Zirconaaziridine-Mediated Ni-Catalyzed Diastereoselective C(sp2)-Glycosylation.

In the realm of organic synthesis, the catalytic and stereoselective formation of C-glycosidic bonds is a pivotal process, bridging carbohydrates with aglycones. However, the inherent chirality of the saccharide scaffold often has a substantial impact on the stereoinduction imposed by a chiral ligand. In this study, we have established an unprecedented zirconaaziridine-mediated asymmetric nickel catalysis, enabling the diastereoselective coupling of bench-stable glycosyl phosphates with a range of (hetero)aromatic and glycal iodides as feasible coupling electrophiles. Our developed method showcases a broad scope and a high tolerance for various functional groups. More importantly, precise stereocontrol toward both anomeric configurations of forming C(sp2)-glycosides can be realized by simply utilizing the popular chiral bioxazoline (biOx) ligands in this reductive Ni catalysis. Regarding the operating mechanism, both experimental and computational studies support the occurrence of a redox transmetalation process, leading to the formation of a transient, bimetallic Ni-Zr species that acts as a potent and efficient single-electron reductant in the catalytic process.

Associations between metabolic syndrome and anthropogenic heat emissions in northeastern China.

BACKGROUND: Recent research attention has been paid to anthropogenic heat emissions (AE), temperature increase generated by human activity such as lighting, transportation, manufacturing, construction, and building climate controls. However, there is no epidemiological data available to investigate the association between anthropogenic heat emissions and metabolic syndrome (MetS), a cluster of conditions that increase risk of stroke, heart disease and diabetes. OBJECTIVE: To explore the relationships between AE and MetS in China. METHODS: We recruited 15,477 adults from the 33 Communities Chinese Health Study, a cross-sectional study in northeastern China. We retrieved anthropogenic heat flux by collecting socio-economic and energy consumption data as well as satellite-based nighttime light and Normalized Difference Vegetation Index datasets, including emissions from buildings, transportation, human metabolism, and industries. We also measured MetS components consisting of triglycerides, high density lipoprotein cholesterol, fasting glucose, systolic blood pressure, and diastolic blood pressure, and waist circumference. Restricted cubic spline models were applied to assess the associations between AE and MetS. RESULTS: The median flux of total AE was 30.98 W/m2 and industrial AE was the dominant contributor (87.64%). The adjusted odds ratio and 95% confidence interval (CI) of MetS for the 75th and 95th percentiles of the total AE against the threshold were 1.29 (95% CI: 1.21, 1.38) and 1.65 (95% CI: 1.47, 1.85). Greater AE was associated with higher odds of MetS in a dose-response pattern, and the lowest point of U-shape curve indicated the threshold effect. Participants who are young and middle-aged exhibited stronger associations between AE and MetS. CONCLUSIONS: Our novel findings reveal that AE are positively associated with MetS and that associations are modified by age. Further investigations into the mechanisms of the effects are needed.

Aurora kinase inhibitor restrains STAT5-activated leukemic cell proliferation by inducing mitochondrial impairment.

Current chemotherapy regimens on acute myeloid leukemia (AML) still have some drawbacks, such as intolerance and drug resistance, which calls need for the development of targeted therapy. Signal transducer and activator of transcription 5 (STAT5) is often overexpressed or abnormally activated in leukemia and involved in cell self-renewal, proliferation, and stress adaptation. Overexpressed Aurora A (AURKA) is associated with poor prognosis in tumors, and inhibitors against AURKA are already in clinical trials. However, it has rarely been reported whether AURKA inhibitors restrain STAT5-activated leukemia cells. In this study, we constructed STAT5 constitutively activated (cS5) cells and found that STAT5 promoted cell proliferation and colony formation. Moreover, cS5 cells showed elevated reactive oxygen species (ROS) and adenosine triphosphate (ATP) levels, which indicated higher mitochondrial metabolism in cS5 cells. A novel AURKA inhibitor AKI604 was synthesized and showed significant inhibitory effects to the proliferation and colony formation in both STAT5 constitutively activated and nonactivated AML cells. AKI604 induced mitochondrial impairment, leading to the disruption of mitochondrial membrane potential and the elevation of ROS as well as cellular calcium (Ca2+ ) levels. AKI604 could also decline basal oxygen consumption rate and ATP biosynthesis, indicating the damage of oxidative phosphorylation. Furthermore, AKI604 exhibited significant antitumor effect in the HL-60 cS5 xenograft model of the BALB/c nude mice without an obvious influence on mice body weight and other healthy indicators. This study suggested that AKI604 was a potential strategy to overcome STAT5-induced leukemic proliferation in AML treatment by inducing mitochondrial impairment.

