H19 promotes non‐small‐cell lung cancer (NSCLC) development through STAT3 signaling via sponging miR‐17

LncRNAs in Non-Small-Cell Lung Cancer

Lung cancer is associated with a high mortality, with around 1.8 million deaths worldwide in 2018. Non-small-cell lung cancer (NSCLC) accounts for around 85% of cases and, despite improvement in the management of NSCLC, most patients are diagnosed at advanced stage and the five-year survival remains around 15%. This highlights a need to identify novel ways to treat the disease to reduce the burden of NSCLC. Long non-coding RNAs (lncRNAs) are non-coding RNA molecules longer than 200 nucleotides in length which play important roles in gene expression and signaling pathways. Recently, lncRNAs were implicated in cancer, where their expression is dysregulated resulting in aberrant functions. LncRNAs were shown to function as both tumor suppressors and oncogenes in a variety of cancer types. Although there are a few well characterized lncRNAs in NSCLC, many lncRNAs remain un-characterized and their mechanisms of action largely unknown. LncRNAs have success as therapies in neurodegenerative diseases, and having a detailed understanding of their function in NSCLC may guide novel therapeutic approaches and strategies. This review discusses the role of lncRNAs in NSCLC tumorigenesis, highlighting their mechanisms of action and their clinical potential.

A novel mRNA-miRNA-lncRNA competing endogenous RNA triple sub-network associated with prognosis of pancreatic cancer

Background: Recently, increasing evidence has uncovered the roles of mRNA-miRNA-lncRNA network in multiple human cancers. However, a systematic mRNA-miRNA-lncRNA network linked to pancreatic cancer prognosis is still absent. Methods: Differentially expressed genes (DEGs) were first identified by mining GSE16515 and GSE15471 datasets. DAVID database was utilized to conduct functional enrichment analysis. Protein-protein interaction (PPI) network was built using STRING database, and hub genes were identified by Cytoscape plug-in CytoHubba. Upstream miRNAs and lncRNAs of mRNAs were predicted by miRTarBase and miRNet, respectively. Expression, survival and correlation analysis for genes, miRNAs and lncRNAs were performed via GEPIA, Kaplan-Meier plotter and starBase. Results: 734 and 180 upregulated and downregulated significant DEGs were identified, respectively. Functional enrichment analysis revealed that they were significantly enriched in focal adhesion, pathways in cancer and metabolic pathways. According to node degree, hub genes in the PPI networks were screened, such as TGFB1 and ALB. Among the top 20 hub genes, 7 upregulated genes and 2 downregulated hub genes had significant prognostic values in pancreatic cancer. 33 miRNAs were predicted to target the 9 key genes. But only high expression of 8 miRNAs indicated favorable prognosis in pancreatic cancer. Then, 90 lncRNAs were predicted to potentially bind to the 8 miRNAs. SCAMP1, HCP5, MAL2 and LINC00511 were finally identified as key lncRNAs. By combination of results from expression, survival and correlation analysis demonstrated that MMP9/ITGB1-miR-29b-3p-HCP5 competing endogenous RNA (ceRNA) sub-network was linked to prognosis of pancreatic cancer. Conclusions: In a word, we established a novel mRNA-miRNA-lncRNA sub-network, among which each RNA may be utilized as a prognostic biomarker of pancreatic cancer.

Exosomal Long Non-Coding RNAs in Lung Diseases

Within the non-coding genome landscape, long non-coding RNAs (lncRNAs) and their secretion within exosomes are a window that could further explain the regulation, the sustaining, and the spread of lung diseases. We present here a compilation of the current knowledge on lncRNAs commonly found in Chronic Obstructive Pulmonary Disease (COPD), asthma, Idiopathic Pulmonary Fibrosis (IPF), or lung cancers. We built interaction networks describing the mechanisms of action for COPD, asthma, and IPF, as well as private networks for H19, MALAT1, MEG3, FENDRR, CDKN2B-AS1, TUG1, HOTAIR, and GAS5 lncRNAs in lung cancers. We identified five signaling pathways targeted by these eight lncRNAs over the lung diseases mentioned above. These lncRNAs were involved in ten treatment resistances in lung cancers, with HOTAIR being itself described in seven resistances. Besides, five of them were previously described as promising biomarkers for the diagnosis and prognosis of asthma, COPD, and lung cancers. Additionally, we describe the exosomal-based studies on H19, MALAT1, HOTAIR, GAS5, UCA1, lnc-MMP2-2, GAPLINC, TBILA, AGAP2-AS1, and SOX2-OT. This review concludes on the need for additional studies describing the lncRNA mechanisms of action and confirming their potential as biomarkers, as well as their involvement in resistance to treatment, especially in non-cancerous lung diseases.

Noncoding RNAs in Vascular Diseases

The advent of deep sequencing technologies led to the identification of a considerable amount of noncoding RNA transcripts, which are increasingly recognized for their functions in controlling cardiovascular diseases. MicroRNAs have already been studied for a decade, leading to the identification of several vasculoprotective and detrimental species, which might be considered for therapeutic targeting. Other noncoding RNAs such as circular RNAs, YRNAs, or long noncoding RNAs are currently gaining increasing attention, and first studies provide insights into their functions as mediators or antagonists of vascular diseases in vivo. The present review article will provide an overview of the different types of noncoding RNAs controlling the vasculature and focus on the developing field of long noncoding RNAs.

