STAT1-mediated upregulation of lncRNA LINC00174 functions a ceRNA for miR-1910-3p to facilitate colorectal carcinoma progression through regulation of TAZ

A novel prognostic signature based on m5C‑related LncRNAs and its immunological characteristics in colon adenocarcinoma

BACKGROUND

Colon adenocarcinoma (COAD) has high mortality rates due to frequent resistance to treatment. 5-methylcytosine (m5C) is a crucial epigenetic modification of RNA, closely associated with tumorigenesis in various cancers. This study focuses on developing an m5C-related long non-coding RNA (lncRNA) signature to predict prognosis and explore potential therapeutic targets.

METHODS

Using data from The Cancer Genome Atlas (TCGA) and the Gene Expression Omnibus (GEO), we analyzed 18 m5C regulatory genes and their associated lncRNAs in COAD samples. Prognostic lncRNAs were identified through univariate Cox regression, and a risk model was constructed through LASSO regression analyses. Kaplan-Meier survival and receiver operating characteristic analyses were employed to validate the prognostic ability of the signature. Additionally, functional enrichment and immune infiltration analyses were conducted to investigate underlying biological pathways and immune characteristics of the risk groups. Tumor mutation burden and drug sensitivity analyses were also performed. Functional validation of NR2F2-AS1 was conducted through in vitro experiments.

RESULTS

We established a risk score signature comprising six lncRNAs associated with m5C regulators. Patients were classified into high- and low-risk groups based on the median risk score. This prognostic signature demonstrated significant accuracy and was independent of other clinical features. Immune cell infiltration analysis revealed correlations between the risk signature and various immune cell subtypes. Drug sensitivity analysis indicated the potential therapeutic value of our prognostic signature. Functional experiments confirmed that NR2F2-AS1 acts as a risk factor in the proliferation of colon cancer cells.

CONCLUSIONS

The m5C-related lncRNA signature serves as a reliable prognostic indicator for colon adenocarcinoma and provides new insights into the tumor immune microenvironment.

Transcriptional stress induces the overexpression of novel lncRNAs that regulate the BRCA1 locus

Long non-coding RNAs (lncRNAs) have been shown to play a role during transcriptional regulation in response to stress. However, their function under stress caused by transcriptional inhibition has not yet been addressed. Using genome-wide assays to elucidate the transcriptional response in human cells caused by RNA polymerase II transcription inhibition, we found three novel regulatory lncRNAs, TILR-1 , TILR-2 , and LINC00910 , that are upregulated as a response to this transcriptional stress. Knockdown experiments showed that the expression of these RNAs is interdependent, and together, they regulate transcription of the nearby BRCA1 locus. The lack of these novel regulatory transcripts also resulted in an increase in cellular proliferation and survival. Public transcriptomic data from different cell lines treated with a variety of transcriptional inhibitors or with heat shock and arsenic stress showed that TILR-1 , TILR-2 , and LINC00910 are commonly upregulated in a broad array of stress conditions. Evolutionary analysis showed that TILR-1 , TILR-2 , and LINC00910 are highly conserved among primates, and their emergence correlates with the duplication of the bidirectional promoter of BRCA1 and NBR1 . We conclude that that coordinate transcription of TILR-1 , TILR-2 , and LINC00910 is stimulated generally by stress and the resulting lncRNAs are novel, functionally-conserved regulators of the BRCA1 locus.

Hippo Signaling Pathway in Colorectal Cancer: Modulation by Various Signals and Therapeutic Potential

Colorectal cancer (CRC) stands as a significant global health issue, marked by elevated occurrence and mortality statistics. Despite the availability of various treatments, including chemotherapy, radiotherapy, and targeted therapy, CRC cells often exhibit resistance to these interventions. As a result, it is imperative to identify the disease at an earlier stage and enhance the response to treatment by acquiring a deeper comprehension of the processes driving tumor formation, aggressiveness, metastasis, and resistance to therapy. The Hippo pathway plays a critical role in facilitating the initiation of tumorigenesis and frequently experiences disruption within CRC because of genetic mutations and modified expression in its fundamental constituents. Targeting upstream regulators or core Hippo pathway components may provide innovative therapeutic strategies for modulating Hippo signaling dysfunction in CRC. To advance novel therapeutic techniques for CRC, it is imperative to grasp the involvement of the Hippo pathway in CRC and its interaction with alternate signaling pathways, noncoding RNAs, gut microbiota, and the immune microenvironment. This review seeks to illuminate the function and control of the Hippo pathway in CRC, ultimately aiming to unearth innovative therapeutic methodologies for addressing this ailment.

Mitophagy-related long non-coding RNA signature predicts prognosis and drug response in Ovarian Cancer

BACKGROUND

Ovarian cancer (OC) is the most malignant tumor with the worst prognosis in female reproductive system. Mitophagy and long non-coding RNAs (lncRNAs) play pivotal roles in tumorigenesis, development, and drug resistance. The effects of mitophagy-related lncRNAs on OC prognosis and therapeutic response remain unelucidated.

METHODS

We retrieved OC-related RNA sequence, copy number variation, somatic mutation, and clinicopathological information from The Cancer Genome Atlas database and mitophagy-related gene sets from the Reactome database. Pearson's correlation analysis was used to distinguish mitophagy-related lncRNAs. A prognostic lncRNA signature was constructed using UniCox, LASSO, and forward stepwise regression analysis. Individuals with a risk score above or below the median were classified as high- or low-risk groups, respectively. The risk model was analyzed using the Kaplan-Meier estimator, receiver operating characteristic curve, decision curve analysis, and Cox regression analysis and validated using an internal dataset. LINC00174 was validated in clinical samples and OC cell lines. We also reviewed reports on the role of LINC00174 in cancer. Subsequently, a nomogram model was constructed. Furthermore, the Genomics of Drug Sensitivity in Cancer database was used to explore the relationship between the risk model and anti-tumor drug sensitivity. Gene set variation analysis was performed to assess potential differences in biological functions between the two groups. Finally, a lncRNA prognostic signature-related competing endogenous RNA (ceRNA) network was constructed.

RESULTS

The prognostic signature showed that patients in the high-risk group had a poorer prognosis. The nomogram exhibited satisfactory accuracy and predictive potential. LINC00174 mainly acts as an oncogene in cancer and is upregulated in OC; its knockdown inhibited the proliferation and migration, and promoted apoptosis of OC cells. High-risk patients were more insensitive to cisplatin and olaparib than low-risk patients. The ceRNA network may help explore the potential regulatory mechanisms of lncRNAs.

CONCLUSION

The mitophagy-related lncRNA signature can help estimate the survival and drug sensitivity, the ceRNA network may provide novel therapeutic targets for patients with OC.

Expression of LINC00174 in different cancers: Review of the literature and bioinformatics analyses

LINC00174 is an example of long intergenic non-coding RNAs with important functions in the development of human cancers. The gene encoding this lincRNA is located on 7q11.21. LINC00174 has been demonstrated to play an oncogenic role in a variety of cancers, including colorectal carcinoma, thymic carcinoma, glioma, glioblastoma, hepatocellular carcinoma, kidney renal clear cell carcinoma, breast cancer and non-functioning pituitary adenoma. In lung cancer, there is an obvious discrepancy between different studies regarding the role of this lincRNA. This lincRNA is also involved in the determination of prognosis of different cancers, particularly colorectal cancer. In the current review, we discuss the role of this lincRNA in human carcinogenesis based on the available data in the literature and bioinformatics tools.

LINC00174 Promotes Colon Cancer Progression by Regulating Inflammation and Glycolysis by Targeting the MicroRNA-2467-3p/Enolase 3 Axis

OBJECTIVE

To elucidate the mechanism by which LINC00174 promotes colon cancer progression by targeting the microRNA-2467-3p (miR-2467-3p)/enolase 3 (ENO3) axis to regulate inflammation and glycolysis.

