Background
Exposure to environmental pollutants promotes Th2 cell responses. Aryl hydrocarbon receptor (AhR) activation aggravates allergic responses. Epithelium‐derived thymic stromal lymphopoietin ...(TSLP), interleukin (IL)‐25, and IL‐33 are implicated in the dysregulation of Th2 immune responses in severe allergic asthma.
Methods
Bronchial biopsies of 28 allergic severe asthma and 6 mild asthma subjects from highly polluted areas were analyzed for AhR nuclear translocation (NT), cytokine expression, and gene activation. Cultured primary epithelial cells were stimulated with diesel exhausted particles (DEP) to determine AhR‐mediated IL‐33, Il‐25, and TSLP synthesis and release.
Results
Primary bronchial epithelial cells exposed to DEP showed upregulation of IL‐33, IL‐25, and TSLP. These effects were abolished by knockdown of AhR by siRNA. Increased AhR/ARNT binding to promoters of IL‐33, IL‐25, and TSLP was found using chromatin immunoprecipitation (ChIP) assay. Allergic severe asthma with high AhR NT had higher bronchial gene and protein expression of IL‐33, IL‐25, and TSLP. These patients derived clinical benefit from anti‐IgE treatment.
Conclusion
Aryl hydrocarbon receptor activation by DEP mediates upregulation of IL‐33, IL‐25, and TSLP with Th2 activation, potentially linking environmental pollution and allergic severe asthma.
Environmental diesel exhaust particles (DEP) exposed to airway epithelium ligate cytoplasmic aryl hydrocarbon receptor (AhR), translocate to the nucleus with aryl hydrocarbon receptor nuclear translocator (ARNT), and then transactivate IL‐33, Il‐25, and TSLP gene expression. Patients with high AhR nucleus translocation overexpressed IL‐33, Il‐25, and TSLP cytokines compared to those with low. Patients with high AhR nucleus translocation are more response to anti‐IgE therapy compared to those with low.
Standard heat treatment (HT1) for Inconel 718 superalloy is solutionizing at 1095
°C, 1
h/AC, then aging at 955
°C, 1
h/AC
+
720
°C, 8
h/FC 57
K/h to 620
°C, 8
h/AC. In order to study the aging ...effects of the δ phase, two more conditions HT2 (no aging condition 955
°C) and HT3 (955
°C, 3.5
h/AC) were studied in this research. Lever arm creep tests were performed at 650
°C under constant stress 625
MPa. Since HT2 produces no δ phase, the stress rupture life, creep elongation to failure and steady state creep rate of HT2 are largest among these three aging conditions. However, increasing the 955
°C aging time, the stress rupture life, creep elongation and steady state creep rate raise slightly as compared to HT1, because platelet δ phase is more uniformly nucleated and more direction oriented at grain boundaries. Fractographs show ductile fracture patterns mostly and, small portion of inter-granular fracture in the HT2 specimens. Generally only inter-granular fracture is observed in the other two cases of HT1 and HT3. Besides twinning and dislocation mechanisms, grain boundary sliding is also activated, so that creep elongation to failure of HT2 specimens could reach 5.6%, whereas 1% for the other two schemes.
A number of patient-specific and leukemia-associated factors are related to the poor outcome in older patients with acute myeloid leukemia (AML). However, comprehensive studies regarding the impact ...of genetic alterations in this group of patients are limited. In this study, we compared relevant mutations in 21 genes between AML patients aged 60 years or older and those younger and exposed their prognostic implications. Compared with the younger patients, the elderly had significantly higher incidences of PTPN11, NPM1, RUNX1, ASXL1, TET2, DNMT3A and TP53 mutations but a lower frequency of WT1 mutations. The older patients more frequently harbored one or more adverse genetic alterations. Multivariate analysis showed that DNMT3A and TP53 mutations were independent poor prognostic factors among the elderly, while NPM1 mutation in the absence of FLT3/ITD was an independent favorable prognostic factor. Furthermore, the status of mutations could well stratify older patients with intermediate-risk cytogenetics into three risk groups. In conclusion, older AML patients showed distinct genetic alterations from the younger group. Integration of cytogenetics and molecular mutations can better risk-stratify older AML patients. Development of novel therapies is needed to improve the outcome of older patients with poor prognosis under current treatment modalities.
