LncSHRG promotes hepatocellular carcinoma progression by activating HES6

HES6 Mediates Oxidative Phosphorylation Pathway to Promote Immune Infiltration of CD8 + T Cells in Lung Adenocarcinoma

Tumor immunotherapy has recently gained popularity as a cancer treatment strategy. The molecular mechanism controlling immune infiltration in lung adenocarcinoma (LUAD) cells, however, is not well characterized. Investigating the immune infiltration modulation mechanism in LUAD is crucial. LUAD patient samples were collected, and HES6 expression and immune infiltration level of CD8 + T cells in patient tissues were analyzed. Bioinformatics was utilized to identify binding relationship between E2F1 and HES6, and enrichment pathway of HES6. The binding of E2F1 to HES6 was verified using dual-luciferase and ChIP experiments. HES6 and E2F1 expression in LUAD cells was detected. LUAD cells were co-cultured with CD8 + T cells, and the CD8 + T cell killing level, IFN-γ secretion, and CD8 + T-cell chemotaxis level were measured. Expression of key genes involved in oxidative phosphorylation was detected, and the oxygen consumption rate of LUAD cells was assessed. A mouse model was constructed to assay Ki67 expression and apoptosis in tumor tissue. High expression of HES6 promoted CD8 + T-cell infiltration and enhanced T-cell killing ability through oxidative phosphorylation. Further bioinformatics analysis, molecular experiments, and cell experiments verified that E2F1 negatively regulated HES6 by oxidative phosphorylation, which suppressed CD8 + T-cell immune infiltration. In addition, in vivo assays illustrated that silencing HES6 repressed tumor cell immune evasion. E2F1 inhibited HES6 transcription, thereby mediating oxidative phosphorylation to suppress immune infiltration of CD8 + T cells in LUAD. The biological functions and signaling pathways of these genes were analyzed, which may help to understand the possible mechanisms regulating immune infiltration in LUAD.

A comprehensive review of the role of lncRNAs in gastric cancer (GC) pathogenesis, immune regulation, and their clinical applications

Gastric cancer (GC) is the fifth most common malignant tumor and the third leading cause of cancer-related deaths worldwide. Although numerous studies have been conducted on advanced GC, the molecular mechanisms behind it remain obscure. Long non-coding RNAs (lncRNAs) are a family of RNA transcripts capable of regulating target genes at transcriptional, post-transcriptional, and translational stages. They do this by modifying mRNAs, miRNAs, and proteins. These RNAs are critical regulators of many biological processes, including gene epigenetics, transcription, and post-transcriptional levels. This article highlights recent results on lncRNAs involved in drug resistance, proliferation, migration, angiogenesis, apoptosis, autophagy, and immune response in GC. The potential clinical implications of lncRNAs as biomarkers and therapeutic targets in GC are also discussed.

The prognostic value of lncRNA AGAP2-AS1 in cancer patients: A meta-analysis

BACKGROUND

ArfGAP with GTPase domain, Ankyrin repeat and PH domain 2 Antisense 1 (AGAP2-AS1) is a promising long noncoding RNA that may possess prognostic value for different types of tumors. The objective of this meta-analysis is to evaluate the prognostic value of long noncoding RNA AGAP2-AS1 in cancer patients.

METHODS

A systematic literature search of the PubMed, Cochrane Library, EMBASE, Medline, Web of Science, CNKI, Weipu, and Wanfang electronic databases were carried out in this meta-analysis. Synthetic hazard ratios (HRs) or odd ratios (ORs) with 95% confidence intervals (CIs) were obtained to determine the prognostic and clinicopathological significance of AGAP2-AS1 expression in tumors.

RESULTS

The final meta-analysis included 10 studies that contained 948 patients. The pooled results provided evidence that AGAP2-AS1 overexpression predicted reduced overall survival (OS) (HR = 1.77, 95% CI: 1.49-2.09, P < .00001), disease-free survival (HR = 1.84, 95% CI: 1.40-2.41, P < .0001), and progression-free survival (HR = 1.84, 95% CI: 1.01-3.33, P = .04) and for various cancers. Additionally, the AGAP2-AS1 overexpression was concerned with lymph node metastasis (positive vs negative, OR = 2.95, 95% CI: 1.96-4.45, P < .00001), advanced tumor node metastasis stage (III/IV vs I/II, OR = 3.73, 95% CI: 2.71-5.13, P < .00001), and tumor size (larger vs smaller, OR = 2.28, 95% CI: 1.24-4.18, P = .008). Besides, data from gene expression profiling interactive analysis dataset verified the results in our meta-analysis. The results showed that the expression level of AGAP2-AS1 was higher in most tumor tissues than in the corresponding normal tissues and was linked to poor OS and disease-free survival.

