effects of miR-188-5p on cell proliferation and apoptosis and tumor growth, and its mechanism in pediatric APL patients.

MATERIALS AND METHODS

Survival-associated miRNAs or mRNAs from TCGA database associated with AML were identified via using the "survival R" package in R language. CCK8, clone formation, flow cytometry, RT-PCR, immunohistochemistry and Western blot assays were used to detect the viability, proliferation, apoptosis, cell cycle, and related gene expression in APL cell lines. The prognostic value of miR-188-5p was evaluated using a ROC curve. The tumorigenic ability of APL cell lines was determined using a nude mouse transplantation tumor experiment. Tumor cell apoptosis was determined by TUNEL assay in vivo. The target genes of miR-188-5p were predicted using the miRDB, miRTarBase, and TargetScan databases. A PPI network was constructed using STRING database and the hub gene was identified using the MCODE plug-in of the Cytoscape software. The DAVID database was used to perform GO and KEGG pathway enrichment analyses. A luciferase reporter assay was used to demonstrate the binding of miR-188-5p to CD2AP.

RESULTS

miR-188-5p overexpression or CD2 associated protein (CD2AP) inhibition was significantly associated with poor survival in pediatric APL patients. Upregulation of miR-188-5p was identified in the blood of pediatric APL patients and cell lines. Increased expression of miR-188-5p also promoted the viability, proliferation, and cell cycle progression, and reduced the apoptosis of APL cells. Additionally, upregulation of miR-188-5p regulated the expressions of cyclinD1, p53, Bax, Bcl-2 and cleaved caspase-3. The area under the ROC curve (AUC) of miR-188-5p was 0.661. miR-188-5p overexpression increased the tumorigenic ability of APL and Ki67 expression, and reduced cell apoptosis in vivo. CD2AP was identified as the only overlapping gene from the list of miR-188-5p target genes and survival-related mRNAs of the TCGA database. It was mainly enriched in the "biological process (BP)" and "cellular component (CC)" terms, and was downregulated in the blood of pediatric APL patients and cell lines. The luciferase reporter, RT-PCR, and Western blot assays demonstrated that the binding of miR-188-5p to CD2AP. CD2AP inhibition promoted the proliferation and inhibited the apoptosis of APL cells. Rescue experiments showed that inhibition of miR-188-5p inhibited cell proliferation, activated the PI3K/AKT/mTOR signaling pathway, induced G0/G1 phase arrest, regulated gene expression, and promoted cell apoptosis, which were reversed by CD2AP inhibition.

CONCLUSION

miR-188-5p, an oncogene, promoted tumor growth and progression of pediatric APL in vitro and in vivo via targeting CD2AP and activating the PI3K/AKT/mTOR signaling pathway.

Long Noncoding RNASBF2-AS1 Promotes Gastric Cancer Progression via Regulating miR-545/EMS1 Axis

Objective

Long noncoding RNA (LncRNA) SBF2-AS1 was reportedly to function as an oncogene in several types of cancers, such as hepatocellular carcinoma, nonsmall cell lung cancer, glioma, and colorectal cancer. However, the biological roles and regulatory mechanisms of SBF2-AS1 in gastric cancer (GC) are unknown.

Methods

The expression of SBF2-AS1 and miR-545 were examined in GC tissues and cell lines via real-time quantitative PCR. The relationship of SBF2-AS1 with miR-545 was verified via dual-luciferase reporter gene assay and RNA immunoprecipitation. The influences of SBF2-AS1 on cell proliferation, migration, and invasion were determined using cell counting Kit-8 (CCK-8), wound healing, and transwell invasion assays, respectively.

Results

LncRNA SBF2-AS1 expression was upregulated in GC tissues, especially in advanced clinical stage cases. Moreover, increased SBF2-AS1 indicated a poor survival rate. Functionally, the downregulation of SBF2-AS1 by siRNA in GC cells suppressed the proliferation, migration, and invasion. In terms of mechanism, SBF2-AS1 can directly bind to miR-545 and regulate its expression. Moreover, SBF2-AS1 knockdown significantly decreased the expression of EMS1, which was the direct target of miR-545. Importantly, inhibition of miR-545 or overexpression of EMS1 partially reversed SBF2-AS1-depletion-caused suppression on proliferation, migration, and invasion.

Conclusion

These findings elucidated a crucial role of SBF2-AS1 as a miR-545 sponge in GC cells, suggesting that SBF2-AS1 might be a potential target for GC.

