Noncoding RNA Expression Aberration Is Associated with Cancer Progression and Is a Potential Biomarker in Esophageal Squamous Cell Carcinoma. Int J Mol Sci. 2015;16:27824-27834. [PMID: 26610479 DOI: 10.3390/ijms161126060]

Expression and significant roles of the long non-coding RNA CASC19/miR-491-5p/HMGA2 axis in the development of gastric cancer

BACKGROUND

Gastric cancer (GC) is a common malignant tumor, long non-coding RNA and microRNA (miRNA) are important regulators that affect tumor proliferation, metastasis and chemotherapy resistance, and thus participate in tumor progression. CASC19 is a new bio-marker which can promote tumor invasion and metastasis. However, the mechanism by which CASC19 affects the progression of GC through miRNA is not clear.

AIM

To explore the role of the CASC19/miR-491-5p/HMGA2 regulatory axis in GC.

METHODS

To explore the expression and prognosis of CASC19 in GC through clinical samples, and investigate the effects of inhibiting CASC19 on the proliferation, migration, invasion and other functions of GC cells through cell counting Kit-8 (CCK-8), ethynyldeoxyuridine, Wound healing assay, Transwell, Western blot and flow cytometry experiments. The effect of miR-491-5p and HMGA2 in GC were also proved. The regulatory relationship between CASC19 and miR-491-5p, miR-491-5p and HMGA2 were validated through Dual-luciferase reporter gene assay and reverse transcription PCR. Then CCK-8, Transwell, Wound healing assay, flow cytometry and animal experiments verify the role of CASC19/miR-491-5p/HMGA2 regulatory axis.

RESULTS

The expression level of CASC19 is related to the T stage, N stage, and tumor size of patients. Knockdown of the expression of CASC19 can inhibit the ability of proliferation, migration, invasion and EMT conversion of GC cells, and knocking down the expression of CASC19 can promote the apoptosis of GC cells. Increasing the expression of miR-491-5p can inhibit the proliferation of GC cells, miR-491-5p mimics can inhibit EMT conversion, and promote the apoptosis of GC cells, while decreasing the expression of miR-491-5p can promote the proliferation and EMT conversion and inhibit the apoptosis of GC cells. The expression of HMGA2 in GC tissues is higher than that in adjacent tissues. At the same time, the expression level of HMGA2 is related to the N and T stages of the patients. Reducing the level of HMGA2 can promote cell apoptosis and inhibit the proliferation of GC cells. Cell experiments and animal experiments have proved that CASC19 can regulates the expression of HMGA2 through miR-491-5p, thereby affecting the biological functions of GC.

CONCLUSION

CASC19 regulates the expression of HMGA2 through miR-491-5p to affect the development of GC. This axis may serve as a potential biomarker and therapeutic target of GC.

Exosomal miR-196a-5p contributes to esophageal squamous cell carcinoma malignant progression by inhibiting ITM2B

Exosomes from cancer cells function as carriers to spread or transport specific microRNAs (miRNAs) to distant sites to exert their effects, but the mechanism of exosomal miRNA action in esophageal squamous cell carcinoma (ESCC) has not been fully explained. Therefore, in this study, we were interested in the impact of exosomal miR-196a-5p in ESCC progression. We found that miR-196a-5p was expressed enriched in clinical tissues, ESCC cells, and exosomes. Functionally, depletion of miR-196a-5p impeded ESCC cell growth, migration, and invasion, whereas overexpression of miR-196a-5p produced the opposite results. Moreover, enhancement of exosomal miR-196a-5p in recipient ESCC cells triggered more intense proliferation and migration. Mechanistically, we identified integral membrane protein 2B (ITM2B) as a direct target of miR-196a-5p. Silencing of ITM2B partially counteracted the inhibitory effect of miR-196a-5p inhibitors on the malignant phenotype of ESCC. Furthermore, in vivo, lower miR-196a-5p levels triggered by the introduction of antagomiR-196a-5p resulted in the generation of smaller volume and weight xenograft tumors. Thus, our results demonstrated novel mechanisms of exosomal and intracellular miR-196a-5p-mediated ESCC growth and migration and identify the interaction of miR-196a-5p with ITM2B. These works might provide new targets and basis for the development of clinical treatment options for ESCC.

Non‑coding RNA: A promising diagnostic biomarker and therapeutic target for esophageal squamous cell carcinoma (Review)

Esophageal cancer (EC) is a common form of malignant tumor in the digestive system that is classified into two types: Esophageal squamous cell carcinomas (ESCC) and esophageal adenocarcinoma. ESCC is known for its early onset of symptoms, which can be difficult to identify, as well as its rapid progression and tendency to develop drug resistance to chemotherapy and radiotherapy. These factors contribute to the high incidence of disease and low cure rate. Therefore, a diagnostic biomarker and therapeutic target need to be identified for ESCC. Non-coding RNAs (ncRNAs) are a class of molecules that are transcribed from DNA but do not encode proteins. Initially, ncRNAs were considered to be non-functional segments generated during transcription. However, with advancements in high-throughput sequencing technologies in recent years, ncRNAs have been associated with poor prognosis, drug resistance and progression of ESCC. The present study provides a comprehensive overview of the biogenesis, characteristics and functions of ncRNAs, particularly focusing on microRNA, long ncRNAs and circular RNAs. Furthermore, the ncRNAs that could potentially be used as diagnostic biomarkers and therapeutic targets for ESCC are summarized to highlight their application value and prospects in ESCC.

Role of non-coding RNAs mediated pyroptosis on cancer therapy: a review

INTRODUCTION

Non-coding RNAs (ncRNAs), which are incapable of encoding proteins, are involved in the progression of numerous tumors by altering transcriptional and post-transcriptional processing. Recent studies have revealed prominent features of ncRNAs in pyroptosis, a type of non-apoptotic programmed cellular destruction linked to an inflammatory reaction. Drug resistance has arisen gradually as a result of anti-apoptotic proteins, therefore strategies based on pyroptotic cell death have attracted increasing attention. We have observed that ncRNAs may exert significant influence on cancer therapy, chemotherapy, radio- therapy, targeted therapy and immunotherapy, by regulating pyroptosis.

AREAS COVERED

Literatures were searched (December 2023) for studies on cancer therapy for ncRNAs-mediated pyroptotic cell death.

EXPERT OPINION

The most universal mechanical strategy for ncRNAs to regulate target genes is competitive endogenous RNAs (ceRNA). Besides, certain ncRNAs could directly interact with proteins and modulate downstream genes to induce pyroptosis, resulting in tumor growth or inhibition. In this review, we aim to display that ncRNAs, predominantly long non-coding RNAs (lncRNAs), microRNAs (miRNAs) and circular RNAs (circRNAs), could function as potential biomarkers for diagnosis and prognosis and produce new insights into anti-cancer strategies modulated by pyroptosis for clinical applications.

Research Progress on the Predicting Factors and Coping Strategies for Postoperative Recurrence of Esophageal Cancer

Esophageal cancer is one of the malignant tumors with poor prognosis in China. Currently, the treatment of esophageal cancer is still based on surgery, especially in early and mid-stage patients, to achieve the goal of radical cure. However, esophageal cancer is a kind of tumor with a high risk of recurrence and metastasis, and locoregional recurrence and distant metastasis are the leading causes of death after surgery. Although multimodal comprehensive treatment has advanced in recent years, the prediction, prevention and treatment of postoperative recurrence and metastasis of esophageal cancer are still unsatisfactory. How to reduce recurrence and metastasis in patients after surgery remains an urgent problem to be solved. Given the clinical demand for early detection of postoperative recurrence of esophageal cancer, clinical and basic research aiming to meet this demand has been a hot topic, and progress has been observed in recent years. Therefore, this article reviews the research progress on the factors that influence and predict postoperative recurrence of esophageal cancer, hoping to provide new research directions and treatment strategies for clinical practice.

