MicroRNA-374b inhibits the tumor growth and promotes apoptosis in non-small cell lung cancer tissue through the p38/ERK signaling pathway by targeting JAM-2

Impact of the Junction Adhesion Molecule-A on Asthma

PURPOSE

Junctional adhesion molecule (JAM)-A is an immunoglobulin-like molecule that colocalizes with tight junctions (TJs) in the endothelium and epithelium. It is also found in blood leukocytes and platelets. The biological significance of JAM-A in asthma, as well as its clinical potential as a therapeutic target, are not well understood. The aim of this study was to elucidate the role of JAM-A in a mouse model of asthma, and to determine blood levels of JAM-A in asthmatic patients.

MATERIALS AND METHODS

Mice sensitized and challenged with ovalbumin (OVA) or saline were used to investigate the role of JAM-A in the pathogenesis of bronchial asthma. In addition, JAM-A levels were measured in the plasma of asthmatic patients and healthy controls. The relationships between JAM-A and clinical variables in patients with asthma were also examined.

RESULTS

Plasma JAM-A levels were higher in asthma patients (n=19) than in healthy controls (n=12). In asthma patients, the JAM-A levels correlated with forced expiratory volume in 1 second (FEV₁%), FEV₁/forced vital capacity (FVC), and the blood lymphocyte proportion. JAM-A, phospho-JNK, and phospho-ERK protein expressions in lung tissue were significantly higher in OVA/OVA mice than in control mice. In human bronchial epithelial cells treated with house dust mite extracts for 4 h, 8 h, and 24 h, the JAM-A, phospho-JNK, and phospho-ERK expressions were increased, as shown by Western blotting, while the transepithelial electrical resistance was reduced.

CONCLUSION

These results suggest that JAM-A is involved in the pathogenesis of asthma, and may be a marker for asthma.

CRISPR-Cas9-mediated gene therapy in lung cancer

As the largest cause of cancer-related deaths worldwide, pulmonary cancer is the most common form of the disease. Several genetic, epigenetic, and environmental factors come into play during the multi-step mechanism of tumorigenesis. The heterogeneity that makes discovering successful therapeutics for pulmonary cancer problematic is significantly influenced by the epigenetic landscape, including DNA methylation, chromatin architecture, histone modifications, and noncoding RNA control. Clinical activity of epigenetic-targeted medicines has been reported in hematological tumors, and these compounds may also have therapeutic effects in solid tumors. Over the course of the past few years, some researchers have successfully modified the expression of genes in cells using the clustered regularly interspaced short palindromic repeats (CRISPR)-Cas (CRISPR-associated proteins) technique. The utilization of this technology allows for the induction of site-specific mutagenesis, epigenetic alterations, and the regulation of gene expression. This study will present an overview of the primary epigenetic alterations seen in pulmonary cancer, as well as a summary of therapeutic implications for targeting epigenetics in the management of pulmonary cancer, with a particular emphasis on the technique known as CRISPR/Cas9.

MicroRNA-139 Facilitates Non-Small Cell Lung Cancer Progression via Modulating the Epidermal Growth Factor Receptor (EGFR)/Mitogen-Activated Protein Kinase (MEK)/Extracellular Signal-Regulated Kinase (ERK) Signaling Pathway

We aimed to elucidate the role of miR-139 in the progression of non-small cell lung cancer (NSCLC) and its underlying mechanisms. Tumor tissues and paracancerous tissues were collected to obtain NSCLC cells and normal pulmonary epithelial cells, respectively. The expression of miR-139 in tissues and cells were determined via real-time quantitative PCR. The NSCLC cells were transfected with miR-139 inhibitor, siRNA-NC, miR-139 mimics, or vectors, respectively, followed by expression measurement of miR-139 via PCR. Colony formation and CCK-8 assays were employed to assess the cellular proliferation, along with transwell experiment for investigating the tendency of cancer cells in invasion and metastasis. The expression levels of proteins were semi-quantified via Western Blot analysis, including proteins involved in the epidermal growth factor receptor (EGFR)/mitogen-activated protein kinase (MEK)/extracellular signal-regulated kinase (ERK) pathway and those related to epithelial-mesenchymal transition (EMT). For rescue experiments, an EGFR agonist was applied to transfect cells, followed by the detection of potentials of cancer cells in proliferation and invasion along with the expression determination of the proteins involved. Eventually, mouse xenograft models were established using cells transfected with miR-139 inhibitor or siRNA-NC, respectively, of which the tumor development was monitored and the expression of EGFR in the tumor tissues of the mouse xenograft models was detected via immunohistochemical staining. A significant increase of miR-139 was detected in NSCLC tissues, of which the elevation was related to the tumor size, malignancy, and poor prognosis. Compared with cells in the control group, miR-139 inhibition enhanced the proliferation of NSCLC cells both in vivo and in vitro, which was accompanied by the suppressed expression of proteins related to the EMT process, along with the enhanced potentials cell invasion and migration. Additionally, miR-139 modulated EGFR expression and activated its signal transduction in EGFR/MEK/ERK pathway to exert its carcinogenic function. MiRNA-139 may facilitate NSCLC progression via modulating the EGFR/MEK/ERK signal-transduction pathway.

