Design, synthesis and pharmacological evaluation of N4,N6-disubstituted pyrimidine-4,6-diamine derivatives as potent EGFR inhibitors in non-small cell lung cancer

Pyrimidine-based dual-target inhibitors targeting epidermal growth factor receptor for overcoming drug resistance in cancer therapy(2006-present)

The epidermal growth factor receptor (EGFR) is a pivotal member of the epidermal growth factor receptor family, exerting crucial regulatory influence on cellular physiological processes, particularly in relation to cell growth, proliferation, and differentiation. In recent years, numerous EGFR inhibitors have been introduced to the market; unfortunately, the effectiveness of single-target EGFR inhibitors has been compromised due to the development of drug resistance caused by EGFR mutations. Despite attempts by some researchers to address this issue through combination therapy with two or more drugs, instances of dose-limiting toxicities have been observed. Consequently, EGFR dual-target inhibitors have emerged as a burgeoning field in cancer treatment, offering a novel therapeutic option for solid tumors with the added benefits of reduced risk of resistance, lower dosage requirements, diminished toxicity profiles, and enhanced efficacy. At present, a series of EGFR dual-target inhibitors with diverse structures have been developed successively. In this study, we initially investigated the pyrimidine-based EGFR dual-target inhibitors that have been reported in the past two decades and categorized them into aminopyrimidine derivatives and heterocyclic pyrimidine derivatives with increased molecular complexity. Subsequently, we comprehensively summarized the biological activity and structure-activity relationship of this class of inhibitors in the context of cancer therapy, while also exploring potential opportunities and challenges associated with their application in this field. The present study provides a partial framework to guide future endeavors in drug development.

Pyrimidine scaffold dual-target kinase inhibitors for cancer diseases: A review on design strategies, synthetic approaches, and structure-activity relationship (2018‒2023)

Cancer, the second leading cause of death globally, causes a significant threat to life. Despite advancements in the treatment of cancer, persistent challenges include severe side effects and the emergence of acquired drug resistance. Additionally, many traditional chemotherapy drugs show restricted efficacy and high toxicity, primarily attributed to their lack of selectivity. Thus, the development of drugs targeting protein kinases has emerged as a noteworthy priority for addressing human cancers. Medicinal chemists have shown considerable interest in the development of dual drug candidates as a strategy to create medicines that are safer, more efficient, and cost-effective. Furthermore, the Food and Drug Administration (FDA) has approved several dual-target drugs for anticancer treatment, emphasizing their lower risks of drug interactions and improved pharmacokinetics and safety profiles. This review focuses on the synthetic efforts, design strategies, and structure-activity relationship of the pyrimidine scaffold-based dual kinase inhibitors developed with anticancer potential within the recent 6 years (2018‒2023). Collectively, these strategies are expected to offer fresh perspectives on the future directions of pyrimidine-based dual-target kinase drug design, potentially advancing cancer therapeutics.

Inhibition of DDR1 promotes ferroptosis and overcomes gefitinib resistance in non-small cell lung cancer

Gefitinib is an epidermal growth factor receptor tyrosine kinase inhibitor (EGFR-TKI), which serves the critical pillar for the treatment of non-small cell lung cancer (NSCLC). However, the acquired resistance remains a challenge for its clinical application, for which, practical strategies to reverse gefitinib resistance in NSCLC are necessary. Ferroptosis, a programmed cell death driven by ferritin-dependent lipid peroxidation, involves in NSCLC progression and related chemoresistance. In our previous work, the self-synthesised EGFR inhibitor Yfq07 (N4, N6-disubstituted pyrimidine-4,6-diamine derivatives) displayed a considerable inhibitory effect on NSCLC both in vitro and in vivo. Herein, we observed that Yfq07 suppressed the proliferation of PC-9GR and HCC827GR cells, two gefitinib resistance NSCLC cell lines. Mechanically, Yfq07 inhibited the phosphorylation of the Discoidin Domain Receptor 1 (DDR1), a receptor tyrosine kinase (RTK) highly expressed in multiple cancers, accompanied by downregulated miR-3648 and upregulated SOCS2. Inhibition or knockdown of DDR1 suppressed the proliferation, migration, and invasion of gefitinib-resistant NSCLC cells, and on the other hand, also downregulated miR-3648 and promoted SOCS2 expression. More specifically, miR-3648 targeted the 3'UTR segment of SOCS2 mRNA and thus affecting the P-ERK signalling pathway to regulate the malignant behaviors of gefitinib-resistant NSCLC cells. Furthermore, Yfq07 also indirectly induced the ferroptosis of gefitinib-resistant NSCLC cells via SOCS2 triggered inhibition of xCT-GPX4 pathway. In conclusion, our study indicates that DDR1 inhibitor Yfq07 promotes ferroptosis and reverses gefitinib-resistance of NSCLC through DDR1-miR-3648-SOCS2 signalling pathway, which provides insights for targeted therapy of gefitinib-resistant NSCLC and drug developments targeting ferroptosis.

