MicroRNAs in esophageal squamous cell carcinoma: Potential biomarkers and therapeutic targets

Latest insights into the global epidemiological features, screening, early diagnosis and prognosis prediction of esophageal squamous cell carcinoma

As a highly invasive carcinoma, esophageal cancer (EC) was the eighth most prevalent malignancy and the sixth leading cause of cancer-related death worldwide in 2020. Esophageal squamous cell carcinoma (ESCC) is the major histological subtype of EC, and its incidence and mortality rates are decreasing globally. Due to the lack of specific early symptoms, ESCC patients are usually diagnosed with advanced-stage disease with a poor prognosis, and the incidence and mortality rates are still high in many countries, especially in China. Therefore, enormous challenges still exist in the management of ESCC, and novel strategies are urgently needed to further decrease the incidence and mortality rates of ESCC. Although the key molecular mechanisms underlying ESCC pathogenesis have not been fully elucidated, certain promising biomarkers are being investigated to facilitate clinical decision-making. With the advent and advancement of high-throughput technologies, such as genomics, proteomics and metabolomics, valuable biomarkers with high sensitivity, specificity and stability could be identified for ESCC. Herein, we aimed to determine the epidemiological features of ESCC in different regions of the world, especially in China, and focused on novel molecular biomarkers associated with ESCC screening, early diagnosis and prognosis prediction.

TMEM16A ion channel: A novel target for cancer treatment

Cancer draws attention owing to the high morbidity and mortality. It is urgent to develop safe and effective cancer therapeutics. The calcium-activated chloride channel TMEM16A is widely distributed in various tissues and regulates physiological functions. TMEM16A is abnormally expressed in several cancers and associate with tumorigenesis, metastasis, and prognosis. Knockdown or inhibition of TMEM16A in cancer cells significantly inhibits cancer development. Therefore, TMEM16A is considered as a biomarker and therapeutic target for some cancers. This work reviews the cancers associated with TMEM16A. Then, the molecular mechanism of TMEM16A overexpression in cancer was analyzed, and the possible signal transduction mechanism of TMEM16A regulating cancer development was summarized. Finally, TMEM16A inhibitors with anticancer effect and their anticancer mechanism were concluded. We hope to provide new ideas for pharmacological studies on TMEM16A in cancer.

Prognostic Significance of CDK6 Amplification in Esophageal Squamous Cell Carcinoma

Dysregulation of CDK6 plays crucial roles in the carcinogenesis of many kinds of human malignancies. However, the role of CDK6 in esophageal squamous cell carcinoma (ESCC) is not well known. We investigated the frequency and prognostic value of CDK6 amplification to improve the risk stratification in patients with ESCC. Pan-cancer analysis of CDK6 was conducted on The Cancer Genome Atlas (TCGA), Genotype-Tissue Expression (GTEx) and Gene Expression Omnibus (GEO) databases. CDK6 amplification was detected in 502 ESCC samples by Fluorescence in situ hybridization (FISH) through tissue microarrays (TMA). Pan-cancer analysis revealed that CDK6 mRNA level was much higher in multiple kinds of cancers and higher CDK6 mRNA level indicated a better prognosis in ESCC. In this study, CDK6 amplification was detected in 27.5% (138/502) of patients with ESCC. CDK6 amplification was significantly correlated with tumor size (p = 0.044). Patients with CDK6 amplification tended to have a longer disease-free survival (DFS) (p = 0.228) and overall survival (OS) (p = 0.200) compared with patients without CDK6 amplification but of no significance. When further divided into I-II and III-IV stage, CDK6 amplification was significantly associated with longer DFS and OS in III-IV stage group (DFS, p = 0.036; OS, p = 0.022) rather than in I-II stage group (DFS, p = 0.776; OS, p = 0.611). On univariate and multivariate analysis of Cox hazard model, differentiation, vessel invasion, nerve invasion, invasive depth, lymph node metastasis and clinical stage were significantly associated with DFS and OS. Moreover, invasion depth was an independent factor for ESCC prognosis. Taken together, for ESCC patients in III-IV stage, CDK6 amplification indicated a better prognosis.

Involvement of Metabolites and Non-coding RNAs in Diseases

Non-coding RNAs have a role in gene regulation and cellular metabolism control. Metabolism produces metabolites which are small molecules formed during the metabolic process. So far, a direct relationship between metabolites and genes is not fully established; however, pseudogenes and their progenitor genes regulate health and disease states. Other non-coding RNAs also contribute to this regulation at different cellular processes. Accumulation and depletion of metabolites accompany the dynamic equilibrium of health and disease state. In this study, metabolites, their roles in the cell, and the link between metabolites and non-coding RNAs are discussed.

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-LET Regulates Glycolysis and Glutamine Decomposition of Esophageal Squamous Cell Carcinoma Through miR-93-5p/miR-106b-5p/SOCS4

Background

Dysregulated non-coding RNAs exhibit critical functions in various cancers. Nonetheless, the levels and corresponding functions of cirCSNX14 in esophageal squamous cell carcinoma (ESCC) yet remain to be elucidated.

Methods

Initially, the aberrant low levels of lncRNA-LET within ESCC tissues are validated via qRT-PCR observations. Moreover, the effects of lncRNA-LET upregulation on cell proliferation in vitro are determined. In addition, a series of assays determining the mechanistic views related to metabolism is conducted. Furthermore, the effects of lncRNA-LET in affecting tumor growth are investigated in vivo in a mouse model. Moreover, the interactions between lncRNA-LET and its networks are predicted and determined by RNA immunoprecipitation-assisted qRT-PCR as well as luciferase reporter assays.

Results

The downregulation of lncRNA-LET is correlated to the poor prognosis of ESCC patients. Moreover, the upregulated expression of lncRNA-LET could have reduced the cell viability. In vivo tumor inhibition efficacy assays showed that an increase of lncRNA-LET presented excellent inhibitory effects on cancer proliferation as reflected by tumor weight and volume in mice. Finally, the mechanistic views regarding the effects of miR-106b-5p or miR-93-5p and SOCS4 on ESCC are related to the feedback of lncRNA-LET.

Conclusion

Collectively, this study suggested that lncRNA-LET miR-93-5p or the miR-106b-5p-SOCS4 axis may provide great potential in establishing ESCC therapy.

CPEB3 overexpression caused by miR-106b-5p inhibition inhibits esophageal carcinoma in-vitro progression and metastasis

This study investigates the role of CPEB3 in esophageal cancer (EC) progression. The prognosis of EC patients was shown by survival analysis. CPEB3-targeting microRNAs were predicted by bioinformatics tools and further validated by dual-luciferase assay and RNA immunoprecipitation. CPEB3 expression in EC cell lines and EC tissues was analyzed by quantitative reverse transcription PCR. The viabilities of KYSE150 and EC9706 cells were measured by MTT and Cell Counting Kit-8 assays. The migration, invasion and tube formation of KYSE150 and EC9706 cells were examined by wound healing, Transwell and tube formation assay, respectively. E-cadherin, N-cadherin, fibronectin, vimentin and vascular endothelial growth factor (VEGF), epidermal growth factor receptor (EGFR) [and phosphorylation (p)] and STAT3 levels (and phosphorylation) in KYSE150 and EC9706 cells were determined by western blot analysis or quantitative reverse transcription PCR. In addition, a xenograft tumor model was established through subcutaneously implanting KYSE150 and EC9706 cells transfected with Lv-CPEB3 or Lv-control viruses. CPEB3 expression was downregulated in EC cells and tissues, and its overexpression inhibited viability, migration, invasion and the expressions of N-cadherin, fibronectin, vimentin and VEGF, EGFR, p-EGFR and p-STAT3 levels in KYSE150 cells, but promoted E-cadherin expression. Small interfering RNA (siRNA)-CPEB3 inversely affected these phenotypes and gene expressions in EC9706 cells. miR-106b-5p targeted CPEB3 and negatively regulated CPEB3 expression. miR-106b-5p mimics reversed the effect of CPEB3 overexpression on KYSE150 cells, and miR-106b-5p inhibitor reversed the effect of siRNA-CPEB3 on EC9706 cells. In mice, tumor volumes, weights and Ki-67 expression were lower in mice treated with Lv-CPEB3 than that with Lv-control. CPEB3 overexpressed by miR-106b-5p inhibition suppressed EC progression involved in EGFR and STAT3 signaling.

