Nonpeptidic quinazolinone derivatives as dual nucleotide-binding oligomerization domain-like receptor 1/2 antagonists for adjuvant cancer chemotherapy

NLRs in tumor chemotherapy resistance: A double-edged sword

Nucleotide-binding oligomerization domain (NOD)-like receptors (NLRs) are a numerous family of cytoplasmic proteins. Members of this family not only function as innate immune sensors, but also serve as transcriptional regulators of major histocompatibility complex class II (MHC II) and major histocompatibility complex class I (MHC I) genes to activate adaptive immunity. Furthermore, NLRs are involved in mediating various signaling pathways, including the inflammasome. To date, extensive research has been conducted on the contradictory roles and mechanisms of NLRs in the occurrence, development, invasion, and metastasis of tumors within the tumor microenvironment (TME). The double-edged sword effect (either positive or negative role) of NLRs in the treatment of malignant tumors has attracted increasing attention in recent years, making these a promising bidirectional therapeutic target for such tumors. Rational utilization of the double-edged sword nature of NLRs can provide a feasible solution for improving the efficacy of malignant tumor treatment and overcoming chemotherapy resistance. This article provides a systematic review of the influence of the NLR family on chemosensitivity in different malignant tumors and the regulatory mechanisms of their upstream and downstream signaling pathways. In doing do, we aim to elucidate the dual role of NLRs in promoting and combating tumor chemotherapy resistance, and elucidate their application value in tumor chemotherapy resistance.

Selectively Antagonizing the NOD1-Mediated Inflammatory Signaling Pathway Mitigates the Gastric Inflammation Induced by Helicobacter pylori Infection

Helicobacter pylori (H. pylori) infection is characterized by the complex interplay between H. pylori and gastric disorders. It has been established that NOD1 can be activated by the peptidoglycan (PGN) present in the cell wall of H. pylori, serving as a key mediator of inflammation and initiating the RIP2/NF-κB and MAPK inflammatory signaling pathways. In this article, we reported on the development of a 2-chloroquinazolin-4-ol derivative 66 as a potent and selective antagonist of both human and mouse NOD1, which effectively inhibited the expression of inflammatory cytokines (IL-6, TNF-α) and chemokines (CXCL1, CXCL8) in immune and epithelial cells, as well as inflammatory cytokines (KC, IL-6) in a H. pylori-induced murine model of gastritis following oral administration. This study laid a foundation for treating gastritis induced by H. pylori infection.

Discovery of 2,3-Diaminoindole Derivatives as a Novel Class of NOD Antagonists

NOD1 and NOD2 are members of the pattern recognition receptors involved in the innate immune response. Overactivation of NOD1 is implicated in inflammatory disorders, multiple sclerosis, and cancer cell metastases. NOD1 antagonists would represent valuable pharmacological tools to gain further insight into protein roles, potentially leading to new therapeutic strategies. We herein report the expansion of the chemical space of NOD1 antagonists via a multicomponent synthetic approach affording a novel chemotype, namely, 2,3-diaminoindoles. These efforts resulted in compound 37, endowed with low micromolar affinity toward NOD1. Importantly, a proof-of-evidence of direct binding to NOD1 of Noditinib-1 and derivative 37 is provided here for the first time. Additionally, the combination of computational studies and NMR-based displacement assays enabled the characterization of the binding modality of 37 to NOD1, thus providing key unprecedented knowledge for the design of potent and selective NOD1 antagonists.

Extracellular vesicles from colorectal cancer cells promote metastasis via the NOD1 signalling pathway

Pattern-recognition receptors (PRRs) have been shown to promote tumour metastasis via sensing tumour cell-derived small extracellular vesicles (EVs). Nucleotide-binding oligomerisation domain 1 (NOD1), a cytoplasmic PRR, plays a role in colorectal cancer (CRC) by detecting bacterial products. However, the precise mechanisms underlying the effects of NOD1, following identification of CRC cell-derived EVs (CRC-EVs), to potentiate CRC liver metastasis (CRC-LM), remain poorly understood. Here, we demonstrate that CRC-EVs activate NOD1 in macrophages to initiate secretion of inflammatory cytokines and chemokines. NOD1-activated macrophages also promote CRC cell migration, while in a murine model of liver metastasis (LM), NOD1-deficient mice exhibit reduced metastasis following CRC-EV treatment. Furthermore, cell division cycle 42 (CDC42), a small Rho guanosine-5'-triphosphate (GTP)ase, is delivered by CRC-EVs into macrophages where it activates NOD1. In addition, EVs from the plasma of patients with CRC-LM mediate NOD1 activation in human peripheral blood mononuclear cells. Moreover, high NOD1 expression in tumour tissues is associated with poor prognosis of CRC-LM. Our findings suggest that CRC-EVs activate NOD1 to promote tumour metastasis, thus, NOD1 may serve as a potential target in the diagnosis and treatment of CRC-LM.

Terminal Phenoxy Group as a Privileged Moiety of the Drug Scaffold-A Short Review of Most Recent Studies 2013-2022

The terminal phenoxy group is a moiety of many drugs in use today. Numerous literature reports indicated its crucial importance for biological activity; thus, it is a privileged scaffold in medicinal chemistry. This review focuses on the latest achievements in the field of novel potential agents bearing a terminal phenoxy group in 2013-2022. The article provided information on neurological, anticancer, potential lymphoma agent, anti-HIV, antimicrobial, antiparasitic, analgesic, anti-diabetic as well as larvicidal, cholesterol esterase inhibitors, and antithrombotic or agonistic activities towards the adrenergic receptor. Additionally, for selected agents, the Structure-Activity-Relationship (SAR) is also discussed. Thus, this study may help the readers to better understand the nature of the phenoxy group, which will translate into rational drug design and the development of a more efficient drug. To the best of our knowledge, this is the first review devoted to an in-depth analysis of the various activities of compounds bearing terminal phenoxy moiety.

Novel Scaffolds for Modulation of NOD2 Identified by Pharmacophore-Based Virtual Screening

Nucleotide-binding oligomerization domain-containing protein 2 (NOD2) is an innate immune pattern recognition receptor responsible for the recognition of bacterial peptidoglycan fragments. Given its central role in the formation of innate and adaptive immune responses, NOD2 represents a valuable target for modulation with agonists and antagonists. A major challenge in the discovery of novel small-molecule NOD2 modulators is the lack of a co-crystallized complex with a ligand, which has limited previous progress to ligand-based design approaches and high-throughput screening campaigns. To that end, a hybrid docking and pharmacophore modeling approach was used to identify key interactions between NOD2 ligands and residues in the putative ligand-binding site. Following docking of previously reported NOD2 ligands to a homology model of human NOD2, a structure-based pharmacophore model was created and used to virtually screen a library of commercially available compounds. Two compounds, 1 and 3, identified as hits by the pharmacophore model, exhibited NOD2 antagonist activity and are the first small-molecule NOD2 modulators identified by virtual screening to date. The newly identified NOD2 antagonist scaffolds represent valuable starting points for further optimization.