Accumulation of the delivered dose based on cone-beam CT and deformable image registration for non-small cell lung cancer treated with hypofractionated radiotherapy.

BACKGROUND: This study aimed to quantify the dosimetric differences between the planned and delivered dose to tumor and normal organs in locally advanced non-small cell lung cancer (LANSCLC) treated with hypofractionated radiotherapy (HRT), and to explore the necessity and identify optimal candidates for adaptive radiotherapy (ART). METHODS: Twenty-seven patients with stage III NSCLC were enrolled. Planned radiation dose was 51Gy in 17 fractions with cone-beam CT (CBCT) acquired at each fraction. Virtual CT was generated by deformable image registration (DIR) of the planning CT to CBCT for dose calculation and accumulation. Dosimetric parameters were compared between original and accumulated plans using Wilcoxon signed rank test. Correlations between dosimetric differences and clinical variables were analyzed using Mann-Whitney U test or Chi-square test. RESULTS: Patients had varied gross tumor volume (GTV) reduction by HRT (median reduction rate 11.1%, range - 2.9-44.0%). The V51 of planning target volume for GTV (PTV-GTV) was similar between original and accumulated plans (mean, 88.2% vs. 87.6%, p = 0.452). Only 11.1% of patients had above 5% relative decrease in V51 of PTV-GTV in accumulated plans. Compared to the original plan, limited increase (median relative increase < 5%) was observed in doses of total lung (mean dose, V20 and V30), esophagus (mean dose, maximum dose) and heart (mean dose, V30 and V40) in accumulated plans. Less than 30% of patients had above 5% relative increase of lung or heart doses. Patients with quick tumor regression or baseline obstructive pneumonitis showed more notable increase in doses to normal structures. Patients with baseline obstructive atelectasis showed notable decrease (10.3%) in dose coverage of PTV-GTV. CONCLUSIONS: LANSCLC patients treated with HRT had sufficient tumor dose coverage and acceptable normal tissue dose deviation. ART should be applied in patients with quick tumor regression and baseline obstructive pneumonitis/atelectasis to spare more normal structures.

Establishment of a risk model correlated with metabolism based on RNA-binding proteins associated with cell pyroptosis in acute myeloid leukemia.

Background: RNA-binding protein (RBP) regulates acute myeloid leukemia (AML) by participating in mRNA editing and modification. Pyroptosis also plays an immunomodulatory function in AML. Therefore, this study aimed to identify pyroptosis-related RBP genes that could predict the prognosis of AML patients. Methods: AML related expression data were downloaded from the UCSC website and Gene Expression Omnibus (GEO) database. Pyroptosis-RPB-related differentially expressed genes (PRBP-DEGs) were conducted with a protein-protein interactions (PPI) network to screen out the key PRBP-DEGs, based on which a risk model was constructed by Cox analysis, and evaluated by plotting Receiver operating characteristic (ROC) curves and survival curves. Independent prognostic analysis was performed and a nomogram was constructed. Finally, enrichment analysis was performed for high and low risk groups. Reuslts: A total of 71 PRBP-DEGs were obtained and a pyroptosis-RPB-related risk model was constructed based on IFIT5, MRPL14, MRPL21, MRPL39, MVP, and PUSL1 acquired from Cox analysis. RiskScore, age, and cytogenetics risk category were identified as independent prognostic factors, and the nomogram based on these independent prognostic factors could accurately predict 1-, 3- and 5-year survival of AML patients. Gene set enrichment analysis (GSEA) showed that the high-risk and low-risk groups were mainly enriched in metabolic- and immune-related processes and pathways. Conclusion: In this study, a risk score model correlated with metabolism based on RNA-binding proteins associated with cell pyroptosis in acute myeloid leukemia was established, which provided a theoretical basis and reference value for therapeutic studies and prognosis of AML.

Regulation of autophagy and lipid accumulation under phosphate limitation in Rhodotorula toruloides.

