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Purpose: This study aimed to investigate the expression and function of interferon regulatory factor-1 (IRF-1) in non-small cell lung cancer (NSCLC). Methods: IRF-1 expression and its prognostic value were investigated through bioinformatic analysis. The protein expression levels of IRF-1, cleaved caspase-3, and LC3-I/II were analyzed by western blotting. A lentiviral vector was used to overexpress or knockdown IRF-1 in vitro. Mitochondrial membrane potential (MMP) and reactive oxygen species (ROS) were analyzed by JC-1 and DCFH-DA staining, respectively. ATP, SOD, MDA, cell viability, LDH release, and caspase-3 activity were evaluated using commercial kits. Results: Compared to the levels in normal tissues, IRF-1 expression was significantly lower in lung cancer tissues and was a prognostic factor for NSCLC. Cisplatin treatment induced IRF-1 activation, ROS production, ATP depletion, SOD consumption, and MDA accumulation in A549 lung cancer cells. IRF-1 overexpression promoted mitochondrial depolarization, oxidative stress, and apoptotic cell death and inhibited autophagy in A549 cells, and these effects could be reversed by IRF-1 knockdown. Conclusion: These data suggest that IRF-1 regulates apoptosis, autophagy and oxidative stress, which might be served as a potential target for increasing chemotherapy sensitivity of lung cancer.

Introduction: Chronic obstructive pulmonary disease (COPD) is an independent risk factor of non-small cell lung cancer (NSCLC). This study aimed to analyze the key genes and potential molecular mechanisms that are involved in the development from COPD to NSCLC. Methods: Expression profiles of COPD and NSCLC in GSE106899, GSE12472, and GSE12428 were downloaded from the Gene Expression Omnibus (GEO) database, followed by identification of the differentially expressed genes (DEGs) between COPD and NSCLC. Based on the identified DEGs, functional pathway enrichment and lung carcinogenesis-related networks analyses were performed and further visualized with Cytoscape software. Then, principal component analysis (PCA), cluster analysis, and support vector machines (SVM) verified the ability of the top modular genes to distinguish COPD from NSCLC. Additionally, the corrections between these key genes and clinical staging of NSCLC were studied using the UALCAN and HPA websites. Finally, a prognostic risk model was constructed based on multivariate Cox regression analysis. Kaplan-Meier survival curves of the top modular genes on the training and verification sets were generated. Results: A total of 2350, 1914, and 1850 DEGs were obtained from GSE106899, GSE12472, and GSE12428 datasets, respectively. Following analysis of protein-protein interaction networks, the identified modular gene signatures containing H2AFX, MCM2, MCM3, MCM7, POLD1, and RPA1 were identified as markers for discrimination between COPD and NSCLC. The modular gene signatures were mainly enriched in the processes of DNA replication, cell cycle, mismatch repair, and others. Besides, the expression levels of these genes were significantly higher in NSCLC than in COPD, which was further verified by the immunohistochemistry. In addition, the high expression levels of H2AFX, MCM2, MCM7, and POLD1 correlate with poor prognosis of lung adenocarcinoma (LUAD). The Cox regression prognostic risk model showed the similar results and the predictive ability of this model is independent of other clinical variables. Conclusions: This study revealed several key modules that closely relate to NSCLC with underlying disease COPD, which provide a deeper understanding of the potential mechanisms underlying the malignant development from COPD to NSCLC. This study provides valuable prognostic factors in high-risk lung cancer patients with COPD.

