Profile of epigenetic mechanisms in lung tumors of patients with underlying chronic respiratory conditions

MiRNA-210 is involved in cigarette smoke extract-induced apoptosis of MLE-12 via the Shh signaling pathway

INTRODUCTION

The aim of the study is the regulatory effect of MicroRNA-210 (MiR-210) on cigarette smoke extract (CSE)-induced mouse lung epithelial type II cells (MLE-12) apoptosis and determine whether the MiR-210 is involved in cigarette smoke extract-induced apoptosis of MLE-12 via Shh signaling pathway.

METHODS

Expression of MiR-210 in CSE-induced MLE-12 was assessed by qRT-PCR. The emphysema mouse model and MiR-210 knockdown mice were each established by inhaling cigarette smoke or intratracheal lentiviral vector instillation. The Sonic hedgehog (Shh), Ptch1, Gli1, B-cell lymphoma-2 (Bcl-2), and Caspase 3 protein expressions were detected by Western blotting. mRNA expressions of MiR-210, Shh, Ptch1, and Gli1 were measured using quantitative real-time polymerase chain reaction (qRT-PCR). Apoptotic ratios in mice and CSE-induced HPVEC were assessed using TUNEL (terminal deoxynucleotidyl transferase dUTP nick end labeling) assays and flow cytometry.

RESULTS

Our results showed that MiR-210 mRNA levels were significantly down-regulated in the CSE-induced MLE 12. MLE 12 apoptosis with down-regulated Shh, Ptch1, Gli1, and Bcl-2 expression, increased Caspase 3 expression in the emphysema mouse model and CSE-induced MLE 12. Knockdown MiR-210 can facilitate cell apoptosis and emphysema via the Shh signaling pathway in mice. In vitro, MiR-210 can attenuate the apoptosis of CSE-exposed MLE 12. Moreover, MiR-210 regulated the Shh pathway and promoted its expression.

CONCLUSIONS

MiRNA-210 is involved in cigarette smoke extract-induced apoptosis of MLE-12 via the Shh signaling pathway. The present study reveals that MiRNA-210 may be a key regulator of cellular apoptosis and could be explored as a potential therapeutic target in the future.

International expert consensus on diagnosis and treatment of lung cancer complicated by chronic obstructive pulmonary disease

BACKGROUND

Lung cancer combined by chronic obstructive pulmonary disease (LC-COPD) is a common comorbidity and their interaction with each other poses significant clinical challenges. However, there is a lack of well-established consensus on the diagnosis and treatment of LC-COPD.

METHODS

A panel of experts, comprising specialists in oncology, respiratory medicine, radiology, interventional medicine, and thoracic surgery, was convened. The panel was presented with a comprehensive review of the current evidence pertaining to LC-COPD. After thorough discussions, the panel reached a consensus on 17 recommendations with over 70% agreement in voting to enhance the management of LC-COPD and optimize the care of these patients.

RESULTS

The 17 statements focused on pathogenic mechanisms (n=2), general strategies (n=4), and clinical application in COPD (n=2) and lung cancer (n=9) were developed and modified. These statements provide guidance on early screening and treatment selection of LC-COPD, the interplay of lung cancer and COPD on treatment, and considerations during treatment. This consensus also emphasizes patient-centered and personalized treatment in the management of LC-COPD.

CONCLUSIONS

The consensus highlights the need for concurrent treatment for both lung cancer and COPD in LC-COPD patients, while being mindful of the mutual influence of the two conditions on treatment and monitoring for adverse reactions.