Background: It is known that autophagy is essential for cell survival under stress conditions. Inorganic phosphate (Pi) is an essential nutrient for cell growth and Pi-limitation can trigger autophagy and lipid accumulation in oleaginous yeasts, yet protein (de)-phosphorylation and related signaling events in response to Pi limitation and the molecular basis linking Pi-limitation to autophagy and lipid accumulation remain elusive. Results: Here, we compared the proteome and phosphoproteome of Rhodotorula toruloides CGMCC 2.1389 under Pi-limitation and Pi-repletion. In total, proteome analysis identified 3,556 proteins and the phosphoproteome analysis identified 1,649 phosphoproteins contained 5,659 phosphosites including 4,499 pSer, 978 pThr, and 182 pTyr. We found Pi-starvation-induced autophagy was regulated by autophagy-related proteins, but not the PHO pathway. When ATG9 was knocked down, the engineered strains produced significantly less lipids under Pi-limitation, suggesting that autophagy required Atg9 in R. toruloides and that was conducive to lipid accumulation. Conclusion: Our results provide new insights into autophagy regulation under Pi-limitation and lipid accumulation in oleaginous yeast, which should be valuable to guide further mechanistic study of oleaginicity and genetic engineering for advanced lipid producing cell factory.

Fabrication of magnetic covalent organic framework for effective and selective solid-phase extraction of propylparaben from food samples.

Efficient magnetic solid phase extraction using crystalline porous polymers can find important applications in food safety. Herein, the core-shell Fe3O4@COFs nanospheres were synthesized by one-pot method and characterized in detail. The porous COF shell with large surface area had fast and selective adsorption for propylparaben via π-π, hydrogen bonding and hydrophobic interactions. The extraction and desorption parameters were evaluated in detail. Under the optimized conditions, the extraction equilibrium was reached only in 5 min, the maximum adsorption capacity for propylparaben was 500 mg g-1 and the proposed Fe3O4@DhaTab-based-MSPE-HPLC-UV method afforded good linearity (4-20000 µg mL-1) with R2 (0.997), low limits of detection (0.55 µg L-1) and limits of quantification (1.5 µg L-1). Furthermore, the developed method was applied to determine propylparaben in soft drinks with the recoveries (97.0-98.3%) and relative standard deviations (0.61 to 3.75%). These results revealed the potential of Fe3O4@DhaTab as efficient adsorbents for parabens in food samples.

Zirconium-Redox-Shuttled Cross-Electrophile Coupling of Aromatic and Heteroaromatic Halides.

Transition metal-catalyzed cross-electrophile coupling (XEC) is a powerful tool for forging C(sp2)-C(sp2) bonds in biaryl molecules from abundant aromatic halides. While syntheses of unsymmetrical biaryl compounds through multimetallic XEC is of high synthetic value, selective XEC of two heteroaromatic halides remains elusive and challenging. Herein we report a homogeneous XEC method which relies on a zirconaaziridine complex as a shuttle for dual palladium catalyzed processes. The zirconaaziridine-mediated palladium (ZAPd) catalyzed reaction shows excellent compatibility with various functional groups and diverse heteroaromatic scaffolds. In accord with density functional theory (DFT) calculations, a redox-transmetallation between the oxidative addition product and the zirconaaziridine is proposed as the crucial elementary step. Thus, cross-coupling selectivity using a single transition metal catalyst is controlled by the relative rate of oxidative addition of Pd(0) into the aromatic halide. Overall, the concept of a combined reducing and transmetallating agent offers opportunities for development of transition-metal reductive coupling catalysis.

Docetaxel and nedaplatin twice a week with concurrent definitive radiotherapy in inoperable esophageal squamous cell carcinoma: A phase I trial (GASTO-1021).

