Bee Venom Prevents Mucin 5AC Production through Inhibition of AKT and SPDEF Activation in Airway Epithelia Cells.

IL-13 induces mucus metaplasia, which causes airway obstruction in asthma. Bee venom (BV) and its components have shown anti-inflammatory effects in allergic diseases such as atopic dermatitis and asthma. In this study, we investigated the effect of BV on IL-13-induced mucus metaplasia through activation of the signal transducer and activator of transcription (STAT6), and regulation of SAM-pointed domain containing Ets-like factor (SPDEF) and forkhead box A2 (FOXA2) in the airway epithelia cell line A549. In A549 cells, BV (1.0 µg/mL) inhibited IL-13 (10 ng/mL)-induced AKT phosphorylation, increase in SPDEF protein expression, and decrease in FOXA2 protein expression-but not STAT6 phosphorylation. BV also prevented the IL-13-induced increase in mucin 5AC (MUC5AC) mRNA and protein expression. Moreover, we observed that inhibition of phosphoinositide 3 kinase (PI3K)/AKT using LY294002 (50 µM) could reverse the alterations in FOXA2 and MUC5AC expression -by IL-13 and BV. However, LY294002 did not affect IL-13- and BV-induced changes in SPDEF expression. These findings indicate that BV inhibits MUC5AC production through the regulation of SPDEF and FOXA2. The inhibition of MUC5AC production through FOXA2 is mediated via the suppression of PI3K/AKT activation by BV. BV may be helpful in the prevention of mucus metaplasia in asthma.

H1-Receptor Antagonist Olopatadine Inhibits MUC5AC Secretion by Conjunctival Goblet Cells.

The study examined the effect of H1-receptor antagonist olopatadine on the secretory function of cultured rat conjunctival goblet cells (CGC) assessed by enzyme-linked lectin assay employing UEA-I lectin. The level of mRNA for membrane-bound protein MUC16 in histaminestimulated CGC was assayed by reverse transcription PCR in the control and after preliminary application of olopatadine. The intracellular calcium concentration [Ca2+]i was measured by the calcium colorimetric method using GENMED kits. The effects of histamine and olopatadine on p-ERK level were assessed by Western blotting. Histamine up-regulated secretion of mucin MUC5AC and expression of membrane-bound protein MUC16 in CGC. In addition, it increased both [Ca2+]i and the level of phosphorylated ERK. These effects were diminished by preliminary application of olopatadine that probably acted via the ERK signaling pathway. Thus, olopatadine reduced [Ca2+]i and down-regulated ERK phosphorylation by binding to H1-receptors, thereby inhibiting secretion of mucin from histamine-stimulated CGC.

Resveratrol inhibits MUC5AC expression by regulating SPDEF in lung cancer cells.

BACKGROUND: MUC5AC was recently identified to play important roles in the proliferation and metastasis of malignant mucinous lung tumor cells. Resveratrol (Res), a natural compound with anticancer effects in lung cancer cells, has been reported to inhibit mucin production in airway epithelial cells. This study aimed to investigate the inhibitory effect of Res on MUC5AC expression in lung mucinous adenocarcinoma cells and the potential mechanisms. METHODS: Mucus-producing A549 human lung carcinoma cells were used to test the effects of Res on SPDEF and MUC5AC expression. Gene and protein expression was assessed by real-time quantitative PCR (qPCR), immunofluorescence and western blotting assays. SPDEF lentivirus was used to upregulate SPDEF expression levels in mucus-producing A549 human lung carcinoma cells. Cell proliferation was assessed by Cell Counting Kit-8 (CCK-8) assay. RESULTS: Res decreased MUC5AC expression in an SPDEF-dependent manner in mucus-producing A549 human lung carcinoma cells, and this change was accompanied by decreased ERK expression and AKT pathway activation. Moreover, SPDEF was found to be overexpressed in lung adenocarcinoma (LUAD), especially in mucinous adenocarcinoma. In-vitro functional assays showed that overexpression of SPDEF reduced the chemosensitivity of A549 cells to cisplatin (DDP). In addition, Res treatment increased A549 cell chemosensitivity to DDP by inhibiting the SPDEF-MUC5AC axis. CONCLUSION: Our results indicate that the SPDEF-MUC5AC axis is associated with DDP sensitivity, and that Res decreases SPDEF and MUC5AC expression by inhibiting ERK and AKT signaling in A549 cells, which provides a potential pharmacotherapy for the prevention and therapeutic management of mucinous adenocarcinoma.

