VEGF and IL-18 in induced sputum of lung cancer patients

The trigger for pancreatic disease: NLRP3 inflammasome

NLRP3 inflammasome is a multiprotein complex expressed in a variety of cells to stimulate the production of inflammatory factors. Activation of NLRP3 inflammasome depends on a complex regulatory mechanism, and its pro-inflammatory function plays an important role in pancreatic diseases. In this literature review, we summarize the activation mechanism of NLRP3 and analyze its role in each of the four typical pancreatic diseases. Through this article, we provide a relatively comprehensive summary to the researchers in this field, and provide some targeted therapy routes.

Prognostic association between NLRP3 inflammasome expression level and operable pancreatic adenocarcinoma

BACKGROUND

The NLRP3 inflammasome is significantly associated with tumor development and metastasis in various malignancies. However, the significance of the NLRP3 inflammasome in pancreatic adenocarcinoma has not been fully determined. Therefore, we try to evaluate the expression of the NLRP3 inflammasome in pancreatic adenocarcinoma and analyzed its prognostic significance.

METHODS

This cohort study enrolled 98 patients with primary pancreatic adenocarcinoma who received curative surgery. The NLRP3 inflammasome expression levels in cancer tissue were determined by immunohistochemistry, and compared with that of adjacent normal tissues. The association between NLRP3 inflammasome expression levels and baseline clinicopathological characteristics were also analyzed. Moreover, the correlation between NLRP3 inflammasome expression levels and survival was analyzed by log-rank test, and the survival curve was made by the Kaplan-Meier survival analysis.

RESULTS

Expression of each NLRP3 inflammasome component in cancer tissue was higher than that in the adjacent normal tissues (all P < 0.05), including NLRP3, IL-1β, ASC, and Caspase-1. All four components of the NLRP3 inflammasome were closely associated with clinical stage and lymph node status (all P < 0.05). The Kaplan-Meier log rank test showed that the high expression level of the NLRP3 inflammasome was significantly related to poor overall survival in pancreatic adenocarcinoma patients.

CONCLUSIONS

NLRP3 inflammasome expression was upregulated in cancer tissue and closely associated with the prognosis of operable pancreatic adenocarcinoma.

Studies in lung cancer cytokine proteomics: a review

INTRODUCTION

Proteins are molecules that have role in the progression of the diseases. Proteomics is a tool that can play an effective role in identifying diagnostic and therapeutic biomarkers for lung cancer. Cytokines are proteins that play a decisive role in activating body's immune system in lung cancer. They can increase the growth of the tumor (oncogenic cytokines) or limit tumor growth (anti-tumor cytokines) by regulating related signaling pathways such as proliferation, growth, metastasis, and apoptosis.

AREAS COVERED

In the present study, a total of 223 papers including 196 research papers and 27 review papers, extracted from PubMed and Scopus and published from 1997 to present, are reviewed. The most important involved-cytokines in lung cancer including TNF-α, IFN- γ, TGF-β, VEGF and interleukins such as IL-6, IL-17, IL-8, IL-10, IL-22, IL-1β and IL-18 are introduced. Also, the pathological and biological role of such cytokines in cancer signaling pathways is explained.

EXPERT OPINION

In lung cancer, the cytokine expression changes under the physiological conditions of the immune system, and inflammatory cytokines are associated with the progression of lung cancer. Therefore, the cytokine expression profile can be used in the diagnosis, prognosis, prediction of therapeutic responses, and survival of patients with lung cancer.

Evaluation of Detection Methods and Values of Circulating Vascular Endothelial Growth Factor in Lung Cancer

Lung cancer is the deadliest cancer in the world. Angiogenesis plays a crucial role of the incidence, progression, and metastasis in lung cancer. Angiogenesis inhibitors are used to treat non-small cell lung cancer (NSCLC) patients, and the molecular biomarkers are also being assessed to predict treatment response/therapeutic response and patients' prognosis. Vascular endothelial growth factor (VEGF) is a signal protein produced by cells that stimulates angiogenesis. Due to its predictive values of prognosis on NSCLC, a large number of methods have been developed and evaluated to detect VEGF levels in a variety of studies. In this article, we review the detection methods designed to measure the VEGF levels in different body fluids and prognosticate the value of VEGF in treatment, diagnosis and survival in lung cancer.