PURPOSE: This phase I trial aimed to determine the maximal tolerated dose (MTD) of incorporating a twice-weekly docetaxel and nedaplatin regimen into definitive concurrent chemoradiotherapy (CCRT) as radiosensitizers in patients with inoperable esophageal squamous cell carcinoma (ESCC). METHODS: The CCRT regimen included docetaxel (5 mg/m2, 10 mg/m2, or 15 mg/m2) and nedaplatin (5 mg/m2, 10 mg/m2, or 15 mg/m2) twice-weekly based on the traditional 3 + 3 dose escalation strategy, and radiotherapy (64 Gy in 32 fractions). The primary goals were to determine the MTD of concurrent chemotherapy and the dose limiting toxicities (DLTs). In-field objective response rate (ORR) was investigated. RESULTS: Fifteen patients had been recruited and analyzed. DLT involving persistent grade 3 esophagitis over 1 week was observed in all three patients (3/3) at dose level 3 (15 mg/m2), and two patients (2/6) experienced DLTs in the dose level 2 (10 mg/m2) due to esophageal fistula and persistent grade 3 esophagitis over 1 week, while one patient (1/6) treated at dose level 1 (5 mg/m2) exhibited DLT owing to Grade 3 increased liver enzymes, suggesting a MTD of 5 mg/m2. The in-filed ORR was both 100% in all patients and those receiving MTD. The 1-year loco-regional recurrence-free survival rate was 83.3%, 83.3% and 66.7% in dose level 1, 2, and 3, respectively. CONCLUSIONS: The MTD of twice-weekly docetaxel and nedaplatin regimen was 5 mg/m2 in inoperable ESCC patients treated with definitive CCRT. Low dose concurrent docetaxel and nedaplatin showed promising radiosensitizing effect on in-filed disease control and good tolerability.

[Effects of Prostaglandin E2 Receptor 4 Agonist on the Expression of Stem Factors in Human CD34+ Cells].

OBJECTIVE: To investigate the effect of prostaglandin E2 recoptor 4 antagonist (EP4A) on the self-renewal ability of human CD34+ cells and its mechamism. METHODS: The peripheral blood hematopoietic stem cell of 20 healthy donors received the G-CSF-mobilization were collected, then the human CD34+ cells were sorted out by MACS microbead kit. The human CD34+ cells were treated with DMSO (control group), EP4A (EP4A group) and EP4A+EP4A antagonist (EP4A+EP4A group) for 72 hours. The differential genes and pathways related with CD34+ cell stemness were detected by Thermogram and Pathway enrichment analysis. and then the expression levels of protein and gene (ß-catenin, Nanog, Oct4, Sox2, Stat3, AKT, P38) were detected by qRT-PCR and Western blot respectively. RESULTS: EP4A could elevate the mRNA and protein expression of ß-catenin, Nanog, Oct4, Sox2, in comparison with control group, however, mRNA and protein expression of STAT3, AKT, P38 were not changed. When human CD34+ cell were cultured with EP4A+XAV939 it was found that the mRNA and protein expression of ß-catenin was downregulated, moreover the mRNA and protein expression of Nanog, Oct4, Sox2 were reduced. CONCLUSION: EP4A can upregulate stemness factors-ß-catenin, Nanog, Oct4 and Sox2 in human CD34+ cell in vitro, but not STAT3, AKT and P38.

Developing and validating an integrated gross tumor volume (GTV)-TNM stratification system for supplementing unresectable locally advanced non-small cell lung cancer treated with concurrent chemoradiotherapy.

PURPOSE: The gross tumor volume (GTV) could be an independent prognostic factor for unresectable locally advanced non-small cell lung cancer (LANSCLC). We aimed to develop and validate a novel integrated GTV-TNM stratification system to supplement LANSCLC sub-staging in patients treated with concurrent chemoradiotherapy (CCRT). METHODS: We performed a retrospective review of 340 patients with unresectable LANSCLC receiving definitive CCRT. All included patients were divided into two randomized cohorts. Then the Kaplan-Meier method and Cox regression were calculated to access the prognostic value of the integrated GTV-TNM stratification system, which was further validated by the area under the receiver operating characteristic curve (AUC) score and F1-score. RESULTS: The optimal outcome-based GTV cut-off values (70 and 180 cm3) of the modeling cohort were used to determine each patient's integrated GTV-TNM stratum in the whole cohort. Our results indicated that a lower integrated GTV-TNM stratum could had better overall survival and progression-free survival (all P < 0.001), which was recognized as an independent prognostic factor. Also, its prognostic value was robust in both the modeling and validation cohorts. Furthermore, the prognostic validity of the integrated GTV-TNM stratification system was validated by significantly improved AUC score (0.636 vs. 0.570, P = 0.027) and F1-score (0.655 vs. 0.615, P < 0.001), compared with TNM stage. CONCLUSIONS: We proposed a novel integrated GTV-TNM stratification system to supplement unresectable LANSCLC sub-staging due to its prognostic value independent of TNM stage and other clinical characteristics, suggesting that it could be considered in individual treatment decision-making process.

