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Genes of human mitochondrial tRNALeu(UUR) (mtRNALeu(UUR)) and its mutant (mtRNALeu(M)) were synthesized and inserted into the plasmid pGEM-9Zf(-) respectively. E.coli JM 109 was transformed by the recombinant plasmids containing the target genes. The mtRNALeu(UUR) and mtRNALeu(M) were expressed up to 19.10% and 17.76% of total small RNA respectively. They were purified to 54% homogeneity by DEAE-sepharose-CL4B column chromatography and finally repurified by 15% PAGE/urea. Their kinetic parameters for E.coli LeuRS were measured. The results showed that the value of kcal/ Km of mtRNALeu(M) was about one fifth of that of mtRNALeu(UUR) and indicated the leucine acceptability of mtRNALeu(M) was much lower than that of mtRNALeu(UUR). [ABSTRACT FROM AUTHOR]

The development of high‐performance blue organic light‐emitting diodes (OLEDs) remains a challenging task. While exploiting new blue emitters has attracted great interest, developing host materials that considerably determine device performance obviously lags behind. Herein, we present an ease of access to the structurally diverse benzoheteroaromatic‐fused pyridine skeletons by the iridium‐catalyzed intramolecular C−H/C−H coupling reaction, which unlocks an unparalleled opportunity to rapidly assemble a library of pyridine‐fused bipolar host materials. As an illustrated example, the benzo[4,5]thieno[2,3‐b]pyridine skeleton (BTP) has been made to a pseudo‐symmetric host (DCz‐BTP). The merging of a pyridine fragment enables strong intermolecular interactions, leading to satisfactory bipolar transporting properties. Utilizing DCz‐BTP as the host, blue thermally activated delayed fluorescent OLEDs (TADF‐OLEDs) exhibit a low turn‐on voltage of 2.8 V and a high maximum external quantum efficiency (EQEmax) of 29.0 % and blue TADF‐sensitized florescent OLEDs (TSF‐OLEDs) give an EQEmax as high as 20.5 %, revealing the potential of the BTP skeleton for the construction of high‐performance host materials. [ABSTRACT FROM AUTHOR]

Background: Occurrence of squamous cell carcinoma (SCC) even in early-stage, untreated chronic lymphocytic leukemia (CLL) patients can be a significant morbidity issue with occasional transformation into metastatic skin lesions. Methods: CLL cells and extracellular vesicles (EVs) from CLL patients' blood/plasma were purified and used. Expression/activation of AXL and its functions in normal keratinocytes (HEKa) were assessed in vitro co-culture system and in SCC tissues. Results: We detected aberrant activation of AXL, AKT and ERK-1/2 in SCC cell lines compared to HEKa. We also detected increased expression of AXL in primary SCC tissues obtained from CLL patients. Increased activation of AXL, AKT, ERK-1/2 and Src was discernible in HEKa upon co-culturing with CLL cells. Further analysis suggests that Gas6, a ligand of AXL, regulates AXL activation in co-cultured HEKa. Interestingly, exposure of HEKa cells to CLL plasma-derived EVs induced expression of AXL, P-AKT, and EMT-associated markers leading to migration of the cells. Finally, pharmacologic inhibition of AXL induced cell death in SCC lines in a dose dependent manner. Conclusions: Our findings that CLL cells likely are involved in driving SCC progression, at least in part, via activation of the AXL signaling axis, indicating that AXL inhibition may be beneficial for our CLL patients with SCC. [ABSTRACT FROM AUTHOR]

