Lung cancer and inflammation: interaction of chemokines and hnRNPs

A prediction of the CRNDE role by modulating NF-κB pathway in inflammatory bowel disease (IBD)

Long non-coding RNAs (lncRNAs) regulate multiple pathways and cellular mechanisms. Recent research has emphasized their involvement in the pathogenesis of complex diseases, such as Inflammatory Bowel Disease (IBD) which is characterized by chronic inflammation of the intestines. The two most common types of IBD are ulcerative colitis and Crohn's disease. CRNDE lncRNA was initially detected in colorectal cancer (CRC) and found to be involved in the tumorigenesis pathways. Further studies revealed the role of CRNDE in activating inflammation and promoting the release of inflammatory cytokines. This study utilizes the RNA-seq data analysis and bioinformatics tools to clarify the role of CRNDE in the IBD pathogenesis and confirms its expression in inflamed HT-29 and Caco-2 cell lines and also colonic and blood samples of UC patients and controls ex vivo. Based on our results, CRNDE was significantly upregulated in IBD samples compared to controls in RNA-seq data analysis and Real-time PCR of inflamed HT-29 cell line and colonic biopsies from UC patients. Additionally, predicted that its expression is positively correlated with the pro-inflammatory cytokines production. CRNDE interactions was investigated with several inflammation-related miRNAs and regulatory proteins computationally. Thus, CRNDE upregulation in the colon of IBD patients could be involved in IBD pathogenesis by promoting inflammatory pathways and targeting anti-inflammatory miRNAs.

Dysregulated RNA processing and metabolism: a new hallmark of ageing and provocation for cellular senescence

The human genome is capable of producing hundreds of thousands of different proteins and non-coding RNAs from <20 000 genes, in a co-ordinated and regulated fashion. This is achieved by a collection of phenomena known as mRNA processing and metabolism, and encompasses events in the life cycle of an RNA from synthesis to degradation. These factors are critical determinants of cellular adaptability and plasticity, which allows the cell to adjust its transcriptomic output in response to its internal and external environment. Evidence is building that dysfunctional RNA processing and metabolism may be a key contributor to the development of cellular senescence. Senescent cells by definition have exited cell cycle, but have gained functional features such as the secretion of the senescence-associated secretory phenotype (SASP), a known driver of chronic disease and perhaps even ageing itself. In this review, I will outline the impact of dysregulated mRNA processing and metabolism on senescence and ageing at the level of genes, cells and systems, and describe the mechanisms by which progressive deterioration in these processes may impact senescence and organismal ageing. Finally, I will present the evidence implicating this important process as a new hallmark of ageing, which could be harnessed in the future to develop new senotherapeutic interventions for chronic disease.

Emerging roles of hnRNP A2B1 in cancer and inflammation

Heterogeneous nuclear ribonucleoproteins (hnRNPs) are a group of RNA-binding proteins with important roles in multiple aspects of nucleic acid metabolism, including the packaging of nascent transcripts, alternative splicing, transactivation of gene expression, and regulation of protein translation. As a core component of the hnRNP complex in mammalian cells, heterogeneous nuclear ribonucleoprotein A2B1 (hnRNP A2B1) participates in and coordinates various molecular events. Given its regulatory role in inflammation and cancer progression, hnRNP A2B1 has become a novel player in immune response, inflammation, and cancer development. Concomitant with these new roles, a surprising number of mechanisms deemed to regulate hnRNP A2B1 functions have been identified, including post-translational modifications, changes in subcellular localization, direct interactions with multiple DNAs, RNAs, and proteins or the formation of complexes with them, which have gradually made hnRNP A2B1 a molecular target for multiple drugs. In light of the rising interest in the intersection between cancer and inflammation, this review will focus on recent knowledge of the biological roles of hnRNP A2B1 in cancer, immune response, and inflammation.

Requirement of splicing factor hnRNP A2B1 for tumorigenesis of melanoma stem cells

Background

Cancer stem cells play essential roles in tumorigenesis, thus forming an important target for tumor therapy. The hnRNP family proteins are important splicing factors that have been found to be associated with tumor progression. However, the influence of hnRNPs on cancer stem cells has not been extensively explored.

Methods

Quantitative real-time PCR and Western blot were used to examine gene expressions. RNA immunoprecipitation assays were conducted to identify the RNAs interacted with hnRNP A2B1. The in vivo assays were performed in nude mice.

Results

In this study, the results showed that out of 19 evaluated hnRNPs, hnRNP A2B1 was significantly upregulated in melanoma stem cells compared with non-stem cells, suggesting an important role of hnRNP A2B1 in cancer stem cells. Silencing of hnRNP A2B1 triggered cell cycle arrest in G2 phase, leading to apoptosis of melanoma stem cells. The results also revealed that hnRNP A2B1 could bind to the precursor mRNAs of pro-apoptosis genes (DAPK1, SYT7, and RNF128) and anti-apoptosis genes (EIF3H, TPPP3, and DOCK2) to regulate the splicing of these 6 genes, thus promoting the expressions of anti-apoptosis genes and suppressing the expressions of pro-apoptosis genes. The in vivo data indicated that hnRNP A2B1 was required for tumorigenesis by affecting the splicing of TPPP3, DOCK2, EIF3H, RNF128, DAPK1, and SYT7, thus suppressing apoptosis of melanoma stem cells.

