MiRNAs and Microbiota in Non-Small Cell Lung Cancer (NSCLC): Implications in Pathogenesis and Potential Role in Predicting Response to ICI Treatment.

Lung cancer (LC) is one of the most prevalent cancers in both men and women and today is still characterized by high mortality and lethality. Several biomarkers have been identified for evaluating the prognosis of non-small cell lung cancer (NSCLC) patients and selecting the most effective therapeutic strategy for these patients. The introduction of innovative targeted therapies and immunotherapy with immune checkpoint inhibitors (ICIs) for the treatment of NSCLC both in advanced stages and, more recently, also in early stages, has revolutionized and significantly improved the therapeutic scenario for these patients. Promising evidence has also been shown by analyzing both micro-RNAs (miRNAs) and the lung/gut microbiota. MiRNAs belong to the large family of non-coding RNAs and play a role in the modulation of several key mechanisms in cells such as proliferation, differentiation, inflammation, and apoptosis. On the other hand, the microbiota (a group of several microorganisms found in human orgasms such as the gut and lungs and mainly composed by bacteria) plays a key role in the modulation of inflammation and, in particular, in the immune response. Some data have shown that the microbiota and the related microbiome can modulate miRNAs expression and vice versa by regulating several intracellular signaling pathways that are known to play a role in the pathogenesis of lung cancer. This evidence suggests that this axis is key to predicting the prognosis and effectiveness of ICIs in NSCLC treatment and could represent a new target in the treatment of NSCLC. In this review, we highlight the most recent evidence and data regarding the role of both miRNAs and the lung/gut microbiome in the prediction of prognosis and response to ICI treatment, focusing on the link between miRNAs and the microbiome. A new potential interaction based on the underlying modulated intracellular signaling pathways is also shown.

Poxviridae Pneumonia.

Poxviridae family includes several viruses that infecting humans usually causes skin lesions only, but in some cases their clinical course is complicated by viral pneumonia (with or without bacterial superinfections). Historically variola virus has been the poxviridae most frequently associated with the development of pneumonia with many large outbreaks worldwide before its eradication in 1980. It is still considered a biological threat for its potential in biological warfare and bioterrorism. Smallpox pneumonia can be severe with the onset of acute respiratory distress syndrome (ARDS) and death. Vaccinia virus, used for vaccination against smallpox exceptionally, in immunocompromised patients, can induce generalized (with also lung involvement) severe disease after vaccination. MPXV virus occasionally can cause pneumonia particularly in immunocompromised patients. The pathophysiology of poxviridae pneumonia is still an area of active research; however, in animal models these viruses can cause both direct damage to the lower airways epithelium and a hyperinflammatory syndrome, like a cytokine storm. Multiple mechanisms of immune evasion have also been described. The treatment of poxviridae pneumonia is mainly based on careful supportive care. Despite the absence of randomized clinical trials in patients with poxviridae pneumonia there are antiviral drugs, such as tecovirimat, cidofovir and brincidofovir, FDA-approved for use in smallpox and also available under an expanded access protocol for treatment of MPXV. There are 2 (replication-deficient modified vaccinia Ankara and replication-competent vaccinia virus) smallpox vaccines FDA-approved with the first one also approved for prevention of MPXV in adults that are at high risk of infection.

Circulating biomarkers as predictors of response to immune checkpoint inhibitors in NSCLC: Are we on the right path?

Immune checkpoints inhibitors (ICIs) have markedly improved the therapeutic management of advanced NSCLC and, more recently, they have demonstrated efficacy also in the early-stage disease. Despite better survival outcomes with ICIs compared to standard chemotherapy, a large proportion of patients can derive limited clinical benefit from these agents. So far, few predictive biomarkers, including the programmed death-ligand 1 (PD-L1), have been introduced in clinical practice. Therefore, there is an urgent need to identify novel biomarkers to select patients for immunotherapy, to improve efficacy and avoid unnecessary toxicity. A deeper understanding of the mechanisms involved in antitumor immunity and advances in the field of liquid biopsy have led to the identification of a wide range of circulating biomarkers that could potentially predict response to immunotherapy. Herein, we provide an updated overview of these circulating biomarkers, focusing on emerging data from clinical studies and describing modern technologies used for their detection.

IL-33 immunohistochemical pattern of expression in neoplastic and nonneoplastic peripheral lung tissues of stage 1 o 2 lung adenocarcinoma.