Mechanisms Contributing to the Comorbidity of COPD and Lung Cancer

Lung cancer and chronic obstructive pulmonary disease (COPD) often co-occur, and individuals with COPD are at a higher risk of developing lung cancer. While the underlying mechanism for this risk is not well understood, its major contributing factors have been proposed to include genomic, immune, and microenvironment dysregulation. Here, we review the evidence and significant studies that explore the mechanisms underlying the heightened lung cancer risk in people with COPD. Genetic and epigenetic changes, as well as the aberrant expression of non-coding RNAs, predispose the lung epithelium to carcinogenesis by altering the expression of cancer- and immune-related genes. Oxidative stress generated by tobacco smoking plays a role in reducing genomic integrity, promoting epithelial-mesenchymal-transition, and generating a chronic inflammatory environment. This leads to abnormal immune responses that promote cancer development, though not all smokers develop lung cancer. Sex differences in the metabolism of tobacco smoke predispose females to developing COPD and accumulating damage from oxidative stress that poses a risk for the development of lung cancer. Dysregulation of the lung microenvironment and microbiome contributes to chronic inflammation, which is observed in COPD and known to facilitate cancer initiation in various tumor types. Further, there is a need to better characterize and identify the proportion of individuals with COPD who are at a high risk for developing lung cancer. We evaluate possible novel and individualized screening strategies, including biomarkers identified in genetic studies and exhaled breath condensate analysis. We also discuss the use of corticosteroids and statins as chemopreventive agents to prevent lung cancer. It is crucial that we optimize the current methods for the early detection and management of lung cancer and COPD in order to improve the health outcomes for a large affected population.

Non-Coding RNAs in Airway Diseases: A Brief Overview of Recent Data

Inflammation of the human lung is mediated in response to different stimuli (e.g., physical, radioactive, infective, pro-allergenic, or toxic) such as cigarette smoke and environmental pollutants. These stimuli often promote an increase in different inflammatory activities in the airways, manifesting themselves as chronic diseases (e.g., allergic airway diseases, asthma chronic bronchitis/chronic obstructive pulmonary disease, or even lung cancer). Non-coding RNA (ncRNAs) are single-stranded RNA molecules of few nucleotides that regulate the gene expression involved in many cellular processes. ncRNA are molecules typically involved in the reduction of translation and stability of the genes of mRNAs s. They regulate many biological aspects such as cellular growth, proliferation, differentiation, regulation of cell cycle, aging, apoptosis, metabolism, and neuronal patterning, and influence a wide range of biologic processes essential for the maintenance of cellular homeostasis. The relevance of ncRNAs in the pathogenetic mechanisms of respiratory diseases has been widely established and in the last decade many papers were published. However, once their importance is established in pathogenetic mechanisms, it becomes important to further deepen the research in this direction. In this review we describe several of most recent knowledge concerning ncRNA (overall miRNAs) expression and activities in the lung.

Gene expression profile of epithelial-mesenchymal transition in tumors of patients with nsclc: the influence of COPD

Epithelial–mesenchymal transition (EMT) is involved in the pathophysiology of lung cancer (LC) and COPD, and the latter is an important risk factor for LC. We hypothesised that the EMT gene expression profile and signalling cascade may differ in LC patients with COPD from those with no respiratory diseases. In lung tumour specimens obtained through video-assisted thoracoscopic surgery from LC (n=20, control group) and LC-COPD patients (n=30), gene expression (quantitative real-time PCR amplification) of EMT markers SMAD3, SMAD4, ZEB2, TWIST1, SNAI1, ICAM1, VIM, CDH2, MMP1 and MMP9 was detected. In lung tumours of LC-COPD compared to LC patients, gene expression of SMAD3, SMAD4, ZEB2 and CDH2 significantly declined, while no significant differences were detected for the other analysed markers. A significant correlation was found between pack-years (smoking burden) and SMAD3 gene expression among LC-COPD patients. LC-COPD patients exhibited mild-to-moderate airway obstruction and a significant reduction in diffusion capacity compared to LC patients. In lung tumour samples of patients with COPD, several markers of EMT expression, namely SMAD3, SMAD4, ZEB2 and CDH2, were differentially expressed suggesting that these markers are likely to play a role in the regulation of EMT in patients with this respiratory disease. Cigarette smoke did not seem to influence the expression of EMT markers in this study. These results have potential clinical implications in the management of patients with LC, particularly in those with underlying respiratory diseases.

