Knockdown of lncRNA GHET1 suppresses cell proliferation, invasion and LATS1/YAP pathway in non small cell lung cancer

A review on the role of GHET1 in different cancers

Gastric cancer High Expressed Transcript 1 (GHET1) is an RNA gene located on chromosome 7q36.1. This non-coding RNA is involved in the pathology of different cancers. It can regulate cell proliferation, apoptosis and cell cycle transition. Moreover, it induces epithelial-mesenchymal transition. Up-regulation of GHET1 has been correlated with poor prognosis of patients with different malignancies. Besides, its up-regulation has been mostly detected in later stages and advanced grades of cancers. This review summarizes recent studies on the expression of GHET1, its in vitro functions, and its impact on the beginning and progression of cancer based on xenograft models of cancer.

Nanotechnology-empowered lung cancer therapy: From EMT role in cancer metastasis to application of nanoengineered structures for modulating growth and metastasis

Lung cancer is one of the leading causes of death in both males and females, and it is the first causes of cancer-related deaths. Chemotherapy, surgery and radiotherapy are conventional treatment of lung cancer and recently, immunotherapy has been also appeared as another therapeutic strategy for lung tumor. However, since previous treatments have not been successful in cancer therapy and improving prognosis and survival rate of lung tumor patients, new studies have focused on gene therapy and targeting underlying molecular pathways involved in lung cancer progression. Nanoparticles have been emerged in treatment of lung cancer that can mediate targeted delivery of drugs and genes. Nanoparticles protect drugs and genes against unexpected interactions in blood circulation and improve their circulation time. Nanoparticles can induce phototherapy in lung cancer ablation and mediating cell death. Nanoparticles can induce photothermal and photodynamic therapy in lung cancer. The nanostructures can impair metastasis of lung cancer and suppress EMT in improving drug sensitivity. Metastasis is one of the drawbacks observed in lung cancer that promotes migration of tumor cells and allows them to establish new colony in secondary site. EMT can occur in lung cancer and promotes tumor invasion. EMT is not certain to lung cancer and it can be observed in other human cancers, but since lung cancer has highest incidence rate, understanding EMT function in lung cancer is beneficial in improving prognosis of patients. EMT induction in lung cancer promotes tumor invasion and it can also lead to drug resistance and radio-resistance. Moreover, non-coding RNAs and pharmacological compounds can regulate EMT in lung cancer and EMT-TFs such as Twist and Slug are important modulators of lung cancer invasion that are discussed in current review.

LncRNA GHET1 and LncRNA ZXF2 as New Biomarkers in Oral Squamous Cell Carcinoma in Relation to Clinicopathological Variables

Background: The utilization of molecular techniques in detecting cancer has resulted in an improved prediction of outcomes. Oral squamous cell carcinoma (OSCC) is a prevalent illness that is frequently detected in its late stages. Therefore, finding molecular biomarkers that lead to the early detection of OSCC is of great importance. Objectives: This study aimed at evaluating the expression levels of long non-coding RNA (LncRNA) gastric carcinoma highly expressed transcript 1 (GHET1) and lncRNA ZXF2 in OSCC patients and their relationship with clinical pathology variables due to biomarker discovery and early diagnosis of OSCC. Methods: Tissue sampling was performed after selecting 30 OSCC patients and 30 healthy individuals from Emam-Khomeini Hospital, Tehran, Iran. Then, RNA extraction and cDNA synthesis were performed from these samples, using the relevant kits and their quantity and quality were measured, using nanodrop and agarose gel electrophoresis, respectively. For molecular biomarker identification and validation, real-time PCR (RT-PCR) was utilized to assess the expression of lncRNA GHET1 and lncRNA ZXF2. Data analysis was done, using GraphPad prism V.8 software. Results: The results showed that the expressions of both lncRNA GHET1 and lncRNA ZXF2 in OSCC tumor tissue increased compared to normal tissue (P < 0.0001). Receiver operating characteristic (ROC) analysis indicated that lncRNA GHET1 and lncRNA ZXF2 have the capability to be employed as biomarkers for OSCC detection. However, no significant relationship was observed between lncRNA GHET1 and lncRNA ZXF2 expressions with clinicopathological variables such as tumor stage and grade as well as patients' age. Conclusions: LncRNA GHET1 and lncRNA ZXF2 have the potential to be used as biomarkers in the early detection of OSCC and evaluating their expression in clinical settings are recommended. The use of these biomarkers in the early detection of OSCC can prevent the high mortality rate of OSCC patients. In the current study, the important role of the studied lncRNAs in OSCC diagnosis was shown. However, further studies are needed to confirm this.

lncRNA H19 facilitates the proliferation and differentiation of human dental pulp stem cells via EZH2-dependent LATS1 methylation

Human dental pulp stem cells (hDPSCs) have been recognized as a candidate cell source for tissue engineering. Long non-coding RNAs (lncRNAs) are differentially expressed in inflamed human dental pulp tissues. The present study is aimed at investigating the role of lncRNA H19 in the differentiation potential of hDPSCs. hDPSCs were successfully isolated and cultured, followed by conducting gain and loss-of-function experiments on lncRNA H19 and large tumor suppressor 1 (LATS1) to elucidate their respective biological functions in hDPSCs. lncRNA H19 was able to promote, whereas LATS1 was found to inhibit the differentiation, proliferation, and migration capabilities of hDPSCs. LATS1 was found to activate the Hippo-Yes-associated protein (YAP) signaling pathway by decreasing levels of YAP and Tafazzin (TAZ). The effects of lncRNA H19 on hDPSCs were achieved by repressing LATS1 through enhancer of zeste homolog 2-induced trimethylation of histone 3 at lysine 27. Finally, hDPSCs overexpressing lncRNA H19 and/or LATS1 were transplanted into nude mice. It was shown that lncRNA H19 inhibited LATS1 to promote the production of odontoblasts in vivo. Taken together, lncRNA H19 serves as a contributor to the differentiation potential of hDPSCs via the inhibition of LATS1, therefore highlighting novel therapeutic targets for dental pulp repair.

