lincRNA‑p21 inhibits the progression of non‑small cell lung cancer via targeting miR‑17‑5p

LincRNA-P21 knockdown facilitates esophageal squamous cell carcinoma cell progression by upregulating cadherin 5 via YTH domain containing 1

LincRNA-P21 is a tumor suppressor in esophageal squamous cell carcinoma (ESCC). Cell adhesion modules play vital roles in cell-cell and cell-extracellular matrix (ECM) interactions and malignant cancer progression. In this study, we investigate whether lincRNA-P21 exerts its functions by regulating the cell adhesion molecule cadherin 5 (CDH5) in ESCC. Moreover, the RNA binding protein (RBP) mediators of lincRNA-P21 and CDH5 are further examined. Cell viability, growth and migratory ability are assessed by calcein-AM/PI double staining, CCK-8, EdU, Transwell, and wound healing assays. The expression of collagen I and fibronectin is examined by immunofluorescence (IF). LincRNA-P21 and CDH5 are quantified by RT-qPCR and western blot analysis. Potential lincRNA-P21 targets are identified by RNA sequencing. RBPs that can interact with lincRNA-P21 and CDH5 are identified by RNA immunoprecipitation (RIP) assay. LincRNA-P21 knockdown increases cell viability, growth, cell migration, and collagen I and fibronectin expression in ESCC cells. LincRNA-P21 depletion induces the dysregulation of 316 genes, including CDH5, in TE-1 cells. CDH5 is identified as a downstream molecule of lincRNA-P21 given its close correlation with cell adhesion, ECM reconstruction, and cancer progression. LincRNA-P21 exerts its functions by negatively regulating CDH5 expression. YTH domain containing 1 (YTHDC1) mediates the regulatory effect of lincRNA-P21 on CDH5. LincRNA-P21 knockdown elevates cell viability and growth, promotes cell migration, and induces ECM reorganization by upregulating CDH5 via RBP YTHDC1 in ESCC.

p53-regulated lncRNAs in cancers: from proliferation and metastasis to therapy

Long non-coding RNAs (lncRNAs) have been identified as master gene regulators through various mechanisms such as transcription, translation, protein modification and RNA-protein complexes. LncRNA dysregulation is frequently associated with a variety of biological functions and human diseases including cancer. The p53 network is a key tumor-suppressive mechanism that transcriptionally activates target genes to suppress cellular proliferation in human malignancies. Recent research indicates that lncRNAs play an important role in the p53 signaling pathway. In this review, we summarize the current knowledge of lncRNAs in p53-relevant functions and provide an overview of how these altered lncRNAs contribute to tumor initiation and progression. We also discuss the association between lncRNA and up- or downstream genes of p53. These findings imply that lncRNAs can help identify cellular vulnerabilities that may prove to be promising potential biomarkers and therapeutic targets for cancer treatment.

Expression Analysis of Five Different Long Non-Coding Ribonucleic Acids in Nonsmall-Cell Lung Carcinoma Tumor and Tumor-Derived Exosomes

Long non-coding ribonucleic acids (LncRNAs) are recently known for their role in regulating gene expression and the development of cancer. Controversial results indicate a correlation between the tissue expression of LncRNA and LncRNA content of extracellular vesicles. The present study aimed to evaluate the expression of different LncRNAs in non-small cell lung cancer (NSCLC) patients in tumor tissue, adjacent non-cancerous tissue (ANCT), and exosome-mediated lncRNA. Tumor and ANCT, as well as serum samples of 168 patient with NSCLC, were collected. The GHSROS, HNF1A-AS1, HOTAIR, HMlincRNA717, and LINCRNA-p21 relative expressions in tumor tissue, ANCT, and serum exosomes were evaluated in NSCLC patients. Among 168 NSCLC samples, the expressions of GHSROS (REx = 3.64, p = 0.028), HNF1A-AS1 (REx = 2.97, p = 0.041), and HOTAIR (REx = 2.9, p = 0.0389) were upregulated, and the expressions of HMlincRNA717 (REx = −4.56, p = 0.0012) and LINCRNA-p21 (REx = −5.14, p = 0.00334) were downregulated in tumor tissue in contrast to ANCT. Moreover, similar statistical differences were seen in the exosome-derived RNA of tumor tissues in contrast to ANCT samples. A panel of the five lncRNAs demonstrated that the area under the curve (AUC) for exosome and tumor was 0.937 (standard error: 0.012, p value < 0.0001). LncRNAs GHSROS, HNF1A-AS1, and HOTAIR showed high expression in tumor tissue and exosome content in NSCLC, and a panel that consisted of all five lncRNAs improved diagnosis of NSCLC.