Double/triple-hit lymphomas (DHL/THL) account for 5–10% of diffuse large B cell lymphoma (DLBCL) with rearrangement of MYC and BCL2 and/or BCL6 resulting in MYC overexpression. Despite the poor prognosis of DHL, R-CHOP chemotherapy remains the treatment backbone and new targeted therapy is needed. We performed comprehensive cytogenetic studies/fluorescence in situ hybridization on DLBCL and Burkitt lymphoma cell lines (n = 11) to identify the DHL/THL DLBCL in vitro model. We identified MYC/IG in Raji and Ramos (single hit); MYC/IG-BCL2 (DHL) in DOHH2, OCI-LY1, SUDHL2, and OCI-LY10; MYC/IG-BCL2/BCL6 (THL) in VAL; and no MYC rearrangement in U2932 and HBL1 (WT-MYC). Targeting MYC in the DHL/THL DLBCLs through bromodomain extra-terminal inhibitors (BETi) (JQ1, I-BET, and OTX015) significantly (p < 0.05) reduced proliferation, similar to WT-MYC cells, accompanied by decreased MYC but not BCL2 protein. Moreover, BETi suppressed MYC transcription and decreased BRD4 binding to MYC promoter in DHL cells. CD47 and PD-L1 are immunoregulatory molecules often expressed on tumors and regulated by MYC. High levels of surface CD47 but not surface PD-L1 was observed in DHL/THL, which was reduced by JQ1 treatment. BETi in combination with Pan-HDAC inhibitor had a limited effect on survival of DHL/THL, while combination of BETi and BCL2 inhibitor (ABT-199) had a significant (p < 0.005) inhibitory effect on survival followed by BCL-XL inhibition. Overall, the data suggests that MYC-expressing DLBCLs are probably addicted to the MYC-oncogenic effect regardless of MYC rearrangements. In summary, we identified an in vitro model for DHL/THL DLBCLs and provide evidence for the therapeutic potential of BET inhibitor alone or in combination with BCL2 inhibitor. [ABSTRACT FROM AUTHOR]

[Display omitted] • A new type acceptor with fused pyrazine and maleimide is developed. • A "locked" biphenyl bridge is designed to reduce ΔE ST and boost Φ PL. • An EQE max of 26.0% with a low efficiency roll off is realized for orange – red OLEDs. The strategy to develop orange – red thermally activated delayed fluorescent (TADF) materials for high-performance organic light-emitting diodes (OLEDs) with both high maximum external quantum efficiencies (EQEs max) and low efficiency roll-off, is ongoing pursued yet challenging. Herein, two efficient orange – red TADF emitters, T -DMAC-PPyM and P -DMAC-BPyM, with a new acceptor fused by pyrazine and maleimide, were designed and synthesized. Notably, the highly twisted conformation of P -DMAC-BPyM can inhibit the close π-π stacking, so as to reduce exciton quenching, while the "locked" biphenyl bridge can enhance the molecular rigidity, thus reducing the non-radiative decay associated with intramolecular rotation. Consequently, P -DMAC-BPyM exhibits outstanding electroluminescent performance with a remarkably high EQE max of 26.0% and an impressively low efficiency roll-off (EQE 100 is 21.7%; EQE 1000 is 18.3%), which are among the best results for orange – red TADF OLEDs. [ABSTRACT FROM AUTHOR]

Abstract: Background: Glutathione S-transferase (GST) P1 is a major phase II xenobiotic-metabolizing enzyme in the human lung. Our laboratory had previously identified nine single nucleotide polymorphisms (SNPs) in the GSTP1 gene promoter, which were then grouped into three main haplotypes (Hap1, Hap2, and Hap3) based on statistical inference. Hap3 was found to display a high expression phenotype. The main objective of the current study was to test the association between GSTP1 promoter haplotypes with the risk of lung cancer after determining the promoter haplotypes experimentally through cloning and sequencing. Methods: We conducted a case–control analysis of 150 subjects with lung cancer and 329 controls with no personal history of the disease. The three statistically inferred GSTP1 promoter haplotypes were confirmed experimentally through cloning and sequencing. Haplotype-tagging SNPs were selected and GSTP1 haplotypes were tested for genetic association to lung cancer using unconditional logistic regression after adjusting for confounders. Statistical interaction between GSTP1 promoter haplotypes with either cigarette smoking or dietary fruit and vegetable intake were tested using the likelihood ratio test. Results: We did not find protective effects of Hap3 against lung cancer, despite an adequately powered design for this main effect. Homozygous variants of tagSNPs −1738 T>A and −354 G>T, which tag Hap2, showed an increased (but statistically non-significant) risk of lung cancer among all subjects as well as among individuals with low fruit and vegetable intake, compared to homozygous wildtypes for these SNPs. We did not find significant interactions between Hap2 and dietary intake of fruits and vegetables. Conclusions: Our results do not support significant main and modifying effects for GSTP1 promoter haplotypes on susceptibility to lung cancer in this population, but reinforce the protective effects of dietary intake of fruits and vegetables. [Copyright &y& Elsevier]