LncRNA SNHG3 promoted cell proliferation, migration, and metastasis of esophageal squamous cell carcinoma via regulating miR-151a-3p/PFN2 axis

Esophageal squamous cell carcinoma (ESCC) is an aggressive malignant tumor with a poor prognosis. The dysregulation of long non-coding RNAs (lncRNAs) is closely related to the tumorigenesis and progression of ESCC. However, the effects of lncRNA small nucleolar RNA host gene 3 (lncRNA SNHG3) in ESCC are still unclear. Therefore, a series of experiments methods, such as quantitative real-time polymerase chain reaction, function gain/loss experiments, western blots, and animal xenograft tumor model, were employed to explore the biological function and molecular mechanism of SNHG3 in ESCC. As results, we first reported that SNHG3 was significantly up-regulated in ESCC tissues and cells. SNHG3 knockdown obviously inhibited cell proliferation, migration, invasion, and promoted apoptosis. Mechanism analysis revealed that SNHG3 sponged miR-151a-3p to regulate PFN2. Inhibition of miR-151a-3p and overexpression of PFN2 attenuated the positive effect of SNHG3 knockdown on suppressing tumor progression. Furthermore, the anti-tumor effects of SNHG3 knockdown were also observed in vivo. In summary, our results indicated that SNHG3 knockdown suppressed tumor development via the miR-151a-3p/PFN2 axis, and targeting SNHG3 may provide a new opportunity for ESCC patients.

Long non-coding RNA NRSN2-AS1, transcribed by SOX2, promotes progression of esophageal squamous cell carcinoma by regulating the ubiquitin-degradation of PGK1

Aberrant expression of long non-coding RNAs (lncRNAs) plays pivotal roles in tumorigenesis of human malignant cancers, including esophageal squamous cell carcinoma (ESCC). However, the specific role of lncRNA NRSN2-AS1 in ESCC has not been investigated. Our analysis of clinical data revealed that NRSN2-AS1 was upregulated in ESCC tissues and negatively correlated with patient survival. Luciferase reporter assays and chromatin immunoprecipitation assays demonstrated that NRSN2-AS1 is transcribed by SOX2. In vitro functional experiments showed that NRSN2-AS1 can promote ESCC cell proliferation, migration, and invasion. Furthermore, NRSN2-AS1-binding proteins were detected using RNA pull-down assays and mass spectrometry. Mechanistically, NRSN2-AS1 can bind to phosphoglycerate kinase 1 (PGK1) and upregulate its protein levels by inhibiting its ubiquitination. Knockdown of PGK1 in part abolished the NRSN2-AS1 overexpression-induced effects on ESCC cell proliferation, migration, invasion, and epithelial‑mesenchymal transition (EMT). Thus, NRSN2-AS1 may be a diagnostic biomarker or treatment target for ESCC.

ING5 Inhibits Migration and Invasion of Esophageal Cancer Cells by Downregulating the IL-6/CXCL12 Signaling Pathway

Esophageal squamous cell carcinoma (ESCC) is a common cancer in East Asia and in other parts of the world and exhibits a poor prognosis. Growth inhibitor 5 (ING5) is a new member of the growth inhibitor (ING) protein family and is involved in many important cellular functions, such as the cell cycle, apoptosis, and chromatin remodeling. As a newly discovered tumor suppressor, ING5 has been shown to inhibit lung cancer proliferation and distant metastasis through the AKT pathway. In lung cancer tumors, ING5 can attenuate the ability of cancer cells to invade normal tumor-adjacent tissues. However, ING5 has rarely been studied in ESCC. Here, we found that in ESCC EC-109 cancer cells, ING5 overexpression inhibited cell proliferation and tumor invasion, whereas, in ESCC TE-1 cancer cells, ING5 knockdown promoted cell invasion. In a nude mouse xenograft model, ING5 overexpression inhibited tumor growth and the invasion ability of ESCC cells. Further studies revealed that ING5 overexpression inhibited IL-6/CXCL12 expression at both the mRNA and protein levels as well as morphological changes. We found for the first time that ING5 inhibits ESCC cell migration and invasion by downregulating the IL-6/CXCL12 signaling pathway.

LINC00239 Interacts with C-Myc Promoter-Binding Protein-1 (MBP-1) to Promote Expression of C-Myc in Esophageal Squamous Cell Carcinoma

Increasing evidence demonstrates that long non-coding RNAs (lncRNA) play a vital role in the progression of tumors, containing esophageal squamous cell carcinoma (ESCC). LINC00239 was reported as an oncogene in diverse kinds of cancers, whereas its specific role is still unclear in ESCC. In this study, we detected the expression and functional role of LINC00239 in ESCC specimens and cells, and investigated the molecular mechanisms of it. LINC00239 was highly expressed in ESCC tissues and cells, and was related to poor prognosis of patients with ESCC. The proliferation, metastasis, and invasion ability as well as epithelial-mesenchymal transition (EMT) process were all enhanced in LINC00239-overexpressed ESCC cells. LINC00239 was upregulated in TGF-β1-treated ESCC cells. Furthermore, LINC00239 was found to bind directly to the transcription factor c-Myc promoter-binding protein-1 (MBP-1). MBP-1 was detected to inhibit the transcription of c-Myc in ESCC. Moreover, LINC00239 could activate c-Myc transcription through influencing MBP-1-binding ability to c-Myc promoter. These data suggest that LINC00239 may act as an oncogene to promote the transcription of c-Myc by competitively combining with MBP-1 in ESCC, and may serve as a potential target for antitumor therapy in ESCC. IMPLICATIONS: LINC00239 may function as an oncogenic lncRNA in ESCC through the LINC00239/MBP-1/c-Myc axis to activate EMT process.

Screening of tumor grade-related mRNAs and lncRNAs for Esophagus Squamous Cell Carcinoma

Background

The goal of our study was to screen tumor grade‐related lncRNAs and mRNAs to reveal the underlying molecular mechanism of esophagus squamous cell carcinoma (ESCC).

Methods

The lncRNA and mRNA sequencing data were obtained from The Cancer Genome Atlas (TCGA). Tumor grade correlation analysis of lncRNAs and mRNAs was executed, followed by the functional enrichment analysis of all tumor grade‐related mRNAs. The differentially expression mRNAs (DEmRNAs) and differentially expressed lncRNAs (DElncRNAs) were obtained. PPI network and DEmRNA‐DElncRNA interaction analysis were constructed. The functional annotation of the DEmRNAs co‐expressed with DElncRNAs was performed. The expression levels of the candidate genes were validated using qRT‐PCR.

