Design and Evaluation of Potent EGFR Inhibitors through the Incorporation of Macrocyclic Polyamine Moieties into the 4-Anilinoquinazoline Scaffold

Unraveling the future: Innovative design strategies and emerging challenges in HER2-targeted tyrosine kinase inhibitors for cancer therapy

Human epidermal growth factor receptor 2 (HER2) is a transmembrane receptor-like protein with tyrosine kinase activity that plays a vital role in processes such as cell proliferation, differentiation, and angiogenesis. The degree of malignancy of different cancers, notably breast cancer, is strongly associated with HER2 amplification, overexpression, and mutation. Currently, widely used clinical HER2 tyrosine kinase inhibitors (TKIs), such as lapatinib and neratinib, have several drawbacks, including susceptibility to drug resistance caused by HER2 mutations and adverse effects from insufficient HER2 selectivity. To address these issues, it is essential to create innovative HER2 TKIs with enhanced safety, effectiveness against mutations, and high selectivity. Typically, SPH5030 has advanced to phase I clinical trials for its strong suppression of four HER2 mutations. This review discusses the latest research progress in HER2 TKIs, with a focus on the structural optimization process and structure-activity relationship analysis. In particular, this study highlights promising design strategies to address these challenges, providing insightful information and inspiration for future development in this field.

Structure-Activity Relationship Studies Based on Quinazoline Derivatives as EGFR Kinase Inhibitors (2017-Present)

The epidermal growth factor receptor (EGFR) plays a critical role in the tumorigenesis of various forms of cancer. Targeting the mutant forms of EGFR has been identified as an attractive therapeutic approach and led to the approval of three generations of inhibitors. The quinazoline core has emerged as a favorable scaffold for the development of novel EGFR inhibitors due to increased affinity for the active site of EGFR kinase. Currently, there are five first-generation (gefitinib, erlotinib, lapatinib, vandetanib, and icotinib) and two second-generation (afatinib and dacomitinib) quinazoline-based EGFR inhibitors approved for the treatment of various types of cancers. The aim of this review is to outline the structural modulations favorable for the inhibitory activity toward both common mutant (del19 and L858R) and resistance-conferring mutant (T790M and C797S) EGFR forms, and provide an overview of the newly synthesized quinazoline derivatives as potentially competitive, covalent or allosteric inhibitors of EGFR.

Antitumor activity and mechanisms of dual EGFR/DNA-targeting strategy for the treatment of lung cancer with EGFRL858R/T790M mutation

Dual- or multi-targeted EGFR inhibitors as single drugs can overcome EGFR inhibitor resistance and circumvent many disadvantages of combination therapy. In this work, fifteen 4-anilinoquinazoline derivatives bearing nitrogen mustard or hemi mustard moieties were designed and synthesized as dual EGFR-DNA targeting anticancer agents. Structures of target molecules were confirmed by ¹H NMR, ¹³C NMR and HR-MS, and evaluated for their in vitro anti-proliferative activities using MTT assay. Compound 6g emerged as the most potent derivative against mutant-type H1975 cells with IC₅₀ value of 1.45 μM, which exhibited 4-fold stronger potency than Chl/Gef (equimolar combination of chlorambucil and gefitinib). Kinase inhibition studies indicated that 6g showed excellent inhibitory effect on EGFR^L858R/T790M enzyme, which was 8.6 times more effective than gefitinib. Mechanistic studies indicated that 6g induced apoptosis of H1975 cells in a dose-dependent manner and caused DNA damage. Importantly, 6g could significantly inhibit the expression of p-EGFR and its downstream p-AKT and p-ERK in H1975 cells. Molecular docking was also performed to gain insights into the ligand-binding interactions of 6g inside EGFR^WT and EGFR^L858R/T790M binding sites. Moreover, 6g efficiently inhibited tumor growth in the H1975 xenograft model without side effects.

