LncRNA-ECM is overexpressed in esophageal squamous cell carcinoma and promotes tumor metastasis

Upregulated miR‑378a‑3p expression suppresses energy metabolism and promotes apoptosis by targeting a GLUT‑1/ALDOA/PKM2 axis in esophageal carcinoma

Esophageal squamous cell carcinoma (ESCC) is an aggressive malignancy of the digestive system with increasing incidence and mortality rates. The biological roles of microRNA (miR)-378a-3p in tumor cells remain contested, and the mechanisms underlying the functions, energy metabolism, and cell survival mechanisms in ESCC cells are yet to be fully elucidated. In the present study, miR-378a-3p overexpression and negative control plasmids were transfected into ECA-109 cells using electroporation. Western blotting was used to detect the relative expression of proteins, and flow cytometry was used to detect cell apoptosis. Subsequently, ELISA assays were performed to determine enzyme activity, and an ATP detection kit was used to measure ATP content. Dual-luciferase reporter assays were performed to identify the target genes of miR-378a-3p. The results of the present study demonstrated that miR-378a-3p inhibited the gene expression and enzyme activities of glucose transporter protein 1 (GLUT-1), Aldolase A (ALDOA), and pyruvate kinase M2 (PKM2), all of which are involved in the glycolytic pathway of cells. Energy metabolism was suppressed by miR-378a-3p by reducing ATP content, and this downregulated the expression of Bcl-2 and Survivin. Moreover, increased miR-378a-3p expression promoted cell apoptosis in the early stages by increasing the expression levels and the activity of Bad and Caspase-3, while inhibiting the expression levels of Bcl-2 and Survivin. The results of the present study also demonstrated that GLUT-1/ALDOA/PKM2 were target genes of miR-378a-3p. Notably, miR-378a-3p blocked energy production and promoted the apoptosis of tumor cells via the downregulation of glycolytic enzyme expression and by reducing the mitochondrial membrane potential in ESCC. Bad, Caspase-3, Survivin, and Bcl-2 may be associated with blocking energy production and promoting apoptosis via miR-378a-3p in ESCC cells.

A Pleiotropic Role of Long Non-Coding RNAs in the Modulation of Wnt/β-Catenin and PI3K/Akt/mTOR Signaling Pathways in Esophageal Squamous Cell Carcinoma: Implication in Chemotherapeutic Drug Response

Despite the availability of modern techniques for the treatment of esophageal squamous cell carcinoma (ESCC), tumor recurrence and metastasis are significant challenges in clinical management. Thus, ESCC possesses a poor prognosis and low five-year overall survival rate. Notably, the origin and recurrence of the cancer phenotype are under the control of complex cancer-related signaling pathways. In this review, we provide comprehensive knowledge about long non-coding RNAs (lncRNAs) related to Wnt/β-catenin and phosphatidylinositol-3-kinase (PI3K)/protein kinase B (Akt)/mammalian target of rapamycin (mTOR) signaling pathway in ESCC and its implications in hindering the efficacy of chemotherapeutic drugs. We observed that a pool of lncRNAs, such as HERES, TUG1, and UCA1, associated with ESCC, directly or indirectly targets various molecules of the Wnt/β-catenin pathway and facilitates the manifestation of multiple cancer phenotypes, including proliferation, metastasis, relapse, and resistance to anticancer treatment. Additionally, several lncRNAs, such as HCP5 and PTCSC1, modulate PI3K/Akt/mTOR pathways during the ESCC pathogenesis. Furthermore, a few lncRNAs, such as AFAP1-AS1 and LINC01014, block the efficiency of chemotherapeutic drugs, including cisplatin, 5-fluorouracil, paclitaxel, and gefitinib, used for ESCC treatment. Therefore, this review may help in designing a better therapeutic strategy for ESCC patients.