Hypoxia induced mitogenic factor (HIMF) triggers angiogenesis by increasing interleukin-18 production in myoblasts

Inflammatory myopathy is a rare autoimmune muscle disorder. Treatment typically focuses on skeletal muscle weakness or inflammation within muscle, as well as complications of respiratory failure secondary to respiratory muscle weakness. Impaired respiratory muscle function contributes to increased dyspnea and reduced exercise capacity in pulmonary hypertension (PH), a debilitating condition that has few treatment options. The initiation and progression of PH is associated with inflammation and inflammatory cell recruitment and it is established that hypoxia-induced mitogenic factor (HIMF, also known as resistin-like molecule α), activates macrophages in PH. However, the relationship between HIMF and inflammatory myoblasts remains unclear. This study investigated the signaling pathway involved in interleukin-18 (IL-18) expression and its relationship with HIMF in cultured myoblasts. We found that HIMF increased IL-18 production in myoblasts and that secreted IL-18 promoted tube formation of the endothelial progenitor cells. We used the mouse xenograft model and the chick chorioallantoic membrane assay to further explore the role of HIMF in inflammatory myoblasts and angiogenesis in vivo. Thus, our study focused on the mechanism by which HIMF mediates IL-18 expression in myoblasts through angiogenesis in vitro and in vivo. Our findings provide an insight into HIMF functioning in inflammatory myoblasts.

Proteomic-Based Approaches for the Study of Cytokines in Lung Cancer

Proteomic techniques are currently used to understand the biology of different human diseases, including studies of the cell signaling pathways implicated in cancer progression, which is important in knowing the roles of different proteins in tumor development. Due to its poor prognosis, proteomic approaches are focused on the identification of new biomarkers for the early diagnosis, prognosis, and targeted treatment of lung cancer. Cytokines are proteins involved in inflammatory processes and have been proposed as lung cancer biomarkers and therapeutic targets because it has been reported that some cytokines play important roles in tumor development, invasion, and metastasis. In this review, we aim to summarize the different proteomic techniques used to discover new lung cancer biomarkers and therapeutic targets. Several cytokines have been identified as important players in lung cancer using these techniques. We underline the most important cytokines that are useful as biomarkers and therapeutic targets. We also summarize some of the therapeutic strategies targeted for these cytokines in lung cancer.

Incorporating epistasis interaction of genetic susceptibility single nucleotide polymorphisms in a lung cancer risk prediction model

Incorporation of genetic variants such as single nucleotide polymorphisms (SNPs) into risk prediction models may account for a substantial fraction of attributable disease risk. Genetic data, from 2385 subjects recruited into the Liverpool Lung Project (LLP) between 2000 and 2008, consisting of 20 SNPs independently validated in a candidate-gene discovery study was used. Multifactor dimensionality reduction (MDR) and random forest (RF) were used to explore evidence of epistasis among 20 replicated SNPs. Multivariable logistic regression was used to identify similar risk predictors for lung cancer in the LLP risk model for the epidemiological model and extended model with SNPs. Both models were internally validated using the bootstrap method and model performance was assessed using area under the curve (AUC) and net reclassification improvement (NRI). Using MDR and RF, the overall best classifier of lung cancer status were SNPs rs1799732 (DRD2), rs5744256 (IL-18), rs2306022 (ITGA11) with training accuracy of 0.6592 and a testing accuracy of 0.6572 and a cross-validation consistency of 10/10 with permutation testing P<0.0001. The apparent AUC of the epidemiological model was 0.75 (95% CI 0.73–0.77). When epistatic data were incorporated in the extended model, the AUC increased to 0.81 (95% CI 0.79–0.83) which corresponds to 8% increase in AUC (DeLong's test P=2.2e-¹⁶); 17.5% by NRI. After correction for optimism, the AUC was 0.73 for the epidemiological model and 0.79 for the extended model. Our results showed modest improvement in lung cancer risk prediction when the SNP epistasis factor was added.