Alterations of mitochondrial DNA (mtDNA) have been identified in several types of solid tumor. However, to the best of our knowledge, the clinical significance of plasma mtDNA content in lung cancer remains unknown. Thus, the current study explored the diagnostic and prognostic value of plasma mtDNA quantification in patients with lung cancer. Plasma mtDNA copy numbers of patients with lung cancer (n=128) and healthy individuals (n=107) were quantified by quantitative polymerase chain reaction. Plasma mtDNA copy numbers in patients and healthy controls were 0.89×104 and 1.37×104 copies/µl, respectively (P0.05). Plasma mtDNA facilitated the detection of lung cancer at a threshold of 1.19×104 copies/µl with a sensitivity of 71.1% and specificity of 70.1%, as determined by receiver operating characteristic curve analysis. Advanced stage (III and IV) patients with a lower mtDNA copy number (cutoff: 1.02×104 copies/µl) tended to exhibit poorer prognosis (P

Toll-like receptor 5 (TLR5) is a pattern recognition receptor and plays key roles in inflammatory responses against pathogen infection. Recent evidence suggests that TLR5 is expressed in a wide variety of tumors and exhibits either pro-tumor or anti-tumor activities. In this study, we explored expression of TLR5 in the context of non-small-cell lung cancer (NSCLC) and evaluated the effects of TLR5 signaling in NSCLC cells. The lung carcinoma samples were collected from 113 patients diagnosed as NSCLC at Tumor Hospital of Xiangya School of Medicine from January 2005 to December 2008. Immunohistochemistry was performed for TLR5 and the protein expression score was quantified using an established scoring system. Kaplan–Meier survival curves were generated for disease-free survival (DFS) and overall survival (OS) in all patients. TLR5 expression levels were correlated with DFS and OS using univariate and multivariate Cox regression analysis. Expression and subcellular localization of TLR5 were analyzed in NSCLC cell lines including SPC-A1, A549, H1975, and H1299 cells. Activation of TLR5 signaling pathway by flagellin was characterized by western blotting. Effects of flagellin on NSCLC cell proliferation, anchorage-independent growth, migration, and invasion were analyzed by BrdU incorporation assay, soft agar colony formation assay, wound-healing migration assay, and transwell invasion assay, respectively. High expression of TLR5 was significantly associated with better prognosis in patients with NSCLC. We further demonstrated that activation of TLR5 by flagellin in NSCLC cells inhibited cell proliferation, migration, and invasion in vitro. TLR5 may serve as a potential therapeutic target in NSCLC patients.

e20534 Background: While tumor genotyping is the standard treatment for patients with non-small cell lung cancer (NSCLC), spatial and temporal tumor heterogeneity and insufficient specimens can lead to limitations in the use of tissue-based sequencing. Circulating tumor DNA (ctDNA) fully encompasses tumor-specific sequence alterations and offers an alternative to tissue sample biopsies. The aim of the study was to evaluate whether the frequency of multiple genomic alterations observed following ctDNA sequencing was similar to that observed following tissue sequencing in NSCLC. Methods: A total of 99 NSCLC patients were enrolled in this study, including 40 tissue and 59 plasma samples. All kinds of variants of oncogenic drivers in NSCLC were identified by next-generation sequencing (NGS) with Acornmed panel. Results: The frequencies of genetic alterations detected in ctDNA were significantly correlated to those detected via tissue profiling (Spearman’s r = 0.812, P = 0.022). Genomic data revealed significant mutual exclusivity between alterations in epidermal growth factor receptor ( EGFR) and tumor protein 53 ( TP53; P = 0.020) and between those in EGFR and Kirsten rat sarcoma viral oncogene homolog ( KRAS; P = 0.008), as well as potential mutual exclusivity between alterations in EGFR and Erb-B2 receptor tyrosine kinase 2 ( ERBB2; P = 0.059). Furthermore, the EGFR mutant allele frequency (MAF) was strongly correlated with the TP53 MAF in individual tumors (Spearman’s r = 0.773, P = 0.005), and there was a marked difference in the EGFR MAF between patients with and without the TP53 mutation (P = 0.001). Levels of the tumor serum marker CA242 in patients with ctDNA-detectable mutations were higher than those in patients without ctDNA-detectable mutations. Conclusions: This study provides a better understanding of the spectra of genomic alterations detected by tissue and plasma ctDNA assays in Chinese patients with NSCLC. The present data also highlights the importance of tissue and plasma ctDNA screening by NGS to guide personalized therapy and promote the clinical management of NSCLC patients.