Bronchodilation induced by PGE2 is impaired in Group-III pulmonary hypertension

BACKGROUND AND PURPOSE: In patients with pulmonary hypertension (PH) associated with lung disease and/or hypoxia (Group III), a reduction of pulmonary vascular tone and tissue hypoxia are considered therapeutically beneficial. Prostaglandin (PG) E2 and PGI2 induce potent relaxation of human bronchi from non-PH (control) patients via EP4 and IP receptors, respectively. However, the effects of PGE2 /PGI2 and their mimetics on human bronchi from PH-patients are unknown. Our aim was to compare the relaxant effects of several PGI2 -mimetics approved for treating PH-Group I with several PGE2 -mimetics in bronchial preparations derived from PH-Group III and control patients. EXPERIMENTAL APPROACH: Using an organ bath system, the tone of bronchial muscle was investigated in tissue from either control or PH-Group III patients. Expression of prostanoid receptors were analyzed by Western blot and real-time PCR and endogenous PGE2 , PGI2 and cAMP levels were determined by ELISA. KEY RESULTS: Maximal relaxations induced by different EP4 agonists (PGE2 , L-902688, ONO-AE1-329) were significantly decreased in human bronchi from PH-patients versus controls. In contrast, the maximal relaxations produced by PGI2 -mimetics (iloprost, treprostinil, beraprost) were similar for both groups of patients. Both EP4 and IP receptor protein and mRNA expressions were significantly lower in human bronchi from PH-patients. cAMP levels significantly correlated with PGI2 but not with PGE2 levels. CONCLUSION AND IMPLICATIONS: This study shows that PGI2 -mimetics have preserved maximal bronchodilation in PH-Group III patients. The decreased bronchodilation induced by EP4 agonists suggests that restoration of EP4 expression in airways of PH-patients with respiratory diseases could bring additional therapeutic benefit

Fermionic Coset, Critical Level W^(2)_4-Algebra and Higher Spins

The fermionic coset is a limit of the pure spinor formulation of the AdS5xS5 sigma model as well as a limit of a nonlinear topological A-model, introduced by Berkovits. We study the latter, especially its symmetries, and map them to higher spin algebras. We show the following. The linear A-model possesses affine \AKMSA{pgl}{4}{4}_0 symmetry at critical level and its \AKMSA{psl}{4}{4}_0 current-current perturbation is the nonlinear model. We find that the perturbation preserves $\mathcal{W}^{(2)}_4$-algebra symmetry at critical level. There is a topological algebra associated to \AKMSA{pgl}{4}{4}_0 with the properties that the perturbation is BRST-exact. Further, the BRST-cohomology contains world-sheet supersymmetric symplectic fermions and the non-trivial generators of the $\mathcal{W}^{(2)}_4$-algebra. The Zhu functor maps the linear model to a higher spin theory. We analyze its \SLSA{psl}{4}{4} action and find finite dimensional short multiplets.Comment: 25 page

Combinatorial CRISPR-Cas9 screens for de novo mapping of genetic interactions.

We developed a systematic approach to map human genetic networks by combinatorial CRISPR-Cas9 perturbations coupled to robust analysis of growth kinetics. We targeted all pairs of 73 cancer genes with dual guide RNAs in three cell lines, comprising 141,912 tests of interaction. Numerous therapeutically relevant interactions were identified, and these patterns replicated with combinatorial drugs at 75% precision. From these results, we anticipate that cellular context will be critical to synthetic-lethal therapies

High TWIST1 mRNA expression is associated with poor prognosis in lymph node-negative and estrogen receptor-positive human breast cancer and is co-expressed with stromal as well as ECM related genes

Introduction: The TWIST homolog 1 (TWIST1) is a transcription factor that induces epithelial to mesenchymal transition (EMT), a key process in metastasis. The purpose of this study was to investigate whether TWIST1 expression predicts disease progression in a large breast cancer cohort with long-term clinical follow-up, and to reveal the biology related to TWIST1 mediated disease progression.Methods: TWIST1 mRNA expression level was analyzed by quantitative real-time reverse polymerase chain reaction (RT-PCR) in 1,427 primary breast cancers. In uni- and multivariate analysis using Cox regression, TWIST1 mRNA expression level was associated with metastasis-free survival (MFS), disease-free survival (DFS) and overall survival (OS). Separate analyses in lymph node-negative patients (LNN, n = 778) who did not receive adjuvant systemic therapy, before and after stratification into estrogen receptor (ER)-positive (n = 552) and ER-negative (n = 226) disease, were also performed. The association of TWIST1 mRNA with survival endpoints was assessed using Kaplan-Meier analysis. Using gene expression arrays, genes showing a significant Spearman rank correlation with TWIST1 were used to identify overrepresented Gene Ontology (GO) terms and Kyoto Encyclopedia of Genes and Genomes (KEGG)-annotated biological pathways.Results: Increased mRNA expression level of TWIST1 analyzed as a continuous variable in both uni- and multivariate analysis was associated with shorter MFS in all patients (hazard ratio (HR): 1.17, 95% confidence interval, (95% CI):1.09 to 1.26; and HR: 1.17, 95% CI: 1.08 to 1.26; respectively), in LNN patients (HR: 1.22, 95% CI: 1.09 to 1.36; and HR: 1.21, 95% CI: 1.07 to 1.36; respectively) and in the ER-positive subgroup of LNN patients (HR: 1.34, 95% CI: 1.17 to 1.53; and HR: 1.32, 95% CI: 1.14 to 1.53; respectively). Similarly, high TWIST1 expression was associated with shorter DFS and OS in all patients and in the LNN/ER-positive subgroup. In contrast, no association of TWIST1 mRNA expression with MFS, DFS or OS was observed in ER-negative patients. Genes h

