Concise synthesis and biological activity evaluation of novel pyrazinyl-aryl urea derivatives against several cancer cell lines, which can especially induce T24 apoptotic and necroptotic cell death.

Based on the structural modification of regorafenib, 28 pyrazinyl-aryl urea derivatives were synthesized and their in vitro antiproliferative activities were evaluated. Six compounds (5-16, 5-17, 5-18, 5-19, 5-22, and 5-23) exhibited favorable inhibitory activity against the human bladder cancer T24 cell line, and 5-23 demonstrated the strongest inhibitory activity (IC50 = 4.58 ± 0.24 µM) with high selectivity. Compound 5-23 induced apoptosis in the low concentration range (≤7.5 µM) combined with shorter incubation time (≤10 h) via the activation of caspases, while high concentrations and prolonged incubation times led to necroptotic cell death by activating the RIPK1/RIPK3/MLKL signaling pathway. Induced apoptosis and necroptosis were closely associated with intracellular reactive oxygen species generation and decreased mitochondrial membrane potential. Compared with regorafenib, 5-23 displayed improved pharmacokinetic profiles in an in vivo rat model. Molecular docking and structure-activity relationship analyses were in agreement with the biological data. Compound 5-23 may be a potent anti-bladder cancer agent and this small molecule can be considered as a promising structure for further optimization.

Correction: Concise synthesis and biological activity evaluation of novel pyrazinyl-aryl urea derivatives against several cancer cell lines, which can especially induce T24 apoptotic and necroptotic cell death.

[This corrects the article DOI: 10.1039/D1MD00306B.].

Synthesis and in vitro anti-bladder cancer activity evaluation of quinazolinyl-arylurea derivatives.

Based on the structural modification of molecular-targeted agent sorafenib, a series of quinazolinyl-arylurea derivatives were synthesized and evaluated for their anti-proliferative activities against six human cancer cell lines. Compared with other cell lines tested, T24 was more sensitive to most compounds. Compound 7j exhibited the best profile with lower IC50 value and favorable selectivity. In this study, we focused on 7j-induced death forms of T24 cells and tried to elucidate the reason for its potent proliferative inhibitory activity. Compound 7j treatment could trigger three different cell death forms including apoptosis, ferroptosis, and autophagy; which form would occur depended on the concentrations and incubation time of 7j: (1) Lower concentrations within the initial 8 h of 7j treatment led to apoptosis-dependent death. (2) Ferroptosis and autophagy occurred in the case of higher concentrations combining with extended incubation time through effectively regulating the Sxc-/GPx4/ROS and PI3K/Akt/mTOR/ULK1 pathways, respectively. (3) The above death forms were closely associated with intracellular ROS generation and decreased mitochondrial membrane potential induced by 7j. In molecular docking and structure-activity relationship analyses, 7j could bind well to the active site of the corresponding receptor glutathione peroxidase 4 (GPx4). Compound 7j could be a promising lead for molecular-targeted anti-bladder cancer agents' discovery.

Arylurea Derivatives: A Class of Potential Cancer Targeting Agents.

Arylurea derivatives, an important class of small molecules, have received considerable attention in recent years due to their wide range of biological applications. Various molecular targeted agents with arylurea scaffold as potential enzyme/receptor inhibitors were constructed with the successful development of sorafenib and regorafenib. This review focuses on those arylureas possessing anti-cancer activities from 2010 to date. According to their different mechanisms of action, these arylureas are divided into the following six categories: (1) Ras/Raf/MEK/ERK signaling pathway inhibitors; (2) tumor angiogenesis inhibitors, their targets include Vascular Endothelial Growth Factor Receptors (VEGFRs), Fibroblast Growth Factor Receptors (FGFRs), Platelet-Derived Growth Factor Receptors (PDGFRs), Epidermal Growth Factor Receptors (EGFRs), Insulin-Like Growth Factor 1 Receptor (IGF-1R), Fmslike Tyrosine Kinase 3 (FLT3), c-Kit, MET, and Smoothened (Smo); (3) PI3K/AKT/mTOR signaling pathway inhibitors; (4) cell cycle inhibitors, their targets include Checkpoint Kinases (Chks), Cyclin- Dependent Kinases (CDKs), Aurora, SUMO activating enzyme 1 (SUMO E1), tubulin, and DNA; (5) tumor differentiation, migration, and invasion inhibitors, their targets include Matrix Metalloproteinases (MMPs), LIM kinase (Limk), Nicotinamide Phosphoribosyltransferase (Nampt), and Histone Deacetylase (HDAC); (6) arylureas from the rational modification of natural products. This review focuses on the Structure-Activity Relationships (SARs) of these arylureas. The structural evolution and current status of some typical anti-cancer agents used in clinic and/or in clinical trials are emphasized.

Oxoisoaporphine as Potent Telomerase Inhibitor.