Development and validation of a nomogram with an epigenetic signature for predicting survival in patients with lung adenocarcinoma

Epigenetic factors play crucial roles in carcinogenesis by modifying chromatin architecture. Here, we established an epigenetic biosignature-based model for examining survival in patients with lung adenocarcinoma (LUAD). We retrieved gene-expression profiles and clinical data from The Cancer Genome Atlas and Gene Expression Omnibus and clustered the data into training (n = 490) and Validation (n = 226) datasets, respectively. To establish an epigenetic model, we identified prognostic epigenetic regulation-related genes by LASSO and Cox regression analyses, and established a novel 11-gene signature, including EPC1, GADD45A, HCFC2, RCOR1, SMARCAL1, TLE2, TRIM28, and ZNF516, for predicting LUAD overall survival (OS). The biosignature performed optimally in both the training and validation sets according to receiver operating characteristic and calibration plots. Moreover, the biosignature classified patients into high- and low-risk clusters with distinct survival times, with Cox regression analysis revealing the biosignature as an independent LUAD prognostic index. Furthermore, the generated nomogram integrating the prognostic gene biosignature and clinical indices predicted LUAD OS with high efficiency and outperformed tumor-node-metastasis staging in LUAD survival prediction. These results demonstrated the efficacy of the epigenetic signature prognostic nomogram for reliably predicting LUAD OS and its potential application for informing clinical decision making and individualized treatment.

Relationship between apical junction proteins, gene expression and cancer

The apical junctional complex (AJC) is a cell-cell adhesion system present at the upper portion of the lateral membrane of epithelial cells integrated by the tight junction (TJ) and the adherens junction (AJ). This complex is crucial to initiate and stabilize cell-cell adhesion, to regulate the paracellular transit of ions and molecules and to maintain cell polarity. Moreover, we now consider the AJC as a hub of signal transduction that regulates cell-cell adhesion, gene transcription and cell proliferation and differentiation. The molecular components of the AJC are multiple and diverse and depending on the cellular context some of the proteins in this complex act as tumor suppressors or as promoters of cell transformation, migration and metastasis outgrowth. Here, we describe these new roles played by TJ and AJ proteins and their potential use in cancer diagnostics and as targets for therapeutic intervention.

Current Landscape of Epigenetics in Lung Cancer: Focus on the Mechanism and Application

Lung cancer is the leading cause of cancer-related mortality worldwide. Tumorigenesis involves a multistep process resulting from the interactions of genetic, epigenetic, and environmental factors. Genome-wide association studies and sequencing studies have identified many epigenetic alterations associated with the development of lung cancer. Epigenetic mechanisms, mainly including DNA methylation, histone modification, and noncoding RNAs (ncRNAs), are heritable and reversible modifications that are involved in some important biological processes and affect cancer hallmarks. We summarize the major epigenetic modifications in lung cancer, focusing on DNA methylation and ncRNAs, their roles in tumorigenesis, and their effects on key signaling pathways. In addition, we describe the clinical application of epigenetic biomarkers in the early diagnosis, prognosis prediction, and oncotherapy of lung cancer. Understanding the epigenetic regulation mechanism of lung cancer can provide a new explanation for tumorigenesis and a new target for the precise treatment of lung cancer.