Inhibition of LncRNAH19 has the effect of anti-tumour and enhancing sensitivity to Gefitinib and Chemotherapy in Non-small-cell lung cancer in vivo

Lung cancer is one of the most common malignant diseases, which ranked first in both men and women malignancies worldwide. The survival rate of non-small-cell lung cancer (NSCLC) has been limited with distant metastasis and shortage of effective chemotherapeutics in recent years. Thus, novel therapeutic strategies for NSCLC are urgently explored. Here, we showed that inhibition of H19 effectively inhibited the progression of NSCLC. Moreover, down-regulation of H19 treatment significantly enhanced the levels of PTEN and PDCD4, while suppressed the expressions of NFIB in NSCLC. Furthermore, down-regulation of H19 combined with Gefitinib treatment significantly increased the levels of PTEN and PDCD4, while decreased the expression levels of NFIB. Moreover, the results showed that Gefitinib treatment significantly reduced the shH19-mediated miR-21 expression levels. Our results showed that down-regulation of H19 combined with Gefitinib administration significantly improved the effect of shH19 treatment alone on the progression of NSCLC, which was involved in the activation of PTEN signalling pathway in NSCLC in vivo. Therefore, these findings might indicate a novel molecular mechanism, which could provide a new potential combination of therapeutic method in NSCLC.

LINC00210 plays oncogenic roles in non-small cell lung cancer by sponging microRNA-328-5p

Long noncoding RNA (lncRNA) has an important role in regulating non-small cell lung cancer (NSCLC) progression. The present study aimed to investigate the effect of LINC00210 in NSCLC progression in order to provide a novel treatment target for patients with NSCLC. A total of 39 NSCLC patients were obtained and divided into LINC00210 high expression and low expression groups. Subsequently, the 5-year survival rate from this patient cohort was analyzed. The SK-MES-1 and A549 NSCLC and the human 16-HBE bronchial epithelial cell lines were utilized to investigate expression level of LIN00210. A549 cells were used to investigate cell proliferation, migration and invasive abilities using Cell Counting kit 8, Transwell and Matrigel assays, respectively. In addition, the luciferase reporter gene assay was performed to investigate the potential target of LINC00210. Reverse transcription-quantitative PCR was used to determine LINC00210 and microRNA (miR)-328-5p expression levels in NSCLC tissues and tumor cell lines (SK-MES-1 and A549). The results demonstrated that LINC00210 was upregulated in NSCLC tissues and cell lines compared with that in normal tissues and 16-HBE cells, and that LINC00210 expression was associated with a poor prognosis in patients with NSCLC (P<0.05). Furthermore, A549 cell transfection with small interfering (si)LINC00210#1 and siLINC00210#2 induced a significant decrease in cell proliferation, and migratory and invasive abilities compared with that in the control groups (P<0.05). In addition, miR-328-5p overexpression was stimulated by knockdown of LINC00210. Furthermore, A549 cells transfected with siLINC00210#1 and miR-328-5p inhibitor exhibited a significant increase in cell proliferation, and migratory and invasive ability compared with that in A549 cells transfected with siLINC00210#1. These findings suggest that LINC00210 may serve as an oncogenic role in NSCLC by sponging miR-328-5p.

Knockdown of Linc00511 inhibits TGF-β-induced cell migration and invasion by suppressing epithelial-mesenchymal transition and down-regulating MMPs expression

Epithelial mesenchymal transition (EMT) is a critical step in cancer metastasis. Some evidences have been provided to verify up-regulation of linc00511 in multiple cancers and oncogenic roles during cancer malignant process. But, the roles of linc00511 on the metastasis of lung cancer are still largely unclear. Our study aims to reveal the functional effects of linc00511 on TGF-β1-induced EMT in lung cancer. Our results showed that knockdown of linc00511 significantly inhibited TGF-β1-induced migration and invasion and down-regulated the mRNA and protein levels of MMP2, MMP9 and MMP12 in TGF-β1 treated SPCA1 and H1975 cells. Also, western blotting results showed that inhibition of linc00511 remarkably suppressed TGF-β1-induced N-cadherin, Vimentin and snail and increased E-cadherin expression in SPCA1 and H1975 cells. Noteworthy, we further found that inhibition of linc00511 could down-regulate TGF-β1-induced ZEB2 mRNA and protein levels by sponging miR-183-5p in SPCA1 and H1975 cells. Taken together, our findings suggested knockdown linc00511 suppressed TGF-β1-induced migration and invasion via inhibiting EMT and MMPs in lung cancer cells.

The prognostic value of long non-coding RNA H19 in various cancers: A meta-analysis based on 15 studies with 1584 patients and the Cancer Genome Atlas data

BACKGROUND

Recent studies have shown that long noncoding RNA (lncRNA) H19 is aberrantly expressed in various cancers. However, the prognostic significance of H19 in cancer patients remains to be elucidated. Here, we designed and conducted a meta-analysis to evaluate the prognostic value of this lncRNA for malignant solid neoplasms.

METHODS

Relevant publications were collected from PubMed, Cochrane Library, Web of Science, and Embase databases. The relevant survival data of patients with H19-associated cancers were downloaded from The Cancer Genome Atlas (TCGA) project. Statistically significant relationships between H19 expression levels and overall survival were analyzed by hazard ratios (HRs) and corresponding 95% confidence intervals (CIs).