DNA methyltransferase 3 beta regulates promoter methylation of microRNA-149 to augment esophageal squamous cell carcinoma development through the ring finger protein 2/Wnt/β-catenin axis

Esophageal squamous cell carcinoma (ESCC) is an aggressive form of human squamous cell carcinomas with extremely aggressive pathological features. This study explores the functions of microRNA-149 (miR-149) and its interacted molecules in ESCC. The ESCC-related miRNA and messenger RNA (mRNA) datasets were applied to identify aberrantly expressed genes in ESCC. Forty-two patients with ESCC were included and their tissue samples were collected. miR-149 was poorly expressed whereas DNA methyltransferase 3 beta (DNMT3B) and ring finger protein 2 (RNF2) were abundantly expressed in ESCC tumor samples. Overexpression of miR-149 suppressed growth and invasiveness of ESCC cells in vitro and in vivo. DNMT3B bound to the promoter region of miR-149 to trigger its promoter methylation and downregulation. RNF2 mRNA was a target of miR-149. RNF2 overexpression blocked the inhibitory effect of miR-149 on ESCC cell growth. RNF2 activated the Wnt/β-catenin pathway to promote ESCC development. In conclusion, this study found that DNMT3B downregulates miR-149 level through methylation modification of the miR-149 promoter, while miR-149 suppresses RNF2 expression and inactivates the Wnt/β-catenin pathway to suppress growth of ESCC cells.

A scoping review of artificial intelligence applications in thoracic surgery

OBJECTIVES

Machine learning (ML) has great potential, but there are few examples of its implementation improving outcomes. The thoracic surgeon must be aware of pertinent ML literature and how to evaluate this field for the safe translation to patient care. This scoping review provides an introduction to ML applications specific to the thoracic surgeon. We review current applications, limitations and future directions.

METHODS

A search of the PubMed database was conducted with inclusion requirements being the use of an ML algorithm to analyse patient information relevant to a thoracic surgeon and contain sufficient details on the data used, ML methods and results. Twenty-two papers met the criteria and were reviewed using a methodological quality rubric.

RESULTS

ML demonstrated enhanced preoperative test accuracy, earlier pathological diagnosis, therapies to maximize survival and predictions of adverse events and survival after surgery. However, only 4 performed external validation. One demonstrated improved patient outcomes, nearly all failed to perform model calibration and one addressed fairness and bias with most not generalizable to different populations. There was a considerable variation to allow for reproducibility.

CONCLUSIONS

There is promise but also challenges for ML in thoracic surgery. The transparency of data and algorithm design and the systemic bias on which models are dependent remain issues to be addressed. Although there has yet to be widespread use in thoracic surgery, it is essential thoracic surgeons be at the forefront of the eventual safe introduction of ML to the clinic and operating room.

Mechanism of methyltransferase like 3 in epithelial-mesenchymal transition process, invasion, and metastasis in esophageal cancer

Methyltransferase like 3 (METTL3) has been identified to serve as a definitive inducer in cancer progression. This study sought to analyze the regulatory mechanism of METTL3 in epithelial-mesenchymal transition (EMT), invasion, and metastasis in esophageal cancer (ESCA). The METTL3 expressions in cancer tissues and cells were detected with extensive analysis of its correlation with clinical baseline data. The cells were transfected with sh-RNA-METTL3 and microRNA (miR)-20a-5p mimic, followed by evaluation of invasion, migration, and EMT. The N6-methyladenosine (m6A) level and enrichment of DiGeorge Critical Region 8 (DGCR8) and m6A were observed. The binding relationship between miR-20a-5p and Nuclear Factor I-C (NFIC) was verified, followed by Pearson correlation analysis. A subcutaneous tumor formation assay was conducted prior to observation of lung metastases. Our results revealed that METTL3 was highly expressed in ESCA patients and associated with severe lymph node involvement and distant metastasis. METTL3 downregulation radically inhibited the invasiveness, migration, and EMT. METTL3 elevated the miR-20a-5p expression via improving m6A modification. METTL3 inhibition downregulated the miR-20a-5p expression. Moreover, miR-20a-5p upregulation facilitated ESCA cell invasiveness and migration by targeting NFIC transcription. METTL3 inhibition suppressed tumor growth and lung metastasis in vivo. Overall, METTL3 promoted m6A modification and the binding of DGCR8 to miR-20a-5p to further elevate the miR-20a-5p expression and inhibit NFIC transcription, thus promoting EMT, invasion and migration.

Identification of miRNAs and genes for predicting Barrett's esophagus progressing to esophageal adenocarcinoma using miRNA-mRNA integrated analysis

Barrett's esophagus (BE) is defined as any metaplastic columnar epithelium in the distal esophagus, which predisposes to esophageal adenocarcinoma (EAC). Yet, the mechanism through which BE develops to EAC still remain unclear. Moreover, the miRNA-mRNA regulatory network in distinguishing BE from EAC still remains poorly understood. To identify differentially expressed miRNAs (DEMs) and genes (DEGs) between EAC and BE from tissue samples, gene expression microarray datasets GSE13898, GSE26886, GSE1420 and miRNA microarray datasets GSE16456, GSE20099 were downloaded from Gene Expression Omnibus (GEO) database. GEO2R was used to screen the DEMs and DEGs. Pathway and functional enrichment analysis were performed by DAVID database. The protein-protein interaction (PPI) network was constructed by STRING and been visualized by Cytoscape software. Finnal, survival analysis was performed basing TCGA database. A total of 21 DEMs were identified. The enriched functions and pathways analysis inclued Epstein-Barr virus infection, herpesvirus infection and TRP channels. GART, TNFSF11, GTSE1, NEK2, ICAM1, PSMD12, CTNNB1, CDH1, PSEN1, IL1B, CTNND1, JAG1, CDH17, ITCH, CALM1 and ITGA6 were considered as the hub-genes. Hsa-miR-143 and hsa-miR-133b were the highest connectivity target gene. JAG1 was predicted as the largest number of target miRNAs. The expression of hsa-miR-181d, hsa-miR-185, hsa-miR-15b, hsa-miR-214 and hsa-miR-496 was significantly different between normal tissue and EAC. CDH1, GART, GTSE1, NEK2 and hsa-miR-496, hsa-miR-214, hsa-miR-15b were found to be correlated with survival.

Effects of dietary zinc deficiency on esophageal squamous cell proliferation and the mechanisms involved

BACKGROUND

Dietary zinc deficiency has been shown to be associated with the development of esophageal cancer in humans, but the exact mechanism of action is not known

AIM

To observe the effects of dietary zinc deficiency on esophageal squamous cell proliferation.

METHODS

Thirty C57BL/6 mice were randomly divided into three groups: A zinc-sufficient (ZS) group, zinc-deficient (ZD) group, and zinc-replenished (ZR) group. For weeks 1–10, zinc levels in the mice diets were 30.66–30.89 mg/kg in the ZS group and 0.66–0.89 mg/kg in the ZD and ZR groups. During weeks 10–12, the ZR group was switched to the ZS diet; the other two groups had no changes in their diets. Changes in body weight, serum, and esophageal tissue zinc concentrations were assessed as well as differences in the expression of proliferating cell nuclear antigen (PCNA), mitogen-activated protein kinase p38 (p38MAPK), nuclear factor kappa B (NF-κB) p105, NF-κB p65, and cyclooxygenase (COX)-2 proteins in the esophageal mucosa.

RESULTS

The body weight and zinc concentration in the serum and esophageal mucosa were significantly lower in the ZD and ZR groups than in the ZS group (P < 0.05). In ZD mice, there was a marked proliferation of basal cells in the esophageal mucosa, resulting in a disturbance in the arrangement of basal cells in layers 2–4, a thickening of the squamous layer, and a significant increase in the expression of the above-mentioned five proteins involved in proliferation and inflammation in the esophageal mucosa. Two weeks after switching to the ZS diet, the serum zinc concentration in the ZR group increased, and the expression of PCNA, NF-κB p105, and COX-2 decreased, but the concentration of zinc in the esophageal mucosa and the structure of the esophageal mucosa did not display any significant changes

CONCLUSION

The ZD diet decreased the growth rate and promoted the proliferation of esophageal squamous cells in mice. The mechanism of proliferation was related to the induced overexpression of COX-2, P38, PCNA, and NF-κB (p105 and p65), and the ZR diet reduced the expression of PCNA, NF-κB p105, and COX-2, thereby reversing this process.