Competing endogenous RNA regulation in hematologic malignancies

The clinical application of cytogenetic analysis and molecular-targeted drugs has dramatically improved the prognosis for many patients with hematologic malignancy, especially for those with chronic myeloid leukemia (CML) and acute promyelocytic leukemia (APL). Nevertheless, the treatment of hematologic malignancies is still faced with problems, such as disease recurrence and drug resistance, so further exploring the underlying molecular mechanism is urgent. With the discovery of different RNA species, the mechanism of RNA-RNA interaction has caught more and more attention. "Competing endogenous RNA (ceRNA) hypothesis" is one of the fascinating products of recent researches. CeRNAs are endogenous RNA transcripts that share mutual microRNA response elements (MREs) and regulate expression of each other by competing for the same microRNAs pools. The hypothesis links different RNA species together and enriches our understanding of the human genome. Here, we introduce the hypothesis critically, summary the research progress in the field of hematologic malignancies and the current investigation methods, and address its promising clinical value in offering new predictive, prognostic biomarkers and therapeutic targets.

Three-dimensional DNA tweezers serve as modular DNA intelligent machines for detection and regulation of intracellular microRNA

MicroRNAs (miRNAs) as novel biological targets are hardly applied in diagnostic and treatment of diseases, as they are difficult to be accurately detected and regulated. Here, we demonstrated a modular DNA intelligent machine named three-dimensional tweezers (TD-tweezers) to image and regulate miRNAs in living cells simultaneously. Fluorophore or miRNA inhibitors are introduced as detecting or regulating parts to construct different types of TD-tweezers, and the conformational state of TD-tweezers is controlled by the target miRNAs. The TD-tweezers exhibit excellent sensitivity, specificity, stability, and biocompatibility in vitro and in vivo, and their function of regulating miRNAs was confirmed by the up-regulated expression of downstream genes and proteins. Moreover, the TD-tweezers have been tested in whole blood, preliminarily verifying their clinical application potential. This design provides a multifunctional platform that can achieve efficient detection and regulation of targets within living cells and promote the development of DNA intelligent machines.

Long non-coding RNA UCA1 modulates cell proliferation and apoptosis by regulating miR-296-3p/Myc axis in acute myeloid leukemia

Acute myeloid leukemia (AML) is a common hematopoietic malignancy with a generally poor prognosis. Long non-coding RNA (lncRNA) urothelial carcinoma-associated 1 (UCA1) has been identified as an oncogene in various malignancies including AML. However, the role and mechanisms of UCA1 in AML tumorigenesis were incompletely understood. Hence, this study aims to investigate whether UCA1 regulates AML progression by miR-296-3p/Myc axis. Cell proliferation and apoptosis were evaluated by MTT assay and flow cytometry, respectively. Luciferase reporter assay was performed to analyze the interaction between miR-296-3p and UCA1 or Myc. The results showed that UCA1 knockdown inhibited proliferation and induced apoptosis in AML cells (U937 and HL60). Mechanistically, UCA1 acted as a sponge of miR-296-3p by binding to miR-296-3p. Myc, a target of miR-296-3p, was positively regulated by UCA1. Functional assay showed that the anti-AML effect of UCA1 knockdown could be abrogated by miR-296-3p inhibition and Myc overexpression. Moreover, UCA1 knockdown inhibited AML cell tumorigenesis in vivo, which was associated with regulation of miR-296-3p and Myc expression. In conclusion, UCA1 modulates AML progression by regulating miR-296-3p/Myc axis.

LncRNA TUG1 Regulates Cell Viability and Death by Regulating miR-193a-5p/Rab10 Axis in Acute Myeloid Leukemia

Background

Acute myeloid leukemia (AML) is a serious threat to human health. Long non-coding RNA (lncRNA) Taurine-Upregulated Gene1 (TUG1) has been reported to participate in the development and progression of several cancers, including AML. Herein, we aimed to investigate the pathognomonic role of TUG1 in AML cells and its potential mechanistic pathway.

Methods

Quantitative real-time PCR (qRT-PCR) assay was applied to detect the expression levels of lncRNA TUG1, miR-193a-5p and Rab10 in AML bone marrow and cell lines. The CCK-8 assay was conducted to assess the cell viability of AML HL-60 and NB4 cells and cell apoptotic assay was performed to assess the cell death. Dual-luciferase reporter assay was carried out to clarify the relationships among TUG1, miR-193a-5p and Rab10. Also, the protein level of Rab10 was examined by Western blot assay.

