NRAGE is a potential diagnostic biomarker of hepatocellular carcinoma

NRAGE Confers Radiation Resistance in 2D and 3D Cell Culture and Poor Outcome in Patients With Esophageal Squamous Cell Carcinoma

Objective

The purpose of the study is to explore the mechanism of NRAGE enhancing radioresistance of esophageal squamous cell carcinoma (ESCC) in 2D and 3D levels.

Methods

Stably NRAGE-overexpressed ESCC cells and 3D-printing models for ESCC cells were established. Then, cellular malignancy indexes, such as cell morphology, proliferation, radioresistance, motility, apoptosis, cell cycle, and proteins of the Wnt/β-catenin pathway, were compared between radioresistant and its parental cells in 2D and 3D levels. Additionally, 44 paraffin ESCC specimens with radical radiotherapy were selected to examine NRAGE and β-catenin protein expression and analyze the clinical correlation.

Results

Experiments in 2D culture showed that morphology of the Eca109/NRAGE cells was more irregular, elongated spindle-shaped and disappeared polarity. It obtained faster growth ability, stronger resistance to irradiation, enhanced motility, reduced apoptosis ratio and cell cycle rearrangement. Moreover, Western blot results showed β-catenin, p-Gsk-3β and CyclinD1 expressions were induced, while p-β-catenin and Gsk-3β expressions decreased in Eca109/NRAGE cells. Experiments in the 3D-printing model showed Eca109/NRAGE cell-laden 3D scaffolds had the advantage on growth and spheroiding according to the brightfield observation, scanning electron microscopy and Ki-67 IHC staining, and higher expression at the β-catenin protein. Clinical analysis showed that NRAGE expression was higher in tumor tissues than in control tissues of ESCC patients from the Public DataBase. Compared with radiotherapy effective group, both NRAGE total and nuclear and β-catenin nuclear expressions were significantly upregulated from ESCC specimens in invalid group. Further analysis showed a positive and linear correlation between NRAGE nuclear and β-catenin nuclear expressions. Additionally, results from univariate and multivariate analyses revealed NRAGE nuclear expression could serve as a risk factor for ESCC patients receiving radical radiotherapy.

Conclusion

ESCC cells with NRAGE nuclear accumulation demonstrated greater radioresistance, which may be related to the activation of the Wnt/β-catenin signaling pathway. It indicated that NRAGE nuclear expression was a potential biomarker for monitoring radiotherapeutic response.

Regulatory Mechanism of Neurotrophin Receptor-Interacting Melanoma Antigen Coding Gene Homolog (NRAGE) Gene Methylation on Apoptosis of Breast Cancer Cell Under Tyrosine Kinases/Methyl Ethyl Ketone/Extracellular Regulated Protein Kinases Signaling Pathway

The aim of this study was to discover the influence of Neurotrophin receptor-interacting MAGE homolog (NRAGE) gene methylation on proliferation (Pro) and apoptosis (Apo) of breast cancer cell (BCC), and its influence on TrkA/MEK/ERK signaling. BCC lines MCF-7, MDA-MB-231, and normal mammary gland cell (MGC) MCF-10 were selected. Expression of NRAGE mRNA and methylation level in cells was analyzed via reverse transcription-polymerase chain reaction (RT-PCR) and methylation-specific PCR. Different concentrations (0, 5, 10 mol/L) of DNA methylase inhibitor 5-aza-2′-deoxycytidine (5-Aza-CdR) were adopted to treat the BCC cell line. With dimethyl sulfoxide (DMSO) treatment as control, cell count, 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, flow cytometry, and Western blot were adopted to detect the Pro, Apo, relative expression (REP) of Apo-related proteins Bcl-2, Bax, and target proteins TrkA, MEK, and ERK1/2 after different treatments. The results showed that NRAGE mRNA level in MDA-MB-231 and MCF-7 was notably reduced versus MCF-10 (P < 0.05), and they could express methylated NRAGE specifically. 5-Aza-CdR can increase unmethylated NRAGE’s expression in BCC. Cell Pro level of the 5 and 10 mol/L treatments was greatly inhibited than DMSO and 0 mol/L treatments (P < 0.05). Apo rate and Apo-related proteins Bcl-2 and Bax increased obviously (P < 0.05). In addition, the phosphorylation levels of TrkA in the 5 and 10 mol/L treatments were considerably reduced (P < 0.05), while that in MEK and ERK1/2 was remarkably increased (P < 0.05). In short, NRAGE methylation can inhibit BCC’s Pro and regulate BCC’s Pro and Apo through TrkA/MEK/ERK signaling.

Bioinformatics analysis of molecular genetic targets and key pathways for hepatocellular carcinoma

Background

Hepatocellular carcinoma (HCC) is the second leading cause of death among cancers worldwide. In this study, we aimed to identify the molecular target genes and detect the key mechanisms of HCC. Three gene expression profiles (GSE84006, GSE14323, GSE14811) and two miRNA expression profiles (GSE40744, GSE36915) were analyzed to determine the molecular target genes, microRNAs (miRNAs) and the potential molecular mechanisms in HCC.

Methods

All profiles were extracted from the Gene Expression Omnibus database. The identification of the differentially expressed genes (DEGs) was analyzed by the GEO2R method. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway and gene ontology (GO) enrichment analysis performed database for Integrated Discovery, Visualization and Annotation. The miRNA-gene network and protein–protein interaction (PPI) network were correlated by the Cytoscape software. The key target genes were identified by the CytoHubba plugin, Molecular Complex Detection (MCODE) plugin and miRNA-gene network. The identified hub genes were testified for survival curve using the Kaplan–Meier plotter database.

Results

Expression profiles had 592 overlapped DEGs. The majority of the DEGs were enriched in membrane-bounded organelles and intracellular membrane-bounded organelles. These DEGs were significantly enriched in metabolic, protein processing in the endoplasmic reticulum and thyroid cancer pathways. PPI network analysis showed these genes were mostly involved in the pathogenic Escherichia coli infection and the regulation of actin cytoskeleton pathways. Combining these results, we identified 10 key genes involving in the progression of HCC. Finally, PLK1, PRCC, PRPF4 and PSMA7 exhibited higher expression levels in HCC patients with poor prognosis than those for lower expression via Kaplan–Meier plotter database.

Conclusion

PLK1, PRCC, PRPF4 and PSMA7 could be potential biomarkers or therapeutic targets for HCC. Meanwhile, the metabolic pathway, protein processing in the endoplasmic reticulum and the thyroid cancer pathway may play vital roles in the progression of HCC.