Results

A total of 1864 tumor grade‐related mRNAs (846 positively related and 1018 negatively related) and 552 tumor grade‐related lncRNAs (331 positively related and 221 negatively related) were obtained. The top 10 significantly grade‐related mRNAs and lncRNAs included CA12, FABP4, DECR1, BAIAP2, IL1RAPL2, PPARD, LAD1, TSPAN10, LDOC1, ZNF853, RP11‐25G10.2, RP11‐557H15.3, RP11‐521D12.5, CHKB‐AS1, RP11‐219B4.3, CH17‐335B8.4, RP11‐99 J16‐A.2, CTB‐111H14.1, ADNP‐AS1, and JHDM1D‐AS1. SFN, IL1RAPL2, and RP11‐25G10.2 were overlapped from grade 1, grade 2, and grade 3. PPI network showed that top 10 proteins with higher degrees, including GNAI1, RAP2B, GNAZ, SHH, ADCY1, PRKAR2B, SH3GL1, GNA15, and ARRB1. A DElncRNAs‐nearby DEmRNAs network was constructed to obtain hub lncRNAs including ADAMTS9‐AS2, RP11‐210 M15.2, RP11‐13 K12.1, ZBED3‐AS1, and RP11‐25G10.2. Except for RP11‐25G10.2, ADAMTS9‐AS1, ZBED3‐AS1, SFN, ATP1A2, and GNA15 were consistent with our TCGA analysis.

Conclusions

Alterations of DEmRNAs and DElncRNAs may provide key insights into the molecular mechanisms of ESCC.

miR-1301-3p Promotes Cell Proliferation and Facilitates Cell Cycle Progression via Targeting SIRT1 in Gastric Cancer

So far, many existing evidences indicate that microRNAs (miRNA) are closely associated with the tumorigenesis and progression of various tumors. It has been reported that miR-1301-3p is abnormally expressed in several malignant tumors. However, the role of miR-1301-3p in gastric cancer (GC) remains unclear and is worth studying. Through qRT-PCR, the expression of miR-1301-3p and SIRT1 were detected in GC tissues and cells. The cell proliferation and cell cycle were measured through CCK-8 assay and clone formation assay. Dual luciferase reporter assay was used to determine the target of miR-1301-3p. Though tumorigenesis assay, we monitored the effect of miR-1301-3p on GC cell growth in vivo. miR-1301-3p was upregulated in GC tissues and cells in our study. Overexpression of miR-1301-3p accelerated GC cell proliferation, cell cycle progression and tumorigenesis. Notably, altering the expression miR-1301-3p caused deregulation of Cyclin D1, CDK4, c-Myc and P21. Furthermore, SIRT1 was the direct target of miR-1301-3p by luciferase reporter assay. After transfecting with miR-1301-3p inhibitor, we found that knockdown of SIRT1 could enhance the ability of proliferation. Our results identify miR-1301-3p as a novel potential therapeutic target that is associated with the tumorigenesis and progression of gastric cancer.

Long non-coding RNA SPRY4-IT1 as a promising indicator for three field lymph-node dissection of thoracic esophageal carcinoma

Background

Esophageal squamous cell carcinoma(ESCC) is one of the most common tumors worldwide. Esophagectomy with three-field lymph node dissection(3FLND) is the radical surgical procedure for esophageal cancer. However, 3FLND is not widely used due to it’s higher mortality rate and higher incidence of postoperative complications. There is an urgent need to identify novel biomarkers that can guide the most proper lymph-node dissection in esophageal cancer patients.

Method

Ninety-two patients with thoracic ESCC undergoing 3FLND were enrolled into our study from the Department of Thoracic Surgery of the Fourth Hospital affiliated to the Hebei Medical University and Hebei General Hospital between Jun 2011 and Dec 2015. Retrospectively collected data from these 92 patients was used to explore the relationship between the lymph-node metastasis、recurrence and the SPRY4-IT1 expression level and to determine whether 3FLND should be performed in patients with thoracic ESCC.

Results

The findings revealed that the SPRY4-IT1 expression was significantly higher in esophageal cancer tissues than in adjacent noncancerous tissues. (P < 0.01). Furthermore, the high expression of SPRY4-IT1 was significantly correlated with tumor differentiation (P = 0.029), T classification (P = 0.013), lymph node metastasis(P = 0.022) and pathological stage (P = 0.001). The increased expression of SPRY4-IT1 was associated with a higher risk of cervical and superior mediastinal lymph-node metastasis(P = 0.039).However, no significant association was observed between the risk of cervical and superior mediastinal lymph-node recurrence and the SPRY4-IT1 expression level in the thoracic ESCC patients performed 3FLND(P = 0.509).

Conclusions

Our data support the assumption that the high expression of SPRY4-IT1 is associated with a high risk of lymph node metastasis and it has potential application as a indicator for guiding on three-field lymph node dissection in patients with thoracic ESCC. Randomized controlled trials with a large cohort of patients will be needed to confirm this conclusion in the future.

Long non‑coding RNA LINC00491 promotes proliferation and inhibits apoptosis in esophageal squamous cell carcinoma

Esophageal squamous cell carcinoma (ESCC) is a common malignant tumor in the human digestive system, which affects the physical and mental health of the patient. Long non-coding (lnc)RNAs have been revealed to play an important role in human malignant tumors. Moreover, long intergenic non-protein coding RNA 491 (LINC00491) is a newly discovered lncRNA that can affect the prognosis of cancer. The present study aimed to explore the expression of LINC00491 in ESCC tissues and cells. The reverse transcription-quantitative PCR results suggested that LINC00491 was upregulated in ESCC tissues and cells. LINC00491 expression in esophageal squamous cell carcinoma cells were knocked down. Cell Counting Kit-8, wound healing, Transwell and apoptosis assays were performed to detect the effects of LINC00491 knockdown on cell biological behavior. The results showed that lower expression of LINC00491 resulted in decreased cell proliferation and migration and increased the apoptosis rate. Therefore, the present results indicated that lncRNA LINC00491 promoted the biological processes of ESCC, and thus LINC00491 may be a potential therapeutic target for ESCC.

Evaluation of Serum Exosomal lncRNAs as Diagnostic and Prognostic Biomarkers for Esophageal Squamous Cell Carcinoma

Background

Exosomal long non-coding RNAs (lncRNAs) have been recognised as promising stable biomarkers in cancers. The aim of this study was to identify an exosomal lncRNA panel for diagnosis and prognosis of esophageal squamous cell carcinoma (ESCC).

Materials and Methods

Exosomes were isolated from serum by ExoQuick Solution. To validate the exosomes, exosomal markers and characterization of nanoparticle were performed. Quantitative real-time PCR was used to measure the levels of lncRNAs in exosomes from ESCC patients and healthy subjects. In the training set, exosomal lncRNA profiles from 404 samples were conducted and established new models by multivariate logistic regression. In the validation set, the diagnostic performance of the panel was further validated in 222 additional individuals with a receiver operating characteristic curve (ROC). Kaplan-Meier and multivariate Cox proportional hazards analysis were applied to assess the correlation between lncRNAs and survival rate of ESCC patients.

Results

A 4-lncRNA panel (UCA1, POU3F3, ESCCAL-1 and PEG10) in exosomes for ESCC diagnosis was developed by logistic regression model. The diagnostic accuracy of panel was evaluated with AUC value of 0.844 and 0.853 for training and validation stage, respectively. The corresponding AUCs for patients with TNM stage I-II and III were 0.820 and 0.935, significantly higher than squamous cell carcinoma antigen (P<0.001), which were 0.652 and 0.642, respectively. Kaplan-Meier analysis indicated that patients with higher level of UCA1 and POU3F3 had lower survival rate (P<0.001). Additionally, POU3F3 might be as an independent prognostic factor for ESCC patients (P=0.004).

Conclusion

These findings suggested that serum exosomal 4-lncRNA panel has considerable value for ESCC diagnosis, and POU3F3 may serve as a novel and independent prognostic predictor in clinical applications.