CONCLUSIONS

Our results indicated that AGAP2-AS1 overexpression was closely correlated with shorter OS in multiple cancer types, suggesting that AGAP2-AS1 might function as a promising predictor for clinical outcomes in cancer.

LINC00665 promotes cell proliferation, invasion, and metastasis by activating the TGF-β pathway in gastric cancer

BACKGROUND AND AIMS

Accumulating studies have demonstrated that long noncoding RNA plays a vital role in cancer progression. A previous study reported that LINC00665 was overexpressed and acted as a key tumor promoter in lung cancer, but the role of LINC00665 in gastric cancer (GC) remained uncharacterized. Thus, this study aimed to explore the mechanism of LINC00665 in GC.

METHODS

LINC00665 expression was explored using the Cancer Genome Atlas (TCGA), and a meta-analysis was conducted to assess the expression and prognostic value of LINC00665 in GC from Gene Expression Omnibus databases and the TCGA dataset. Real-time polymerase chain reaction (RT-PCR) was then conducted to verify the LINC00665 expression in GC tissues and cell lines. The effects of LINC00665 on cell proliferation, invasion, metastasis, and cell cycle in GC were evaluated using the CCK-8, wound healing, Transwell, and flow cytometry assays. In vitro validation was also performed.

RESULTS

LINC00665 overexpression was found in GC, and LINC00665 upregulation was significantly related to poor overall survival and disease-free survival. LINC00665 expression was associated with tumor depth, lymph node metastasis, and TNM stage. Univariate and multivariate analyses proved that LINC00665 could be an independent prognostic biomarker in GC. LINC00665 knockdown subsequently inhibited cell proliferation, invasion, and metastasis in GC cell lines; promoted cell apoptosis; and arrested GC cell lines in the G0/G1 phase. Western blot analysis indicated that LINC00665 silencing inhibited epithelial-mesenchymal transition and decreased the expression levels of TGF-β1, Smad2, and α-SMA.

CONCLUSION

LINC00665 can be a potential diagnostic and prognostic biomarker for GC patients, and LINC00665 promotes GC cell proliferation, invasion, and metastasis by activating the TGF-β signal pathway.

Immune marker signature helps to predict survival in uveal melanoma

The detailed molecular function of tumor microenvironment (TEM) in uveal melanoma (UVM) remains unclear. This study generated the immune index and the stromal index scores by ESTIMATE algorithm based on RNA-sequencing data with 80 UVM patients. There was no correlation between the immune stromal index and clinical parameters. The differentially expressed genes related to the immune stromal index were calculated and were described by functional annotations and protein-protein interaction network diagrams. After univariate and multivariate Cox regression analyses, there were four genes (HLA-J, MMP12, HES6, and ADAMDEC1) with significant prognostic significance. The prognostic model was constructed using these four characteristic genes, and the KM curve and tROC curve were described to show that the model had a better ability to predict survival outcomes and prognosis. The verification results in GSE62075 showed that HLA-J and HES6 were expressed differently in the cancer group than in the non-cancer group. This study indicates that the risk signature based on the immune index can be used as an indicator to evaluate the prognosis of patients with UVM.

LncRNA SNHG15 Contributes to Immuno-Escape of Gastric Cancer Through Targeting miR141/PD-L1

Introduction

Long non-coding RNAs (lncRNAs) have been demonstrated to participate in many biological processes and severs as important regulators during the progression of gastric cancer.

Methods

Here, we introduced human lncRNA SNHG15 which was highly expressed in gastric cancer and cells. Interestingly, the expression of SNHG15 was correlated with programmed cell death ligand 1 (PD-L1), which promotes the resistance of gastric cancer cells to immune responses. Meanwhile, SNHG15 downregulation suppressed the expression of PD-L1 and resistance of immune responses.

Results

Further, our results suggested that SNHG15 acted as a competing endogenous RNA (CeRNA) to sponge miR-141, which was downregulated in gastric cancers and negatively correlated to PD-L1.

Conclusion

Our results suggested that SNHG15 improved the expression of PD-L1 by inhibiting miR-141, which in turn promoted the resistance of stomach cancer cells to the immune responses.