Conclusion

Our findings showed the requirement of hnRNP A2B1 for tumorigenesis, thus presenting novel molecular insights into the role of hnRNPs in cancer stem cells.

Identification of a novel and potent small molecule inhibitor of SRPK1: mechanism of dual inhibition of SRPK1 for the inhibition of cancer progression

Protein kinases are the family of attractive enzyme targets for drug design with relevance to cancer biology. Serine arginine protein kinase 1 (SRPK1) is responsible for the phosphorylation of serine/arginine (SR)-rich proteins. Alternative Splicing Factor/Splicing Factor 2 (ASF/SF2) involved in mRNA editing. ASF/SF2 is over expressed in many cancers and plays crucial roles in the cell survival. Phosphorylation of ASF/SF2 is decisive for its functions in cancer. In search of potential anticancer therapeutic agents for attenuating phosphorylation of ASF/SF2, we have explored specific and potential inhibitors of SRPK1 from natural and drug like compounds databases using in-silico methods. Compound ZINC02154892 (C02) was found to be the most potent inhibitor for SRPK1. In-vitro molecular and cell biology studies have shown C02 as a potent and specific inhibitor of phosphorylation of ASF/SF2 and cell survival in leukemic cell line. Structural analysis of SRPK1 with compound C02 revealed a unique pattern of binding targeting ATP binding site along with inhibiting recruitment of ASF/SF2 by SRPK1. The possibilities of compound C02 to be used as a lead compound paving way for the development of potent and specific inhibitors of SRPK1 for designing of novel potential anticancer inhibitor is inferred from the current studies.

Significance of inflammatory indexes in atezolizumab monotherapy outcomes in previously treated non-small-cell lung cancer patients

Cancer immunotherapy, including atezolizumab monotherapy, is a promising alternative strategy for patients with advanced non-small-cell lung cancer (NSCLC). Several inflammatory indices have been reported as potential biomarkers regarding the effectiveness of various treatments. This study aimed to analyze the efficacy of atezolizumab monotherapy using baseline inflammatory markers in NSCLC patients. We retrospectively enrolled 81 NSCLC patients who received atezolizumab monotherapy at six different medical institutions in Japan. The Cox proportional hazards model was used to assess the impact of the clinical variables, including inflammatory indexes, on clinical outcomes. Median progression-free survival (PFS) and overall survival (OS) were 60 days and 252 days, respectively. The objective response rate was 7.4%, and the disease control rate was 54.3%. Patients with high neutrophil to lymphocyte ratio (NLR), low lymphocyte to monocyte ratio (LMR), and/or high platelet to lymphocyte ratio (PLR), at baseline, demonstrated substantially shorter PFS and OS compared to those with a low NLR, high LMR, and/or low PLR. The multivariate analysis demonstrated that a high baseline NLR was substantially associated with short PFS and short OS. Our retrospective observations suggest that inflammatory indices may be a potential negative prognostic factor of atezolizumab monotherapy outcomes in NSCLC patients.

Establishment and validation of a drug-target microarray for SARS-CoV-2

COVID-19 has become one of the worst epidemic in the world, currently already more than four million people have been infected, which probably co-exist with human beings, and has a significant impact on the global economy and political order. In the process of fighting against the epidemic in China, the clinical value of a variety of herbal medicines has been recognized and written into the clinical application guide. However, their effective molecular mechanism and potential targets are still not clear. Pathology and pharmacology research will gradually attract attention in the post-epidemic outbreak term. Here, we constructed a COVID-19 protein microarray of potential therapy targets, which contains the main drug targets to the SARS-CoV-2 virus and the anti-virus, anti-inflammatory cellar targets of the host. Series of quality controls test has been carried out, which showed that it could be applied for drug target screening of bio-active natural products. The establishment of this microarray will provide a useful tool for the study of the molecular pharmacology of natural products.

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This study first proposed the idea of SARS-CoV-2 specific protein target microarray.

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The microarray was established and validated by practical test.

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Network pharmacology suggest this chip has a broad application in pharmacology.

Inflammatory Microenvironment Modulation of Alternative Splicing in Cancer: A Way to Adapt

The relationship between inflammation and cancer has been long recognized by the medical and scientific community. In the last decades, it has returned to the forefront of clinical oncology since a wealth of knowledge has been gathered about the cells, cytokines and physiological processes that are central to both inflammation and cancer. It is now robustly established that chronic inflammation can induce certain cancers but also that solid tumors, in turn, can initiate and perpetuate local inflammatory processes that foster tumor growth and dissemination. Inflammation is the hallmark of the innate immune response to tissue damage or infection, but also mediates the activation, expansion and recruitment to the tissues of cells and antibodies of the adaptive immune system. The functional integration of both components of the immune response is crucial to identify and subdue tumor development, progression and dissemination. When this tight control goes awry, altered cells can avoid the immune surveillance and even subvert the innate immunity to promote their full oncogenic transformation. In this chapter, we make a general overview of the most recent data linking the inflammatory process to cancer. We start with the overall inflammatory cues and processes that influence the relationship between tumor and the microenvironment that surrounds it and follow the ever-increasing complexity of processes that end up producing subtle changes in the splicing of certain genes to ascertain survival advantage to cancer cells.

