Nonimmobilized Biomaterial Capillary Electrophoresis for Screening Drugs Targeting Human Glucose Transporter 1

Tumor cell membrane-coated continuous electrochemical sensor for GLUT1 inhibitor screening

Glucose transporter 1 (GLUT1) overexpression in tumor cells is a potential target for drug therapy, but few studies have reported screening GLUT1 inhibitors from natural or synthetic compounds. With current analysis techniques, it is difficult to accurately monitor the GLUT1 inhibitory effect of drug molecules in real-time. We developed a cell membrane-based glucose sensor (CMGS) that integrated a hydrogel electrode with tumor cell membranes to monitor GLUT1 transmembrane transport and screen for GLUT1 inhibitors in traditional Chinese medicines (TCMs). CMGS is compatible with cell membranes of various origins, including different types of tumors and cell lines with GLUT1 expression knocked down by small interfering RNA or small molecules. Based on CMGS continuous monitoring technique, we investigated the glucose transport kinetics of cell membranes with varying levels of GLUT1 expression. We used CMGS to determine the GLUT1-inhibitory effects of drug monomers with similar structures from Scutellaria baicalensis and catechins families. Results were consistent with those of the cellular glucose uptake test and molecular-docking simulation. CMGS could accurately screen drug molecules in TCMs that inhibit GLUT1, providing a new strategy for studying transmembrane protein-receptor interactions.

A study of protein–drug interaction based on solvent-induced protein aggregation by fluorescence correlation spectroscopy

Based on the inhibition of protein aggregation by drugs in organic solvent systems, we developed an effective method to study protein–drug interaction by fluorescence correlation spectroscopy.

[Research progress in the application of external field separation technology and microfluidic technology in the separation of micro/nanoscales]

The micro/nanoscales concerns interactions of entities with sizes in the range of 0.1-100 μm, such as biological cells, proteins, and particles. The separation of micro/nanoscales has been of immense significance for drug development, early-stage cancer detection, and customized precision therapy. For example, in recent years, rapid advances in the field of cell therapy have necessitated the development of simple and effective cell separation techniques. The isolation technique allows the collection of the required stem cells from complex samples. With the development of materials science and precision medicine, the separation of particles is also critical. The key physicochemical properties of micro/nanoscales are highly dependent on their specific size, shape, functional group, and mobility (based on the charged characteristics), which control their performance in the separation system. The current demand has made the simultaneous innovation of a separation system and an on-line detection platform imperative. Accordingly, various analytical methods involving the use of external forces, such as the flow field, magnetic field, electric field, and acoustic field, have been used for micro/nanoscales separation. Based on the physical and chemical parameters of the separation materials, these analytical methods can select different external force fields for micro/nanoscales separation, enabling real-time, accurate, efficient, and selective separation. However, at present, most of the applied field separation technologies require complex equipment and a large sample amount. This makes it crucial to miniaturize and integrate separation technologies for low-cost, rapid, and accurate micro/nanoscales separation. Microfluidic technology is a representative micro/nanoscales separation technology. It requires only a small volume of liquid, making it cost-effective; its high throughput enables continuous separation and analysis; its fast response in a microchip can allow many reactions; and finally, the miniaturization of the device allows the coupling of multiple detectors with the microchip. With the continuous growth and progress of microfluidic technology, some microfluidic platforms are now able to achieve the non-destructive separation of cells. They also enable on-line detection, offer high separation efficiency, and allow rapid separation for different biological samples. This review primarily summarizes recent advances in microfluidic chips based on flow field, electric field, magnetic field, acoustic field, and field separation technologies to improve the micro/nanoscales separation efficiency. This review also discusses the various external force fields of micro/nanoscales, such as a microparticle, single cell separation of substances classified introduction, and summarizes the advantages and disadvantages of their application and development. Finally, the prospect of the combined application of external field separation technology and microfluidic technology in the early screening of cancer cells and for precise micro/nanoscales separation is discussed, and the advantages and potential applications of the combined technology are proposed.