RESULTS

A total of 15 studies with 1584 patients were ultimately included for this literature meta-analysis. An elevated level of H19 expression was found to be negatively correlated with the overall survival (OS) (HR = 1.62, 95% CI = 1.36-1.93, P < .001) in various cancers. Abnormal H19 expression was also positively correlated with poor tumor differentiation (P < .0001), more advanced clinical stage (P < .0001), earlier lymph node metastasis (P < .0001), and earlier distant metastasis (P < .05). The relationship between elevated H19 expression and overall survival was further validated by a TCGA dataset consisting of 7462 cancer patients (HR = 1.12, 95% CI = 1.03-1.22, P < .05).

CONCLUSION

Our study indicates that H19 expression is closely relevant to clinical outcome and suggests that lncRNA H19 could be a crucial prognostic biomarker for certain carcinoma types.

H19 lncRNA: Roles in tumorigenesis

H19 is a long non-coding RNA [lncRNA] which was firstly described as an oncofetal transcript. The imprinted gene is normally expressed from the maternal allele. However, this pattern of imprinting is dysregulated in several cancers leading to aberrant up-regulation of H19 in malignant tissues. Several studies have utilized this aberrant expression pattern to find specific biomarkers for detection of cancer in tumoral tissues or peripheral blood. Moreover, single nucleotide polymorphisms within H19 have been associated with risk of oral squamous cell carcinoma, hepatocellular carcinoma, breast cancer, bladder cancer, gastric cancer and colorectal cancer. Taken together, H19 is regarded as a biomarker for cancer and a putative therapeutic target in these human disorders.

LncRNA GMDS-AS1 inhibits lung adenocarcinoma development by regulating miR-96-5p/CYLD signaling

According to the global cancer statistic, lung cancer is one of the most dangerous tumors, which poses a serious threat to human health. Exploration the mechanism of lung cancer and new targeted therapeutic measures is always the hot topic. Long noncoding RNA (lncRNA) is an important factor affecting the development of tumors. However, the research on the mechanism of lncRNA in the progress of lung cancer needs to be further expanded. In this study, we found that the expression of lncRNA GMDS-AS1 was significantly reduced in lung adenocarcinoma (LUAD) tissues and cells. Upregulated GMDS-AS1 can significantly inhibit the proliferation of LUAD cells and promote cell apoptosis in vitro and in vivo. The results indicate that GMDS-AS1 acts as a tumor suppressor gene to affect the development of LUAD. Further studies revealed that GMDS-AS1 is a target gene of miR-96-5p, and GMDS-AS1 regulates proliferation and apoptosis of LUAD cells in association with miR-96-5p. In addition, we also confirmed that CYLD lysine 63 deubiquitinase (CYLD) is also a target gene of miR-96-5p. Through various validations, we confirmed that GMDS-AS1 can act as a ceRNA to upregulate the expression of CYLD by sponging miR-96-5p. Moreover, the intervention of GMDS-AS1/miR-96-5p/CYLD network can regulate the proliferation and apoptosis of LUAD cells. In this study, we revealed that the GMDS-AS1/miR-96-5p/CYLD network based on ceRNA mechanism plays an important role in the development of LUAD and provides a new direction and theoretical basis for targeted therapy of LUAD.

Current Landscape of Epigenetics in Lung Cancer: Focus on the Mechanism and Application

Lung cancer is the leading cause of cancer-related mortality worldwide. Tumorigenesis involves a multistep process resulting from the interactions of genetic, epigenetic, and environmental factors. Genome-wide association studies and sequencing studies have identified many epigenetic alterations associated with the development of lung cancer. Epigenetic mechanisms, mainly including DNA methylation, histone modification, and noncoding RNAs (ncRNAs), are heritable and reversible modifications that are involved in some important biological processes and affect cancer hallmarks. We summarize the major epigenetic modifications in lung cancer, focusing on DNA methylation and ncRNAs, their roles in tumorigenesis, and their effects on key signaling pathways. In addition, we describe the clinical application of epigenetic biomarkers in the early diagnosis, prognosis prediction, and oncotherapy of lung cancer. Understanding the epigenetic regulation mechanism of lung cancer can provide a new explanation for tumorigenesis and a new target for the precise treatment of lung cancer.

Long non-coding RNA in lung cancer

Lung cancer is the leading cause of cancer-related death worldwide. Owing to the difficulty in early diagnosis and the lack of effective treatment strategies, the 5-year survival rates for lung cancer remain very low. With the development of whole genome and transcriptome sequencing technology, long non-coding RNA (lncRNA) has attracted increasing attention. LncRNAs regulate gene expression at the epigenetic, transcriptional and post-transcriptional levels and are widely involved in a variety of diseases, including tumorigenesis. In lung cancer studies, multiple differentially expressed lncRNAs have been identified; several lncRNAs were identified as oncogenic lncRNAs with tumor-driving effects, while other lncRNAs play a role in tumor inhibition and are called tumor-suppressive lncRNAs. These tumor-suppressive lncRNAs are involved in multiple physiological processes such as cell proliferation, apoptosis, and metastasis and thus participate in tumor progression. In this review, we discussed the oncogenic and tumor-suppressive lncRNAs in lung cancer, as well as their biological functions and regulatory mechanisms. Furthermore, we found the potential significance of lncRNAs in clinical diagnosis and treatment.