METHODS

The expression of LINC00174 and ENO3 in colon cancer tissues, its relationship with survival rate, and correlation were analyzed using bioinformatic analysis. The effects of LINC00174 overexpression and silencing on the biological behavior of and inflammation in colon cancer cells were analyzed via transfection experiments. The target relationships between miR-2467-3p or LINC00174 and ENO3 were verified using sequence prediction and the dual-luciferase reporter assay, respectively. Furthermore, LINC00174- and/or miR-2467-3p-overexpressing cells were prepared to determine the effects on ENO3 protein levels and glycolysis. Finally, the effects of LINC00174 and/or miR-2467-3p overexpression on colon cancer, ENO3 protein levels, and inflammation were analyzed using a tumor-bearing mice model.

RESULTS

LINC00174 and ENO3 were overexpressed and associated with a lower survival rate. LINC00174 was positively correlated with ENO3 in colon cancer tissues. Furthermore, the overexpression of LINC00174 in colon cancer cell lines promoted the proliferation, migration, and invasion of colon cancer cells and inflammation but inhibited apoptosis. The overexpression of miR-2467-3p inhibited ENO3 protein levels, which was attenuated via LINC00174 overexpression. Furthermore, it inhibited the biological behavior of and inflammation and glycolysis in colon cancer cells and blocked their LINC00174-induced promotion. Moreover, using animal experiments, the regulatory effects of LINC00174 on tumor growth, ENO3 protein levels, and inflammation via miR-2467-3p were confirmed.

CONCLUSION

LINC00174 promotes the glycolysis, inflammation, proliferation, migration, and invasion of colon cancer cells and inhibits apoptosis. The cancer-promoting mechanism of LINC00174 is related to targeting miR-2467-3p to promote ENO3 protein levels.

linc00174 deteriorates the pathogenesis of diabetic retinopathy via miR-26a-5p/PTEN/Akt signalling cascade-mediated pyroptosis

PURPOSE

We aim to investigate the potential role and underlying mechanisms of linc00174 on pyroptosis in the pathogenesis of DR.

METHODS

Expression patterns of linc00174, miR-26a-5p and PTEN in human retinal microvascular endothelial cells (hRMECs) were detected by quantitative real-time PCR (qRT-PCR) and Western blot, respectively. Biological functions of linc00174 on cell proliferation and pyroptosis were evaluated by CCK-8, flow cytometry, caspase-1 activity assays, respectively. Luciferase reporter assay was employed to verify the interaction between miR-26a-5p and linc00174/PTEN. Streptozotocin (STZ)-induced DR in mice was further constructed to verify the potential role of linc00174 in vivo. Hematoxylin and eosin (H&E) and immunohistochemical staining were performed to assess the pathological changes and caspase-1 expression in retinal tissues.

RESULTS

Up-regulated linc00174 and PTEN and down-regulated miR-26a-5p were uncovered in hRMECs treated with high glucose (HG). Mechanistically, linc00174 served as a sponge of miR-26a-5p to facilitate PTEN expression. Functionally, knockdown of linc00174 inhibited HG-induced pyroptosis of hRMECs via targeting miR-26a-5p. Moreover, linc00174/miR-26a-5p axis participated in HG-induced pyroptosis via PTEN/Akt signaling cascade. Further, silencing of linc00174 attenuated pyroptosis via regulating miR-26a-5p/PETN axis in DR mice.

CONCLUSIONS

Collectively, our study reveals that linc10074 deteriorates the pathogenesis of DR via miR-26a-5p/PTEN/Akt signalling cascade, which may shed light on the discovery of potential therapeutic agents for DR treatment.

Long Intergenic Nonprotein Coding RNA 00174 Aggravates Lung Squamous Cell Carcinoma Progression via MicroRNA-185-5p/Nuclear Factor IX axis

Extensive studies have presented that long noncoding RNAs (lncRNAs) are closely implicated in the pathogenesis of various human malignancies, including lung squamous cell carcinoma (LUSC). This study explored the biological role and the underlying mechanism of long intergenic nonprotein coding RNA 00174 (LINC00174) in LUSC. LINC00174 expression was measured by reverse transcription quantitative real-time polymerase chain reaction (RT-qPCR). Both in vitro and in vivo experiments were conducted to determine LINC00174 function in LUSC. Mechanical assays were performed to investigate the molecular mechanism involving LINC00174 and related genes. LINC00174 expression was high in LUSC cells. Silencing of LINC00174 could restrain LUSC cells proliferation, migration, and invasion while promoting cell apoptosis. Mechanically, LINC00174 could interact with miR-185-5p to upregulate nuclear factor IX (NFIX), which was the direct target gene of miR-185-5p. Notably, NFIX elevation could rescue the repressing effect of LINC00174 silence on LUSC cell malignant behaviors. Our data suggested that LINC00174 aggravated LUSC progression via serving as a competing endogenous RNA (ceRNA) to sponge miR-185-5p and ultimately upregulate NFIX, which offered a promising novel target for LUSC therapy.

The interplay between noncoding RNA and YAP/TAZ signaling in cancers: molecular functions and mechanisms

The Hippo signaling pathway was found coordinately modulates cell regeneration and organ size. Its dysregulation contributes to uncontrolled cell proliferation and malignant transformation. YAP/TAZ are two critical effectors of the Hippo pathway and have been demonstrated essential for the initiation or growth of most tumors. Noncoding RNAs (ncRNAs), including miRNAs, lncRNAs, and circRNAs, have been shown to play critical roles in the development of many cancers. In the past few decades, a growing number of studies have revealed that ncRNAs can directly or indirectly regulate YAP/TAZ signaling. YAP/TAZ also regulate ncRNAs expression in return. This review summarizes the interactions between YAP/TAZ signaling and noncoding RNAs together with their biological functions on cancer progression. We also try to describe the complex feedback loop existing between these components.

Discovery of New Therapeutic Targets for Osteosarcoma Treatment Based on Immune-Related lncRNAs in the Tumor Microenvironment

Background

Long noncoding RNAs (lncRNAs) play an important role in osteosarcoma development, but their role in the tumor microenvironment (TME) is not fully understood. This study associated lncRNAs with immune-related genes and explored the mechanism of lncRNAs in osteosarcoma progression.

Methods

Unsupervised consensus clustering was applied to construct immune subtypes based on immune-related lncRNAs identified by Pearson's correlation analysis. A series of functional analysis was performed to reveal the links among lncRNAs, immune subtypes, TME, and osteosarcoma prognosis.

Results

We identified two immune subtypes C1 and C2 showing distinct overall survival. ECM-receptor interaction pathway was more activated in C2 subtype, while immune response pathways were more enriched in C2 subtype. Differential TME and response to chemotherapeutic drugs were observed between the two subtypes. Four metagenes of costimulation, cytolytic activity (CYT), immune score, and STAT1 were differentially enriched in the two subtypes. Based on 26-paired lncRNAs, we constructed a 4-paired lncRNA prognostic signature for predicting prognosis of osteosarcoma prognosis.

Conclusions

This study focused on immune-related lncRNAs and TME, showing the possible role and mechanisms of lncRNAs in tumor growth and metastasis. ECM may be the new therapeutic target for treating osteosarcoma, and 26-paired lncRNAs could serve as a basis for further studying the mechanisms of CYT and STAT1 in immune response, cancer cell proliferation, and migration. The two subtypes and prognostic signature could promote the design of personalized osteosarcoma treatment.

Dexmedetomidine promotes cell proliferation and inhibits cell apoptosis by regulating LINC00982 and activating the phosphoinositide-3-kinase (PI3K)/protein kinase B (AKT) signaling in hypoxia/reoxygenation-induced H9c2 cells

Previous studies showed dexmedetomidine (DEX) could alleviate myocardial ischemia/reperfusion injury (MIRI). Nevertheless, the mechanisms by which DEX alleviated MIRI remain to be determined. Our results demonstrated that DEX reversed hypoxia/reoxygenation (H/R)-induced decreased proliferation, and enhanced LINC00982 level, apoptosis, and inflammation in H9c2 cells. Moreover, LINC00982 overexpression attenuated the DEX-mediated protective effect of H9c2 cells under H/R. In addition, DEX upregulated p-phosphoinositide-3-kinase (p-PI3K) and p-protein kinase B (p-AKT) levels, and the silencing of LINC00982 further enhanced this effect in H/R-induced H9c2 cells. Furthermore, LINC00982 deletion enhanced the protective effect of DEX on H9c2 cells under H/R condition, while PI3K inhibitor, LY294002, obviously reversed this phenomenon. In sum, our work determined that DEX could suppress cell apoptosis and inflammation in H/R-triggered H9c2 through downregulating LINC00982 and activating PI3K/AKT signaling.