IL-33 is a multifaceted cytokine, plays a pivotal role in various biological processes, making it a subject of extensive research and intrigue in the field of immunology. This cytokine acts as a key regulator, effectively putting the brakes on proinflammatory nuclear factor-kappa B (NF-κB), thereby modulating chromatin compaction by promoting nucleosome-to-nucleosome interactions. IL-33's influence extends to the realm of innate and acquired immunity through its binding to the membrane-bound ST2 molecule (ST2L) of the IL-33R complex, which is expressed on various immune cells, such as Th2 cells, mast cells, natural killer cells, myeloid cells, and dendritic cells. IL-33's role in inflammation is far from one-dimensional, as it has been found to have a dual role in inflammatory disorders. In the quest to understand the origins of IL-33, immunohistochemical examination of lung tissue samples from patients with adenocarcinoma could shed light on its presence in bronchial epithelial and vascular endothelial cells, in lung tissue cancerous lesions. For this reason, we conducted a pilot study about the immunohistochemical expression of IL-33 in surgical specimens of stage 1 o 2 lung adenocarcinoma received after lung resection surgery.Our results demonstrated that patients had nuclear IL-33 immunopositivity in the alveolar pneumocytes of the normal lung tissue at the periphery of lung adenocarcinoma specimen. Note the evident negativity of the neoplastic adenocarcinoma cells. Other data showed IL-33 nuclear immunoexpression in endothelial cells of intratumoral vascular structures.This finding could indicate that IL-33 might be involved in regulating blood vessel formation and maintenance within the tumor, which is a critical factor in tumor growth and progression.The presence of IL-33 in normal lung tissue and intratumoral vascular structures may be related to its physiological functions in these contexts, while its absence in neoplastic adenocarcinoma cells could indicate a potential loss of regulatory control, which might have implications for the development and progression of the tumor.

Pre-clinical lung squamous cell carcinoma mouse models to identify novel biomarkers and therapeutic interventions.

Primary lung carcinoma or lung cancer (LC) is classified into small-cell or non-small-cell (NSCLC) lung carcinoma. Lung squamous cell carcinoma (LSCC) is the second most common subtype of NSCLC responsible for 30% of all LCs, and its survival remains low with only 24% of patients living for five years or longer post-diagnosis primarily due to the advanced stage of tumors at the time of diagnosis. The pathogenesis of LSCC is still poorly understood and has hampered the development of effective diagnostics and therapies. This review highlights the known risk factors, genetic and epigenetic alterations, miRNA biomarkers linked to the development and diagnosis of LSCC and the lack of therapeutic strategies to target specifically LSCC. We will also discuss existing animal models of LSCC including carcinogen induced, transgenic and xenograft mouse models, and their advantages and limitations along with the chemopreventive studies and molecular studies conducted using them. The importance of developing new and improved mouse models will also be discussed that will provide further insights into the initiation and progression of LSCC, and enable the identification of new biomarkers and therapeutic targets.

Expression of targets of the RNA-binding protein AUF-1 in human airway epithelium indicates its role in cellular senescence and inflammation.

Introduction: The RNA-binding protein AU-rich-element factor-1 (AUF-1) participates to posttranscriptional regulation of genes involved in inflammation and cellular senescence, two pathogenic mechanisms of chronic obstructive pulmonary disease (COPD). Decreased AUF-1 expression was described in bronchiolar epithelium of COPD patients versus controls and in vitro cytokine- and cigarette smoke-challenged human airway epithelial cells, prompting the identification of epithelial AUF-1-targeted transcripts and function, and investigation on the mechanism of its loss. Results: RNA immunoprecipitation-sequencing (RIP-Seq) identified, in the human airway epithelial cell line BEAS-2B, 494 AUF-1-bound mRNAs enriched in their 3'-untranslated regions for a Guanine-Cytosine (GC)-rich binding motif. AUF-1 association with selected transcripts and with a synthetic GC-rich motif were validated by biotin pulldown. AUF-1-targets' steady-state levels were equally affected by partial or near-total AUF-1 loss induced by cytomix (TNFα/IL1ß/IFNγ/10 nM each) and siRNA, respectively, with differential transcript decay rates. Cytomix-mediated decrease in AUF-1 levels in BEAS-2B and primary human small-airways epithelium (HSAEC) was replicated by treatment with the senescence- inducer compound etoposide and associated with readouts of cell-cycle arrest, increase in lysosomal damage and senescence-associated secretory phenotype (SASP) factors, and with AUF-1 transfer in extracellular vesicles, detected by transmission electron microscopy and immunoblotting. Extensive in-silico and genome ontology analysis found, consistent with AUF-1 functions, enriched RIP-Seq-derived AUF-1-targets in COPD-related pathways involved in inflammation, senescence, gene regulation and also in the public SASP proteome atlas; AUF-1 target signature was also significantly represented in multiple transcriptomic COPD databases generated from primary HSAEC, from lung tissue and from single-cell RNA-sequencing, displaying a predominant downregulation of expression. Discussion: Loss of intracellular AUF-1 may alter posttranscriptional regulation of targets particularly relevant for protection of genomic integrity and gene regulation, thus concurring to airway epithelial inflammatory responses related to oxidative stress and accelerated aging. Exosomal-associated AUF-1 may in turn preserve bound RNA targets and sustain their function, participating to spreading of inflammation and senescence to neighbouring cells.