Bisacodyl Suppresses TGF-α-Induced MUC5AC Production in NCI-H292 Cells.

MUC5AC overproduction is commonly observed in chronic inflammatory lung diseases and worsens these conditions. Therefore, drugs that inhibit MUC5AC production are urgently needed. To identify novel drugs directly inhibiting MUC5AC production, 640 already approved drugs were screened. We found that the laxative bisacodyl suppressed transforming growth factor (TGF)-α-induced MUC5AC production in a concentration-dependent manner. Additionally, bisacodyl also suppressed TGF-α-induced MUC5AC mRNA expression in the same concentration range. These results suggested that bisacodyl could be a new drug for treating mucin overproduction.

Investigation of the Active Ingredients and Mechanism of Polygonum cuspidatum in Asthma Based on Network Pharmacology and Experimental Verification.

BACKGROUND: Polygonum cuspidatum is a Chinese medicine commonly used to treat phlegm-heat asthma. However, its anti-asthmatic active ingredients and mechanism are still unknown. The aim of this study was to predict the active ingredients and pathways of Polygonum cuspidatum and to further explore the potential molecular mechanism in asthma by using network pharmacology. METHODS: The active ingredients and their targets related to Polygonum cuspidatum were seeked out with the TCM systematic pharmacology analysis platform (TCMSP), and the ingredient-target network was constructed. The GeneCards, DrugBank and OMIM databases were used to collect and screen asthma targets, and then the drug-target-disease interaction network was constructed with Cytoscape software. A target protein-protein interaction (PPI) network was constructed using the STRING database to screen key targets. Finally, GO and KEGG analyses were used to identify biological processes and signaling pathways. The anti-asthmatic effects of Polygonum cuspidatum and its active ingredients were tested in vitro for regulating airway smooth muscle (ASM) cells proliferation and MUC5AC expression, two main symptoms of asthma, by using Real-time PCR, Western blotting, CCK-8 assays and annexin V-FITC staining. RESULTS: Twelve active ingredients in Polygonum cuspidatum and 479 related target proteins were screened in the relevant databases. Among these target proteins, 191 genes had been found to be differentially expressed in asthma. PPI network analysis and KEGG pathway enrichment analysis predicted that the Polygonum cuspidatum could regulate the AKT, MAPK and apoptosis signaling pathways. Consistently, further in vitro experiments demonstrated that Polygonum cuspidatum and resveratrol (one active ingredient of Polygonum cuspidatum) were shown to inhibit ASM cells proliferation and promoted apoptosis of ASM cells. Furthermore, Polygonum cuspidatum and resveratrol inhibited PDGF-induced AKT/mTOR activation in ASM cells. In addition, Polygonum cuspidatum decreased H2O2 induced MUC5AC overexpression in airway epithelial NCI-H292 cells. CONCLUSION: Polygonum cuspidatum could alleviate the symptoms of asthma including ASM cells proliferation and MUC5AC expression through the mechanisms predicted by network pharmacology, which provides a basis for further understanding of Polygonum cuspidatum in the treatment of asthma.

Ibudilast Suppresses MUC5AC Mucus Production through Inhibition of ERK1/2 Phosphorylation.

Mucus hypersecretion is a hallmark of respiratory diseases, and excess airway mucus can worsen these conditions. Therefore, it is important to control the production of airway mucus in the treatment of respiratory diseases. The phosphodiesterase inhibitor ibudilast has been reported to be effective in treating sputum and postnasal drip in patients with chronic airway inflammation. On the basis of the hypothesis that ibudilast could inhibit mucus production in the airway, in the present study, we examined the effects of ibudilast on the production of MUC5AC, a major protein component of mucus. In in vitro studies using NCI-H292 cells, ibudilast suppressed MUC5AC production induced by various stimuli. In addition, ibudilast inhibited extracellular signal-regulated kinase (ERK)1/2 phosphorylation and MUC5AC gene transcription. Furthermore, it attenuated MUC5AC production and Muc5ac mRNA expression in lipopolysaccharide-treated mice in vivo. Collectively, these findings demonstrate that ibudilast has an inhibitory effect on mucus production, which could at least partly be attributed to the inhibition of ERK1/2 phosphorylation and the repression of MUC5AC gene transcription.

