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.

Aim2 suppresses cigarette smoke-induced neutrophil recruitment, neutrophil caspase-1 activation and anti-Ly6G-mediated neutrophil depletion.

Increased inflammasome responses are strongly implicated in inflammatory diseases; however, their specific roles are incompletely understood. Therefore, we sought to examine the roles of nucleotide-binding oligomerization domain-like receptor (NLR) family, pyrin domain-containing 3 (NLRP3) and absent in melanoma-2 (AIM2) inflammasomes in cigarette smoke-induced inflammation in a model of experimental chronic obstructive pulmonary disease (COPD). We targeted NLRP3 with the inhibitor MCC950 given prophylactically or therapeutically and examined Aim2-/- mice in cigarette smoke-induced experimental COPD. MCC950 treatment had minimal effects on disease development and/or progression. Aim2-/- mice had increased airway neutrophils with decreased caspase-1 levels, independent of changes in lung neutrophil chemokines. Suppressing neutrophils with anti-Ly6G in experimental COPD in wild-type mice reduced neutrophils in bone marrow, blood and lung. By contrast, anti-Ly6G treatment in Aim2-/- mice with experimental COPD had no effect on neutrophils in bone marrow, partially reduced neutrophils in the blood and had no effect on neutrophils or neutrophil caspase-1 levels in the lungs. These findings identify that following cigarette smoke exposure, Aim2 is important for anti-Ly6G-mediated depletion of neutrophils, suppression of neutrophil recruitment and mediates activation of caspase-1 in neutrophils.

Impact of Deleterious Mutations on Structure, Function and Stability of Serum/Glucocorticoid Regulated Kinase 1: A Gene to Diseases Correlation.

Serum and glucocorticoid-regulated kinase 1 (SGK1) is a Ser/Thr protein kinase involved in regulating cell survival, growth, proliferation, and migration. Its elevated expression and dysfunction are reported in breast, prostate, hepatocellular, lung adenoma, and renal carcinomas. We have analyzed the SGK1 mutations to explore their impact at the sequence and structure level by utilizing state-of-the-art computational approaches. Several pathogenic and destabilizing mutations were identified based on their impact on SGK1 and analyzed in detail. Three amino acid substitutions, K127M, T256A, and Y298A, in the kinase domain of SGK1 were identified and incorporated structurally into original coordinates of SGK1 to explore their time evolution impact using all-atom molecular dynamic (MD) simulations for 200 ns. MD results indicate substantial conformational alterations in SGK1, thus its functional loss, particularly upon T256A mutation. This study provides meaningful insights into SGK1 dysfunction upon mutation, leading to disease progression, including cancer, and neurodegeneration.

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.

MCV Truncated Large T antigen interacts with BRD4 in tumors.

Among Polyomaviridae family of viruses, Merkel Cell Polyomavirus (MCV) is the only human polyomavirus with convincing data supporting its classification as a direct causative agent of a human skin malignancy, Merkel Cell Carcinoma. Oncogenic transformation by MCV requires the integration of the viral genome into the human genome, truncation of the large T antigen (LT) to render the viral genome replication deficient and expression of small T antigen oncoprotein. The chromatin binding protein BRD4, was recently shown to transcriptionally regulate the expression of virus oncoproteins, thereby enhancing the tumorigenesis of virus-associated cancers, such as HPV associated cervical cancer. Previous work by Wang et al. revealed that BRD4 interacts with MCV full length LT during viral replication. In this study, we demonstrated that MCV truncated tumor LT antigen also interacts with BRD4 protein. We showed that the MCV tumor LT antigen and BRD4 protein complex co-localizes within the nucleus. Furthermore, we tested whether BRD4 protein transcriptionally regulates MCV Non Coding Control Region (NCCR), where we found that though full length LT and sT together, along with the BRD4 protein showed enhanced transcriptional activity whereas tumor truncated LT did not. These findings on the interactions of the MCV tumor truncated LT antigen with the BRD4 protein add to existing knowledge about interactions with LT and its role in tumorigenesis, and assist in efforts to more precisely define new therapy targets for this disease.

Animal models of COPD: What do they tell us?

COPD is a major cause of global mortality and morbidity but current treatments are poorly effective. This is because the underlying mechanisms that drive the development and progression of COPD are incompletely understood. Animal models of disease provide a valuable, ethically and economically viable experimental platform to examine these mechanisms and identify biomarkers that may be therapeutic targets that would facilitate the development of improved standard of care. Here, we review the different established animal models of COPD and the various aspects of disease pathophysiology that have been successfully recapitulated in these models including chronic lung inflammation, airway remodelling, emphysema and impaired lung function. Furthermore, some of the mechanistic features, and thus biomarkers and therapeutic targets of COPD identified in animal models are outlined. Some of the existing therapies that suppress some disease symptoms that were identified in animal models and are progressing towards therapeutic development have been outlined. Further studies of representative animal models of human COPD have the strong potential to identify new and effective therapeutic approaches for COPD.