ARRB1-Promoted NOTCH1 Degradation Is Suppressed by OncomiR miR-223 in T-cell Acute Lymphoblastic Leukemia.

T-cell acute lymphoblastic leukemia (T-ALL) is a type of aggressive leukemia with inferior prognosis. Although activating mutations of NOTCH1 are observed in most T-ALL cases, these mutations alone are not sufficient to drive the full development of T-ALL. ß-Arrestins (ARRB) are versatile and multifunctional adapter proteins that regulate diverse cellular functions, including promoting the development of cancer. However, the role of ARRBs in T-ALL has largely remained elusive. In this study, we showed that ARRB1 is expressed at low levels in assayed T-ALL clinical samples and cell lines. Exogenous ARRB1 expression inhibited T-ALL proliferation and improved the survival of T-ALL xenograft animals. ARRB1 facilitated NOTCH1 ubiquitination and degradation through interactions with NOTCH1 and DTX1. Mechanistically, the oncogenic miRNA (oncomiR) miR-223 targets the 3'-UTR of ARRB1 (BUTR) and inhibits its expression in T-ALL. Furthermore, overexpression of the ARRB1-derived miR-223 sponge suppressed T-ALL cell proliferation and induced apoptosis. Collectively, these results demonstrate that ARRB1 acts as a tumor suppressor in T-ALL by promoting NOTCH1 degradation, which is inhibited by elevated miR-223, suggesting that ARRB1 may serve as a valid drug target in the development of novel T-ALL therapeutics.Significance: These findings highlight a novel tumor suppressive function of the adaptor protein ß-arrestin1 in T-ALL.

[Solubilizing and sustained-releasing abilities and safety preliminary evaluation for paclitaxel based on N-octyl-O, N-carboxymethyl chitosan polymeric micelles].

A series of novel self-assembled polymeric micelles based on carboxymethyl chitosan bearing long chain alkyl chains (N-octyl-O, N-carboxymethyl chitosan, OCC) was synthesized. PTX loaded OCC polymeric micelles (PTX-OCC) were prepared by dialysis method. The effects of the degree of substitutions (DS) of octyl groups on the solubilizing abilities of OCC for paclitaxel were studied. The PTX-OCC were characterized using drug loading content, drug encapsulation efficiency, dynamic light scattering, zeta potential and transmission electron microscopy (TEM). Take PTX injection (PTX-INJ) as control, the safety of PTX-OCC including hemolysis, hypersensitiveness in guinea pigs and acute toxicity in mice were also evaluated. OCC showed excellent loading capacities for paclitaxel with the DS of octyl groups in the range of 37.9% - 58.6%. Drug loading contents were up to 24.9% - 34.4% with drug encapsulation efficiency 56.3% - 89.3%, which both increased with the increasing of DS of octyl groups. The mean size of PTX-OCC was 186.4 - 201.1 nm which decreased with the increasing of DS of octyl groups. The zeta potential was -47.5 to -50.9 mV, which had no obvious relation with the DS of octyl groups. The TEM images showed a spherical shape. No burst release phenomena were observed and drug cumulative release was in the range of 60% -95% in 15 days. PTX-OCC with higher DS of octyl groups showed stronger sustained releasing ability. In terms of the induction of membrane damage and hypersensitiveness, PTX-OCC was superior to PTX-INJ. The LD50 and its 95% confidence interval of PTX-OCC were 134.4 (125.0 - 144.6) mg x kg(-1), which was 2.7 fold of PTX-INJ. The present PTX-OCC could be potentially useful as safety carriers for intravenous delivery.

The extracellular domain of Staphylococcus aureus LtaS binds insulin and induces insulin resistance during infection.