Long noncoding RNA MAFG-AS1 promotes proliferation, migration and invasion of hepatocellular carcinoma cells through downregulation of miR-6852

Long noncoding RNAs (lncRNAs) have been shown to participate in the development and progression of a number of different types of cancer, including hepatocellular carcinoma (HCC). A recent report has indicated that lncRNA MAFG-antisense 1 (AS1) promotes colorectal cancer. However, the role of MAFG-AS1 in other types of cancer remains unclear. The aim of the present study was to examine the effect of lncRNA MAFG-AS1 in HCC. Based on The Cancer Genome Atlas database and reverse transcription-quantitative PCR results, it was determined that lncRNA MAFG-AS1 expression was increased in HCC tissues and cell lines. Following knockdown of lncRNA MAFG-AS1, a Cell Counting Kit-8 assay and Transwell assay demonstrated that the proliferation, migration and invasion of HCC cell lines were significantly inhibited. It was additionally demonstrated that there was a negative regulatory association between lncRNA MAFG-AS1 and miR-6852. Inhibition of miR-6852 increased proliferation, migration and invasion of HCC cell lines. LncRNA MAFG-AS1 promoted HCC development by dampening miR-6852 function and may thus be a novel target for treating patients with HCC.

Long non-coding RNA IQCJ-SCHIP1 antisense RNA 1 is downregulated in colorectal cancer and inhibits cell proliferation

Background

IQCJ-SCHIP1 antisense RNA 1 (IQCJ-SCHIP1-AS1) was a functional novel long non-coding RNA (lncRNA) revealed by our previous expression profile. In this study, we aim to investigate its clinical relevance and biological significance in colorectal cancer (CRC).

Methods

We measured the expression levels of IQCJ-SCHIP1-AS1 in 86 paired CRC tissues using quantitative RT-PCR assay, and then analyzed its association with patient prognoses. Moreover, gain-of-function and loss-of-function studies were performed to examine the biological functions of IQCJ-SCHIP1-AS1. Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG) and gene set enrichment analysis (GSEA) were used to elucidate potential mechanisms of IQCJ-SCHIP1-AS1 in CRC.

Results

More than 2-fold decreased expression of IQCJ-SCHIP1-AS1 was found in half of CRC tissues (53.5%, 46/86). IQCJ-SCHIP1-AS1 down-regulation was correlated with poor differentiation (P=0.025), advanced depth of tumor (P=0.022), lymphatic invasion (P=0.010), advanced tumor stage (P=0.006), and poor prognosis (P=0.0027) in CRC patients. The Cox proportional hazards model demonstrated that IQCJ-SCHIP1-AS1 expression was an independent prognostic factor for CRC (HR =0.247, 95% CI: 0.081-0.752, P=0.014). Moreover, knockdown of IQCJ-SCHIP1-AS1 promoted CRC cell proliferation through increasing cell cycle progression and impairing cell apoptosis. Additionally, bioinformatics analysis showed that differential expression genes in IQCJ-SCHIP1-AS1-depleted CRC cells were enriched in the pathways of cell cycle, DNA replication, and p53.

Conclusions

Our results demonstrate that IQCJ-SCHIP1-AS1 has an indicative tumor suppressor role and appears to be a potential prognostic factor in CRC for the first time.

Long Noncoding RNA HOTTIP Promotes Nasopharyngeal Cancer Cell Proliferation, Migration, and Invasion by Inhibiting miR-4301

BACKGROUND The long noncoding RNA (lncRNA) HOTTIP is involved in gastric cancer tumorigenesis, papillary thyroid carcinoma, colorectal cancer, lung adenocarcinoma, and hepatocellular carcinoma, but it is unclear how HOTTIP exerts roles in nasopharyngeal carcinoma (NPC). The present study investigated HOTTIP function during NPC development. MATERIAL AND METHODS HOTTIP levels in cancer specimens and cell lines were analyzed using qRT-PCR. HOTTIP function in NPC was determined by Cell Counting Kit-8 (CCK8) and Transwell assay. RESULTS HOTTIP expression was increased in NPC tissues. Higher levels of HOTTIP are correlated with lower survival in NPC patients. HOTTIP silencing suppressed the proliferation, cell cycle, migration, and invasion of NPC cells. HOTTIP served as a sponge for miR-4301. miR-4301 expression was significantly inhibited by HOTTIP in NPC cells. miR-4301 overexpression dramatically inhibited NPC cell proliferation, migration, and invasion. CONCLUSIONS This study showed that HOTTIP acts as an oncogene in NPC by sponging miR-4301.