Association between polymorphism in CDKN2B-AS1 gene and its interaction with smoking on the risk of lung cancer in a Chinese population

Background

Long non-coding RNAs became the hot spots in the carcinogenesis of various tumors. This case-control study evaluated the association between the rs2151280 in lncRNA CDKN2B-AS1 and lung cancer risk.

Methods

This study included 507 lung cancer patients and 542 healthy individuals. Odds ratios and their 95% confidence intervals were calculated by unconditional logistic regression analysis to evaluate the association between the rs2151280 and lung cancer risk.

Results

Compared with individuals carrying TT genotype, individuals carrying CC genotype of rs2151280 had a decreased risk of lung cancer (OR = 0.640, 95%CI = 0.421–0.972, P = 0.036). In the recessive model, rs2151280 CC genotype was observed to reduce the risk of lung cancer (OR = 0.684). C allele was associated with non-small cell lung cancer risk (OR = 0.674). The rs2151280 was significantly associated with lung adenocarcinoma risk (CCvsTT: OR = 0.567, 95%CI = 0.333–0.965, P = 0.037; CCvsTC+TT: OR = 0.543, 95%CI 0.330–0.893, P = 0.016, respectively). However, there was no significant association between rs2151280 and lung squamous cell carcinoma risk in five models. The quantitative analysis suggested that there were no significant interactions of rs2151280 with smoking exposure to lung cancer susceptibility.

Conclusions

This hospital-based case-control study suggested that CDKN2B-AS1 rs2151280 T>C was associated with the risk of lung cancer.

The role of long non-coding RNA H19 in breast cancer

Breast cancer is the most common malignant tumor in women in the majority of countries, such as China, Britain and Australia, and its morbidity and mortality rates remain very high. Long non-coding RNAs (lncRNAs) are non-coding RNAs (ncRNAs) >200 nucleotides in length that lack open reading frames. LncRNA H19 is a transcription product of the H19 gene, and the aberrant expression of H19 can be demonstrated in various types of tumor cell. The purpose of the present review was to elaborate the role of H19 in breast cancer. H19 can regulate gene expression in breast cancer at multiple levels, including epigenetic, transcriptional and posttranscriptional. The abnormal expression of H19 is closely associated with the tumorigenesis and progression of breast cancer via different underlying molecular mechanisms, such as encoding microRNA-675, competing endogenous RNA regulation and interacting with MYC. A large number of clinical studies have suggested that H19 can serve as a potential biomarker for the diagnosis of breast cancer. High expression levels of H19 increases the drug resistance of breast cancer cells and is associated with poor prognosis within patients with breast cancer. Therefore, serum H19 levels may have momentous significance in the clinical setting.

Bioinformatics analysis of LINC00426 expression in lung cancer and its correlation with patients' prognosis

Background

To investigate the expression of long noncoding RNA (lncRNA) LINC00426 (long intergenic nonprotein coding RNA 426) in non‐small cell lung cancer (NSCLC) patients and its correlation with their prognosis.

Methods

The expression of long noncoding RNA LINC00426 of non‐small cell lung cancer (NSCLC) in The Cancer Genome Atlas (TCGA) database was screened. According to the expression level of LINC00426 in tumor tissue of NSCLC patients, the patients were divided into high and low LINC00426 expression groups. The correlation between LINC00426 expression group and the prognosis of the patient was analyzed by log‐rank test. A total of 72 NSCLC patients who had undergone surgery were retrospectively included in this study. LINC00426 relative expression of tumor and normal lung tissue of the included 72 NSCLC patients were examined by real‐time quantitative PCR assay. The correlation between LINC00426 expression and the patients’ clinical characteristics were also evaluated.

Results

LINC00426 relative expression was not statistically different between cancer and normal tissue (P > 0.05) of NSCLC patients in the TCGA database. The amplification and deep deletion mutation of LINC00426 gene was found in 0.5% of NSCLC patients. The overall survival (OS) of the LINC00426 high expression group was significantly higher than that of the low expression group (HR = 0.81, P = 0.044), while there was no significant difference between the high and low expression group (HR = 0.97, P = 0.82) for disease‐free survival (DFS). LINC0042646 expression level was elevated in 46 cases in normal lung tissue compared to the tumor tissue of the 72 NSCLC patients. LINC0042646 expression level was significantly correlated with the clinical stage (P < 0.05).

Conclusion

Long noncoding RNA LINC00426 was downregulated in the tumor tissue of NSCLC patients and correlated with poor prognosis.

Construction of a competing endogenous RNA network using differentially expressed lncRNAs, miRNAs and mRNAs in non‑small cell lung cancer