Transcriptomic and microRNA Expression Profiles Identify Biomarkers for Predicting Neo-Chemoradiotherapy Response in Esophageal Squamous Cell Carcinomas (ESCC)

Neo-chemoradiotherapy (nCRT) before surgery is a standard treatment for locally advanced esophageal cancers. However, the treatment outcome of nCRT varied with different patients. This study aimed to identify potential biomarkers for prediction of nCRT-response in patients with esophageal squamous cell carcinoma (ESCC). Microarray datasets of nCRT responder and non-responder samples (access number GSE45670 and GSE59974) of patients with ESCC were downloaded from Gene Expression Omnibus (GEO) database. The mRNA expression profiles of cancer biopsies from four ESCC patients were analyzed before and after nCRT. Differentially expressed genes (DEGs) and miRNAs were screened between nCRT responder and non-responder ESCC samples. Functional enrichment analysis was conducted for these DEGs followed by construction of protein-protein interaction (PPI) network and miRNA-mRNA regulatory network. Finally, univariate survival analysis was performed to identify candidate biomarkers with prognostic values in ESCC. We identified numerous DEGs and differentially expressed miRNAs from nCRT responder group. GO and KEGG analysis showed that the dysregulated genes were mainly involved in biological processes and pathways, including "response to stimulus", "cellular response to organic substance", "regulation of signal transduction", "AGE-RAGE signaling pathway in diabetic complications", and "steroid hormone biosynthesis". After integration of PPI network and miRNA-mRNA network analysis, we found eight genes, TNF, AKR1C1, AKR1C2, ICAM1, GPR68, GNB4, SERPINE1 and MMP12, could be candidate genes associated with disease progression. Univariate cox regression analysis showed that there was no significant correlation between dysregulated miRNAs (such as hsa-miR-34b-3p, hsa-miR-127-5p, hsa-miR-144-3p, and hsa-miR-486-5p, et al.) and overall survival of ESCC patients. Moreover, abnormal expression of MMP12 was significantly correlated with pathological degree, TNM stage, lymph nodes metastasis, and overall survival of ESCC patients (p < 0.05). Taken together, our study identified that MMP12 might be a useful tumor biomarker and therapeutic target for ESCC.

Bioinformatics-based analysis of the lncRNA-miRNA-mRNA and TF regulatory networks reveals functional genes in esophageal squamous cell carcinoma

Esophageal squamous cell carcinoma (ESCC) is a 5-year survival rate unsatisfied malignancies. The study aimed to identify the novel diagnostic and prognostic targets for ESCC. Expression profiling (GSE89102, GSE97051, and GSE59973) data were downloaded from the GEO database. Then, differentially expressed (DE) lncRNAs, DEmiRNAs, and genes (DEGs) with P-values < 0.05, and |log₂FC| ≥ 2, were identified using GEO2R. Functional enrichment analysis of miRNA-related mRNAs and lncRNA co-expressed mRNA was performed. LncRNA–miRNA–mRNA, protein–protein interaction of miRNA-related mRNAs and DEGs, co-expression, and transcription factors-hub genes network were constructed. The transcriptional data, the diagnostic and prognostic value of hub genes were estimated with ONCOMINE, receiver operating characteristic (ROC) analyses, and Kaplan–Meier plotter, respectively. Also, the expressions of hub genes were assessed through qPCR and Western blot assays. The CDK1, VEGFA, PRDM10, RUNX1, CDK6, HSP90AA1, MYC, EGR1, and SOX2 used as hub genes. And among them, PRDM10, RUNX1, and CDK6 predicted worse overall survival (OS) in ESCC patients. Our results showed that the hub genes were significantly up-regulated in ESCA primary tumor tissues and cell lines, and exhibited excellent diagnostic efficiency. These results suggest that the hub genes may server as potential targets for the diagnosis and treatment of ESCC.

Involvement of long non-coding RNAs in the progression of esophageal cancer

Esophageal cancer (EC) is one of the most common malignant tumors of the digestive system with high incidence and mortality rate worldwide. Therefore, exploring the pathogenesis of EC and searching for new targeted therapies are the current research hotspot for EC treatment. Long non‐coding RNAs (lncRNAs) are endogenous RNAs with more than 200 nucleotides, but without protein‐coding function. In recent years, lncRNAs have gradually become the focuses in the field of non‐coding RNA. Some lncRNAs have been proved to be closely related to the pathogenesis of EC. Many lncRNAs are abnormally expressed in EC and participate in many biological processes including cell proliferation, apoptosis, and metastasis by inhibiting or promoting target gene expression. LncRNAs can also regulate the progression of EC through epithelial‐mesenchymal transformation (EMT), which is closely related to the occurrence, development, and prognosis of EC. In this article, we review and discuss the involvement of lncRNAs in the progression of EC.