Tumor promoting effects of glucagon receptor: a promising biomarker of papillary thyroid carcinoma via regulating EMT and P38/ERK pathways

Glucagon is a crucial hormone involved in the maintenance of glucose homeostasis. Large efforts to define the role of glucagon receptor (GCGR) have been continuously made in recent years, but it is still incomplete about its function and mechanism. We performed this study to verify its potential impacts on papillary thyroid carcinoma (PTC) progression. Correlation between GCGR expression and PTC was elaborated using The Cancer Genome Atlas (TCGA) database. The Kaplan-Meier method was used to analyze the connection between GCGR expression and prognosis of PTC patients. GCGR expression was measured by quantitative real-time polymerase chain reaction (qRT-PCR) and western blot analysis; simultaneously, cell viability was elucidated using cell proliferation and colony formation assays following siRNAs strategy. Transwell analyses were conducted to measure the invasion and migration of PTC cells. Flow cytometry analysis was conducted to examine apoptotic ability. The cAMP ELISA kit was employed to measure the cAMP level in PTC cells. Our data determined that the expression level of GCGR was increased in PTC tissues and cells in contrast to normal tissues and Nthy-ori 3-1, respectively. Up-regulated GCGR expression was linked with the lower survival rate in patients with PTC. Functional analysis in vitro suggested that GCGR knockdown attenuated PTC cell proliferation, colony formation, invasion, and migration whilst intensified apoptosis. Down-regulated GCGR was able to increase cAMP level. Furthermore, reduction of GCGR could result in the inactivation of epithelial-mesenchymal transition (EMT) and P38/ERK pathways. In conclusion, the findings of this study disclosed that GCGR promoted PTC cell behaviors by mediating the EMT and P38/ERK pathways, serving as a potential diagnostic and prognostic biomarker as well as therapeutic target for PTC.

Survival-based bioinformatics analysis to identify hub genes and key pathways in non-small cell lung cancer

BACKGROUND

Lung cancer is one of the leading causes of cancer mortality worldwide. Here, we performed an integrative bioinformatics analysis to screen hub genes and critical pathways in non-small cell lung cancer (NSCLC) based on the overall survival rate of differentially expressed genes (DEGs).

METHODS

Four datasets from the gene expression omnibus (GEO) were used to identify the DEGs. To obtain robust DEGs in NSCLC, only the DEGs that co-existed in the four datasets were selected for subsequent analysis. To identify the genes correlated with overall survival, the overall survival of these genes was then analyzed using the Kaplan-Meier plotter database. The genes significantly correlated with survival were used to perform gene ontology (GO) and Kyoto encyclopedia of genes and genomes (KEGG) analysis; next, these genes were used to construct a protein-protein interaction network. MCODE and CytoHubba were used to identify the clusters and hub genes. Finally, the hub genes were validated in the Cancer Genome Atlas (TCGA) and the Human Protein Atlas (HPA).

RESULTS

We found 522 up-regulated DEGs, and 989 down-regulated DEGs between the NSCLC and normal lung tissue, and 895 of them were correlated with a higher overall survival. GO analysis showed that the DEGs that were associated with a higher overall survival were enriched in cell division, cell cycle, DNA replication, angiogenesis, and cell migration. KEGG analysis was consistent with GO analysis and showed that p53 signaling pathway, pyrimidine metabolism, cGMP-PKG signaling pathway and renin secretion pathway were associated with overall survival in NSCLC. In the protein-protein analysis, we identified seven clusters and six hub genes which were BUB1B, CCNB1, CENPE, KIF18A, NDC10, and MAD2L1. Of these genes, CENPE and KIF18A had not been reported until now. Finally, the dysregulated expression of the six hub genes was validated by the data from the TCGA and HPA.

CONCLUSIONS

We identified the hub genes and potential mechanisms of NSCLC based on multiple-microarray analysis and overall survival; then, validated the hub genes in the TCGA and HPA database. These hub genes may serve as potential therapeutic targets.

Key modules and hub genes identified by coexpression network analysis for revealing novel biomarkers for larynx squamous cell carcinoma

Larynx squamous cell carcinoma (LSCC) is the second most aggressive head and neck squamous cell carcinoma. Numerous genes have been identified to be aberrantly expressed during the development of LSCC. However, currently, researchers focus more on the individual molecule and downstream genes, leaving the coexpression among genes and key upstream disease driver genes unexploited. In this study, we applied weighted gene coexpression analysis (WGCNA) to decipher potential hub genes driving the development of LSCC. After downloading of LSCC microarray profile from gene expression omnibus, different expression analysis was performed, which was used to conduct functional enrichment analysis. Then, we applied WGCNA to highlight the hub genes which were relevant to the carcinogenesis and progression. A total of 2858 differentially expressed genes were identified in LSCC samples compared with adjacent non-neoplastic tissues. WGCNA revealed three LSCC set-specific modules having significant Kyoto Encyclopedia of Genes and Genomes enrichment effect, including pink, cyan, and black module. Nine hub genes were identified to be crucial in LSCC onset and progression, which may assist clinical decisions and serve as potential targets for LSCC treatment.

microRNA-612 suppresses the malignant development of non-small-cell lung cancer by directly targeting bromodomain-containing protein 4

Background: Aberrant expression of microRNAs (miRNAs) in non-small-cell lung cancer (NSCLC) has been reported. Dysregulation of miRNAs exerts tumor-suppressing or tumor-promoting actions on the pathology and biological behaviors of NSCLC. miR-612 is associated with many types of human cancer; however, the expression, potential roles, and regulatory mechanisms of miR-612 in NSCLC remain unclear.

