46 research outputs found

    Dual EZH2 and EHMT2 histone methyltransferase inhibition increases biological efficacy in breast cancer cells

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    Background: Many cancers show aberrant silencing of gene expression and overexpression of histone methyltransferases. The histone methyltransferases (HKMT) EZH2 and EHMT2 maintain the repressive chromatin histone methylation marks H3K27me and H3K9me, respectively, which are associated with transcriptional silencing. Although selective HKMT inhibitors reduce levels of individual repressive marks, removal of H3K27me3 by specific EZH2 inhibitors, for instance, may not be sufficient for inducing the expression of genes with multiple repressive marks. Results: We report that gene expression and inhibition of triple negative breast cancer cell growth (MDA-MB-231) are markedly increased when targeting both EZH2 and EHMT2, either by siRNA knockdown or pharmacological inhibition, rather than either enzyme independently. Indeed, expression of certain genes is only induced upon dual inhibition. We sought to identify compounds which showed evidence of dual EZH2 and EHMT2 inhibition. Using a cell-based assay, based on the substrate competitive EHMT2 inhibitor BIX01294, we have identified proof-of-concept compounds that induce re-expression of a subset of genes consistent with dual HKMT inhibition. Chromatin immunoprecipitation verified a decrease in silencing marks and an increase in permissive marks at the promoter and transcription start site of re-expressed genes, while Western analysis showed reduction in global levels of H3K27me3 and H3K9me3. The compounds inhibit growth in a panel of breast cancer and lymphoma cell lines with low to sub-micromolar IC50s. Biochemically, the compounds are substrate competitive inhibitors against both EZH2 and EHMT1/2. Conclusions: We have demonstrated that dual inhibition of EZH2 and EHMT2 is more effective at eliciting biological responses of gene transcription and cancer cell growth inhibition compared to inhibition of single HKMTs, and we report the first dual EZH2-EHMT1/2 substrate competitive inhibitors that are functional in cells

    Examining exposure of motorcycles at signalized intersections

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    Crash statistics in Singapore from 2001 to 2005 have shown that motorcycles are involved in about 54% of intersection crashes. The overall involvement of motorcycles in crashes as the not-at-fault party is about 43% but at intersections, the corresponding percentage is increased to 57%. Quasi-induced exposure estimates show that the motorcycle exposure rate at signalized intersections is 41.7% even though motorcycles account for only 19% of the vehicle population. This study seeks to examine in greater details, the problem of motorcycle exposure at signalized intersections. In particular, the exposure arising from potential crashes with red light running vehicles from the conflicting stream at four signalized intersections is investigated. The results show that motorcycles are more exposed because they tend to accumulate near the stop-line during the red phase to facilitate an earlier discharge during the initial period of the green which is the more vulnerable period. At sites where there are more weaving opportunities because the lanes are wider or where there are exclusive right-turn lanes, the accumulation is higher and hence an increased exposure is observed. The analysis also shows that the presence of heavy vehicles tends to decrease motorcycle exposure as their weaving opportunities become restricted as well as there is a greater reluctance for them to weave past or queue alongside the heavy vehicles and their effects intensify for narrower lane width

    Increased efficacy of omalizumab in atopic dermatitis patients with wild-type filaggrin status and higher serum levels of phosphatidycholines.

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    Omalizumab, a monoclonal antibody targeting IgE, is an established therapy for severe allergic asthma and has shown efficacy in chronic spontaneous urticaria. Small-scale studies indicated some beneficial effect also in atopic dermatitis (AD). To evaluate the efficacy of omalizumab in AD and to identify markers associated with treatment response, we conducted a prospective 28-week open-label trial on 20 adults with moderate-to-severe AD. Our results confirm previous observations of a positive response in a subgroup of patients and suggest that responders are characterized by the absence of filaggrin mutations and altered lipid metabolite profiles with high levels of various glycerophospholipids

    On the determination of the stereochemistry of semisynthetic natural product analogues using chiroptical spectroscopy : desulfurization of epidithiodioxopiperazine fungal metabolites

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    Isolation and semisynthetic modification of the fungal metabolite chaetocin gave access to a desulfurized analogue of this natural product. Detailed chiroptical studies, comparing experimentally obtained optical rotation values, electronic circular dichroism spectra, and vibrational circular dichroism spectra to computationally simulated ones, reveal the desulfurization of chaetocin to unambiguously proceed with retention of configuration. Consideration of the plausible mechanisms for this process highlighted inconsistencies in the stereochemical assignment of related molecules in the literature. This in turn allowed the stereochemical reassignment of the natural product analogue dethiodehydrogliotoxin

    Chronic inducible urticaria (CIndU) in Europe, Central America, and South America: findings from visit 1 of the worldwide aware study