Phloretin, an Apple Polyphenol, Inhibits Pathogen-Induced Mucin Overproduction.

SCOPE: Bacterial infection induces mucus overproduction, contributing to acute exacerbations and lung function decline in chronic respiratory diseases. A diet enriched in apples may provide protection from pulmonary disease development and progression. This study examined whether phloretin, an apple polyphenol, inhibits mucus synthesis and secretion induced by the predominant bacteria associated with chronic respiratory diseases. METHODS AND RESULTS: The expression of mucus constituent mucin 5AC (MUC5AC) in FVB/NJ mice and NCI-H292 epithelial cells is analyzed. Nontypeable Haemophilus influenzae (NTHi)-infected mice developed increased MUC5AC mRNA, which a diet containing phloretin inhibited. In NCI-H292 cells, NTHi, Moraxella catarrhalis, Streptococcus pneumoniae, and Pseudomonas aeruginosa increased MUC5AC mRNA, which phloretin inhibited. Phloretin also diminished NTHi-induced MUC5AC protein secretion. NTHi-induced increased MUC5AC required toll-like receptor 4 (TLR4) and NADH oxidase 4 (NOX4) signaling and subsequent activation of the epidermal growth factor receptor (EGFR)/mitogen-activated protein kinase (MAPK) pathway. Phloretin inhibited NTHi-induced TLR4/NOX4 and EGFR/MAPK signaling, thereby preventing increased MUC5AC mRNA. EGFR activation can also result from increased EGFR ligand synthesis and subsequent ligand activation by matrix metalloproteinases (MMPs). In NCI-H292 cells, NTHi increased EGFR ligand and MMP1 and MMP13 mRNA, which phloretin inhibited. CONCLUSIONS: In summary, phloretin is a promising therapeutic candidate for preventing bacterial-induced mucus overproduction.

Phase II Study of Ensituximab, a Novel Chimeric Monoclonal Antibody, in Adults with Unresectable, Metastatic Colorectal Cancer.

PURPOSE: Patients with metastatic colorectal cancer refractory to chemotherapy have limited treatment options. Ensituximab (NEO-102) is a novel chimeric mAb targeting a variant of MUC5AC with specificity to colorectal cancer. PATIENTS AND METHODS: Single-arm, phase II trial assessed the efficacy and safety of ensituximab in patients with advanced, refractory cancer who expressed MUC5AC antigen in tumor tissue. Ensituximab was administered intravenously every 2 weeks with 3 mg/kg as recommended phase II dose (RP2D). A minimum sample size of 43 patients was required on the basis of the assumption that ensituximab would improve median overall survival (OS) by 7 months using a one-sided significance level of 10% and 80% power. Written informed consent was obtained from all patients. RESULTS: Sixty-three patients with advanced, refractory colorectal cancer were enrolled and 53 subjects were treated in phase II arm. Median age was 58 years and 46% of the patients were female. Among 57 evaluable patients, median OS was 6.8 months. No responses were observed, and stable disease was achieved in 21% of the patients. The most common treatment-related adverse events (AE) at RP2D included fatigue (38%), anemia (30%), nausea (15%), vomiting (11%), increased bilirubin (9%), constipation (8%), decreased appetite (6%), and diarrhea (6%). Serious AEs at least possibly related to ensituximab occurred in 4 patients and included anemia, nausea, increased bilirubin, and hypoxia. No patients discontinued treatment due to drug-related AEs. CONCLUSIONS: Ensituximab was well tolerated and demonstrated modest antitumor activity in patients with heavily pretreated refractory colorectal cancer.

Arsenic represses airway epithelial mucin expression by affecting retinoic acid signaling pathway.