The downregulation of the epithelial–mesenchymal transition repressor SMAD pathway may favour a pro-tumoural micro-environment in patients with chronic airway diseases, namely COPD, which could be targeted therapeuticallyhttps://bit.ly/39oXnoG

EFNA3 as a predictor of clinical prognosis and immune checkpoint therapy efficacy in patients with lung adenocarcinoma

BACKGROUND

Ephrin receptors (Eph) and their ligands, called ephrins, function in various disease processes. However, the expression level and prognostic value of Eph/ephrins in lung adenocarcinoma (LUAD) are still unclear.

METHODS

The Oncomine and GEPIA databases were used to explore the differential expression of Eph/ephrins in LUAD. Kaplan-Meier plotter was selected to explore the prognostic value of Eph/ephrins. The cBioPortal database was used to analyze the genetic variation of the EFNA3 gene. Immunohistochemistry was used to analyze the expression level and clinical value of ephrin-A3 protein in clinical LUAD tissue. Weighted coexpression network analysis (WGCNA) and gene set enrichment analysis (GSEA) identified the potential regulatory mechanism of EFNA3. CCK-8 assays and colony-forming experiments were used to investigate whether EFNA3 can regulate cell proliferation ability in LUAD. Analysis of lactate, ATP, and glucose uptake levels was used to explore the effect of EFNA3 on glycolysis ability. In addition, we investigated the relationship between EFNA3 and tumor infiltrating immune cells (TIICs). Finally, the potential immunotherapy response prediction value of EFNA3 was also explored.

RESULTS

In this study, we found that EFNA3 expression was significantly correlated with both overall survival (OS) and progression-free survival (PFS) in LUAD patients based on a comprehensive analysis of the Eph/Ephrin family. Next, the expression of the EFNA3 protein was increased in LUAD tissues and was designated an independent prognostic risk factor. Mechanistically, EFNA3 may be involved in nuclear division, synaptic function, and ion channel activity-related pathways. In vitro experiments confirmed the role of EFNA3 in promoting LUAD cells and showed that it could regulate glycolytic capacity. Moreover, EFNA3 was negatively associated with immunity, stromal infiltration, and several TIICs. Finally, EFNA3 was found to be positively related to multiple immunotherapy biomarkers.

CONCLUSIONS

In conclusion, increased EFNA3 in LUAD patients predicted worse clinical prognosis, promoted LUAD cell proliferation and glycolysis ability, and was related to immunotherapy response.

Systemic Profiles of microRNAs, Redox Balance, and Inflammation in Lung Cancer Patients: Influence of COPD

Lung cancer (LC) risk increases in patients with chronic respiratory diseases (COPD). MicroRNAs and redox imbalance are involved in lung tumorigenesis in COPD patients. Whether systemic alterations of those events may also take place in LC patients remains unknown. Our objectives were to assess the plasma levels of microRNAs, redox balance, and cytokines in LC patients with/without COPD. MicroRNAs (RT-PCR) involved in LC, oxidized DNA, MDA-protein adducts, GSH, TEAC, VEGF, and TGF-beta (ELISA) were quantified in plasma samples from non-LC controls (n = 45), LC-only patients (n = 32), and LC-COPD patients (n = 91). In LC-COPD patients compared to controls and LC-only, MDA-protein adduct levels increased, while those of GSH decreased, and two patterns of plasma microRNA were detected. In both LC patient groups, miR-451 expression was downregulated, while those of microRNA-let7c were upregulated, and levels of TEAC and TGF-beta increased compared to the controls. Correlations were found between clinical and biological variables. A differential expression profile of microRNAs was detected in patients with LC. Moreover, in LC patients with COPD, plasma oxidative stress levels increased, whereas those of GSH declined. Systemic oxidative and antioxidant markers are differentially expressed in LC patients with respiratory diseases, thus implying its contribution to the pathogenesis of tumorigenesis in these patients.