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Prognostic value of microRNA-4521 in non-small cell lung cancer and its regulatory effect on tumor progression

Background

Non-small cell lung cancer (NSCLC) is a malignant tumor with the highest mortality rate in our country. It has been found in many studies that microRNA-4521 (miR-4521) is abnormally expressed and plays a role in clear cell renal cell carcinoma and other cancers.

Objective

The purpose of this study was to explore the relationship between miR-4521 expression and clinical prognosis, as well as its influence on cell biological behavior.

Methods

The expression differences of miR-4521 in NSCLC tissues and cells were examined by qRT-PCR technology. Kaplan–Meier survival analysis and Cox regression analysis were used to analyze the clinical information and survival status of patients to explore the relationship. Using the vitro cell MTT assay, Transwell assay, and western-blot analysis, the effects of miR-4521 on cell proliferation, migration, and invasion were analyzed.

Results

The expression of miR-4521 in NSCLC tissues and cells was significantly downregulated. miR-4521 can be used as an independent prognostic factor. The survival rate of the miR-4521 low expression group was lower, which was significantly related to poor prognosis. In addition, the low expression of miR-4521 significantly promoted cell proliferation, migration, and invasion with highly expressed related protein levels. FOXM1 might be a direct target of miR-4521.

Conclusion

The results of this study showed that the low expression of miR-4521 indicated the poor prognosis of NSCLC and promoted cell proliferation, migration, and invasion by targeting FOXM1.

Roles of microRNAs in tumorigenesis and metastasis of esophageal squamous cell carcinoma

Esophageal squamous cell carcinoma (ESCC) is the major subtype of esophageal cancer that is prevalent in Eastern Asia. Despite recent advances in therapy, the outcome of ESCC patients is still dismal. MicroRNAs (miRNAs) are non-coding RNAs which can negatively modulate gene expression at the post-transcriptional level. The involvement and roles of miRNAs have become one of the hot topics of cancer research in recent years. In ESCC, genetic variations within miRNA coding genes were found to have distinct epidemiological significance in different populations. Dysregulated expression of several miRNAs was reported to be associated with therapeutic response. Functionally, miRNAs can act either in an oncogenic or a tumor-suppressive manner during tumorigenesis of ESCC by interrupting signaling pathways associated with cell proliferation, metabolism, cancer stemness, and resistance to chemo- or radiotherapy. Moreover, miRNAs modulate metastasis of ESCC by targeting genes that regulate cytoskeleton dynamics, extracellular matrix remodeling, epithelial-mesenchymal transition, and tumor microenvironment. Most importantly, mounting evidence suggests that inhibiting oncogenic miRNAs or restoring the loss of tumor-suppressive miRNAs has therapeutic potential in the treatment of ESCC. Here, we review and discuss recent studies on the significance, biological functions, and therapeutic potential of miRNAs in tumorigenesis and metastasis of ESCC.

Overexpression of microRNA-19a-3p promotes lymph node metastasis of esophageal squamous cell carcinoma via the RAC1/CDC42-PAK1 pathway

BACKGROUND

A tendency towards extensive regional lymph node metastasis (LNM) is a typical clinical characteristic of esophageal squamous cell carcinoma (ESCC). Up-regulated microRNA (miR)-19a-3p was verified as a predictor of LNM in ESCC in previous microarray analyses, but the underlying mechanisms remain unclear. Here, in vitro experiments were performed to confirm the effect of miR-19a-3p on promoting LNM and to explore the underlying mechanisms.

METHODS

KYSE-150 and TE-1 cell lines were transfected with lentiviral vectors to inhibit miR-19a-3p (LV-miR-19a-3p-inhibition), and cell proliferation, invasion, and migration were assessed. Target genes of miR-19a-3p were identified by sequencing analysis and quantitative reverse transcription PCR (qRT-PCR); Western blotting was performed to confirm targets and explore the potential mechanisms underlying the effect of miR-19a-3p on LNM.

RESULTS

miR-19a-3p had no effect on ESCC cell proliferation, whereas miR-19a-3p overexpression promoted the invasion and migration of ESCC cells. qRT-PCR verification and western blot analysis showed that LV-miR-19a-3p-inhibition downregulated cell division cycle 42 (CDC42), Rac family small GTPase 1 (RAC1), and p21 activated kinase 1 (PAK1).

CONCLUSIONS

Overexpression of miR-19a-3p increased the invasion and migration of ESCC cells via the RAC1/CDC42-PAK1 pathway, suggesting that this pathway mediates the effect of miR-19a-3p on promoting LNM in ESCC.

circ_NRIP1 is oncogenic in malignant development of esophageal squamous cell carcinoma (ESCC) via miR-595/SEMA4D axis and PI3K/AKT pathway

BACKGROUND

The hsa_circ_0004771 derived from NRIP1 (called circ_NRIP1) is a recently identified oncogenic circRNA. Here, we intended to investigate the role and mechanism of circ_NRIP1 in esophageal squamous cell carcinoma (ESCC), a prevalent and aggressive type of esophageal cancer.

METHODS

Expression of circ_NRIP1, miRNA-595-5p (miR-595) and semaphorin 4D (SEMA4D) was detected by RT-qPCR and western blotting. Cell growth was assessed by colony formation assay, MTS assay, flow cytometry, and xenograft experiment; migration and invasion were evaluated by transwell assay and western blotting. Dual-luciferase reporter assay identified the relationship among circ_NRIP1, miR-595 and SEMA4D. Western blotting measured phosphatidylinositol-3-hydroxykinase (PI3K)/AKT pathway-related proteins.

RESULTS

Expression of circ_NRIP1 was upregulated in ESCC tissues and cells. Knockdown of circ_NRIP1 could enhance apoptosis rate and E-cadherin expression, but suppress colony formation, cell viability, migration, invasion, and snail expression in KYSE30 and KYSE450 cells, as well as retarded tumor growth in mice. The suppressive role of circ_NRIP1 knockdown in cell growth, migration and invasion in vitro was abated by blocking miR-595; meanwhile, miR-595 overexpression elicited similar anti-tumor role in KYSE30 and KYSE450 cells, which was abrogated by restoring SEMA4D. Notably, circ_NRIP1 was a sponge for miR-595, and SEMA4D was a target of miR-595. Besides, PI3K/AKT signal was inhibited by circ_NRIP1 knockdown and/or miR-595 overexpression via indirectly or directly regulating SEMA4D.

CONCLUSION

circ_NRIP1 functioned as an oncogene in ESCC, and modulated ESCC cell growth, migration and invasion both in vitro and in vivo via targeting miR-595/SEMA4D axis and inhibiting PI3K/AKT signaling pathway.

Prognostic value of microRNA-378 in esophageal cancer and its regulatory effect on tumor progression

The incidence and mortality rates of esophageal squamous cell carcinoma (ESCC) are high in China, which has increased the clinical and economic burden. The present study aimed to investigate the role of microRNA (miRNA/miR)-378 in ESCC. Reverse transcription-quantitative polymerase chain reaction analysis was performed to detect miR-378 expression in ESCC tissues and cell lines. Survival analysis was performed using the Kaplan-Meier method, while Cox regression analysis was performed to determine the prognostic value of miR-378 in ESCC. miR-378 mimic and miR-378 inhibitor was transfected into ESCC cells to overexpress or knockdown miR-378 expression levels in ESCC cells. The Cell Counting Kit-8 assay was performed to assess the proliferative ability of ESCC cells, while the Transwell assay was conducted to assess the effect of miR-378 on the migratory and invasive abilities of ESCC cells. The results demonstrated that miR-378 displayed significantly lower expression both in ESCC cells and tissues by comparison with those in normal cells and adjacent tissues. In addition, patients with low miR-378 expression had a worse prognosis and a shorter overall survival time than those with high miR-378 expression. Furthermore, low miR-378 expression promoted ESCC cell proliferation, migration and invasion. Taken together, the results of the present study suggest that miR-378 may act as a tumor suppressor in the occurrence and development of ESCC.