Cellular and molecular features of COVID-19 associated ARDS: therapeutic relevance.

The severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) infection can be asymptomatic or cause a disease (COVID-19) characterized by different levels of severity. The main cause of severe COVID-19 and death is represented by acute (or acute on chronic) respiratory failure and acute respiratory distress syndrome (ARDS), often requiring hospital admission and ventilator support.The molecular pathogenesis of COVID-19-related ARDS (by now termed c-ARDS) is still poorly understood. In this review we will discuss the genetic susceptibility to COVID-19, the pathogenesis and the local and systemic biomarkers correlated with c-ARDS and the therapeutic options that target the cell signalling pathways of c-ARDS.

RNA-Binding Proteins as a Molecular Link between COPD and Lung Cancer.

Chronic obstructive pulmonary disease (COPD) represents an independent risk factor for lung cancer development. Accelerated cell senescence, induced by oxidative stress and inflammation, is a common pathogenic determinant of both COPD and lung cancer. The post transcriptional regulation of genes involved in these processes is finely regulated by RNA-binding proteins (RBPs), which regulate mRNA turnover, subcellular localization, splicing and translation. Multiple pro-inflammatory mediators (including cytokines, chemokines, proteins, growth factors and others), responsible of lung microenvironment alteration, are regulated by RBPs. Several mouse models have shown the implication of RBPs in multiple mechanisms that sustain chronic inflammation and neoplastic transformation. However, further studies are required to clarify the role of RBPs in the pathogenic mechanisms shared by lung cancer and COPD, in order to identify novel biomarkers and therapeutic targets. This review will therefore focus on the studies collectively indicating the role of RBPs in oxidative stress and chronic inflammation as common pathogenic mechanisms shared by lung cancer and COPD.

Decreased humoral immune response in the bronchi of rapid decliners with chronic obstructive pulmonary disease.

BACKGROUND: Identification of COPD patients with a rapid decline in FEV1 is of particular interest for prognostic and therapeutic reasons. OBJECTIVE: To determine the expression of markers of inflammation in COPD patients with rapid functional decline in comparison to slow or no decliners. METHODS: In COPD patients monitored for at least 3 years (mean ± SD: 5.8 ± 3 years) for lung functional decline, the expression and localization of inflammatory markers was measured in bronchial biopsies of patients with no lung functional decline (FEV1% + 30 ± 43 ml/year, n = 21), slow (FEV1% ml/year, - 40 ± 19, n = 14) and rapid decline (FEV1% ml/year, - 112 ± 53, n = 15) using immunohistochemistry. ELISA test was used for polymeric immunoglobulin receptor (pIgR) quantitation "in vitro". RESULTS: The expression of secretory IgA was significantly reduced in bronchial epithelium (p = 0.011) and plasma cell numbers was significantly reduced in the bronchial lamina propria (p = 0.017) of rapid decliners compared to no decliners. Bronchial inflammatory cell infiltration, CD4, CD8, CD68, CD20, NK, neutrophils, eosinophils, mast cells, pIgR, was not changed in epithelium and lamina propria of rapid decliners compared to other groups. Plasma cells/mm2 correlated positively with scored total IgA in lamina propria of all patients. "In vitro" stimulation of 16HBE cells with LPS (10 µg/ml) and IL-8 (10 ng/ml) induced a significant increase while H2O2 (100 µM) significantly decreased pIgR epithelial expression. CONCLUSION: These data show an impaired humoral immune response in rapid decliners with COPD, marked by reduced epithelial secretory IgA and plasma cell numbers in the bronchial lamina propria. These findings may help in the prognostic stratification and treatment of COPD.