Arsenic is a ubiquitous environmental toxicant, found in high concentrations worldwide. Although abundant research has dealt with arsenic-induced cancers, studies on mechanisms of non-malignant lung diseases have not been complete. In addition, decades of research have mostly concentrated on high-dose arsenic exposure, which has very limited use in modeling the biological effects of today's low-dose exposures. Indeed, accumulated evidence has shown that low-dose arsenic exposure (i.e. ≤100 ppb) may also alter lung homeostasis by causing host susceptibility to viral infection. However, the underlying mechanism of this alteration is unknown. In this study, we found that low-dose sodium arsenite (As (III)) repressed major airway mucins-MUC5AC and MUC5B at both mRNA and protein levels. We further demonstrated that this repression was not caused by cellular toxicity or mediated by the reduction of a common mucin-inducing pathway-EGFR. Other established mucin activators- dsRNA, IL1ß or IL17 were not able to override As (III)-induced mucin repression. Interestingly, the suppressing effect of As (III) appeared to be partially reversible, and supplementation of all trans retinoic acid (t-RA) doses dependently restored mucin gene expression. Further analyses indicated that As (III) treatment significantly reduced the protein level of retinoic acid receptors (RARα, γ and RXRα) as well as RARE promoter reporter activity. Therefore, our study fills in an important knowledge gap in the field of low-dose arsenic exposure. The interference of RA signaling, and mucin gene expression may be important pathogenic factors in low-dose arsenic induced lung toxicity.

DFSG, a novel herbal cocktail with anti-asthma activity, suppressed MUC5AC in A549 cells and alleviated allergic airway hypersensitivity and inflammatory cell infiltration in a chronic asthma mouse model.

AIM OF THE STUDY: To develop a novel anti-asthma drug. DFSG is a novel herbal cocktail composed of 4 types of herbal medicines. This study explored whether DFSG has the potential to attenuate asthma symptom severity and aimed to determine the immunomodulatory mechanism of DFSG using a chronic asthmatic mouse model induced by repeated challenges with Dermatogoides pteronyssinus (Der p). MATERIALS AND METHODS: BALB/c mice were intratracheally inoculated with Der p (50 µl, 1 mg/ml) once a week for 5 weeks. In addition, 30 min before Der p challenge, the mice were orally administered 1x DFSG (1 g/kg) or 1/2x DFSG (0.5 g/kg). Three days after the final challenge, the mice were sacrificed to evaluate inflammatory cell infiltration, lung histological features, blood total IgE, and cytokine levels in pulmonary alveolar lavage fluid. Furthermore, 30 min after the addition of DFSG, caffeic acid, p-coumaric acid or chlorogenic acid to A549 cells, 10 ng/ml IL-1ß was added to evaluate the effect of the drug on mucin 5AC (MUC5AC) gene expression after stimulation of A549 cells by IL-1ß. RESULTS: DFSG significantly reduced Der p-induced airway hyperresponsiveness, bronchial inflammatory cell infiltration, and total IgE and IgG1 serum levels. Furthermore, DFSG significantly inhibited TH2 cytokines and increased the expression of TH1 cytokines. In addition, immunohistochemical staining demonstrated that DFSG inhibited MUC5AC expression in the bronchial epithelial cells. DFSG and a mixture of caffeic acid, p-coumaric acid, and chlorogenic acid inhibited MUC5AC gene expression in A549 cells after stimulation with IL-1ß. CONCLUSION: These results suggest that by regulating TH1 and TH2 cytokines and MUC5AC expression, DFSG exhibits anti-airway inflammatory cell infiltration and anti-hyperresponsiveness activity and inhibits specific immunity in a chronic asthmatic mouse model. Therefore, DFSG has potential for development into a drug for chronic asthma treatment.

Natural inhibitors on airway mucin: Molecular insight into the therapeutic potential targeting MUC5AC expression and production.

Airway mucin overproduction is the hallmark risk factor of asthma, which is associated with the reduction of lung function. An aberrant mucin expression is responsible for airway obstruction due to its high viscous characteristics. Among the mucins discovered, MUC5AC is the prime mucin of airway epithelia. Nowadays, mucins induced asthma and chronic obstructive pulmonary disease (COPD) are a great concern all over the world. This review focuses on the effects of natural compounds that can be beneficial to explore new drugs to halt MUC5AC secretion and production in airway epithelial, and also their underlying molecular mechanisms based on recent studies. Several researchers are seeking natural sources to identify a new potent MUC5AC inhibitory agent for clinical applications, because of countable limitations of existing synthetic drugs. Currently, flavonoids, glycoside and steroids like natural compounds have acquired great attention due to their anti-inflammatory and mucoregulatory effects. Most importantly, many natural compounds have shown their potential effects as the modulator of mucin expression, secretion, and production. Therefore, targeting airway MUC5AC expression and production represents an auspicious area of research for the development of drugs against various respiratory diseases.