Vascular endothelial growth factor (VEGF) receptor 3 (VEGFR-3) (also called VEGFR-3) is activated by its specific ligand, VEGF-C, which promotes cancer progression. The VEGF-C/VEGFR-3 axis is ...expressed not only by lymphatic endothelial cells but also by a variety of human tumour cells. Activation of the VEGF-C/VEGFR-3 axis in lymphatic endothelial cells can facilitate metastasis by increasing the formation of lymphatic vessels (lymphangiogenesis) within and around tumours. The VEGF-C/VEGFR-3 axis plays a critical role in leukaemic cell proliferation, survival, and resistance to chemotherapy. Moreover, activation of the VEGF-C/VEGFR-3 axis in several types of solid tumours enhances cancer cell mobility and invasion capabilities, promoting cancer cell metastasis. In this review, we discuss the novel function and molecular mechanism of the VEGF-C/VEGFR-3 axis in cancer progression.
Conventionally, acute myeloid leukemia (AML) patients are categorized into good-, intermediate- and poor-risk groups according to cytogenetic changes. However, patients with intermediate-risk ...cytogenetics represent a largely heterogeneous population regarding treatment response and clinical outcome. In this study, we integrated cytogenetics and molecular mutations in the analysis of 318 patients with de novo non-M3 AML who received standard chemotherapy. According to the mutation status of eight genes, including NPM1, CEBPA, IDH2, RUNX1, WT1, ASXL1, DNMT3A and FLT3, that had prognostic significance, 229 patients with intermediate-risk cytogenetics could be refinedly stratified into three groups with distinct prognosis (P<0.001); patients with good-risk genotypes had a favorable outcome (overall survival, OS, not reached) similar to those with good-risk cytogenetics, whereas those with poor-risk genotypes had an unfavorable prognosis (OS, 10 months) similar to those with poor-risk cytogenetics (OS, 13.5 months), and the remaining patients with other genotypes had an intermediate outcome (OS, 25 months). Integration of cytogenetic and molecular profiling could thus reduce the number of intermediate-risk AML patients from around three-fourth to one-fourth. In conclusion, integration of cytogenetic and molecular changes improves the prognostic stratification of AML patients, especially those with intermediate-risk cytogenetics, and may lead to better decision on therapeutic strategy.
Summary
Recent studies have indicated that amino acid (aa) substitutions in the core region and NS5A interferon sensitivity‐determining region (ISDR) of hepatitis C virus (HCV) as well as genetic ...polymorphisms in the interleukin‐28B (IL‐28B) locus affect the outcome of interferon (IFN)‐based therapies. We aimed to investigate the role of these factors on response to peginterferon plus ribavirin in a prospective study of response‐guided therapy. The aa sequences in core region and ISDR and rs12979860 genotypes were analysed in 115 HCV‐1 patients. The treatment was 24 weeks for patients achieving a rapid virological response (RVR), 48 weeks for those with an early virological response (EVR) and early terminated in those without an EVR. A sustained virological response (SVR) was achieved in 82% of 34 RVR patients, 45% of 74 EVR patients and 0% of seven non‐EVR patients. Logistic regression analysis showed that ISDR mutation (≥2) odds ratio(OR): 6.024, double core 70/91 mutations (OR: 0.136), and platelet counts ≥ 15 × 104/μL (OR: 3.119) were independent pretreatment factors associated with SVR. Apart from rs12979860 CC genotype, low viral load and ISDR mutation (≥2) were significant factors predictive of RVR. Combination of rs12979860 genotype and baseline viral characteristics (viral load and core/ISDR mutations) could predict RVR and SVR with positive predictive value of 100% and 91%, and negative predictive value of 80% and 54%, respectively. In conclusion, pretreatment screening rs12979860 genotype and aa substitutions in the core region and ISDR could help identifying patients who are good candidates for peginterferon plus ribavirin therapy.
Receptor tyrosine kinases (RTKs) are cell surface receptors that initiate signal cascades in response to ligand stimulation. Abnormal expression and dysregulated intracellular trafficking of RTKs ...have been shown to be involved in tumorigenesis. Recent evidence shows that these cell surface receptors translocate from cell surface to different cellular compartments, including the Golgi, mitochondria, endoplasmic reticulum (ER) and the nucleus, to regulate physiological and pathological functions. Although some trafficking mechanisms have been resolved, the mechanism of intracellular trafficking from cell surface to the Golgi is not yet completely understood. Here we report a mechanism of Golgi translocation of epidermal growth factor receptor (EGFR) in which EGF-induced EGFR travels to the Golgi via microtubule-dependent movement by interacting with dynein and fuses with the Golgi through syntaxin 6-mediated membrane fusion. We also demonstrate that the microtubule- and syntaxin 6-mediated Golgi translocation of EGFR is necessary for its consequent nuclear translocation and nuclear functions. Thus, together with previous studies, the microtubule- and syntaxin 6-mediated trafficking pathway from cell surface to the Golgi, ER and the nucleus defines a comprehensive trafficking route for EGFR to travel from cell surface to the Golgi and the nucleus.