CKS1B as Drug Resistance-Inducing Gene-A Potential Target to Improve Cancer Therapy

Cancer is a threat to human health and life. Although previously centered on chemical drug treatments, cancer treatment has entered an era of precision targeted therapy. Targeted therapy entails precise guidance, allowing the selective killing of cancer cells and thereby reducing damage to healthy tissues. Therefore, the need to explore potential targets for tumor treatment is vital. Cyclin-dependent kinase regulatory subunit 1B (CKS1B), a member of the conserved cyclin kinase subunit 1 (CKS1) protein family, plays an essential role in cell cycling. A large number of studies have shown that CKS1B is associated with the pathogenesis of many human cancers and closely related to drug resistance. Here, we describe the current understanding of the cellular functions of CKS1B and its underlying mechanisms, summarize a recent study of CKS1B as a target for cancer treatment and discuss the potential of CKS1B as a therapeutic target.

RNA sequencing-based microRNA expression signature in esophageal squamous cell carcinoma: oncogenic targets by antitumor miR-143-5p and miR-143-3p regulation

Aberrantly expressed microRNAs (miRNAs) disrupt intracellular RNA networks and contribute to malignant transformation of cancer cells. Utilizing the latest RNA sequencing technology, we newly created the miRNA expression signature of esophageal squamous cell carcinoma (ESCC). A total of 47 miRNAs were downregulated in ESCC tissues, and these miRNAs were candidates for antitumor miRNAs in ESCC cells. Analysis of the signature revealed that several passenger strands of miRNAs were significantly downregulated in ESCC, e.g., miR-28-3p, miR-30a-3p, miR-30c-3p, miR-133a-3p, miR-139-3p, miR-143-5p, and miR-145-3p. Recent studies indicate that some passenger strands of miRNAs closely involved in cancer pathogenesis. In this study, we focused on both strands of pre-miR-143, and investigated their antitumor roles and target oncogenes in ESCC. Ectopic expression of miR-143-5p and miR-143-3p significantly attenuated malignant phenotypes (e.g., proliferation, migration, and invasive abilities) in ESCC cell lines. We revealed that six genes (HN1, HMGA2, NETO2, STMN1, TCF3, and MET) were putative targets of miR-143-5p regulation, and one gene (KRT80) was a putative target of miR-143-3p regulation in ESCC cells. Our ESCC miRNA signature and analysis strategy provided important insights into the molecular pathogenesis of ESCC.

LncRNA SNHG1 Regulates the Progression of Esophageal Squamous Cell Cancer by the miR-204/HOXC8 Axis

Objective

Long noncoding RNA small nucleolar RNA host gene 1 (SNHG1) has been reported to be aberrantly expressed and plays an important role in human cancers, including esophageal squamous cell cancer. However, the regulatory mechanism underlying SNHG1 in the progression of esophageal squamous cell cancer is poorly defined.

Materials and Methods

Fifty-three esophageal squamous cell cancer patients were recruited and overall survival was analyzed. EC9706 and KYSE150 cells were cultured for study in vitro. The expression levels of SNHG1, microRNA (miR)-204 and homeobox c8 (HOXC8) were detected by quantitative real-time polymerase chain reaction and Western blot. Cell cycle distribution, apoptosis, migration and invasion were determined by flow cytometry and transwell assays, respectively. The target interaction among SNHG1, miR-204 and HOXC8 was validated by luciferase reporter assay and RNA immunoprecipitation. Xenograft model was established to investigate the role of SNHG1 in vivo.

Results

High expression of SNHG1 was exhibited in esophageal squamous cell cancer and indicated poor outcomes of patients. SNHG1 silence led to cell cycle arrest at G0-G1 phase, inhibition of migration and invasion and increase of apoptosis. miR-204 was validated to sponge by SNHG1 and target HOXC8 in esophageal squamous cell cancer cells. miR-204 knockdown or HOXC8 restoration reversed the inhibitive role of SNHG1 silence in the progression of esophageal squamous cell cancer cells. Furthermore, inhibiting SNHG1 decreased xenograft tumor growth by regulating miR-204 and HOXC8.

Conclusion

SNHG1 knockdown suppresses migration and invasion but induces apoptosis of esophageal squamous cell cancer cells by increasing miR-204 and decreasing HOXC8.

Identification of a nomogram based on long non-coding RNA to improve prognosis prediction of esophageal squamous cell carcinoma

PURPOSE

Esophageal squamous cell carcinoma (ESCC) remains a common aggressive malignancy in the world. Several long non-coding RNAs (lncRNAs) are reported to predict the prognosis of ESCC. Therefore, an in-depth research is urgently needed to further investigate the prognostic value of lncRNAs in ESCC.

RESULTS

From the training set, we identified a eight-lncRNA signature (including AP000487, AC011997, LINC01592, LINC01497, LINC01711, FENDRR, AC087045, AC137770) which separated the patients into two groups with significantly different overall survival (hazard ratio, HR = 3.79, 95% confidence interval, 95% CI [2.56-5.62]; P < 0.001). The signature was applied to the validation set (HR = 2.73, 95%CI [1.65-4.53]; P < 0.001) and showed similar prognostic values. Stratified, univariate and multivariate Cox regression analysis indicated that the signature was an independent prognostic factor for patients with ESCC. A nomogram based on the lncRNAs signature, age, grade and stage was developed and showed good accuracy for predicting 1-, 3- and 5-year survival probability of ESCC patients. We found a strong correlation between the gene significance for the survival time and T stage. Eight modules were constructed, among which the key module most closely associated with clinical information was identified.

CONCLUSIONS

Our eight-lincRNA signature and nomogram could be practical and reliable prognostic tools for esophageal squamous cell carcinoma.

METHODS

We downloaded the lncRNA expression profiles of ESCC patients from Gene Expression Omnibus (GEO) and The Cancer Genome Atlas (TCGA) datasets and separated to training and validation cohort. The univariate, least absolute shrinkage and selection operator (LASSO) and multivariate Cox regression analysis were used to identify a lncRNA-based signature. The predictive value of the signature was assessed using the Kaplan-Meier method, receiver operating characteristic (ROC) curves and area under curve (AUC). Weighted gene co-expression network analysis (WGCNA) was applied to predict the intrinsic relationship between gene expressions. In addition, we further explored the combination of clinical information and module construction.

Identification of BRMS1L as Metastasis Suppressing Gene in Esophageal Squamous Cell Carcinoma

Introduction

Breast cancer metastasis suppressor 1 like (BRMS1-like)was first reported to be a component of the Sin3-HDAC complex, but the role in the progression of cancers was largely unknown. Our previous study reported that BRMS1L promoted the metastasis of breast cancer through facilitating the recruitment of HDAC complex to the promoter FZD10, and hence suppressing the transcription of FZD10.

Methods

In this study, we detected the expression level of BRMS1L in esophageal squamous cell carcinoma (ESCC). The effect of BRMS1L in TE-1D (knockdown) and ECA-109 (overexpression) cell lines was explored by transwell assays, wound healing assays, and cell adhesion assays. Quantitative real‑time PCR, Western blot analysis, and luciferase assays were used to detect the interaction of the CBP/P300-BRMS1L-ITGA7 axis.

Results

In the present study, we found that knockdown of BRMS1L promoted the migration, invasion, and epithelial-mesenchymal transition (EMT). Conversely, overexpression of BRMS1L inhibited the migration and invasion of ESCC. Mechanistically, BRMS1L exerted their metastasis-suppressing role via transcriptionally repress ITGA7 expression. Moreover, we revealed that CBP/p 300 regulated the expression of BRMS1L and might be responsible for the down-regulation of BRMS1L in ESCC.