Long Noncoding RNA (lncRNA) MIR22HG Suppresses Gastric Cancer Progression through Attenuating NOTCH2 Signaling

BACKGROUND Long noncoding RNAs (lncRNAs) are important regulators in human disease, including cancers. LncRNA MIR22HG has been shown to inhibit the progression of endometrial carcinoma, lung cancer, and hepatocellular carcinoma. Its role in gastric cancer is unclear. This study investigated MIR22HG effects on gastric cancer. MATERIAL AND METHODS Gastric cancer tissues (n=43) and adjacent normal tissues (n=21) were collected. Patients' 5-year overall survival rate was analyzed. Human normal gastric mucosal cell line (GES-1) and gastric cancer cell lines (MKN-45, AGS, SGC-7901) were cultured. AGS and MKN-45 cells were transfected by pcDNA3 empty vector, pcDNA3-MIR22HG overexpression vector, MIR22HG siRNA and its negative control, NOTCH2 siRNA and its negative control, respectively. Proliferation was explored by CCK-8 assay. Migration and invasion were explored by Transwell. qRT-PCR and western blot were used to investigate mRNA and proteins expression, respectively. RESULTS MIR22HG expression was decreased in gastric cancer tissues and cells (P<0.05). Low MIR22HG expression indicated lower 5-year overall survival rate (P<0.05). Upregulation of MIR22HG inhibited AGS and MKN-45 cell proliferation, migration and invasion (all P<0.05). Downregulation of MIR22HG elevated AGS and MKN-45 cell proliferation, migration, and invasion (all P<0.05). MIR22HG negatively regulated NOTCH2 signaling. Silencing MIR22HG elevated HEY1 and nucleus NOTCH2 expression. Silencing of NOTCH2 suppressed AGS and MKN-45 cells proliferation, migration and invasion (all P<0.05). CONCLUSIONS LncRNA MIR22HG suppressed gastric cancer progression through attenuating NOTCH2 signaling.

Long noncoding RNA LINC01296 promotes cancer-cell proliferation and metastasis in urothelial carcinoma of the bladder

Purpose

Long noncoding RNAs (lncRNAs) play an important role in the tumorigenesis and progression of human cancer. This research was performed to investigate the role of LINC01296 in clinical characteristics, biological functions and molecular mechanisms of bladder cancer.

Materials and methods

In this study, expressions of LINC01296 in cancer tissues and normal tissues were firstly compared using the Gene Expression Profiling Interactive Analysis database. Subsequently, a microarray data analysis was performed to compare lncRNA and mRNA expression profiles in four pairs of human bladder cancer samples. Then, quantitative real-time polymerase chain reaction (qRT-PCR) was used to detect the expression of LINC01296 in bladder cancer tissues. The association between LINC01296 expressions and clinicopathological characteristics of bladder cancer was analyzed by Kaplan–Meier analysis and the Cox proportional-hazard model. The biological functions and molecular mechanisms of LINC01296 in bladder cancer were studied by MTT assay, colony-formation assay, cell cycle analysis, transwell migration assay, wound healing assay, qRT-PCR analysis and Western blot assay.

Results

The expression of LINC01296 was significantly higher in most cancer tissues than that in adjacent normal tissues, and was positively correlated with clinical stages of the cancer (P=0.016), lymph node metastasis (P=0.034), and pathologic grades (P=0.012). The increased level of LINC01296 was associated with a poorer prognosis and shorter survival of the patients. Multivariate analysis showed that the LINC01296 expression was an independent predictor of overall survival in bladder cancer. Additionally, LINC01296 knockdown inhibited the proliferation, migration and progression of cell cycle of bladder cancer cells, and was involved in the regulation of epithelial-mesenchymal transition.

Conclusion

The findings of this study suggested that LINC01296 promotes progression of bladder cancer, and potentially acts as a biomarker and therapeutic target of bladder cancer.