Role of oxidative stress in the pathogenesis of COPD.

Chronic inhalation of cigarette smoke is a prominent cause of chronic obstructive pulmonary disease (COPD) and provides an important source of exogenous oxidants. In addition, several inflammatory and structural cells are a source of endogenous oxidants in the lower airways of COPD patients, even in former smokers. This suggests that oxidants play a key role in the pathogenesis of COPD. This oxidative stress is counterbalanced by the protective effects of the various endogenous antioxidant defenses of the lower airways. A large amount of data from animal models and patients with COPD have shown that both the stable phase of the disease, and during exacerbations, have increased oxidative stress in the lower airways compared with age-matched smokers with normal lung function. Thus, counteracting the increased oxidative stress may produce clinical benefits in COPD patients. Smoking cessation is currently the most effective treatment of COPD patients and reduces oxidative stress in the lower airways. In addition, many drugs used to treat COPD have some antioxidant effects, however, it is still unclear if their clinical efficacy is related to pharmacological modulation of the oxidant/antioxidant balance. Several new antioxidant compounds are in development for the treatment of COPD.

Evolving concepts in COPD and lung cancer: a narrative review.

Lung cancer (LC) and chronic obstructive pulmonary disease (COPD) represent leading causes of morbidity and mortality worldwide. Common risk factors lead to an increased inflammatory response, enhances oxidative stress, and changes in lung microenvironment contributing to fine-tuned interaction between these respiratory disorders. Despite evidence that COPD represents a main risk factor for LC, assessment of LC risk features among COPD patients is not routinely considered in the clinical practice. In LC patients concurrent COPD may impact on clinical scenario influencing the response to treatment. Better understanding LC and COPD coexistence may impact on clinical scenario influencing therapeutic approach. In this review, we describe the basis of this network and how the complex interplay between these respiratory disorders affects the clinical decision-making process.

Treatable traits in COPD patients.

There is no justification for a therapeutic nihilism in clinical practice because current management (pharmacological and non-pharmacological) of the patients with chronic obstructive pulmonary disease according to treatable traits is effective in decreasing their respiratory symptoms, increasing their exercise tolerance and capacity, improving their quality of life, preventing (and treating) many of their exacerbations and decreasing their mortality.

Corticosteroid resistance in asthma: Cellular and molecular mechanisms.

Inhaled glucocorticoids (GCs) are drugs widely used as treatment for asthma patients. They prevent the recruitment and activation of lung immune and inflammatory cells and, moreover, have profound effects on airway structural cells to reverse the effects of disease on airway inflammation. GCs bind to a specific receptor, the glucocorticoid receptor (GR), which is a member of the nuclear receptor superfamily and modulates pro- and anti-inflammatory gene transcription through a number of distinct and complementary mechanisms. Targets genes include many pro-inflammatory mediators such as chemokines, cytokines, growth factors and their receptors. Inhaled GCs are very effective for most asthma patients with little, if any, systemic side effects depending upon the dose. However, some patients show poor asthma control even after the administration of high doses of topical or even systemic GCs. Several mechanisms relating to inflammation have been considered to be responsible for the onset of the relative GC resistance observed in these patients. In these patients, the side-effect profile of GCs prevent continued use of high doses and new drugs are needed. Targeting the defective pathways associated with GC function in these patients may also reactivate GC responsiveness.

[Risk of diabetes mellitus during regular long-term inhaled glucocorticoid treatment in COPD patients: narrative review of the literature.] / Rischio di diabete mellito durante il trattamento regolare a lungo termine con glucocorticoidi per via inalatoria nei pazienti con BPCO: revisione narrativa della letteratura.