Mechanisms Controlling MicroRNA Expression in Tumor

MicroRNAs (miRNAs) are widely present in many organisms and regulate the expression of genes in various biological processes such as cell differentiation, metabolism, and development. Numerous studies have shown that miRNAs are abnormally expressed in tumor tissues and are closely associated with tumorigenesis. MiRNA-based cancer gene therapy has consistently shown promising anti-tumor effects and is recognized as a new field in cancer treatment. So far, some clinical trials involving the treatment of malignancies have been carried out; however, studies of miRNA-based cancer gene therapy are still proceeding slowly. Therefore, furthering our understanding of the regulatory mechanisms of miRNA can bring substantial benefits to the development of miRNA-based gene therapy or other combination therapies and the clinical outcome of patients with cancer. Recent studies have revealed that the aberrant expression of miRNA in tumors is associated with promoter sequence mutation, epigenetic alteration, aberrant RNA modification, etc., showing the complexity of aberrant expression mechanisms of miRNA in tumors. In this paper, we systematically summarized the regulation mechanisms of miRNA expression in tumors, with the aim of providing assistance in the subsequent elucidation of the role of miRNA in tumorigenesis and the development of new strategies for tumor prevention and treatment.

The role of lincRNA-p21 in regulating the biology of cancer cells

Long non-coding RNAs (lncRNAs) are a type of multifunctional endogenous RNA transcript. The dysregulation of lncRNAs is considered to play a role in the initiation and progression of cancer. One such lncRNA, long intergenic non-coding RNA-p21 (lincRNA-p21), was identified in 2010 as a regulator in the p53 pathway and is gradually being identified to play crucial roles in diverse cellular processes. In this review, we have summarised the diverse regulatory functions of lincRNA-p21. For example, lincRNA-p21 has been reported to function as a protein decoy, act as a competitive endogenous RNA, regulate the transcription, regulate the translation processes and exist in the secreted exosomes. Furthermore, we highlight the emerging roles of lincRNA-p21 in cancer cell regulation. Various types of cancers, including colorectal carcinoma, hepatocellular carcinoma and non-small cell lung carcinoma, aberrantly express lincRNA-p21. However, the current understanding of the roles of lincRNA-p21 in cancer remains limited. Therefore, considering its potential as a valuable therapeutic target or biomarker for cancer, more research should be conducted to understand the role of lincRNA-p21 in cancer and other diseases.

LncRNA-p21 suppresses cell proliferation and induces apoptosis in gastric cancer by sponging miR-514b-3p and up-regulating ARHGEF9 expression

The long non-coding RNA p21 (lncRNA-p21) was a tumor suppressor gene in most cancer types including gastric cancer (GC). We aimed to identify a specific lncRNA-p21-involved pathway in regulating the proliferation and apoptosis of GC cells. A lower lncRNA-p21 expression in tumors was associated with advanced disease stage and predicted worse survival of GC patients. LncRNA-p21 overexpression in GC cell line somatic gastric cancer (SGC)-7901 and human gastric cancer (HGC)-27 suppressed cell proliferation and enhanced apoptosis, while lncRNA-p21 knockdown caused the opposite effects. Through bioinformatics analysis and luciferase-based reporter assays, we identified miR-514b-3p as a sponge target of lncRNA-p21. Cdc42 guanine nucleotide exchange factor 9 (ARHGEF9), functioned as a tumor suppress factor in GC, was found as the downstream target of miR-514-3p, and their expressions were negatively correlated in GC tumor tissues. In addition, like lncRNA-p21 overexpression alone, miR-514-3p inactivation alone also led to decreased proliferation and increased apoptosis in SGC-7901 and HGC-27 cells, which were markedly attenuated by additional ARHGEF9 knockdown. Xenograft SGC-7901 cells with more lncRNA-p21 or ARHGEF9 expressions or with less miR-514-3p expression exhibited obviously slower in vivo growth than the control SGC-7901 cells in nude mice. Our study reveals a novel lncRNA-p21/miR-514b-3p/ARHGEF9 pathway that can be targeted for GC therapy.