Detection of membrane receptors on per tumor cell by nonimmobilized cell capillary electrophoresis and a mathematic model

Folate receptors (FRs) are a class of valuable therapeutic target which is highly expressed on a variety of cancers. The accurate detection of the expression of FRs in different cells is conducive to improve the accuracy of FR targeted tumor therapy. Herein, a method based on nonimmobilized cell capillary electrophoresis (NICCE) combined with a mathematic model to quantify FRs on each single tumor cell was developed. At first, we studied the interactions between FA and A549, HT-29, HepG2, and U87MG cells by NICCE respectively, and calculated the kinetic parameters (Ka, k', ka, and kd). Next, we established a mathematic model to accurately determine the number of moles of FRs on per A549, HT-29, HepG2, and U87MG cell for the first time, that were (10.44 ± 0.53) × 10-19 mol, (34.32 ± 1.33) × 10-19 mol, (337.14 ± 10.11) × 10-19 mol, and (37.31 ± 2.13) × 10-19 mol. Then, these re-sults were proved to be consistent with the results of enzyme-linked immunosorbent assay (ELISA). Therefore, this method is simple, rapid, sensitive, and without protein separation or purification, which is expected to achieve clinical detection of cell membrane receptor expression level of cell membrane receptors on a single cell, which may be greatly beneficial to further clinical diagnosis and therapy.

Enzyme free glucose sensing by amino-functionalized silicon quantum dot

Silicon quantum dots have become one of the most popular nanomaterials in biological applications for their excellent biocompatibility and optical properties. Herein, we synthesized amino-functionalized silicon quantum dots (NH₂@SiQDs) via a simple microemulsion method, in which silicon tetrachloride and allylamine were used as source of silicon and functional group. NH₂@SiQDs exhibits good water-solubility, high fluorescence quantum yield and optical stability. A non-enzymatic biosensor of glucose was developed based on the fluorescence quenching of NH₂@SiQDs in response to glucose. The fluorescence response was linearly proportional to glucose in the concentration range of 1.0 × 10^-6-9.0 × 10^-5 mol/L and the detection limit was determined to be 3.0 × 10^-7 mol/L. The developed glucose sensor was successfully applied in blood glucose analysis of human serum. Satisfactory result that agreed very well with traditional method was obtained.

Structure-Based Discovery of a Selective KDM5A Inhibitor that Exhibits Anti-Cancer Activity via Inducing Cell Cycle Arrest and Senescence in Breast Cancer Cell Lines

Breast cancer is the one of the most frequent causes of female cancer mortality. KDM5A, a histone demethylase, can increase the proliferation, metastasis, and drug resistance of cancers, including breast cancer, and is thus an important therapeutic target. In the present work, we performed hierarchical virtual screening towards the KDM5A catalytic pocket from a chemical library containing 90,000 compounds. Using multiple biochemical methods, the cyclopenta[c]chromen derivative 1 was identified as the top candidate for KDM5A demethylase inhibitory activity. Compared with the well-known KDM5 inhibitor CPI-455 (18), 1 exhibited higher potency against KDM5A and much higher selectivity for KDM5A over both KDM4A and other KDM5 family members (KDM5B and KDM5C). Additionally, compound 1 repressed the proliferation of various KDM5A-overexpressing breast cancer cell lines. Mechanistically, 1 promoted accumulation of p16 and p27 by blocking KDM5A-mediated H3K4me3 demethylation, leading to cell cycle arrest and senescence. To date, compound 1 is the first cyclopenta[c]chromen-based KDM5A inhibitor reported, and may serve as a novel motif for developing more selective and efficacious pharmacological molecules targeting KDM5A. In addition, our research provides a possible anti-cancer mechanism of KDM5A inhibitors and highlights the feasibility and significance of KDM5A as a therapeutic target for KDM5A-overexpressing breast cancer.

Rapid screening of multi-target antitumor drugs by nonimmobilized tumor cells/tissues capillary electrophoresis

As there are more target categories on tumor cells/tissues than on receptor-overexpressing cells, and tumor tissues can better simulate TME, we established a new method of screening multi-target antitumor drugs by nonimmobilized tumor cells/tissues capillary electrophoresis under approximately tumor physiological environment. In this method, the natural structure and active conformation of the target proteins on tumor cells/tissues can be well maintained without separation and purification. Therefore, we successfully used this method to study the interactions between the Aidi injection (ADI)/its main components and tumor cells/tissues by optimizing a series of experimental conditions, discovered seven components with binding activity to A549 cells, five of them with specific interaction to tumor tissues, and calculated the binding kinetic parameters (K, k_a, k_d, and k'). Then, antitumor activity assays in vitro and in vivo were carried out to discover a new drug combination with higher targeting, better pharmaceutical efficacy, and lower toxic side effects. Finally, molecular docking studies were performed to investigate the potential target groups of the interactions between the effective drug combination and A549 cells/tissues. In summary, the method was verified to be valid and feasible, and can be easily transferred to a capillary array electrophoresis for high-throughput drug screening.