An approach to pharmacological targets of pyrrole family from a medicinal chemistry viewpoint

Pyrrole is one of the most widely used heterocycles in the pharmaceutical industry. Due to the importance of pyrrole structure in drug design and development, herein, we tried to conduct an extensive review of the bioactive pyrrole based compounds reported recently. The bioactivity of pyrrole derivatives varies, so in the review, we categorized them based on their direct pharmacologic targets. Therefore, readers are able to find the variety of biologic targets for pyrrole containing compounds easily. This review explains around seventy different biologic targets for pyrrole based derivatives, so, it is helpful for medicinal chemists in design and development novel bioactive compounds for different diseases. This review presents an extensive meaningful structure activity relationship for each reported structure as much as possible. The review focuses on papers published between 2018 and 2020.

Identification of tripeptides against tyrosine kinase domain of EGFR for lung cancer cell inhibition by in silico and in vitro studies

Epidermal growth factor receptor tyrosine kinase domain (EGFR-TK) has been one of the prominent targets for therapeutics of several human cancers, in particular non-small cell lung cancer. Although several small chemical compounds targeting EGFR-TK have been approved by FDA for treatment of such a cancer, the discovery of a new class of EGFR-TK inhibitors, for example, small peptides, is still desired. In this study, using molecular docking-based virtual screening, we selected five small peptides with high docking scores from eight thousand peptides as candidate compounds against EGFR-TK. Among five, the tripeptide WFF had the most potency to suppress the survival of non-small cell lung cancer cells but had the least toxicity to human liver cancer cells. Our in vitro kinase assays showed that WFF exhibited much lower inhibitory activity against purified EGFR-TK than the drug erlotinib (i.e., IC₅₀  values of ≈ 0.62 μM vs ≈ 7.57 nM, respectively). The relative free binding energies estimated from molecular dynamic simulations were consistent with the in vitro experiments in which the WFF bound had a lower affinity than erlotinib bound to EGFR-TK (i.e., ΔG_bind values of -20.3 kJ/mol vs ≈ -126.8 kJ/mol, respectively). In addition, the simulation analyses demonstrated the difference in EGFR binding preference between the drug and tripeptide in which erlotinib was stably bound in the ATP-binding pocket for 4-anilinoquinazoline class of inhibitors, while WFF moved out of that pocket to interact with polar amino acid residues on the αC-helix, activation loop, and substrate-binding region. Our findings suggest preferable interactions of the potential tripeptide on enzyme inhibition that are useful for further development of a new class of inhibitors targeting EGFR-TK.

Design, synthesis and biological evaluation of cinnamamide-quinazoline derivatives as potential EGFR inhibitors to reverse T790M mutation

Gatekeeper T790M mutation in EGFR is the most common factor for acquired resistance. Acrylamide-bearing 4-anilinoquinazoline scaffold are powerful irreversible inhibitors for overcoming resistance. In this work, three series of EGFR inhibitors derived from incorporation of cinnamamide into the quinazoline scaffold were designed and synthesized to reverse resistance resulting from insurgence of T790M mutation. SAR studies revealed that methoxy and acetoxy substitutions on the cinnamic phenyl ring were found to elevate the activity. In particular, compound 7g emerged as the most potent derivative against mutant-type H1975 cells, which exhibited comparable activity to osimertinib (0.95 μM) towards H1975 cells with an IC₅₀ value of 1.22 μM. Kinase inhibition studies indicated that 7g showed excellent inhibitory effect on EGFR^T790M enzyme, which was 11 times more effective than gefitinib. Besides, selectivity index of 7g toward the EGFR^T790M mutant over the EGFR^WT is 2.72, hinting its effect of reducing off-target. Mechanism study indicated that 7g induced apoptosis of H1975 cells and arrest the cell cycle at G2/M phase in a dose-dependent manner. Moreover, 7g could significantly inhibit the expression of p-EGFR and its downstream p-AKT and p-ERK in H1975 cells. Molecular docking was also performed to gain insights into the ligand-binding interactions of 7g inside EGFR^WT and EGFR^T790M binding sites.