Chronic Obstructive Pulmonary Disease: Epidemiology, Biomarkers, and Paving the Way to Lung Cancer

Chronic obstructive pulmonary disease (COPD), the frequently fatal pathology of the respiratory tract, accounts for half a billion cases globally. COPD manifests via chronic inflammatory response to irritants, frequently to tobacco smoke. The progression of COPD from early onset to advanced disease leads to the loss of the alveolar wall, pulmonary hypertension, and fibrosis of the respiratory epithelium. Here, we focus on the epidemiology, progression, and biomarkers of COPD with a particular connection to lung cancer. Dissecting the cellular and molecular players in the progression of the disease, we aim to shed light on the role of smoking, which is responsible for the disease, or at least for the more severe symptoms and worse patient outcomes. We summarize the inflammatory conditions, as well as the role of EMT and fibroblasts in establishing a cancer-prone microenvironment, i.e., the soil for ‘COPD-derived’ lung cancer. We highlight that the major health problem of COPD can be alleviated via smoking cessation, early diagnosis, and abandonment of the usage of biomass fuels on a global basis.

The Expression Patterns of BECN1, LAMP2, and PINK1 Genes in Colorectal Cancer Are Potentially Regulated by Micrornas and CpG Islands: An In Silico Study

Background: Autophagy plays a dual role of tumor suppression and tumor promotion in colorectal cancer. The study aimed to find those microRNAs (miRNAs) important in BECN1, LAMP2, and PINK1 regulation and to determine the possible role of the epigenetic changes in examined colorectal cancer using an in silico approach. Methods: A total of 44 pairs of surgically removed tumors at clinical stages I‒IV and healthy samples (marginal tissues) from patients’ guts were analyzed. Analysis of the obtained results was conducted using the PL-Grid Infrastructure and Statistica 12.0 program. The miRNAs and CpG islands were estimated using the microrna.org database and MethPrimer program. Results: The autophagy-related genes were shown to be able to be regulated by miRNAs (BECN1—49 mRNA, LAMP2—62 mRNA, PINK1—6 mRNA). It was observed that promotion regions containing at least one CpG region were present in the sequence of each gene. Conclusions: The in silico analysis performed allowed us to determine the possible role of epigenetic mechanisms of regulation gene expression, which may be an interesting therapeutic target in the treatment of colorectal cancer.

Let-7c regulated epithelial-mesenchymal transition leads to osimertinib resistance in NSCLC cells with EGFR T790M mutations

Epidermal growth factor receptor- tyrosine kinase inhibitors (EGFR-TKIs) have shown promise against non-small cell lung cancers (NSCLCs) in clinics but the utility is often short-lived because of T790M mutations in EGFR that help evade TKIs’ action. Osimertinib is the third and latest generation TKI that targets EGFRs with T790M mutations. However, there are already reports on acquired resistance against Osimertinib. Recent work has revealed the role that miRNAs, particularly tumor suppressor let-7c, play in the invasiveness and acquired resistance of NSCLCs, but the mechanistic details, particularly in Osimertinib resistance, remain elusive. Using two cells lines, H1975 (endogenous T790M mutation) and HCC827-T790M (with acquired T790M mutation), we found that let-7c is a regulator of EMT, as well as it affects CSC phenotype. In both the cell lines, transfection with pre-let-7c led to reversal of EMT as studied through EMT markers e-cadherin and ZEB1. This resulted in reduced proliferation and invasion. Conversely, reduced expression of let-7c through anti-let-7c transfections significantly increased proliferation and invasion of lung cancer cells. Expression of let-7c was functionally relevant as EMT correlated with resistance to Osimertinib. High let-7c expression reversed EMT and made cells sensitive to Osimertinib, and vice versa. WNT1 and TCF-4 were found to be two targets of let-7c which were epigenetic suppressed by let-7c through increased methylation. In vivo, pre-let-7c inhibited while anti-let-7c potentiated tumor growth and WNT1 and TCF-4 were downregulated in xenografts with pre-let-7c. Silencing of both WNT1 and TCF-4 resulted in potentiation of Osimertinib action. Our results suggest an important role of let-7c in regulating EMT and the resulting Osimertinib resistance in T790M NSCLCs. More clinical studies need to be performed to fully understand the translational relevance of this novel mechanism.

