Design, synthesis and evaluation of sulfonylurea-containing 4-phenoxyquinolines as highly selective c-Met kinase inhibitors

Anticancer Drug Discovery By Structure-Based Repositioning Approach

Despite the tremendous progress that has occurred in recent years in cell biology and oncology, in chemical, physical and computer sciences, the disease cancer has continued as the major cause of death globally. Research organizations, academic institutions and pharmaceutical companies invest huge amounts of money in the discovery and development of new anticancer drugs. Though much effort is continuing and whatever available approaches are being attempted, the success of bringing one effective drug into the market has been uncertain. To overcome problems associated with drug discovery, several approaches are being attempted. One such approach has been the use of known, approved and marketed drugs to screen these for new indications, which have gained considerable interest. This approach is known in different terms as "drug repositioning or drug repurposing." Drug repositioning refers to the structure modification of the active molecule by synthesis, in vitro/ in vivo screening and in silico computational applications where macromolecular structure-based drug design (SBDD) is employed. In this perspective, we aimed to focus on the application of repositioning or repurposing of essential drug moieties present in drugs that are already used for the treatment of some diseases such as diabetes, human immunodeficiency virus (HIV) infection and inflammation as anticancer agents. This review thus covers the available literature where molecular modeling of drugs/enzyme inhibitors through SBDD is reported for antidiabetics, anti-HIV and inflammatory diseases, which are structurally modified and screened for anticancer activity using respective cell lines.

Design, synthesis, and biological evaluation of thiazole/thiadiazole carboxamide scaffold-based derivatives as potential c-Met kinase inhibitors for cancer treatment

As part of our continuous efforts to discover novel c-Met inhibitors as antitumor agents, four series of thiazole/thiadiazole carboxamide-derived analogues were designed, synthesised, and evaluated for the in vitro activity against c-Met and four human cancer cell lines. After five cycles of optimisation on structure-activity relationship, compound 51am was found to be the most promising inhibitor in both biochemical and cellular assays. Moreover, 51am exhibited potency against several c-Met mutants. Mechanistically, 51am not only induced cell cycle arrest and apoptosis in MKN-45 cells but also inhibited c-Met phosphorylation in the cell and cell-free systems. It also exhibited a good pharmacokinetic profile in BALB/c mice. Furthermore, the binding mode of 51am with both c-Met and VEGFR-2 provided novel insights for the discovery of selective c-Met inhibitors. Taken together, these results indicate that 51am could be an antitumor candidate meriting further development.

Design, synthesis and biological evaluation of sulfonylamidines as potent c-Met inhibitors by enhancing hydrophobic interaction

The dysregulation of c-Met kinase has emerged as a significant contributing factor for the occurrence, progression, poor clinical outcomes and drug resistance of various human cancers. In our ongoing pursuit to identify promising c-Met inhibitors as potential antitumor agents, a docking study of the previously reported c-Met inhibitor 7 revealed a large unoccupied hydrophobic pocket, which could present an opportunity for further exploration of structure-activity relationships to improve the binding affinity with the allosteric hydrophobic back pocket of c-Met. Herein we performed structure-activity relationship and molecular modeling studies based on lead compound 7. The collective endeavors culminated in the discovery of compound 21j with superior efficacy to 7 and positive control foretinib by increasing the hydrophobic interaction with the hydrophobic back pocket of c-Met active site.

Recent progress on vascular endothelial growth factor receptor inhibitors with dual targeting capabilities for tumor therapy

Vascular endothelial growth factor receptors (VEGFRs) are a family of receptor protein tyrosine kinases that play an important role in the regulation of tumor-induced angiogenesis. Currently, VEGFR inhibitors have been widely used in the treatment of various tumors. However, current VEGFR inhibitors are limited to a certain extent due to limited clinical efficacy and potential toxicity, which hinder their clinical application. Thus, the development of new strategies to improve the clinical outcomes and minimize the toxic effects of VEGFR inhibitors is required. Given the synergistic effect of VEGFR and other therapies in tumor development and progression, VEGFR dual-target inhibitors are becoming an attractive approach due to their favorable pharmacodynamics, low toxicity, and anti-resistant effects. This perspective provides an overview of the development of VEGFR dual-target inhibitors from multiple aspects, including rational target combinations, drug discovery strategies, structure–activity relationships and future directions.

Design, synthesis and biological evaluation of 4-phenoxy-pyridine/pyrimidine derivatives as dual VEGFR-2/c-Met inhibitors

A class of 4-phenoxy-pyridine/pyrimidine derivatives (23a–23p and 24a–24h) were designed, synthesized and evaluated as potent dual VEGFR-2/c-Met inhibitors.