Oxidative Stress and Inflammation in Cardiovascular Diseases and Cancer: Role of Non-coding RNAs

High oxidative stress, Th1/Th17 immune response, M1 macrophage inflammation, and cell death are associated with cardiovascular diseases. Controlled oxidative stress, Th2/Treg anti-tumor immune response, M2 macrophage inflammation, and survival are associated with cancer. MiR-21 protects against cardiovascular diseases but may induce tumor growth by retaining the anti-inflammatory M2 macrophage and Treg phenotypes and inhibiting apoptosis. Down-regulation of let-7, miR-1, miR-9, miR-16, miR-20a, miR-22a, miR-23a, miR-24a, miR-26a, miR-29, miR-30a, miR-34a, miR-124, miR-128, miR-130a, miR-133, miR-140, miR-143-145, miR-150, miR-153, miR-181a, miR-378, and miR-383 may aid cancer cells to escape from stresses. Upregulation of miR-146 and miR-223 may reduce anti-tumor immune response together with miR-21 that also protects against apoptosis. MiR-155 and silencing of let-7e, miR-125, and miR-126 increase anti-tumor immune response. MiR expression depends on oxidative stress, cytokines, MYC, and TGF-β, and expression of silencing lncRNAs and circ-RNAs. However, one lncRNA or circ-RNA may have opposite effects by targeting several miRs. For example, PVT1 induces apoptosis by targeting miR-16a and miR-30a but inhibits apoptosis by silencing miR-17. In addition, levels of a non-coding RNA in a cell type depend not only on expression in that cell type but also on an exchange of microvesicles between cell types and tumors. Although we got more insight into the function of a growing number of individual non-coding RNAs, overall, we do not know enough how several of them interact in functional networks and how their expression changes at different stages of disease progression.

Regulation of apoptosis, autophagy and ferroptosis by non‑coding RNAs in metastatic non‑small cell lung cancer (Review)

Non-small cell lung cancer (NSCLC), a common type of cancer worldwide, is normally associated with a poor prognosis. It is difficult to treat successfully as it often metastasizes into brain or bone. Methods to facilitate the induction of effective programmed cell death (PCD) in NSCLC cells to reverse drug resistance, or to inhibit the invasion and migration of NSCLC cells, are currently under investigation. The present study summarized the regulatory functions of PCD, including apoptosis, autophagy and ferroptosis, in the context of NSCLC metastasis. It further summarized how regulatory agents, including long non-coding RNAs, circular RNAs and microRNAs, regulate PCD during the metastasis of NSCLC and characterized new potential diagnostic biomarkers of NSCLC metastasis.

ADAMTS9-AS1 Constrains Breast Cancer Cell Invasion and Proliferation via Sequestering miR-301b-3p

Objective: For determination of how ADAMTS9-AS1/miR-301b-3p/TGFBR2/JAK STAT signaling axis modulates progression of breast cancer cells.

Methods: Target lncRNA was determined by differential analysis of breast cancer expression data and survival analysis. Differentially expressed miRNAs and target mRNAs that had binding sites with target lncRNA were predicted. GSEA software was used to carry out pathway enrichment analysis for mRNAs. Binding of the researched genes were tested with RNA binding protein immunoprecipitation (RIP). How miR-301b-3p bound TGFBR2 mRNA was tested by dual-luciferase method. Transwell, colony formation, EdU approaches were employed for verification of invasion and proliferation of breast cancer cells in each treatment group.