Targeting cancer using scaffold-hopping approaches: illuminating SAR to improve drug design

Scaffold hopping is a design approach involving alterations to the core structure of an already bioactive scaffold to generate novel molecules to discover bioactive hit compounds with innovative core structures. Scaffold hopping enhances selectivity and potency while maintaining physicochemical, pharmacodynamic (PD), and pharmacokinetic (PK) properties, including toxicity parameters. Numerous molecules have been designed based on a scaffold-hopping strategy that showed potent inhibition activity against multiple targets for the diverse types of malignancy. In this review, we critically discuss recent applications of scaffold hopping along with essential components of medicinal chemistry, such as structure-activity relationship (SAR) profiles. Moreover, we shed light on the limitations and challenges associated with scaffold hopping-based anticancer drug discovery.

Structural Perspectives in the Development of Novel EGFR Inhibitors for the Treatment of NSCLC

Non-small cell Lung cancer (NSCLC) is the most common type of lung cancer, which is caused by high consumption of tobacco and smoking. It is an epithelial lung cancer that affects about 2.2 million people across the globe, according to International Agency for Research on Cancer (IARC). Non-small cell lung cancer is a malignant tumor caused by EGFR mutation that occurs in the in-frame deletion of exon 19 and L858R point mutation in exon 21. Presently, clinically available inhibitors of EGFR (including erlotinib, lapatinib, gefitinib, selumetinib, etc.) are not specific and responsible for undesirable adverse effects. Moreover, to solve this problem search for newer EGFR inhibitors is the utmost need for the treatment and/or management of increasing lung cancer burden. The discovery of therapeutic agents that inhibit the specific target in tumorous cells, such as EGFR, is one of the successful strategies in treating many cancer therapies, including lung cancer. The exhaustive literature survey (2018-2023) has shown the importance of medicinally privileged pyrimidine derivatives together, fused and/or clubbed with other heterocyclic rings to design and develop novel EGFR inhibitors. Pyrimidine derivatives substituted with phenylamine, indole, pyrrole, piperazine, pyrazole, thiophene, pyridine and quinazoline derivatives substituted with phenylamine, pyrimidine, morpholine, pyrrole, dioxane, acrylamide, indole, pyridine, furan, pyrimidine, pyrazole etc. are privileged heterocyclic rings shown promising activity by inhibiting EGFR and TKIs. The present review summarizes the structure-activity relationship (SAR) and enzyme inhibitory activity, including IC50 values, percentage inhibition, and kinetic studies of potential compounds from various literature. The review also includes various aspects of molecular docking studies with compounds under clinical trials and patents filed on pyrimidine-based EGFR inhibitors in treating non-small cell lung cancer. The present review may benefit the medicinal chemist for developing novel compounds such as EGFR inhibitors.

Pyrimidine derivatives as EGFR tyrosine kinase inhibitors in NSCLC: - A comprehensive review

EGFR positive NSCLC due to primary mutation (EGFR DEL19 & L858R) has been recognized as a crucial mediator of tumor progression. This led to the development and approval of EGFR tyrosine kinase inhibitors which addresses EGFR mediated NSCLC but fail to show potency after initial months of therapy due to acquired resistance (EGFR T790M, EGFR C797S). Extensive research allowed identification of drugs for EGFR positive NSCLC, wherein the majority of compounds have a pyrimidine substructure offering marked therapeutic benefits compared to chemotherapy. This current review outlines the diverse pyrimidine derivatives with amino-linked and fused pyrimidine scaffolds such as furo-pyrimidine, pyrimido-pyrimidine, thieno-pyrimidine, highlighting pyrimidine EGFR TK inhibitors reported in research emphasizing structural aspects, design approaches, inhibition potential. selectivity profile towards mutant EGFR conveyed through biological evaluation studies. Furthermore, mentioning the in-silico interaction profile of synthesized compounds for evaluating the binding affinity with key amino acids. The epilogue of review focuses on the recent research that drives forward to aid in the discovery and development of substituted amino and fused scaffolds of pyrimidine that can counteract the mutations and effectively manage EGFR positive NSCLC.