Plantamajoside Inhibits Lipopolysaccharide-Induced MUC5AC Expression and Inflammation through Suppressing the PI3K/Akt and NF-κB Signaling Pathways in Human Airway Epithelial Cells.

It has been reported that plantamajoside (PMS), a major natural compound isolated from Plantago asiatica, has anti-inflammatory activities. However, the effect of PMS on respiratory inflammatory diseases has not yet been studied. The present study aimed to evaluate the effect of PMS on lipopolysaccharide (LPS)-induced airway inflammation and the underlying mechanism. The results showed that PMS did not affect the cell viability of 16-HBE cells. PMS (20 and 40 µg/ml) decreased the expression levels of MUC5AC, IL-6, and IL-1ß, which were induced by LPS treatment. PMS inhibited the LPS-induced phosphorylation of Akt and p65. In addition, inhibitors of the PI3K/Akt and NF-κB pathways attenuated the effect of LPS on 16-HBE cells. In conclusion, PMS inhibits LPS-induced MUC5AC expression and inflammation through suppressing the PI3K/Akt and NF-κB signaling pathways, indicating that PMS may be a potential therapy for the treatment of respiratory inflammatory diseases.

Evaluating the Toxicity of Cigarette Whole Smoke Solutions in an Air-Liquid-Interface Human In Vitro Airway Tissue Model.

Exposure to cigarette smoke causes a multitude of pathological changes leading to tissue damage and disease. Quantifying such changes in highly differentiated in vitro human tissue models may assist in evaluating the toxicity of tobacco products. In this methods development study, well-differentiated human air-liquid-interface (ALI) in vitro airway tissue models were used to assess toxicological endpoints relevant to tobacco smoke exposure. Whole mainstream smoke solutions (WSSs) were prepared from 2 commercial cigarettes (R60 and S60) that differ in smoke constituents when machine-smoked under International Organization for Standardization conditions. The airway tissue models were exposed apically to WSSs 4-h per day for 1-5 days. Cytotoxicity, tissue barrier integrity, oxidative stress, mucin secretion, and matrix metalloproteinase (MMP) excretion were measured. The treatments were not cytotoxic and had marginal effects on tissue barrier properties; however, other endpoints responded in time- and dose-dependent manners, with the R60 resulting in higher levels of response than the S60 for many endpoints. Based on the lowest effect dose, differences in response to the WSSs were observed for mucin induction and MMP secretion. Mitigation of mucin induction by cotreatment of cultures with N-acetylcysteine suggests that oxidative stress contributes to mucus hypersecretion. Overall, these preliminary results suggest that quantifying disease-relevant endpoints using ALI airway models is a potential tool for tobacco product toxicity evaluation. Additional research using tobacco samples generated under smoking machine conditions that more closely approximate human smoking patterns will inform further methods development.

NPS2143 Inhibits MUC5AC and Proinflammatory Mediators in Cigarette Smoke Extract (CSE)-Stimulated Human Airway Epithelial Cells.

Mucus overproduction is a fundamental hallmark of COPD that is caused by exposure to cigarette smoke. MUC5AC is one of the main mucin genes expressed in the respiratory epithelium, and its transcriptional upregulation often correlates with increased mucus secretion. Calcium-sensing receptor (CaSR) antagonists have been reported to possess anti-inflammatory effects. The purpose of the present study was to investigate the protective role of NPS2143, a selective CaSR antagonist on cigarette smoke extract (CSE)-stimulated NCI-H292 mucoepidermoid human lung cells. Treatment of NPS2143 significantly inhibited the expression of MUC5AC in CSE-stimulated H292 cells. NPS2143 reduced the expression of MMP-9 in CSE-stimulated H292 cells. NPS2143 also decreased the release of proinflammatory cytokines such as IL-6 and TNF-α in CSE-stimulated H292 cells. Furthermore, NPS2143 attenuated the activation of MAPKs (JNK, p38, and ERK) and inhibited the nuclear translocation of NF-κB in CSE-stimulated H292 cells. These results indicate that NPS2143 had a therapeutic potential in COPD.

Depletion of mucin in mucin-producing human gastrointestinal carcinoma: Results from in vitro and in vivo studies with bromelain and N-acetylcysteine.

