A G‐Quadruplex Aptamer Inhibits the Phosphatase Activity of Oncogenic Protein Shp2 in vitro

Hu, Jia; Wu, Jie; Liu, Cong; Zhu, Ling; Zhang, Wei Yun; Kong, Guiping; Lu, Zhongxian; Yang, Chaoyong

doi:10.1002/cbic.201000470

Cited by 38 publications

(32 citation statements)

References 56 publications

(41 reference statements)

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“…The observed stronger adhesion between the probe and the substrate in the presence of 60 mM K + is further confirmed by our CD measurement. 51 Notably, for HJ24 in the absence of K + , peak I at 16.9 pN and peak II at 39.0 pN, Figure 5b, are close to that of control DNA at 27.5 pN and HJ24 in the presence of K + at 49.7 pN, respectively, although both are shifted toward lower values. The peak area ratio for peak I and II is 1:3.…”

Section: ■ Experimentssupporting

confidence: 56%

Single-Molecule Force Spectroscopic Studies on Intra- and Intermolecular Interactions of G-Quadruplex Aptamer with Target Shp2 Protein

Zhao

Liang

et al. 2012

J. Phys. Chem. B

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With widespread applications in biosensors, diagnostics, and therapeutics, much investigation has been made in the structure of the G-quadruplexes and mechanism of their interactions with protein targets. However, in view of AFM based single-molecule force spectroscopic (SMFS) studies of G-quadruplex systems, only bimolecular approaches have been employed. In this article, we present an improved dual-labeling approach for surface immobilization of G-quadruplex DNA apatmers for investigation of intramolecular interaction from an integral unimolecular G-quadruplex system. The melting force of HJ24 G-quadruplex aptamer in the presence of K(+) has been successfully measured. It has been found that dynamic equilibrium exists between unfolding and folding structures of the HJ24 aptamer even in pure water. We also investigated the interactions between the HJ24 aptamer and its target protein (Shp2) under the same solution condition. The HJ24/Shp2 unbinding force in the absence of K(+), 42.0 pN, is about 50% smaller than that in the presence of K(+), 61.7 pN. The great reduction in force in the absence of K(+) suggests that the stability of G-quadruplex secondary structure is important for a stable HJ24/Shp2 binding. The methodology developed and demonstrated in this work is applicable for studying the stability of secondary structures of other unimolecular G-quadruplex aptamers and their interactions with target proteins.

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Section: ■ Experimentssupporting

confidence: 56%

Single-Molecule Force Spectroscopic Studies on Intra- and Intermolecular Interactions of G-Quadruplex Aptamer with Target Shp2 Protein

Zhao

Liang

et al. 2012

J. Phys. Chem. B

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“…In Figure 2a , we showed the most probable secondary structures of these aptamers, taking into account the lower free energy (ΔG). Because many of the aptamers described in the literature contain G-quadruplex structures, 22,23,24 which strongly stabilize the tertiary structure, the capacity of apMNK2F and apMNK3R to form G-quadruplex structures was studied using the QGRS Mapper program. The analysis results indicated that the aptamer apMNK2F could form two of these structures, one with three and one with two flat planes, while apMNK3R could form a two plane G-quadruplex structure ( Figure 2a ).…”

Section: Resultsmentioning

confidence: 99%

Characterization of MNK1b DNA Aptamers That Inhibit Proliferation in MDA-MB231 Breast Cancer Cells

García-Recio

Pinto-Díez

Pérez-Morgado

et al. 2016

Molecular Therapy - Nucleic Acids

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Elevated expression levels of eukaryotic initiation factor 4E (eIF4E) promote cancer development and progression. MAP kinase interacting kinases (MNKs) modulate the function of eIF4E through the phosphorylation that is necessary for oncogenic transformation. Therefore, pharmacologic MNK inhibitors may provide a nontoxic and effective anticancer strategy. MNK1b is a truncated isoform of MNK1a that is active in the absence of stimuli. Using in vitro selection, high-affinity DNA aptamers to MNK1b were selected from a library of ssDNA. Selection was monitored using the enzyme-linked oligonucleotide assay (ELONA), and the selected aptamer population was cloned and sequenced. Four groups of aptamers were identified, and the affinities of one representative for rMNK1b were determined using ELONA and quantitative polymerase chain reaction. Two aptamers, named apMNK2F and apMNK3R, had a lower Kd in the nmol/l range. The secondary structure of the selected aptamers was predicted using mFold, and the QGRS Mapper indicated the presence of potential G-quadruplex structures in both aptamers. The selected aptamers were highly specific against MNK1, showing higher affinity to MNK1b than to MNK1a. Interestingly, both aptamers were able to produce significant translation inhibition and prevent tumor cell proliferation and migration and colony formation in breast cancer cells. These results indicate that MNK1 aptamers have an attractive therapeutic potential.

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“…Aptamers must ideally have a high stability, important for applications in biological systems in order to reach their target proteins without being degraded. Many of the aptamers described in the literature contain G-quadruplex structures, [32][33][34] which strongly stabilize the tertiary structure. Interestingly, ApTLR#1RT exhibits relatively high free energy but, eventually, it would be able to form a G-quadruplex structure.…”

Section: Discussionmentioning

confidence: 99%

TLR4-Binding DNA Aptamers Show a Protective Effect against Acute Stroke in Animal Models

Fernández¹,

Moraga

Cuartero

et al. 2018

Molecular Therapy

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Since Toll-like receptor 4 (TLR4) mediates brain damage after stroke, development of TLR4 antagonists is a promising therapeutic strategy for this disease. Our aim was to generate TLR4-blocking DNA aptamers to be used for stroke treatment. From a random oligonucleotide pool, we identified two aptamers (ApTLR#1R, ApTLR#4F) with high affinity for human TLR4 by systematic evolution of ligands by exponential enrichment (SELEX). Optimized truncated forms (ApTLR#1RT, ApTLR#4FT) were obtained. Our data demonstrate specific binding of both aptamers to human TLR4 as well as a TLR4 antagonistic effect. ApTLR#4F and ApTLR#4FT showed a long-lasting protective effect against brain injury induced by middle cerebral artery occlusion (MCAO), an effect that was absent in TLR4-deficient mice. Similar effects were obtained in other MCAO models, including in rat. Additionally, efficacy of ApTLR#4FT in a model of brain ischemia-reperfusion in rat supports the use of this aptamer in patients undergoing artery recanalization induced by pharmacological or mechanical interventions. The absence of major toxicology aspects and the good safety profile of the aptamers further encourage their future clinical positioning for stroke therapy and possibly other diseases in which TLR4 plays a deleterious role.

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A G‐Quadruplex Aptamer Inhibits the Phosphatase Activity of Oncogenic Protein Shp2 in vitro

Cited by 38 publications

References 56 publications

Single-Molecule Force Spectroscopic Studies on Intra- and Intermolecular Interactions of G-Quadruplex Aptamer with Target Shp2 Protein

Single-Molecule Force Spectroscopic Studies on Intra- and Intermolecular Interactions of G-Quadruplex Aptamer with Target Shp2 Protein

Characterization of MNK1b DNA Aptamers That Inhibit Proliferation in MDA-MB231 Breast Cancer Cells

TLR4-Binding DNA Aptamers Show a Protective Effect against Acute Stroke in Animal Models

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