Long noncoding RNA LINC00473 drives the progression of pancreatic cancer via upregulating programmed death-ligand 1 by sponging microRNA-195-5p

Pancreatic cancer (PC) is a great health burden to patients owing to its poor overall survival rate. Long noncoding RNAs (lncRNAs) interact with microRNAs (miRs) to participate in tumorigenesis. Therefore, we aim to uncover the role and related mechanism of LINC00473 in PC through the modulation of miR-195-5p and programmed death-ligand 1 (PD-L1). Increased LINC00473 and PD-L1 but declined miR-195-5p were determined in PC tissues and cell lines, and it was found that LINC00473 mainly situated in the cytoplasm. Also, miR-195-5p was verified to bind with both LINC00473 and PD-L1. Next, with the aim to examine the ability of LINC00473, miR-195-5p, and PD-L1 on the PC progression, the expression of LINC00473, miR-195-5p and PD-L1 were altered with mimics, inhibitors, overexpression vectors or siRNAs in PC cells and cocultured CD8⁺ T cells. It was demonstrated that LINC00473 sponged miR-195-5p to upregulate PD-L1 expression. More important, the obtained results revealed that LINC00473 silencing or miR-195-5p upregulation elevated the expression of Bcl-2 associated X protein (Bax), interferon (IFN)-γ, and interleukin (IL)-4 but reduced the expression of B-cell lymphoma-2 (Bcl-2), matrix metalloproteinase (MMP)-2, MMP-9, and IL-10, thus inducing the enhancement of the apoptosis as along with the inhibition of proliferation, invasion, and migration of the PC cells. LINC00473 silencing or miR-195-5p elevation activated the CD8⁺ T cells. Taken together, LINC00473 silencing blocked the PC progression through enhancing miR-195-5p-targeted downregulation of PD-L1. This finding offers new therapeutic options for treating this devastating disease.     

LINC00473/miR-374a-5p regulates esophageal squamous cell carcinoma via targeting SPIN1 to weaken the effect of radiotherapy

Esophageal squamous cell carcinoma (ESCC) is the most prevalent type in esophageal cancers. Despite accumulating achievements in treatments of ESCC, patients still suffer from recurrence because of the treatment failures, one of the reasons for which is radioresistance. Therefore, it is a necessity to explore the molecular mechanism underlying ESCC radioresistance. Long intergenic noncoding RNA 473 (LINC00473) has been reported to be aberrantly expressed in several human malignancies. However, its biological function in radiosensitivity of ESCC remains to be fully understood. This study explored the role of LINC00473 in radiosensitivity of ESCC cells and whether LINC00473 acted as a competing endogenous RNA to realize its modulation on radioresistance. We found that LINC00473 was markedly upregulated in ESCC tissues and cell lines, and its expression was remarkably related to cellular response to irradiation. In addition, knockdown of LINC00473 could sensitize ESCC cells to radiation in vitro. As for the underlying mechanism, we uncovered that there was a mutual inhibition between LINC00473 and miR-374a-5p. Spindlin1 (SPIN1) was verified as a downstream target of miR-374a-5p, and LINC00473 upregulated SPIN1 expression through negatively modulating miR-374a-5p expression. Furthermore, we revealed that SPIN1 could aggravate the radioresistance of ESCC cells. Finally, overexpression of SPIN1 reversed the LINC00473 silencing-enhanced radiosensitivity in ESCC cells. To sum up, we demonstrated that LINC00473 facilitated radioresistance by regulating the miR-374a-5p/SPIN1 axis in ESCC.     

LINC00152 promotes cell cycle progression in hepatocellular carcinoma via miR-193a/b-3p/CCND1 axis

Long intergenic non-coding RNA 00152 (LINC00152) is aberrantly expressed in various human malignancies and plays an important role in the pathogenesis. Here, we found that LINC00152 is upregulated in hepatocellular carcinoma (HCC) tissues as compared to adjacent non-neoplastic tissues; gain-and-loss-of-function analyses in vitro showed that LINC00152 facilitates HCC cell cycle progression through regulating the expression of CCND1. LINC00152 knockdown inhibits tumorigenesis in vivo. MS2-RIP analysis indicated that LINC00152 binds directly to miR-193a/b-3p, as confirmed by luciferase reporter assays. Furthermore, ectopic expression of LINC00152 partially halted the decrease in CCND1 expression and cell proliferation capacity induced by miR-193a/b-3p overexpression. Thus, LINC00152 acts as a competing endogenous RNA (ceRNA) by sponging miR-193a/b-3p to modulate its target gene, CCND1. Our findings establish a ceRNA mechanism regulating cell proliferation in HCC via the LINC00152/miR-193a/b-3p/CCND1 signalling axis, and identify LINC00152 as a potential therapeutic target for HCC.     