Long non-coding RNA GHET1 promotes thyroid cancer cell proliferation and invasion

BACKGROUND

We aimed to evaluate the role of long non-coding RNA (LncRNA) gastric carcinoma proliferation-enhancing transcript 1 (GHET1) on thyroid cancer (TC) behavior in vitro.

METHODS

TC tissues and paired adjacent normal tissues were obtained after surgical excision from 43 patients with TC. The expression of LncRNA GHET1 was analyzed by real-time (RT) PCR. Human papillary thyroid cancer cell lines (TPC-1, BCPAP) were used to examine the role of LncRNA GHET1 in vitro. Cell proliferation was determined by CCK8 and cell colony formation assays. Transwell and wound-healing assays were used to detect the invasion and migration of thyroid cancer cells.

RESULTS

Our results showed that LncRNA GHET1 was significantly more upregulated in TC tissues than in adjacent normal tissues. LncRNA GHET1 was also increased in thyroid cancer cell lines compared to normal thyroid cell lines. The upregulation of LncRNA GHET1 was significantly associated with tumor invasion, gender, and lymph node metastasis in patients with thyroid cancer. The in vitro studies showed that silencing LncRNA GHET1 in BCPAP cells inhibited cell proliferation, cell invasion, and migration. Silencing of LncRNA GHETI also promoted the cell apoptotic rate, caused an increase in the cell population at the G0/G1 phase, and decreased the cell population at the S phase. In contrast, the overexpression of LncRNA GHET1 promoted cell proliferation, invasion, and migration, inhibited cell apoptosis, and increased cell population at the S phase in TPC cells.

CONCLUSIONS

LncRNA GHET1 dysregulation might be involved in the carcinogenesis of thyroid cancer. LncRNA GHET1 could be used as a potential molecular marker and molecular target for TC.

Revisiting Lung Cancer Metastasis: Insight From the Functions of Long Non-coding RNAs

Globally, lung cancer is the most common cause of cancer-related deaths. After diagnosis at all stages, <7% of patients survive for 10 years. Thus, diagnosis at later stages and the lack of effective and personalized drugs reflect a significant need to better understand the mechanisms underpinning lung cancer progression. Metastasis should be responsible for the high lethality and recurrence rates seen in lung cancer. Metastasis depends on multiple crucial steps, including epithelial–mesenchymal transition, vascular remodeling, and colonization. Therefore, in-depth investigations of metastatic molecular mechanisms can provide valuable insights for lung cancer treatment. Recently, long noncoding RNAs (lncRNAs) have attracted considerable attention owing to their complex roles in cancer progression. In lung cancer, multiple lncRNAs have been reported to regulate metastasis. In this review, we highlight the major molecular mechanisms underlying lncRNA-mediated regulation of lung cancer metastasis, including (1) lncRNAs acting as competing endogenous RNAs, (2) lncRNAs regulating the transduction of several signal pathways, and (3) lncRNA coordination with enhancer of zeste homolog 2. Thus, lncRNAs appear to execute their functions on lung cancer metastasis by regulating angiogenesis, autophagy, aerobic glycolysis, and immune escape. However, more comprehensive studies are required to characterize these lncRNA regulatory networks in lung cancer metastasis, which can provide promising and innovative novel therapeutic strategies to combat this disease.

The significance of homeodomain transcription factor 2 in colon cancer cells

Background

Colon cancer is a serious malignant tumor. It has been reported that paired-like homeodomain transcription factor 2 (PITX2) can promote the progression of several types of cancer via regulating the Wnt/β-catenin pathway. It has also been demonstrated that high levels of long non-coding RNA (lncRNA) gastric carcinoma high expressed transcript 1 (GHET1) can also promote the development of cervical cancer via activating the Wnt/β-catenin pathway. However, whether PITX2 can affect the development of colon cancer via regulating the expression of lncRNA GHET1 remains unclear.

Results

The results demonstrated that PITX2 knockdown attenuated the proliferation, migration and invasion abilities of colon cancer cells. Additionally, PITX2 promoted the expression of lncRNA GHET1 via binding to its promoter. Overexpression of lncRNA GHET1 induced the expression of Wnt/β-catenin signaling-related proteins, cyclin D1, c-Myc and MMP-7. Furthermore, lncRNA GHET1 overexpression abrogated the PITX2 silencing-mediated decreased proliferation, migration and invasion abilities of colon cancer cells.

Conclusion

The findings of the present study suggested that PITX2 could enhance the proliferation, migration and invasion abilities of colon cancer cells via upregulating lncRNA GHET1 and activating the Wnt/β-catenin pathway.

Endothelial YAP/TAZ Signaling in Angiogenesis and Tumor Vasculature

Solid tumors are dependent on vascularization for their growth. The hypoxic, stiff, and pro-angiogenic tumor microenvironment induces angiogenesis, giving rise to an immature, proliferative, and permeable vasculature. The tumor vessels promote tumor metastasis and complicate delivery of anti-cancer therapies. In many types of tumors, YAP/TAZ activation is correlated with increased levels of angiogenesis. In addition, endothelial YAP/TAZ activation is important for the formation of new blood and lymphatic vessels during development. Oncogenic activation of YAP/TAZ in tumor cell growth and invasion has been studied in great detail, however the role of YAP/TAZ within the tumor endothelium remains insufficiently understood, which complicates therapeutic strategies aimed at targeting YAP/TAZ in cancer. Here, we overview the upstream signals from the tumor microenvironment that control endothelial YAP/TAZ activation and explore the role of their downstream targets in driving tumor angiogenesis. We further discuss the potential for anti-cancer treatments and vascular normalization strategies to improve tumor therapies.