The interleukin-18 gene promoter -607 A/C polymorphism contributes to non-small-cell lung cancer risk in a Chinese population

The purpose of the present study was to determine the relationship between interleukin-18 (IL-18) -607 A/C polymorphism and the risk of non-small-cell lung cancer (NSCLC) and its impact on the serum IL-18 level. The genotyping of IL-18 -607 A/C polymorphism was detected by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). The results showed that the AA/AC genotype distribution in NSCLC patients was significantly higher than that of healthy controls (P=0.02). However, no significant differences were found between the two subgroups when stratified by clinical characteristics. Furthermore, serum IL-18 levels were found to be significantly higher in the NSCLC patients than in the controls (P=0.01) as detected by enzyme-linked immunosorbent assay analysis. There was no correlation between serum IL-18 levels and different genotypes. In conclusion, these findings suggest that IL-18 -607 A/C polymorphism increases the risk of NSCLC in the Chinese population, and this polymorphism could not functionally affect the IL-18 levels.

Activation of NLRP3 inflammasome enhances the proliferation and migration of A549 lung cancer cells

Lung cancer is the leading cause of cancer death, and it is widely accepted that chronic inflammation is an important risk for the development of lung cancer. Now, it is recognized that the nucleotide-binding and oligomerization domain (NOD) like receptors (NLRs)-containing inflammasomes are involved in cancer-related inflammation. This study was designed to investigate the effects of NLR family pyrin domain containing protein 3 (NLRP3) inflammasome on the proliferation and migration of lung adenocarcinoma cell line A549. Using 5-ethynyl-2'-deoxyuridine (EdU) incorporation assay, scratch assay, and Transwell migration assay, we showed that activation of the NLRP3 inflammasome by LPS+ATP enhanced the proliferation and migration of A549 cells. Western blot analysis showed that activation of phosphorylation of Akt, ERK1/2, CREB and the expression of Snail increased, while the expression of E-cadherin decreased after the activation of NLRP3 inflammasome. Moreover, these effects were inhibited by the following treatments: i) downregulating the expression of NLRP3 by short hairpin RNA (shRNA) interference, ii) inhibiting the activation of NLRP3 inflammasome with a caspase-1 inhibitor, iii) blocking the interleukin-1β (IL-1β) and IL-18 signal transduction with IL-1 receptor antagonist (IL-1Ra) and IL-18 binding protein (IL-18BP). Collectively, these results indicate that NLRP3 inflammasome plays a vital role in regulating the proliferation and migration of A549 cells and it might be a potential target for the treatment of lung cancer.

The role of interleukin-18 in glioblastoma pathology implies therapeutic potential of two old drugs-disulfiram and ritonavir

Based on reporting in the last several years, an impressive but dismal list of cytotoxic chemotherapies that fail to prolong the median overall survival of patients with glioblastoma has prompted the development of treatment protocols designed to interfere with growth-facilitating signaling systems by using non-cytotoxic, non-oncology drugs. Recent recognition of the pro-mobility stimulus, interleukin-18, as a driver of centrifugal glioblastoma cell migration allows potential treatment adjuncts with disulfiram and ritonavir. Disulfiram and ritonavir are well-tolerated, non-cytotoxic, non-oncology chemotherapeutic drugs that are marketed for the treatment of alcoholism and human immunodeficiency virus (HIV) infection, respectively. Both drugs exhibit an interleukin-18–inhibiting function. Given the favorable tolerability profile of disulfiram and ritonavir, the unlikely drug-drug interaction with temozolomide, and the poor prognosis of glioblastoma, trials of addition of disulfiram and ritonavir to current standard initial treatment of glioblastoma would be warranted.

