Simultaneous detection of dual biomarkers using hierarchical MoS2 nanostructuring and nano-signal amplification-based electrochemical aptasensor toward accurate diagnosis of prostate cancer.

Accurate and reliable quantification of tumor biomarkers in clinical samples is of vital importance for early stage diagnosis and treatment of cancer. However, a poor specificity of prostate specific antigen (PSA) testing alone fostering overdetection and overtreatment, remains a great controversy in prostate cancer (PCa) screening. Here we report an electrochemical aptasensor using hierarchical MoS2 nanostructuring and SiO2 nano-signal amplification for simultaneous detection of dual PCa biomarkers, PSA and sarcosine, to enhance the diagnostic performance of PCa. In this strategy, hierarchical flower-like MoS2 nanostructures as functional interface accelerated intermolecular accessibility and improved DNA hybridization efficiency. Moreover, the spherical SiO2 nanoprobe that conjugated with both electroactive tags and DNA probes, allowed effective electrochemical signal amplification. By deliberately designing different hybridization modes, we individually implemented the optimization of PSA and sarcosine sensing system. Based on this, simultaneous determination of PSA and sarcosine was achieved, with limit of detection (LOD) down to 2.5 fg/mL and 14.4 fg/mL, respectively, as well as excellent selectivity. More importantly, using this approach, we could directly differentiate cancer patients with healthy ones for clinical serum samples. The ultrasensitive biosensor provides single-step analysis with simple operation and a small sample volume (∼12 µL), shedding new light on accurate diagnosis and early-detection of cancer in clinical applications.

The cytochrome P450 metabolic profiling of SMU-B in vitro, a novel small molecule tyrosine kinase inhibitor.

A novel small molecule tyrosine kinase inhibitor 6-[6-Amino-5-[(1R)-1-(2,6-dichloro-3-fluorophenyl)ethoxy]-3-pyridyl]-1'-methylspiro[indoline-3,4'-piperidine]-2-one (SMU-B) had good activity against ALK (anaplastic lymphoma kinase) and ROS1 (c-ros oncogene 1) targets in non-small-cell lung cancer. The excellent bioactivity of SMU-B highlights the importance of determining its metabolic traits, which could provide meaningful information for further pharmacokinetic studies of SMU-B. In this work, we studied the metabolism of SMU-B in human liver microsomes. Three metabolites of SMU-B were identified by a quadrupole-time of flight tandem mass spectrometer (Q-TOF-MS), and the metabolic pathways of SMU-B were demethylation, dehydrogenation and oxidation. CYP3A4/5 was the principal isoform involved in SMU-B metabolism, as shown by chemical inhibition and recombination human enzyme studies. Additionally, a predication with a molecular docking model confirmed that SMU-B could interact with the active sites of CYP3A4 and CYP3A5. This study illuminates the metabolic profile of the anti-tumor drug SMU-B, which will accelerate its clinical use.

Multi-triggered and enzyme-mimicking graphene oxide/polyvinyl alcohol/G-quartet supramolecular hydrogels.

Supramolecular hydrogels with stimuli-responsive behaviors under aqueous environments are attractive for their potential applications in controlled drug delivery, clinical diagnostics, and tissue engineering. However, there still remain challenges in developing multicomponent hydrogels as a new generation of "smart" soft materials with multiple intelligent functions toward complex biochemical stimuli. In this work, a three dimensional (3D)-nanostructured supramolecular hydrogel was fabricated using a simple and facile strategy via the self-assembly of graphene oxide (GO) nanosheets, poly(vinyl alcohol) (PVA) chains, and G-quartet/hemin (G4/H) motifs. The as-prepared GO/PVA/G4/H hydrogel exhibited a honeycomb-like 3D GO network architecture as well as excellent mechanical properties. Importantly, the hydrogel demonstrated pH-inducing reversible and cyclic phase transitions between solution and hydrogel states, which could be used as "ink" for injectable 3D printing of different shaped patterns. Also, binary AND and OR logic gates were successfully built by encapsulating enzymes into the hydrogels, which responded to a variety of biochemicals. In addition, the hydrogels showed excellent peroxidase-like activity, achieving the ultrasensitive detection of H2O2 at a concentration as low as 100 nM by their deposition on an electrochemical electrode. The design of multicomponent hydrogels opens up an avenue to fabricate novel "smart" soft matter for biological and medical applications.

Design, synthesis and biological evaluation of 2-amino-4-(1,2,4-triazol)pyridine derivatives as potent EGFR inhibitors to overcome TKI-resistance.

A new class of 2-amino-4-(1,2,4-triazol)pyridine derivatives were designed and synthesized as potent epidermal growth factor receptor inhibitors. In particular, compound 10c exhibited significant inhibitory against EGFRL858R/T790M, and also displayed potent anti-proliferative activity against non-small cell lung cancer cell line H1975. Besides, compound 10j showed potent inhibitory activity against glioblastoma cell line U87-EGFRvⅢ, which was at least 3-fold more potent than Osimertinib and 25-fold superior to Lazertinib. Moreover, molecular modeling and molecular dynamics simulations disclosed the binding model of the most active compound to the domain of EGFR. This contribution provides 2-amino-4-(1,2,4-triazol)pyridines as a new scaffold for EGFRT790M and/or EGFRvⅢ inhibitor.

