22 research outputs found
Discovery of 2âAcylaminothiophene-3-Carboxamides as Multitarget Inhibitors for BCR-ABL Kinase and Microtubules
The
emergence of drug resistance of the BCR-ABL kinase inhibitor
imatinib, especially toward the T315I gatekeeper mutation, poses a
great challenge to targeted therapy in treating chronic myeloid leukemia
(CML) patients. To discover novel inhibitors against drug-resistant
CML bearing T315I mutation, we applied a physics-based hierarchical
virtual screening approach to dock a large chemical library against
ATP binding pockets of both wild-type (WT) and T315I mutant ABL kinases
in a combinatorial fashion. This strategy automatically resulted in
87 compounds satisfying structural and energetic criteria of both
WT and T315I mutant kinases. Among them, nine compounds, which share
a common thiophene-based scaffold and adopt similar binding poses,
were chosen for experimental testing and one of them was shown to
have low micromolar inhibition activities against both WT and mutant
ABL kinases. Structureâactivity relationship analysis with
a series of structural modifications based on 2-acylaminothiophene-3-carboxamide
scaffold supports our predicted binding mode. Interestingly, the same
chemical scaffold was also enriched in our previous virtual screening
campaign against colchicine site of microtubules using the same computational
protocol, which suggests our virtual screening strategy is capable
of discovering small-molecule ligands targeting distinct protein binding
sites without sharing any sequential and structural similarity. Furthermore,
the multitarget inhibition activity of this class of compounds was
assessed in cellular experiments. We expect that the 2-acylaminothiophene-3-carboxamide
scaffold may serve as a promising starting point for developing multitarget
inhibitors in cancer treatment by targeting both kinases and microtubules
Evaluation and Application of MD-PB/SA in Structure-Based Hierarchical Virtual Screening
Molecular
dynamics (MD) based molecular mechanics PoissonâBoltzmann
and surface area (MM-PB/SA) calculation (MD-PB/SA) has been widely
used to estimate binding free energies for receptorâligand
complexes. While numerous reports have focused on assessing accuracy
and efficiency, fewer studies have paid attention to performance in
lead discovery. In the present study, we report a critical evaluation
of MD-PB/SA in hierarchical virtual screening (HVS) both theoretically
and practically. It is shown that based on native poses, MD-PB/SA
could be well applied to predict the relative binding energy for both
congeneric and diverse ligands for different protein targets. However,
there is a limitation for MD-PB/SA to distinguish the native pose
of one ligand from the artificial pose of another when a huge difference
exists between two molecules. By combining a physics-based scoring
function with a knowledge-based structural filter, we improve the
predictability and validate the practical use of MD-PB/SA in lead
discovery by identifying novel inhibitors of p38 MAP kinase. We also
expand our study to other protein targets such as HIV-1 RT and NA
to assess the general validity of MD-PB/SA
Table_3_Comprehensive analysis of prediction of the EGFR mutation and subtypes based on the spinal metastasis from primary lung adenocarcinoma.docx
PurposeTo investigate the use of multiparameter MRI-based radiomics in the in-depth prediction of epidermal growth factor receptor (EGFR) mutation and subtypes based on the spinal metastasis in patients with primary lung adenocarcinoma.MethodsA primary cohort was conducted with 257 patients who pathologically confirmed spinal bone metastasis from the first center between Feb. 2016 and Oct. 2020. An external cohort was developed with 42 patients from the second center between Apr. 2017 and Jun. 2021. All patients underwent sagittal T1-weighted imaging (T1W) and sagittal fat-suppressed T2-weight imaging (T2FS) MRI imaging. Radiomics features were extracted and selected to build radiomics signatures (RSs). Machine learning classify with 5-fold cross-validation were used to establish radiomics models for predicting the EGFR mutation and subtypes. Clinical characteristics were analyzed with Mann-Whitney U and Chi-Square tests to identify the most important factors. Nomogram models were developed integrating the RSs and important clinical factors.ResultsThe RSs derived from T1W showed better performance for predicting the EGFR mutation and subtypes compared with those from T2FS in terms of AUC, accuracy and specificity. The nomogram models integrating RSs from combination of the two MRI sequences and important clinical factors achieved the best prediction capabilities in the training (AUCs, EGFR vs. Exon 19 vs. Exon 21, 0.829 vs. 0.885 vs.0.919), internal validation (AUCs, EGFR vs. Exon 19 vs. Exon 21, 0.760 vs. 0.777 vs.0.811), external validation (AUCs, EGFR vs. Exon 19 vs. Exon 21, 0.780 vs. 0.846 vs.0.818). DCA curves indicated potential clinical values of the radiomics models.ConclusionsThis study indicated potentials of multi-parametric MRI-based radiomics to assess the EGFR mutation and subtypes. The proposed clinical-radiomics nomogram models can be considered as non-invasive tools to assist clinicians in making individual treatment plans.</p