The competing endogenous RNA (ceRNA) network is crucial for the development and progression of tumors, including non-small cell lung cancer (NSCLC). However, what type of ceRNA network regulates NSCLC has not been clarified. The present study aimed to elucidate the long non-coding RNA (lncRNA)/microRNA (miRNA)/mRNA ceRNA network in NSCLC, particularly for the significance of lncRNAs in NSCLC. NSCLC-specific differentially expressed lncRNAs, miRNAs and mRNAs in the Cancer Genome Atlas (TCGA) were analyzed and their relationship was analyzed by a ceRNA network. Their potential functions of differentially expressed mRNAs were analyzed by Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG). Furthermore, the expression levels of four selected lncRNAs in TCGA were determined and their associated survival of patients was examined. In addition, the expression profiles of these four lncRNAs in 48 NSCLC specimens and cell lines, their cellular distribution and associated clinical parameters were examined. We successfully constructed a ceRNA network, including 113 lncRNAs, 12 miRNAs and 36 mRNAs differentially expressed between NSCLC and non-tumor tissues. LINC00525, MED4-AS1, STEAP2-AS1 and SYNPR-AS1 lncRNAs were selected and validated for their association with the survival of NSCLC patients. The expression of these lncRNAs was upregulated in 48 NSCLC tissues and was varying in NSCLC cells. While LINC00525 was mainly expressed in the cytoplasm, MED4-AS1 was in both the nucleus and cytoplasm of A549 cells. In addition, the expression of LINC00525 was significantly associated with smoking history (P<0.05); MED4-AS1 was significantly associated with women, poor differentiation and lymph node metastasis (P<0.05); STEAP2-AS1 was significantly associated with women (P<0.01); and SYNPR-AS1 was significantly associated with women and adenocarcinoma (P<0.05). These lncRNAs may be valuable biomarkers for prognosis of NSCLC and the ceRNA network may provide new insights in the pathogenesis of NSCLC.

The characteristics of lung cancer in Xuanwei County: A review of differentially expressed genes and noncoding RNAs on cell proliferation and migration

The occurrence of lung cancers is the highest in Xuanwei County, Yunnan province, China, especially among nonsmoking women. Domestic combustion of smoky coal induces serious indoor air pollution and is considered to be the main cause of human lung cancers. The occurrence of lung cancer in Xuanwei County has unique characteristics, such as the high morbidity in nonsmoking women or people with no family history. In the present review, we summarize advances in identification of differentially expressed genes, regulatory lncRNAs and miRNAs in cell proliferation and migration of lung cancers in Xuanwei County. Moreover, several regulatory differentially expressed genes (DEGs) or noncoding RNAs have diagnostic and prognostic significance for lung cancers in Xuanwei County and have the potential to serve as biomarkers.

The identification of CRNDE, H19, UCA1 and HOTAIR as the key lncRNAs involved in oxaliplatin or irinotecan resistance in the chemotherapy of colorectal cancer based on integrative bioinformatics analysis

With the increasing rate of chemoresistance in colorectal cancer (CRC) patients with advanced tumor stages, it is a matter of urgent importance to delineate the factors involved in the drug resistance process. In this study, gene expression profiles were downloaded from the Gene Expression Omnibus database and an integrated analysis with the aim of detecting hub long non‑coding RNAs (lncRNAs) and their regulated, differentially expressed genes (DEGs) during treatment with oxaliplatin (OxPt) or irinotecan was conducted. A total of seven differentially expressed lncRNAs were correlated with OxPt resistance and 21 were correlated with resistance to SN‑38, the active metabolite of irinotecan. Gene Ontology annotation and Kyoto Encyclopedia of Genes and Genomes pathway enrichment analysis confirmed that drug resistance was strongly associated with an imbalance between cell proliferation and apoptosis, cell energetic metabolism under hypoxic conditions, and angiogenesis. Moreover, a large number of lncRNA‑targeted DEGs were located in extracellular exosomes. Further analyses identified four hub lncRNAs involved in the process of drug resistance, including CRNDE, H19, UCA1 and HOTAIR, which are predictive factors for treatment sensitivity. Among them, HOTAIR stands out as a strong factor, the elevated expression of which is also associated with advanced tumor node and metastasis stage and poor CRC disease prognosis.

Development of a 21-miRNA Signature Associated With the Prognosis of Patients With Bladder Cancer

Objective: To develop a prognostic signature for patients with bladder cancer (BC).

Methods: We identified differentially expressed miRNAs between normal bladder tissue and bladder cancer in the TCGA-BCLA dataset and evaluated prognostic values of these miRNAs. Then, a 21-miRNA signature was constructed based on the results of Cox proportional hazards regression model. Furthermore, functional enrichment analyses were conducted to explore the potential effects of the target genes of these 21 miRNAs.

Results: Seventy six differentially expressed miRNAs were identified, among which 21 miRNAs including hsa-let-7c, mir-143, mir-944, mir-192, mir-590, mir-490, mir-141, mir-93, mir-1-2, mir-200c, mir-133a-1, mir-1-1, mir-133b, mir-20a, mir-185, mir-19a, mir-19b-2, mir-19b-1, mir-17, mir-15a, and mir-133a-2 were demonstrated to be significantly correlated with the overall survival (OS) of bladder cancer patients using Kaplan-Meier survival analysis and Log-rank test. The results of Chi-square test and multivariable logistic regression analysis showed that the 21-miRNA signature was significantly associated with the diagnosis type and T stage of bladder cancer. Univariate and multivariable survival analyses indicated that the 21-miRNA signature was an independent factor in predicting the overall survival of patients with bladder cancer. The results of functional enrichment analysis suggested that the target genes of these 21 miRNAs were mostly enriched in critical cancer-related biological processes and pathways, and the PPI network suggested that 60 targeted genes interacted with a minimum of 30 genes were at the hub of the whole network. In addition, we performed a multivariate nomogram and decision curve analysis (DCA) to evaluate the clinical application of 21-microRNA signature.

Conclusion: We introduced a 21-miRNA signature which was associated the prognosis of patients of bladder cancer, and inspirational ideas for the future basic and clinical exploration.