Insulin resistance is a risk factor for obesity and diabetes and predisposes individuals to Staphylococcus aureus colonization; however, the contribution of S. aureus to insulin resistance remains unclear. Here, we show that S. aureus infection causes impaired glucose tolerance via secretion of an insulin-binding protein extracellular domain of LtaS, eLtaS, which blocks insulin-mediated glucose uptake. Notably, eLtaS transgenic mice (eLtaS trans ) exhibited a metabolic syndrome similar to that observed in patients, including increased food and water consumption, impaired glucose tolerance and decreased hepatic glycogen synthesis. Furthermore, transgenic mice showed significant metabolic differences compared to their wild-type counterparts, particularly for the early insulin resistance marker α-hydroxybutyrate. We subsequently developed a full human monoclonal antibody against eLtaS that blocked the interaction between eLtaS and insulin, which effectively restored glucose tolerance in eLtaS trans and S. aureus-challenged mice. Thus, our results reveal a mechanism for S. aureus-induced insulin resistance.

[Prostaglandin E2 Receptor 4 Agonist Promotes Human CD34+ Cell Proliferation in vitro by Activating Wnt/ß-Catenin Signaling Pathway].

OBJECTIVE: To investigate the potential signaling pathway that regulates the proliferation of human CD34+ cells stimulated by prostaglandin E2 receptor 4 agonist (EP4A) in vitro. METHODS: Twenty samples of peripheral blood containing stem cells were collected from the G-CSF mobilized healthy donors in our department of hematology. Human CD34+ cells were isolated by magnetic activated cell sorting (MACS) microbeads kit. The Cell Counting Kit-8 (CCK8) assay was used to determine the optimal concentration and time of EP4A to promote human CD34+ cell proliferation in vitro. Under the optimal condition, quantitative real-time polymerase chain reaction (qRT-PCR) was used to detect mRNA level of ß-catenin, and Western blot was used to assay protein expression of ß-catenin and P-GSK-3ß in human CD34+ cells treated with EP4A. RESULTS: Culturing with 10 µmol/L EP4A for 72 h, it was found that EP4A promoted human CD34+ cell proliferation significantly, and the proliferation rate of human CD34+ cells was 1.36 times higher than that of the control(P=0.002). Under the optimal condition, it was also found that EP4A enhanced the ß-catenin expression at both mRNA and protein levels, and up-regulated phosphorylation of GSK-3ß in human CD34+ cells, but these effects could be inhibited by the EP4A antagonist EP4AA. CONCLUSION: EP4A can enhance human CD34+ cell proliferation in vitro by activating Wnt/ß-catenin signaling pathway.

microRNA-221 Enhances MYCN via Targeting Nemo-like Kinase and Functions as an Oncogene Related to Poor Prognosis in Neuroblastoma.

Purpose:MYCN is one of the most well-characterized genetic markers of neuroblastoma. However, the mechanisms as to how MYCN mediate neuroblastoma tumorigenesis are not fully clear. Increasing evidence has confirmed that the dysregulation of miRNAs is involved in MYCN-mediated neuroblastoma tumorigenesis, supporting their potential as therapeutic targets for neuroblastoma. Although miR-221 has been reported as one of the upregulated miRNAs, the interplay between miR-221 and MYCN-mediated neuroblastoma progression remains largely elusive.Experimental Design: The expression of miR-221 in the formalin-fixed, paraffin-embedded tissues from 31 confirmed patients with neuroblastoma was detected by locked nucleic acid-in situ hybridization and qRT-PCR. The correlation between miR-221 expression and clinical features in patients with neuroblastoma was assessed. The mechanisms as to how miR-221 regulate MYCN in neuroblastoma were addressed. The effect of miR-221 on cellular proliferation in neuroblastoma was determined both in vitro and in vivoResults: miR-221 was significantly upregulated in neuroblastoma tumor cells and tissues that overexpress MYCN, and high expression of miR-221 was positively associated with poor survival in patients with neuroblastoma. Nemo-like kinase (NLK) as a direct target of miR-221 in neuroblastoma was verified. In addition, overexpression of miR-221 decreased LEF1 phosphorylation but increased the expression of MYCN via targeting of NLK and further regulated cell cycle, particularly in S-phase, promoting the growth of neuroblastoma cells.Conclusions: This study provides a novel insight for miR-221 in the control of neuroblastoma cell proliferation and tumorigenesis, suggesting potentials of miR-221 as a prognosis marker and therapeutic target for patients with MYCN overexpressing neuroblastoma. Clin Cancer Res; 23(11); 2905-18. ©2016 AACR.