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Ultrasensitive Nanopore Sensing of Mucin 1 and Circulating Tumor Cells in Whole Blood of Breast Cancer Patients by Analyte-Triggered Triplex-DNA Release.
Sun, K, Chen, P, Yan, S, Yuan, W, Wang, Y, Li, X, Dou, L, Zhao, C, Zhang, J, Wang, Q, et al
ACS applied materials & interfaces. 2021;(18):21030-21039
Abstract
The characterization of circulating tumor cells (CTCs) by liquid biopsy has a great potential for precision medicine in oncology. Here, a universal and tandem logic-based strategy is developed by combining multiple nanomaterials and nanopore sensing for the determination of mucin 1 protein (MUC1) and breast cancer CTCs in real samples. The strategy consists of analyte-triggered signal conversion, cascaded amplification via nanomaterials including copper sulfide nanoparticles (CuS NPs), silver nanoparticles (Ag NPs), and biomaterials including DNA hydrogel and DNAzyme, and single-molecule-level detection by nanopore sensing. The amplification of the non-DNA nanomaterial gives this method considerable stability, significantly lowers the limit of detection (LOD), and enhances the anti-interference performance for complicated samples. As a result, the ultrasensitive detection of MUC1 could be achieved in the range of 0.0005-0.5 pg/mL, with an LOD of 0.1 fg/mL. Moreover, we further tested MUC1 as a biomarker for the clinical diagnosis of breast cancer CTCs under double-blind conditions on the basis of this strategy, and MCF-7 cells could be accurately detected in the range from 5 to 2000 cells/mL, with an LOD of 2 cells/mL within 6 h. The detection results of the 19 clinical samples were highly consistent with those of the clinical pathological sections, nuclear magnetic resonance imaging, and color ultrasound. These results demonstrate the validity and reliability of our method and further proved the feasibility of MUC1 as a clinical diagnostic biomarker for CTCs.
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2.
Single molecule detection of nitric oxide enabled by d(AT)15 DNA adsorbed to near infrared fluorescent single-walled carbon nanotubes.
Zhang, J, Boghossian, AA, Barone, PW, Rwei, A, Kim, JH, Lin, D, Heller, DA, Hilmer, AJ, Nair, N, Reuel, NF, et al
Journal of the American Chemical Society. 2011;(3):567-81
Abstract
We report the selective detection of single nitric oxide (NO) molecules using a specific DNA sequence of d(AT)(15) oligonucleotides, adsorbed to an array of near-infrared fluorescent semiconducting single-walled carbon nanotubes (AT(15)-SWNT). While SWNT suspended with eight other variant DNA sequences show fluorescence quenching or enhancement from analytes such as dopamine, NADH, L-ascorbic acid, and riboflavin, d(AT)(15) imparts SWNT with a distinct selectivity toward NO. In contrast, the electrostatically neutral polyvinyl alcohol enables no response to nitric oxide, but exhibits fluorescent enhancement to other molecules in the tested library. For AT(15)-SWNT, a stepwise fluorescence decrease is observed when the nanotubes are exposed to NO, reporting the dynamics of single-molecule NO adsorption via SWNT exciton quenching. We describe these quenching traces using a birth-and-death Markov model, and the maximum likelihood estimator of adsorption and desorption rates of NO is derived. Applying the method to simulated traces indicates that the resulting error in the estimated rate constants is less than 5% under our experimental conditions, allowing for calibration using a series of NO concentrations. As expected, the adsorption rate is found to be linearly proportional to NO concentration, and the intrinsic single-site NO adsorption rate constant is 0.001 s(-1) μM NO(-1). The ability to detect nitric oxide quantitatively at the single-molecule level may find applications in new cellular assays for the study of nitric oxide carcinogenesis and chemical signaling, as well as medical diagnostics for inflammation.
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3.
[Separation of proteins on microchip electrophoresis and its comparison with DNA migration].