Long non‑coding RNAs in lung cancer: Regulation patterns, biologic function and diagnosis implications (Review)

Lung cancer is the most common malignancy with the highest mortality worldwide. Emerging research has demonstrated that long non-coding RNAs (lncRNAs), a key genomic product, are commonly dysregulated in lung cancer and have significant functions in lung cancer initiation, progression and therapeutic response. lncRNAs may interact with DNA, RNA or proteins, as tumor suppressor genes or oncogenes, to regulate gene expression and cell signaling pathways. In the present review, first a summary was presented of the causal effects of dysregulated lncRNAs in lung cancer. Next, the function and specific mechanisms of lncRNA-mediated tumorigenesis, metastasis and drug resistance in lung cancer were discussed. Finally, the potential roles of lncRNAs as biomarkers for lung cancer were explored.

The miRNA hsa-miR-6515-3p potentially contributes to lncRNA H19-mediated-lung cancer metastasis

Aberrant expression of long noncoding RNAs (lncRNAs) contributes to all phenotypes of cancer including metastasis, which is a major cause of death in many advanced malignancies. One particular lncRNA, H19, is found to be a crucial player in cancer progression by modulating multiple microRNAs (miRNAs). In this study, we screened miRNAs possibly associated with H19 using lung carcinoma cell lines and patient with lung cancer tissues, and selected one possible hit, hsa‐miR‐6515‐3p, to perform in vitro functional assays. Its inhibition leads to decreased proliferation and migration of SPC‐A1 lung cancer cells and is in good correlation with H19‐knockdown groups. These results indicate that H19 may be an epigenetic regulator of miR‐6515‐3p, and its dysregulation may contribute to lung cancer progression and metastasis.

Downregulation of fibroblast growth factor 5 inhibits cell growth and invasion of human nonsmall-cell lung cancer cells

The morbidity and mortality rates of nonsmall-cell lung cancer (NSCLC) have increased in recent years. We aimed to explore the biological role of fibroblast growth factor 5 (FGF5) in NSCLC. We first established that the expression of FGF5 was increased in NSCLC tissues compared with the normal adjacent tissues. The expression of FGF5 was also increased in NSCLC cell lines. The effect of FGF5 silencing on cell proliferation, cell cycle, apoptosis, migration, and invasion of H661 and CALU1 cells was then examined. Downregulation of FGF5 significantly inhibited cell proliferation and induced G1 phase cell cycle arrest compared with the negative control small interfering (siNC) groups. Cell apoptosis was promoted by siFGF5 treatment. Cell migration and invasion of H661 and CALU1 cells with siFGF5 transfection were markedly diminished compared with the siNC groups. In addition, migration and invasion-associated proteins (E-cadherin, matrix metalloproteinase-2 [MMP-2], and MMP-9) and epithelial mesenchymal transition markers (N-cadherin, vimentin, snail, and slug) were also regulated by FGF5 siRNA treatment. Gene set enrichment analysis on The Cancer Genome Atlas dataset showed that the Kyoto Encyclopedia of Genes and Genomes (KEGG) cell cycle and vascular endothelial growth factor (VEGF) pathways were correlated with FGF5 expression, which was further confirmed in NSCLC cells by Western blot analysis. Our results indicated that FGF5 silencing suppressed cell growth and invasion via regulation of the cell cycle and VEGF pathways. Therefore, FGF5 may serve as a promising therapeutic strategy for NSCLC.

LncRNA PTCSC3 inhibits triple-negative breast cancer cell proliferation by downregulating lncRNA H19

Long noncoding RNA (lncRNA) PTCSC3 (hereafter PTCSC3 is used to represent lncRNA PTCSC3) inhibits glioma and thyroid cancer, indicating its potential tumor suppression function in other types of cancers. We explored the potential involvement of PTCSC3 in triple-negative breast cancer (TNBC). In the current study, we found that PTCSC3 was downregulated in tumor tissues of patients with TNBC. PTCSC3 expression was positively correlated with plasma levels of PTCSC3. LncRNA H19 was upregulated and was inversely correlated with PTCSC3 in tumor tissues. PTCSC3 overexpression led to downregulated H19 in TNBC cells, while H19 overexpression did not affect PTCSC3 expression. PTCSC3 inhibited and H19 promoted proliferation of TNBC cells. H19 overexpression attenuated the effects of PTCSC3 overexpression. Cancer cell migration and invasion were not significantly affected by PTCSC3 overexpression. Therefore, lncRNA PTCSC3 inhibits TNBC cell proliferation by downregulating lncRNA H19.

Whole transcriptome sequencing identifies crucial genes associated with colon cancer and elucidation of their possible mechanisms of action

PURPOSE

This study aimed to investigate the key long non-coding RNAs (lncRNAs) associated with colon cancer and elucidate their possible mechanisms of action.

PATIENTS AND METHODS

Eight early-stage (ES) colon tumor tissues, eight late-stage (LS) colon tumor tissues, and eight normal tissues were collected, and they were subjected to high-throughput RNA sequencing. Subsequently, comprehensive bioinformatics analyses, including the identification of differentially expressed mRNAs and lncRNAs, functional enrichment analysis, and construction of a protein-protein interaction network and an miRNA-lncRNA-mRNA regulatory network were performed. Additionally, the expression of key lncRNAs was verified using real-time quantitative PCR (qPCR).

