Sequential ubiquitination of p53 by TRIM28, RLIM, and MDM2 in lung tumorigenesis.

Tripartite motif-containing 28 (TRIM28) is an E3 ubiquitin ligase harboring multiple cellular functions. We found that the TRIM28 protein is frequently overexpressed in patients with lung cancer. The stable overexpression of TRIM28 in lung cancer cells and xenograft models significantly increased the proliferation, migration, and invasiveness, whereas knockdown of TRIM28 had the opposite effect. We further observed that TRIM28 regulates the ubiquitin ligases RLIM and MDM2 to target the p53 levels during lung tumorigenesis. These data provide new insights into lung cancer development and potential new therapeutic targets for this disease.

Hif-1α Inhibitors Could Successfully Inhibit the Progression of Differentiated Thyroid Cancer in Vitro.

Hypoxia-inducible factor (HIF)-1α plays an important role in cancer progression. In various cancers, including thyroid cancer, overexpression of HIF-1α is related to poor prognosis or treatment response. However, few studies have investigated the role of HIF-1α inhibition in thyroid cancer progression. We evaluated the utility of the HIF-1α inhibitor IDF-11774 in vitro utilizing two thyroid cancer cell lines, K1 and BCPAP. Both cell lines were tested to elucidate the effects of IDF-11774 on cell proliferation and migration using soft agar and invasion assays. Here, we found that a reduction of HIF-1α expression in BCPAP cells was observed after treatment with IDF-11774 in a dose-dependent manner. Moreover, cell proliferation, migration, and anchorage-independent growth were effectively inhibited by IDF-11774 in BCPAP cells but not in K1 cells. Additionally, invasion of BCPAP but not K1 cells was controlled with IDF-11774 in a dose-dependent manner. Our findings suggest that promoting the degradation of HIF-1α could be a strategy to manage progression and that HIF-1α inhibitors are potent drugs for thyroid cancer treatment.

USP14 Inhibition Regulates Tumorigenesis by Inducing Autophagy in Lung Cancer In Vitro.

The ubiquitin-proteasome system is an essential regulator of several cellular pathways involving oncogenes. Deubiquitination negatively regulates target proteins or substrates linked to both hereditary and sporadic forms of cancer. The deubiquitinating enzyme ubiquitin-specific protease 14 (USP14) is associated with proteasomes where it trims the ubiquitin chain on the substrate. Here, we found that USP14 is highly expressed in patients with lung cancer. We also demonstrated that USP14 inhibitors (IU1-47 and siRNA-USP14) significantly decreased cell proliferation, migration, and invasion in lung cancer. Remarkably, we found that USP14 negatively regulates lung tumorigenesis not only through apoptosis but also through the autophagy pathway. Our findings suggest that USP14 plays a crucial role in lung tumorigenesis and that USP14 inhibitors are potent drugs in lung cancer treatment.

Inhibition of peroxiredoxin 2 suppresses Wnt/ß-catenin signaling in gastric cancer.

Gastric cancer (GC) is the fourth most common type of malignant tumor that affects humans worldwide, but few targeted therapies for it have been considered that are based on redox systems. Peroxiredoxin2 (Prx2) functions as a reactive oxygen species (ROS)-mediated signaling regulator that controls H2O2 in mammalian cells, and it is involved in the survival of various malignant tumors. In human GC cells, Prx2 depletion markedly reduced the ß-catenin levels and expression of ß-catenin target genes and proteins. Cell-based assays demonstrated that Prx2 knockdown significantly ablates the cell viability, invasive activity, and colony-forming ability of both AGS and SNU668 cells. Furthermore, an experiment using conoidinA, a Prx2 inhibitor, revealed that Prx2 inhibition can overcome 5-FU resistance in GC cells. Thus, this study suggests that Prx2 plays a crucial role in regulating Wnt/ß-catenin signaling in GC cells.

Administration of Soft Matter Lipid-DNA Nanoparticle As the Immunostimulant via Multiple Routes of Injection in Vivo.