Early indicators of exposure to biological threat agents using host gene profiles in peripheral blood mononuclear cells

<p>Abstract</p> <p>Background</p> <p>Effective prophylaxis and treatment for infections caused by biological threat agents (BTA) rely upon early diagnosis and rapid initiation of therapy. Most methods for identifying pathogens in body fluids and tissues require that the pathogen proliferate to detectable and dangerous levels, thereby delaying diagnosis and treatment, especially during the prelatent stages when symptoms for most BTA are indistinguishable flu-like signs.</p> <p>Methods</p> <p>To detect exposures to the various pathogens more rapidly, especially during these early stages, we evaluated a suite of host responses to biological threat agents using global gene expression profiling on complementary DNA arrays.</p> <p>Results</p> <p>We found that certain gene expression patterns were unique to each pathogen and that other gene changes occurred in response to multiple agents, perhaps relating to the eventual course of illness. Nonhuman primates were exposed to some pathogens and the <it>in vitro</it> and <it>in vivo</it> findings were compared. We found major gene expression changes at the earliest times tested post exposure to aerosolized <it>B. anthracis </it>spores and 30 min post exposure to a bacterial toxin.</p> <p>Conclusion</p> <p>Host gene expression patterns have the potential to serve as diagnostic markers or predict the course of impending illness and may lead to new stage-appropriate therapeutic strategies to ameliorate the devastating effects of exposure to biothreat agents.</p

Markers of Tumor-Initiating Cells Predict Chemoresistance in Breast Cancer

PURPOSE: Evidence is lacking whether the number of breast tumor-initiating cells (BT-ICs) directly correlates with the sensitivity of breast tumors to chemotherapy. Here, we evaluated the association between proportion of BT-ICs and chemoresistance of the tumors. METHODS: Immunohistochemical staining(IHC) was used to examine the expression of aldehyde dehydrogenase 1 (ALDH1) and proliferating cell nuclear antigen, and TUNEL was used to detect the apoptosis index. The significance of various variables in patient survival was analyzed using a Cox proportional hazards model. The percentage of BT-ICs in breast cancer cell lines and primary breast tumors was determined by ALDH1 enzymatic assay, CD44(+)/CD24(-) phenotype and mammosphere formation assay. RESULTS: ALDH1 expression determined by IHC in primary breast cancers was associated with poor clinical response to neoadjuvant chemotherapy and reduced survival in breast cancer patients. Breast tumors that contained higher proportion of BT-ICs with CD44(+)/CD24(-) phenotype, ALDH1 enzymatic activity and sphere forming capacity were more resistant to neoadjuvant chemotherapy. Chemoresistant cell lines AdrR/MCF-7 and SK-3rd, had increased number of cells with sphere forming capacity, CD44(+)/CD24(-) phenotype and side-population. Regardless the proportion of T-ICs, FACS-sorted CD44(+)/CD24(-) cells that derived from primary tumors or breast cancer lines were about 10-60 fold more resistant to chemotherapy relative to the non- CD44(+)/CD24(-) cells and their parental cells. Furthermore, our data demonstrated that MDR1 (multidrug resistance 1) and ABCG2 (ATP-binding cassette sub-family G member 2) were upregulated in CD44(+)/CD24(-) cells. Treatment with lapatinib or salinomycin reduced the proportion of BT-ICs by nearly 50 fold, and thus enhanced the sensitivity of breast cancer cells to chemotherapy by around 30 fold. CONCLUSIONS: These data suggest that the proportion of BT-ICs is associated with chemotherapeutic resistance of breast cancer. It highlights the importance of targeting T-ICs, rather than eliminating the bulk of rapidly dividing and terminally differentiated cells, in novel anti-cancer strategies

A Mechanistic Basis for the Coordinated Regulation of Pharyngeal Morphogenesis in Caenorhabditis elegans by LIN-35/Rb and UBC-18–ARI-1