Crosstalk of long non-coding RNAs and EMT: Searching the missing pieces of an incomplete puzzle for lung cancer therapy

BACKGROUND

Lung cancer is considered to be the first place among the cancer-related deaths worldwide and demands novel strategies in the treatment of this life-threatening disorder. The aim of this review is to explore regulation of epithelial-to-mesenchymal transition (EMT) by long non-coding RNAs (lncRNAs) in lung cancer.

INTRODUCTION

LncRNAs can be considered as potential factors for targeting in cancer therapy, since they regulate a bunch of biological processes, e.g. cell proliferation, differentiation and apoptosis. The abnormal expression of lncRNAs occurs in different cancer cells. On the other hand, epithelial-to-mesenchymal transition (EMT) is a critical mechanism participating in migration and metastasis of cancer cells.

METHOD

Different databases including Googlescholar, Pubmed and Sciencedirect were used for collecting articles using keywords such as "LncRNA", "EMT", and "Lung cancer".

RESULT

There are tumor-suppressing lncRNAs that can suppress EMT and metastasis of lung cancer cells. Expression of such lncRNAs undergoes down-regulation in lung cancer progression and restoring their expression is of importance in suppressing lung cancer migration. There are tumor-promoting lncRNAs triggering EMT in lung cancer and enhancing their migration.

CONCLUSION

LncRNAs are potential regulators of EMT in lung cancer, and targeting them, both pharmacologically and genetically, can be of importance in controlling migration of lung cancer cells.

Clinicopathological Significance of Long Non-Coding RNA GHET1 in Human Cancers: A Meta-Analysis

Introduction:

Cancer is considered as the main public health problem and the second leading cause of morbidity and mortality worldwide. Numerous environmental-lifestyle related risk factors account for around one-third of cancer deaths. Recently, the key role of lncRNAs has been widely investigated in a variety of disorders, including cancer. The lncRNA GHET1 has been considered as an essential oncogenic lncRNA in many types of human cancers. Clinical investigations indicated that expression of lncRNA GHET1 is correlated with clinicopathological characteristics in cancer. This metaanalysis investigated the correlation between the lncRNA GHET1 expression and clinicopathological features in different types of cancers.

Materials and Methods:

Comprehensive literature searches in PubMed, Scopus, and Web of Knowledge were conducted up to April 11, 2019. Sixteen studies were included in this meta-analysis. All statistical analyses were conducted using Stata software, version 12.0.

Results:

The pooled OR and 95%CIs of the sixteen relevant studies showed that over expression of lncRNA GHET1 was associated with tumor-size ≥5 cm (OR= 2.51, 95% CI: 1.89-3.33, p=0.00, I2=38.30%), positive lymph node metastasis (OR= 2.83, 95% CI: 1.78-4.52, p=0.00, I2=45.60%), advanced tumor stage (OR= 3.92, 95% CI: 2.97-5.19, p=0.00, I2=0.00%), positive distant metastasis (OR= 5.74, 95% CI: 2.58-12.77, p=0.00, I2=0.00%), advanced tumor status (OR= 2.97, 95% CI: 1.40- 6.29, p=0.01, I2=34.70%), and positive vascular invasion (OR= 2.69, 95% CI: 1.61-4.50, p=0.00, I2=29.20%).

Conclusion:

Taken together, the current study demonstrated that overexpression of lncRNA GHET1 is significantly associated with clinicopathological features in human cancers. Our results suggested that lncRNA GHET1 can be utilized as a prognostic biomarker in human cancer.

Hsa_circ_0006571 promotes spinal metastasis through sponging microRNA-138 to regulate sirtuin 1 expression in lung adenocarcinoma

Background

Circular RNAs (circRNAs) are known to participate in lung cancer. However, their role in spinal metastasis (SM) of lung adenocarcinoma remains elusive. In this study, we determined that hsa_circ_0006571 serves as a sponge for miR-138, which targets sirtuin 1 (Sirt1) in the development of SM.

Methods

A human circRNA microarray was performed to compare SM and lung adenocarcinoma samples. The expression of hsa_circ_0006571 and miR-138 was determined using quantitative polymerase chain reaction (qPCR) in vitro and in vivo. Cell proliferation was performed by Cell Counting Kit-8 (CCK-8) and apoptosis was analyzed by Annexin V/PI staining. RNA-pulldown and RNA immunoprecipitation (RIP) were used to analyze the interaction between hsa_circ_0006571. Tumor metastasis was determined through a xenograft experiment in vivo.

Results

Hsa_circ_0006571 was observed to be significantly upregulated in SM tissues through circRNA microarray and qPCR. We detected a lower expression of miR-138 in SM tissues compared with lung adenocarcinoma. Hsa_circ_0006571 silencing suppressed lung cancer cell proliferation and migration while promoting apoptosis. Hsa_circ_0006571 interacted with miR-138 to promote expression of Sirt1, leading to activation of epithelial-mesenchymal transition (EMT). Xenograft experiments showed that downregulation of hsa_circ_0006571 delayed the SM of lung adenocarcinoma cells via the miR-138-Sirt1 axis.