CDK4 Amplification in Esophageal Squamous Cell Carcinoma Associated With Better Patient Outcome

In the present study, we aimed to investigate the clinical and prognostic values of CDK4 amplification and improve the risk stratification in patients with esophageal squamous cell carcinoma. CDK4 amplification was analyzed by fluorescence in situ hybridization using tissue microarray consisting of representative tissues of 520 patients with esophageal squamous cell carcinoma, and its correlation with clinicopathological features and clinical outcomes were evaluated. CDK4 amplification was found in 8.5% (44/520) of patients with esophageal squamous cell carcinoma. CDK4 amplification was negatively correlated with disease progression (P = 0.003) and death (P = 0.006). Patients with CDK4 amplification showed a significantly better disease-free survival (P = 0.016) and overall survival (P = 0.023) compared with those patients without CDK4 amplification. When patients were further stratified into I–II stage groups and III–IV stage groups, CDK4 amplification was significantly associated with both better disease-free survival (P = 0.023) and overall survival (P = 0.025) in the I–II stage group rather than the III–IV stage group. On univariate and multivariate analysis, invasive depth and CDK4 amplification were associated with disease-free survival and overall survival. Taken together, CDK4 amplification was identified as an independent prognostic factor for survival, which could be incorporated into the tumor–node–metastasis staging system to refine risk stratification of patients with esophageal squamous cell carcinoma.

The predictive value of microRNAs for pathological response after neoadjuvant treatment in esophageal squamous cell carcinoma: a systematic review

Neoadjuvant treatment followed by esophagectomy has been the standard strategy for resectable locally advanced esophageal squamous cell carcinoma (ESCC). Pathological response after neoadjuvant treatment is of vital importance in the determination of long-term survival. Due to the involvement of microRNAs (miRNAs) in ESCC, some studies have proposed miRNA models to predict the pathological response. We aimed to summarize current studies on the predictive value of the miRNA models. We searched the relevant studies on PubMed, Web of Science and Cochrane Library up to February 14, 2020, using the following search term: (esophageal OR esophagus OR oesophageal OR oesophagus) AND (miR OR miRNA OR microRNA) AND (neoadjuvant OR preoperative OR induction). The initial search retrieved 206 studies. We briefly summarized the involvement of miRNAs in the origin, development and chemo- and radioresistance in ESCC. Then, 9 studies were enrolled in the systematic review. A great heterogeneity was observed across these studies. Of the 6 studies with diagnostic tests, the area under curve varied a lot. Although much evidence demonstrated the correlation between miRNAs and pathological response after in ESCC, the current studies has not established any promising models. A well-designed prospective study is essential to investigate the potential predictive models for pathological response after neoadjuvant treatment in ESCC.

The Prognostic Value and Mechanisms of TMEM16A in Human Cancer

As a calcium ion-dependent chloride channel transmembrane protein 16A (TMEM16A) locates on the cell membrane. Numerous research results have shown that TMEM16A is abnormally expressed in many cancers. Mechanically, TMEM16A participates in cancer proliferation and migration by affecting the MAPK and CAMK signaling pathways. Additionally, it is well documented that TMEM16A exerts a regulative impact on the hyperplasia of cancer cells by interacting with EGFR in head and neck squamous cell carcinoma (HNSCC), an epithelial growth factor receptor in head and neck squamous cell carcinoma respectively. Meanwhile, as an EGFR activator, TMEM16A is considered as an oncogene or a tumor-promoting factor. More and more experimental data showed that down-regulation of TMEM16A or gene targeted therapy may be an effective treatment for cancer. This review summarized its role in various cancers and research advances related to its clinical application included treatment and diagnosis.

Circulating microRNAs: Biomarkers of disease

MicroRNAs are a class of endogenous noncoding single-stranded RNA molecules with approximately 20-24 nucleotides and are associated with a broad range of biological processes. Researchers found that microRNAs are abundant in tissues, and more importantly, there are also trace circulating microRNAs that exist in biological fluids. In recent years, circulating microRNAs had emerged as promising diagnostic and prognostic biomarkers for the noninvasive detection of diseases with high specificity and sensitivity. More importantly, specific microRNA expression signatures reflect not only the existence of early-stage diseases but also the dynamic development of advanced-stage diseases, disease prognosis prediction, and drug resistance. To date, an increasing number of potential miRNA biomarkers have been reported, but their practical application prospects are still unclear. Therefore, microRNAs, as potential diagnostic and prognostic biomarkers in a variety of diseases, need to be updated, as they are of great importance in the diagnosis, prognosis and prediction of therapeutic responses. In this review, we summary our current understanding of microRNAs as potential biomarkers in the major diseases (e.g., cancers and cardio-cerebrovascular diseases), which provide the basis for the design of diagnosis and treatment plan and the improvement of the cure rate.

SphK1-targeted miR-6784 inhibits functions of skin squamous cell carcinoma cells

Sphingosine kinase 1 (SphK1) is overexpressed in skin squamous cell carcinoma (SCC). It has emerged as a novel therapeutic oncotarget. The current study identified a novel SphK1-targeting microRNA, microRNA-6784 (miR-6784). Here, we show that miR-6784 is located at the cytoplasm of A431 skin SCC cells. It directly binds to SphK1 mRNA. Ectopic overexpression of miR-6784 inhibited SphK1 3’-untranslated region (UTR) luciferase activity and downregulated its expression. Moreover, miR-6784 overexpression caused ceramide accumulation in skin SCC cells. Functional studies in established (A431 and SCC9) and primary skin SCC cells revealed that miR-6784 overexpression inhibited cell viability, proliferation, migration, and invasion. It also simultaneously provoked apoptosis activation. Conversely, miR-6784 silencing by antagomiR-6784 induced SphK1 elevation and augmented A431 cell proliferation, migration, and invasion. miR-6784 overexpression-induced anti-A431 cell activity was inhibited by the expression of an UTR-null SphK1 construct. CRISPR/Cas9-induced SphK1 knockout inhibited A431 cell growth. Importantly, miR-6784 was completely ineffective when treating SphK1-knockout A431 cells. Collectively, miR-6784 silences SphK1 and inhibits skin SCC cell progression.

Upregulation of miR-1269 Contributes to the Progression of Esophageal Squamous Cell Cancer Cells and Is Associated With Poor Prognosis

Background:

MicroRNA-1269 (miR-1269) has been identified upregulated in several cancers, as well as in esophageal cancer. In the present study, we investigated the clinical prognostic significance and potential functional role of miR-1269 in esophageal squamous cell carcinoma (ESCC).

Methods:

A total of 107 ESCC patients who underwent surgical resection were enrolled in this study. miR-1269 expression was measured using quantitative real-time PCR (qRT-PCR). Kaplan-Meier method and multivariate Cox regression analysis were used to explore the prognostic significance of miR-1269. CCK-8 assays and Transwell assays were used to investigate the effects of miR-1269 on cell proliferation, migration, and invasion. The direct association between miR-1269 and SOX6 was evaluated using a dual-luciferase reporter assay.

Results:

The expression of miR-1269 was significantly upregulated in ESCC tissues and cell lines compared with adjacent normal tissues and esophageal epithelial cell line, respectively. What’s more, the upregulation of miR-1269 was associated with positive lymph node metastasis and advanced TNM stage. ESCC patients with high miR-1269 expression had shorter overall survival than those with low miR-1269 expression levels. Compared with the control group, overexpression of miR-1269 promoted cell proliferation, migration, and invasion, while knockdown of miR-1269 inhibited cell proliferation, migration, and invasion. SOX6 was a direct target of miR-1269.

Conclusion:

These results suggest that miR-1269 plays an important role in the progression of ESCC by targeting SOX6 and may be a potential prognostic biomarker and the miR-1269/SOX6 axis may be a therapeutic target for the patient with ESCC.

HCG11 up-regulation induced by ELK4 suppressed proliferation in vestibular schwannoma by targeting miR-620/ELK4

Background

Vestibular schwannoma (VS) is a kind of benign tumor deriving from the acoustic nerve sheath. Substantial long non-coding RNAs (lncRNAs) were illustrated to have crucial roles in multiple cancers. However, few lncRNAs were elucidated in VS.