Glucocorticoids are anti-inflammatory drugs used in combination with inhaled bronchodilators, such as ß2-agonists and antimuscarinics, for the treatment of stable chronic obstructive pulmonary disease (COPD), to improve respiratory symptoms, such as exertional dyspnoea, and to decrease the risk of future COPD exacerbations. However, it remains controversial whether their regular long-term use increases the risk of developing diabetes mellitus. The objective of this narrative review is therefore to analyse all the randomized controlled trials performed in patients with stable COPD to identify the risk of new onset diabetes mellitus during a long-term (at least 52 weeks) regular treatment with inhaled glucocorticoids alone compared to placebo. From a literature search on PubMed, 19 studies fulfilling these criteria have been identified. The inhaled glucocorticoids administered were: fluticasone propionate (7 studies), budesonide (6 studies), mometasone furoate (3 studies), beclomethasone dipropionate (1 study), triamcinolone acetonide (1 study), and fluticasone furoate (1 study) respectively. Only 3 out of the 19 trials identified in our narrative review reported data on diabetes mellitus, and in these the incidence of diabetes mellitus was not significantly different in both treatment arms (inhaled glucocorticoids and placebo), regardless of the type of glucocorticoid used.

Adiponectin is Associated with Neutrophils to Lymphocyte Ratio in Patients with Chronic Obstructive Pulmonary Disease.

Disproportionate systemic inflammation in chronic obstructive pulmonary disease (COPD) is associated with declining lung functions and comorbidities. Neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR) have emerged as valuable markers of the systemic inflammation in COPD. Adiponectin (Acpr30) circulates in serum as complexes of different molecular weight (HMW, MMW, LMW) with multifaceted metabolic and anti-inflammatory properties implicated in airway pathophysiology. We aimed to investigate the association between Acpr30 and its oligomers and the NLR and PLR in COPD patients. Seventy stable COPD patients were enrolled. Acrp30 serum levels and the HMW oligomers as well as hematological parameters and their ratio were evaluated. Both NLR and PLR are associated with lower BMI. Interestingly, total Acpr30 is negatively associated with NLR but not with PLR; after adjusting for age, BMI and FEV1, Acpr30 was independently associated with NLR. Conversely, HMW Acpr30 and HMW/Acpr30 ratio were positively correlated to NLR. The association of Acpr30, HMW Acpr30 and HMW/totalAcpr30 ratio with NLR but not with PLR in COPD patients indicates that Acrp30 oligomerization could represent a biological mechanism interfering with systemic inflammation in COPD. Further studies in larger cohorts of patients are required to confirm these results.

Role of Atypical Chemokines and Chemokine Receptors Pathways in the Pathogenesis of COPD.

Chronic obstructive pulmonary disease (COPD) represents a heightened inflammatory response in the lung generally resulting from tobacco smoking-induced recruitment and activation of inflammatory cells and/or activation of lower airway structural cells. Several mediators can modulate activation and recruitment of these cells, particularly those belonging to the chemokines (conventional and atypical) family. There is emerging evidence for complex roles of atypical chemokines and their receptors (such as high mobility group box 1 (HMGB1), antimicrobial peptides, receptor for advanced glycosylation end products (RAGE) or toll-like receptors (TLRs)) in the pathogenesis of COPD, both in the stable disease and during exacerbations. Modulators of these pathways represent potential novel therapies for COPD and many are now in preclinical development. Inhibition of only a single atypical chemokine or receptor may not block inflammatory processes because there is redundancy in this network. However, there are many animal studies that encourage studies for modulating the atypical chemokine network in COPD. Thus, few pharmaceutical companies maintain a significant interest in developing agents that target these molecules as potential antiinflammatory drugs. Antibody-based (biological) and small molecule drug (SMD)-based therapies targeting atypical chemokines and/or their receptors are mostly at the preclinical stage and their progression to clinical trials is eagerly awaited. These agents will most likely enhance our knowledge about the role of atypical chemokines in COPD pathophysiology and thereby improve COPD management.

Evaluation of Innate Immune Mediators Related to Respiratory Viruses in the Lung of Stable COPD Patients.