Conclusions

Hsa_circ_0006571 promoted tumor cell migration and invasion via the miR-138/Sirt1 pathway. Our observations indicate that circRNAs are possible novel therapeutic targets for SM of lung adenocarcinoma.

Genome-wide analysis of long non-coding RNA expression profile in lung adenocarcinoma compared to spinal metastasis

Background

Long non-coding RNAs (lncRNAs) play important roles in tumor metastasis. The aim of the present study was to investigate their expression profile and potential functions in spinal metastasis (SM) of lung adenocarcinoma.

Methods

We conducted lncRNA and mRNA expression in lung adenocarcinoma and its SM tissue using microarray analysis. Quantitative reverse-transcriptase polymerase chain reaction (qRT-PCR) revealed 10 differentially expressed lncRNAs. Gene ontology and pathway analysis were performed to test the gene effect. Possible target genes of lncRNAs were predicted based on precise algorithms.

Results

Microarray analysis found many significantly differentially expressed lncRNAs and mRNAs in lung adenocarcinoma compared with SM. qRT-PCR results aligned with those of the microarray analysis. The expression level of 10 lncRNAs showed the same trend (P<0.05). Biologic pathways known to be involved in cancer were identified among the differentially expressed mRNAs; these include cell adhesion molecules (related to 42 genes), focal adhesion (related to 31 genes), cytokine-cytokine receptor interaction (related to 48 genes), and extracellular matrix-receptor interaction (related to 23 genes). About 9,458 lncRNAs were found to have cis- or trans-genes. A total of 2,317 cis target genes were discovered to be abnormally expressed and could be regulated by lncRNAs in SM of lung adenocarcinoma.

Conclusions

Our results offer a genome-wide differential expression of lncRNA in lung adenocarcinoma and SM, as well as laying the foundation for further investigations of lncRNAs correlated with lung adenocarcinoma metastasis.

Prognostic significance of LncRNA GHET1 expression in various cancers: a systematic review and meta-analysis

BACKGROUND

Dysregulated expression of long non-coding RNA gastric carcinoma high expressed transcript 1 (lncRNA GHET1) has been observed in several cancers, however, definite conclusion on the prognostic value of lncRNA GHET1 expression in human cancers has not been determined. The aim of this meta-analysis was to evaluate the prognostic significance of lncRNA GHET1 expression in cancers.

METHODS

PubMed, Web of Science and Embase were comprehensively searched for relevant studies. Meta-analyses of overall survival (OS) and clinicopathological features were conducted.

RESULTS

Ten studies were finally analyzed in the present study. High lncRNA GHET1 expression was associated with shorter OS than low lncRNA GHET1 expression in cancers (hazard ratio (HR) = 2.59, 95% CI = 1.93-3.47, P<0.01). Online cross-validation using The Cancer Genome Atlas (TCGA) data observed similar results (HR = 1.10, P<0.05). When compared with low lncRNA GHET1 expression, high lncRNA GHET1 expression was related to larger tumor size (P<0.01), worse differentiation (P<0.01), earlier distant metastasis (P=0.02), earlier lymph node metastasis (P<0.01) and more advanced clinical stage (P<0.01).

CONCLUSION

High lncRNA GHET1 expression is associated with worse cancer prognosis and can serve as a promising prognostic factor of human cancers.

Clinicopathological and Prognostic Value of Gastric Carcinoma Highly Expressed Transcript 1 in Cancer: A Meta-Analysis

Background

Long noncoding RNA gastric cancer highly expressed transcript 1 (lncRNA GHET1) is often reported to be abnormally expressed in multiple cancers, but the situation is different in different cancers. Therefore, a meta-analysis is necessary to clarify the value of lncRNA GHET1 as a prognostic indicator in cancer.

Methods

Relevant research studies on lncRNA GHET1 and cancer were retrieved from three electronic literature databases of Web of Science, PubMed, and OVID. Meanwhile, hazard ratios (HRs) and 95% confidence intervals (CIs) were calculated to explore the relationship between lncRNA GHET1 expression and survival of cancer patients. The odds ratios (ORs) and 95% CIs were calculated to assess the association of lncRNA GHET1 expression with pathological parameters of cancer patients.

Results

The meta-analysis included a total of 11 studies involving 714 cancer patients. The pooled HR suggests that high lncRNA GHET1 expression is associated with poor overall survival. In addition, high expression of lncRNA GHET1 was found to be associated with larger tumor size, poor histological grade, high tumor stage, lymph node metastasis, and distant metastasis.

Conclusions

High lncRNA GHET1 expression can predict poor survival and pathological parameters. And lncRNA GHET1 could serve as a new indicator in multiple cancers.

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

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

Prognostic value of long non-coding RNA GHET1 in cancers: a systematic review and meta-analysis

Background

A number of studies have demonstrated the critical role of long non-coding RNA gastric cancer high expressed transcript 1 (GHET1) in many cancers. This meta-analysis provides an evidence-based evaluation of the prognostic role of GHET1 in cancer.

Materials and methods

Literature searches were conducted in several databases including Medline, Cochrane, EMBASE, CNKI, and Wanfang. The pooled odds ratio (OR) and hazard ratio (HR) with 95% confidence interval (CI) were used to evaluate the role of GHET1 in cancer. The study protocol was registered at PROSPERO (ID: CRD42018111252).

Results

Sixteen studies, containing 1315 patients, were analyzed in this meta-analysis. The pooled results indicated that GHET1 overexpression was significantly associated with poor overall survival (OS) and disease-free survival (DFS) in cancer. Moreover, up-regulation of GHET1 expression predicted larger tumor size, positive lymph node metastasis, positive distant metastasis, and advanced TNM (tumor-node-metastases) stage in human cancers.