LOC441178 Overexpression Inhibits the Proliferation and Migration of Esophageal Carcinoma Cells via Methylation of miR-182

Background

Long noncoding RNAs (lncRNAs) have been shown to play an important role in the development and progression of esophageal carcinoma (EC). Recently, lncRNA LOC441178 was shown to be dysregulated in many cancer types; however, the role of LOC441178 in EC remains unclear.

Materials and Methods

Flow cytometry, transwell and wound healing assays were used to measure the apoptosis and migration in esophageal squamous cell carcinoma (ESCC) cells. RT-qPCR was used to detect the level of miR-182 in LOC441178-overexpressed EC cells. In addition, DNA methylation status of miR-182 promoter in LOC441178-overexpressed ESCC cells was detected by methylation-specific PCR (MSP) and bisulfite sequencing PCR.

Results

In this study, we found that LOC441178 negatively regulated miR-182 expression in ESCC cells. In addition, overexpression of LOC441178 inhibited the proliferation and migration and induced apoptosis in ESCC cells via downregulation of miR-182. Moreover, overexpression of LOC441178 markedly inhibited the phosphorylation of Akt and phosphorylation FOXO3a and increased the expression of FOXO3a in ESCC cells via downregulation of miR-182. Mechanistically, LOC441178 overexpression epigenetically suppressed miR-182 expression via DNA methylation. In vivo experiments revealed that overexpression of LOC441178 inhibited ESCC tumor growth in mouse xenograft model.

Conclusion

Collectively, our data suggested that LOC441178 overexpression epigenetically inhibited tumorigenesis of ESCC via DNA methylation of miR-182. These data indicated that the LOC441178/miR-182 axis might represent a novel therapeutic option for the treatment of ESCC.

Downregulation of lncRNA-HEIH curbs esophageal squamous cell carcinoma progression by modulating miR-4458/PBX3

Background

Long non‐coding RNAs (lncRNAs) have been found to play a specific part in the development of esophageal squamous cell carcinoma (ESCC), except for lncRNA HEIH. Here, we aimed to discover the molecular mechanisms of HEIH in ESCC.

Methods

We detected the expression level of HEIH and miR‐4458 in ESCC tissues and cells using qRT‐PCR assay. A dual luciferase reporter assay was used to check the relationship between HEIH, miR‐4458 or PBX3. Counting Clock Kit‐8 (CCK‐8) assay and transwell assay were used to detect ESCC cell proliferation and invasion capability. Western blot analysis was used to measure the protein expression level of PBX3.

Results

HEIH was confirmed to be upregulated in both ESCC tissues and cell lines. Inversely, there was a downregulation of miR‐4458 in ESCC tissues and cell lines. Functionally, we noticed that depletion of HEIH restrained ESCC cell viability, and invasion capability. Moreover, PBX silencing was found to restrain ESCC cell progression, while miR‐4458 or HEIH vector both could alleviate its suppressive effect.

Conclusions

The present study clarified that HEIH regulated ESCC progression by suppressing miR‐4458 and upregulating PBX3. Our findings suggested that HEIH could be a possible therapeutic target for ESCC treatment.

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.

Co-expression analysis and ceRNA network reveal eight novel potential lncRNA biomarkers in hepatocellular carcinoma

BACKGROUND

Hepatocellular carcinoma (HCC) is the most common primary liver cancer in the world, with a high degree of malignancy and recurrence. The influence of the ceRNA network in tumor on the biological function of liver cancer is very important, It has been reported that many lncRNA play a key role in liver cancer development. In our study, integrated data analysis revealed potential eight novel lncRNA biomarkers in hepatocellular carcinoma.

METHODS

Transcriptome data and clinical data were downloaded from the The Cancer Genome Atlas (TCGA) data portal. Weighted gene co-expression network analysis was performed to identify the expression pattern of genes in liver cancer. Then, the ceRNA network was constructed using transcriptome data.

RESULTS

The integrated analysis of miRNA and RNAseq in the database show eight novel lncRNAs that may be involved in important biological pathways, including TNM and disease development in liver cancer. We performed function enrichment analysis of mRNAs affected by these lncRNAs.