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    Charite, Allergie Ctr Charite ECARF, Dept Dermatol & Allergy, Berlin, GermanyHosp Gen Plaza Salud, Santo Domingo, Dominican RepNovartis Pharma AG, Basel, SwitzerlandUniv Fed São Paulo, Sau Paulo, BrazilUniv Santo Amaro, Sau Paulo, BrazilCtr Hosp Univ Poitiers, Serv Dermatol, Poitiers, FranceRTI Hlth Solut, Res Triangle Pk, NC USAVall Dhebron Hosp, Internal Med, Barcelona, SpainUniv Manchester, Salford Royal NHS Fdn Trust, Salford, Lancs, EnglandRTI Hlth Solut, Manchester, Lancs, EnglandSOD Immunoallergy Careggi Univ Hosp, Florence, ItalyHosp Arnau Vilanova, Dermatol Dept, Valencia, SpainUniv Fed São Paulo, Sau Paulo, BrazilWeb of Scienc

    Healthcare resource utilisation due to chronic urticaria in Europe, South America, and Central America: findings from visit 1 of the worldwide aware study

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    Charite, Dept Dermatol & Allergy, Allergie Ctr Charite ECARF, Berlin, GermanyHosp Gen Plaza Salud, Santo Domingo, Dominican RepNovartis Pharma AG, Basel, SwitzerlandUniv Fed São Paulo, Sau Paulo, BrazilUniv Santo Amaro, Sau Paulo, BrazilCtr Hosp Univ Poitiers, Serv Dermatol, Poitiers, FranceRTI Hlth Solut, Res Triangle Pk, NC USAVall dHebron Hosp, Internal Med, Barcelona, SpainUniv Manchester, Salford Royal NHS Fdn Trust, Salford, Lancs, EnglandRTI Hlth Solut, Manchester, Lancs, EnglandCareggi Univ Hosp, SOD Immunoallergy, Florence, ItalyHosp Arnau Vilanova, Dept Dermatol, Valencia, SpainUniv Fed São Paulo, Sau Paulo, BrazilWeb of Scienc

    Differences in chronic spontaneous urticaria between Europe and Central/South America : results of the multi-center real world AWARE study

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    Global chronic urticaria (CU) disease experience and management is not well documented. This study descriptively compares these aspects among CU patients residing in Europe (EU) and Central and South America (C/SA). AWARE (A World-wide Antihistamine-Refractory chronic urticaria patient Evaluation) is a global prospective, non-interventional study of CU in the real-world setting. Patients were ≥ 18 years with a diagnosis of H1-antihistamine-refractory CU for > 2 months. Differences between the EU and C/SA regions in demographic and clinical characteristics, quality of life (QoL), work and activity impairment, pharmacological treatment, and healthcare resource use were examined. In total, 4224 patients were included in the analysis (C/SA 492; EU 3732). Rates of untreated patients were greater in the C/SA region (45.1% vs. 31.9%; P < 0.005) and escalation to third-line therapy was rare in both regions. Differences in disease experience emerged, with C/SA patients more commonly experiencing angioedema (C/SA 50.8% vs. EU 46.1%; P = 0.03) or comorbid chronic inducible urticaria (C/SA 30% vs. EU 22%; P < 0.001). Correspondingly, rates of uncontrolled urticaria were higher among C/SA patients (82.8% vs. 77.5%; P = 0.017) and patients in the C/SA region showed significantly greater work and activity impairment (absenteeism: 10.4 ± 19.7 vs. 6.7 ± 19.0, P = 0.004; presenteeism: 30.3 ± 31.9 vs. 24.4 ± 25.8, P = 0.001; work productivity loss: 33.9 ± 33.9 vs. 26.5 ± 27.5, P < 0.001; activity impairment: 37.7 ± 34.7 vs. 32.7 ± 30.1, P = 0.001). However, QoL impairment was greater in the EU region (Dermatology Life Quality Index: C/SA 6.5 ± 5.9 vs. EU 8.3 ± 7.0; P < 0.001). There was a significant difference in use of healthcare resources, including emergency services (39.6% vs. 29.3%; P < 0.001), hospitalization (7.7% vs 21.9%; P < 0.001) general practitioners (31.7% vs 57.3%; P < 0.001), and additional allergists or dermatologists (50.6% vs. 47.3%, P < 0.001), among patients in the C/SA and EU region, respectively. In both regions, patients with a primary diagnosis of CU with angioedema had significantly greater impairment in work and non-work activities and healthcare resource utilization compared to those without angioedema. This study revealed that CU is a heterogeneous condition with differences in healthcare utilization and outcomes between EU and C/SA. However, overall there is a high unmet need of H1-antihistamine-refractory CU patients, which is associated with high use of healthcare resources, and has a large negative effect on QoL and work productivity
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