Results

LncRNA TUG1 was up-regulated in AML bone marrow and cells. Functional analysis showed that the silencing of TUG1 suppressed cell viability, while promoted cell death in AML HL-60 and NB4 cells. TUG1 targeted miR-193a-5p and negatively regulated miR-193a-5p expression. Overexpressed miR-193a-5p resulted in the decrease of cell viability and the increase in the cell death in AML cells. Restoration experiments proved that TUG1 regulated the cell viability and death of AML cells through regulating the miR-193a-5p/Rab10 axis. Rab10 was a direct target of miR-193a-5p and was inversely regulated by miR-193a-5p. TUG1 regulated the cell viability and death of AML cells through upregulating Rab10.

Conclusion

Silencing of lncRNA TUG1 induces a cytotoxic effect on AML cell lines through sponging miR-193a-5p and the suppression of Rab10.

Down-regulated lncRNA SBF2-AS1 inhibits tumorigenesis and progression of breast cancer by sponging microRNA-143 and repressing RRS1

Background

Recently, the roles of long non-coding RNAs (lncRNAs) and microRNAs (miRNAs) in human diseases have been unveiled, this research was conducted to explore the impacts of lncRNA SET-binding factor 2-antisense RNA1 (SBF2-AS1), miR-143 and resistance to ralstonia solanacearum 1 (RRS1) on breast cancer (BC) development.

Methods

The expression of SBF2-AS1, miR-143 and RRS1 in BC tissues, as well as in MDA-MB-231 and MCF-7 cell lines were assessed. Subsequently, the cells were transfected with miR-143 mimics or/and silenced or overexpressed SBF2-AS1 plasmids, and their negative controls. Then the proliferation, colony formation ability, cell cycle arrest, apoptosis, invasion and migration of the cells were assessed through gain- and loss-of-function experiments. Furthermore, the tumor growth, ki-67 expression and apoptosis in vivo were observed by subcutaneous tumorigenesis in nude mice. Binding relation between SBF2-AS1 and miR-143, and that between miR-143 and RRS1 were confirmed.

Results

SBF2-AS1 and RRS1 were amplified, while miR-143 was reduced in BC tissues and cells. Reduced SBF2-AS1 and elevated miR-143 could repress the proliferation, invasion and migration via restraining RRS1 expression. Moreover, knockdown of SBF2-AS1 up-regulated miR-143 to promote the apoptosis of BC cells by downregulating RRS1, resulting in a prohibitive effect on the tumorigenesis and progression of BC. Results of in vivo experiments indicated that the inhibited SBF2-AS1 and overexpressed miR-143 could restrict BC cell proliferation and promote apoptosis, and decelerate tumor growth in xenografts.

Conclusion

We have discovered in this study that down-regulated SBF2-AS1 could inhibit tumorigenesis and progression of BC by up-regulation miR-143 and repressing RRS1, which provides basic therapeutic considerations for a novel target against BC.

MicroRNAs: pivotal regulators in acute myeloid leukemia

MicroRNAs are a class of small non-coding RNAs that are 19-22 nucleotides in length and regulate a variety of biological processes at the post-transcriptional level. MicroRNA dysregulation disrupts normal biological processes, resulting in tumorigenesis. Acute myeloid leukemia is an invasive hematological malignancy characterized by the abnormal proliferation and differentiation of immature myeloid cells. Due to the low 5-year survival rate, there is an urgent need to discover novel diagnostic markers and therapeutic targets. In recent years, microRNAs have been shown to play important roles in hematological malignancies by acting as tumor suppressors and oncogenes. MicroRNAs have the potential to be a breakthrough in the diagnosis and treatment of acute myeloid leukemia. In this review, we summarize the biology of microRNAs and discuss the relationships between microRNA dysregulation and acute myeloid leukemia in the following aspects: signaling pathways, the abnormal biological behavior of acute myeloid leukemia cells, the clinical application of microRNAs and competing endogenous RNA regulatory networks.