Material and methods: Here, the expression level of miR-612 in NSCLC tissue specimens and a panel of cell lines were evaluated by RT-qPCR. Cell-Counting Kit 8, flow cytometry, Transwell migration and invasion, and in vivo tumor growth assays were performed to determine the functional role of miR-612 in malignant phenotypes of NSCLC cells. The molecular mechanism underlying the tumor-suppressive roles of miR-612 in NSCLC was investigated.

Results: miR-612 was expressed at low levels in NSCLC, and low miR-612 expression was significantly correlated with TNM stage and lymph node metastasis. NSCLC patients with low miR-612 expression had shorter overall survival rate than those with high levels. Exogenous miR-612 expression decreased proliferation, migration, and invasion, and promoted apoptosis of NSCLC cells in vitro. miR-612 upregulation hindered NSCLC tumor growth in vivo. Bromodomain-containing protein 4 (BRD4) was confirmed as a direct target gene of miR-612 in NSCLC cells. BRD4 was obviously overexpressed in human NSCLC tissues and inverse correlated with miR-612 expression. Inhibition of BRD4 expression simulated the tumor-suppressive functions of miR-612 overexpression in NSCLC cells. Reintroduction of miR-612 expression abrogated the miR-612-mediated suppressive effects on NSCLC cells. BRD4 upregulation inhibited activation of the PI3K/Akt pathway in NSCLC cells in vitro and in vivo.

Conclusion: This study supports the first evidence that miR-612 exerts tumor-suppressive roles in the aggressive behaviors of NSCLC cells in vitro and in vivo through direct targeting BRD4 and deactivating the PI3K/Akt pathway. Thus, miR-612 might be a promising target for anticancer therapies in patients with NSCLC.

MicroRNA-625 inhibits the progression of non‑small cell lung cancer by directly targeting HOXB5 and deactivating the Wnt/β-catenin pathway

Numerous microRNAs (miRs) are dysregulated in non‑small cell lung cancer (NSCLC), serving pivotal roles in its formation and progression. miR‑625 is dysregulated in several types of human cancer, but its involvement in the formation and development of NSCLC remains poorly understood. In the present study, we aimed to investigate miR‑625 expression in NSCLC and its role in regulating NSCLC cell behavior. miR‑625 expression in NSCLC tissues and cell lines was detected using reverse transcription‑quantitative polymerase chain reaction. The effects of miR‑625 overexpression on NSCLC cell proliferation, apoptosis, migration and invasion in vitro were assessed using an MTT assay, flow cytometry, and cell migration and invasion assays, respectively. The effects of miR‑625 upregulation on NSCLC growth were evaluated in an in vivo xenograft model. The molecular mechanisms underlying the tumor‑suppressing roles of miR‑625 in NSCLC were explored in detail. miR‑625 expression was determined to be downregulated in NSCLC tissues and cell lines. This decreased expression was associated with advanced clinical features and poor overall survival of patients with NSCLC. Exogenous miR‑625 expression suppressed NSCLC cell proliferation, migration and invasion, and induced apoptosis in vitro. miR‑625 upregulation hindered NSCLC tumor growth in vivo. Homeobox B5 (HOXB5) was proposed to be the direct target gene of miR‑625 in NSCLC cells. The tumor‑suppressing effects of HOXB5 silencing were similar to those of miR‑625 overexpression in NSCLC cells. In rescue experiments, HOXB5 overexpression partially reversed the inhibitory effects of miR‑625 in NSCLC cells. miR‑625 upregulation directly targeted HOXB5 to deactivate the Wnt/β‑catenin signaling pathway in NSCLC cells in vitro and in vivo. miR‑625 was determined to be associated with HOXB5 suppression and Wnt/β‑catenin pathway deactivation, which in turn inhibited the aggressive behavior of NSCLC cells in vitro and in vivo.