Genetic redundancy, whereby two genes carry out seemingly overlapping functions, may in large part be attributable to the intricacy and robustness of genetic networks that control many developmental processes. We have previously described a complex set of genetic interactions underlying foregut development in the nematode Caenorhabditis elegans. Specifically, LIN-35/Rb, a tumor suppressor ortholog, in conjunction with UBC-18–ARI-1, a conserved E2/E3 complex, and PHA-1, a novel protein, coordinately regulates an early step of pharyngeal morphogenesis involving cellular re-orientation. Functional redundancy is indicated by the observation that lin-35; ubc-18 double mutants, as well as certain allelic combinations of pha-1 with either lin-35 or ubc-18, display defects in pharyngeal development, whereas single mutants do not. Using a combination of genetic and molecular analyses, we show that sup-35, a strong recessive suppressor of pha-1–associated lethality, also reverts the synthetic lethality of lin-35; ubc-18, lin-35; pha-1, and ubc-18 pha-1 double mutants. SUP-35, which contains C2H2-type Zn-finger domains as well as a conserved RMD-like motif, showed a dynamic pattern of subcellular localization during embryogenesis. We find that mutations in sup-35 specifically suppress hypomorphic alleles of pha-1 and that SUP-35, acting genetically upstream of SUP-36 and SUP-37, negatively regulates pha-1 transcription. We further demonstrate that LIN-35, a transcriptional repressor, and UBC-18–ARI-1, a complex involved in ubiquitin-mediated proteolysis, negatively regulate SUP-35 abundance through distinct mechanisms. We also show that HCF-1, a C. elegans homolog of host cell factor 1, functionally antagonizes LIN-35 in the regulation of sup-35. Our cumulative findings piece together the components of a novel regulatory network that includes LIN-35/Rb, which functions to control organ morphogenesis. Our results also shed light on general mechanisms that may underlie developmental genetic redundancies as well as principles that may govern complex disease traits

Mesenchymal and stemness circulating tumor cells in early breast cancer diagnosis

<p>Abstract</p> <p>Background</p> <p>Epithelial mesenchymal transition (EMT) is a crucial event likely involved in dissemination of epithelial cancer cells. This process enables them to acquire migratory/invasive properties, contributing to tumor and metastatic spread. To know if this event is an early one in breast cancer, we developed a clinical trial. The aim of this protocol was to detect circulating tumor cells endowed with mesenchymal and/or stemness characteristics, at the time of initial diagnosis. Breast cancer patients (n = 61), without visceral or bone metastasis were enrolled and analysis of these dedifferentiated circulating tumor cells (ddCTC) was realized.</p> <p>Methods</p> <p><it>AdnaGen </it>method was used for enrichment cell selection. Then, ddCTC were characterized by RT-PCR study of the following genes: PI3Kα, Akt-2, Twist1 (EMT markers) and ALDH1, Bmi1 and CD44 (stemness indicators).</p> <p>Results</p> <p>Among the studied primary breast cancer cohort, presence of ddCTC was detected in 39% of cases. This positivity is independant from tumor clinicopathological factors apart from the lymph node status.</p> <p>Conclusions</p> <p>Our data uniquely demonstrated that <it>in vivo </it>EMT occurs in the primary tumors and is associated with an enhanced ability of tumor cells to intravasate in the early phase of cancer disease. These results suggest that analysis of circulating tumor cells focused on cells showing mesenchymal or stemness characteristics might facilitate assessment of new drugs in clinical trials.</p

Two-Component Elements Mediate Interactions between Cytokinin and Salicylic Acid in Plant Immunity

Recent studies have revealed an important role for hormones in plant immunity. We are now beginning to understand the contribution of crosstalk among different hormone signaling networks to the outcome of plant–pathogen interactions. Cytokinins are plant hormones that regulate development and responses to the environment. Cytokinin signaling involves a phosphorelay circuitry similar to two-component systems used by bacteria and fungi to perceive and react to various environmental stimuli. In this study, we asked whether cytokinin and components of cytokinin signaling contribute to plant immunity. We demonstrate that cytokinin levels in Arabidopsis are important in determining the amplitude of immune responses, ultimately influencing the outcome of plant–pathogen interactions. We show that high concentrations of cytokinin lead to increased defense responses to a virulent oomycete pathogen, through a process that is dependent on salicylic acid (SA) accumulation and activation of defense gene expression. Surprisingly, treatment with lower concentrations of cytokinin results in increased susceptibility. These functions for cytokinin in plant immunity require a host phosphorelay system and are mediated in part by type-A response regulators, which act as negative regulators of basal and pathogen-induced SA–dependent gene expression. Our results support a model in which cytokinin up-regulates plant immunity via an elevation of SA–dependent defense responses and in which SA in turn feedback-inhibits cytokinin signaling. The crosstalk between cytokinin and SA signaling networks may help plants fine-tune defense responses against pathogens