Conclusion

Collectively, we identified the role of CBP/p300-BRMS1L-ITGA7 axis in the metastasis of ESCC.

Comprehensive biological function analysis of lncRNAs in hepatocellular carcinoma

Thousands of long non-coding RNAs (lncRNAs) have been discovered in human genomes by gene chip, next-generation sequencing, and/or other methods in recent years, which represent a significant subset of the universal genes involved in a wide range of biological functions. An abnormal expression of lncRNAs is associated with the growth, invasion, and metastasis of various types of human cancers, including hepatocellular carcinoma (HCC), which is an aggressive, highly malignant, and invasive tumor, and a poor prognosis in China. With a more in-depth understanding of lncRNA research for HCC and the emergence of new molecular-targeted therapies, the diagnosis, treatment, and prognosis of HCC will be considerably improved. Therefore, this review is expected to provide recommendations and directions for future lncRNA research for HCC.

Emerging Role of Non-Coding RNAs in Esophageal Squamous Cell Carcinoma

Esophageal squamous cell carcinoma (ESCC) is a highly prevalent tumor and is associated with ethnicity, genetics, and dietary intake. Non-coding RNAs (ncRNAs), specifically microRNAs (miRNAs), long ncRNAs (lncRNAs), and circular RNAs (circRNAs) have been reported as functional regulatory molecules involved in the development of many human cancers, including ESCC. Recently, several ncRNAs have been detected as oncogenes or tumor suppressors in ESCC progression. These ncRNAs influence the expression of specific genes or their associated signaling pathways. Moreover, interactions of ncRNAs are evident in ESCC, as miRNAs regulate the expression of lncRNAs, and further, lncRNAs and circRNAs function as miRNA sponges to compete with the endogenous RNAs. Here, we discuss and summarize the findings of recent investigations into the role of ncRNAs (miRNAs, lncRNAs, and circRNAs) in the development and progression of ESCC and how their interactions regulate ESCC development.

LINC01518 knockdown inhibits tumorigenicity by suppression of PIK3CA/Akt pathway in oesophageal squamous cell carcinoma

LncRNA LINC01518 was previously reported to be upregulated in oesophageal squamous cell carcinoma (ESCC) tissues compared with normal tissues. However, there are no previous studies concerning the specific function and molecular mechanism of LINC01518 in ESCC. LINC01518 and miR-1-3p expression levels in ESCC cells were detected by qRT-PCR. Cell proliferation and apoptosis were evaluated by CCK-8 and flow cytometry analysis, respectively. The relationships between LINC01518, phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit α (PIK3CA) and miR-1-3p were explored by luciferase reporter assay. The alteration of the PIK3CA/protein kinase B (Akt) pathway was examined by Western blot. We found that LINC01518 expression was upregulated and miR-1-3p expression was downregulated in ESCC cells. LINC01518 knockdown inhibited cell proliferation and promoted apoptosis in ESCC cells. In addition, LINC01518 functioned as a competing endogenous RNA (ceRNA) for miR-1-3p in ESCC cells and miR-1-3p downregulation blocked the effects of LINC01518 knockdown on cell proliferation and apoptosis in ESCC cells. Moreover, PIK3CA was identified as a target of miR-1-3p and LINC01518 knockdown inhibited the PIK3CA/Akt pathway by upregulating miR-1-3p in ESCC cells. In conclusion, LINC01518 knockdown inhibited tumorigenicity in ESCC cells by suppression of PIK3CA/Akt pathway through upregulating miR-1-3p.

miR-145 sensitizes esophageal squamous cell carcinoma to cisplatin through directly inhibiting PI3K/AKT signaling pathway

Background

Esophageal squamous cell carcinoma (ESCC) is the eighth most common cancer worldwide and is one of the most lethal malignancies. Cisplatin (DDP) is a key drug for ESCC treatment, but the presence of chemotherapy resistance limits the use of DDP. To enhance chemosensitivity to DDP is important for ESCC treatment.

Methods

qRT-PCR and Western blotting detected mRNA and protein expression in ESCC tissues and cells. Luciferase reporter assay assessed the interaction between miR-145 and AKT3. Cell cycle, apoptosis and proliferation were investigated with flow cytometry and MTT assay, respectively. Nude mice xenograft model was established, and immunohistochemistry (IHC) and TUNEL assay were conducted to detect Ki-67 level and apoptosis in xenograft tumor.

Results

Down-regulated miR-145 and up-regulated AKT3 were observed in ESCC tissues and cells. Luciferase reporter assay revealed that miR-145 negatively regulated AKT3 through binding to its 3′-UTR. Overexpression of miR-145 or knockdown of AKT3 promoted DDP-induced cell cycle arrest and apoptosis, as well as reduced IC50 of DDP treatment, which was reversed by AKT3 overexpression. The expression level of MRP1, P-gp, CyclinD1, c-Myc and anti-apoptotic protein Bcl-2 were down-regulated, while pro-apoptotic protein Bax was up-regulated by miR-145. Furthermore, overexpression of miR-145 enhanced the DDP-induced tumor growth suppression in vivo.

Conclusion

miR-145 increased the sensitivity of ESCC to DDP, and facilitated DDP-induced apoptosis, cycle arrest by directly inhibiting PI3K/AKT signaling pathway to decrease multidrug resistance-associated proteins MRP1 and P-gp expression. Improving the efficacy of DDP by boosting the miR-145 level provides a new strategy for treatment of ESCC.

Linc-ROR regulates apoptosis in esophageal squamous cell carcinoma via modulation of p53 ubiquitination by targeting miR-204-5p/MDM2

The long intergenic noncoding RNA, regulator of reprogramming (linc-ROR) has been reported to participate in tumorigenesis, while its functions and fundamental mechanisms in esophageal squamous cell carcinoma (ESCC) remain unclear. In this study, gain-of-function assays showed that linc-ROR upregulation enhanced cell viability, promoted cell proliferation, and inhibited apoptosis. Mechanistically, the regulatory network of linc-ROR/miR-204-5p/MDM2 was established with bioinformatics analysis and online databases, then validated via dual-luciferase reporter assays, RNA immunoprecipitation assays in ESCC cells. Linc-ROR positively regulates the expression of MDM2 as a molecular sponge of miR-204-5p. Moreover, results of western blot and coimmunoprecipitation indicated that linc-ROR overexpression enhanced the ubiquitination level of p53, and its downstream apoptosis-related genes have showed higher bcl-2 expression, lower bax, and cleaved caspase-3 expressions, while miR-204-5p could counteract with this effect. Finally, small interfering RNAs tailored to linc-ROR were established to further evaluate its effects on ESCC comprehensively. In summary, this study revealed that linc-ROR modulated cell apoptosis and regulated p53 ubiquitination via targeting miR-204-5p/MDM2 axis, which provides a novel therapeutic insight into treatments for ESCC.