Alternative Splicing of SMAD4 and Its Function in HaCaT Cells in Response to UVB Irradiation

Alternative splicing is one of the most common mechanisms of human gene regulation and plays a crucial role in increasing the diversity of functional proteins. Many diseases are linked to alternative splicing, especially cancer. SMAD4 is a member of the SMAD family and plays a critical role in mediating of TGF-β signal transduction and gene regulatory events. Smad4 is a tumour suppressor and acts as a shuttling protein between nucleus and cytoplasm. The splicing variants of Smad4 have been found in many cancers. The present study performed nested PCR to detect alternative splicing of Smad4 in HaCaT cells lines in response to UVB irradiation. The UVB induced a novel Smad4B isoform that led to decrease the Smad4 expression. The hnRNPA1 splicing factor is responsible for Smad4 alternative splicing in response to UVB. The UVB increased the expression of SF2 and hnRNPA1 Splicing factors. The hnRNPA1 overexpression induced Smad4B by regulating Smad4 alternative splicing. The Smad4B isoform supported the function of Smad4 full length in UVB resistance with certain limitation. The western blot analyses showed that the overexpressed Smad4 full length significantly increased N-cadherin expression while Smad4B overexpression decreased the expression the N-cadherin (P<0.05). Furthermore, overexpression of the isoform in HaCaT cells decreased cell invasion as compared to Smad4 full-length overexpression. These results will be helpful to understand the importance of Smad4 alternative splicing in skin tumorigenesis.

Posttranscriptional control of airway inflammation

Acute inflammation in the lungs is a vital protective response, efficiently and swiftly eliminating inciters of tissue injury. However, in respiratory diseases characterized by chronic inflammation, such as chronic obstructive pulmonary disease and asthma, enhanced expression of inflammatory mediators leads to tissue damage and impaired lung function. Although transcription is an essential first step in the induction of proinflammatory genes, tight regulation of inflammation requires more rapid, flexible responses. Increasing evidence shows that such responses are achieved by posttranscriptional mechanisms directly affecting mRNA stability and translation initiation. RNA-binding proteins, microRNAs, and long noncoding RNAs interact with messenger RNA and each other to impact the stability and/or translation of mRNAs implicated in lung inflammation. Recent research has shown that these biological processes play a central role in the pathogenesis of several important pulmonary conditions. This review will highlight several posttranscriptional control mechanisms that influence lung inflammation and the known associations of derangements in these mechanisms with common respiratory diseases. WIREs RNA 2018, 9:e1455. doi: 10.1002/wrna.1455 This article is categorized under: RNA in Disease and Development > RNA in Disease RNA Structure and Dynamics > Influence of RNA Structure in Biological Systems RNA Interactions with Proteins and Other Molecules > Protein-RNA Interactions: Functional Implications RNA Turnover and Surveillance > Regulation of RNA Stability.

Postoperative survival According to the Glasgow Prognostic Score in Patients with Resected Lung Adenocarcinoma

Background:

The Glasgow Prognostic Score (GPS) is calculated from measured CRP and albumin levels. We here evaluated the significance of the GPS in patients with resected pulmonary adenocarcinoma.

Materials and Methods:

The present study included 156 patients with lung adenocarcinoma who underwent lobectomy at Kanazawa Medical University between 2002 and 2012.

Classification was into three groups:

Those with normal albumin (>=3.5 g/dl) and C-reactive protein (CRP) (<=1.0 mg/dl) levels were classified as GPS 0 (n =136), those with low albumin (<3.5 g/dl) or elevated CRP (>1.0 mg/dl) levels as GPS 1 (n = 16), and those with low albumin (<3.5 g/dl) and elevated CRP (>1.0 mg/dl) levels as GPS 2 (n = 4). We retrospectively investigated relationships between the patient characteristics including the GPS, and disease-free survival and cancer-specific survival.

Results:

The pathological stages of the patients were as follows: IA (n=78, 50%), IB (n=31, 19.9%), IIA (n=20.0, 12.8%), IIB (n=9.0, 5.7%), and IIIA (n=18.0, 11.5%). Lobectomy was performed in all cases. The average GPS was 0.15 (0-2) and showed significant relationships with stage and tumor size. The 2-year survival rates in patients with GPS0, 1 and 2 were 81.4%, 38.4%, and 25.0%, respectively. Clear correlations were noted with both cancer-specific survival and disease-free survival. Furthermore, multivariate analysis revealed that GPS was a significant prognostic factor.

Conclusions:

The GPS could be a prognostic factor for patients with resected pulmonary adenocarcinoma.