Downregulated long intergenic non-coding RNA 00,174 represses malignant biological behaviors of lung cancer cells by regulating microRNA-584-3p/ribosomal protein S24 axis

The detailed regulatory mechanism of LINC00174 in lung cancer (LC) development remains largely unknown. This research was designed to probe into the impacts of LINC00174 in LC cells through modulating the microRNA (miR)-584-3p/ribosomal protein S24 (RPS24) axis. LINC00174, miR-584-3p, and RPS24 expression levels in LC cells and tissues were examined. The constructs altering LINC00174, miR-584-3p, or RPS24 expression were transfected into LC cells to examine the malignant phenotypes of LC cells. The relations among LINC00174, miR-584-3p, and RPS24 were validated. LINC00174 and RPS24 were high-expressed while miR-584-3p was low-expressed in LC. Downregulated LINC00174 or RPS24 or upregulated miR-584-3p inhibited the malignant biological behaviors of LC cells. The silenced miR-584-3p could reverse the repressive effects of reduced LINC00174 on the development of LC cells; while RPS24 overexpression inverted the repressive effects of miR-584-3p elevation on LC cells. Mechanically, LINC00174 bound to miR-584-3p that targeted RPS24. Repressed LINC00174 can relieve the malignant phenotypes of LC cells via modulating the miR-584-3p/RPS24 axis.

STAT1 mediated long non-coding RNA LINC00504 influences radio-sensitivity of breast cancer via binding to TAF15 and stabilizing CPEB2 expression

Radiotherapy plays important roles in the treatment of breast cancer (BC), which develops from malignant cells in the breast. Long non-coding RNAs (lncRNAs) have been reported to be implicated in radio-resistance or radio-sensitivity of human cancer, which includes breast cancer. Nevertheless, long intergenic non-protein coding RNA 0504 (LINC00504) has not been investigated in BC. In our study, from RT-qPCR analysis, LINC00504 was found to be up-regulated in BC cells. By conducting in vitro assays, it was confirmed that the knockdown of LINC00504 could enhance the radio-sensitivity of BC cells. The regulatory mechanism of LINC00504 in BC was also verified by chromatin immunoprecipitation (ChIP), RNA immunoprecipitation (RIP) and luciferase reporter assays. From the experimental results, we knew that the up-regulation of LINC00504 was mediated by signal transducer and activator of transcription 1 (STAT1). Moreover, LINC00504 stabilized the expression of cytoplasmic polyadenylation element-binding protein 2 (CPEB2) via binding to TATA-box binding protein associated factor 15 (TAF15). Furthermore, rescue assays validated that LINC00504 participated in regulating the radio-sensitivity of BC cells via up-regulating CPEB2. In summary, our study disclosed that STAT1 could mediate LINC00504 and weaken the radio-sensitivity of BC cells via binding to TAF15 and stabilizing CPEB2 expression.

A Novel Prognostic Prediction Model for Colorectal Cancer Based on Nine Autophagy-Related Long Noncoding RNAs

Introduction

Colorectal cancer (CRC) is the most common gastrointestinal cancer and has a low overall survival rate. Tumor–node–metastasis staging alone is insufficient to predict patient prognosis. Autophagy and long noncoding RNAs play important roles in regulating the biological behavior of CRC. Therefore, establishing an autophagy-related lncRNA (ARlncRNA)-based bioinformatics model is important for predicting survival and facilitating clinical treatment.

Methods

CRC data were retrieved from The Cancer Genome Atlas. The database was randomly divided into train set and validation set; then, univariate and multivariate Cox regression analyses were performed to screen prognosis-related ARlncRNAs for prediction model construction. Interactive network and Sankey diagrams of ARlncRNAs and messenger RNAs were plotted. We analyzed the survival rate of high- and low-risk patients and plotted survival curves and determined whether the risk score was an independent predictor of CRC. Receiver operating characteristic curves were used to evaluate model sensitivity and specificity. Then, the expression level of lncRNA was detected by quantitative real-time polymerase chain reaction, and the location of lncRNA was observed by fluorescence in situ hybridization. Additionally, the protein expression was detected by Western blot.

Results

A prognostic prediction model of CRC was built based on nine ARlncRNAs (NKILA, LINC00174, AC008760.1, LINC02041, PCAT6, AC156455.1, LINC01503, LINC00957, and CD27-AS1). The 5-year overall survival rate was significantly lower in the high-risk group than in the low-risk group among train set, validation set, and all patients (all p < 0.001). The model had high sensitivity and accuracy in predicting the 1-year overall survival rate (area under the curve = 0.717). The prediction model risk score was an independent predictor of CRC. LINC00174 and NKILA were expressed in the nucleus and cytoplasm of normal colonic epithelial cell line NCM460 and colorectal cancer cell lines HT29. Additionally, LINC00174 and NKILA were overexpressed in HT29 compared with NCM460. After autophagy activation, LINCC00174 expression was significantly downregulated both in NCM460 and HT29, while NKILA expression was significantly increased.

Conclusion

The new ARlncRNA-based model predicts CRC patient prognosis and provides new research ideas regarding potential mechanisms regulating the biological behavior of CRC. ARlncRNAs may play important roles in personalized cancer treatment.

Epigenetic Regulation of the Wnt/β-Catenin Signaling Pathway in Cancer

Studies over the past four decades have elucidated the role of Wnt/β-catenin mediated regulation in cell proliferation, differentiation and migration. These processes are fundamental to embryonic development, regeneration potential of tissues, as well as cancer initiation and progression. In this review, we focus on the epigenetic players which influence the Wnt/β-catenin pathway via modulation of its components and coordinated regulation of the Wnt target genes. The role played by crosstalk with other signaling pathways mediating tumorigenesis is also elaborated. The Hippo/YAP pathway is particularly emphasized due to its extensive crosstalk via the Wnt destruction complex. Further, we highlight the recent advances in developing potential therapeutic interventions targeting the epigenetic machinery based on the characterization of these regulatory networks for effective treatment of various cancers and also for regenerative therapies.

A Positive Feedback Loop of lncRNA MIR31HG-miR-361-3p -YY1 Accelerates Colorectal Cancer Progression Through Modulating Proliferation, Angiogenesis, and Glycolysis

Background

Colorectal cancer (CRC) is a common malignant tumor with high metastatic and recurrent rates. This study probes the effect and mechanism of long non-coding RNA MIR31HG on the progression of CRC cells.

Materials and Methods

Quantitative real-time PCR (qRT-PCR) was used to analyze the expression of MIR31HG and miR-361-3p in CRC tissues and normal tissues. Gain- or loss-of-function assays were conducted to examine the roles of MIR31HG, miR-361-3p and YY1 transcription factor (YY1) in the CRC progression. 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, and colony formation experiment were conducted to test CRC cell proliferation. CRC cell invasion was determined by Transwell assay. The glucose detection kit and lactic acid detection kit were utilized to monitor the levels of glucose and lactate in CRC cells. The glycolysis level in CRC cells was examined by the glycolytic stress experiment. Western blot was performed to compare the expression of glycolysis-related proteins (PKM2, GLUT1 and HK2) and angiogenesis-related proteins (including VEGFA, ANGPT1, HIF1A and TIMP1) in HUVECs. The binding relationships between MIR31HG and miR-361-3p, miR-361-3p and YY1 were evaluated by the dual-luciferase reporter assay and RNA immunoprecipitation (RIP).

Results

MIR31HG was up-regulated in CRC tissues and was associated with poorer prognosis of CRC patients. The in-vitro and in-vivo experiments confirmed that overexpressing MIR31HG heightened the proliferation, growth, invasion, glycolysis and lung metastasis of CRC cells as well as the angiogenesis of HUVECs. In addition, MIR3HG overexpression promoted YY1 mRNA and protein level, and forced overexpression of YY1 enhanced MIR31HG level. Overexpressing YY1 reversed the tumor-suppressive effect mediated by MIR31HG knockdown. miR-361-3p, which was inhibited by MIR31HG overexpression, repressed the malignant behaviors of CRC cells. miR-361-3p-mediated anti-tumor effects were mostly reversed by upregulating MIR31HG. Further mechanism studies illustrated that miR-361-3p targeted and negatively regulated the expression of YY1.