Two compounds previously isolated from traditional Chinese medicine, Menispermum dauricum (DC), 6-hydroxyl-oxoisoaporphine (H-La), and 4,6-di(2-pyridinyl)benzo[h]isoindolo[4,5,6-de]quinolin-8(5H)-one (H-Lb), were known to have in vitro antitumor activity and to selectively bind human telomeric, c-myc, and bcl-2 G-quadruplexes (G4s). In this study, the binding properties of these two compounds to telomerase were investigated through molecular docking and telomeric repeat amplication protocol and silver staining assay (TRAP-silver staining assay). The binding energies bound to human telomerase RNA were calculated by molecular docking to be -6.43 and -9.76 kcal/mol for H-La and H-Lb, respectively. Compared with H-La, the ligand H-Lb more strongly inhibited telomerase activity in the SK-OV-3 cells model.

High in vivo antitumor activity of cobalt oxoisoaporphine complexes by targeting G-quadruplex DNA, telomerase and disrupting mitochondrial functions.

Two G-quadruplex ligands: [Co(H-La)2Cl2] (Co1) and [Co(Lb)2][CoCl4]⋅2H2O (Co2) have been synthesized and characterized. Two cobalt oxoisoaporphine complexes exhibited selective cytotoxicity to SK-OV-3/DDP cells than for HL-7702 cells. Cytotoxic mechanism studies indicated that both Co1 and Co2 were telomerase inhibitor targeting c-myc, telomere, and bcl-2 G4s, and triggering cell senescence and apoptosis, which caused S phase arrest. They also induced mitochondrial dysfunction. The better antitumor activity of Co2, which should be correlated with a moiety of 2-[5-(2-pyridinyl)-1H-pyrrol-2-yl]pyridine in the Lb. Importantly, Co2 at high doses showed at least the same level of tumor growth inhibition efficacy compared to that of cisplatin, and better in vivo safety profile.

Design, synthesis, and biological evaluation of novel quinazolinyl-diaryl urea derivatives as potential anticancer agents.

Through a structure-based molecular hybridization approach, a series of novel quinazolinyl-diaryl urea derivatives were designed, synthesized, and screened for their in vitro antiproliferative activities against three cancer cell lines (HepG2, MGC-803, and A549). Six compounds (7 g, 7 m, 7 o, 8 e, 8 g, and 8 m) showed stronger activity against a certain cell line compared with the positive reference drugs sorafenib and gefitinib. Among the six compounds, 8 g exhibited the strongest activity. In particular, compound 8 g induced A549 apoptosis, arrested cell cycle at the G0/G1 phase, elevated intracellular reactive oxygen species level, and decreased mitochondrial membrane potential. This compound can also effectively regulate the expression of apoptosis- and cell cycle-related proteins, and influence the Raf/MEK/ERK pathway. Molecular docking and structure-activity relationship analyses revealed that it can bind well to the active site of the receptor c-Raf, which was consistent with the biological data. Therefore, compound 8 g may be a potent antitumor agent, representing a promising lead for further optimization.

Synthesis, Fluorescence Properties, and Antiproliferative Potential of Several 3-Oxo-3H-benzo[f]chromene-2-carboxylic Acid Derivatives.

In this study, two series of 3-oxo-3H-benzo[f]chromene-2-carboxylic acid derivatives (compounds 5a-i and 6a-g) were synthesized. Their in vitro proliferation inhibitory activities against the A549 and NCI-H460 human non-small cell lung cancer (NSCLC) cell lines were evaluated. Their photophysical properties were measured. Among these target compounds, 5e exhibited the strongest antiproliferative activity by inducing apoptosis, arresting cell cycle, and elevating intracellular reactive oxygen species (ROS) level, suggesting that it may be a potent antitumor agent. In addition, compound 6g with very low cytotoxicity, demonstrated excellent fluorescence properties, which could be used as an effective fluorescence probe for biological imaging.

[Progress in the study of drug delivery system based on nanoparticles to overcome multi-drug resistance].

Multi-drug resistance (MDR) of cancer cells is a major cause of failure in chemotherapy. To the majority of anti-cancer drugs, tumor cells are able to generate a multi-drug resistance; but there is no common views on the mechanism of MDR. This review summarizes the use of drug delivery system based on nanoparticles to overcome MDR in recent years. Three kinds including non-modified, ligand-modified and multifunctional drug delivery systems are described. Especially, the mechanism of reversing MDR based on nanoparticles is covered. Through efficiently offsetting and antagonizing the action of pumping drugs out of the tumor cells, drug delivery system based on nanoparticles can increase the concentration of the drug in tumors, while reduce the side effects on normal cells and overcome multi-drug resistance. The use of drug-loaded nanoparticles, which combines nanotechnology with the strategy of active and passive targeting administration, has shown significant prospect improving cancer therapy.