Table_2_Comprehensive analysis of prediction of the EGFR mutation and subtypes based on the spinal metastasis from primary lung adenocarcinoma.docx
PurposeTo investigate the use of multiparameter MRI-based radiomics in the in-depth prediction of epidermal growth factor receptor (EGFR) mutation and subtypes based on the spinal metastasis in patients with primary lung adenocarcinoma.MethodsA primary cohort was conducted with 257 patients who pathologically confirmed spinal bone metastasis from the first center between Feb. 2016 and Oct. 2020. An external cohort was developed with 42 patients from the second center between Apr. 2017 and Jun. 2021. All patients underwent sagittal T1-weighted imaging (T1W) and sagittal fat-suppressed T2-weight imaging (T2FS) MRI imaging. Radiomics features were extracted and selected to build radiomics signatures (RSs). Machine learning classify with 5-fold cross-validation were used to establish radiomics models for predicting the EGFR mutation and subtypes. Clinical characteristics were analyzed with Mann-Whitney U and Chi-Square tests to identify the most important factors. Nomogram models were developed integrating the RSs and important clinical factors.ResultsThe RSs derived from T1W showed better performance for predicting the EGFR mutation and subtypes compared with those from T2FS in terms of AUC, accuracy and specificity. The nomogram models integrating RSs from combination of the two MRI sequences and important clinical factors achieved the best prediction capabilities in the training (AUCs, EGFR vs. Exon 19 vs. Exon 21, 0.829 vs. 0.885 vs.0.919), internal validation (AUCs, EGFR vs. Exon 19 vs. Exon 21, 0.760 vs. 0.777 vs.0.811), external validation (AUCs, EGFR vs. Exon 19 vs. Exon 21, 0.780 vs. 0.846 vs.0.818). DCA curves indicated potential clinical values of the radiomics models.ConclusionsThis study indicated potentials of multi-parametric MRI-based radiomics to assess the EGFR mutation and subtypes. The proposed clinical-radiomics nomogram models can be considered as non-invasive tools to assist clinicians in making individual treatment plans.</p
Table_1_Comprehensive analysis of prediction of the EGFR mutation and subtypes based on the spinal metastasis from primary lung adenocarcinoma.docx
PurposeTo investigate the use of multiparameter MRI-based radiomics in the in-depth prediction of epidermal growth factor receptor (EGFR) mutation and subtypes based on the spinal metastasis in patients with primary lung adenocarcinoma.MethodsA primary cohort was conducted with 257 patients who pathologically confirmed spinal bone metastasis from the first center between Feb. 2016 and Oct. 2020. An external cohort was developed with 42 patients from the second center between Apr. 2017 and Jun. 2021. All patients underwent sagittal T1-weighted imaging (T1W) and sagittal fat-suppressed T2-weight imaging (T2FS) MRI imaging. Radiomics features were extracted and selected to build radiomics signatures (RSs). Machine learning classify with 5-fold cross-validation were used to establish radiomics models for predicting the EGFR mutation and subtypes. Clinical characteristics were analyzed with Mann-Whitney U and Chi-Square tests to identify the most important factors. Nomogram models were developed integrating the RSs and important clinical factors.ResultsThe RSs derived from T1W showed better performance for predicting the EGFR mutation and subtypes compared with those from T2FS in terms of AUC, accuracy and specificity. The nomogram models integrating RSs from combination of the two MRI sequences and important clinical factors achieved the best prediction capabilities in the training (AUCs, EGFR vs. Exon 19 vs. Exon 21, 0.829 vs. 0.885 vs.0.919), internal validation (AUCs, EGFR vs. Exon 19 vs. Exon 21, 0.760 vs. 0.777 vs.0.811), external validation (AUCs, EGFR vs. Exon 19 vs. Exon 21, 0.780 vs. 0.846 vs.0.818). DCA curves indicated potential clinical values of the radiomics models.ConclusionsThis study indicated potentials of multi-parametric MRI-based radiomics to assess the EGFR mutation and subtypes. The proposed clinical-radiomics nomogram models can be considered as non-invasive tools to assist clinicians in making individual treatment plans.</p
Transparent and Flexible Triboelectric Sensing Array for Touch Security Applications
Tactile sensors with large-scale
array and high sensitivity is essential for humanâmachine interaction,
smart wearable devices, and mobile networks. Here, a transparent and
flexible triboelectric sensing array (TSA) with fingertip-sized pixels
is demonstrated by integrating ITO electrodes, FEP film, and signal
transmission circuits on an undivided palm-sized polyethylene terephthalate
substrate. The sensing pixels can be triggered by the corresponding
external contact to induce the electrostatic potential in the transparent
electrodes without power consumption, which is individually recognized
by the sensor. By testing the response of the pixels, the electrical
characterization is systematically investigated. The proposed TSA
exhibits excellent durability, independence, and synchronicity, which
is able to realize real-time touch sensing, spatial mapping, and motion
monitoring. The integrated TSA has great potential for an active tactile