Conclusion

This study reveals that MIR31HG functions as an oncogenic gene in CRC via forming a positive feedback loop of MIR31HG-miR-361-3p-YY1.

LINC00174 Facilitates Proliferation and Migration of Colorectal Cancer Cells via MiR-3127-5p/ E2F7 Axis

The literature indicates that LINC00174 promotes the growth of colorectal cancer (CRC) cells, but its research needs to be enriched. We tried to explore the function and mechanism of LINC00174 in CRC cell proliferation and migration. Bioinformatics analysis predicted the binding relationship and expressions of lncRNA, miRNA and mRNA. Clinical study analyzes the relationship between LINC00174 and clinical data characteristics of CRC patients. The expressions of LINC00174, miR-3127-5p and E2F7 were verified by RT-qPCR, and the combination of the two was verified by dual luciferase analysis and RNA immunoprecipitation as needed. Western blot was used to detect the expression of EMT-related protein and E2F7 protein. Functional experiments were used to evaluate the function of the target gene on CRC cells. LINC00174 was up-regulated in CRC clinical samples and cells and was related to the clinical characteristics of CRC patients. High-expression of LINC00174, contrary to the effect of siLINC00174, promoted cell viability, proliferation, migration and invasion, up-regulated the expressions of N-Cadherin, Vimentin, E2F7, and inhibited the expression of E-Cadherin. MiR-3127-5p was one of the targeted miRNAs of LINC00174 and was down-regulated in CRC samples. In addition, miR-3127-5p mimic partially reversed the malignant phenotype of CRC cells induced by LINC00174. Besides, E2F7 was a target gene of miR-3127-5p, and LINC00174 repressed miR-3127-5p to regulate E2F7. Our research reveals that LINC00174 affected the biological characteristics of CRC cells through regulated miR-3127-5p/ E2F7 axis.

LINC00174 Facilitates Cell Proliferation, Cell Migration and Tumor Growth of Osteosarcoma via Regulating the TGF-β/SMAD Signaling Pathway and Upregulating SSH2 Expression

Osteosarcoma (OS), a frequent malignant tumor which mainly occurs in the bone. The roles of long noncoding RNAs (lncRNAs) have been revealed in cancers, including OS. LncRNA long intergenic non-protein coding RNA (LINC00174) has been validated as an oncogene in several cancers. However, the role of LINC00174 in OS has not been explored. In our research, loss-of-function assays were conducted to explore the function of LINC00174 in OS cells. Then, we explored the downstream pathway of LINC00174 in OS cells. Bioinformatics, RNA pull-down and RIP experiments investigated the downstream mechanism of LINC00174 in OS cells. Finally, in vivo assays clarified the effect of LINC00174 on tumorigenesis. We found that LINC00174 was upregulated in OS tissues and cells. LINC00174 knockdown repressed OS cell growth. Mechanistically, LINC00174 knockdown suppressed the TGF-β/SMAD pathway. LINC00174 interacted with miR-378a-3p, and slingshot protein phosphatase 2 (SSH2) 3′UTR was targeted by miR-378a-3p in OS cells. Rescue assays showed that SSH2 upregulation or miR-378a-3p inhibition counteracted the inhibitory effect of LINC00174 depletion in OS cell growth. Additionally, LINC00174 depletion suppressed tumor growth in mice. In conclusion, LINC00174 promotes OS cellular malignancy and tumorigenesis via the miR-378a-3p/SSH2 axis and the TGF-β/SMAD pathway, which might provide a novel insight for OS treatment.

A novel regulatory network of linc00174/miR-150-5p/VEGFA modulates pathological angiogenesis in diabetic retinopathy

BACKGROUND

Diabetic retinopathy (DR) has been regarded as a sight-threatening vascular complication of diabetes mellitus (DM). Accumulating evidence has identified the involvement of long non-coding RNAs (lncRNAs) in DR pathogenesis. We aim to investigate the role and underlying mechanism of linc00174 in DR process.

METHODS

Samples of human vitreous humour from proliferative DR and non-diabetic individuals were collected to examine the levels of linc00174. Human retinal microvascular endothelial cells (HRMECs) exposed with high glucose were employed to simulate the pathological statues of DR. shRNA specifically targeting linc00174 was applied. CCK-8, transwell, and matrigel tube formation were performed to evaluate cell proliferation, migration and angiogenesis. Bioinformatics analysis and luciferase reporter assay were conducted to verify the linc00174/miR-150-5p/VEGFA regulatory network. Western blotting was employed to determine the expression of VEGFA.

RESULTS

Linc00174 was significantly elevated in patients with DR, as well as HG-stimulated HRMECs, of which knockdown repressed HG-induced proliferation, migration and angiogenesis. miR-150-5p was identified as a downstream effector to be involved in linc00174-mediated protective effects. miR-150-5p directly bound to the 3'-UTR of VEGFA. The linc00174/miR-150-5p/VEGFA axis was confirmed in retinal vascular dysfunction.

CONCLUSION

Linc00174 deteriorates diabetic retinal microangiopathy via regulating miR-150-5p/VEGFA pathway, indicating a novel therapeutic target for DR treatment.

The Role of non-coding RNAs in colorectal cancer, with a focus on its autophagy

Colorectal cancer (CRC) is one of malignant afflictions burdening people worldwide, mainly caused by shortages of effective medical intervention and poorly mechanistic understanding of the pathogenesis of CRC. Non-coding RNAs (ncRNAs) are a type of heterogeneous transcripts without the capability of coding protein, but have the potency of regulating protein-coding gene expression. Autophagy is an evolutionarily conserved catabolic process in which cytoplasmic contents are delivered to cellular lysosomes for degradation, resulting in the turnover of cellular components and producing energy for cell functions. A growing body of evidence reveals that ncRNAs, autophagy, and the crosstalks of ncRNAs and autophagy play intricate roles in the initiation, progression, metastasis, recurrence and therapeutic resistance of CRC, which confer ncRNAs and autophagy to serve as clinical biomarkers and therapeutic targets for CRC. In this review, we sought to delineate the complicated roles of ncRNAs, mainly including miRNAs, lncRNAs and circRNAs, in the pathogenesis of CRC, particularly focus on the regulatory role of ncRNAs in CRC-related autophagy, attempting to shed light on the complex pathological mechanisms, involving ncRNAs and autophagy, responsible for CRC tumorigenesis and development, so as to underpin the ncRNAs- and autophagy-based therapeutic strategies for CRC in clinical setting.

LINC00174 is a favorable prognostic biomarker in glioblastoma via promoting proliferative phenotype

OBJECTIVE

To investigate the expression pattern, prognostic value and biological functional of LINC00174 in glioma.

METHODS

In total, 140 glioma samples were collected as discovery cohort. TCGA RNA sequence dataset was obtained as validation set. Kaplan-Meier survival and multivariate Cox analysis were performed to evaluate survival difference. Furthermore, the biological function of LINC00174 was analyzed by clonogenic and intracranial tumor model assays.

RESULTS

Overexpressed LINC00174 was significantly correlated with tumor grade as well as the higher mortality in survival analysis both in the discovery and the validation GBM cohorts. Besides, LINC00174 served as an independent prognostic indicator in glioblastoma patients. Additionally, knock down of LINC00174 expression significantly suppressed GBM cells' proliferation both in vitro and vivo.

CONCLUSION

LINC00174 acts as an oncogene in glioma and may be a new potential therapeutic target.

Exosomal LINC00174 derived from vascular endothelial cells attenuates myocardial I/R injury via p53-mediated autophagy and apoptosis

In this study, we aim to investigate the regulation of specific long non-coding RNAs (lncRNAs) on the progression of ischemia/reperfusion (I/R) injury. We identified and characterized the exosomes derived from mouse primary aortic endothelial cells. Subsequently, we found that these exosomes expressed typical exosomal markers and high levels of LINC00174, which significantly ameliorated I/R-induced myocardial damage and suppressed the apoptosis, vacuolation, and autophagy of myocardial cells. Mechanistic approaches revealed that LINC00174 directly interacted with SRSF1 to suppress the expression of p53, thus restraining the transcription of myocardin and repressing the activation of the Akt/AMPK pathway that was crucial for autophagy initiation in I/R-induced myocardial damage. Moreover, this molecular mechanism was verified by in vivo study. In summary, exosomal LINC00174 generated from vascular endothelial cells repressed p53-mediated autophagy and apoptosis to mitigate I/R-induced myocardial damage, suggesting that targeting LINC00174 may be a novel strategy to treat I/R-induced myocardial infarction.