Methods

HCG11, miR-620 and ELK4 expression were tested by RT-qPCR. Gain-of-function experiments were conducted to confirm the effect of HCG11 on VS.

Results

HCG11 possessed a low expression in VS cell lines. Overexpression of HCG11 repressed cell proliferation but accelerated apoptosis of VS cells. Moreover, we identified ELK4 stimulated the transcription of HCG11 and their affinity was verified by ChIP assays. MiR-620 was chosen to be a target of HCG11 and it was tested to have a high expression in VS cell lines. Moreover, depletion of miR-620 could inhibit cell proliferative ability while fostering apoptosis rate of VS cells. ELK4 was low expressed in VS cell lines and knockdown of ELK4 could rescue the effects made by HCG11 overexpression on progression of VS.

Conclusions

HCG11 could inhibit the growth of VS by targeting miR-620/ELK4 in VS cells. HCG11 was a novel therapeutic target for VS treatment.

Emerging roles of MiR-133a in human cancers

MicroRNAs (miRNAs) can post-transcriptionally regulate the expression of cancer-relevant genes via binding to the 3'-untranslated region (3'-UTR) of the target mRNAs. MiR-133a, as a miRNA, participate in tumorigenesis, progression, autophagy and drug-resistance in various malignancies. Based on the recent insights, we discuss the functions of miR-133a in physiological and pathological processes and its potential effects on cancer diagnosis, prognosis and therapy.

MiR-624-3p Promotes Esophageal Squamous Cell Carcinoma Progression via Targeting Phosphatase and Tensin Homologue

The emerging role of miRNA as regulators in esophageal squamous cell carcinoma (ESCC) progression has aroused great attention recently. In this study, the effects of miR-624-3p in ESCC progression were explored through cell proliferation, colony formation, cell cycle, and apoptosis analyses. Results showed that increased expression of miR-624-3p enhanced cancer cell viability, proliferation, migration, and invasion but inhibited apoptosis in ESCC. Moreover, luciferase reporter assay demonstrated that miR-624-3p bound to the 3'-untranslated region of phosphatase and tensin homologue (PTEN). Further study showed that miR-624-3p exerted its tumor promoting role through targeting PTEN. Taken together, these results elucidate the regulatory role of miR-624-3p in ESCC progression, shedding light on its possible clinical application in ESCC treatment.

Exosome-Encapsulated MicroRNA-21 from Esophageal Squamous Cell Carcinoma Cells Enhances Angiogenesis of Human Umbilical Venous Endothelial Cells by Targeting SPRY1

Objective

Esophageal squamous cell carcinoma (ESCC) persists among the most prevalent cancers worldwide. Angiogenesis represents a crucial element necessitated for tumor growth and metastasis in ESCC. In this study, we aimed to study the effect of microRNA (miR)-21 on angiogenesis in ESCC and its underlying mechanism.

Materials and Methods

Initially, the expression patterns of miR-21, SPRY1, and VEGF were determined in ESCC tissues and cells. The relationship between miR-21 and SPRY1 was identified using dual-luciferase reporter assay. Exosomes were subsequently isolated from the ESCC cells, followed by co-culture with the human umbilical venous endothelial cells (HUVECs). HUVEC proliferation and angiogenesis were determined by means of CCK-8, colony formation, and microtubule formation in vitro. Chicken chorioallantoic membrane (CAM) model and mouse xenograft model of ESCC cells were established to substantiate the function of miR-21 corresponding to the angiogenesis and tumor growth of ESCC, followed by microvascular density (MVD) evaluation.

Results

Expression patterns of miR-21 and VEGF were elevated, while the SPRY1 expression pattern was repressed in ESCC tissues and cells. The downregulation of miR-21 and exosome-derived miR-21 impeded the proliferation and angiogenesis in HUVECs. Our data revealed that miR-21 could negatively target SPRY1, and positively target VEGF. The downregulation of miR-21 could evidently encumber the angiogenesis and tumor growth of ESCC in vivo, as evidenced by the decrease in number of branches of the microvessels and MVD.

Conclusion

Collectively, ESCC cell-derived exosome containing miR-21 promotes the proliferation and angiogenesis of HUVECs via SPRY1 downregulation and VEGF upregulation.

miR-550a-3/NFIC plays a driving role in esophageal squamous cell cancer cells proliferation and metastasis partly through EMT process

In this study, the functional role of miR-550a-3 and its direct target nuclear factor IC (NFIC) in esophageal squamous cell cancer (ESCC) cells were explored. Differential expression of miR-550a-3 in ESCC tissues was acquired from TCGA database, and Kaplan-Meier method was used to determine the relationship between miR-550a-3 expression and survival time of ESCC patients. Expression level of miR-550a-3 in several ESCC cell lines was measured by qRT-PCR. Two cell lines including Eca109 and JAR were used to perform proliferation, cloning, invasion and migration experiments. Targeted relationship between miR-550a-3 and NFIC was speculated by predication software and confirmed by dual luciferase assay. Additionally, potential relationship between miR-550a-3 and NFIC was analyzed by Spearman rank correlation analysis and western blot. Rescue assays were performed to explore the function of miR-550a-3/NFIC in ESCC cells biological behaviors. Expression levels of key proteins involved in epithelial-to-mesenchymal transition (EMT) process were determined by western blot. By consulting TCGA database, we found that high expression of miR-550a-3 was positively connected with the poor prognosis of patients with ESCC. In addition, overexpression of miR-550a-3 promoted the proliferation, colony formation and metastasis of ESCC cells. Moreover, rescue assays revealed that overexpression of NFIC attenuated the promoting effects of miR-550a-3 on ESCC cells malignant behaviors. While the promoting effects of miR-550a-3 on EMT process were inhibited by NFIC. Our results illustrate the importance of miR-550a-3/NFIC in regulation of ESCC cells growth and metastasis, which could contribute to developing novel target for early diagnosis or neoteric therapeutic target for ESCC.

MicroRNA-105 plays an independent prognostic role in esophageal cancer and acts as an oncogene

BACKGROUND

Esophageal cancer is a common tumor with high mortality worldwide. In the present study, we aimed to investigate the prognostic significance and regulatory effects of miR-105 on cellular functions of esophageal cancer cells.

METHODS

The expression level of miR-105 was analyzed in esophageal cancer tissues and cell lines by qRT-PCR. Survival analysis was carried out using the Kaplan-Meier and the prognostic significance of miR-105 was analyzed with Cox regression analysis. The effects of miR-105 on cell proliferation, migration, and invasion abilities were detected with cellular experiments.

RESULTS

We found that miR-105 was significantly upregulated in esophageal cancer tissues and cell lines, compared with the control group, respectively. Moreover, overexpression of miR-105 was significantly associated with positive lymph node metastasis, advanced TNM stage, and poor overall survival. In addition, overexpression of miR-105 promoted cell proliferation, migration, and invasion in esophageal cancer cells, while downregulation of miR-105 suppressed these cellular behaviors.

CONCLUSION

Our findings indicate that a higher level of miR-105 predicts poorer prognosis in esophageal cancer patients, and miR-105 can promote esophageal cancer cell proliferation, migration, and invasion.

The Depletion of ABI3BP by MicroRNA-183 Promotes the Development of Esophageal Carcinoma

Background

Esophageal cancer (EC), as a serious threat to human life and health, is one of the most common cancers around the world. Many studies have suggested that many microRNAs are involved in tumorigenesis and progression.

Methods

To search for a novel and promising predictive therapeutic target or biomarker to achieve the goal of the early diagnosis and treatment of EC, we used the EC cell lines Eca-109 and KYSE-150 and normal human esophageal epithelial cells (HEECs) to investigate the effect of ABI3BP on EC.

Results

We found that ABI family member 3 binding protein (ABI3BP) was downregulated in EC and suppressed the proliferation, activity, migration, and invasion of EC cells. ABI3BP was downregulated by miR-183, which plays the role of an oncogene.

Conclusion

ABI3BP and miR-183 can be considered potential biomarkers for the diagnosis of patients with EC and can be effective targets for antitumor therapy.