LncRNA LINC00163 upregulation suppresses lung cancer development though transcriptionally increasing TCF21 expression

Long noncoding RNAs (lncRNAs) have been illustrated as vital molecules in regulating human cancer by emerging evidence. LINC00163 is a novel lncRNA without functional definition. In this study, we investigated its role in the tumorigenesis of lung cancer. The results showed that LINC00163 level was significantly downregulated in lung cancer tissues and cell lines by bioinformatics and qRT-PCR analyses. Notably, we observed that LINC00163 expression was lower in metastatic tissues than in non-metastatic cases. Furthermore, higher expression of LINC00163 in patients with lung cancer predicted better prognosis. Gain-of-function assays illustrated that upregulation of LINC00163 dramatically suppressed the proliferation, migration and invasion of lung cancer cells in vitro, whereas promoting apoptosis. Consistently, LINC00163 overexpression impaired tumor propagation in vivo. Mechanical study revealed that LINC00163 recruited ARID1A to the promoter of TCF21 and initiated its expression. In conclusion, we concluded that LINC00163/ARID1A/TCF21 regulatory loop modulated the development of lung cancer, providing a new insight on the mechanism underlying lung cancer progression.

Upregulation of lncRNA FER1L4 suppresses the proliferation and migration of the hepatocellular carcinoma via regulating PI3K/AKT signal pathway

BACKGROUND AND OBJECTIVES

This study aimed to investigate the potential function of FER1L4 in the progression of hepatocellular carcinoma and uncover its underlying molecular mechanism.

METHODS

In the current study, quantitative real-time polymerase chain reaction (qRT-PCR) was conducted to determine the expression profile of FER1L4 in normal liver tissues and hepatocellular carcinoma tissues of human, as well as hepatocellular carcinoma (HCC) cell lines including HL-7702[L-02], HepG-2, Hep3b, and SMMC-7721. Then, HepG-2 cells were transfected with pcDNA3.1-FER1L4 (pcDNA3.1-empty as negative control) for gain-of-function analysis, followed with cell functional abnormality tests. Specifically, colony formation analysis and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazolium bromide experiment were taken advantage to measure the cell proliferation, while cell migration and invasion were evaluated by wound healing assay and transwell experiment respectively. Additionally, cell apoptosis was detected by flow cytometry. Moreover, the effect of FER1L4 on PI3K/AKT signal pathway activation was investigated through analyzing phosphorylation of related proteins, p-AKT/AKT and p-PI3K/PI3K, via Western blot assay.

RESULTS

Downregulation of FER1L4 in hepatocellular carcinoma tissues and cells was demonstrated by qRT-PCR analysis. Besides, FER1L4 overexpression evidently attenuated the cell proliferation, migration and invasion, but prompted cell apoptosis. Importantly, Western blot assays revealed that PII3K/AKT signal pathway were involved in mediating the progression regulation role of FER1L4 in HCC cells.

CONCLUSIONS

Our study suggested that FER1L4 might alleviate progression of hepatocellular carcinoma via blocking PI3K/AKT pathway, which encourages a better understanding of the pathogenesis of HCC and may provide a novel potential therapeutic target for clinical treatment.

LncRNA SLCO4A1-AS1 facilitates growth and metastasis of colorectal cancer through β-catenin-dependent Wnt pathway

Background

Emerging evidence has shown long noncoding RNAs (lncRNAs) exert important roles in colorectal cancer (CRC) tumorigenesis. However, most lncRNAs involved in this process remain undefined and the underlying molecular mechanisms mediated by lncRNAs are largely unknown.

Methods

An unbiased screening was used to identify novel lncRNAs involved in CRC according to an online-available data dataset. In situ hybridization (ISH) and qRT-PCR was used to detect lncRNA expression patterns. CCK8, colony formation, fluorescence activated cell sorter (FACS), transwell, xenograft nude mouse model and western blot assays were used to analyze the functions of SLCO4A1-AS1. RNA-pulldown, western blot, RNA fluorescence in situ hybridization (RNA-FISH) and electrophoretic mobility shift assay (EMSA) assays were utilized to explore the molecular mechanism of SLCO4A1-AS1.

Results

LncRNA SLCO4A1-AS1 was significantly upregulated in CRC tissues and its overexpression was closely related with poor prognosis and tumor metastasis. By knocking down SLCO4A1-AS1, we found that SLCO4A1-AS1 promoted the proliferation, migration, invasion and epithelial–mesenchymal transition (EMT) of CRC cells in vitro, as well as inhibited cell apoptosis. Moreover, SLCO4A1-AS1 dramatically delayed tumor propagation in vivo. Mechanistically, SLCO4A1-AS1 activates Wnt/β-catenin signaling. SLCO4A1-AS1 enhanced the stability of β-catenin by impairing the interaction of β-catenin with GSKβ and inhibiting its phosphorylation. Finally, restoration of β-catenin protein level rescued the proliferation, migration and invasion in SLCO4A1-AS1-depleted CRC cells.