Long intergenic noncoding RNA 00641 inhibits breast cancer cell proliferation,migration, and invasion by sponging miR-194-5p

Long noncoding RNAs have an essential role in the tumorigenesis of breast cancer (BC). Nonetheless, the consequences of long intergenic noncoding RNA 00641 (LINC00641) in BC remain unidentified. This study shows that LINC00641 expression level was decreased in BC tissues. LINC00641 expression level was negatively related to tumor size, lymph-node metastasis, as well as clinical stage. LINC00641 overexpression inhibited cell proliferation, migration, and invasion but stimulated apoptosis in BC cells. LINC00641 overexpression also remarkably reduced BC growth and metastasis in vivo. LINC00641 acts as a competitive endogenous RNA to sponge miR-194-5p. miR-194-5p level was higher in BC tissues and cells compared with normal-adjacent tissues and normal breast epithelial cell. miR-194-5p expression was negatively correlated with LINC00641 expression in BC tissues. miR-194-5p overexpression reversed the effects of LINC00641 on cell proliferation, cycle, apoptosis, migration, as well as invasion. In conclusion, LINC00641 inhibits BC cell proliferation, migration, as well as invasion by sponging miR-194-5p.     

Long non-coding RNA LINC01347 suppresses trophoblast cell migration,invasion and EMT by regulating miR-101–3p/PTEN/AKT axis

Recurrent miscarriage (RM) is one of the common complications of pregnancy, which is closely related to gene mutation. The profiling of non-coding RNAs showed that the expression level of long non-coding RNA LINC01347 (LINC01347) in the serum of patients with recurrent abortion was significantly increased, which could serve as a potential marker for early diagnosis. However, the biological functions of LINC01347 in the miscarriage remain to be elucidated. In this study, LINC01347 expression levels in HTR-8/SVneo cells and placenta samples were measured by RT-qPCR. The migration ability of HTR-8/SVneo cells was detected by wound-healing assay. Western blotting (WB) assay was conducted to measure E-cadherin, Vimentin, N-cadherin, PTEN, phospho-AKT(S473), phospho-AKT(T308) and AKT levels. Dual luciferase reporter assay and RNA pull-down analysis were performed to validate the molecular interactions. The results showed an upregulation of LINC01347 in the placenta samples of RM patients and HTR-8/SVneo cells. LINC01347 overexpression impaired the invasion and migration of trophoblast cells, while LINC01347 silencing promoted cell migration and invasion. LINC01347 level was also negatively correlated with the changes of epithelial-mesenchymal transition (EMT) markers in trophoblasts. We further demonstrated that miR-101–3p/PTEN/AKT axis played an important role in mediating the biological roles of LINC01347 in the invasion and migration of trophoblasts. In conclusion, our results revealed that LINC01347 suppresses the migratory ability and regulates the EMT processes in trophoblasts by regulating miR-101–3p/PTEN/AKT axis, suggesting that targeting LINC01347 may serve as a strategy to ameliorate RM.     

Long noncoding RNA LINC00941 promotes pancreatic cancer progression by competitively binding miR-335-5p to regulate ROCK1-mediated LIMK1/Cofilin-1 signaling

An accumulation of evidence indicates that long noncoding RNAs are involved in the tumorigenesis and progression of pancreatic cancer (PC). In this study, we investigated the functions and molecular mechanism of action of LINC00941 in PC. Quantitative PCR was used to examine the expression of LINC00941 and miR-335-5p in PC tissues and cell lines, and to investigate the correlation between LINC00941 expression and clinicopathological features. Plasmid vectors or lentiviruses were used to manipulate the expression of LINC00941, miR-335-5p, and ROCK1 in PC cell lines. Gain or loss-of-function assays and mechanistic assays were employed to verify the roles of LINC00941, miR-335-5p, and ROCK1 in PC cell growth and metastasis, both in vivo and in vitro. LINC00941 and ROCK1 were found to be highly expressed in PC, while miR-335-5p exhibited low expression. High LINC00941 expression was strongly associated with larger tumor size, lymph node metastasis, and poor prognosis. Functional experiments revealed that LINC00941 silencing significantly suppressed PC cell growth, metastasis and epithelial–mesenchymal transition. LINC00941 functioned as a molecular sponge for miR-335-5p, and a competitive endogenous RNA (ceRNA) for ROCK1, promoting ROCK1 upregulation, and LIMK1/Cofilin-1 pathway activation. Our observations lead us to conclude that LINC00941 functions as an oncogene in PC progression, behaving as a ceRNA for miR-335-5p binding. LINC00941 may therefore have potential utility as a diagnostic and treatment target in this disease.Subject terms: Pancreatic cancer, Long non-coding RNAs     