Human umbilical cord mesenchymal stem cells-derived exosomes deliver microRNA-375 to downregulate ENAH and thus retard esophageal squamous cell carcinoma progression

Background

Exosomal microRNAs (miRNAs or miRs) from bone marrow-derived mesenchymal stem cells (UCMSCs) have emerged as promising therapeutic strategies for cancer treatment. The current study aimed to elucidate the underlying mechanism of human umbilical cord mesenchymal stem cells (hUCMSCs)-derived exosomal miR-375 in esophageal squamous cell carcinoma (ESCC).

Methods

After determining the expression of miR-375 and its putative target enabled homolog (ENAH) in ESCC tissues and cells, we tested effects of their altered expression on ESCC proliferation, invasion, migration, and tumorsphere formation was subsequently measured. Transfected hUCMSCs-derived exosomes (hUCMSCs-exo) were isolated and co-cultured with ESCC cells to measure the effects of miR-375 delivered by hUCMSCs-exo on ESCC development. Finally, we investigated the effect of miR-375 on tumor growth in vivo.

Results

The expression of miR-375 was reduced, while the expression of ENAH was elevated in ESCC. ENAH was identified as a target gene of miR-375. Elevated miR-375 or depleted ENAH expression inhibited ESCC cell proliferation, invasion, migration, tumorsphere formation, and promoted apoptosis. Moreover, miR-375 delivered by hUCMSCs-exo could suppress ESCC cell proliferation, invasion, migration, tumorsphere formation, but promoted apoptosis in vitro, as well as inhibiting tumor growth in vivo.

Conclusions

Taken together, hUCMSCs-exo can deliver miR-375 to suppress ENAH expression and subsequently inhibit the initiation and progression of ESCC.

Knockdown of circular RNA UBAP2 inhibits the malignant behaviours of esophageal squamous cell carcinoma by microRNA-422a/Rab10 axis

Esophageal squamous cell carcinoma (ESCC) is a major type of esophageal cancer, accounting for about 90% of cases. Circular RNA UBAP2 (circUBAP2) is involved in the progression of several types of cancers. However, the role of circUBAP2 in ESCC remains unclear. In the present study, circUBAP2 expression was found to be upregulated in ESCC tumour tissues. Knockdown of circUBAP2 through infection with lentiviral vector encoding shRNA targeting circUBAP2 (sh-circUBAP2) inhibited the proliferation, migration and invasion of ESCC cells. In addition, circUBAP2 significantly promoted the proliferation, migration and invasion of ESCC cells. In vivo xenograft assay demonstrated that circUBAP2 downregulation suppressed the tumour growth of ESCC. Further mechanism investigations proved that circUBAP2 exerted its role via sponging microRNA (miR)-422a, and miR-422a directly targeted Rab10 in ESCC cells. These findings suggested that circUBAP2 acted as oncogene through regulating the miR-422a/Rab10 axis in ESCC.

Regulatory networks between Polycomb complexes and non-coding RNAs in the central nervous system

High-throughput sequencing has facilitated the identification of many types of non-coding RNAs (ncRNAs) involved in diverse cellular processes. NcRNAs as epigenetic mediators play key roles in neuronal development, maintenance, and dysfunction by controlling gene expression at multiple levels. NcRNAs may not only target specific DNA or RNA for gene silence but may also directly interact with chromatin-modifying proteins like Polycomb group (PcG) proteins to drive orchestrated transcriptional programs. Recent significant progress has been made in characterizing ncRNAs and PcG proteins involved in transcriptional, post-transcriptional, and epigenetic regulation. More importantly, dysregulation of ncRNAs, PcG proteins, and interplay among them is closely associated with the pathogenesis of central nervous system (CNS) disorders. In this review, we focus on the interplay between ncRNAs and PcG proteins in the CNS and highlight the functional roles of the partnership during neural development and diseases.

miR-203 affects esophageal cancer cell proliferation, apoptosis and invasion by targeting MAP3K1

miR-203 has been indicated to be a tumor suppressor in esophageal cancer, however, the underlying molecular mechanisms by which it functions are not fully understood. The present study aimed to investigate the molecular mechanisms underlying the regulatory activities of microRNA (miR)-203 in esophageal cancer. The miR-203 mimic/inhibitor, Mitogen-Activated Protein Kinase Kinase Kinase 1 (MAP3K1) overexpression plasmid and MAP3K1 small interfering (si)RNA were transfected into TE-1 cells. miR-203 and MAP3K1 mRNA expression were detected via reverse transcription-quantitative PCR analysis, while MAP3K1 protein expression was detected via western blot analysis. Dual-luciferase reporter assay was used to determine whether MAP3K1 was a direct target of miR-203. Cell proliferation and invasion abilities were assessed via MTT and Matrigel assays, respectively. Cell apoptosis was analyzed via flow cytometry, Caspase 8/3 Assay kits and western blot analysis. The results demonstrated that MAP3K1 was a direct target of miR-203. Overexpression of MAP3K1 reversed the suppressed cell proliferation and invasion abilities induced by miR-203 mimic, as well as the inhibitory effect of miR-203 mimic on cell apoptosis. Furthermore, MAP3K1 siRNA weakened the effect of miR-203 inhibitor on cell proliferation, apoptosis and invasion.

miR-613 suppresses migration and invasion in esophageal squamous cell carcinoma via the targeting of G6PD

Esophageal squamous cell carcinoma (ESCC) is a common cancer in China and has a high mortality rate. MicroRNAs (miRs) are a family of post-transcriptional regulators, which negatively regulate target gene expression. miR-613 has been revealed to be a diagnostic and prognostic biomarker in ESCC. However, the role of miR-613 in ESCC remains unclear. In the present study, miR-613 expression was identified to be reduced in tumor tissues in comparison with corresponding adjacent normal tissues. TargetScan and a dual-luciferase reporter assay verified glucose-6-phosphate dehydrogenase (G6PD) as a direct target of miR-613. In contrast with miR-613, G6PD expression was increased in tumor tissues compared with matched healthy tissues. Furthermore, overexpression of miR-613 inhibited cell migration and invasion of Eca109 cells compared with controls, while G6PD overexpression reversed the inhibition induced by miR-613, as determined by wound healing and Transwell assays. In addition, miR-613 overexpression decreased the mRNA and protein expression of G6PD, matrix metalloproteinase (MMP)2 and MMP9, and reduced the phosphorylation of signal transducer and activator of transcription 3 (STAT3) compared with controls, while G6PD reversed the effects of miR-613. However, miR-613 and G6PD did not affect the expression of STAT3. In conclusion, the aforementioned results suggest that miR-613 targets G6PD to suppress ESCC cell migration and invasion through reduced MMP2 and MMP9 expression and inactivation of the STAT3 signaling pathway. Thus, the present study may provide a new molecular foundation for treatment of ESCC.

microRNA-mRNA network model in patients with achalasia

BACKGROUND

Achalasia is a rare idiopathic disease with a complex etio-pathogenesis still unknown. This study aimed to identify microRNA (miRNA)-mRNA regulatory networks underlying achalasia.

METHODS

The investigation was performed in tissue specimens from 11 patients and five controls using the microarray technology followed by an integrated bioinformatics analysis.

KEY RESULTS

One hundred and six miRNAs were significantly up-regulated and 64 were down-regulated in achalasia patients. The expression of the most 10 differential expressed miRNAs (miR-122-5p, miR-133a-3p, miR-504-5p, miR-187-3p, miR-133b, miR-200c-3p, miR-375, miR-200b-5p, miR-200b-3p, and miR203a) was confirmed by droplet digital PCR in an independent cohort. The interactions between the significant miRNAs and their targets uncovered 14 miRNA-mRNA interacting pairs with experimentally predicted genes (ie, FN1, ROCK2, DPYSL2), and 35 pairs with not experimentally target genes (ie, SULF1, MRVI1, PRKG1); all genes were involved in immune cell trafficking, skeletal and muscular system development, nervous system development macro-processes.

CONCLUSION & INFERENCES

The mRNA-miRNA regulatory networks described in this study provide new insights in the genetic background of the disease, suggesting further investigations in novel pathogenic mechanisms.