FOXO3-induced lncRNA LOC554202 contributes to hepatocellular carcinoma progression via the miR-485-5p/BSG axis

Long non-coding RNAs (LncRNAs) have played very important roles in the malignancy behaviors of hepatocellular carcinoma (HCC). LncRNA LOC554202 (LOC554202) was a newly identified tumor-related lncRNA. However, its expression and function in HCC remained unknown. In this study, we firstly reported that LOC554202 expression was distinctly upregulated in HCC specimens and cell lines. Clinical assays indicated that increased LOC554202 expression had a diagnostic value for HCC patients and was positively associated with advanced stages and poor clinical prognosis. Additionally, forkhead box O3(FOXO3) could bind directly to the LOC554202 promoter region and activate its transcription. Functionally, we observed that knockdown of LOC554202 suppressed the proliferation, migration, invasion, and epithelial–mesenchymal transition (EMT) progress of HCC cells, and promoted apoptosis. Mechanistically, LOC554202 competitively bound to miR-485-5p and prevented the suppressive effects of miR-485-5p on its target gene basigin (BSG), which finally led to HCC metastasis, EMT, and docetaxel chemoresistance. Our data demonstrated that FOXO3-induced LOC554202 contributed to HCC progression by upregulating BSG via competitively binding to miR-485-5p, which suggested that the regulation of the FOXO3/LOC554202/miR-485-5p/BSG axis may have beneficial effects in the treatment of HCC.

STAT1-induced regulation of lncRNA ZFPM2-AS1 predicts poor prognosis and contributes to hepatocellular carcinoma progression via the miR-653/GOLM1 axis

Long noncoding RNAs (lncRNAs) have drawn growing attention owing to their important effects in various tumors, including hepatocellular carcinoma (HCC). Recently, a newly identified lncRNA, ZFPM2 antisense RNA 1 (ZFPM2-AS1), was reported to serve as an oncogene in gastric cancer. However, its function in tumors remains largely unknown. In this study, we identified ZFPM2-AS1 as a novel HCC-related lncRNA, which was observed to be distinctly upregulated in HCC tissues and associated with shorter overall survival. Luciferase reporter and chromatin immunoprecipitation assays suggested that overexpression of ZFPM2-AS1 was induced by STAT1. Functional investigations suggested that the inhibition of ZFPM2-AS1 suppressed cell proliferation, metastasis, cell cycle progression while accelerated cell apoptosis. Mechanistic studies showed that there were two binding sites of miR-653 within the sequence of ZFPM2-AS1 and the levels of ZFPM2-AS1 were negatively correlated with miR-653. In addition, ZFPM2-AS1 could reverse the suppressor effects of miR-653 on the proliferation and metastasis of HCC cells by the modulation of GOLM1, a target gene of miR-653. To conclude, we provided a better understanding of the interaction mechanism between ZFPM2-AS-miR-653-GOLM1 axis, which may help develop prognostic biomarkers and therapeutic target for HCC.

LINC00174 is a novel prognostic factor in thymic epithelial tumors involved in cell migration and lipid metabolism

Long non-coding RNAs are emerging as new molecular players involved in many biological processes, such as proliferation, apoptosis, cell cycle, migration, and differentiation. Their aberrant expression has been reported in variety of diseases. The aim of this study is the identification and functional characterization of clinically relevant lncRNAs responsible for the inhibition of miR-145-5p, a key tumor suppressor in thymic epithelial tumors (TETs). Starting from gene expression analysis by microarray in a cohort of fresh frozen thymic tumors and normal tissues, we identified LINC00174 as upregulated in TET. Interestingly, LINC00174 expression is positively correlated with a 5-genes signature in TETs. Survival analyses, performed on the TCGA dataset, showed that LINC00174 and its associated 5-genes signature are prognostic in TETs. Specifically, we show that LINC00174 favors the expression of SYBU, FEM1B, and SCD5 genes by sponging miR-145-5p, a well-known tumor suppressor microRNA downregulated in a variety of tumors, included TETs. Functionally, LINC00174 impacts on cell migration and lipid metabolism. Specifically, SCD5, one of the LINC00174-associated genes, is implicated in the control of lipid metabolism and promotes thymic cancer cells migration. Our study highlights that LINC00174 and its associated gene signature are relevant prognostic indicators in TETs. Of note, we here show that a key controller of lipid metabolism, SCD5, augments the migration ability of TET cells, creating a link between lipids and motility, and highlighting these pathways as relevant targets for the development of novel therapeutic approaches for TET.

Long non-coding RNA MCF2L-AS1 promotes the aggressiveness of colorectal cancer by sponging miR-874-3p and thereby up-regulating CCNE1

BACKGROUND

Long non-coding RNAs (lncRNAs) have drawn growing attention because of the role which they play in various diseases, including colorectal cancer (CRC). However, the potential functions of lncRNA MCF2L antisense RNA 1 (MCF2L-AS1) in tumors remained largely unclear. The present study aimed to explore the clinical significance and the biological effects of lncRNA MCF2L antisense RNA 1 (MCF2L-AS1) in CRC.

METHODS

Reverse transcriptase-polymerase chain reaction was performed to determine the expression of MCF2L-AS1 in CRC. The clinical significance of MCF2L-AS1 in CRC patients was analyzed statistically. In vitro experiments were performed to determine the effects of MCF2L-AS1 on the cellular progression of CRC cells. Bioinformatic assays, luciferase reporter assays and RNA-pulldown assays were performed to predict for potential microRNAs that can interact with MCF2L-AS1 and mRNAs that can interact with miR-874-3p.

RESULTS

We identified a novel CRC-related lncRNA, MCF2L-AS1, which is distinctly highly expressed in CRC. Its diagnostic value for CRC patients was also demonstrated. Clinical assays revealed that high MCF2L-AS1 expression is associated with advanced stages, positive metastasis and the poor prognosis of CRC patients. Multivariate assays confirmed that MCF2L-AS1 expression is an independent poor prognostic factor for both 5-year overall survival and 5-year disease-free survival of CRC patients. Functionally, we confirmed that knockdown of MCF2L-AS1 distinctly suppresses the proliferation, migration and invasion of CRC cells and also promotes apoptosis. Mechanistic investigation showed that MCF2L-AS1 functions as an endogenous sponge for miR-874-3p to increase the expression of CCNE1.

CONCLUSIONS

Our findings identified a novel CRC-related lncRNA, MCF2L-AS1, which may be used as a potential diagnostic and prognostic biomarker for CRC patients. In addition, the newly identified MCF2L-AS1/miR-874-3p/CCNE1 axis can modulate the initiation and progression of CRC.

YY1-mediated up-regulation of lncRNA LINC00466 facilitates glioma progression via miR-508/CHEK1

BACKGROUND

The abnormal expression of lncRNA LINC00466 (LINC00466) has been demonstrated in several tumor types. However, the expression pattern and functions of LINC00466 in glioma remain uninvestigated.

METHODS

A reverse transcriptase-polymerase chain reaction (RT-PCR) was utilized to analyze LINC00466 in human glioma tissues and cell lines. Luciferase reporter assays were performed to explore whether YY1 could bind to the promoter region of LINC00466. Cell counting kit-8, flow cytometry, colony-formation, transwell migration and invasion assays were carried out to determine the involvement of INC00466 in glioma. Luciferase assays and pulldown assays were conducted to verify the binding sites.