Aberrant expression of membrane-associated and secreted mucins, as evident in epithelial tumors, is known to facilitate tumor growth, progression and metastasis, and to provide protection against adverse growth conditions, chemotherapy and immune surveillance. Emerging evidence provides support for the oncogenic role of MUC1 in gastrointestinal carcinomas and relates its expression to an invasive phenotype. Similarly, mucinous differentiation of gastrointestinal tumors, in particular increased or de novo expression of MUC2 and/or MUC5AC, is widely believed to imply an adverse clinicopathological feature. Through formation of viscous gels, too, MUC2 and MUC5AC significantly contribute to the biology and pathogenesis of mucin-secreting gastrointestinal tumors. Here, we investigated the mucin-depleting effects of bromelain (BR) and N-acetylcysteine (NAC), in nine different regimens as single or combination therapy, in in vitro (MKN45, KATOIII and LS174T cell lines) and in vivo (female nude mice bearing intraperitoneal MKN45 and LS174T) settings. The inhibitory effects of the treatment on cancer cell growth and proliferation were also evaluated in vivo. Our results suggest that a combination of BR and NAC with dual effects on growth and mucin products of mucin-expressing tumor cells is a promising candidate towards the development of novel approaches to gastrointestinal malignancies with the involvement of mucin pathology. This capability supports the use of this combination formulation in locoregional approaches for reducing the adverse effects of the aberrantly secreted gel-forming mucins, as in pseudomyxoma peritonei and similar pathologies with ectopic production of mucin.

6-Mercaptopurine reduces cytokine and Muc5ac expression involving inhibition of NFκB activation in airway epithelial cells.

BACKGROUND: Mucus hypersecretion and excessive cytokine synthesis is associated with many of the pathologic features of chronic airway diseases such as asthma. 6-Mercaptopurine (6-MP) is an immunosuppressive drug that is widely used in several inflammatory disorders. Although 6-MP has been used to treat asthma, its function and mechanism of action in airway epithelial cells is unknown. METHODS: Confluent NCI-H292 and MLE-12 epithelial cells were pretreated with 6-MP followed by stimulation with TNFα or PMA. mRNA levels of cytokines and mucins were measured by RT-PCR. Western blot analysis was performed to assess the phosphorylation of IκBα and luciferase assays were performed using an NFκB reporter plasmid to determine NFκB activity. Periodic Acid Schiff staining was used to assess the production of mucus. RESULTS: 6-MP displayed no effect on cell viability up to a concentration of 15 µM. RT-PCR analysis showed that 6-MP significantly reduces TNFα- and PMA-induced expression of several proinflammatory cytokines in NCI-H292 and MLE-12 cells. Consistent with this, we demonstrated that 6-MP strongly inhibits TNFα-induced phosphorylation of IκBα and thus attenuates NFκB luciferase reporter activity. In addition, 6-MP decreases Rac1 activity in MLE-12 cells. 6-MP down-regulates gene expression of the mucin Muc5ac, but not Muc2, through inhibition of activation of the NFκB pathway. Furthermore, PMA- and TNFα-induced mucus production, as visualized by Periodic Acid Schiff (PAS) staining, is decreased by 6-MP. CONCLUSIONS: Our data demonstrate that 6-MP inhibits Muc5ac gene expression and mucus production in airway epithelial cells through inhibition of the NFκB pathway, and 6-MP may represent a novel therapeutic target for mucus hypersecretion in airway diseases.

Phloretin inhibits interleukin-1ß-induced COX-2 and ICAM-1 expression through inhibition of MAPK, Akt, and NF-κB signaling in human lung epithelial cells.

Phloretin, a flavonoid isolated from the apple tree, is reported to have anti-inflammatory, anti-oxidant, and anti-adiposity effects. In this study, we evaluated the suppressive effects of phloretin on intercellular adhesion molecule 1 (ICAM-1) and cyclooxygenase (COX)-2 expression in IL-1ß-stimulated human lung epithelial A549 cells. The cells were pretreated with various concentrations of phloretin (3-100 µM), followed by induced inflammation by IL-1ß. Phloretin inhibited levels of prostaglandin E2, decreased COX-2 expression, and suppressed IL-8, monocyte chemotactic protein 1, and IL-6 production. It also decreased ICAM-1 gene and protein expression and suppressed monocyte adhesion to inflammatory A549 cells. Phloretin also significantly inhibited Akt and mitogen-activated protein kinase (MAPK) phosphorylation and decreased nuclear transcription factor kappa-B (NF-κB) subunit p65 protein translocation into the nucleus. In addition, ICAM-1 and COX-2 expression was suppressed by pretreatment with both MAPK inhibitors and phloretin in inflammatory A549 cells. However, phlorizin, a derivative of phloretin, did not suppress the inflammatory response in IL-1ß-stimulated A549 cells. These results suggest that phloretin might have an anti-inflammatory effect by inhibiting proinflammatory cytokine, COX-2, and ICAM-1 expression via blocked NF-κB and MAPK signaling pathways.