Design and Synthesis of New Hydantoin Acetanilide Derivatives as Anti-NSCLC Targeting EGFRL858R/T790M Mutations

Epidermal Growth Factor Receptor (EGFR), its wild type and mutations L858R/T790M, is overexpressed in non-small cell lung cancer (NSCLC) patients and is considered an inevitable oncology target. However, while the potential EGFR inhibitors have been represented in the literature, their cellular activity failed to establish broad potency against EGFR and its mutations. This study identifies a new series of EGFRL858R/T790M inhibitors bearing hydantoin acetanilides. Most compounds revealed strong antiproliferative activity in a range of NSCL cancer models (A549, H1975, and PC9), in which 5a and 5f were the most potent. Compounds 5a and 5f possessed potent anticancer activity on H1975 cells with IC50 values of 1.94 and 1.38 µM, respectively, compared to 9.70 µM for erlotinib. Favorably, 5a and 5f showed low activity on WI-38 normal cells. Western blotting and an EGFR kinase assay test proved the significant EGFR inhibitory activity of 5a. Besides, active hydantoin derivative 5a strongly arrested the cell cycle at the sub G1 and S phases and triggered apoptosis in A549 cells. These results imply that 5a could be considered a promising lead compound for additional development as a potential active agent for anticancer therapy.

Discovery of Anilino-1,4-naphthoquinones as Potent EGFR Tyrosine Kinase Inhibitors: Synthesis, Biological Evaluation, and Comprehensive Molecular Modeling

Epidermal growth factor receptor (EGFR) has been recognized as one of the attractive targets for anticancer drug development. Herein, a set of anilino-1,4-naphthoquinone derivatives (3-18) was synthesized and investigated for their anticancer and EGFR inhibitory potentials. Among all tested compounds, three derivatives (3, 8, and 10) were selected for studying EGFR inhibitory activity (in vitro and in silico) due to their most potent cytotoxic activities against six tested cancer cell lines (i.e., HuCCA-1, HepG2, A549, MOLT-3, MDA-MB-231, and T47D; IC50 values = 1.75-27.91 μM), high selectivity index (>20), and good predicted drug-like properties. The experimental results showed that these three promising compounds are potent EGFR inhibitors with nanomolar IC50 values (3.96-18.64 nM). Interestingly, the most potent compound 3 bearing 4-methyl substituent on the phenyl ring displayed 4-fold higher potency than the known EGFR inhibitor, erlotinib. Molecular docking, molecular dynamics simulation, and MM/GBSA-based free energy calculation revealed that van der Waals force played a major role in the accommodations of compound 3 within the ATP-binding pocket of EGFR. Additionally, the 4-CH3 moiety of the compound was noted to be a key chemical feature contributing to the highly potent EGFR inhibitory activity via its formations of alkyl interactions with A743, K745, M766, and L788 residues as well as additional interactions with M766 and T790.

Design, synthesis, and SAR studies of novel 4-methoxyphenyl pyrazole and pyrimidine derivatives as potential dual tyrosine kinase inhibitors targeting both EGFR and VEGFR-2

Guided by the pharmacophoric features of both EGFR and VEGFR-2 antagonists, two novel series of 4-methoxyphenyl pyrazole and pyrimidine derivatives [(4a-c) and (5a-c, 6, 7a-c, 8, 9, 10, 11a,c, 12, 13a-c, 14a-c, and 15a,b)], respectively, were designed and synthesized as dual EGFR/VEGFR-2 inhibitors. Interestingly, compound 12 showed very strong antiproliferative effects towards all the five studied cell lines (HepG-2, MCF-7, MDA-231, HCT-116, and Caco-2) with IC₅₀ values of 3.74, 7.81, 4.85, 2.96, and 9.27 µM, respectively. Also, it achieved the highest inhibitory activities against both EGFR and VEGFR-2 as well (IC₅₀ = 0.071 and 0.098 µM) compared to the two reference drugs, erlotinib (IC₅₀ = 0.063 µM) and sorafenib (IC₅₀ = 0.041 µM), respectively. Moreover, four compounds (4a, 7a, 7c, and 12) were selected for further evaluation through cell cycle analysis and Annexin V-based flow cytometry assay in the HepG-2 cell line. In addition, deep computational studies including molecular docking, physicochemical properties, profiling pharmacokinetics, ADMET studies, and toxicity predictions were performed for the designed compounds to evaluate the prospective drug candidates. Finally, analyzing the structure-activity relationship (SAR) of the new derivatives gives us a lot of interesting promising results which could help medicinal chemists to design more potent drug candidates soon as well.