Proteomics in thyroid cytopathology: Relevance of MALDI-imaging in distinguishing malignant from benign lesions

Several proteomic strategies are used extensively for the purpose of biomarker discovery and in order to obtain insights into the molecular aspects of cancers, using either body fluids or tissue as samples. Among them, MALDI-imaging can be applied to cytological thyroid specimens to investigate the molecular signatures of different pathological conditions and highlight differences in the proteome that are of relevance for diagnostic and pathogenetic research. In this study, 26 ex-vivo fine needle aspirations from benign thyroid nodules (n = 13) and papillary thyroid carcinomas (n = 13) were analyzed by MALDI-imaging. Based on the specific protein signatures capable of distinguishing the aforementioned patients, MALDI-imaging was able to correctly assign, in blind, the specimens from ten additional FNABs to a malignant or benign class, as later confirmed by the morphological classification. Moreover, some proteins presented a progressive overexpression in malignant phenotypes when compared with Hashimoto's thyroiditis and hyperplastic/follicular adenoma. This data not only suggests that a MALDI-imaging based approach can be a valuable tool in the diagnosis of thyroid lesions but also in the detection of proteins that have a possible role in the promotion of tumorigenic activity.

Glasgow prognostic score predicts prognosis of non-small cell lung cancer: a meta-analysis

OBJECTIVE

Glasgow prognostic score (GPS), an inflammation-based scoring system, has been evaluated in various cancers. However, its clinical significance remains unclear in non-small cell lung cancer (NSCLC). Therefore, it is necessary to conduct a meta-analysis to explore the prognostic value of GPS in NSCLC patients.

METHODS

A quantitative meta-analysis was performed through a systematic search in PubMed, Web of Science, and the Cochrane Library. The pooled hazard ratios (HRs) of overall survival (OS) were calculated and compared.

RESULTS

A total of 12 studies comprising 2669 patients were included in this meta-analysis. Compared with GPS 0 group, patients in GPS 1-2 group exhibited a reduced OS with a pooled HR of 1.89 (95 % CI 1.57-2.27, p < 0.001; I (2) = 54 %). Six studies had sufficient data to calculate HRs of OS for GPS 1 and GPS 2 groups. Analysis revealed that GPS 2 group had a statistically significant reduced OS compared with GPS 1 group with a pooled HR of 1.87 (95 % CI 1.18-2.97, p = 0.008; I (2) = 72 %). Study type (retrospective vs. prospective) and disease stage could partially explain the heterogeneity of each study by subgroup analysis.

CONCLUSION

Pretreatment GPS could serve as a simple and reliable prognosis predictor for NSCLC. More well-designed studies that consider GPS as a stratification factor are warranted.

hnRNPA2/B1 activates cyclooxygenase-2 and promotes tumor growth in human lung cancers

Cyclooxygenase-2 (COX-2) is highly expressed in tumor cells and has been regarded as a hallmarker for cancers, but the excise regulatory mechanism of COX-2 in tumorigenesis remains largely unknown. Here, we pulled down and identified a novel COX-2 regulator, heterogeneous nuclear ribonucleoprotein A2/B1 (hnRNPA2/B1), which could specifically bind to COX-2 core promoter and regulate tumor growth in non-small-cell lung cancers (NSCLCs). Knockdown of hnRNPA2/B1 by shRNA or siRNA downregulated COX-2 expression and prostaglandin E2 (PGE2) production, and suppressed tumor cell growth in NSCLC cells in vitro and in vivo. Conversely, overexpression of hnRNPA2/B1 up-regulated the levels of COX-2 and PGE2 and promoted tumor cell growth. We also showed that hnRNPA2/B1 expression was positively correlated with COX-2 expression in NSCLC cell lines and tumor tissues, and the up-regulated expression of hnRNPA2/B1 and COX-2 predicted worse prognosis in NSCLC patients. Furthermore, we demonstrated that the activation of COX-2 expression by hnRNPA2/B1 was mediated through the cooperation with p300, a transcriptional co-activator, in NSCLC cells. The hnRNPA2/B1 could interact with p300 directly and be acetylated by p300. Exogenous overexpression of p300, but not its histone acetyltransferase (HAT) domain deletion mutation, augmented the acetylation of hnRNPA2/B1 and enhanced its binding on COX-2 promoter, thereby promoted COX-2 expression and lung cancer cell growth. Collectively, our results demonstrate that hnRNPA2/B1 promotes tumor cell growth by activating COX-2 signaling in NSCLC cells and imply that the hnRNPA2/B1/COX-2 pathway may be a potential therapeutic target for human lung cancers.

LncRNAs: emerging biomarkers in gastric cancer

Long noncoding RNAs (lncRNAs) recently have been recognized as having a critical role in cancer development and progression. Gastric cancer remains a major clinical challenge worldwide owing to poor prognosis and limited treatment options. Accumulating studies have demonstrated that lncRNAs may play an active role in tumorigenesis, metastasis, prognosis and drug resistance of gastric cancer. Here, we collect recent knowledge to show differential expression of lncRNA in gastric cancer and their underlying mechanism of activities in gastric cancer involved in epigenetic, transcription and post-transcriptional processing. This review focuses on the regulation and function of gastric cancer-related lncRNAs and provides an overview of current effects to exploit them to be potential biomarkers and therapeutic targets for gastric cancer.