Retracted: Long noncoding LINC01551 promotes hepatocellular carcinoma cell proliferation,migration, and invasion by acting as a competing endogenous RNA of microRNA-122-5p to regulate ADAM10 expression

Hepatocellular carcinoma (HCC) is a severe disease with high mortality in the world. It has been shown that long noncoding RNA (lncRNA) might play a role in HCC. The aim of the present study was to identify the role of long intergenic noncoding RNA 01551 (LINC01551) in the HCC development and explore the underlying mechanism of LINC01551/miR-122-5p/ADAM10 axis. The differentially expressed lncRNAs associated with HCC were screened out by a microarray analysis. The expression of LINC01551, miR-122-5p, and ADAM10 was determined in HCC tissues and cells. The potential miRNA (miR-122-5p) regulated by LINC01551 was explored, and the target relationship between miR-122-5p and ADAM10 was confirmed. To evaluate the effect of LINC01551 and miR-122-5p on proliferation, migration, invasion, and apoptosis of HCC, different plasmids were delivered into MHCC97-H cells. High expression of LINC01551 and ADAM10 yet low-expression of miR-122-5p were revealed in HCC tissues and cells. Overexpression of miR-122-5p could downregulate ADAM10. Biological prediction websites and fluorescence in situ hybridization assay verified that LINC01551 was mainly expressed in the cytoplasm. Silencing LINC01551 reduced HCC cell viability, proliferation, migration, invasion, and cell cycle entry yet induce cell apoptosis. Upregulation of LINC01551 increased its ability of competitively binding to miR-122-5p, thus reducing miR-122-5p and upregulating ADAM10 expression, as well as promoting the proliferative, migrative, and invasive ability. Taken together the results, it is highly possible that LINC01551 functions as an competing endogenous RNA (ceRNA) to regulate the miRNA target ADAM10 by sponging miR-122-5p and therefore promotes the development of HCC, highlighting a promising competitive new target for the HCC treatment.     

LINC00473 antagonizes the tumour suppressor miR‐195 to mediate the pathogenesis of Wilms tumour via IKKα

Objectives

Although dramatic improvements of overall survival has achieved in patients with favourable histology Wilms tumour, disease recurrence is still the main cause of cancer‐related death in childhood. Long non‐coding RNAs (lncRNAs) as oncogenes or tumour suppressors are dysregulated during carcinogenesis. However, the role of lncRNAs in the pathogenesis of Wilms tumour is unknown. Here, an lncRNA LINC00473 signature that functioned as oncogene was identified in Wilms tumour.

Methods

Wilms tumour (n = 15) and relative normal tissues were collected. The LINC00473 expression and function in Wilms tumour was determined. The LncRNA‐miRNA network of LINC00473 was analysed in vitro and vivo.

Results

We uncovered that the expression of LINC00473 was elevated in tumour tissues than that in relative normal tissues. Higher LINC00473 levels correlated to higher stage and unfavourable histology Wilms tumour. Mechanistically, knockdown of LINC00473 inhibited cell vitality and induced Bcl‐2‐dependent apoptosis and G1/S arrest via CDK2 and cyclin D1. Moreover, LINC00473 harboured binding sites for miR‐195 and limited miR‐195 availability in a dose‐dependent manner. Forced expression of miR‐195 impaired tumour survival and metastasis, which, however, could be restored by LINC00473. Furthermore, IKKα was the downstream of LINC00473/miR‐195 signals and could be directly targeted by miR‐195 to participate LINC00473‐induced tumour progression. Loss‐of‐function of LINC00473 in vivo effectively promoted the regression of Wilms tumour via miR‐195/IKKα‐mediated growth inhibition.

Conclusion

LINC00473 as an oncogene is up‐regulated to participate into the molecular pathogenesis of Wilms tumour via miR‐195/IKKα.     