RESULTS

We report that LINC00466 expression is increased in glioma cells and tissues. YY1 transcription factor (YY1) can bind directly to the LINC00466 promoter region. Clinical studies revealed that the elevated expression of LINC00466 is closely correlated with an advanced World Health Organization grade (p = 0.008), Karnofsky Performance Status score (p = 0.004) and a short overall survival (p = 0.0035) of glioma patients. Functional assays revealed that LINC00466 knockdown distinctly suppresses glioma cell proliferation, migration, invasion and epithelial-mesenchymal progress, and also promotes apoptosis. Moreover, dual-luciferase reporter assays indicated that LINC00466 acts as an endogenous sponge via binding to miR-508 and decreasing its expression. Luciferase assays and RT-PCR assays demonstrated that checkpoint kinase 1 (CHEK1) is a target of miR-508, and LINC00466 modulates CHEK1 levels by competing for miR-508. LINC00466 may exhibit its anti-oncogenic roles through targeting the miR-508/CHEK1 axis.

CONCLUSIONS

Our findings identified a novel glioma-related long non-coding RNA, LINC00466, which may provide a potential novel prognostic and therapeutic target for glioma.

Yin Yang 1-induced LINC00667 up-regulates pyruvate dehydrogenase kinase 1 to promote proliferation, migration and invasion of cholangiocarcinoma cells by sponging miR-200c-3p

Cholangiocarcinoma (CCA) is one of the most aggressive and lethal malignancies. Long noncoding RNAs (lncRNAs) are being found to play crucial roles in CCA progression. This work aims to investigate the roles of long intergenic non-protein coding RNA 667 (LINC00667) in progression of CCA. RT-qPCR and western blot were applied to detect gene expression. Clinical correlation and survival were analyzed by statistical methods. Overexpression and RNA interference approaches were used to investigate the effects of LINC00667 on CCA cells. Tumor xenograft assay was performed to detect the function of LINC00667 in vivo. Transcriptional regulation and competing endogenous RNA (ceRNA) mechanism were predicted via bioinformatics analysis. ChIP, luciferase reporter, and Ago2 RIP assays further confirmed the predicted results. Our data indicated that LINC00667 was highly expressed in CCA tissues and cells, and transcription factor Yin Yang 1 (YY1) induced LINC00667 expression in CCA cells. Up-regulated LINC00667 was significantly associated with lymph node metastasis, advanced TNM stage, and poor prognosis. Knockdown of LINC00667 suppressed the proliferation, migration, invasion and epithelial-mesenchymal transition (EMT) of CCA cells, while overexpression of LINC00667 acquired opposite effects. Moreover, knockdown of LINC00667 inhibited tumor growth in vivo. In addition, LINC00667 was demonstrated to function as a ceRNA for miR-200c-3p, and then LINC00667 up-regulated pyruvate dehydrogenase kinase 1 (PDK1) to promote CCA development by inhibiting miR-200c-3p. These findings identified a pivotal role of LINC00667 in tumorigenesis and development of CCA. Targeting the YY1/LINC00667/miR-200c-3p/PDK1 axis may provide a new therapeutic strategy for CCA treatment.

Promotion of BZW2 by LINC00174 through miR-4500 inhibition enhances proliferation and apoptosis evasion in laryngeal papilloma

Background

We aimed to explore the roles of basic leucine zipper and W2 domains (BZW) 2 in the human papillomavirus-infected laryngeal papillomatosis.

Methods

In the present study, BZW 2 knockdown and overexpressed cell lines were constructed. CCK-8 and colony formation assays were used to determine cell proliferation. Caspase-3 activity and nucleosomes fragmentation assays were used to determine cell apoptosis. qRT-PCR and Western blot were employed to evaluate the mRNA and protein levels of target genes, respectively. Luciferase and biotin-coupled miRNA pulldown assays were used to examine the interactions between mRNA and mRNA.

Results

We observed the levels of BZW2 were up-regulated in the laryngeal papilloma (LP) tissues as compared with adjacent tissues. The knockdown of BZW2 significantly inhibited cell proliferation and promoted cell apoptosis in the LP cells. Additionally, we identified the expressions of BZW2 negatively regulated by miR-4500. Luciferase and biotin-coupled miRNA pulldown assays demonstrated that LINC00174 competed with the BZW2 for binding with miR-4500. Moreover, the results showed that LINC00174/miR-4500/BZW2 axis regulated cell proliferation and apoptosis.

Conclusion

Our results demonstrated that the regulation of LINC00174/miR-4500/BZW2 axis might be used as an effective strategy for treatment of human papillomavirus-infected laryngeal papillomatosis.

The crosstalk between lncRNAs and the Hippo signalling pathway in cancer progression

LncRNAs play a pivotal role in the regulation of epigenetic modification, cell cycle, differentiation, proliferation, migration and other physiological activities. In particular, considerable studies have shown that the aberrant expression and dysregulation of lncRNAs are widely implicated in cancer initiation and progression by acting as tumour promoters or suppressors. Hippo signalling pathway has attracted researchers’ attention as one of the critical cancer‐related pathways in recent years. Increasing evidences have demonstrated that lncRNAs could interact with Hippo cascade and thereby contribute to acquisition of multiple malignant hallmarks, including proliferation, metastasis, relapse and resistance to anti‐cancer treatment. Specifically, Hippo signalling pathway is reported to modulate or be regulated by widespread lncRNAs. Intriguingly, certain lncRNAs could form a reciprocal feedback loop with Hippo signalling. More speculatively, lncRNAs related to Hippo pathway have been poised to become important putative biomarkers and therapeutic targets in human cancers. Herein, this review focuses on the crosstalk between lncRNAs and Hippo pathway in carcinogenesis, summarizes the comprehensive role of Hippo‐related lncRNAs in tumour progression and depicts their clinical diagnostic, prognostic or therapeutic potentials in tumours.

linc00174-EZH2-ZNF24/Runx1-VEGFA Regulatory Mechanism Modulates Post-burn Wound Healing

Preservation of denatured dermis exerts promotive functions in wound healing and improves the appearance and function of skin. Angiogenesis is crucial for wound healing during burn injury. However, the potential molecular mechanism of angiogenesis in the recovery after burn injury remains to be elucidated. Herein, RNA chromatin immunoprecipitation (ChIP) sequencing analysis revealed upregulation of long intergenic non-coding RNA 00174 (linc00174) in the post-burn tissues. linc00174 overexpression promoted angiogenic activities of human umbilical vein endothelial cells (HUVECs) in the heat-denatured cell model, characterized by the promotion of cell proliferation, migration, and tube formation. Mechanistically, linc00174 directly bound to enhancer of zeste homolog 2 (EZH2), thus stimulating the protein level of trimethylation at lysine 27 of histone H3 (H3K27me3). Moreover, inhibition of EZH2 resulted in downregulation of ZNF24 and Runx1, as well as a decline of vascular endothelial growth factor A (VEGFA). Furthermore, EZH2 modulated epigenetic repression of ZNF24 and Runx1 through the promoter of H3K27me3. Additionally, ZNF24 and Runx1 both functioned as transcriptional inhibitors of VEGFA. Taken together, these findings uncover that linc00174 epigenetically inhibits ZNF24 and Runx1 expression through binding to EZH2, thus attenuating the suppression of VEGFA, contributing to the facilitation of angiogenesis during the recovery of heat-denatured endothelial cells.

A potential prognostic prediction model of colon adenocarcinoma with recurrence based on prognostic lncRNA signatures

BACKGROUND

Colon adenocarcinoma (COAD) is one of the common gastrointestinal malignant diseases, with high mortality rate and poor prognosis due to delayed diagnosis. This study aimed to construct a prognostic prediction model for patients with colon adenocarcinoma (COAD) recurrence.

METHODS

Differently expressed RNAs (DERs) between recurrence and non-recurrence COAD samples were identified based on expression profile data from the NCBI Gene Expression Omnibus (GEO) repository and The Cancer Genome Atlas (TCGA) database. Then, recurrent COAD discriminating classifier was established using SMV-RFE algorithm, and receiver operating characteristic curve was used to assess the predictive power of classifier. Furthermore, the prognostic prediction model was constructed based on univariate and multivariate Cox regression analysis, and Kaplan-Meier survival curve analysis was used to estimate this model. Furthermore, the co-expression network of DElncRNAs and DEmRNAs was constructed followed by GO and KEGG pathway enrichment analysis.