RESULTS

In total, 549 common differentially expressed mRNAs and 30 common differentially expressed lncRNAs were identified in both the ES and LS colon cancer samples upon comparison with the normal samples. Functional enrichment analysis showed that KIAA0125 was significantly enriched in the PI3K-Akt signaling pathway and that MSTRG.35002.1 was markedly enriched in BMP signaling-related functions. Moreover, key miRNA-lncRNA-mRNA relationships, such as hsa-miR-29b-3p-KIAA0125-BCL2 and hsa-miR-29b-3p-MSTRG.35002.1-MMP2, were identified. Notably, the qPCR assay confirmed that KIAA0125 and MSTRG.35002.1 were significantly downregulated in both ES and LS colon tumor tissues compared with normal colon tissues.

CONCLUSION

Our findings indicate that key lncRNAs, including KIAA0125 and MSTRG.35002.1, may be involved in colorectal cancer (CRC) development. Downregulation of KIAA0125 may contribute to CRC development via sponging of hsa-miR-29b-3p to regulate BCL2 expression or regulating the PI3K-Akt signaling pathway. Downregulation of MSTRG.35002.1 may promote CRC development via sponging of hsa-miR-29b-3p to regulate MMP2 expression or regulating the BMP signaling pathway.

Long non‑coding RNA H19 regulates cell growth and metastasis via the miR‑22‑3p/Snail1 axis in gastric cancer

Gastric cancer (GC) is the fifth most prevalent type of malignancy and the third leading cause of cancer‑related mortality worldwide, with the prognosis of patients with late‑stage GC remaining at poor levels. Long non‑coding RNA (lncRNA) H19 (H19) is involved in the growth and metastasis of tumors, and it is upregulated under hypoxic conditions and in certain types of cancer; however, the underlying mechanisms of action of this lncRNA as regards the initiation and development of GC remain unknown. Thus, in the present study, we aimed to determine the role of lncRNA H19 in GC and to elucidate the underlying mechanisms. H19 was found to be upregulated in GC tissues and cells compared with the para‑cancerous tissues, and an elevated expression of H19 was associated with lymph node metastasis and TNM stage. Furthermore, the downregulation of H19 suppressed the proliferation, invasion, migration and epithelial‑mesenchymal transition of GC cells in vitro and suppressed tumor growth in vivo. H19 was also found to be able to bind with miR‑22‑3p, and H19‑induced cell growth and metastasis were shown to be reversed by the upregulation of miR‑22‑3p; the miR‑22‑3p level was found to inversely correlate with H19 expression in GC tissues. Furthermore, the overexpression of miR‑22‑3p notably suppressed the proliferation, migration and invasion of GC cells, and these effects were enhanced by the downregulation of Snail1. In addition, cell growth and metastasis induced by miR‑22‑3p downregulation were partially reversed by the knockdown of Snail1. Furthermore, a negative correlation was observed between the mRNA expression levels of miR‑22‑3p and Snail1 in GC tissues. On the whole, the findings of the present study revealed that H19 was upregulated in GC tissues, which promoted tumor growth and metastasis via the miR‑22‑3p/Snail1 signaling pathway. In summary, these findings provide novel insight into the potential regulatory roles of H19 in GC, and suggest that the H19/miR‑22‑3p/Snail1 axis may prove to be a promising therapeutic target for the treatment of patients with GC.

STAT3-induced upregulation of lncRNA ABHD11-AS1 promotes tumour progression in papillary thyroid carcinoma by regulating miR-1301-3p/STAT3 axis and PI3K/AKT signalling pathway

Objectives

Emerging evidences indicated the importance of long non‐coding RNAs (lncRNAs) in the tumorigenesis and deterioration of malignant tumours. To our knowledge, the study about lncRNAs in papillary thyroid carcinoma (PTC) is still inadequate. ABHD11‐AS1 was highly expressed in the PTC samples of The Cancer Genome Atlas database. This study focused on the biological function and mechanism of lncRNA ABHD11‐AS1 in PTC.

Materials and methods

qRT‐PCR analysis was used to examine the expression of ABHD11‐AS1 in PTC tissues and cell lines. The prognostic significance of ABHD11‐AS1 for the patients with PTC was analysed with Kaplan‐Meier analysis. The effects of ABHD11‐AS1 knockdown on the cell proliferation and metastasis were evaluated by in vitro functional assays and in vivo experiments. The molecular mechanism which contributed to the oncogenic role of ABHD11‐AS1 in PTC was explored by conducting mechanism experiments. Rescue assays were carried out for final demonstration.

Results

High expression of ABHD11‐AS1 predicted poor prognosis for patients with PTC and promoted cell proliferation and metastasis in vitro and in vivo. ABHD11‐AS1 was activated by the transcription factor STAT3. ABHD11‐AS1 positively regulated PI3K/AKT signalling pathway. ABHD11‐AS1 acted as a competitive endogenous (ce) RNA to upregulate STAT3 by sponging miR‐1301‐3p.

Conclusions

STAT3‐induced lncRNA ABHD11‐AS1 promoted PTC progression by regulating PI3K/AKT signalling pathway and miR‐1301‐3p/STAT3 axis.