Analysis of the intricate relationship between chronic inflammation and cancer

Deregulated inflammatory response plays a pivotal role in the initiation, development and progression of tumours. Potential molecular mechanism(s) that drive the establishment of an inflammatory-tumour microenvironment is not entirely understood owing to the complex cross-talk between pro-inflammatory and tumorigenic mediators such as cytokines, chemokines, oncogenes, enzymes, transcription factors and immune cells. These molecular mediators are critical linchpins between inflammation and cancer, and their activation and/or deactivation are influenced by both extrinsic (i.e. environmental and lifestyle) and intrinsic (i.e. hereditary) factors. At present, the research pertaining to inflammation-associated cancers is accumulating at an exponential rate. Interest stems from hope that new therapeutic strategies against molecular mediators can be identified to assist in cancer treatment and patient management. The present review outlines the various molecular and cellular inflammatory mediators responsible for tumour initiation, progression and development, and discusses the critical role of chronic inflammation in tumorigenesis.

Coordinated post-transcriptional regulation of the chemokine system: messages from CCL2

The molecular cross-talk between epithelium and immune cells in the airway mucosa is a key regulator of homeostatic immune surveillance and is crucially involved in the development of chronic lung inflammatory diseases. The patterns of gene expression that follow the sensitization process occurring in allergic asthma and chronic rhinosinusitis and those present in the neutrophilic response of other chronic inflammatory lung diseases such as chronic obstructive pulmonary disease (COPD) are tightly regulated in their specificity. Studies exploring the global transcript profiles associated with determinants of post-transcriptional gene regulation (PTR) such as RNA-binding proteins (RBP) and microRNAs identified several of these factors as being crucially involved in controlling the expression of chemokines upon airway epithelial cell stimulation with cytokines prototypic of Th1- or Th2-driven responses. These studies also uncovered the participation of these pathways to glucocorticoids' inhibitory effect on the epithelial chemokine network. Unmasking the molecular mechanisms of chemokine PTR may likely uncover novel therapeutic strategies for the blockade of proinflammatory pathways that are pathogenetic for asthma, COPD, and other lung inflammatory diseases.

Regulation of C-X-C chemokine gene expression by keratin 17 and hnRNP K in skin tumor keratinocytes

Interaction between K17 and hnRNP K regulates CXCR3 signaling in an RSK-dependent fashion to promote epithelial tumor cell growth and invasion.

High levels of the intermediate filament keratin 17 (K17) correlate with a poor prognosis for several types of epithelial tumors. However, the causal relationship and underlying mechanisms remain undefined. A recent study suggested that K17 promotes skin tumorigenesis by fostering a specific type of inflammation. We report here that K17 interacts with the RNA-binding protein hnRNP K, which has also been implicated in cancer. K17 is required for the cytoplasmic localization of hnRNP K and for its role in regulating the expression of multiple pro-inflammatory mRNAs. Among these are the CXCR3 ligands CXCL9, CXCL10, and CXCL11, which together form a signaling axis with an established role in tumorigenesis. The K17–hnRNP K partnership is regulated by the ser/thr kinase RSK and required for CXCR3-dependent tumor cell growth and invasion. These findings functionally integrate K17, hnRNP K, and gene expression along with RSK and CXCR3 signaling in a keratinocyte-autonomous axis and provide a potential basis for their implication in tumorigenesis.

A simple and rapid method for standard preparation of gas phase extract of cigarette smoke

Cigarette smoke consists of tar and gas phase: the latter is toxicologically important because it can pass through lung alveolar epithelium to enter the circulation. Here we attempt to establish a standard method for preparation of gas phase extract of cigarette smoke (CSE). CSE was prepared by continuously sucking cigarette smoke through a Cambridge filter to remove tar, followed by bubbling it into phosphate-buffered saline (PBS). An increase in dry weight of the filter was defined as tar weight. Characteristically, concentrations of CSEs were represented as virtual tar concentrations, assuming that tar on the filter was dissolved in PBS. CSEs prepared from smaller numbers of cigarettes (original tar concentrations ≤ 15 mg/ml) showed similar concentration-response curves for cytotoxicity versus virtual tar concentrations, but with CSEs from larger numbers (tar ≥ 20 mg/ml), the curves were shifted rightward. Accordingly, the cytotoxic activity was detected in PBS of the second reservoir downstream of the first one with larger numbers of cigarettes. CSEs prepared from various cigarette brands showed comparable concentration-response curves for cytotoxicity. Two types of CSEs prepared by continuous and puff smoking protocols were similar regarding concentration-response curves for cytotoxicity, pharmacology of their cytotoxicity, and concentrations of cytotoxic compounds. These data show that concentrations of CSEs expressed by virtual tar concentrations can be a reference value to normalize their cytotoxicity, irrespective of numbers of combusted cigarettes, cigarette brands and smoking protocols, if original tar concentrations are ≤15 mg/ml.