system, humanâmachine interface, wearable electronics, private
communication, and advanced security identification
Rotating-Sleeve TriboelectricâElectromagnetic Hybrid Nanogenerator for High Efficiency of Harvesting Mechanical Energy
Currently, a triboelectric nanogenerator (TENG) and an electromagnetic
generator (EMG) have been hybridized to effectively scavenge mechanical
energy. However, one critical issue of the hybrid device is the limited
output power due to the mismatched output impedance between the two
generators. In this work, impedance matching between the TENG and
EMG is achieved facilely through commercial transformers, and we put
forward a highly integrated hybrid device. The rotating-sleeve triboelectricâelectromagnetic
hybrid nanogenerator (RSHG) is designed by simulating the structure
of a common EMG, which ensures a high efficiency in transferring ambient
mechanical energy into electric power. The RSHG presents an excellent
performance with a short-circuit current of 1 mA and open-circuit
voltage of 48 V at a rotation speed of 250 rpm. Systematic measurements
demonstrate that the hybrid nanogenerator can deliver the largest
output power of 13 mW at a loading resistance of 8 kΩ. Moreover,
it is demonstrated that a wind-driven RSHG can light dozens of light-emitting
diodes and power an electric watch. The distinctive structure and
high output performance promise the practical application of this
rotating-sleeve structured hybrid nanogenerator for large-scale energy
conversion
A Soluble Bis-Chelated Gold(I) Diphosphine Compound with Strong Anticancer Activity and Low Toxicity
Gold-containing compounds have shown
anticancer potential, but
their clinical applications have been severely limited by poor stability
and high toxicity in vivo. Here, we report a novel soluble bis-chelated
goldÂ(I)âdiphosphine compound (GC20) with strong anticancer
activity and low toxicity. GC20 shows strong antiproliferation potency
against a broad spectrum of cancer cell lines including cisplatin-resistant
cancer cells (IC<sub>50</sub> â 0.5 ÎŒM) and significantly
reduces tumor growth in several tumor xenografts in mouse models at
doses as low as 2 mg/kg. Studies of its mechanism revealed that GC20
specifically inhibits the enzymatic activity of thioredoxin reductase
by binding to selenocysteine residue, without targeting other well-known
selenol and thiol groups contained in biomolecules. Remarkably, in
animal studies GC20 was shown to be well tolerated even at the high
dose of 8 mg/kg. Our results strongly suggest that GC20 represents
a promising candidate for the development of novel anticancer drugs
In Silico Identification of a Novel Hinge-Binding Scaffold for Kinase Inhibitor Discovery
To explore novel kinase hinge-binding
scaffolds, we carried out
structure-based virtual screening against p38α MAPK as a model
system. With the assistance of developed kinase-specific structural
filters, we identify a novel lead compound that selectively inhibits
a panel of kinases with threonine as the gatekeeper residue, including
BTK and LCK. These kinases play important roles in lymphocyte activation,
which encouraged us to design novel kinase inhibitors as drug candidates
for ameliorating inflammatory diseases and cancers. Therefore, we
chemically modified our substituted triazole-class lead compound to
improve the binding affinity and selectivity via a âminimal
decorationâ strategy, which resulted in potent and selective
kinase inhibitors against LCK (18 nM) and BTK (8 nM). Subsequent crystallographic
experiments validated our design. These rationally designed compounds
exhibit potent on-target inhibition against BTK in B cells or LCK
in T cells, respectively. Our work demonstrates that structure-based
virtual screening can be applied to facilitate the development of
novel chemical entities in crowded chemical space in the field of
kinase inhibitor discovery
Lithium-Ion Batteries: Charged by Triboelectric Nanogenerators with Pulsed Output Based on the Enhanced Cycling Stability
The triboelectric
nanogenerator (TENG) has been used to store its generated energy into
lithium-ion batteries (LIBs); however, the influences of its pulse
current and high voltage on LIB polarization and dynamic behaviors
have not been investigated yet. In this paper, it is found that LIBs
based on the phase transition reaction of the lithium storage mechanism
[LiFePO<sub>4</sub> (LFP) and Li<sub>4</sub>Ti<sub>5</sub>O<sub>12</sub> (LTO) electrodes] are more suitable for charging by TENGs. Thus,
the enhanced cycling capacity, Coulombic efficiency (nearly 100% for
LTO electrode), and energy storage efficiency (85.3% for the LFPâLTO
electrode) are successfully achieved. Moreover, the pulse current
has a positive effect on the increase of the Li-ion extraction, reducing
the charge-transfer resistance (<i>R</i><sub>ct</sub>) for
all studied electrodes as well (LFP, LiNi<sub>0.6</sub>Co<sub>0.2</sub>Mn<sub>0.2</sub>O<sub>2</sub>, LTO, and graphite). The excellent
cyclability, high Coulombic, and energy storage efficiencies demonstrated
the availability of storing pulsed energy generated by TENGs. This
research has provided a promising analysis to obtain an enhanced charging
methodology, which provides significant guidance for the scientific
research of the LIBs