Nucleoside triphosphates (NTPs) play important roles in living organisms. However, no fluorescent assays are currently available to simply and rapidly detect multiple NTPs with satisfactory selectivity, sensitivity and low cost. Here we demonstrate for the first time a target-triggered in-vitro transcription machinery for ultra-selective, sensitive and instant fluorescence detection of multiple NTPs. The machinery assembles RNA polymerase, DNA template and non-target NTPs to convert the target NTP into equivalent RNA signal sequences which are monitored by the fluorescence enhancement of molecular beacon. The machinery offers excellent selectivity for the target NTP against NDP, NMP and dNTP. Notably, to accelerate the kinetics of the machinery while maintain its high specificity, we investigated the sequence of DNA templates systematically and established a set of guidelines for the design of the optimum DNA templates, which allowed for instant detection of the target NTP at fmol level in less than 1min. Furthermore, the machinery could be transformed into logic gates to study the coeffects of two NTPs in biosynthesis and real-time monitoring systems to reflect the distribution of NTP in nucleotide pools. These results provide very useful and low-cost tools for both biochemical tests and point-of-care analysis.
OBJECTIVE To study the effects of single nucleotide polymorphisms (SNP) in Plasminogen activator inhibitor 1(PAI-1) on breast cancer susceptibility and patients' prognosis among a Chinese Han women population. METHODS Six tag SNP (tSNP) of PAI-1 were selected according to HapMap CHB population, and TaqMan realtime PCR method was used to genotype the 6 tSNP in 1 160 breast cancer cases and 1 318 age-matched controls among Chinese Han women. Haplotypes and diplotypes were inferred according to genotyping data and linkage disequilibrium. Finally, the associations of tSNP, haplotypes and dipltypes with breast cancer susceptibility and patients' prognosis were analyzed. RESULTS Regarding to breast cancer susceptibility, for rs6090 (G>A), AA genotype carriers had 3.79 times higher risk of developing breast cancer (OR=4.79, 95%CI=1.01-22.64, P=0.048 0) than GG or GA genotype carriers. For rs2227672 (G>T), TT genotype carriers had 1.52 times higher breast cancer risk than GG or GT genotype carriers (OR=2.52, 95%CI=1.26-5.01, P=0.008 6). Regarding to breast cancer prognosis, women who carried rs2227692 (C>T) CT genotype had 46% lower risk of developing recurrence, metastasis or death than CC genotype carriers (HR=0.54, 95%CI=0.30-0.97, P=0.040 4). Using stratified association analysis, among BMI<23 patients, those women who carried AA genotype of rs2227631 (G>A) had 3.99 times higher risk of developing the events (recurrence, metastasis or death) than GG or GA genotype carriers (HR=4.99, 95%CI=1.66-15.02, P=0.004 2). Among HER2 positive patients, those women who carried AA genotype of rs2227667 (G>A) had 2.98 times higher risk of developing the events (recurrence, metastasis or death) than GG or GA genotype carriers (HR=3.98, 95%CI=1.47-10.80, P=0.006 7). Among patients with tumors>2 cm, those women who carried rs2227692 (C>T) CT or TT genotype had 51% lower risk of developing the events (recurrence, metastasis or death) than CC genotype carriers (HR=0.49, 95%CI=0.27-0.88, P=0.017 0). CONCLUSIONS The study indicates that single nucleotide polymorphisms in PAI-1 may affect breast cancer susceptibility and survival in Chinese Han women. The study may contribute to individualized evaluation of breast cancer risk and patients' prognosis if these data are validated in some other Chinese Han populations.
An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
The epidermal growth factor receptor (EGFR) has an essential role in multiple signaling pathways, including cell proliferation and migration, through extracellular ligand binding and subsequent activation of its intracellular tyrosine kinase (TK) domain. The non-small cell lung cancer (NSCLC)-associated EGFR mutants, L858R and G719S, are constitutively active and oncogenic. They display sensitivity to TK inhibitors, including gefitinib and erlotinib. In contrast, the secondary mutation of the gatekeeper residue, T790M, reportedly confers inhibitor resistance on the oncogenic EGFR mutants. In this study, our biochemical analyses revealed that the introduction of the T790M mutation confers gefitinib resistance on the G719S mutant. The G719S/T790M double mutant has enhanced activity and retains high gefitinib-binding affinity. The T790M mutation increases the ATP affinity of the G719S mutant, explaining the acquired drug resistance of the double mutant. Structural analyses of the G719S/T790M double mutant, as well as the wild type and the G719S and L858R mutants, revealed that the T790M mutation stabilizes the hydrophobic spine of the active EGFR-TK conformation. The Met790 side chain of the G719S/T790M double mutant, in the apo form and gefitinib- and AMPPNP-bound forms, adopts different conformations that explain the accommodation of these ligands. In the L858R mutant structure, the active-site cleft is expanded by the repositioning of Phe723 within the P-loop. Notably, the introduction of the F723A mutation greatly enhanced the gefitinib sensitivity of the wild-type EGFR in vivo, supporting our hypothesis that the expansion of the active-site cleft results in enhanced gefitinib sensitivity. Taken together, our results provide a structural basis for the altered drug sensitivities caused by distinct NSCLC-associated EGFR mutations. Oncogene (2013) 32, 27-38; doi:10.1038/onc.2012.21; published online 20 February 2012
We report here the identification and characterization of a protein, ERIS, an endoplasmic reticulum (ER) IFN stimulator, which is a strong type I IFN stimulator and plays a pivotal role in response to both non–self-cytosolic RNA and dsDNA. ERIS (also known as STING or MITA) resided exclusively on ER membrane. The ER retention/retrieval sequence RIR was found to be critical to retain the protein on ER membrane and to maintain its integrity. ERIS was dimerized on innate immune challenges. Coumermycin-induced ERIS dimerization led to strong and fast IFN induction, suggesting that dimerization of ERIS was critical for self-activation and subsequent downstream signaling.