Recent contributions of quinolines to antimalarial and anticancer drug discovery research

Quinoline, a privileged scaffold in medicinal chemistry, has always been associated with a multitude of biological activities. Especially in antimalarial and anticancer research, quinoline played (and still plays) a central role, giving rise to the development of an array of quinoline-containing pharmaceuticals in these therapeutic areas. However, both diseases still affect millions of people every year, pointing to the necessity of new therapies. Quinolines have a long-standing history as antimalarial agents, but established quinoline-containing antimalarial drugs are now facing widespread resistance of the Plasmodium parasite. Nevertheless, as evidenced by a massive number of recent literature contributions, they are still of great value for future developments in this field. On the other hand, the number of currently approved anticancer drugs containing a quinoline scaffold are limited, but a strong increase and interest in quinoline compounds as potential anticancer agents can be seen in the last few years. In this review, a literature overview of recent contributions made by quinoline-containing compounds as potent antimalarial or anticancer agents is provided, covering publications between 2018 and 2020.

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

INTRODUCTION

c-Met tyrosine kinase receptor is a high-affinity ligand of hepatocyte growth factor (HGF). c-Met is widely expressed in a variety of normal human tissues, but shows abnormally high expression, amplification or mutation in tumour tissues such as lung, gastric and breast cancers. Therefore, the use of c-Met as a target can achieve the inhibition of a series of abnormal physiological processes such as tumourigenesis, development and metastasis. A number of small molecule tyrosine kinase inhibitors targeting c-Met have been successfully marketed.

AREAS COVERED

This article reviews recent advances in patented c-Met small molecule inhibitors and their inhibitory activity against various cancer cells from 2018 to date.

EXPERT OPINION

To date, small molecule inhibitors targeting c-Met have demonstrated impressive therapeutic efficacy in the clinical setting. Most recent patents have focused on addressing the direction of c-Met amplification and overexpression. Despite the great success in the development of selective c-Met inhibitors, the effects of bypass secretion and mutagenesis have led to a need for new c-Met small molecule inhibitors that are safe, efficient, selective and less toxic with novel structures and effective against other targets.

Research Progress of Small Molecule VEGFR/c-Met Inhibitors as Anticancer Agents (2016-Present)

Vascular endothelial growth factor receptor 2 (VEGFR-2) binds to VEGFR-A, VEGFR-C and VEGFR-D and participates in the formation of tumor blood vessels, mediates the proliferation of endothelial cells, enhances microvascular permeability, and blocks apoptosis. Blocking or downregulating the signal transduction of VEGFR is the main way to discover new drugs for many human angiogenesis-dependent malignancies. Mesenchymal epithelial transfer factor tyrosine kinase (c-Met) is a high affinity receptor for hepatocyte growth factor (HGF). Abnormal c-Met signaling plays an important role in the formation, invasion and metastasis of human tumors. Therefore, the HGF/c-Met signaling pathway has become a significant target for cancer treatment. Related studies have shown that the conduction of the VEGFR and c-Met signaling pathways has a synergistic effect in inducing angiogenesis and inhibiting tumor growth. In recent years, multi-target small molecule inhibitors have become a research hotspot, among which the research of VEGFR and c-Met dual-target small molecule inhibitors has become more and more extensive. In this review, we comprehensively summarize the chemical structures and biological characteristics of novel VEGFR/c-Met dual-target small-molecule inhibitors in the past five years.

Design, synthesis and biological evaluation of novel N-sulfonylamidine-based derivatives as c-Met inhibitors via Cu-catalyzed three-component reaction

In our continuing efforts to develop novel c-Met inhibitors as potential anticancer candidates, a series of new N-sulfonylamidine derivatives were designed, synthesized via Cu-catalyzed multicomponent reaction (MCR) as the key step, and evaluated for their in vitro biological activities against c-Met kinase and four cancer cell lines (A549, HT-29, MKN-45 and MDA-MB-231). Most of the target compounds showed moderate to significant potency at both the enzyme-based and cell-based assay and possessed selectivity for A549 and HT-29 cancer cell lines. The preliminary SAR studies demonstrated that compound 26af (c-Met IC₅₀ = 2.89 nM) was the most promising compound compared with the positive foretinib, which exhibited the remarkable antiproliferative activities, with IC₅₀ values ranging from 0.28 to 0.72 μM. Mechanistic studies of 26af showed the anticancer activity was closely related to the blocking phosphorylation of c-Met, leading to cell cycle arresting at G2/M phase and apoptosis of A549 cells by a concentration-dependent manner. The promising compound 26af was further identified as a relatively selective inhibitor of c-Met kinase, which also possessed an acceptable safety profile and favorable pharmacokinetic properties in BALB/c mouse. The favorable drug-likeness of 26af suggested that N-sulfonylamidines may be used as a promising scaffold for antitumor drug development. Additionally, the docking study and molecular dynamics simulations of 26af revealed a common mode of interaction with the binding site of c-Met. These positive results indicated that compound 26af is a potential anti-cancer candidate for clinical trials, and deserves further development as a selective c-Met inhibitor.