MALAT1 promotes cell proliferation in gastric cancer by recruiting SF2/ASF

The functions of long non-coding RNAs (lncRNAs) in gastric cancer (GC) remain largely unknown. MALAT1 is a kind of lncRNA that had been validated as a pivotal metastasis and prognosis mark in lung adenocarcinoma. In this study, we found that MALAT1 was aberrantly highly expressed in GC cell lines (SGC-7901, MKN-45 and SUN-16), and induced specific distribution and over-expression of SF2/ASF in nucleolus. Knock-down of MALAT1 or SF2/ASF in SGC-7901 cells respectively induced significant arrest of cell cycle in G0/G1 phase along with a remarkable suppression of cell proliferation, and the nuclear distribution and expression of SF2/ASF was significantly impaired when MALAT1 was depleted. However, over-expression of SF2/ASF exhibited no effect on rescuing the cell proliferation suppression by MALAT1 depletion. These results suggest that MALAT1 may function as a promoter of GC cell proliferation partly by regulating SF2/ASF, and our findings may provide us a likely biomarker and a potential target for GC diagnosis and therapeutic treatment.

Flavonoid components in Scutellaria baicalensis inhibit nicotine-induced proliferation, metastasis and lung cancer-associated inflammation in vitro

The objective of the present study was to investigate the therapeutic efficacy of flavonoid components in Scutellaria baicalensis on proliferation, metastasis and lung cancer-associated inflammation during nicotine induction in the A549 and H1299 lung cancer cell lines. After experimental period, augmentation of proliferation was observed, accompanied by marked decrease in apoptotic cells in nicotine-induced lung cancer cells; additionally, nicotine-exposed cells exhibited increased invasive and migratory abilities based on invasion and wound-healing assay. Flavones in Scutellaria, baicalin, baicalein and wogonin significantly counteracted the above deleterious changes. Moreover, assessment of tumor apoptotic and metastatic factors on mRNA levels by quantitative PCR and protein levels by western blotting revealed that these phytochemical treatments effectively negated nicotine-induced upregulated expression of bcl-2, bcl-2/bax ratio, caspase-3, matrix metalloproteinase (MMP)-2 and MMP-9 as well as downregulated expression of bax. Further analysis of inflammatory markers such as tumor necrosis factor (TNF)-α and interleukin (IL)-6 in cell culture supernatant and mRNA and protein expression of nuclear transcription factor-kappaB (NF-κB) and I kappa B-alpha (IκB-α) was carried out to substantiate the anti-inflammatory effect of flavones in Scutellaria in nicotine-exposed lung cancer cells. The therapeutic effects observed in the present study are attributed to the potent potential against proliferation, metastasis and inflammatory microenvironment by flavonoid components in Scutellaria in nicotine-induced lung cancer cells.

HnRNP A1/A2 and SF2/ASF regulate alternative splicing of interferon regulatory factor-3 and affect immunomodulatory functions in human non-small cell lung cancer cells

Heterogeneous nuclear ribonucleoparticule A1/A2 (hnRNP A1/A2) and splicing factor 2/alternative splicing factor (SF2/ASF) are pivotal for precursor messenger RNA (pre-mRNA) splicing. Interferon regulatory factor-3 (IRF-3) plays critical roles in host defense against viral and microbial infection. Truncated IRF-3 proteins resulting from alternative splicing have been identified and characterized as functional antagonists to full-length IRF-3. In this study, we examined the molecular mechanism for splicing regulation of IRF-3 pre-mRNA and first reported the regulatory effect of hnRNP A1/A2 and SF2/ASF on IRF-3 splicing and activation. RNA interference-mediated depletion of hnRNP A1/A2 or SF2/ASF in human non-small cell lung cancer (NSCLC) cells increased exclusion of exons 2 and 3 of IRF-3 gene and reduced expression levels of IRF-3 protein and IRF-3 downstream effector molecules interferon-beta and CXCL10/IP-10. In addition, direct binding of hnRNP A1 and SF2/ASF to specific binding motifs in IRF-3 intron 1 was confirmed by RNA electrophoretic mobility shift assay. Subsequent minigene splicing assay showed that IRF-3 minigenes with mutated hnRNPA 1/A2 or SF2/ASF binding motifs increased exclusion of exons 2 and 3. Moreover, knockdown of hnRNP A1/A2 or SF2/ASF in NSCLC cells reinforced phytohemagglutinin-induced tumor necrosis factor-alpha release by peripheral blood mononuclear cells (PBMC) but suppressed that of interleukin-10 in NSCLC/PBMC co-cultures. Taken together, our results suggest that specific knockdown for hnRNP A1/A2 or SF2/ASF increase exclusion of exons 2 and 3 of IRF-3 pre-mRNA and influence immunomodulatory functions of human NSCLC cells.