Pyrimidine-based EGFR TK inhibitors in targeted cancer therapy

Despite significant improvements of new treatment options, cancer continues to represent as one of the most common and fatal disease. The EGFR signaling pathway is considered as a significant approach in targeted therapy of cancers. Blocking the EGFR-driven pathway by inhibiting the intracellular tyrosine kinase domain of EGFR have shown considerable improvement in cancer therapy. In an effort to identify EGFR tyrosine kinase inhibitors (TKI), several small molecules especially pyrimidine containing derivatives have been designed by applying molecular simulation and evaluated the emergence of epigenetic mutation and resistance problems restricted the long-term effectiveness of such medication and explained the need for further investigations in this field. In recent years, the studies have been focused on genetic alterations on EGFR tyrosine kinase domain, which led to the design and synthesis of more selective and effective inhibitors. Herein, we give an overview of the importance and status of EGFR inhibitors in cancer therapy. In addition, we provide an update of the recent advances in design, discovery and development of novel pyrimidine containing compounds as promising selective EGFR TK inhibitors.

Mono- and Diamination of 4,6-Dichloropyrimidine, 2,6-Dichloropyrazine and 1,3-Dichloroisoquinoline with Adamantane-Containing Amines

N-heteroaryl substituted adamantane-containing amines are of substantial interest for their perspective antiviral and psychotherapeutic activities. Chlorine atom at alpha-position of N-heterocycles has been substituted by the amino group using convenient nucleophilic substitution reactions with a series of adamantylalkylamines. The prototropic equilibrium in these compounds was studied using NMR spectroscopy. The introduction of the second amino substituent in 4-amino-6-chloropyrimidine, 2-amino-chloropyrazine, and 1-amino-3-chloroisoquinoline was achieved using Pd(0) catalysis.

Recent advances of dual FGFR inhibitors as a novel therapy for cancer

Fibroblast growth factor receptor (FGFR) includes four highly conserved transmembrane receptor tyrosine kinases (FGFR1-4). FGF and FGFR regulate many biological processes, such as angiogenesis, wound healing and tissue regeneration. The abnormal expression of FGFR is related to the tumorigenesis, tumor progression and drug resistance of anti-tumor treatments in many types of tumors. Nowadays there are many anti-cancer drugs targeting FGFR. However, traditional single-target anti-tumor drugs are easy to acquire drug resistance. The therapeutic effect can be enhanced by simultaneously inhibiting FGFR and another target (such as VEGFR, EGFR, PI3K, CSF-1R, etc.). We know drug combination can bring problems such as drug interactions. Therefore, the development of FGFR dual target inhibitors is an important direction. In this paper, we reviewed the research on dual FGFR inhibitors in recent years and made brief comments on them.

Discovery of 4,6-pyrimidinediamine derivatives as novel dual EGFR/FGFR inhibitors aimed EGFR/FGFR1-positive NSCLC

FGF2-FGFR1 autocrine pathway activation reduces the sensitivity of non-small cell lung cancer (NSCLC) cells to EGFR inhibitors like Gefitinib. Therefore, dual-specific drugs targeting EGFR and FGFR with high selectivity and activity are required. Through structure analysis of excellent EGFR inhibitors and FGFR inhibitors, we designed and synthesized 33 4,6-pyrimidinediamine derivatives as dual EGFR and FGFR inhibitors and selected BZF 2 as a potential EGFR and FGFR inhibitor after initial cell screening. Then, through kinase testing and western blot analysis, BZF 2 was defined as a dual EGFR and FGFR inhibitor with high selectivity ¹and activity. Biological evaluation of NSCLC cell lines with the FGF2-FGFR1 autocrine loop indicated that BZF 2 significantly inhibited cell proliferation (IC₅₀ values for H226 and HCC827 GR were 2.11 μM, and 0.93 μM, respectively), cell migration, and induced cell apoptosis and cell cycle arrest. Anti-tumor activity test in vivo showed that BZF 2 obviously shrank tumor size. Therefore, BZF 2 is a highly selective and potent dual EGFR/FGFR compound with promising therapeutic effects against EGFR/FGFR1-positive NSCLC.