Background Amoxicillin‐resistant Helicobacter pylori with minimal inhibitory concentration (MIC) ≥ 256 mg L−1 was isolated from a gastritis patient. The aims were to investigate the mechanism of ...high‐level amoxicillin resistance in H. pylori.
Materials and methods The β‐lactamase production was determined by means of nitrocefin sticks and the presence of gene encoding the β‐lactam antibiotic resistance enzyme TEM β‐lactamase was analysed by polymerase chain reaction (PCR), sequencing and dot‐blot hybridization. Sequencing analysis of pbp1A gene was performed and amoxicillin‐susceptible isolate was transformed with pbp1A PCR products from the resistant isolate. The expression of hefC efflux system was analysed using real‐time quantitative PCR.
Results Activity of β‐lactamase was detected. Sequence analysis showed that the PCR product derived from H. pylori 3778 was identical to the blaTEM‐1 (GenBank accession EU726527). Dot‐blot hybridization confirmed the presence of β‐lactamase gene blaTEM‐1. By transformation of PCR product of mutated pbp1A gene from H. pylori 3778 into amoxicillin‐susceptible strain showed that substitutions in Thr556→Ser, Lys648→Gln, Arg649→Lys and Arg656→Pro contribute to low‐level amoxicillin resistance. The MIC of amoxicillin for the transformants was 0·75 mg L−1. Over‐expression of hefC was not found.
Conclusions High‐level amoxicillin resistance is associated with β‐lactamase production in H. pylori. Low‐level amoxicillin resistance is linked to a point mutation on pbp1A. Because H. pylori can exchange DNA through natural transformation, spreading of blaTEM‐1 amoxicillin resistance gene among H. pylori is a potential threat when treating H. pylori infection.
Metastasis is the predominant cause of death in breast cancer patients. Several lines of evidence have shown that microRNAs (miRs) can have an important role in cancer metastasis. Using isogenic ...pairs of low and high metastatic lines derived from a human breast cancer line, we have identified miR-149 to be a suppressor of breast cancer cell invasion and metastasis. We also identified GIT1 (G-protein-coupled receptor kinase-interacting protein 1) as a direct target of miR-149. Knockdown of GIT1 reduced migration/invasion and metastasis of highly invasive cells. Re-expression of GIT1 significantly rescued miR-149-mediated inhibition of cell migration/invasion and metastasis. Expression of miR-149 impaired fibronectin-induced focal adhesion formation and reduced phosphorylation of focal adhesion kinase and paxillin, which could be restored by re-expression of GIT1. Inhibition of GIT1 led to enhanced protein degradation of paxillin and α5β1 integrin via proteasome and lysosome pathways, respectively. Moreover, we found that GIT1 depletion in metastatic breast cancer cells greatly reduced α5β1-integrin-mediated cell adhesion to fibronectin and collagen. Low level of miR-149 and high level of GIT1 was significantly associated with advanced stages of breast cancer, as well as with lymph node metastasis. We conclude that miR-149 suppresses breast cancer cell migration/invasion and metastasis by targeting GIT1, suggesting potential applications of the miR-149-GIT1 pathway in clinical diagnosis and therapeutics.
Resveratrol, a phytochemical found in various plants and Chinese herbs, is associated with multiple tumor-suppressing activities, has been tested in clinical trials. However, the molecular mechanisms ...involved in resveratrol-mediated tumor suppressing activities are not yet completely defined. Here, we showed that treatment with resveratrol inhibited cell mobility through induction of the mesenchymal-epithelial transition (MET) in lung cancer cells. We also found that downregulation of FOXC2 (forkhead box C2) is critical for resveratrol-mediated suppression of tumor metastasis in an in vitro and in vivo models. We also identified a signal cascade, namely, resveratrol-∣miRNA-520h-∣PP2A/C-∣Akt → NF-κB → FOXC2, in which resveratrol inhibited the expression of FOXC2 through regulation of miRNA-520h-mediated signal cascade. This study identified a new miRNA-520h-related signal cascade involved in resveratrol-mediated tumor suppression activity and provide the clinical significances of miR-520h, PP2A/C and FOXC2 in lung cancer patients. Our results indicated a functional link between resveratrol-mediated miRNA-520h regulation and tumor suppressing ability, and provide a new insight into the role of resveratrol-induced molecular and epigenetic regulations in tumor suppression.
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