Conclusion

SLCO4A1-AS1 serves as an oncogenic role in CRC through activating Wnt/β-catenin signaling pathway. And SLCO4A1-AS1 might be a useful biomarker for CRC diagnosis and prognosis.

LncRNA DLEU1 contributes to colorectal cancer progression via activation of KPNA3

Background

Accumulating evidences show that long noncoding RNAs (lncRNA) play essential roles in the development and progression of various malignancies. However, their functions remains poorly understood and many lncRNAs have not been defined in colorectal cancer (CRC). In this study, we investigated the role of DLEU1 in CRC.

Methods

Quantitative real-time PCR was used to detect the expression of DLEU1 and survival analysis was adopted to explore the association between DLEU1 expression and the prognosis of CRC patients. CRC cells were stably transfected with lentivirus approach and cell proliferation, migration, invasion and cell apoptosis, as well as tumorigenesis in nude mice were performed to assess the effects of DLEU1 in BCa. Biotin-coupled probe pull down assay, RNA immunoprecipitation and Fluorescence in situ hybridization assays were conducted to confirm the relationship between DLEU1 and SMARCA1.

Results

Here we revealed that DLEU1 was crucial for activation of KPNA3 by recruiting SMARCA1, an essential subunit of the NURF chromatin remodeling complex, in CRC. DLEU1 was indispensible for the deposition of SMARCA1 at the promoter of KPNA3 gene. Increased expression of DLEU1 and KPNA3 was observed in human CRC tissues. And higher expression of DLEU1 or KPNA3 in patients indicates lower survival rate and poorer prognosis. DLEU1 knockdown remarkably inhibited CRC cell proliferation, migration and invasion in vitro and in vivo while overexpressing KPNA3 in the meantime reversed it.

Conclusions

Our results identify DLEU1 as a key regulator by a novel DLEU1/SMARCA1/KPNA3 axis in CRC development and progression, which may provide a potential biomarker and therapeutic target for the management of CRC.

Electronic supplementary material

The online version of this article (10.1186/s12943-018-0873-2) contains supplementary material, which is available to authorized users.

Long noncoding RNA EZR-AS1 promotes tumor growth and metastasis by modulating Wnt/β-catenin pathway in breast cancer

Accumulating evidence has demonstrated that long noncoding RNAs (lncRNAs) serve important roles in tumor development and progression. However, whether lncRNA EZR-AS1 is associated with breast cancer (BC) progression remains unclear. In the present study, reverse transcription-quantitative polymerase chain reaction analysis demonstrated that the expression of EZR-AS1 was significantly upregulated in BC tissues and cell lines. Furthermore, Kaplan-Meier curve analysis revealed that increased EZR-AS1 expression in patients with BC contributes to poor prognosis. Cell counting kit-8 and fluorescence-activated cell sorting experiments indicated that EZR-AS1 knockdown significantly suppressed the proliferation and cell cycle progression of breast cancer cells, while reducing cellular apoptosis. Furthermore, Transwell assays suggested that EZR-AS1 knockdown reduced the migration and invasion ability of BC cells compared with control cells. In the present study, it was observed that EZR-AS1 interacts with β-catenin to prevent degradation. EZR-AS1 knockdown resulted in β-catenin downregulation and inactivation of the Wnt/β-catenin pathway. Rescue assays revealed that β-catenin overexpression reversed the effects of EZR-AS1 knockdown on BC cell proliferation, apoptosis, migration and invasion. In conclusion, the results of the present study demonstrate that EZR-AS1 serves as an oncogene in BC via activating the Wnt/β-catenin pathway. This suggests that EZR-AS1 may be a therapeutic target for BC treatment.

Long noncoding RNA TMEM75 promotes colorectal cancer progression by activation of SIM2

Colorectal cancer (CRC) is one of the most frequent cancers worldwide and leads to a great many deaths each year. However, the underlying mechanisms that regulate colorectal cancer development and progression remain elusive. Here we identified an uncharacteristic long noncoding RNA TMEM75 that was upregulated in colorectal cancer compared to non-tumor tissues. We found that TMEM75 expression levels are positively correlated with advanced clinical stage. TMEM75 significantly inhibited the proliferation, migration, and invasion of CaCo2 and HCT116 cells in vitro. Moreover, TMEM75 silence delayed tumor growth in vivo. Mechanistically, TMEM75 was demonstrated to initiate the expression of transcription factor SIM2. We also found that the expression of SIM2 was upregulated and positively correlated that of TMEM75 in colorectal cancer tissues. Furthermore, ectopic expression of SIM2 rescued TMEM75 depletion-induced inhibition on cell proliferation, migration and invasion in colorectal cancer. Altogether, our findings indicated that TMEM75 functions as an oncogene relying on activation of SIM2 in colorectal cancer for the first time.