LINC00184 plays an oncogenic role in non-small cell lung cancer via regulation of the miR-524-5p/HMGB2 axis

Non-small cell lung cancer (NSCLC) is the most common type of lung cancer. We aimed to investigate the role of LINC00184 in NSCLC. Migration, proliferation and invasion of NSCLC cells were analysed using the wound healing assay, cell counting kit-8 assay and transwell assay, respectively. Apoptosis and cell cycle were assessed using flow cytometry. Online bioinformatics tools were utilized to predict downstream microRNAs (miRNA) or genes related to LINC00184 expression. The RNA pull-down experiment and luciferase reporter assay were performed to verify the predictions thereof. LINC00184, miR-524-5p, and high mobility group 2 protein (HMGB2) expression levels in NSCLC tissues and cell lines were detected using quantitative real-time polymerase chain reaction. An NSCLC mouse model was constructed for in vivo experiments. LINC00184 overexpression was observed in NSCLC tissues and cell lines and was found to be correlated with poor prognosis. LINC00184 knockdown inhibited cell proliferation, migration and invasion, induced cell cycle arrest and accelerated apoptosis in NSCLC cell lines. LINC00184 suppressed tumour growth and proliferation in NSCLC mouse models and directly targeted the miR-524-5p/HMGB2 axis. Moreover, the expression levels of LINC00184 and HMGB2 were negatively correlated with miR-524-5p expression, whereas LINC00184 expression was positively correlated with HMGB2 expression. LINC00184 affected the cell cycle, proliferation, apoptosis, migration and invasion in NSCLC via regulation of the miR-524-5p/HMGB2 axis.     

LINC00839 Promotes Neuroblastoma Progression by Sponging miR-454-3p to Up-Regulate NEUROD1

Neuroblastoma (NB) is the most common extracranial solid malignancy in children. Increasing long non-coding RNAs (lncRNAs) are reported to be associated with NB tumorigenesis and aggressiveness. Here, we attempted to investigate the biological functions of LINC00839 in NB progression as well as its possible pathogenic mechanisms. Public microarray datasets were applied to unearth the abnormally expressed lncRNAs in NB. RT-qPCR analysis was used to measure the expression of LINC00839, miR-454-3p, and neuronal differentiation 1 (NEUROD1) mRNA. The protein level was determined by a western blot assay. CCK-8, plate clone formation, EdU, wound-healing scratch, and transwell assays were employed to evaluate cell proliferation, migration, and invasion. Xenografts were developed in nude mice to determine the effects of LINC00839 on NB tumor growth. Dual-luciferase reporter and RNA immunoprecipitation (RIP) experiments were performed to identify the interaction between miR-454-3p and LINC00839 or NEUROD1. According to GSE datasets (GSE16237 and GSE16476), LINC00839 was found as a potential driver of NB progression. LINC00839 expression was higher in NB tumor tissues and cells. Also, LINC00839 expression was positively correlated with MYCN amplification, advanced INSS stages, and worse prognosis. Silencing of LINC00839 suppressed cell proliferation, migration, invasion, and epithelial-mesenchymal transition (EMT) in vitro. Mechanistically, LINC00839 could act as a sponge of miR-454-3p to facilitate the expression of its target NEUROD1. Moreover, miR-454-3p was demonstrated to exert an anti-cancer activity in NB. More importantly, the tumor-suppressive properties mediated by LINC00839 knockdown were significantly counteracted by the inhibition of miR-454-3p or overexpression of NEUROD1. Our study demonstrates that LINC00839 exerts an oncogenic role in NB through sponging miR-454-3p to up-regulate NEUROD1 expression, deepening our comprehension of lncRNA involved in NB and providing access to the possibility of LINC00839 as a therapeutic target for NB.