We elucidated the proper routes for injecting lipid-DNA micelles formulated with an oligonucleotide immune adjuvant in naïve and tumor-bearing mice. We report herein that after assessing six ways of administering an immunostimulatory nanoparticle (INP), several of the injection routes effectively induced dendritic cell-mediated immune-stimulation in vivo, making them amenable to cancer immunotherapies and vaccines using such DNA materials.

Neutrophilic inflammation in asthma: mechanisms and therapeutic considerations.

INTRODUCTION: Neutrophilic airway inflammation represents a pathologically distinct form of asthma and frequently appears in symptomatic adulthood asthmatics. However, clinical impacts and mechanisms of the neutrophilic inflammation have not been thoroughly evaluated up to date. Areas covered: Currently, distinct clinical manifestations, triggers, and molecular mechanisms of the neutrophilic inflammation (namely Toll-like receptor, Th1, Th17, inflammasome) are under investigation in asthma. Furthermore, possible role of the neutrophilic inflammation is being investigated in respect to the airway remodeling. We searched the related literatures published during the past 10 years on the website of Pub Med under the title of asthma and neutrophilic inflammation in human. Expert commentary: Epidemiologic and experimental studies have revealed that the neutrophilic airway inflammation is induced by a wide variety of stimuli including ozone, particulate matters, cigarette smoke, occupational irritants, endotoxins, microbial infection and colonization, and aeroallergens. These triggers provoke diverse immune and inflammatory responses leading to progressive and sometimes irreversible airway obstruction. Clinically, neutrophilic airway inflammation is frequently associated with severe asthma and poor response to glucocorticoid therapy, indicating the need for other treatment strategies. Accordingly, therapeutics will be targeted against the main mediators behind the underlying molecular mechanisms of the neutrophilic inflammation.

Circulating IL-33 level is associated with the progression of lung cancer.

OBJECTIVES: Interleukin (IL)-33 protects against infection and inflammation; however, few studies have explored the relevance of IL-33 in lung cancer patients. We evaluated relation of plasma IL-33 levels with development and progression of lung cancer. MATERIALS AND METHODS: A total of 160 patients with lung cancer and 160 controls with normal lungs were enrolled. Plasma IL-33 levels were measured using a specific sandwich ELISA; these levels were followed-up in 18 patients who underwent surgery and in 14 patients treated with chemotherapy. Malignant lesions and normal lung tissues from 10 cancer patients were subjected to immunohistochemical staining for IL-33. RESULTS: IL-33 levels were significantly lower in cancer patients than normal controls (0.08 vs. 0.38 ng/mL, p=0.005). Among cancer patients, IL-33 decreased in a stage-dependent manner from 0.76 ng/mL in stage I patients to 0.25 ng/mL in those with stage II, 0.08 ng/mL in those with stage III, and 0.08 ng/mL in those with stage IV (p=0.002). The levels were higher at stage I (p=0.041) and markedly lower at stages III and IV than those of controls (p=0.005 and p=0.001, respectively). A similar pattern was observed when IL-33 levels were analyzed by T stage; the levels were 0.39 ng/mL at T1/T2 vs. 0.08 ng/mL at T3/T4 (p=0.001). However, no difference was noted when stage N1 levels were compared with N2 and N3 levels (p=0.058), or between stage M0 and M1 levels (p=0.147). IL-33 levels gradually decreased after surgical resection of malignant lesions (from 1.075 to 0.756 ng/mL, p=0.006), but were unchanged after chemotherapy (0.705 vs. 0.829 ng/mL, p=0.875). On immunohistochemical staining, bronchial epithelial and vascular endothelial cells of normal lung tissues mainly expressed IL-33. CONCLUSIONS: Plasma IL-33 levels are associated inversely with progression of lung cancer. The observed decreases may be attributed to lung volume reduction containing bronchial epithelium and vascular endothelium as the sources of IL-33.