LncRNA SBF2-AS1 affects the radiosensitivity of non-small cell lung cancer via modulating microRNA-302a/MBNL3 axis

Background: Long non-coding RNAs (lncRNAs) have been reported to participate in many diseases including non-small cell lung cancer (NSCLC), thus our objective was to investigate the impact of lncRNA SBF2-AS1 modulating microRNA-302a (miR-302a) expression on radiosensitivity of NSCLC.Methods: The expression of SBF2-AS1, miR-302a and muscleblind-like 3 (MBNL3) in NSCLC tissues of the radiotherapy-sensitive and radiotherapy-resistant groups was tested. The radiosensitivity of parent and resistant strains (NCI-H1299 and NCI-H1299_R cells) was detected. Further, cells were treated with si-SBF2-AS1 and miR-302a mimics to determine their roles in proliferation and apoptosis of parent strain and resistant strain cells as well as transfected cells. The in-vivo growth capacity of the cells and the effect of radiotherapy on tumor size of NSCLC were detected.Results: Up-regulated SBF2-AS1 and MBNL3 and down-regulated miR-302a in NSCLC tissues of the radiotherapy resistant group. Overexpression of SBF2-AS1 and MBNL3 and low expression of miR-302a were witnessed in NCI-H1299_R cells. Down-regulated SBF2-AS1 or up-regulated miR-302a suppressed the proliferation while boosted the apoptosis of NCI-H1299 cells and decreased the radioresistance of the NCI-H1299_R cells. Silencing SBF2-AS1 or up-regulating miR-302a restrained tumor growth in vivo.Conclusion: Our study presents that high expression of miR-302a or inhibition of SBF2-AS1 can enhance the radiosensitivity and apoptosis of NSCLC cells through downregulation of MBNL3, which is a therapeutic target for NSCLC.

Long noncoding RNA NNT-AS1 enhances the malignant phenotype of bladder cancer by acting as a competing endogenous RNA on microRNA-496 thereby increasing HMGB1 expression

The long noncoding RNA nicotinamide nucleotide transhydrogenase antisense RNA 1 (NNT-AS1) is a key malignancy regulator in a variety of human cancers. In this study, we first measured the expression of NNT-AS1 in bladder cancer and examined its role in cancer progression. The mechanisms behind the oncogenic functions of NNT-AS1 in bladder cancer were explored. We found that NNT-AS1 was upregulated in bladder cancer tissues and cell lines. This increased expression demonstrated a significant correlation with advanced clinical stage, lymph node metastasis, and shorter overall survival. NNT-AS1 knockdown suppressed bladder cancer cell proliferation, migration, and invasion and facilitated apoptosis in vitro and hindered tumor growth in vivo. NNT-AS1 functioned as a competing endogenous RNA for microRNA-496 (miR-496), and the suppressive effects of NNT-AS1 knockdown on malignant characteristics were abrogated by miR-496 silencing. HMGB1 was identified as a direct target gene of miR-496 in bladder cancer, and HMGB1 expression was enhanced by NNT-AS1 via sponging of miR-496. In conclusion, the NNT-AS1–miR-496–HMGB1 pathway plays a significant role in the aggressive behavior of bladder cancer and may lead to new NNT-AS1–based diagnostics and therapeutics.

Identification and analysis of long non-coding RNAs that are involved in inflammatory process in response to transmissible gastroenteritis virus infection

Background

Transmissible gastroenteritis virus (TGEV) infection can cause acute inflammation. Long noncoding RNAs (lncRNAs) play important roles in a number of biological process including inflammation response. However, whether lncRNAs participate in TGEV-induced inflammation in porcine intestinal epithelial cells (IPECs) is largely unknown.

Results

In this study, the next-generation sequencing (NGS) technology was used to analyze the profiles of lncRNAs in Mock and TGEV-infected porcine intestinal epithelial cell-jejunum 2 (IPEC-J2) cell line. A total of 106 lncRNAs were differentially expressed. Many differentially expressed lncRNAs act as elements to competitively attach microRNAs (miRNAs) which target to messenger RNA (mRNAs) to mediate expression of genes that related to toll-like receptors (TLRs), NOD-like receptors (NLRs), tumor necrosis factor (TNF), and RIG-I-like receptors (RLRs) pathways. Functional analysis of the binding proteins and the up/down-stream genes of the differentially expressed lncRNAs revealed that lncRNAs were principally related to inflammatory response. Meanwhile, we found that the differentially expressed lncRNA TCONS_00058367 might lead to a reduction of phosphorylation of transcription factor p65 (p-p65) in TGEV-infected IPEC-J2 cells by negatively regulating its antisense gene promyelocytic leukemia (PML).