Conclusion

There is a significant correlation between up-regulation of GHET1 and both poor prognosis and advanced clinicopathological cancer characteristics. GHET1 may be a potential prognostic predictor for human cancers.

Long non-coding RNA ANRIL enhances mitochondrial function of hepatocellular carcinoma by regulating the MiR-199a-5p/ARL2 axis

Although the roles of long non-coding RNA (lncRNA) ANRIL (Antisense non-coding RNA in the INK4A locus) have been established in various tumors, its roles in mitochondrial metabolic reprogramming of hepatocellular carcinoma (HCC) cells are still unclear. This work aims to explore lncRNA ANRIL roles in regulating the mitochondrial metabolic reprogramming of liver cancer cells. First, we found that lncRAN ANRIL expression was significantly increased in HCC tissues or cells compared with the normal adjacent tissues and normal tissues or cells. Functional experiment showed that overexpression of lncRNA ANRIL promoted mitochondrial function in HCC cells, evident by the increased mitochondrial DNA copy numbers, ATP (Adenosine triphosphate) level, mitochondrial membrane potential, and the expression levels of mitochondrial markers, while ANRIL knockdown exerted the opposite effects. Mechanistically, lncRNA ANRIL acted as a competing endogenous RNA to increase ARL2 (ADP-ribosylationfactor-like 2) expression via sponging miR-199a-5p. Notably, the miR-199a-5p/ARL2 axis is necessary for ANRIL-mediated promoting effects on HCC cell mitochondrial function. This work reveals a novel ANRIL-miR-199a-5p-ARL2 axis in HCC cell progression, which might provide potential targets for HCC treatment.

Non-coding RNA profile in lung cancer

Lung cancer is the most frequently diagnosed malignancy and the leading source of cancer-associated mortality. This kind of cancer has heterogeneous nature and is divided into two broad classes of small cell lung cancer (SCLC) and non-small cell lung cancer (NSCLC). In addition to aberrant expression of several signaling pathways and oncogenes, lung cancer is associated with dysregulation of expression of non-coding RNAs including both long non-coding RNAs (lncRNAs) and miRNAs. These aberrantly expressed transcripts are putative therapeutic targets and diagnostic/ prognostic markers. Integrative assessment of expression of lncRNAs, miRNAs and mRNAs has led to construction of competing endogenous RNA networks in which several lncRNAs act as molecular sponges to inhibit regulatory function of miRNAs on mRNAs. Notably, some of these networks seem to have subtype-specific functions in lung cancer. In this review, we summarize recent findings about the importance of these networks in the pathogenesis of lung cancer and provide a list of onco-miRNAs, tumor suppressor miRNAs, oncogenic lncRNAs and tumor suppressor lncRNAs based on their roles in the carcinogenic process in lung cancer.

Long non-coding RNAs: How to regulate the metastasis of non-small-cell lung cancer

Non–small‐cell lung cancer (NSCLC) has become the most lethal human cancer because of the high rate of metastasis. Hence, clarifying the molecular mechanism underlying NSCLC metastasis is very important to improve the prognosis of patients with NSCLC. Long non‐coding RNAs (LncRNAs) are a class of RNA molecules longer than 200 nucleotides, which can participate in diverse biological processes. About 18% of human LncRNAs were recently found to be associated with tumours. Many studies indicated that aberrant expression of LncRNAs played key roles in the progression and metastasis of NSCLC. According to the function in tumours, LncRNAs can be divided into two classes: oncogenic LncRNAs and tumour‐suppressor LncRNAs. In this review, we summarized the main molecular mechanism of LncRNAs regulating NSCLC metastasis, including three aspects: (a) LncRNAs interact with miRNAs as ceRNAs; (b) LncRNAs bind with target proteins; and (c) LncRNAs participate in the transduction of different signal pathways. Then, LncRNAs can exert their function to regulate the metastasis of NSCLC through influencing the progression of epithelial‐mesenchymal transition (EMT) and the properties of cancer stem cell (CSC). But, it is necessary to do some further research to demonstrate the LncRNAs particular regulatory mechanism of inhibiting the metastasis of NSCLC and explore new drugs targeting LncRNAs.

Long non-coding RNA TNRC6C-AS1 promotes methylation of STK4 to inhibit thyroid carcinoma cell apoptosis and autophagy via Hippo signalling pathway

The role of long non-coding RNAs (lncRNAs) in thyroid carcinoma (TC), the most frequent endocrine malignancy, has been extensively examined. This study investigated effect of interaction among lncRNA TNRC6C-AS1, serine/threonine-protein kinase 4 (STK4) and Hippo signalling pathway on TC. Initially, lncRNA TNRC6C-AS1 expression in TC tissues was detected. To explore roles of lncRNA TNRC6C-AS1, STK4 and Hippo signalling pathway in TC progression, their expressions were altered. Interaction between lncRNA TNRC6C-AS1 and STK4, STK4 promoter methylation, or Hippo signalling pathway was verified. After that, a series of experiments were employed to evaluate in vitro ability of apoptosis, proliferation and autophagy of TC cells and in vivo tumorigenicity, and tumour growth of TC cells. lncRNA TNRC6C-AS1 was highly expressed while STK4 was poorly expressed in TC tissues. LncRNA TNRC6C-AS1 promoted the STK4 methylation and down-regulated STK4 expression, which further activated the Hippo signalling pathway. STK4 silencing was observed to promote the proliferation ability of TC cells, inhibit the apoptosis and autophagy abilities, as well as enhance the tumorigenicity and tumour growth. Moreover, the in vitro proliferation ability as well as the in vivo tumorigenicity and tumour growth of TC cells were inhibited after the blockade of Hippo signalling pathway, while the apoptosis and autophagy abilities were promoted. The results demonstrate that the lncRNA TNRC6C-AS1 increases STK4 promoter methylation to down-regulate STK4 expression, thereby promoting the development of TC through activation of Hippo signalling pathway. It highlights that lncRNA TNRC6C-AS1 may be a novel therapeutic target for the treatment of TC.