Suppressive effects of coixol, glyceryl trilinoleate and natural products derived from Coix Lachryma-Jobi var. ma-yuen on gene expression, production and secretion of airway MUC5AC mucin.

In this study, we investigated whether natural products including coixol derived from Coix Lachryma-Jobi var. ma-yuen affect MUC5AC mucin gene expression, production and secretion from airway epithelial cells. Confluent NCI-H292 cells were pretreated with oleic acid, linoleic acid, glyceryl trilinoleate, beta-stigmasterol or coixol for 30 min and then stimulated with PMA (phorbol 12-myristate 13-acetate), EGF (epidermal growth factor) or TNF-α (tumor necrosis factor-α) for 24 h. The MUC5AC mucin gene expression, mucin protein production and secretion were measured by RT-PCR and ELISA. The results were as follows: (1) Oleic acid, linoleic acid, glyceryl trilinoleate, beta-stigmasterol and coixol inhibited the expression of MUC5AC mucin gene induced by PMA from NCI-H292 cells; (2) Oleic acid, linoleic acid, glyceryl trilinoleate, beta-stigmasterol and coixol also inhibited the production of MUC5AC mucin protein induced by the same inducers from NCI-H292 cells; (3) Coixol inhibited the expression of MUC5AC mucin gene and production of MUC5AC mucin protein, induced by EGF or TNF-α from NCI-H292 cells; (4) Coixol decreased PMA-induced MUC5AC mucin secretion from NCI-H292 cells. This result suggests that coixol, the characteristic component among the examined five natural products derived from C. Lachryma-Jobi var. ma-yuen, can regulate gene expression, production and secretion of mucin, by directly acting on airway epithelial cells.

Novel agents for the treatment of pancreatic cancer.

Metastatic pancreatic cancer continues to be a difficult disease to treat because of its aggressive nature, advanced stage at presentation and lack of treatment options. There is a need for the development of new agents directed against novel targets to improve outcomes for these patients. At the 2014 American Society of Clinical Oncology (ASCO) Gastrointestinal Cancers Symposium phase I/II trials provided information on three novel strategies for treating metastatic pancreatic cancer. Immunotherapy in the form of a vaccine (GVAX) followed with an immune stimulator (CRS-207) showed extended survival (Abstract #177). A monoclonal antibody (NEO-102) targeting MUC5AC also showed activity and was well tolerated (Abstract #243). A heat shock protein 90 (HSP90) inhibitor (ganetespib) showed modest effects but was well tolerated making it available for use with conventional chemotherapy (Abstract #297). The details of these presentations will be discussed.

Transient receptor potential vanilloid 1 receptors mediate acid-induced mucin secretion via Ca2+ influx in human airway epithelial cells.

Mucin hypersecretion is a key pathological feature of inflammatory respiratory diseases. Previous studies have reported that acids (gastroesophageal reflux or environmental exposure) induce many respiratory symptoms and are implicated in the pathophysiology of obstructive airway diseases. To understand these mechanisms, we measured acid-induced mucin secretion in human bronchial epithelial cells. In the present study, acid induced inward currents of transient receptor potential vanilloid (TRPV)1 and mucin 5AC (MUC5AC) secretion dose dependently, which were inhibited by TRPV1 antagonist capsazepine in a concentration-dependent manner. TRPV1 agonist capsaicin mediated a concentration-dependent increase in TRPV1 inward currents and MUC5AC secretion. Furthermore, capsaicin enhanced acid-induced TRPV1 inward currents and MUC5AC secretion. Acid-induced Ca(2+) influx was prevented by capsazepine dose dependently and enhanced by capsaicin. Pretreatment only with capsaicin also increased the Ca(2+) concentration in a concentration-dependent manner. These data suggest that pharmacological inhibition of calcium-permeable TRPV1 receptors could be used to prevent acid-induced mucin secretion, thereby providing a potential mechanism to reduce their toxicity.