Conclusions

The data showed that differentially expressed lncRNAs might be involved in inflammatory response induced by TGEV through acting as miRNA sponges, regulating their up/down-stream genes, or directly binding proteins.

Long Noncoding RNAs in Acute Myeloid Leukemia: Functional Characterization and Clinical Relevance

Acute Myeloid Leukemia (AML) is the most common form of leukemia in adults with an incidence of 4.3 per 100,000 cases per year. Historically, the identification of genetic alterations in AML focused on protein-coding genes to provide biomarkers and to understand the molecular complexity of AML. Despite these findings and because of the heterogeneity of this disease, questions as to the molecular mechanisms underlying AML development and progression remained unsolved. Recently, transcriptome-wide profiling approaches have uncovered a large family of long noncoding RNAs (lncRNAs). Larger than 200 nucleotides and with no apparent protein coding potential, lncRNAs could unveil a new set of players in AML development. Originally considered as dark matter, lncRNAs have critical roles to play in the different steps of gene expression and thus affect cellular homeostasis including proliferation, survival, differentiation, migration or genomic stability. Consequently, lncRNAs are found to be differentially expressed in tumors, notably in AML, and linked to the transformation of healthy cells into leukemic cells. In this review, we aim to summarize the knowledge concerning lncRNAs functions and implications in AML, with a particular emphasis on their prognostic and therapeutic potential.

Long Non-coding RNAs in Myeloid Malignancies

Acute myeloid leukemia (AML) represents 80% of adult leukemias and 15-20% of childhood leukemias. AML are characterized by the presence of 20% blasts or more in the bone marrow, or defining cytogenetic abnormalities. Laboratory diagnoses of myelodysplastic syndromes (MDS) depend on morphological changes based on dysplasia in peripheral blood and bone marrow, including peripheral blood smears, bone marrow aspirate smears, and bone marrow biopsies. As leukemic cells are not functional, the patient develops anemia, neutropenia, and thrombocytopenia, leading to fatigue, recurrent infections, and hemorrhage. The genetic background and associated mutations in AML blasts determine the clinical course of the disease. Over the last decade, non-coding RNAs transcripts that do not codify for proteins but play a role in regulation of functions have been shown to have multiple applications in the diagnosis, prognosis and therapeutic approach of various types of cancers, including myeloid malignancies. After a comprehensive review of current literature, we found reports of multiple long non-coding RNAs (lncRNAs) that can differentiate between AML types and how their exogenous modulation can dramatically change the behavior of AML cells. These lncRNAs include: H19, LINC00877, RP11-84C10, CRINDE, RP11848P1.3, ZNF667-AS1, AC111000.4-202, SFMBT2, LINC02082-201, MEG3, AC009495.2, PVT1, HOTTIP, SNHG5, and CCAT1. In addition, by performing an analysis on available AML data in The Cancer Genome Atlas (TCGA), we found 10 lncRNAs with significantly differential expression between patients in favorable, intermediate/normal, or poor cytogenetic risk categories. These are: DANCR, PRDM16-DT, SNHG6, OIP5-AS1, SNHG16, JPX, FTX, KCNQ1OT1, TP73-AS1, and GAS5. The identification of a molecular signature based on lncRNAs has the potential for have deep clinical significance, as it could potentially help better define the evolution from low-grade MDS to high-grade MDS to AML, changing the course of therapy. This would allow clinicians to provide a more personalized, patient-tailored therapeutic approach, moving from transfusion-based therapy, as is the case for low-grade MDS, to the introduction of azacytidine-based chemotherapy or allogeneic stem cell transplantation, which is the current treatment for high-grade MDS.

Long non-coding RNA RPPH1 promotes the proliferation, invasion and migration of human acute myeloid leukemia cells through down-regulating miR-330-5p expression