The Value of lncRNA GHET1 as a Prognostic Factor for Survival of Chinese Cancer Outcome: A Meta-Analysis

Aim

There is increasing evidence that high expression levels of the gastric carcinoma highly expressed transcript 1 (GHET1), a long noncoding RNA (lncRNA), are associated with cancer prognosis and may be used as a valuable biomarker for cancer patients. The purpose of this meta-analysis was to analyze existing data to reveal potential clinical applications of GHET1 for cancer prognosis and tumor progression. All of these studies included in this meta-analysis were collected through a variety of retrieval strategies; and the enrolled articles were qualified via the meta-analysis of enrolled studies in epidemiology (MOOSE) and the preferred reporting items for systematic reviews and meta-analyses (PRISMA) checklists.

Materials and Methods

The literature collection was performed by a comprehensive search through electronic databases for studies published on or before March 10, 2019. These included the Cochrane library, PubMed, Embase, Web of Science, Springer, Science Direct, and three Chinese databases: CNKI, Weipu, and Wanfang. Seven studies that met the specified criteria were analyzed in the present research.

Results

The combined results indicate that an elevated GHET1 expression level is significantly associated with poor overall survival (OS) (HR = 2.40, 95% CI: 1.87–3.08, p < 0.001) and tumor progression (III/IV vs. I/II: HR = 1.80, 95% CI: 1.48–2.18, p < 0.001) in multiple cancers. The elevated GHET1 expression was also associated with lymph node metastasis (LNM) (HR = 2.44, 95% CI: 1.86–3.20, p < 0.001) in Chinese cancer patients. Conclusions. The present findings indicate that an increased GHET1 expression level is associated with poor OS, tumor progression, and LNM in patients with multiple tumors and may serve as a useful prognostic biomarker in Chinese cancer patients.

Long noncoding RNA MALAT1 promotes the stemness of esophageal squamous cell carcinoma by enhancing YAP transcriptional activity

The tumor promoting roles of long noncoding RNA (lncRNA) MALAT1 have been revealed in various cancers; however, its roles in esophageal squamous cell carcinoma (ESCC) have not previously been disclosed. In this study, we found that MALAT1 expression was remarkably increased in ESCC cells compared to normal human esophageal epithelial cells. In addition, knockdown of MALAT1 attenuated the stemness of ESCC cells, as evidenced by a decrease in spheroid formation capacity, stemness marker expression and aldehyde dehydrogenase 1 activity. Moreover, MALAT1 knockdown decreased the migration ability of ESCC cells. Notably, knockdown of MALAT1 enhanced the radiosensitivity and chemosensitivity of ESCC cells. We also established that MALAT1 binds directly to Yes-associated protein (YAP), thereby enhancing YAP protein expression and increasing YAP transcriptional activity. Overexpression of YAP partially rescued the effect of MALAT1 knockdown on stemness and radiosensitivity of ESCC cells. Overall, this study has identified that a novel MALAT1-YAP axis promotes the stemness of ESCC cells, and thus could be a potential target for treatment of ESCC.

LncRNA MALAT1 increases the stemness of gastric cancer cells via enhancing SOX2 mRNA stability

Gastric cancer is one of the most common malignancies globally; cancer stem cells (CSCs) are regarded as being at the root of tumor progression, and there is thus a need to identify potential drugs to target CSCs. The long non-coding RNA MALAT1 promotes epithelial-mesenchymal transition and angiogenesis in colorectal cancer, but it is unknown whether it affects the stemness of gastric cancer cells. Here, we found that knockdown (KD) of MALAT1 attenuated the stemness of non-adherent gastric cancer cell spheroids, as evidenced by a decrease in primary and secondary spheroid formation capacity and expression of stemness markers. In contrast, overexpression (OE) of MALAT1 enhanced the stemness of adherent gastric cancer cells. Notably, KD of MALAT1 enhanced radiosensitivity and chemosensitivity of gastric cancer cell spheroids. We report that MALAT1 directly binds to sox2 mRNA (which encodes a critical master pluripotency factor), enhances the mRNA stability and increases its expression; KD of sox2 partially reversed the effect of MALAT1 OE on the stemness of gastric cancer cells. Importantly, expression of MALAT1 and sox2 exhibited a positive correlation in clinical samples. Therefore, our results indicate the existence of a novel MALAT1-sox2 axis which promotes the stemness of gastric cancer cells and may be a potential target for gastric cancer.