Ultrasensitive aptamer-based protein assays based on one-dimensional core-shell nanozymes.

In enzyme-based immunoassys, the use of natural enzyme has been remarkably restricted by the inconvenience in preparation and storage, especially for point-of-care testing. Nanozymes, which can mimic the functions of natural enzymes, have been regarded as promising alternatives due to their robust stability and convenience in fabrication. Here we fabricated one-dimensional Fe3O4@C core-shell nanostructures via a solvent-thermal method. Thus prepared nanocomposites showed excellent peroxidase-like activity, capable of catalyzing chromogenic substrates into colored products in the presence of H2O2. We then developed a nanozyme-linked aptamer sorbent assay (NLASA) in a sandwich format, in which the as-prepared Fe3O4@C nanowires were employed as catalytic labels for colorimetric detection by naked eyes. In the detection of platelet-derived growth factor BB (PDGF-BB), this assay reliably exhibited detection limits as low as 10 fM, with a working range from 10 fM to 100 nM. By incorporating G-quadruplex-hemin DNAzyme with Fe3O4@C nanowires, the detection limit could be further lowered to 50 aM. The detection limit of PDGF-BB in 50% human serum was 100 fM. This ultrasensitive, cost-effective and easy-to-operate sensing platform offers new opportunities for protein detection in clinical diagnosis.

Design, synthesis and biological evaluations of 2-amino-4-(1-piperidine) pyridine derivatives as novel anti crizotinib-resistant ALK/ROS1 dual inhibitors.

ALK and ROS1 kinases have become promising therapeutic targets since Crizotinib was used to treat non-small-cell lung cancer clinically. Aiming to explore new potent inhibitors, a series of 2-amino-4-(1-piperidine) pyridine derivatives that stabilized a novel DFG-shifted conformation in the kinase domain of ALK were designed and synthesized on the base of lead compound A. Biological evaluation highlighted that most of these new compounds could also potently inhibit ROS1 kinase, leading to the promising inhibitors against both ROS1 and ALK. Among them, the representative compound 2e stood out potent anti-proliferative activity against ALK-addicted H3122 and ROS1-addicted HCC78 cell lines (IC50 = 6.27 µM and 10.71 µM, respectively), which were comparable to that of Crizotinib. Moreover, 2e showed impressive enzyme activity against clinically Crizotinib-resistant ALKL1196M with an IC50 value of 41.3 nM, which was about 2-fold more potent than that of Crizotinib. 2e also showed potent inhibitory activity in about 6-fold superior to Crizotinib (IC50: 104.7 nM vs. 643.5 nM) in Ba/F3 cell line harboring ROS1G2032R. Furthermore, molecular modeling disclosed that all the representative inhibitors could dock into the active site of ALK and ROS1, which gave a probable explanation of anti Crizotinib-resistant mutants. These results indicated that our work has established a path forward for the generation of anti Crizotinib-resistant ALK/ROS1 dual inhibitors.

Insight into binding mechanisms of EGFR allosteric inhibitors using molecular dynamics simulations and free energy calculations.

Lung cancer is the leading cause of cancer death, and epidermal growth factor receptor (EGFR) kinase domain mutations are a common cause of non-small-cell lung cancer (NSCLC), a major subtype of lung cancers. Patients harboring most of these mutations respond well to the EGFR inhibitors Gefitinib and Erlotinib initially, but soon develop resistance to them due to the emergence of the gatekeeper mutation T790M. The new-generation inhibitors such as AZD9291, HM61713, CO-1686 and WZ4002 can overcome T790M through covalent binding to Cys 797, but ultimately lose their efficacy upon the emergence of the C797S mutation that abolishes the covalent bonding. Allosteric inhibitors EAI001 and EAI045 are a new type of EGFR inhibitors that bind to EGFR away from the ATP-binding site and not relying on Cys 797. In this study, molecular dynamics simulations and free energy calculations were carried out on EAI001 and EAI045 in complex with EGFR, revealing the detailed inhibitory mechanism of EAI001 and EAI045 as EGFR allosteric inhibitor, which was expected to provide a basis for rational drug design of the EGFR allosteric inhibitors. Communicated by Ramaswamy H. Sarma.

Evolution strategy of ROS1 kinase inhibitors for use in cancer therapy.

The abnormal expression of c-ros oncogene1 receptor tyrosine kinase (ROS1) has been identified as clinically actionable oncogenic driver in non-small-cell lung cancer. Since crizotinib was approved by the US FDA for the treatment of advanced ROS1-positive non-small-cell lung cancer, ROS1 kinase has become a promising therapeutic target. Under the guidance of some advanced computer-assisted technologies, such as structure-based drug design, homology modeling and lipophilic efficiency parameters, several potent and selective inhibitors against wild-type and mutant ROS1 were designed and synthesized. In this article, we will review a series of scaffolds targeting ROS1 kinase from the hit-to-drug evolution strategies of their representative compounds and it is hoped that these design strategies would facilitate medicinal chemists to optimize the process of drug design.