Roles of MicroRNAs in Esophageal Squamous Cell Carcinoma Pathogenesis

MicroRNAs (miRNAs) are 20-22 nucleotides long single-stranded noncoding RNAs. They regulate gene expression posttranscriptionally by base pairing with the complementary sequences in the 3'-untranslated region of their targeted mRNA. Aberrant expression of miRNAs leads to alterations in the expression of oncogenes and tumor suppressors, thereby affecting cellular growth, proliferation, apoptosis, motility, and invasion capacity of gastrointestinal cells, including cells of esophageal squamous cell carcinoma (ESCC). Thus, alterations in miRNAs expression associated with the pathogenesis and progression of ESCC. In addition, expression profiles of miRNAs correlated with various clinicopathological factors, including pathological stages, histological differentiation, invasion, metastasis of cancer, as well as survival rates and therapy response of patients with ESCC. Consequently, expression profiles of miRNAs could be useful as diagnostic, prognostic, and prediction biomarkers in ESCC. Herein, we describe the quantitative reverse transcriptase polymerase chain reaction (qRT-PCR) and microarray methods for detection and quantitate miRNAs in ESCC. In addition, we summarize the roles of miRNAs in ESCC pathogenesis, progression, and prognosis.

Autophagy modulators for the treatment of oral and esophageal squamous cell carcinomas

Oral squamous cell carcinomas (OSCC) and esophageal squamous cell carcinomas (ESCC) exhibit a survival rate of less than 60% and 40%, respectively. Late-stage diagnosis and lack of effective treatment strategies make both OSCC and ESCC a significant health burden. Autophagy, a lysosome-dependent catabolic process, involves the degradation of intracellular components to maintain cell homeostasis. Targeting autophagy has been highlighted as a feasible therapeutic strategy with clinical utility in cancer treatment, although its associated regulatory mechanisms remain elusive. The detection of relevant biomarkers in biological fluids has been anticipated to facilitate early diagnosis and/or prognosis for these tumors. In this context, recent studies have indicated the presence of specific proteins and small RNAs, detectable in circulating plasma and serum, as biomarkers. Interestingly, the interplay between biomarkers (eg, exosomal microRNAs) and autophagic processes could be exploited in the quest for targeted and more effective therapies for OSCC and ESCC. In this review, we give an overview of the available biomarkers and innovative targeted therapeutic strategies, including the application of autophagy modulators in OSCC and ESCC. Additionally, we provide a viewpoint on the state of the art and on future therapeutic perspectives combining the early detection of relevant biomarkers with drug discovery for the treatment of OSCC and ESCC.

MicroRNA-544 inhibits esophageal squamous cell carcinoma cell proliferation and enhances sensitivity to cisplatin by repressing E2F transcription factor 5

Esophageal squamous cell carcinoma (ESCC) is one of the most common malignancies worldwide. MicroRNA (miRNA)-544 is an important cancer-associated RNA that is downregulated in multiple types of cancer. However, the role of miR-544 in ESCC progression remains unknown. In the present study, miR-544 expression level was determined via RT-qPCR in 30 pairs of ESCC and adjacent normal tissues and in a panel of ESCC cell lines. Cell proliferation and cell apoptosis were assessed by MTT and flow cytometry assays. Luciferase reporter assay and western blot analysis were conducted to verify E2F transcription factor 5 (E2F5), an oncogene in ESCC, as a novel target gene of miR-544. The results illustrated that miR-544 is frequently downregulated in ESCC tissues and cell lines. Overexpression of miR-544 in ESCC cells resulted in decreased cell proliferation and increased cell apoptosis. Thus, E2F5 was identified as a target of miR-544, and its expression was negatively correlated with miR-544 expression in clinical ESCC tissues. More importantly, overexpression of miR-544 led to increased sensitivity of ESCC cells to cisplatin, an anticancer drug. Overall, these findings indicate that miR-544 serves as a tumor suppressor by targeting E2F5; thus, miR-544 may be a therapeutic target for the treatment of ESCC.

MicroRNA-652 inhibits the biological characteristics of esophageal squamous cell carcinoma by directly targeting fibroblast growth factor receptor 1

Numerous studies have demonstrated that microRNAs (miRNAs) are dysregulated in esophageal squamous cell carcinoma (ESCC). Changes in miRNA expression may be associated with ESCC formation and progression. Therefore, the identification of ESCC-associated miRNAs may facilitate the development of effective therapeutic approaches for patients with ESCC. Recently, miRNA-652 (miR-652) was recognized as a cancer-associated miRNA in a number of different types of cancer. However, the expression status and roles of miR-652 in ESCC as well as the molecular mechanisms modulated or altered by it remain largely unknown. In the present study, it was demonstrated that miR-652 was downregulated in ESCC tissues and cell lines. Functional assays showed that upregulation of miR-652 expression decreased proliferation and invasion of ESCC cells. Mechanistically, fibroblast growth factor receptor 1 (FGFR1) was determined to be a direct target of miR-652 in ESCC cells. Additionally, FGFR1 was upregulated in ESCC tissues, and the expression of FGFR1 was inversely correlated with miR-652 expression. Furthermore, restoring FGFR1 expression abolished the suppressive effects of miR-652 overexpression on the proliferation and invasion of ESCC cells. These findings demonstrated that miR-652 inhibits the proliferation and invasion of ESCC cells by directly targeting FGFR1.

Identification of crucial miRNAs and genes in esophageal squamous cell carcinoma by miRNA-mRNA integrated analysis

Esophageal squamous cell carcinoma (ESCC) is a malignancy that severely threatens human health and carries a high incidence rate and a low 5-year survival rate. MicroRNAs (miRNAs) are commonly accepted as a key regulatory function in human cancer, but the potential regulatory mechanisms of miRNA-mRNA related to ESCC remain poorly understood.The GSE55857, GSE43732, and GSE6188 miRNA microarray datasets and the gene expression microarray datasets GSE70409, GSE29001, and GSE20347 were downloaded from Gene Expression Omnibus databases. The differentially expressed miRNAs (DEMs) and differentially expressed genes (DEGs) were obtained using GEO2R. Gene ontology (GO) and the Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis for DEGs were performed by Database for Annotation, Visualization and Integrated Discovery (DAVID). A protein-protein interaction (PPI) network and functional modules were established using the STRING database and were visualized by Cytoscape. Kaplan-Meier analysis was constructed based on The Cancer Genome Atlas (TCGA) database.In total, 26 DEMs and 280 DEGs that consisted of 96 upregulated and 184 downregulated genes were screened out. A functional enrichment analysis showed that the DEGs were mainly enriched in the ECM-receptor interaction and cytochrome P450 metabolic pathways. In addition, MMP9, PCNA, TOP2A, MMP1, AURKA, MCM2, IVL, CYP2E1, SPRR3, FOS, FLG, TGM1, and CYP2C9 were considered to be hub genes owing to high degrees in the PPI network. MiR-183-5p was with the highest connectivity target genes in hub genes. FOS was predicted to be a common target gene of the significant DEMs. Hsa-miR-9-3p, hsa-miR-34c-3p and FOS were related to patient prognosis and higher expression of the transcripts were associated with a poor OS in patients with ESCC.Our study revealed the miRNA-mediated hub genes regulatory network as a model for predicting the molecular mechanism of ESCC. This may provide novel insights for unraveling the pathogenesis of ESCC.

Jie Du Tong Ye San Prevents N-Nitrosomethylbenzylamine-Induced Esophageal Carcinogenesis via Inhibition of Inflammation and Proliferation

Jie du tong ye san (JDTYS), a traditional Chinese herbal formula, has been used for cancer adjuvant therapy in clinical use and has been shown to be effective in cancer patients. However, the mechanism of JDTYS is still unclear. Therefore, the aim of the present study is to investigate the chemopreventive effects of JDTYS for esophageal squamous cell carcinoma (ESCC) and to clarify the potential mechanism. N-nitrosomethylbenzylamine (NMBA)-induced rat esophageal carcinogenesis was used to evaluate the effect of JDTYS in vivo. Rats were treated with NMBA 3 times per week, for a total of 5 weeks. Rats in the treated groups were given JDTYS for 35 weeks. When rats were euthanized, esophageal tissue and blood were collected to evaluate the effects of JDTYS. The pathological grading of the rat esophageal preneoplastic lesions was classified and statistically analyzed. The protein levels of c-Jun and Ki67 were determined by immunohistochemistry. In addition, inflammation markers nuclear factor kappa B (NF-κB), cyclooxygenase-2 (COX-2), and the cluster of differentiation molecule 11B (CD11B) were also determined by immunohistochemistry. Moreover, the expression of COX-2 and Pentraxin 3 (PTX3) in rat serum was determined by enzyme-linked immunosorbent assay (ELISA). JDTYS could inhibit the formation of NMBA-induced esophageal preneoplastic lesions. JDTYS could downregulate the expression of proliferation related proteins Ki67 and c-Jun. Moreover, inflammation related proteins NF-κB, COX-2, and CD11B were inhibited and PTX3 was increased by JDTYS. In all, JDTYS is a promising chemopreventive formula against esophageal carcinogenesis by regulating inflammation and inhibiting cell proliferation.