Retinoblastoma binding protein 2 (RBP2) promotes HIF-1α-VEGF-induced angiogenesis of non-small cell lung cancer via the Akt pathway

Background

Pathological angiogenesis plays an essential role in tumor aggressiveness and leads to unfavorable prognosis. The aim of this study is to detect the potential role of Retinoblastoma binding protein 2 (RBP2) in the tumor angiogenesis of non-small cell lung cancer (NSCLC).

Methods

Immunohistochemical staining was used to detect the expression of RBP2, hypoxia-inducible factor-1α (HIF-1α), vascular endothelial growth factor (VEGF) and CD34. Two pairs of siRNA sequences and pcDNA3-HA-RBP2 were used to down-regulate and up-regulate RBP2 expression in H1975 and SK-MES-1 cells. An endothelial cell tube formation assay, VEGF enzyme-linked immunosorbent assay, real-time PCR and western blotting were performed to detect the potential mechanisms mediated by RBP2 in tumor angiogenesis.

Results

Of the 102 stage I NSCLC specimens analyzed, high RBP2 protein expression is closely associated with tumor size (P = 0.030), high HIF-1α expression (P = 0.028), high VEGF expression (P = 0.048), increased tumor angiogenesis (P = 0.033) and poor prognosis (P = 0.037); high MVD was associated with high HIF-1α expression (P = 0.034), high VEGF expression (P = 0.001) and poor prognosis (P = 0.040). Multivariate analysis indicated that RBP2 had an independent influence on the survival of patients with stage I NSCLC (P = 0.044). By modulating the expression of RBP2, our findings suggested that RBP2 protein depletion decreased HUVECs tube formation by down-regulating VEGF in a conditioned medium. RBP2 stimulated the up-regulation of VEGF, which was dependent on HIF-1α, and activated the HIF-1α via phosphatidylinositol 3-kinase (PI3K)/Akt signaling pathway. Moreover, VEGF increased the activation of Akt regulated by RBP2.

Conclusions

The RBP2 protein may stimulate HIF-1α expression via the activation of the PI3K/Akt signaling pathway under normoxia and then stimulate VEGF expression. These findings indicate that RBP2 may play a critical role in tumor angiogenesis and serve as an attractive therapeutic target against tumor aggressiveness for early-stage NSCLC patients.

Sputum interleukin-6, tumor necrosis factor-α and Salivary cortisol as new biomarkers of depression in lung cancer patients

Depression is common among lung cancer patients. Increasing evidence has suggested that hypothalamic-pituitary-adrenal (HPA) axis and pro-inflammatory cytokines may play a key role in the pathophysiology of depression as well as cancer. This pilot study investigated the efficacy of sputum interleukin (IL)-6, tumor necrosis factor (TNF)-α and salivary cortisol as new markers to support the diagnosis of depression in lung cancer patients. The diurnal rhythms of sputum IL-6, sputum TNF-α and salivary cortisol were measured in lung cancer patients with and without depression as well as depressed controls and healthy controls. The area under the diurnal variation curves (AUC) over the 24h time course and relative diurnal variation (VAR) were calculated. Receiver operating characteristic (ROC) analysis was performed. Patients with co-morbid depression and lung cancer showed highest level of sputum IL-6 AUC, sputum TNF-α AUC and lowest level of cortisol VAR (P<0.001). As a biomarker for depression, salivary cortisol VAR demonstrated an optimal cutoff point at 77.8% (AUC=0.94; 95% CI, 0.85-0.98), which is associated with a sensitivity of 82.1% and a specificity of 96.0%. Sputum IL-6 AUC demonstrated a sensitivity of 74.4% and a specificity of 92.0% (AUC=0.81; 95% CI, 0.69-0.90). These findings suggested that higher 24h overall levels of sputum IL-6, TNF-α and flattened diurnal salivary cortisol slopes were associated with depression in lung cancer patients. Sputum IL-6 AUC and salivary cortisol VAR performed best as biomarkers in the diagnosis of depression in lung cancer patients.