Prognostic alternative splicing signatures and underlying regulatory network in esophageal carcinoma

Alternative splicing (AS) has been widely reported to play an important role in cancers, including esophageal carcinoma (ESCA). However, no study has comprehensively investigated the clinical use of combination of prognostic AS events and clinicopathological parameters. Therefore, we collected 165 ESCA patients including 83 esophageal adenocarcinoma (EAC) and 82 esophageal squamous cell carcinoma (ESCC) patients from The Cancer Genome Atlas to explore the survival rate associated with seven types of AS events. Prognostic predictors for the clinical outcomes of ESCA patients were built. Predictive prognosis models of the alternative acceptor site in ESCA (area under the curve [AUC] = 0.83), alternative donor site in EAC (AUC = 0.99), and alternative terminator site in ESCC (AUC = 0.974) showed the best predictive efficacy. A novel combined prognostic model of AS events and clinicopathological parameters in ESCA was also constructed. Combined prognostic models of ESCA all showed better predictive efficacy than independent AS models or clinicopathological parameters model. Through constructing splicing regulatory network, the expression of AS factor was found to be negatively correlated with the most favorable AS events. Moreover, gene amplification, mutation, and copy number variation of AS genes were commonly observed, which may indicate the molecular mechanism of how the AS events influence survival. Conclusively, the constructed prognostic models based on AS events, especially the combined prognostic models of AS signatures and clinicopathological parameters could be used to predict the outcome of ESCA patients. Moreover, the splicing regulatory network and genomic alteration in ESCA could be used for illuminating the potential molecular mechanism.

Long non‑coding RNA DLX6‑AS1 is associated with malignant progression and promotes proliferation and invasion in esophageal squamous cell carcinoma

Despite being one of the most prevalent and fatal types of cancer worldwide, the biological details of esophageal squamous cell carcinoma (ESCC) remain unknown. Recent studies have demonstrated the crucial roles of long non‑coding RNAs (lncRNAs) in diverse biological processes including cancer initiation, progression and metastasis. The aim of the present study was to assess the expression profile of distal‑less homeobox 6 antisense RNA 1 (DLX6‑AS1) in ESCC tissues and its contributions to ESCC cell proliferation, apoptosis and invasion. The expression of DLX6‑AS1 in a series of ESCC samples and paired adjacent noncancerous tissues was evaluated by reverse transcription‑quantitative polymerase chain reaction. Cell proliferation, apoptosis, wound healing and Transwell invasion assays were performed to evaluate the roles of DLX6‑AS1 in the ESCC cell lines EC109 and KYSE30 transfected with DLX6‑AS1 small interfering RNA (siRNA). Compared with the paired adjacent noncancerous tissues, DLX6‑AS1 expression was upregulated in the ESCC tissues and significantly associated with differentiation status, Tumor‑Node‑Metastasis stage, distant metastasis, and lymph node metastasis. Knockdown of DLX6‑AS1 significantly suppressed cell proliferation, invasion and migration abilities, and enhanced the apoptotic rate in the two ESCC cell lines. Furthermore, western blot assays revealed that silencing DLX6‑AS1 partly influenced the epithelial‑mesenchymal transition process in ESCC cells. These results imply that the oncogenic function of DLX6‑AS1 may be a novel candidate target for treating human ESCC.

miR-32 promotes esophageal squamous cell carcinoma metastasis by targeting CXXC5

MicroRNA-32 (miR-32) functioned as a tumor oncogene in some cancer, which control genes involved in important biological and pathological functions and facilitate the tumor growth and metastasis. However, the role of miR-32 modulates esophageal squamous cell carcinoma (ESCC) malignant transformation has not been clarified. Here, we focused on the function and the underlying molecular mechanism of miR-32 in ESCC. Results discovered a significant increased expression of miR-32 in ESCC tissues and cells. Downregulation of miR-32 inhibited the migration, invasion, adhesion of ESCC cell lines (EC9706 and KYSE450), and the levels of EMT protein in vitro. In vivo, miR-32 inhibitors decrease tumor size, tumor weight, and the number of metastatic nodules. Hematoxylin and eosin (H&E) results revealed that inhibition of miR-32 attenuate lung metastasis. Immunohistochemistry and immunofluorescence assay showed increased level of E-cadherin and decreased level of N-cadherin and Vimentin with treatment of miR-32 inhibitors. Furthermore, miR-32 targeted the 3'-untranslated region (3'-UTR) of CXXC5, and inhibited the level of mRNA and protein of CXXC5. There is a negative correlation between the expressions of CXXC5 and miR-32. Then, after EC9706 and KYSE450 cells cotransfected with si-CXXC5 and miR-32 inhibitors, the ability of cell migration, invasion, and adhesion was significantly reduced. In addition, the protein expression of EMT and TGF-β signaling was also depressed. Collectively, these data supply an insight into the positive role of miR-32 in ESCC progression and metastasis, and its biological effects may attribute the inhibition of TGF-β signaling mediated by CXXC5.

Downregulation of SNHG1 suppresses cell proliferation and invasion by regulating Notch signaling pathway in esophageal squamous cell cancer

BACKGROUND

Long non-coding RNAs (lncRNAs) exert important functions involved in tumorigenesis and cancer progression including esophageal squamous cell cancer (ESCC), however, the clinical role and underlying biological function of Small Nucleolar RNA Host Gene 1 (SNHG1) in ESCC is not well known.

METHODS

Quantitative Real-time polymerase chain reaction (QRT-PCR) was used to detect the SNHG1 expression levels in ESCC tissues and adjacent non-cancerous tissues. Chi-square test was used to evaluate the association between clinicopathological features and SNHG1 expression in ESCC patients, Kaplan-Meier curve and log rank test was performed to analyze the association between overall survival and SNHG1 expression. Cell proliferation and invasion was assessed by MTT assay, colony formation, and transwell cell invasion assays. Western blot were also performed to examine protein expression levels of E-cadherin, Vimentin and N-cadherin, Notch 1 and Hes-1.

RESULTS

We demonstrated that lncRNA SNHG1 was significantly up-regulated in ESCC tissues compared with adjacent non-cancerous tissues in ESCC patients. Meanwhile, increased lncRNA SNHG1 expression levels markedly correlated with lymph node metastasis, depth of invasion, TNM stage and reduced over survival time in ESCC patients. Furthermore, MTT assay, colony formation, transwell cell invasion, qRT-PCR and Western-blot assays demonstrated that knockdown of lncRNA SNHG1 could inhibit cell proliferation and cell invasion capacity and cell Epithelial-Mesenchymal Transition (EMT) phenomenon by up-regulation E-cadherin and down-regulating Vimentin and N-cadherin in ESCC cells. Besides, we demonstrated that knockdown of SNHG1 suppressed the Notch signaling pathway by reducing the Notch1 and Hes-1 expression levels in ESCC cells.

CONCLUSIONS

These results indicated that lncRNA SNHG1 may be a potential predictor of prognosis in ESCC patients and a novel target for ESCC treatment.

LncRNA BDNF-AS inhibits proliferation, migration, invasion and EMT in oesophageal cancer cells by targeting miR-214

This study was aimed at exploring the effect of lncRNA BDNF-AS on cell proliferation, migration, invasion and epithelial-to-mesenchymal transition (EMT) of oesophageal cancer (EC) cells. The expression of BDNF-AS and miR-214 in tissue samples and cells was measured by qRT-PCR. The targeted relationship between BDNF-AS and miR-214 was analysed by dual-luciferase reporter assay. After cell transfection, the cell proliferation activity was assessed by MTS method, while the migrating and invading abilities were evaluated by transwell assay. LncRNA BDNF-AS was remarkably down-regulated, while miR-214 was up-regulated in EC tissues and cells in comparison with normal tissues and cells. Overexpression of BDNF-AS significantly inhibited the abilities of cell proliferation, migration and invasion as well as the EMT processes of EC cells. The bioinformatics analysis and luciferase assay indicated that BDNF-AS could be directly bound by miR-214. Furthermore, overexpression of miR-214 and BDNF-AS exerted suppressive influence on EC cell multiplication, migration, invasion and EMT processes. LncRNA BDNF-AS restrained cell proliferation, migration, invasion and EMT processes in EC cells by targeting miR-214.