Overexpression of LncRNA GHET1 predicts an unfavourable survival and clinical parameters of patients in various cancers

Recently, increasing studies have reported that long non‐coding RNA (lncRNA) gastric carcinoma highly expressed transcript 1 (GHET1) is highly expressed in variety of cancers and relevant to poor prognosis of cancer patients. Nevertheless, the results were inconsistent and the systematic analysis of lncRNA GHET1 in cancers has not been inspected. Thus, we aim to evaluate the relationship between lncRNA GHET1 expression and clinical outcomes in human cancers. We searched keywords in PubMed, Web of Science, Embase, Cochrane Library and ClinicalTrial.gov. Stata SE12.0 software was used in the quantitative meta‐analysis. Pooled hazard ratio (HR) and odds ratio with 95% confidence interval (95% Cl) were calculated to evaluate the clinical significance of lncRNA GHET1. Twelve studies totalling 761 patients with cancers were included for analysis. The pooled results of this study indicated that high lncRNA GHET1 expression level was significantly associated with poor overall survival (OS, HR = 2.30, 95% CI: 1.75‐3.02) in human cancers. The statistical significance was also detected in subgroup analysis stratified by analysis method, cancer type, sample size and follow‐up time respectively. In addition, the elevated lncRNA GHET1 expression was also significantly related to more advanced clinical stage, earlier lymph node metastasis, earlier distant metastasis and bigger tumour size. LncRNA GHET1 may serve as a promising biomarker for prognosis in Asians with cancers.

Prognostic value of long noncoding RNA ROR in patients with cancer in China: A systematic review and meta-analysis

BACKGROUND

For cancer, it is common that there is usually a dysregulation of the long noncoding RNA regulator of reprogramming (LncRNA ROR). To illustrate the application of LncRNA ROR, which serves as the prognostic marker for the malignant tumors, it is of great importance to conduct a meta-analysis.

METHODS

There were 3 databases being applied. The data used were collected before January 5, 2018. These 3 databases include the OVID, PubMed, and Science databse. To further explore the association between the expression and survival of LncRNA ROR, it calculated the 95% confidence intervals (CIs) and hazard ratios (HRs). Meanwhile, the odds ratios (ORs) have been calculated for the evaluation of the correlation between the pathological and expression parameters of LncRNA ROR.

RESULTS

There were 8 researches participated by 720 patients. According to the HR, it has been implied that there was a high LncRNA ROR expression related with the weak disease-free survival (DFS) (HR = 3.48, 95% CI, 2.24-5.41) and overall survival (OS) (HR = 2.47, 95% CI, 1.76-3.47) among the cancer patients with none dramatic heterogeneity. There was also a correlation among lymph node metastasis (OR = 5.38, 95% CI, 2.21-13.12), high tumor stage (OR = 3.80, 95% CI, 1.95-7.41), and larger tumor size (OR = 4.43, 95% CI, 1.26-15.51).

CONCLUSIONS

Thus, it can be predicted about the lymph node metastasis and high tumor stage, larger tumor size, DFS, and poor OS based on the high LncRNA ROR. This suggests that high LncRNA ROR can be used as a new indicator of poor prognosis in cancer.

Knockdown of LncRNA GHET1 suppresses prostate cancer cell proliferation by inhibiting HIF-1α/Notch-1 signaling pathway via KLF2

Prostate cancer (PC) is one of the most common cancers in male groups worldwide. Long noncoding RNAs (LncRNAs) are reported to be dysregulated in a variety of cancers, including PC. This study aimed to explore the role of LncRNA GHET1 in the pathogenesis of PC. RT-qPCR was carried out to examine the relative expression level of GHET1 in PC patients. In vitro, GHET1 siRNA (si-GHET1) was used to investigate the biological role of GHET1 in PC cell lines. Cell proliferation was detected by CCK-8 and colony formation assay, while cell cycle and cell apoptosis were analyzed using flow cytometry. Moreover, western blot was carried out to measure the protein expression levels of KLF2 and HIF-1α/Notch-1 signal pathway. We found that GHET1 showed higher expression in PC tissues and had a negative correlation with KLF2 expression. Knockdown of GHET1 significantly suppressed the cell proliferation, induced cell cycle arrest at G0/G1 phase and promoted cell apoptosis. Additionally, si-GHET1 transfection induced KLF2 upregulation and HIF-1α/Notch-1 signal pathway suppression, which could be rescued by si-KLF2 transfection. These results suggest the key role of GHET1 in PC progression. Moreover, GHET1 might be explored to be a potential target for clinical treatment of PC. © 2019 BioFactors, 45(3):364-373, 2019.

GHET1 acts as a prognostic indicator and functions as an oncogenic lncRNA in cervical cancer

Gastric carcinoma proliferation enhancing transcript 1 (GHET1) has been suggested to serve as a promising oncogenic lncRNA in various types of human cancer. However, the role of GHET1 remained unknown in cervical cancer. In our study, we found GHET1 expression was markedly elevated in cervical cancer tissue specimens and cell lines compared with adjacent normal cervical tissue specimens and human normal cervical cell line, respectively. Then, we found high expression of GHET1 is a useful biomarker to discriminate cervical cancer tissues from non-tumorous tissues, and associated with advanced clinical stage, lymph node metastasis, distant metastasis and poor histological grade in cervical cancer patients. The survival analysis showed high GHET1 expression was an independent unfavorable prognostic factor in cervical cancer patients. Knockdown of GHET1 expression markedly inhibits cervical cancer cell proliferation, migration, and invasion. The loss-of-function study indicated knockdown of GHET1 expression markedly inhibits cervical cancer cell proliferation, migration, and invasion. In conclusion, GHET1 acts as an oncogenic lncRNA in cervical cancer.

Knockdown of lncRNA GHET1 inhibits osteosarcoma cells proliferation, invasion, migration and EMT in vitro and in vivo

OBJECTIVE

Osteosarcoma is the most common primary malignant skeleton tumor that derives from mesenchymal cells. Emerging evidences have identified the vital role of long non-coding RNAs (lncRNAs) in the development of osteosarcoma. In this study, we aimed to investigate the role of lncRNA gastric carcinoma highly expressed transcript 1 (GHET1) in osteosarcoma progression.