Immunotherapeutic approach for better management of cancer--role of IL-18

Interleukin-18 (IL-18) is an immune-stimulatory cytokine with antitumor activity in preclinical models. It plays pivotal roles in linking inflammatory immune responses and tumor progression and is a useful candidate in gene therapy of lymphoma or lymphoid leukemia. A phase I study of recombinant human IL-18 (rhIL-18) in patients with advanced cancer concluded that rhIL-18 can be safely given in biologically active doses to patients with advanced cancer. Some viruses can induce the secretion of IL-18 for immune evasion. The individual cytokine activity might be potentiated or inhibited by combinations of cytokines. Here we focus on combinational effects of cytokines with IL-18 in cancer progression. IL-18 is an important non-invasive marker suspected of contributing to metastasis. Serum IL-18 may a useful biological marker as independent prognostic factor of survival. In this review we cover roles of IL-18 in immune evasion, metastasis and angiogenesis, applications for chemotherapy and prognostic or diagnostic significance.

Betulinic acid decreases specificity protein 1 (Sp1) level via increasing the sumoylation of sp1 to inhibit lung cancer growth

Previous studies have shown that the inhibitory effect of betulinic acid (BA) on specificity protein 1 (Sp1) expression is involved in the prevention of cancer progression, but the mechanism of this effect remains to be delineated. In this study, we determined that BA treatment in HeLa cells increased the sumoylation of Sp1 by inhibiting sentrin-specific protease 1 expression. The subsequent recruitment of E3 ubiquitin-protein ligase RING finger protein 4 resulted in ubiquitin-mediated degradation in a 26S-proteosome-dependent pathway. In addition, both BA treatment and mithramycin A (MMA) treatment inhibited lung tumor growth and down-regulated Sp1 protein expression in Kras(G12D)-induced lung cancers of bitransgenic mice. In gene expression profiles of Kras(G12D)-induced lung cancers in bitransgenic mice with and without Sp1 inhibition, 542 genes were affected by MMA treatment. One of the gene products, cyclin A2, which was involved in the S and G(2)/M phase transition during cell cycle progression, was investigated in detail because its expression was regulated by Sp1. The down-regulation of cyclin A2 by BA treatment resulted in decreased retinoblastoma protein phosphorylation and cell cycle G(2)/M arrest. The BA-mediated cellular Sp1 degradation and antitumor effect were also confirmed in a xenograft mouse model by using H1299 cells. The knockdown of Sp1 in lung cancer cells attenuated the tumor-suppressive effect of BA. Taken together, the results of this study clarify the mechanism of BA-mediated Sp1 degradation and identify a pivotal role for Sp1 in the BA-induced repression of lung cancer growth.

Overexpression of human papillomavirus (HPV) type 16 oncoproteins promotes angiogenesis via enhancing HIF-1α and VEGF expression in non-small cell lung cancer cells

HPV-16 infection may play an important role in the development of non-small cell lung cancer (NSCLC) among never-smokers. Due to the critical role of angiogenesis in NSCLC development, we describe here the effect of HPV-16 oncoproteins on angiogenesis in NSCLC and the underlying mechanisms. We found that overexpression of HPV-16 E6 and E7 oncoproteins in NSCLC cells significantly promoted angiogenesis both in vitro and in vivo, and correspondingly, an enhanced expression of HIF-1α and VEGF, important pro-angiogenic factors in tumor angiogenesis. Meanwhile, overexpression of HPV-16 oncoproteins also led to HIF-1α-dependent increases in the secretion of several other pro-angiogenic factors, including IL-8. Our findings suggest that HPV-16 oncoproteins contribute to the development of NSCLC possibly by promoting HIF-1α/VEGF-mediated tumor angiogenesis.