Elevation of S100 calcium binding protein A9 in sputum of neutrophilic inflammation in severe uncontrolled asthma.

BACKGROUND: Neutrophilic airway inflammation is frequently observed in severe uncontrolled asthma (UA) and controlled asthma (CA). However, there is no sputum biomarker to differentiate the 2 conditions. OBJECTIVE: To identify biomarkers of severe uncontrolled asthma with neutrophilic airway inflammation. METHODS: Sputum with a neutrophil content larger than 70% was pooled from 5 patients with severe UA and from 10 patients with CA. Two-dimensional electrophoresis was adopted for differential display proteomics, and candidate proteins were identified using matrix-assisted laser adsorption/ionization-time of flight mass spectrometric analysis. S100 calcium binding protein A9 (S100A9) was identified by western blot and its level was measured in sputum from asthmatics with varying disease severity, patients with chronic obstructive lung disease, and normal controls using enzyme-linked immunosorbent assay. RESULTS: Fourteen protein spots exhibited differences in relative intensity between patients with severe UA and those with CA. Matrix-assisted laser adsorption/ionization-time of flight/time of flight of these spots showed an increase in human neutrophil peptide-2, S100A9, ß-amylase, neutrophil gelatinase-associated lipocalin, 4-aminobutyrate transaminase, and cystatin SA in patients with UA compared with patients with CA. There was a decrease in the plunc precursor, complement C3 component, immunoglobulin heavy-chain variable region, glial fibrillary acidic protein isoform-1, IgM κIIIb SON, MLL-AF4 der(11) fusion protein, cytokeratin-8, and recombinant IgG4 heavy chain. S100A9 was detected at a higher level in western blots of neutrophilic sputum from patients with severe UA vs CA. S100A9 levels were significantly increased, as measured by enzyme-linked immunosorbent assay, in neutrophilic UA compared with CA, eosinophilic UA and CA, and chronic obstructive lung disease. CONCLUSION: S100A9 in sputum may be a biomarker of neutrophilic inflammation in severe UA.

Particle stimulation dephosphorylates glutathione S-transferase π1 of epithelial cells.

Environmental pollutant exposure is associated with adverse respiratory outcomes. The phosphorylation of enzymes activates or deactivates many cellular processes and is related to the development of lung diseases such as asthma and chronic obstructive pulmonary disease. However, little is known about protein phosphorylation of bronchial epithelial cells in response to airborne particulates. Herein, we screened differentially phosphorylated proteins in TiO2-treated epithelial cells and validated the change in GSTP1 protein phosphorylation. Two-dimensional electrophoresis was adopted for differential display proteomics of TiO2-treated BEAS-2B cell lysates. Phosphoproteins were screened using Pro-Q® Diamond phosphoprotein gel stain and identified by MALDI-TOF/TOF analysis. Immunoprecipitation and immunoblotting were performed for quantitative measurement of GSTP1 phosphorylation in cell lysates. Normalized relative intensities of nine phosphorylated proteins increased after TiO2 treatment, whereas those of 12 proteins decreased in the BEAS-2B cell lysates. From gene ontology and pathway analysis, proteins involved in signal transduction were commonly identified, followed by cytoskeletal proteins, proteins from oxidation and antioxidation pathways, proteins catalyzing reductions, and those involved in cellular process, transport, and modification. Immunoblotting with anti-GSTP1 antibody demonstrated no change in GSTP1 protein levels in the lysates of BEAS-2B cells after treatment with TiO2 particles; blotting with anti-phosphoserine and anti-phosphotyrosine antibodies showed dose-dependent decreases in phosphoserine and phosphotyrosine proteins. Stimulation with particulates phosphorylated and dephosphorylated several proteins in epithelial cells, and serine and tyrosine protein phosphorylation of GSTP1 decreased. These data indicate that airborne particles affect the pattern of phosphorylation of proteins involved in defense or apoptosis of respiratory epithelium.