Background: Little is known about the innate immune response to viral infections in stable Chronic Obstructive Pulmonary Disease (COPD). Objectives: To evaluate the innate immune mediators related to respiratory viruses in the bronchial biopsies and lung parenchyma of stable COPD patients. Methods: We evaluated the immunohistochemical (IHC) expression of Toll-like receptors 3-7-8-9 (TLR-3-7-8-9), TIR domain-containing adaptor inducing IFNß (TRIF), Interferon regulatory factor 3 (IRF3), Phospho interferon regulatory factor 3  ( pIRF3), Interferon regulatory factor 7 (IRF7), Phospho interferon regulatory factor 7 (pIRF7), retinoic acid-inducible gene I (RIG1), melanoma differentiation-associated protein 5 (MDA5), Probable ATP-dependent RNA helicase DHX58 ( LGP2), Mitochondrial antiviral-signaling protein (MAVS), Stimulator of interferon genes (STING), DNA-dependent activator of IFN regulatory factors (DAI), forkhead box protein A3(FOXA3), Interferon alfa (IFNα), and Interferon beta (IFNß) in the bronchial mucosa of patients with mild/moderate (n = 16), severe/very severe (n = 18) stable COPD, control smokers (CS) (n = 12), and control non-smokers (CNS) (n = 12). We performed similar IHC analyses in peripheral lung from COPD (n = 12) and CS (n = 12). IFNα and IFNß were assessed in bronchoalveolar lavage (BAL) supernatant from CNS (n = 8), CS (n = 9) and mild/moderate COPD (n = 12). Viral load, including adenovirus-B, -C, Bocavirus, Respiratory syncytial Virus (RSV),Human Rhinovirus (HRV), Coronavirus, Influenza virus A (FLU-A), Influenza virus B (FLU-B), and Parainfluenzae-1 were measured in bronchial rings and lung parenchyma of COPD patients and the related control group (CS). Results: Among the viral-related innate immune mediators, RIG1, LGP2, MAVS, STING, and DAI resulted well expressed in the bronchial and lung tissues of COPD patients, although not in a significantly different mode from control groups. Compared to CS, COPD patients showed no significant differences of viral load in bronchial rings and lung parenchyma. Conclusions: Some virus-related molecules are well-expressed in the lung tissue and bronchi of stable COPD patients independently of the disease severity, suggesting a "primed" tissue environment capable of sensing the potential viral infections occurring in these patients.

Role of the mucins in pathogenesis of COPD: implications for therapy.

Introduction: Evidence accumulated in the last decade has started to reveal the enormous complexity in the expression, interactions and functions of the large number of different mucins present in the different compartments of the human lower airways. This occurs both in normal subjects and in COPD patients in different clinical phases and stages of severity.Areas covered: We review the known physiological mechanisms that regulate mucin production in human lower airways of normal subjects, the changes in mucin synthesis/secretion in COPD patients and the clinical efficacy of drugs that modulate mucin synthesis/secretion.Expert opinion: It is evident that the old simplistic concept that mucus hypersecretion in COPD patients is associated with negative clinical outcomes is not valid and that the therapeutic potential of 'mucolytic drugs' is under-appreciated due to the complexity of the associated molecular network(s). Likewise, our current knowledge of the effects of the drugs already available on the market that target mucin synthesis/secretion/structure in the lower airways is extremely limited and often indirect and more well-controlled clinical trials are needed in this area.

Transcription inhibitors and inflammatory cell activity.

Inflammation is a central feature of asthma and chronic obstructive pulmonary disease (COPD). Despite recent advances in the knowledge of the pathogenesis of asthma and COPD, much more research on the molecular mechanisms of asthma and COPD are needed to aid the logical development of new therapies for these common and important diseases, particularly in COPD where no new effective treatments currently exist. In the future the role of the activation/repression of different transcription factors and the genetic regulation of their expression in asthma and COPD may be an increasingly important aspect of research, as this may be one of the critical mechanisms regulating the expression of different clinical phenotypes and their responsiveness to therapy, particularly to anti-inflammatory drugs.

Molecular links between COPD and lung cancer: new targets for drug discovery?

INTRODUCTION: COPD and lung cancer are leading causes of morbidity and mortality worldwide, and they share a common environmental risk factor in cigarette smoke exposure and a genetic predisposition represented by their incidence in only a fraction of smokers. This reflects the ability of cigarette smoke to induce an inflammatory response in the airways of susceptible smokers. Moreover, COPD could be a driving factor in lung cancer, by increasing oxidative stress and the resulting DNA damage and repression of the DNA repair mechanisms, chronic exposure to pro-inflammatory cytokines, repression of innate immunity and increased cellular proliferation. Areas covered: We have focused our review on the potential pathogenic molecular links between tobacco smoking-related COPD and lung cancer and the potential molecular targets for new drug development by understanding the common signaling pathways involved in COPD and lung cancer. Expert commentary: Research in this field is mostly limited to animal models or small clinical trials. Large clinical trials are needed but mostly combined models of COPD and lung cancer are necessary to investigate the processes caused by chronic inflammation, including genetic and epigenetic alteration, and the expression of inflammatory mediators that link COPD and lung cancer, to identify new molecular therapeutic targets.