lncAKHE enhances cell growth and migration in hepatocellular carcinoma via activation of NOTCH2 signaling

Hepatocellular carcinoma is the sixth most common cancer and gives rise to numerous deaths around the world every year. However, the molecular mechanism that controls hepatocarcinogenesis remains largely unknown. Here we found out an uncharacterized long noncoding RNA named lncAKHE. We found that lncAKHE was highly expressed in hepatocellular carcinoma tissues. lncAKHE depletion remarkably impaired the abilities of cell proliferation, migration, and invasion in hepatocellular carcinoma while promgoogoting cell apoptosis. Moreover, higher expression level of lncAKHE in hepatocellular carcinoma tissues was associated with more clinical severity and lower survival rates. Mechanistically, lncAKHE cooperated with YEATS4 to enhance the activation of NOTCH2 signaling which is usually abnormally upregulated in hepatocellular carcinoma. In conclusions, our study showed that lncAKHE may promote tumor progression in HCC and serve as a novel target for HCC treatment.

Long noncoding RNA LINC01296 promotes tumor growth and progression by sponging miR-5095 in human cholangiocarcinoma

The aim of the present study was to elucidate whether, and how, long intergenic non-protein coding RNA 1296 (LINC01296) is involved in the modulation of human cholangiocarcinoma (CCA) development and progression. Microarray data analysis and reverse transcription-quantitative polymerase chain reaction analysis demonstrated that LINC01296 was significantly upregulated in human CCA compared with nontumor tissues. Furthermore, the expression of LINC01296 in human CCA was positively associated with tumor severity and clinical stage. Knockdown of LINC01296 dramatically suppressed the viability, migration and invasion of RBE and CCLP1 cells, and promoted cell apoptosis in vitro. Furthermore, LINC01296 knockdown inhibited tumor growth in a xenograft model. Mechanistically, LINC01296 was demonstrated to sponge microRNA-5095 (miR-5095), which targets MYCN proto-oncogene bHLH transcription factor (MYCN) mRNA in human CCA. By inhibition of miR-5095, LINC01296 overexpression upregulated the expression of MYCN and promoted cell viability, migration and invasion in CCA cells. The results reveal that the axis of LINC01296/miR-5095/MYCN may be a mechanism to regulate CCA development and progression.

Long non-coding RNA CRNDE as a potential prognostic biomarker in solid tumors: A meta-analysis

BACKGROUND AND AIM

Long non-coding RNA colorectal neoplasia differentially expressed (CRNDE) has been demonstrated to be highly expressed in many malignant tumors; however, the role of CRNDE in cancer remains undetermined because of limitations in sample size. We conducted a meta-analysis to assess the role of CRNDE in cancer.

METHODS

PubMed, Medline, Cochrane Library, Web of Science, EMBASE database, Ovid, Chinese CNKI, and Chinese WanFang database were systematically searched. The relation between CRNDE and the clinicopathological characteristics and prognosis of patients with cancer was determined using pooled odds ratios (ORs) and hazard ratios (HRs) with 95% confidence interval (CI).

RESULTS

Thirteen studies with 1570 patients were included. The pooled results indicated that high CRNDE expression was related to lymph node metastasis (YES vs. NO: OR = 3.50, 95% CI = [1.05, 8.09]) and TNM stage (I + II vs. III + IV: OR = 0.26, 95% CI = [0.18, 0.37]) but not to gender, tumor size, and differentiation. High CRNDE expression indicated poor overall survival (OS) (HR = 2.06, 95% CI = [1.66, 2.47]). CRNDE could be an independent predictive factor for OS (HR = 1.62, 95% CI = [1.15, 2.08]) in patients with cancer.

CONCLUSION

Therefore, high CRNDE expression was associated with advanced clinicopathological characteristics, and CRNDE could be used as a reliable prognostic biomarker in human cancer. However, more high-quality studies with a large sample size are needed to support this meta-analysis.

