An updated patent review of small-molecule c-Met kinase inhibitors (2018-present)

4-{3-[(Pyridin-4-ylmethyl)amino]-[1,2,4]triazolo[4,3-b][1,2,4]triazin-6-yl}phenol: An improved anticancer agent in hepatocellular carcinoma and a selective MDR1/MRP modulator

Hepatocellular carcinoma is the most common type of primary liver cancer. However, multidrug resistance (MDR) is a major obstacle to the effective chemotherapy of cancer cells. This report documents the rational design, synthesis, and biological evaluation of a novel series of triazolotriazines substituted with CH2NH-linked pyridine for use as dual c-Met/MDR inhibitors. Compound 12g with IC50 of 3.06 μM on HepG2 cells showed more potency than crizotinib (IC50 = 5.15 μM) in the MTT assay. In addition, 12g inhibited c-Met kinase at a low micromolar level (IC50 = 0.052 μM). 12g significantly inhibited P-gp and MRP1/2 efflux pumps in both cancerous HepG2 and BxPC3 cells starting from the lower concentrations of 3 and 0.3 µM, respectively. 12g did not inhibit MDR1 and MRP1/2 in noncancerous H69 cholangiocytes up to the concentration of 30 and 60 µM, respectively. Current results highlighted that cancerous cells were more susceptible to the effect of 12g than normal cells, in which the inhibition occurred only at the highest concentrations, suggesting a further interest in 12g as a selective anticancer agent. Overall, 12g, as a dual c-Met and P-gp/MRP inhibitor, is a promising lead compound for developing a new generation of anticancer agents.

Rational Design of PARP1/c-Met Dual Inhibitors for Overcoming PARP1 Inhibitor Resistance Induced by c-Met Overexpression

The emergence of resistance to PARP1 inhibitors poses a current therapeutic challenge, necessitating the development of novel strategies to overcome this obstacle. The present study describes the design and synthesis of a series of small molecules that target both PARP1 and c-Met. Among them, compound 16 is identified as a highly potent dual inhibitor, exhibiting excellent inhibitory activities against PARP1 (IC50 = 3.3 nM) and c-Met (IC50 = 32.2 nM), as well as demonstrating good antiproliferative effects on HR-proficient cancer cell lines and those resistant to PARP1 inhibitors. Importantly, compound 16 demonstrates superior antitumor potency compared to the PARP1 inhibitor Olaparib and the c-Met inhibitor Crizotinib, either alone or in combination, in MDA-MB-231 and HCT116OR xenograft models. These findings highlight the potential of PARP1/c-Met dual inhibitors for expanding the indications of PARP1 inhibitors and overcoming tumor cells' resistance to them.

A computer-aided drug design approach to explore novel type II inhibitors of c-Met receptor tyrosine kinase for cancer therapy: QSAR, molecular docking, ADMET and molecular dynamics simulations

Small molecules such as 4-phenoxypyridine derivatives have remarkable inhibitory activity against c-Met enzymatic activity and proliferation of cancer cell lines. Since there is a relationship between structure and biological activity of these molecules, these little compounds may have great potential for clinical pharmaceutical use against various types of cancer caused by c-Met activity. The purpose of this study was to remodel the structures of 4-phenoxypyridine derivatives to achieve strong inhibitory activity against c-Met and provide favorable pharmacokinetic properties for drug design and discovery. Therefore, this paper describes the structure-activity relationship and the rationalization of appropriate pharmacophore sites to improve the biological activity of the investigated molecules, based on bioinformatics techniques represented by a computer-aided drug design approach. Accordingly, robust and reliable 3D-QSAR models were developed based on CoMFA and CoMSIA techniques. As a result, 46 lead molecules were designed and their biological and pharmacokinetic activities were predicted in silico. Screening filters by 3D-QSAR, Molecular Docking, drug-like and ADME-Tox identified the computer-designed compounds P54 and P55 as the best candidates to achieve high inhibition of c-Met enzymatic activity compared to the synthesized template compound T14. Finally, through molecular dynamics simulations, the structural properties and dynamics of c-Met free and complex (PDB code: 3LQ8) in the presence of 4-phenoxypyridine-derived compounds in an aqueous environment are discussed. Overall, the rectosynthesis of the designed drug inhibitors (P54 and P55) and their in vitro and in vivo bioactivity evaluation may be attractive for design and discovery of novel drug effective to inhibit c-Met enzymatic activity.Communicated by Ramaswamy H. Sarma.