Dissecting the role of peroxisome proliferator-activated receptor-β/δ (PPARβ/δ) in colon, breast, and lung carcinogenesis

Peroxisome proliferator-activated receptor-β/δ (PPARβ/δ) is a promising drug target since its agonists increase serum high-density lipoprotein; decrease low-density lipoprotein, triglycerides, and insulin associated with metabolic syndrome; improve insulin sensitivity; and decrease high fat diet-induced obesity. PPARβ/δ agonists also promote terminal differentiation and elicit anti-inflammatory activities in many cell types. However, it remains to be determined whether PPARβ/δ agonists can be developed as therapeutics because there are reports showing either pro- or anti-carcinogenic effects of PPARβ/δ in cancer models. This review examines studies reporting the role of PPARβ/δ in colon, breast, and lung cancers. The prevailing evidence would suggest that targeting PPARβ/δ is not only safe but could have anti-carcinogenic protective effects.

Incidence, treatment options, and outcomes of lung cancer in patients with chronic obstructive pulmonary disease

PURPOSE OF REVIEW

An associative and mechanistic link between chronic obstructive pulmonary disease (COPD) and lung cancer has long been suspected. This review describes the current understanding of the incidence, mechanism of association, treatment options, and outcome for lung cancer with COPD.

RECENT FINDINGS

COPD patients have an increased risk of lung cancer that is independent of smoking. New evidence suggests that there is an inverse relationship between the severity of airflow obstruction and the risk of lung cancer. Chronic inflammation associated with COPD may play a role in the development of lung cancer, and targeting airway inflammation with inhaled corticosteroids has been suggested as a possible preventive strategy. Although surgical lobectomy remains the standard of care for early stage lung cancer, less invasive approaches such as sublobar resection, stereotactic body radiation therapy, and radiofrequency ablation are promising techniques for patients with limited pulmonary reserve.

SUMMARY

Progress is being made in identifying mechanistic links between COPD and lung cancer, which may lead to novel therapeutic strategies for both disorders. Patients with COPD are likely to benefit from less-invasive surgical and nonsurgical treatment strategies for lung cancer, but further study is needed to determine the safety and efficacy of these procedures.

Nicotine- and tar-free cigarette smoke induces cell damage through reactive oxygen species newly generated by PKC-dependent activation of NADPH oxidase

We examined cytotoxic effects of nicotine/tar-free cigarette smoke extract (CSE) on C6 glioma cells. The CSE induced plasma membrane damage (determined by lactate dehydrogenase leakage and propidium iodide uptake) and cell apoptosis {determined by MTS [3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium] reduction activity and DNA fragmentation}. The cytotoxic activity decayed with a half-life of approximately 2 h at 37°C, and it was abolished by N-acetyl-L-cysteine and reduced glutathione. The membrane damage was prevented by catalase and edaravone (a scavenger of (•)OH) but not by superoxide dismutase, indicating involvement of (•)OH. In contrast, the CSE-induced cell apoptosis was resistant to edaravone and induced by authentic H(2)O(2) or O(2)(-) generated by the xanthine/xanthine oxidase system, indicating involvement of H(2)O(2) or O(2)(-) in cell apoptosis. Diphenyleneiodonium [NADPH oxidase (NOX) inhibitor] and bisindolylmaleimide I [BIS I, protein kinase C (PKC) inhibitor] abolished membrane damage, whereas they partially inhibited apoptosis. These results demonstrate that 1) a stable component(s) in the CSE activates PKC, which stimulates NOX to generate reactive oxygen species (ROS), causing membrane damage and apoptosis; 2) different ROS are responsible for membrane damage and apoptosis; and 3) part of the apoptosis is caused by oxidants independently of PKC and NOX.

The role of inflammation in the pathogenesis of lung cancer

INTRODUCTION

It is reported that cancer may arise in chronically inflamed tissue. There is mounting evidence suggesting that the connection between inflammation and lung cancer is not coincidental but may indeed be causal. The inflammatory molecules may be responsible for augmented macrophage recruitment, delayed neutrophil clearance and an increase in reactive oxygen species. The cytokines and growth factors unusually produced in chronic pulmonary disorders have been found to have harmful properties that pave the way for epithelial-to-mesenchymal transition and tumor microenvironment. However, the role of inflammation in lung cancer is not yet fully understood.

AREAS COVERED

The role of chronic inflammation in the pathogenesis of lung cancer and some of the possible mechanisms involved, with particular focus on inflammatory mediators, genetic and epigenetic alterations, inflammatory markers, tumor microenvironment and anti-inflammatory drugs are discussed. A framework for understanding the connection between inflammation and lung cancer is provided, which may afford the opportunity to intercede in specific inflammatory damage mediating lung carcinogenesis and therapeutic resistance.

EXPERT OPINION

Advances in tumor immunology support the clinical implementation of immunotherapies for lung cancer. Along with therapeutic benefits, immunotherapy presents the challenges of drug-related toxicities. Gene modification of immunocytokine may lower the associated toxic effects.

S-nitrosylation in the regulation of gene transcription

BACKGROUND

Post-translational modification of proteins by S-nitrosylation serves as a major mode of signaling in mammalian cells and a growing body of evidence has shown that transcription factors and their activating pathways are primary targets. S-nitrosylation directly modifies a number of transcription factors, including NF-κB, HIF-1, and AP-1. In addition, S-nitrosylation can indirectly regulate gene transcription by modulating other cell signaling pathways, in particular JNK kinase and ras.