RESULTS

A total of 54 optimized signature DElncRNAs were screened and SMV classifier was constructed, which presented a high accuracy to distinguish recurrence and non-recurrence COAD samples. Furthermore, six independent prognostic lncRNAs signatures (LINC00852, ZNF667-AS1, FOXP1-IT1, LINC01560, TAF1A-AS1, and LINC00174) in COAD patients with recurrence were screened, and the prognostic prediction model for recurrent COAD was constructed, which possessed a relative satisfying predicted ability both in the training dataset and validation dataset. Furthermore, the DEmRNAs in the co-expression network were mainly enriched in glycan biosynthesis, cardiac muscle contraction, and colorectal cancer.

CONCLUSIONS

Our study revealed that six lncRNA signatures acted as an independent prognostic biomarker for patients with COAD recurrence.

STAT1-induced upregulation of lncRNA KTN1-AS1 predicts poor prognosis and facilitates non-small cell lung cancer progression via miR-23b/DEPDC1 axis

Several of the thousands of long noncoding RNAs (lncRNAs) have been functionally characterized in various tumors. In this study, we aimed to explore the function and possible molecular mechanism of lncRNA KTN1 antisense RNA 1 (KTN1-AS1) involved in non-small cell lung cancer (NSCLC). We identified a novel NSCLC-related lncRNA, KTN1 antisense RNA 1 (KTN1-AS1) which was demonstrated to be distinctly highly expressed in NSCLC. KTN1-AS1 upregulation was induced by STAT1. Clinical study also suggested that higher levels of KTN1-AS1 were associated with advanced clinical progression and a shorter five-year overall survival. Functionally, loss-of-function assays with in vitro and in vivo experiments revealed that KTN1-AS1 promoted the proliferation, migration, invasion and EMT progress of NSCLC cells, and suppressed apoptosis. Mechanistic studies indicated that miR-23b was a direct target of KTN1-AS1, which functioned as a ceRNA to subsequently facilitate miR-23b’s target gene DEPDC1 expression in NSCLC cells. Rescue experiments confirmed that KTN1-AS1 overexpression could increase the colony formation and migration ability suppressed by miR-23b upregulation in NSCLC cells. Overall, our findings imply that STAT1-induced upregulation of KTN1-AS1 display tumor-promotive roles in NSCLC progression via regulating miR-23b/DEPDC1 axis, suggesting that KTN1-AS1 may be a novel biomarker and therapeutic target for NSCLC patients.

SP1-Induced Upregulation of lncRNA LINC00514 Promotes Tumor Proliferation and Metastasis in Osteosarcoma by Regulating miR-708

Background

Growing studies have suggested the dysregulation of long non-coding RNAs (lncRNAs) in several tumors, including osteosarcoma (OS). However, limited studies report metastasis-associated lncRNAs in OS. Our present study aimed to explore the roles of lncRNA LINC00514 (LINC00514) in OS.

Materials and Methods

The LINC00514 expression was measured using qPCR assays in OS tissues and cell lines. The clinical significance of LINC00514 expression in OS patients was analyzed using chi-square test, Kaplan–Meier assays and multivariate analysis. The possible effects of LINC00514 in tumor cellular progression were determined using a series of functional assays. The mechanisms of LINC00514 action were explored through bioinformatics, luciferase reporter assays and RT-PCR assays. The mechanisms involved the upregulation of LINC00514 expression in OS were determined using luciferase reporter and chromatin immunoprecipitation (ChIP) assays.

Results

We showed that LINC00514 expressions were distinctly upregulated in both OS tissues and cell lines, especially in advanced cases. High levels of LINC0051 were positively correlated with advanced tumor stages, distant metastasis, and reduced survival of patients with OS. Functional experiments indicated that silencing of LINC00514 suppressed the ability of cell growth, colony formation and metastasis, whereas promoted cell apoptosis in vitro. Mechanistic investigation revealed that LINC00514 could directly bind to miR-708 and effectively serve as a ceRNA for miR-708. In addition, LINC00514 was upregulated by the transcription factor SP1.

Conclusion

Our findings revealed SP1-induced upregulation of LINC00514 as an oncogene in OS through competitively binding to miR-708, suggesting that there are potential diagnostic and treatment values of LINC00514 in OS.

LINC00174 is an oncogenic lncRNA of hepatocellular carcinoma and regulates miR-320/S100A10 axis

Hepatocellular carcinoma (HCC) is one of the deadliest cancers. Multiple long non-coding RNAs (lncRNAs) are recently identified as crucial oncogenic factors or tumour suppressors. In this study, we explored the effects of LINC00174 on the progression of HCC. Expression levels of LINC00174 and microRNA-320 (miR-320) in HCC tissue samples were measured using quantitative real-time polymerase chain reaction (qRT-PCR). The association between pathological indices and LINC00174 was also analysed. Human HCC cell lines Hep3B and Huh7 were used as cell models. CCK-8 and bromodeoxyuridine (BrdU) assays were used to assess the effect of LINC00174 on HCC cell line proliferation. Flow cytometry was used to study the effect of LINC00174 on HCC apoptosis. Transwell assay was conducted to detect the effect of LINC00174 on migration and invasion. Furthermore, luciferase reporter assay and RNA immunoprecipitation (RIP) assay were used to confirm the binding relationship between miR-320 and LINC00174. Additionally, western blot was used to detect the regulatory function of LINC00174 on oncogene S100 calcium binding protein A10 (S100A10). We demonstrated that LINC00174 expression in HCC clinical samples was significantly increased and this was correlated with higher T stage. Its overexpression remarkably accelerated proliferation and metastasis of HCC cells while reduced apoptosis. Accordingly, knockdown of it suppressed the malignant phenotypes of HCC cells. Overexpression of LINC00174 significantly reduced the expression of miR-320 by sponging it, in turn enhanced the expression of S100A10. In conclusion, LINC00174 is a sponge of tumour suppressor miR-320, enhances the expression of S100A10 indirectly and functions as an oncogenic lncRNA in HCC. SIGNIFICANCE OF THE STUDY: LINC00174 is a novel lncRNA, whose function is rarely investigated. It is reported that it is oncogenic in colorectal cancer, while its role in HCC remains unclear. Herein, we report that LINC00174 is significantly up-regulated in HCC tissues and promotes the malignant phenotypes. We demonstrate that LINC00174 functions as a sponge for miR-320, increases the expression level of oncogene S100A10 in HCC. This study helps clarify the mechanism of HCC tumorigenesis and progression, and uncover the role of LINC00174 in human disease.

SNHG29 regulates miR-223-3p/CTNND1 axis to promote glioblastoma progression via Wnt/β-catenin signaling pathway

Background

Glioblastoma has been seen as the most common malignancy of brain tumor. Emerging reports has claimed that SNHG29 (LRRC75A-AS1) was involved in several biological processes via modulation of signaling pathway, and served as an malignant facilitatorin osteosarcoma. However, the specific role of SNHG29 in glioblastoma remains unknown.

Methods

RT-qPCR and microarray were operated to measure genes expression. Western blot was performed to examine protein expression. CCK-8 and colony formation assays were used to evaluate cell proliferation. Cell migration was tested by transwell assay. Nuclear-cytoplasmic fractionation was conducted to locate SNHG29. The binding capacity of miR-223-3p to SNHG29 or CTNND1 3′UTR was verified by RIP and luciferase reporter assay.

Results

SNHG29 presented high expression in glioblastoma to boost cell proliferation, migration and EMT process. In addition, miR-223-3p was validated to bind with SNHG29 after prediction and screening. Furthermore, miR-223-3p was proved to be a negative regulator for its target CTNND1. Then, the inhibition on cell proliferation, migration and EMT process resulted from SNHG29 knockdown was recovered by CTNND1 overexpression. At last, the inhibitive impacts on cell proliferation, migration and EMT process of CTNND1 deficiency was abrogated by LiCl.

Conclusions

In conclusion, SNHG29 regulates miR-223-3p/CTNND1 axis to promote glioblastoma progression via Wnt/β-catenin signaling pathway, offering a potential therapeutic point for glioblastoma patients.