Results: Markedly inactivated ADAMTS9-AS1 in breast cancer pertained to patient’s prognosis. MiR-301b-3p was capable of binding TGFBR2/ADAMTS9-AS1. However, overexpression of ADAMTS9-AS1 stimulated miR-301b-3p binding ADAMTS9-AS1 and repressed miR-301b-3p binding TGFBR2 mRNA. ADAMTS9-AS1 interference enhanced cancer proliferation and invasion, facilitated levels of KI67, PCNA, MMP-9 and MMP-2, and activated the JAK STAT signaling pathway. While silencing miR-301b-3p reversed the effect of ADAMTS9-AS1 interference. In addition, TGFBR2 interference or restraining JAK STAT signaling counteracted the effect of ADAMTS9-AS1.

Conclusion: ADAMTS9-AS1 could sequester miR-301b-3p to inhibit progression of breast cancer via TGFBR2/JAK STAT pathway. This study supplies a rationale for incremental apprehension of ADAMTS9-AS1 in breast cancer progression.

LncRNAs Associated with Neuronal Development and Oncogenesis Are Deregulated in SOD1-G93A Murine Model of Amyotrophic Lateral Sclerosis

Amyotrophic Lateral Sclerosis (ALS) is a devastating neurodegenerative disease caused in 10% of cases by inherited mutations considered “familial”. An ever-increasing amount of evidence is showing a fundamental role for RNA metabolism in ALS pathogenesis, and long non-coding RNAs (lncRNAs) appear to play a role in ALS development. Here, we aim to investigate the expression of a panel of lncRNAs (linc-Enc1, linc–Brn1a, linc–Brn1b, linc-p21, Hottip, Tug1, Eldrr, and Fendrr) which could be implicated in early phases of ALS. Via Real-Time PCR, we assessed their expression in a murine familial model of ALS (SOD1-G93A mouse) in brain and spinal cord areas of SOD1-G93A mice in comparison with that of B6.SJL control mice, in asymptomatic (week 8) and late-stage disease (week 18). We highlighted a specific area and pathogenetic-stage deregulation in each lncRNA, with linc-p21 being deregulated in all analyzed tissues. Moreover, we analyzed the expression of their human homologues in SH-SY5Y-SOD1-WT and SH-SY5Y-SOD1-G93A, observing a profound alteration in their expression. Interestingly, the lncRNAs expression in our ALS models often resulted opposite to that observed for the lncRNAs in cancer. These evidences suggest that lncRNAs could be novel disease-modifying agents, biomarkers, or pathways affected by ALS neurodegeneration.

LncRNA GAS5 expression in non-small cell lung cancer tissues and its correlation with Ki67 and EGFR

OBJECTIVE

This research explored and analyzed LncRNA GAS5 expression in non-small cell lung cancer (NSCLC) tissues and its correlation with Ki67 and EGFR.

METHODS

A total of 130 samples of paraffin-embedded NSCLC tissues and para-cancerous normal tissues that were collected in the Department of Pathology from January 2014 to April 2016 were selected. The relative expression of LncRNA GAS5 and Ki67/EGFR in both NSCLC tissues and para-cancerous normal tissues were detected via RT-PCR and immunohistochemistry respectively. Subsequently, we analyzed the relative expression of LncRNA GAS5, the expression of Ki67/EGFR and its correlation with clinicopathological features and prognosis of patients, and studied the correlation between LncRNA GAS5 and Ki67/EGFR.

RESULTS

The relative expression of LncRNA GAS5 in NSCLC tissues was substantially less than that of the para-cancerous normal tissues (P<0.05). The positive expression rate of Ki67/EGFR in NSCLC tissues remarkably exceeded that in para-cancerous normal tissues (P<0.05). The relative expression of LncRNA GAS5 was correlated with the degree of tumor differentiation, TNM staging and lymph node metastasis (P<0.05). The positive expression rate of Ki67 and EGFR in NSCLC tissues was related to TNM stage and metastasis of lymph node (P<0.05). In addition, the survival of patients with high LncRNA GAS5 expression was obviously superior to those with low LncRNA GAS5 expression (P<0.05), patients with negative Ki67 had superior survival than those with positive Ki67 (P<0.05), and patients with negative EGFR had increased survival over those with positive EGFR (P<0.05). Moreover, the positive rates of Ki67 and EGFR in patients with low LncRNA GAS5 expressions were obviously higher than those with high LncRNA GAS5 expressions (P<0.05). The relative expression level of LncRNA GAS5 in NSCLC patients had a remarkably negative correlation with Ki67 and EGFR (P<0.05).