A promising type of electron transport material based on phenanthroline framework is designed, which shows a large electron mobility, a high thermal stability and a strong n-doping ability with air-stable transitional metal of Ag, and is used as multifunctional material in OLEDs to improve the efficiency and enhance the stability. 4,7-Bisphenyl-1,10-phenanthroline (BPhen) is a promising electron transport material (ETM) and has been widely used in organic light-emitting diodes (OLEDs) because of the large electron mobility and easy fabrication process. However, its low glass transition temperature would lead to poor device stability. In the past decades, various attempts have been carried out to improve its thermal stability though always be accomplished by the reduced electron mobility. Here, we present a molecular engineering to modulate the properties of BPhen, and through which, a versatile BPhen derivative (4,7-bis(naphthalene-β-yl)-1,10-phenanthroline, β-BNPhen) with high thermal stability (glass transition temperature = 111.9 °C), large electron mobility (7.8 × 10−4 cm2/(V s) under an electrical field of 4.5 × 105 V/cm) and excellent n-doping ability with an air-stable metal of Ag is developed and used as multifunctional layers to improve the efficiency and enhance the stability of OLEDs. This work elucidates the great importance of our molecular engineering methodology and device structure optimization strategy, unlocking the potential of 1,10-phenanthroline derivatives towards practical applications. [ABSTRACT FROM AUTHOR]

Ig secretion by terminally differentiated B cells is an important component of the immune response to foreign pathogens. Its overproduction is a defining characteristic of several B cell malignancies, including Waldenström macroglobulinemia (WM), where elevated IgM is associated with significant morbidity and poor prognosis. Therefore, the identification and characterization of the mechanisms controlling Ig secretion are of great importance for the development of future therapeutic approaches for this disease. In this study, we define a novel pathway involving the oncogenic transcription factor GLI2 modulating IgM secretion by WM malignant cells. Pharmacological and genetic inhibition of GLI2 in WM malignant cells resulted in a reduction in IgM secretion. Screening for a mechanism identified the IL-6Ra (gp80) subunit as a downstream target of GLI2 mediating the regulation of IgM secretion. Using a combination of expression, luciferase, and chromatin immunoprecipitation assays we demonstrate that GLI2 binds to the IL-6Ra promoter and regulates its activity as well as the expression of this receptor. Additionally, we were able to rescue the reduction in IgM secretion in the GLI2 knockdown group by overexpressing IL-6Ra, thus defining the functional significance of this receptor in GLI2-mediated regulation of IgM secretion. Interestingly, this occurred independent of Hedgehog signaling, a known regulator of GLI2, as manipulation of Hedgehog had no effect on IgM secretion. Given the poor prognosis associated with elevated IgM in WM patients, components of this new signaling axis could be important therapeutic targets. [ABSTRACT FROM AUTHOR]

Polychlorinated biphenyls (PCBs), such as 2,2',3,5',6-pentachlorobiphenyl (PCB95), are persistent organic pollutants associated with adverse health outcomes, including developmental neurotoxicity. PCB95 is a chiral neurotoxic PCB congener atropselectively metabolized to potentially neurotoxic metabolites in vivo. However, the metabolic pathways of most PCB congeners, including PCB95, remain unknown. To address this knowledge gap, we analyzed the intestinal contents of mice exposed to PCB95 to elucidate the PCB95 metabolism pathway and assess if genetic manipulation of hepatic drug-metabolizing enzymes affects PCB95 metabolism. Our study exposed male and female wildtype (WT), Cyp2abfgs -null (KO), and CYP2A6-transgenic/ Cyp2abfgs-null (KI) mice orally to 1.0 mg/kg body weight of PCB95. Intestinal content was collected 24 h after PCB administration. aS-PCB95 was enriched in all intestinal content samples, irrespective of sex and genotype. Gas chromatography-tandem mass spectrometry (GC-MS/MS) analyses identified 5 mono- (OH-PCB95) and 4 dihydroxylated PCB (diOH-PCB95) metabolites. Liquid chromatography-high-resolution mass spectrometry (LC-HRMS) identified 15 polar hydroxylated, methoxylated, and sulfated PCB95 metabolites, including 3 dechlorinated metabolites. A sex difference in the relative OH-PCB95 levels was observed only for KO in the LC-HRMS analysis. Genotype-dependent differences were observed for female, but not male, mice, with OH-PCB95 levels in female KO (F KO ) mice tending to be lower than those in female WT (F WT ) and KI (F KI ) mice. Based on the GC-MS/MS analysis, these differences are due to the unknown PCB95 metabolites, X1-95 and Y1-95. These findings demonstrate that combining GC-MS/MS analyses and LC-HRMS subject screening of the intestinal content of PCB95-exposed mice can significantly advance our understanding of PCB95 metabolism in vivo.