METHODS

The expression levels of relevant genes in clinical samples and cell lines were determined by quantitative real-time PCR. Cell proliferation was determined by CCK8 and cell colony formation assays. Transwell assay was used to detect the invasion and migration of osteosarcoma cells. Cell apoptosis and cell cycle were detected by flow cytometry. Protein levels were detected by western blot. In vivo tumor growth was investigated in the xenograft nude mice model. To determine whether growth inhibition and apoptosis are responsible for antitumor activity of silencing GHET1, immunohistochemistry for proliferation and TUNEL assay was performed in xenograft tissues. In vivo lung metastasis was performed to detect the effect of GHET1 on cell metastasis ability.

RESULTS

Our results revealed that GHET1 was up-regulated in osteosarcoma tissues compared to normal tissues. GHET1 was also increased in osteosarcoma cell lines compared to normal osteoplastic cell line. The up-regulation of GHET1 was significantly associated with TNM stage, distant metastasis and lymph node metastasis in patients with osteosarcoma. In vitro studies showed that silencing GHET1 in MG-63 and U2OS cells inhibited cell proliferation, cell invasion and migration and epithelial-to-mesenchymal transition (EMT), promoted cell apoptotic rate, and also caused an increase in cell population at G0/G1 phase with a decrease in cell population at S phase. Overexpression of GHET1 promoted the proliferation, invasion and migration of osteosarcoma cells. Importantly, silencing GHET1 inhibited tumor growth and tumor metastasis in mice MG-63-xenograft model in association with changes of EMT-related genes, reduced expression of Ki-67 and promotion of apoptosis.

CONCLUSION

GHET1 was up-regulated in osteosarcoma tissues and cell lines, inhibited cell apoptosis, promoted cell proliferation, invasion and migration by affecting EMT in vitro, and was correlated with the tumor growth and metastasis in vivo. GHET1 may be a potential therapeutic target of osteosarcoma treatment.

Silencing of the long non-coding RNA GHET1 inhibits cell proliferation and migration of renal cell carcinoma through epithelial-mesenchymal transition

Long non-coding RNAs (lncRNAs) have been demonstrated to serve vital roles in renal cell carcinoma (RCC) development. Gastric carcinoma high expressed transcript 1 (GHET1) regulates numerous biological processes in cancer cells. However, the biological role of GHET1 in RCC has not yet been identified. This study aimed to investigate the role of GHET1 in RCC. In the present study, the expression of GHET1 in RCC tissues and the 786-O, A498 and 293 cell lines was assessed by reverse transcription-quantitative polymerase chain reaction. Cell Counting Kit-8, colony formation and cell scratch assays were used to determine the effects of GHET1 on tumorigenesis. Western blotting was performed to examine the effect of GHET1 on epithelial-mesenchymal transition (EMT) in RCC cells. GHET1 expression was significantly increased in the RCC samples in comparison with adjacent tissues. High expression levels of GHET1 were associated with distant metastasis and clinical stage severity, thus, high GHET1 expression may serve as a predictor for a poor prognosis. In addition, RCC cells presented higher GHET1 mRNA and protein expression levels compared with in 293 cells. Furthermore, silencing GHET1 suppressed cell growth, weakened cell migration and inhibited EMT of RCC cells in vitro. In conclusion, the present study suggested that GHET1 may be considered a therapeutic target for the treatment or prevention of RCC.

Long noncoding RNA GHET1 in human cancer

LncRNAs are a group of noncoding RNAs that are >200 nucleotides in length. These RNAs have no significant protein-coding potential due to the lack of obvious open reading frames. To date, accumulating evidence has demonstrated that dysregulation of lncRNAs exhibits indispensable roles in the pathological processes of human cancers. These RNAs function as either oncogenes or tumor suppressor genes to regulate proliferation, migration and invasion of cancer cells. GHET1, a prominent oncogenic lncRNA, is highly expressed in diverse malignancies. Furthermore, GHET1 performs key functions in carcinogenesis and progression, suggesting that GHET1 is expected to be a prospective biomarker or therapeutic target for cancers. In this review, we provide a summary of the current evidence concerning the biological functions, underlying mechanisms and clinical significance of GHET1 during tumor development.

Long noncoding RNA LINC00961 inhibits cell proliferation and induces cell apoptosis in human non-small cell lung cancer

Long noncoding RNAs (LncRNAs) have been identified in multiple human cancer types, including lung cancer. An increasing number of studies have indicated that lncRNAs can function as important gene regulators. However, the biological mechanism of LINC00961 in lung cancerremains poorly understood. In our current study, we recognized lncRNA LINC00961, and we observed that it was significantly reduced in human non-small cell lung cancer (NSCLC) tissues. LINC00961 was elevated by infecting LV-LINC00961, while decreased by LV-shLINC00961 in H226 and A549 cells. Furthermore, it was shown that LINC00961 overexpression greatly inhibited lung cancer cell proliferation, whereas downregulated LINC00961 induced cell proliferation. In addition, further experiments showed that restoration of LINC00961 could dramatically increase apoptotic ratios of NSCLC H226 and A549 cells, and knockdown of LINC00961 exhibited an opposite effect. Moreover, Western blot analysis showed that upregulation of LINC00961 repressed proliferating cell nuclear antigen expression and increased Bax expression, indicating that it acts as an important pro-apoptosis gene. Conversely, inhibition of LINC00961 induced proliferating cell nuclear antigen expression and restrained Bax protein levels. Taking these together, LINC00961 might play a tumor suppressive role in NSCLC progression, and it could serve as a novel prognostic biomarker in NSCLC diagnosis and treatment.