CONCLUSION

The decrease in LncRNA GAS5 expression and the over-express of Ki67/EGFR occur in NSCLC tissues, the expressions of LncRNA GAS5, Ki67 and EGFR are connected with the progression, metastasis and prognosis of tumor; and LncRNA GAS5 is related to the expression of Ki67 and EGFR. These three factors are involved in the tumorigenesis and growth of the NSCLC process.

The ceRNA network of lncRNA and miRNA in lung cancer

Since lung cancer is a major causative for cancer-related deaths, the investigations for discovering biomarkers to diagnose at an early stage and to apply therapeutic strategies have been continuously conducted. Recently, long non-coding RNAs (lncRNAs) and microRNAs (miRNAs) are being exponentially studied as promising biomarkers of lung cancer. Moreover, supportive evidence provides the competing endogenous RNA (ceRNA) network between lncRNAs and miRNAs participating in lung tumorigenesis. This review introduced the oncogenic or tumor-suppressive roles of lncRNAs and miRNAs in lung cancer cells and summarized the involvement of the lncRNA/miRNA ceRNA networks in carcinogenesis and therapeutic resistance of lung cancer.

An update on long intergenic noncoding RNA p21: a regulatory molecule with various significant functions in cancer

Long intergenic noncoding RNA p21 was mapped on the human chromosome 6p21.2. Accordingly, it was firstly described by promoting the p53-dependent apoptosis in the mouse. Also, it is a new lncRNA playing some vital roles in the cell cycle, apoptosis, cell proliferation, tumorigenesis, invasion, metastasis, and angiogenesis. In this regard, it was shown that, lincRNA-p21 regulates these biological processes involved in carcinogenesis through various signaling pathways including Notch signaling, JAK2/STAT3, and AKT/mTOR pathways. Another mechanism by that lincRNA-p21 can affect these processes is a cross-talk with different miRNAs. In vitro and in vivo studies revealed dysregulation of lincRNA-p21 in various human cancers. In addition, emerging evidence demonstrated that, lincRNA-p21 can be considered as a potential prognostic and therapeutic biomarker in cancers. Also, lincRNA-p21 enhances the response to radiotherapy for colorectal cancer. However, the molecular mechanisms of lincRNA-p21 in carcinogenesis have not been fully elucidated so far. So, this review summarizes the function of lincRNA-p21, as a tumor suppressor factor in different biological processes implicated in cancers.

Data Mining and Expression Analysis of Differential lncRNA ADAMTS9-AS1 in Prostate Cancer

Long noncoding RNAs (lncRNAs) play important roles in the regulation of gene expression by acting as competing endogenous RNAs (ceRNAs). However, the roles of lncRNA-associated ceRNAs in oncogenesis are not fully understood. The present study aims to determine whether a ceRNA network can serve as a prognostic marker in human prostate cancer (PCa). In order to identify a ceRNA network and the key lncRNAs in PCa, we constructed a differentially expressed lncRNAs (DELs)-differentially expressed miRNAs (DEMis)-differentially expressed mRNAs (DEMs) regulatory network based on the ceRNA theory using data from the Cancer Genome Atlas (TCGA). We found that the DELs-DEMis-DEMs network was composed of 27 DELs nodes, seven DEMis nodes, and three DEMs nodes. The 27 DELs were further analyzed with several public databases to provide meaningful information for understanding the functional roles of lncRNAs in regulatory networks in PCa. We selected ADAMTS9-AS1 to determine its role in PCa and found that ADAMTS9-AS1 significantly influences tumor cell growth and proliferation, suggesting that it plays a tumor suppressive role. In addition, ADAMTS9-AS1 functioned as ceRNA, effectively becoming a sponge for hsa-mir-96 and modulating the expression of PRDM16. These results suggest that ceRNAs could accelerate biomarker discovery and therapeutic strategies for PCa.