LINC00174 down-regulation decreases chemoresistance to temozolomide in human glioma cells by regulating miR-138-5p/SOX9 axis

Temozolomide (TMZ) is one of the most common drugs selected for glioma chemotherapy, but the therapeutic effect of glioma treatment is usually limited due to its resistance. Long non-coding RNA (lncRNA) is gradually found to be a vital regulator in numerous physiological and pathological processes. Lately, it was revealed that LINC00174 could promote CRC cell growth. However, the function and potential regulatory manner of LINC00174 in glioma remain unclear. Our results demonstrated that the expression level of LINC00174 was higher in glioma tissues, and LINC00174 down-regulation could remarkably prevent cell proliferation and promote cell apoptosis in both glioma cells and TMZ-resistant glioma cells. Mechanistic studies revealed that LINC00174 can sponge microRNA-138-5p (miR-138-5p) and down-regulate its expression, thereby up-regulating the protein level of miR-138-5p's target, sex-determining region Y (SRY)-box9 protein (SOX9). Additionally, in vivo experiments revealed that LINC00174 shRNA can serve as a tumor suppressor through down-regulating SOX9 in glioma. In this study, a novel established regulatory way of LINC00174/miR-138-5p/SOX9 axis was systematically studied, which may provide a new manner for glioma therapy.

Role of linc00174/miR-138-5p (miR-150-5p)/FOSL2 Feedback Loop on Regulating the Blood-Tumor Barrier Permeability

The blood-tumor barrier (BTB) limits the transport of chemotherapeutic drugs to brain tumor tissues and impacts the treatment of glioma. Long non-coding RNAs play critical roles in various biological processes of tumors; however, the function of these in BTB permeability is still unclear. In this study, we have identified that long intergenic non-protein coding RNA 174 (linc00174) was upregulated in glioma endothelial cells (GECs) from glioma tissues. Additionally, linc00174 was also upregulated in GECs from the BTB model in vitro. Knock down of linc00174 increased BTB permeability and reduced the expression of the tight junction-related proteins ZO-1, occludin, and claudin-5. Both bioinformatics data and results of luciferase reporter assays demonstrated that linc00174 regulated BTB permeability by binding to miR-138-5p and miR-150-5p. Furthermore, knock down of linc00174 inhibited FOSL2 expression via upregulating miR-138-5p and miR-150-5p. FOSL2 interacted with the promoter regions and upregulated the promoter activity of ZO-1, occludin, claudin-5, and linc00174 in GECs. In conclusion, the present study demonstrated that the linc00174/miR-138-5p (miR-150-5p)/FOSL2 feedback loop played an essential role in regulating BTB permeability.

Long non-coding RNA LINC00174 promotes glycolysis and tumor progression by regulating miR-152-3p/SLC2A1 axis in glioma

BACKGROUND

Long non-coding RNA plays a crucial role in the occurrence and progression of glioma. We aimed to explore the function of LINC00174 in cell proliferation, apoptosis, migration, invasion and glycolysis of glioma cells, and investigate the molecular mechanism involved.

METHODS

LINC00174 expression in glioma tissues and peritumoral brain edema (PTBE) tissues was examined by RT-qPCR and in situ hybridization. The CCK-8, TUNEL, wound healing, transwell, and ELISA assays were performed to identify the effects of LINC00174 knockdown on cell viability, apoptosis, migration, invasion, and glycolysis, respectively. RNA immunoprecipitation, dual-luciferase reporter, RNA pull down, and western blot assays were performed to explore the molecular mechanisms of LINC00174 in glioma cells. A nude mouse xenograft model was used to investigate the role of LINC00174 in xenograft glioma growth.

RESULTS

LINC00174 was overexpressed in glioma tissues and cell lines. LINC00174 knockdown inhibited cell proliferation, migration, invasion and glycolysis of glioma cells, and LINC00174 exerted a tumorigenesis role. LINC00174 could interact with miR-152-3p/SLC2A1 axes. The miR-152-3p inhibitor or the SLC2A1 overexpression could rescue the anti-tumor effect of LINC00174 knockdown on glioma cells. Moreover, downregulation of LINC00174 also inhibited tumor volume and delayed the tumor growth in vivo.

CONCLUSION

LINC00174 accelerated carcinogenesis of glioma via sponging miR-1523-3p and increasing the SLC2A1 expression, which could be considered as a molecular target for glioma diagnosis and therapy.

SP1-mediated upregulation of lncRNA ILF3-AS1 functions a ceRNA for miR-212 to contribute to osteosarcoma progression via modulation of SOX5

Long noncoding RNA ILF3-AS1 (ILF3-AS1) has been reported to be abnormally expressed in several tumors. However, its expression pattern and function in osteosarcoma have not been investigated. In this study, we showed that ILF3-AS1 expression was significantly up-regulated in both osteosarcoma tissues and cell lines. We first reported that ILF3-AS1 upregulation was induced by nuclear transcription factor SP1. Clinical assays revealed that higher expression of ILF3-AS1 was associated with advanced clinical stage, distant metastasis and shorter overall survival. in multivariate analysis, ILF3-AS1 expression level was found to be an independent prognostic factor for osteosarcoma patients. Functional investigations showed that knockdown of ILF3-AS1 suppressed the proliferation, migration and invasion of osteosarcoma cells, and promoted apoptosis. Bioinformatic software predicted that miR-212 both targeted the 3'-UTR of ILF3-AS1 and SOX5, which was confirmed using luciferase reporter assay, RT-PCR and Western blot. Taken together, ILF3-AS1 displayed its tumor-promotive roles in the progression of osteosarcoma through miR-212/SOX5 axis. Our findings help to elucidate the tumorigenesis of osteosarcoma, and future study will provide a novel therapeutic target for osteosarcoma.

Bortezomib-inducible long non-coding RNA myocardial infarction associated transcript is an oncogene in multiple myeloma that suppresses miR-29b

Clinical outcomes of patients with multiple myeloma (MM) have almost doubled the overall survival over the last decade owing to the use of proteasome inhibitor such as bortezomib (BTZ). However, some patients with MM develop primary resistance to BTZ, whereas others develop resistance after treatment. In this study, we investigated relationships between BTZ resistance and dysfunction of long non-coding RNAs (lncRNAs) in patients with MM. Bone marrow samples were collected from patients with MM and healthy donors for lncRNA microarray and survival analyses. To investigate functions and underlying mechanisms of lncRNA-mediated BTZ resistance in MM, we performed CCK-8 assays, flow cytometry analyses, dual luciferase report gene assays, and RNA pulldown assays with samples from nude mice carrying tumor xenografts and in clinical samples. Differentially expressed lncRNA myocardial infarction associated transcripts (MIAT) were highly expressed in patients with MM compared with healthy controls, and were predictive of poor survival outcomes. Moreover, MIAT expression was significantly increased in BTZ-resistant patients with MM compared with newly diagnosed patients with MM, and was identified as a BTZ-inducible lncRNA. Specifically, BTZ upregulated MIAT expression through increased stat1 phosphorylation. Silencing of MIAT inhibited MM cell growth and sensitized MM cells to BTZ by negatively regulating miR-29b. Our data demonstrated the utility of MIAT as a tool for overcoming BTZ resistance in patients with MM.

LncRNA HAND2-AS1 sponging miR-1275 suppresses colorectal cancer progression by upregulating KLF14

Long noncoding RNAs (lncRNAs) represent a novel type of noncoding RNAs of over 200 nucleotides, characterized by no or limited protein-coding potential. Although the function of lncRNAs attracts increasing attention recently, the relationship between lncRNA and colorectal cancer (CRC) remains further investigation. In our study, we found that lncRNA HAND2-AS1 was markedly downregulated in CRC tissues. And its expression level was negatively correlated with metastasis and advanced stage in CRC patients. Furthermore, we showed that HAND2-AS1 low expression predicted poor prognosis. Functionally, we found that overexpression of HAND2-AS1 obviously attenuated the proliferation and invasion of CRC cells. Ectopic expression of HAND2-AS1 also inhibited tumor propagation in vivo. In mechanism, HAND2-AS1 served as a sponge of miR-1275 which targeted KLF14. Through facilitating KLF14 expression, HAND2-AS1 suppressed CRC progression. In conclusion, our study demonstrated that HAND2-AS1 exerts a suppressive role in CRC by sponging miR-1275 and modulating KLF14 expression.