β-catenin-coordinated lncRNA MALAT1 up-regulation of ZEB-1 could enhance the telomerase activity in HGF-mediated differentiation of bone marrow mesenchymal stem cells into hepatocytes

OBJECTIVE

To investigate role of β-catenin and lncRNA MALAT1/miR-217 axis to converge into the regulation of ZEB-1 in hepatocyte growth factor (HGF)-induced hepatocytes differentiated from bone marrow mesenchymal stem cells (BM-MSCs).

METHODS

BM-MSCs were isolated and HGF was used to induce the differentiation of BM-MSCs into hepatocytes. HSC-T6 cells, BRL-3 A cells and differentiated BM-MSCs were treated by lipopolysaccharide(LPS). shRNAs were used to silence β-catenin and recombinant plasmids were used to over-express ZEB1. Measurement of cell viability was conducted using MTT assay and Hoechst 33342 staining. RNA immunoprecipitation (RIP) assay was used to determine binding of miR-217-3p and MALAT1.

RESULTS

BM-MSCs successfully differentiated into hepatocytes by HGF treatment. Expression of β-catenin, ZEB-1 and TERT was up-regulated to a higher level in hepatocytes differentiated from BM-MSCs than HSC-T6 cells and BRL-3 A cells after LPS stimulation. When β-catenin was knocked down in all cell lines, expression of β-catenin, ZEB-1 and TERT was significantly decreased as well as telomerase activity. While when ZEB1 was over-expressed, expression of TERT and telomerase activity was all significantly up-regulated. In hepatocytes differentiated from BM-MSCs, miR-217 was down-regulated and lncRNA MALAT1 was up-regulated. RIP analysis showed MALAT1 was physically associated with miR-217 and might function in the regulation of ZEB-1, further enhancing the expression of TERT so as to augment telomerase activity.

CONCLUSION

We successfully used HGF to mediate differentiation of BM-MSCs into hepatocytes, and found that β-catenin-coordinated MALAT1/miR-217 axis could up-regulate expression of ZEB-1 and further enhanced the telomerase activity through regulation of TERT in BM-MSCs differentiating into hepatocytes.

MicroRNA‑21 regulates the biological behavior of esophageal squamous cell carcinoma by targeting RASA1

MicroRNA‑21 (miR‑21) has been revealed to play a crucial role in regulating the biological behavior, including proliferation, migration, invasion and metastasis in certain cancers. However, its role in esophageal squamous cell carcinoma (ESCC) has yet to be elucidated. Based on the data of GSE13937 downloaded from Gene Expression Omnibus (GEO) database, miR‑21 was revealed to be one of the top 20 differentially expressed (DE) miRNAs screened using the Morpheus online tool. RAS p21 protein activator 1 (RASA1) was predicted as the target gene of miR‑21 using the predicting software and was combined with miR‑21 using the luciferase reporter assay. Its relative expression was significantly decreased, however, miR‑21 was increased in the tumor tissues compared to the normal adjacent tissues in patients with ESCC as determined by quantitative polymerase chain reaction (q‑PCR). Furthermore, overexpression of miR‑21 (mimic) could significantly decrease the gene level of RASA1. Conversely, downregulation of miR‑21 (inhibitor) significantly increased the gene level of RASA1, while downregulation of RASA1 (siRASA1) markedly increased the gene expression of miR‑21. Notably, the expression of Snail and vimentin were significantly increased by upregulation of miR‑21 and downregulation of RASA1. Transwell results revealed that miR‑21 and RASA1 regulated proliferation, migration and invasion in ESCC cells. In an in vivo model, miR‑21 inhibitor (antagomir) could inhibit tumor growth. In conclusion, miR‑21 regulated cell proliferation, migration, invasion and tumor growth of ESCC by directly targeting RASA1, which may have been achieved via regulation of Snail and vimentin. Anti‑miR‑21 revealed an antitumor effect. Thus, it may be considered as a possible target for ESCC therapy.

Inhibitory effect of microRNA-455-5p on biological functions of esophageal squamous cell carcinoma Eca109 cells via Rab31

The aim of the present study was to examine microRNA (miRNA or miR)-455-5p expression in esophageal squamous cell carcinoma (ESCC) at the tissue and cellular levels in order to elucidate its biological roles. A total of 60 patients with ESCC were enrolled in the present study and reverse transcription-quantitative polymerase chain reaction was used to measure the expression of miR-455-5p. ESCC Eca109 cells were transfected with miR-NC, miR-455-5p mimics or inhibitor and a Cell Counting Kit-8 assay was used to assess proliferation. To investigate the migration and invasion abilities of Eca109 cells, Transwell and Matrigel assays were performed. Western blotting was employed to measure Rab31 protein expression, while a rescue assay was utilized to study the biological roles of miR-455-5p and Rab31 in Eca109 cells. To determine whether Rab31 is a direct target of miR-455-5p, a dual luciferase reporter assay was performed. The results revealed that miR-455-5p expression was decreased in ESCC tissues and was negatively correlated with metastasis and pathogenesis. In vitro overexpression of miR-455-5p inhibited the proliferation, migration and invasion of ESCC Eca109 cells. Furthermore, miR-455-5p regulated the expression of Rab31 protein in Eca109 cells. Rab31 overexpression promoted the proliferation, migration and invasion of Eca109 cells. Luciferase reporter assay results revealed that miR-455-5p is able to bind with the 3'-untranslated region of Rab31 mRNA to regulate its expression. In summary, the results of the present study suggest that miR-455-5p expression is decreased in ESCC tissues and is miR-455-5p is negatively correlated with lymphatic metastasis and differentiation. As a tumor-suppressor gene, miR-455-5p inhibits the proliferation, migration and invasion of ESCC Eca109 cells by suppressing the expression of Rab31.

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.

miR-516b functions as a tumor suppressor by directly modulating CCNG1 expression in esophageal squamous cell carcinoma

BACKGROUND

miR-516b, as a tumor suppressor in several tumors, its regulatory role in esophageal squamous cell carcinoma (ESCC) hasn't been previously reported.

OBJECTIVE

This study was to investigate the potential role of miR-516b in ESCC.

METHODS

miR-516b expression was measured in ESCC tumor specimens and matched adjacent non-cancerous tissues from 80 ESCC patients. The association between miR-516b and clinicopathological features of these patients was analyzed. The effect of miR-516b was evaluated by cell proliferation, migration, invasion and apoptosis assays in ESCC cell line EC9706 and TE-9. The role of miR-516b in vivo was further studied by constructing ESCC xenograft mice model. The direct target of miR-516b was predicted by public miRNA database and confirmed by luciferase reporter assay. The regulation of miR-516b on the target gene was further confirmed in vitro and in vivo. The expressions of proteins related to cell cycle and apoptosis were analyzed by western blot analysis, and cell migration and invasion were assessed by transwell assays.

RESULTS

miR-516b expression was reduced in ESCC tissues and cells, and correlated with advanced TNM stage, depth of invasion, lymphatic metastasis and poorer overall survival in ESCC patients. miR-516b was upregulated by miR-516b mimics repressing cell proliferation, and inducing G1 cell cycle arrest and apoptosis. miR-516b upregulation also suppressed the growth of ESCC xenograft tumor in nude mice and the invasion of ESCC cells via regulating the epithelial-mesenchymal transition pathway. CCNG1 was identified as a direct downstream target of miR-516b.

CONCLUSION

The results demonstrated miR-516b functions as a tumor suppressor by directly modulating CCNG1 expression in ESCC cells, and may be a novel therapeutic and prognostic biomarker for ESCC.