Liu, C, Xu, X, Zhang, J, Chen, J
Se pu = Chinese journal of chromatography. 2010;(3):296-300
Abstract
The efficient separation of six standard proteins on a home-made poly (dimethylsiloxane) microchip with an auto-deducting background diode laser induced fluorescence detector was accomplished within 6.4 min under the sieving matrix of 10 g/L hydroxyethyl cellulose (HEC), 1 g/L sodium dodecyl sulphonate (SDS), 40 mmol/L phosphate buffer at pH 7.0. The experimental results showed that the reproducibility of protein separation was satisfactory and the relative standard deviations (RSDs) of protein migration time were less than 10%. The migration times of the proteins are analyzed by a quantitative mathematical model of deoxyribonucleic acid (DNA) proposed by ourselves previously. The results showed that the migration character of SDS-protein complexes was similar with DNA. However, the linear relationships between the mobilities of SDS-protein complexes and their relative molecular mass as well as electric field strength became worse, which indicated the mathematical model for DNA separation should be revised before it is used for protein separation.
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4.
Synthesis, cytotoxicity and DNA-binding levels of new type binuclear platinum(II) complexes.
Zhang, J, Li, Y, Sun, J, Li, W, Gong, Y, Zheng, X, Cui, J, Wang, R, Wu, J
European journal of medicinal chemistry. 2009;(11):4772-7
Abstract
Six new type binuclear platinum(II) complexes (a-f) have been synthesized and characterized by elemental analysis, conductivity, thermal analysis, IR, UV, (1)H NMR and mass spectra techniques. The cytotoxicity of the complexes was tested by MTT and SRB assays. The cell cycle analysis and the levels of total platinum bound to DNA were measured by flow cytometry and ICP-MS, respectively. The results indicate that the complex (a) has no cytotoxicity against HL-60, BGC-823, Bel-7402, KB and Hela, the complexes (b, c, e and f) have weaker cytotoxicity against some tested carcinoma cell lines, the complex (d) has better cytotoxicity against HL-60, BGC-823, Bel-7402, KB, MCF-7, HCT-8 and Hela with respect to the IC(50) values obtained. The cytotoxicity of the complex (d) is equal to that of cisplatin against HL-60 and Bel-7402 (P>0.05), but it has better cytotoxicity than that of cisplatin against BGC-823 and MCF-7 (P<0.05). The complex (d) causes significant G(2)/M arrest and a concomitant decrease of cell population in G(1) and S phases, and the total DNA platination levels of the complex (d) are higher than those of cisplatin under the same experimental conditions. It suggests that the bridging linker has important effect on their cytotoxicity. Indeed, when the bridging linker is dicarboxylic acid, their cytotoxicity is better than that of platinum complexes with an amino acid as bridging linker. The new type binuclear platinum(II) complexes represent a novel class of anticancer agents, which deserves further attention in search of anticancer lead compounds.
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5.
Self-energy-limited ion transport in subnanometer channels.
Bonthuis, DJ, Zhang, J, Hornblower, B, Mathé, J, Shklovskii, BI, Meller, A
Physical review letters. 2006;(12):128104
Abstract
The current-voltage characteristics of the alpha-Hemolysin protein pore during the passage of single-stranded DNA under varying ionic strength C are studied experimentally. We observe strong blockage of the current, weak superlinear growth of the current as a function of voltage, and a minimum of the current as a function of C. These observations are interpreted as the result of the ion electrostatic self-energy barrier originating from the large difference in the dielectric constants of water and the lipid bilayer. The dependence of DNA capture rate on C also agrees with our model.
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6.
CREB DNA binding activation by a 50-Hz magnetic field in HL60 cells is dependent on extra- and intracellular Ca(2+) but not PKA, PKC, ERK, or p38 MAPK.
Zhou, J, Yao, G, Zhang, J, Chang, Z
Biochemical and biophysical research communications. 2002;(4):1013-8
Abstract
To investigate the possible mechanism of gene transcription changes induced by magnetic field (MF), we examined the DNA binding behavior of the transcription factor cyclic-AMP responsive element binding protein (CREB) in HL60 cells after exposure to a 0.1mT 50-Hz extremely low frequency (ELF) sinusoidal MF by a gel shift assay. Magnetic field induced a time-dependent activation of CREB binding. The complex formation increased shortly after MF exposure for 10min, reaching a peak level after 1h, and then recovered to basal level at 4h after exposure. A novel MF-induced ATF2/ATF2 homodimer formation was observed after MF exposure for 30min, 1, and 2h. Furthermore, We found that the MF-induced increase of CREB DNA binding in HL60 cells was dependent on both extracellular and intracellular Ca(2+) but not PKA, PKC, ERK, or p38 MAPK by using various pathway inhibitors. These data indicate that MF exposure activates CREB DNA binding through calcium-related signal transduction pathways under our experimental conditions.