C-terminal binding protein‑2 mediates cisplatin chemoresistance in esophageal cancer cells via the inhibition of apoptosis

C-terminal binding protein‑2 (CtBP2) is a transcriptional co-repressor that is associated with tumorigenesis and tumor progression. It has been reported to predict a poor prognosis in several human cancers, including esophageal squamous cell carcinoma (ESCC). The present study aimed to investigate the involvement of CtBP2 in the cisplatin (DDP) resistance of the ECA109 ESCC cell line and its effect on the expression of apoptosis-associated proteins. Constructed recombinant lentiviruses were used for the knockdown or overexpression of CtBP2 in ECA109 cells, and the expression of CtBP2 was measured using reverse transcription-quantitative polymerase chain reaction and western blotting following transfection. MTT assays, Hoechst 33342 staining and flow cytometry (FCM) were applied to detect the influence of CtBP2 on the DDP-induced viability and apoptosis of the transfected ECA109 cells. In addition, the levels of apoptosis-associated proteins, including p53, B‑cell lymphoma 2 (Bcl‑2), Bcl‑2‑associated X protein (Bax) and activated caspase-3 were investigated in the transfected ECA109 cells. Stable ECA109 cells with CtBP2 overexpression or knockdown were successfully established. The results of the MTT, Hoechst 33342 and FCM assays demonstrated that overexpression of CtBP2 attenuated the reduction of cell viability and inhibited the cell apoptosis induced by DDP. Furthermore, the western blotting results indicated that CtBP2 overexpression inhibited the DDP-induced apoptosis of ECA109 cells via the reduction of p53, activated caspase-3 and Bax expression, and promotion of Bcl‑2 expression. Therefore, the present study indicated that CtBP2 reduced the susceptibility of ECA109 cells to DDP by regulating the expression of apoptosis-related proteins, suggesting that it may be a promising therapeutic target in ESCC in the future.

Non-coding RNAs: new biomarkers and therapeutic targets for esophageal cancer

Esophageal cancer is one of the most common gastrointestinal malignant diseases and there is still no effective treatment. The incidence of esophageal cancer in the world is relatively high and on the increase year by year. Thus, the elaboration on the carcinogenesis of esophageal cancer and the identification of new biomarkers and therapeutic targets is quite beneficial to optimizing the current therapeutic regimen for treating such deadly disease. More and more evidence has shown that non-coding RNAs play an important role in the development and progression of multiple human cancers, including esophageal cancer. microRNAs (miRNAs) and long non-coding RNAs (lncRNAs) are two functional kinds of non-coding RNAs that have been well investigated. They exert tumor suppressive or promoting effect by specifically regulating the expression of certain downstream target genes, which is tumor specific. It is also proved that miRNAs and lncRNAs level in tissue and plasma from esophageal cancer patients are closely correlated with the survival and disease progression, which could be used as a prognostic factor and therapeutic target for esophageal cancer.

Long Non-Coding RNA SPRY4-IT1 Can Predict Poor Prognosis in Digestive System Malignancies: a Meta-Analysis

Recent studies have reported that long non-coding RNA SPRY4 intron transcript 1 (SPRY4-IT1) is abnormally expressed in malignant digestive tumors and associated with prognosis. But its clinical relevance is unclear. Here, we performed a meta-analysis aims to evaluate the prognostic value of SPRY4-IT1 in digestive system malignancies. We systematic search the PubMed, Web of Science, ScienceDirect and Wiley Online Library database to eligible studies. The pooled hazard ratios (HRs) with a 95% confidence interval (95% CI) were calculated to explored the association of lncRNA SPRY4-IT1 with prognosis. Five studies were eligible for analysis, a total of 518 patients were included. Meta-analysis indicated that overexpression of SPRY4-IT1 was associated with poor over survival (OS) (HR = 1.24, 95%CI:0.49-1.98; random-effects model). The clinicopathological parameters analysis further showed that increased expression level of SPRY4-IT1 was positively correlated with lymph node metastasis (HR = 1.45, 95% CI =0.88-2.02; fixed-effects model), TNM stage (HR = 1.24,95% CI = 0.78-1.70; fixed-effects model), and invasion depth (HR = 1.25,95% CI = 0.63-1.88; fixed-effects model). lncRNA SPRY4-IT1 may serve as a potential prognostic marker in malignant digestive tumors.

Comprehensive analysis of differential co-expression patterns reveal transcriptional dysregulation mechanism and identify novel prognostic lncRNAs in esophageal squamous cell carcinoma

Esophageal squamous cell carcinoma (ESCC) is one of the most common malignancies worldwide and occurs at a relatively high frequency in People's Republic of China. However, the molecular mechanism underlying ESCC is still unclear. In this study, the mRNA and long non-coding RNA (lncRNA) expression profiles of ESCC were downloaded from the Gene Expression Omnibus database, and then differential co-expression analysis was used to reveal the altered co-expression relationship of gene pairs in ESCC tumors. A total of 3,709 mRNAs and 923 lncRNAs were differentially co-expressed between normal and tumor tissues, and we found that most of the gene pairs lost associations in the tumor tissues. The differential regulatory networking approach deciphered that transcriptional dysregulation was ubiquitous in ESCC, and most of the differentially regulated links were modulated by 37 TFs. Our study also found that two novel lncRNAs (ADAMTS9-AS1 and AP000696.2) might be essential in the development of ectoderm and epithelial cells, which could significantly stratify ESCC patients into high-risk and low-risk groups, and were much better than traditional clinical tumor markers. Further inspection of two risk groups showed that the changes in TF-target regulation in the high-risk patients were significantly higher than those in the low-risk patients. In addition, four signal transduction-related DCmRNAs (ERBB3, ENSA, KCNK7, MFSD5), which were differentially co-expressed with the two lncRNAs, might also have the predictive capacity. Our findings will enhance the understanding of ESCC transcriptional dysregulation from a view of cross-link of lncRNA and mRNA, and the two-lncRNA combination may serve as a novel prognostic biomarker for clinical applications of ESCC.

Long noncoding RNA MALAT1 affects the efficacy of radiotherapy for esophageal squamous cell carcinoma by regulating Cks1 expression

OBJECTIVE

Long noncoding RNA metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) has been well studied in the progression of many malignancies. However, its association with the radioresistance of tumors has not been well understood yet. This study tried to explore the role of MALAT1 in regulating the radiosensitivity of esophageal cancer (EC), especially esophageal squamous cell carcinoma (ESCC), involving its regulation on Cks1 expression.

METHODS

KYSE150 cells were subcutaneously inoculated into nude mice to establish ESCC xenografts. Real-time PCR and Western blot analysis were performed to detect the expression of MALAT1 and Cks1 in irradiated xenografts and cells. Functional analysis was performed in both EC9706 and KYSE150 cells via the transfection of corresponding plasmids or small interfering RNAs (siRNAs). Irradiation-induced damage was examined by the detection of cell viability and apoptosis using MTT and TUNEL assays, respectively.