Blocking the HGF-MET pathway induces resolution of neutrophilic inflammation by promoting neutrophil apoptosis and efferocytosis

Inflammation resolution is an active process that involves cellular events such as apoptosis and efferocytosis, which are key steps in the restoration of tissue homeostasis. Hepatocyte growth factor (HGF) is a growth factor mostly produced by mesenchymal-origin cells and has been described to act via MET receptor tyrosine kinase. The HGF/MET axis is essential for determining the progression and severity of inflammatory and immune-mediated disorders. Here, we investigated the effect of blocking the HGF/MET signalling pathway by PF-04217903 on the resolution of established models of neutrophilic inflammation. In a self-resolving model of gout induced by MSU crystals, HGF expression on periarticular tissue peaked at 12 h, the same time point that neutrophils reach their maximal accumulation in the joints. The HGF/MET axis was activated in this model, as demonstrated by increased levels of MET phosphorylation in neutrophils (Ly6G⁺ cells). In addition, the number of neutrophils was reduced in the knee exudate after PF-04217903 treatment, an effect accompanied by increased neutrophil apoptosis and efferocytosis and enhanced expression of Annexin A1, a key molecule for inflammation resolution. Reduced MPO activity, IL-1β and CXCL1 levels were also observed in periarticular tissue. Importantly, PF-04217903 reduced the histopathological score and hypernociceptive response. Similar findings were obtained in LPS-induced neutrophilic pleurisy. In human neutrophils, the combined use of LPS and HGF increased MET phosphorylation and provided a prosurvival signal, whereas blocking MET with PF-04217903 induced caspase-dependent neutrophil apoptosis. Taken together, these data demonstrate that blocking HGF/MET signalling may be a potential therapeutic strategy for inducing the resolution of neutrophilic inflammatory responses.

Cu(BF4)2/AC-Catalyzed Synthesis of N-Substituted Anilines, N-Substituted 1,6-Naphthyridin-5(6H)-one, and Isoquinolin-1(2H)-one

Herein, we report practical Cu(BF₄)₂/activated carbon-catalyzed amination of various anilines, isoquinolinone, and naphthyridinone with aryl boronic acids. The ultrasonic and rotary evaporation treatment of the mixture of aq. Cu(BF₄)₂ and activated carbon in methanol afforded a novel Cu(II)-catalyst, which is air-stable and can be effectively applied in the Chan-Lam coupling reaction. The products of N-arylation were isolated in good to excellent yields at low catalytic loading. And Cu(BF₄)₂/AC also showed good reusability.

Metformin-induced downregulation of c-Met is a determinant of sensitivity in MDA-MB-468 breast cancer cells

Metformin, the widely used anti-diabetic drug, is emerging as a promising anti-cancer agent. However, response variation among different tumors remains a significant challenge. Hence, identification of the factors that determine metformin sensitivity is of greatest significance for its clinical implementation. In this study, we showed that MDA-MB-468 cells were most sensitive among the five breast cancer cell lines tested. We found that metformin-induced inhibition of MDA-MB-468 cells was correlated with downregulation of c-Met at both protein and mRNA levels. To understand the functional significance of c-Met downregulation in metformin-mediated tumor inhibition, we established control and c-Met overexpressing sublines of MDA-MB-468 cells (468/C and 468/Met) using lentiviral expression system. We demonstrated that overexpression of c-Met significantly attenuated metformin induced inhibition of MDA-MB-468 cells. Metformin-induced inhibition of ALDH1+ cells, which are enriched with cancer stem cells, was also abrogated in 468/Met cells as compared to 468/C cells. Signal transduction analysis of the paired cell lines indicated that c-Met-induced activation of STAT3 and AKT1, and upregulation of Gab1 are related to c-Met-modulated metformin responsiveness. These findings highlight c-Met as a potential key regulator of metformin-mediated inhibition of proliferation and stemness of breast cancer cells, indicating that c-Met overexpression may be a critical factor contributing to metformin resistance. The data also suggest that combination of metformin with c-Met inhibitors could be a useful strategy to improve metformin-mediated anti-cancer efficacies in breast cancer treatment.