     

Long non-coding RNA 657 suppresses hepatocellular carcinoma cell growth by acting as a molecular sponge of miR-106a-5p to regulate PTEN expression

Previous study has identified the aberrant expression of LINC00657, a long non-coding RNA (lncRNA), in human breast cancer. However, the expression pattern, biological function and underlying mechanism of LINC00657 in human hepatocellular carcinoma (HCC) remain obscure. The expression levels of LINC00657 in HCC tissues and cell lines were determined by quantitative real-time PCR. CCK-8 assay, cell colony formation assay, cell cycle analysis, Transwell assay were performed to determine whether LINC00657 could affect HCC progression. Luciferase reporter assay was used to assess the target of LINC00657. Expressions of the relevant proteins were analyzed by Western blot. Herein, we found that LINC00657 was downregulated in HCC tissue specimens as well as in malignant HCC cell lines. LINC00657 overexpression inhibited the proliferation, migration and invasion of HCC cells, while LINC00657 depletion promoted both cell viability and cell invasion in vitro. We also found that LINC00657 could inhibit tumor growth in vivo. Further experiments demonstrated that down-regulated LINC00657 increased the expression of miR-106a-5p. miR-106a-5p decreased the abundances of PTEN protein, while had no impact on PTEN mRNA. Moreover, we identified that both LINC00657 and PTEN mRNA were targets of miR-106a-5p by using dual-luciferase reporter assay. Our results provide the new evidence supporting the tumor-suppressive role of LINC00657 in HCC, suggesting that LINC00657 might play a role in HCC and can be a novel therapeutic target for treating HCC.     

Retracted: LINC00707 contributes to hepatocellular carcinoma progression via sponging miR-206 to increase CDK14

Recently, increasing numbers of long noncoding RNAs (lncRNAs) have been found to be aberrantly expressed in various cancers. However, the roles of lncRNAs in hepatocellular carcinoma (HCC) progression is largely unknown. In our current study, we identified that long intergenic nonprotein-coding RNA 707 (LINC00707) was remarkably elevated in HCC cells, indicating that LINC00707 was involved in HCC development. Subsequently, LINC00707 was significantly decreased in HepG2 and Huh7 cells. The in vitro functional assays demonstrated that knockdown of LINC00707 significantly reduced HCC cell proliferation, induced cell apoptosis, and blocked the cell cycle progression. In addition, HCC cell migration and invasion was also greatly inhibited by downregulation of LINC00707. Increasing evidence has indicated that lncRNAs can act as molecular sponges of microRNAs. Currently, we observed that microRNA-206 (miR-206) was dramatically inhibited in HCC cells and LINC00707 can modulate HCC development through sponging miR-206. The binding correlation between LINC00707 and miR-206 was confirmed by dual-luciferase reporter assay, RNA pull down and RNA immunoprecipitation assay in our study. Moreover, cyclin-dependent kinase 14 (CDK14) was predicted as a target of miR-206 and we found that miR-206 suppressed CDK14 levels in HCC cells. Finally, in vivo assays were used and it was proved that silence of LINC00707 can restrain HCC development through modulating miR-206 to upregulate CDK14. In conclusion, it was implied that LINC00707 can lead to HCC progression through sponging miR-206 and modulating CDK14.     

RNA methylation-mediated LINC01559 suppresses colorectal cancer progression by regulating the miR-106b-5p/PTEN axis

Long noncoding RNAs (lncRNAs) regulate multiple biological effects in cancers. Recently, RNA methylation has been found to modify not only coding RNAs but also some noncoding RNAs. How RNA methylation affects lncRNAs to affect colorectal cancer (CRC) progression remains elusive. The expression of LINC01559 was explored through RNA sequencing, quantitative real-time PCR (qRT-PCR) and in situ hybridization (ISH). The preliminary exploration of its function was performed using Western blotting (WB) and immunohistochemistry (IHC). Functional experiments in vitro and in vivo were conducted to explore the biological functions of LINC01559 in CRC. The LINC01559/miR-106-5p/PTEN axis was verified through fluorescence in situ hybridization (FISH), luciferase assays, and rescue experiments. RIP-sequencing, m6A RNA immunoprecipitation (MeRIP) assays and bioinformatic analysis were conducted to determine the upstream mechanism of LINC01559. The results showed that LINC01559 was downregulated in CRC compared with normal controls. Lower expression of LINC01559 in CRC patients predicted a poor prognosis. In addition, PTEN was found to be positively correlated with LINC01559, and miR-106b-5p could be the link between LINC01559 and PTEN. Then, silencing LINC01559 restored the malignant phenotype of CRC cells, while cotransfection of miR-106b-5p inhibitor neutralized this effect. Mechanistically, we found abundant m6A modification sites on LINC01559. Then, we uncovered these sites as potential targets of METTL3 through experiments in vivo. The results revealed a negative functional regulation of the LINC01559/miR-106b-5p/PTEN axis in CRC progression and explored a new mechanism of METTL3-mediated m6A modification on LINC01559. These results elucidate a novel potential therapeutic target for CRC treatment.