Immune Cell Subtypes and Cytokines in Lung Tumor Microenvironment: Influence of COPD

Background: The immune microenvironment plays a role in tumorigenesis. Chronic Obstructive Pulmonary Disease (COPD) is an independent risk factor for lung cancer (LC). We hypothesized that immune profile characterized by T regulatory (Treg), natural killer (NK), and plasma cells, as well as interleukin (IL)-10 and interferon-gamma, may differ within tumors of LC patients with/without COPD. Methods: Treg (anti-CD3 and anti-forkhead boxP3 antibodies), NK (anti-NCR1 antibody), IgG (anti-CD138-IgG antibody), IgA (anti-CD138-IgA antibody) using immunohistochemistry, and both IL-10 and interferon-gamma (ELISA) were quantified in tumor and non-tumor specimens (thoracotomy for lung tumor resection) from 33 LC–COPD patients and 20 LC-only patients. Results: Immune profile in tumor versus non-tumor specimens: Treg cell counts significantly increased in tumors of both LC and LC–COPD patients, while in tumors of the latter group, IgG-secreting plasma cells significantly decreased and IL-10 increased. No significant differences were seen in levels of NK cells, IgA-secreting cells, IgA/IgG, or interferon-gamma. Immune profile in tumors of LC–COPD versus LC: No significant differences were observed in tumors between LC–COPD and LC patients for any study marker. Conclusions: Immune cell subtypes and cytokines are differentially expressed in lung tumors, and the presence of COPD elicited a decline in IgG-secreting plasma cell levels but not in other cell types.

Chronic obstructive pulmonary disease (COPD) and lung cancer: common pathways for pathogenesis

Chronic obstructive pulmonary disease (COPD) and lung cancer comprise the leading causes of lung disease-related mortality worldwide. Exposure to tobacco smoke is a mutual aetiology underlying the two diseases, accounting for almost 90% of cases. There is accumulating evidence supporting the role of immune dysfunction, the lung microbiome, extracellular vesicles and underlying genetic susceptibility in the development of COPD and lung cancer. Further, epigenetic factors, involving DNA methylation and microRNA expression, have been implicated in both diseases. Chronic inflammation is a key feature of COPD and could be a potential driver of lung cancer development. Using next generation technologies, further studies investigating the genomics, epigenetics and gene-environment interaction in key molecular pathways will continue to elucidate the pathogenic mechanisms underlying the development of COPD and lung cancer, and contribute to the development of novel diagnostic and prognostic tools for early intervention and personalised therapeutic strategies.

Immunotherapy with Monoclonal Antibodies in Lung Cancer of Mice: Oxidative Stress and Other Biological Events

Background: Lung cancer (LC) is a major leading cause of death worldwide. Immunomodulators that target several immune mechanisms have proven to reduce tumor burden in experimental models through induction of the immune microenvironment. We hypothesized that other biological mechanisms may also favor tumor burden reduction in lung cancer-bearing mice treated with immunomodulators. Methods: Tumor weight, area, T cells and tumor growth (immunohistochemistry), oxidative stress, apoptosis, autophagy, and signaling (NF-κB and sirtuin-1) markers were analyzed (immunoblotting) in subcutaneous tumor of BALB/c mice injected with LP07 adenocarcinoma cells treated with monoclonal antibodies (CD-137, CTLA-4, PD-1, and CD-19, N = 9/group) and non-treated control animals. Results: Compared to non-treated cancer mice, in tumors of monoclonal-treated animals, tumor area and weight and ki-67 were significantly reduced, while T cell counts, oxidative stress, apoptosis, autophagy, activated p65, and sirtuin-1 markers were increased. Conclusions: Immunomodulators elicited a reduction in tumor burden (reduced tumor size and weight) through decreased tumor proliferation and increased oxidative stress, apoptosis, autophagy, and signaling markers, which may have interfered with the immune profile of the tumor microenvironment. Future research should be devoted to the elucidation of the specific contribution of each biological mechanism to the reduced tumor burden.