The Role of Long Non-Coding RNAs in Hepatocarcinogenesis

Whole-transcriptome analyses have revealed that a large proportion of the human genome is transcribed in non-protein-coding transcripts, designated as long non-coding RNAs (lncRNAs). Rather than being “transcriptional noise”, increasing evidence indicates that lncRNAs are key players in the regulation of many biological processes, including transcription, post-translational modification and inhibition and chromatin remodeling. Indeed, lncRNAs are widely dysregulated in human cancers, including hepatocellular carcinoma (HCC). Functional studies are beginning to provide insights into the role of oncogenic and tumor suppressive lncRNAs in the regulation of cell proliferation and motility, as well as oncogenic and metastatic potential in HCC. A better understanding of the molecular mechanisms and the complex network of interactions in which lncRNAs are involved could reveal novel diagnostic and prognostic biomarkers. Crucially, it may provide novel therapeutic opportunities to add to the currently limited number of therapeutic options for HCC patients. In this review, we summarize the current status of the field, with a focus on the best characterized dysregulated lncRNAs in HCC.

Long Noncoding RNA CCAL Promotes Papillary Thyroid Cancer Progression by Activation of NOTCH1 Pathway

Long noncoding RNA CCAL has been reported to promote tumor progression in various human cancers, including hepatocellular carcinoma, osteosarcoma, and colorectal cancer. However, the role of CCAL in papillary thyroid cancer remains largely unknown. In the present study, we found that the expression of CCAL was upregulated in papillary thyroid tumor tissues compared to adjacent normal tissues. Moreover, the expression of CCAL was positively related with papillary thyroid cancer severity and TNM stage and predicated poor prognosis. Besides, we found that knockdown of CCAL significantly inhibited papillary thyroid cancer cell proliferation, migration, and invasion in vitro and reduced tumor growth and metastasis in vivo. We found that knockdown of CCAL dramatically decreased the expression of NOTCH1 and suppressed the activation of the NOTCH1 signaling pathway. Furthermore, overexpression of NOTCH1 rescued the proliferation, migration, and invasion in papillary thyroid cancer cells. Taken together, our data indicated that CCAL promoted papillary thyroid cancer development and progression by activation of the NOTCH1 pathway, which provided a new insight on the design of therapeutic targets.

Long Noncoding RNA FGFR3-AS1 Promotes Hepatocellular Carcinoma Carcinogenesis via Modulating the PI3K/AKT Pathway

Hepatocellular carcinoma (HCC) as one of the most refractory cancers leads to high mortality worldwide. Long noncoding RNAs have been widely acknowledged as important biomarkers and therapeutic targets in HCC. In this study, we investigated the effects of long noncoding RNA FGFR3-AS1 on tumor growth and metastasis in HCC. First, we found that the expression of FGFR3-AS1 was upregulated about threefold in HCC samples and cell lines. We knocked down FGFR3-AS1 in Huh7 and Hep3B cells and found that FGFR3-AS1 knockdown significantly inhibited cell proliferation but induced apoptosis. Moreover, FGFR3-AS1 knockdown led to more HCC cells arrested in the G₀ stage. FGFR3-AS1 knockdown significantly inhibited cell migration and invasion. Additionally, we found that FGFR3-AS1 silencing dramatically delayed tumor growth in vivo. We found that, mechanistically, FGFR3-AS1 silencing decreased the activation of the PI3K/AKT signaling pathway. Taken together, our data demonstrated the pro-oncogenic role of FGFR3-AS1 in HCC and suggested that FGFR3-AS1 may serve as a novel biomarker for the diagnosis and therapeutic target for HCC treatment.

Long noncoding RNA SNHG15 promotes human breast cancer proliferation, migration and invasion by sponging miR-211-3p

Long non-coding RNAs (lncRNA) have been demonstrated to act as essential regulators in the development and progression of breast cancer. In our study, we found that long noncoding RNA SNHG15 was highly expressed in breast cancer tissues and cell lines. And the expression of SNHG15 was correlated with TNM stage, lymphnode metastasis and survival in breast cancer patients. SNHG15 knockdown significantly inhibited the proliferation and induced apoptosis in breast cancer cells in vitro and in vivo. Besides, SNHG15 downregulation suppressed cell migration and invasion in MCF-7 and BT-20 cells, and inhibited epithelial-mesenchymal transition (EMT). In mechanism, we found that SNHG15 acted as a competing endogenous RNA to sponge miR-211-3p, which was downregulated in breast cancers and inhibited cell proliferation and migration. Our results showed that there was a negative correlation between SNHG15 and miR-211-3p expression in breast cancer patients. Collectively, we, for the first time, revealed the functions of SNHG15 and miR-211-3p in breast cancer.