RESULTS

Both MALAT1 and Cks1 were downregulated in irradiated xenografts and cells. Cks1FER1L4 showed significant downregulation. Overexpression of MALAT1 inhibited irradiation-induced decrease in cell viability, increase in apoptosis, and downregulation of Cks1. Cks1 expression was also downregulated by MALAT1 siRNA, while Cks1 siRNA strongly recovered MALAT1-induced radioresistance in vitro. Moreover, better tumor growth, accompanied by Cks1 upregulation, was observed in KYSE150 xenografts with MALAT1 overexpression, especially under radiation treatment.

CONCLUSION

MALAT1 acted as one positive regulator of the radioresistance of ESCC, at least partly due to its promotion on Cks1 expression. Furthermore, MALAT1-targeted therapies showed great potential in enhancing the radiotherapeutic effect on ESCC.

Serum microRNA-15a level acts as a potential diagnostic and prognostic biomarker for human esophageal squamous cell carcinoma

BACKGROUND

Clinical significance of microRNA (miR)-15a in human esophageal squamous cell carcinoma (ESCC) remains unclear.

OBJECTIVE

To evaluate the expression level of miR-15a and to determine its potential for diagnosis and prognosis in ESCC.

METHODS

Quantitative reverse transcription polymerase chain reaction was performed to examine the expression levels of miR-15a in ESCC tissues and patients' sera. The diagnostic and prognostic implications of serum miR-15a level in human ESCC were further evaluated.

RESULTS

Expression levels of miR-15a in ESCC tissues and patients' sera were significantly decreased (both P< 0.001). Additionally, serum miR-15a had an optimal diagnostic cut-off point (2.29) for ESCC with sensitivity of 86.36% and specificity of 100.00%. Moreover, low serum miR-15a level more frequently occurred in ESCC patients with advanced tumor-node-metastasis, T and N stages (all P= 0.01) and poor tumor differentiation (P= 0.03). The Kaplan-Meier curve showed that low miR-15a expression was significantly associated with shorter overall survival (OS) and disease-free survival (DFS) of ESCC patients (both P< 0.001). Further multivariate analysis identified miR-15a as an independent prognostic factor for both OS and DFS (both P= 0.01).

CONCLUSION

Decreased expression of miR-15a may play a crucial role in ESCC development and progression. Serum miR-15a level could be used as a potential diagnostic and prognostic marker in clinics.

MicroRNAs and long non-coding RNAs in digestive system malignancies

The mammalian transcriptome includes a large number of microRNAs (miRNAs) and long non-coding RNAs (lncRNAs). Some studies have reported that numerous kinds of miRNAs and lncRNAs have been implicated in playing key regulatory roles in the occurrence and development of digestive system malignances. Therefore, they are closely related to the clinical diagnosis, treatment and prognosis of digestive system malignances. This review focuses on the recent progress in research of miRNAs and lncRNAs in in digestive system malignancies and discusses their epigenetics roles as oncogenes or tumor suppressors. The current and future potential clinical applications of miRNAs and lncRNAs in digestive system malignancies are also discussed, with an aim to provide new ideas and means for the diagnosis, treatment and prognosis of digestive system malignancies.

Long noncoding RNAs are novel potential prognostic biomarkers for esophageal squamous cell carcinoma: an overview

Esophageal squamous cell carcinoma (ESCC) still has a poor prognosis. The prognostic biomarkers of ESCC are not yet well established. Long noncoding RNAs (lncRNAs) have recently been intensively investigated in various cancers including ESCC, and are found to be closely correlated to ESCC. Dysregulated expression of lncRNAs was widely observed in ESCC tumor tissue and was closely related to the tumorigenesis and progression of ESCC. More and more studies have found that lncRNAs were significantly correlated with the prognosis and diagnosis of patients with ESCC. Therefore, all those accumulating evidence indicated that lncRNAs could serve as a prognostic biomarker of ESCC. In this, we summarized the relation between lncRNAs and ESCC as well as the potential biomarker role of lncRNAs in ESCC, especially the prognostic value of lncRNAs. Our current review highlighted the need of further studies to explore the biomarker functions as well as therapeutic values of lncRNAs in ESCC.

miR-200b induces cell cycle arrest and represses cell growth in esophageal squamous cell carcinoma

miR-200b is a pleiotropically acting microRNA in cancer progression, representing an attractive therapeutic target. We previously identified miR-200b as an invasiveness repressor in esophageal squamous cell carcinoma (ESCC), whereas further understanding is warranted to establish it as a therapeutic target. Here, we show that miR-200b mitigates ESCC cell growth by inducing G2-phase cell cycle arrest and apoptosis. The expression/activation of multiple key cell cycle regulators such as CDK1, CDK2, CDK4 and Cyclin B, and the Wnt/β-Catenin signaling are modulated by miR-200b. We identified CDK2 and PAF (PCNA-associated factor), two important tumor-promoting factors, as direct miR-200b targets in ESCC. Correlating with the frequent loss of miR-200b in ESCC, both CDK2 and PAF levels are significantly increased in ESCC tumors compared to case-matched normal tissues (n = 119, both P < 0.0001), and correlate with markedly reduced survival (P = 0.007 and P = 0.041, respectively). Furthermore, CDK2 and PAF are also associated with poor prognosis in certain subtypes of breast cancer (n = 1802) and gastric cancer (n = 233). Although CDK2 could not significantly mediate the biological function of miR-200b, PAF siRNA knockdown phenocopied while restored expression of PAF abrogated the biological effects of miR-200b on ESCC cells. Moreover, PAF was revealed to mediate the inhibitory effects of miR-200b on Wnt/β-Catenin signaling. Collectively, the pleiotropic effects of miR-200b in ESCC highlight its potential for therapeutic intervention in this aggressive disease.

Downregulation of long non-coding RNA HCG11 predicts a poor prognosis in prostate cancer

Long non-coding RNAs (lncRNA) have been reported as key regulators in the progression and metastasis of prostate cancer (PCa). In this study, we found that the expression levels of HCG11 in PCa tissues were significantly lower than those in non-tumor tissues in publically available databases and in human PCa samples. Our results showed the expression levels of HCG11 in patients with PCa were associated with the age, Lymph Node Status (LN status), preoperative PSA level, Gleason score, and biochemical recurrence (BCR). Kaplan-Meier analysis indicated that downregulation of HCG11 expression in tissues was associated with poor survival of PCa patients. GO and KEGG pathway analysis were applied to explore the potential roles of HCG11. Moreover, a HCG11 mediated ceRNA network was built using co-expression relationships of the differentially expressed mRNAs and miRNAs. We believed that this study will provide a potential new therapeutic and prognostic target for prostate cancer.

Involvement of microRNA-1297, a new regulator of HMGA1, in the regulation of glioma cell growth in vivo and in vitro

MicroRNAs (miRNAs) are a class of versatile gene expression regulators, participating in the regulation of gene expression at the post-transcriptional level in both physiological and pathological conditions. Gliomas are the most common brain malignancy in adults, and deregulation of microRNAs takes part in the gliomagenesis process. Here, we found that the expression of miR-1297 is significantly reduced in both glioma cell lines and clinical glioma tissues. Using the MTT assay, soft agar colony formation assay and xenograft tumor formation assay, we show that miR-1297 is a tumor suppressor microRNA in gliomas. We demonstrate that the high mobility group protein A1 (HMGA1) is the functional target of miR-1297 in glioma cells. HMGA1 significantly promotes the growth of glioma cells both in vitro and in vivo. Together, we unveil a new molecular mechanism in gliomas that may shed new light on understanding this brain malignancy.