Morin Protects Human Respiratory Cells from PM2.5 Induced Genotoxicity by Mitigating ROS and Reverting Altered miRNA Expression

Chronic fine particulate matter (PM2.5) exposure causes oxidative stress and leads to many diseases in human like respiratory and cardiovascular disorders, and lung cancer. It is known that toxic responses elicited by PM2.5 particles depend on its physical and chemical characteristics that are greatly influenced by the source. Dietary polyphenolic compounds that possess antioxidant and free radical scavenging properties could be used for therapeutic or preventive approaches against air pollution related health hazards. This study evaluates characteristics and toxicity of PM2.5 collected from rural, urban, industrial, and traffic regions in and around Coimbatore City, Tamilnadu, India. Traffic PM2.5 particles contained higher amounts of metals and polycyclic aromatic hydrocarbons (PAHs). It also possessed higher levels of oxidative potential, induced more intracellular reactive oxygen species (ROS), and caused more levels of cell death and DNA damage in human respiratory cells. Its exposure up regulated DNA damage response related miR222, miR210, miR101, miR34a, and miR93 and MycN and suppressed Rad52. Pre-treatment with morin significantly decreased the PM2.5 induced toxicity and conferred protection against PM2.5 induced altered miRNA expression. Results of this study showed that cytoprotective effect of morin is due to its antioxidative and free radical scavenging activity.

Association between circulating microRNA-126 expression level and tumour necrosis factor alpha in healthy smokers

Introduction: Smoking contributes to the death of a million people worldwide each year. Smokers experience an alteration in tumour necrosis factor-alpha (TNF-α), and the risk of expected lung cancer. The study aimed at investigating the expression levels of mir-126 and mir-124, as well as TNF-α as possible biomarkers of expected smoking-related diseases. Methods: Twenty-five male smokers' age and sex-matched with 25 non-smokers were recruited for the present study. Plasma expression levels of mir-126 and mir-124 were evaluated using quantitative real-time PCR. Lipid profile, TNF-α, interleukin-6 and C-reactive protein were assessed in plasma of each participant. Results: Plasma miR-126 was statistically down-regulated in smokers relative to non-smokers; however, mir-124 did not show any significant changes between groups. Among the measured parameters, mir-126 and tumour necrosis factor alpha (TNF-α) displayed a good discrimination and sensitivity between smokers and non-smokers (AUC = 0.809 (95% CI: 0.668-0.95; p < 0.001) and 0.742(95% CI: 0.584-0.9; p < 0.01), respectively. Also, the combined evaluation of miR-126 and TNF-α levels showed high discrimination (AUC= 0.889 (95% CI: 0.779-1.00; p < 0.0001), sensitivity = 85%, and specificity = 80% in the diagnosis of smokers with non-smokers. Conclusions: MiR-126 and TNF-α are potential biomarkers of smoking-related diseases and are important in assessing the expected tobacco-related harm.

Epigenetic impacts of maternal tobacco and e-vapour exposure on the offspring lung

In utero exposure to tobacco products, whether maternal or environmental, have harmful effects on first neonatal and later adult respiratory outcomes. These effects have been shown to persist across subsequent generations, regardless of the offsprings' smoking habits. Established epigenetic modifications induced by in utero exposure are postulated as the mechanism underlying the inherited poor respiratory outcomes. As e-cigarette use is on the rise, their potential to induce similar functional respiratory deficits underpinned by an alteration in the foetal epigenome needs to be explored. This review will focus on the functional and epigenetic impact of in utero exposure to maternal cigarette smoke, maternal environmental tobacco smoke, environmental tobacco smoke and e-cigarette vapour on foetal respiratory outcomes.