SCOPE OF REVIEW

The evolution of S-nitrosylation as a signaling mechanism in the regulation of gene transcription, physiological advantages of protein S-nitrosylation in the control of gene transcription, and discussion of the many transcriptional proteins modulated by S-nitrosylation is summarized.

MAJOR CONCLUSIONS

S-nitrosylation plays a crucial role in the control of mammalian gene transcription with numerous transcription factors regulated by this modification. Many of these proteins serve as immunomodulators, and inducible nitric oxide synthase (iNOS) is regarded as a principal mediatiator of NO-dependent S-nitrosylation. However, additional targets within the nucleus (e.g. histone deacetylases) and alternative mechanisms of S-nitrosylation (e.g. GAPDH-mediated trans-nitrosylation) are thought to play a role in NOS-dependent transcriptional regulation.

GENERAL SIGNIFICANCE

Derangement of SNO-regulated gene transcription is an important factor in a variety of pathological conditions including neoplasia and sepsis. A better understanding of protein S-nitrosylation as it relates to gene transcription and the physiological mechanisms behind this process is likely to lead to novel therapies for these disorders. This article is part of a Special Issue entitled Regulation of Cellular Processes by S-nitrosylation.

Chronic obstructive pulmonary disease and lung cancer: new molecular insights

Both chronic obstructive pulmonary disease (COPD) and lung cancer are major causes of death worldwide. In most cases this reflects cigarette smoke exposure which is able to induce an inflammatory response in the airways of smokers. Indeed, COPD is characterized by lower airway inflammation, and importantly, the presence of COPD is by far the greatest risk factor for lung cancer amongst smokers. Cigarette smoke induces the release of many inflammatory mediators and growth factors including TGF-β, EGFR, IL-1, IL-8 and G-CSF through oxidative stress pathways and this inflammation may persist for decades after smoking cessation. Mucus production is also increased by these inflammatory mediators, further linking airway inflammation to an important mechanism of lung cancer. A greater understanding of the molecular and cellular pathobiology that distinguishes smokers with lung cancer from smokers with and without COPD is needed to unravel the complex molecular interactions between COPD and lung cancer. By understanding the common signalling pathways involved in COPD and lung cancer the hope is that treatments will be developed that not only treat the underlying disease process in COPD, but also reduce the currently high risk of developing lung cancer in these patients.

Common pathogenic mechanisms and pathways in the development of COPD and lung cancer

INTRODUCTION

Lung cancer and COPD commonly coexist in smokers, and the presence of COPD increases the risk of developing lung cancer. In addition to smoking cessation and preventing smoking initiation, understanding the shared mechanisms of these smoking-related lung diseases is critical, in order to develop new methods of prevention, diagnosis and treatment of lung cancer and COPD.

AREAS COVERED

This review discusses the common mechanisms for susceptibility to lung cancer and COPD, which in addition to cigarette smoke, may involve inflammation, epithelial-mesenchymal transition, abnormal repair, oxidative stress, and cell proliferation. Furthermore, we discuss the underlying genomic and epigenomic changes (single nucleotide polymorphisms (SNPs), copy number variation, promoter hypermethylation and microRNAs) that are likely to alter biological pathways, leading to susceptibility to lung cancer and COPD (e.g., altered nicotine receptor biology).

EXPERT OPINION

Strategies to study genomics, epigenomics and gene-environment interaction will yield greater insight into the shared pathogenesis of lung cancer and COPD, leading to new diagnostic and therapeutic modalities.

Elevated copper remodels hepatic RNA processing machinery in the mouse model of Wilson's disease

Copper is essential to mammalian physiology, and its homeostasis is tightly regulated. In humans, genetic defects in copper excretion result in copper overload and Wilson's disease (WD). Previous studies on the mouse model for WD (Atp7b(-)(/-)) revealed copper accumulation in hepatic nuclei and specific changes in mRNA profile prior to the onset of pathology. To find a molecular link between nuclear copper elevation and changes in hepatic transcriptome, we utilized quantitative ionomic and proteomic approaches. X-ray fluorescence and inductively coupled plasma mass spectrometry analysis indicate that copper in the Atp7b(-/-) nucleus, while highly elevated, does not markedly alter nuclear ion content. Widespread protein oxidation is also not observed, although the glutathione reductase SelH is upregulated, likely to maintain redox balance. We further demonstrate that accumulating copper affects the abundance and/or modification of a distinct subset of nuclear proteins. These proteins populate pathways that are most significantly associated with RNA processing. An alteration in splicing pattern was observed for hnRNP A2/B1, itself the RNA shuttling factor and spliceosome component. Analysis of hnRNP A2/B1 mRNA and protein revealed an increased retention of exon 2 and a selective 2-fold upregulation of a corresponding protein splice variant. Mass spectrometry measurements suggest that the nucleocytoplasmic distribution of RNA binding proteins, including hnRNP A2/B1, is altered in the Atp7b(-/-) liver. We conclude that remodeling of the RNA processing machinery is an important component of cell response to elevated copper that may guide pathology development in the early stages of WD.