Multiple studies have revealed that the long non-coding RNA RPPH1 (Ribonuclease P RNA Component H1) is involved in disease progression of solid tumors and neurodegenerative diseases. We aimed to explore the functions of RPPH1 in the pathogenesis of acute myeloid leukemia (AML) and the underlying molecular mechanisms. The expression of RPPH1 was examined in blood samples of AML patients and human AML cell lines including THP-1 and HL-60. The microRNAs (miRNAs) targets of RPPH1 were predicted with online tools and validated with the dual luciferase reporter assay. The malignant behaviors of AML cells with lentivirus medicated knockdown of RPPH1 and/or administration of miR-330-5p inhibitor were assessed. Cell proliferation was determined by the CCK-8 and EdU incorporation methods, and cell invasion and migration were assayed with transwell experiments. The effects of RPPH1 knockdown on in vivo tumor growth were evaluated in nude mice with xenografted THP-1 cells. RPPH1 was expressed in the AML tissues and cell lines and its high expression predicted worse overall survival in AML patients. miR-330-5p was validated to be a direct target of RPPH1. Knockdown of RPPH1 suppressed the proliferation, invasion and migration ability of human AML cells, which was partially reversed by additional administration with miR-330-5p inhibitor. RPPH1 knockdown significantly inhibited the growth of xenografted THP-1 tumor in nude mice. Our work highlights the contributions of RPPH1 in promoting AML progression through targeting miR-330-5p, and suggests that the RPPH1/miR-330-5p axis is a potential target for AML treatments.

Comprehensive analysis the potential biomarkers for the high-risk of childhood acute myeloid leukemia based on a competing endogenous RNA network

Acute myeloid leukemia (AML) is a common form of hematological malignancies, the discovery of non-coding RNA (ncRNA) plays an important role in diverse biological processes including hematopoietic differentiation and proliferation. However, the interaction mechanism of key RNAs and their regulatory network in childhood AML are still to be elucidated. RNA profiles were downloaded from the Therapeutically Applicable Research to Generate Effective Treatment (TARGET) database and identified specific lncRNAs, miRNAs, and mRNAs in high-risk group of childhood AML. A lncRNA-mRNA-miRNA ceRNA network in childhood AML was constructed. A total of 2064 mRNAs, 615 lncRNAs, and 60 miRNAs were identified as significantly differentially expressed, and 13 lncRNAs, 7 miRNAs, and 67 mRNAs were incorporated in the ceRNA network. Functional analysis showed that these DEmRNAs were significantly enriched in Ras signaling pathway, TGF-beta signaling pathway, and other tumor-related pathways. Among the network, 10 RNAs (LINC00471, hsa-mir-100, hsa-mir-150, ANP32E, ERMP1, MYO1B, PAPD7, PTGIS, TERF1, and VEGFA) was associated with high-risk group of childhood AML and functions were significant for prognosis. Then, these findings together provide a new insight into the pathogenesis of high-risk group of childhood AML that can assist clinicians clarify the function of lncRNA to guide the treatment and in-depth study.

High expression of long intergenic non-coding RNA LINC00662 contributes to malignant growth of acute myeloid leukemia cells by upregulating ROCK1 via sponging microRNA-340-5p

Long non-coding RNAs (lncRNAs) have emerged as crucial regulatory factors in diverse pathological processes, especially in tumorigenesis. Accumulating evidence has demonstrated that long intergenic non-coding RNA 00662 (LINC00662) is overexpressed in multiple cancers and facilitates cancer development and progression. However, whether LINC00662 is involved in acute myeloid leukemia (AML) remains unknown. This study was aimed to explore the expression, biological function and regulatory mechanism of LINC00662 in AML. Here, we found that LINC00662 was significantly increased in AML tissues and cell lines. Knockdown of LINC00662 significantly reduced the growth of AML cells and upregulated AML cell apoptosis. In contrast, overexpression of LINC00662 promoted AML cell growth. MicroRNA-340-5p (miR-340-5p) was predicted as a target of LINC00662. Luciferase reporter assays and RNA pull-down assays confirmed that LINC00662 directly interacted with miR-340-5p. Expression of miR-340-5p was downregulated in AML and silencing of LINC00662 upregulated miR-340-5p expression in AML cells. Moreover, overexpression of miR-340-5p inhibited cell growth and increased apoptosis in AML cells. Inhibition of miR-340-5p significantly reversed the inhibitory effect of LINC00662 silencing on AML cell growth. In addition, Rho-associated protein kinase 1 (ROCK1) was verified as a target gene of miR-340-5p in AML cells. Restoration of ROCK1 expression partially reversed LINC00662 silencing or miR-340-5p overexpression-mediated inhibitory effect on AML cell growth. Overall, our results demonstrate that LINC00662 contributes to the malignant growth of AML cells by upregulating ROCK1 via sponging miR-340-5p, highlighting the important role of the LINC00662/miR-340-5p/ROCK1 axis in regulating the malignant behavior of AML cells.