CONCLUSIONS

By identifying the ceRNA network and the lncRNAs that affect liver cancer, we showed that eight novel lncRNAs play an important role in the development and progress of liver cancer.

Knockdown of lncRNAXLOC_001659 inhibits proliferation and invasion of esophageal squamous cell carcinoma cells

BACKGROUND

Studies have shown that long non-coding RNAs (lncRNAs) play a key role in almost all key physiological and pathological processes, including different types of malignant tumors. Our previous lncRNA microarray results have shown that lncRNA XLOC_001659 is upregulated in esophageal cancer (EC) tissues, with a fold change of 20.9 relative to normal esophageal tissues. But its effect and the molecular biological mechanisms on proliferation and invasion of EC cells remain unclear.

AIM

To investigate the effect of lncRNA XLOC_001659 on esophageal squamous cell carcinoma (ESCC) cells and explore the molecular biological mechanisms involved.

METHODS

RT-qPCR assay was used to quantify the expression levels of lncRNAXLOC-001659 and miR-490-5p. The proliferative capacity of the cells was determined using CCK8 and colony formation assays, and the effect of lncRNAXLOC-001659 on the invasion of ESCC cells was determined by Transwell assay. Dual-luciferase reporter assay was used to detect the target genes of lncRNAXLOC-001659 and miR-490-5p.

RESULTS

The results of RT-qPCR showed that the expression of lncRNAXLOC_001659 was upregulated in ESCC cells. CCK-8 assay showed that knockdown of lncRNAXLOC_001659 significantly inhibited ESCC cell proliferation. Colony formation and Transwell invasion assays showed that knockdown of lncRNAXLOC_001659 or overexpression of miR-490-5p significantly inhibited ESCC cell growth and invasion. Furthermore, lncRNAXLOC_001659 acts as an endogenous sponge by competitively binding to miR-490-5p to downregulate miR-490-5p. Further results confirmed that miR-490-5p targeted PIK3CA, and the recovery of PIK3CA rescued lncRNAXLOC_001659 knockdown or miR-490-5p overexpression-mediated inhibition of cell proliferation and invasion, which suggested the presence of an lncRNAXLOC_001659/miR-490-5p/PIK3CA regulatory axis.

CONCLUSION

Knockdown of lncRNA XLOC_001659 inhibits proliferation and invasion of ESCC cells via regulation of miR-490-5p/PIK3CA, suggesting that it may play a role in ESCC tumorigenesis and progression.

Gross tumor volume is an independent prognostic factor in patients with postoperative locoregional recurrence of esophageal squamous cell carcinoma

Many cases of esophageal squamous cell carcinoma (ESCC) involve lymph node and distant metastases after esophagectomy, and most patients relapse within 2 years. Intensity-modulated radiotherapy (IMRT) is an important treatment for these cases of recurrence in ESCC and is widely used in clinical practice. A retrospective study of 137 postoperative patients with locoregional recurrences of ESCC who received IMRT was carried out. Kaplan-Meier survival curves and log-rank tests of univariate analysis was performed to assess whether there was a significant association between demographic and clinical features and death after recurrence. For multivariate analysis, the statistically significant results from the Kaplan-Meier method were subjected to Cox regression analysis. A total of 109 male and 28 female patients were included. There were 21 (15.3%), 58 (42.3%), 36 (26.3%), 3 (2.2%), 17 (12.4%), and 2 (1.5%) recurrences in the anastomotic, supraclavicular, mediastinal, tumor bed, polyregional, and abdominal regions, respectively. Univariate analysis showed that the gross tumor volume (GTV) of radiation (<27 vs. ≥27 cm³) and the number of lymph nodes were significantly associated with survival. The survival rates of patients at 1, 2, 3 and 5 years with GTV<27 cm³ were 72.7, 51.5, 37.1 and 25.9%, respectively, and with GTV≥27 cm³ were 63.7, 26.9, 17.9 and 0%, respectively. The significant independent prognostic factor was GTV [<27 vs. ≥27 cm³; hazard ratio (HR), 1.746; 95% confidence interval (CI), 1.112–2.741]. In conclusion, GTV of radiation (<27 vs. ≥27 cm³) is an independent factor in predicting locoregional recurrence after ESCC. Patients with GTV<27 cm³ are likely to have a better prognosis.