LINC01118 Modulates Paclitaxel Resistance of Epithelial Ovarian Cancer by Regulating miR-134/ABCC1

BACKGROUND Epithelial ovarian cancer (EOC) has a high mortality rate and is a common malignant tumor of women, seriously impairing health. Chemoresistance is one of the major causes of poor prognosis. Therefore, analyzing the molecular mechanism of paclitaxel resistance has great significance. MATERIAL AND METHODS We analyzed aberrantly expressed lncRNAs in chemoresistant EOC cells by microarray and confirmed LINC01118 expression by real-time PCR. The paclitaxel sensitivity alternation was analyzed by MTS, flow cytometry, and Transwell assay, while wound healing assays were performed to assess apoptosis, migration, and invasion in vitro. The interaction between LINC01118 and miR-134 was confirmed by luciferase assay. RESULTS LINC01118 was highly expressed in EOC tissues and chemoresistant cells. Biological function experiments showed LINC01118 could facilitate paclitaxel resistance and promote migration and invasion while inhibiting apoptosis of EOC cells. Moreover, LINC01118 targets miR-134 and then affects ABCC1 expression. CONCLUSIONS LINC01118 acted as an oncogene and modulated EOC paclitaxel sensitivity by regulating miR-134/ABCC1.

H19 long non-coding RNA contributes to sphere formation and invasion through regulation of CD24 and integrin expression in pancreatic cancer cells

The long non-coding RNA H19 is highly expressed in several cancers, and the functions of H19 vary among cancer cell types. Recently, we reported that H19 contributes to the metastasis of pancreatic ductal adenocarcinoma (PDAC) cells and that inhibition of H19 reduces metastasis in vivo. However, the molecular mechanisms underlying the metastasis-promoting role of H19 in PDAC cells remain poorly elucidated. In this study, we clarified the mechanisms by which H19 regulates PDAC metastasis, with a focus on cancer stem cells (CSCs), by using H19-overexpressing and knockdown PDAC cells. Whereas the sphere-formation and invasion abilities of PDAC cells depended on H19 expression levels, other CSC characteristics of the cells, including stemness-marker expression and anticancer-drug resistance, were unaffected by H19 levels. Furthermore, metalloproteinase activity, a key mediator of invasion, was also independent of H19 expression. By contrast, H19 promoted cell adhesion through regulation of integrin and CD24 expression. Notably, the increased adhesion of H19-overexpressing cells was blocked by an anti-β1-integrin antibody, and this resulted in the inhibition of sphere formation and invasion. Thus, H19 plays critical roles in the CSC self-renewal and cell adhesion of PDAC that lead to invasion and metastasis. Our findings suggest that H19 represents a novel therapeutic target for the metastasis of pancreatic cancer.

Tumor‑released lncRNA H19 promotes gefitinib resistance via packaging into exosomes in non‑small cell lung cancer

Currently, resistance to tyrosine kinase inhibitors, such as gefitinib, has become one major obstacle for improving the clinical outcome of patients with metastatic and advanced-stage non-small cell lung cancer (NSCLC). While cell behavior can be modulated by long non-coding RNAs (lncRNAs), the contributions of lncRNAs within extracellular vesicles (exosomes) are largely unknown. To this end, the involvement and regulatory functions of lncRNA H19 wrapped by exosomes during formation of gefitinib resistance in human NSCLC were investigated. Gefitinib-resistant cell lines were built by continuously grafting HCC827 and HCC4006 cells into gefitinib-contained culture medium. RT-qPCR assays indicated that H19 was increased in gefitinib-resistant cells when compared to sensitive parent cells. Functional experiments revealed that silencing of H19 potently promoted gefitinib-induced cell cytotoxicity. H19 was secreted by packaging into exosomes and this packaging process was specifically mediated by hnRNPA2B1. H19 wrapped in exosomes could be transferred to non-resistant cells, thus inducing gefitinib resistance. Moreover, treatment-sensitive cells with exosomes highly-expressing H19 induced gefitinib resistance, while knockdown of H19 abrogated this effect. In conclusion, H19 promoted gefitinib resistance of NSCLC cells by packaging into exosomes. Therefore, exosomal H19 may be a promising therapeutic target for EGFR⁺ NSCLC patients.

Long noncoding RNA H19 participates in metformin-mediated inhibition of gastric cancer cell invasion

Recent research suggests that the first-line oral antidiabetes drug metformin may prevent gastric cancer progression and improve prognosis. Many studies have also shown that long noncoding RNAs (lncRNAs) play important roles in many biological processes. Therefore, we aimed to explore whether lncRNAs participate in the mechanisms by which metformin affects gastric cancer cells. In the current study, we found that metformin significantly inhibited the cellular functions of gastric cancer cells through Cell Counting Kit-8 and invasion assays. We found that lncRNA H19 was greatly downregulated in gastric cancer cells treated with metformin using lncRNA microassays. Based on bioinformatics analyses of the Oncomine and The Cancer Genome Atlas databases, H19 is shown to be overexpressed in gastric cancer tissues, with increased expression of H19 relating to advanced pathological tumor stage and pathological tumor node metastasis stage, indicating that H19 may be associated with the invasive ability of gastric cancer. We knocked down H19 in AGS and SGC7901 cell lines and found that knocked-down H19 could decrease gastric cancer cell invasion and that metformin could not further decrease invasion after the knock down. Moreover, H19 depletion increased AMPK activation and decreased MMP9 expression, and metformin could not further activate AMPK or decrease MMP9 in H19 knocked-down gastric cancer cells. In summary, metformin has a profound antitumor effect on gastric cancer cells, and H19 is a key component in the process of metformin suppressing gastric cancer cell invasion.