Discovery of Potent EGFR Inhibitors With 6-Arylureido-4-anilinoquinazoline Derivatives

According to the classical pharmacophore fusion strategy, a series of 6-arylureido-4-anilinoquinazoline derivatives ( Compounds 7a - t ) were designed, synthesized, and biologically evaluated by the standard CCK-8 method and enzyme inhibition assay. Among the title compounds, Compounds 7a , 7c , 7d , 7f , 7i , 7o , 7p , and 7q exhibited promising anti-proliferative bioactivities, especially Compound 7i , which had excellent antitumor activity against the A549, HT-29, and MCF-7 cell lines (IC₅₀ = 2.25, 1.72, and 2.81 μM, respectively) compared with gefitinib, erlotinib, and sorafenib. In addition, the enzyme activity inhibition assay indicated that the synthesized compounds had sub-micromolar inhibitory levels (IC₅₀, 11.66-867.1 nM), which was consistent with the results of the tumor cell line growth inhibition tests. By comparing the binding mechanisms of Compound 7i (17.32 nM), gefitinib (25.42 nM), and erlotinib (33.25 nM) to the EGFR, it was found that Compound 7i could extend into the effective region with a similar action conformation to that of gefitinib and interact with residues L85, D86, and R127, increasing the binding affinity of Compound 7i to the EGFR. Based on the molecular hybridization strategy, 14 compounds with EGFR inhibitory activity were designed and synthesized, and the action mechanism was explored through computational approaches, providing valuable clues for the research of antitumor agents based on EGFR inhibitors.

Supramolecular nanofibers increase the efficacy of 10-hydroxycamptothecin by enhancing nuclear accumulation and depleting cellular ATP

Poor nuclear delivery and accumulation are the main reasons for the reduced drug efficacy of many anticancer drugs that target DNA or enzymes in the nucleus, and it is a major obstacle to successful cancer therapy. To address this problem, developing practical drug delivery systems for nuclear delivery is urgently needed. Here we develop a supramolecular hydrogel by conjugating the anticancer agent 10-hydroxycamptothecine (HCPT) and macrocyclic polyamine cyclen to a self-assembling peptide. The cyclen fragment possesses nuclear localization and ATP hydrolysis properties, which can provide a synergistic therapeutic effect for cancer treatment. The HCPT-FFFK-cyclen nanofibers showed improved nuclear accumulation and inhibition capacity in cancer cells including drug-resistant cancer cells in vitro. The nanofibers also exhibited favorable ATP consuming ability in vitro. Moreover, the obtained nanomedicine showed enhanced anticancer efficiency and favorable biocompatibility in vivo when administered to mice via tail vein injection. This constructed self-delivery drug system significantly improved the delivery efficiency of the small molecule agents into the nucleus and showed favorable ATP consuming ability, offering new strategies for developing nanomedicines for cancer combination therapy.

Design, synthesis and biological evaluation of sulfamoylphenyl-quinazoline derivatives as potential EGFR/CAIX dual inhibitors

Multi-target, especially dual-target, drug design has become a popular research field for cancer treatment. Development of small molecule dual-target inhibitors through hybridization strategy can provide highly potent and selective anticancer agents. In this study, three series of quinazoline derivatives bearing a benzene-sulfonamide moiety were designed and synthesized as dual EGFR/CAIX inhibitors. All the synthesized compounds were evaluated against epidermoid carcinoma (A431) and non-small cell lung cancer (A549 and H1975) cell lines, which displayed weak to potent anticancer activity. In particular, compound 8v emerged as the most potent derivative against mutant-type H1975 cells, which exhibited comparable activity to osimertinib. Importantly, 8v exhibited stronger anti-proliferative activity than osimertinib against H1975 cells under hypoxic condition. Kinase inhibition studies indicated that 8v showed excellent inhibitory effect on EGFR^T790M enzyme, which was 41 times more effective than gefitinib and almost equal to osimertinib. Mechanism studies revealed that 8v exhibited remarkable CAIX inhibitory effect comparable to acetazolamide and significantly inhibited the expression of p-EGFR as well as its downstream p-AKT and p-ERK in H1975 cells. Notably, 8v was found to inhibit the expression of CAIX and its upstream HIF-1α in H1975 cells under hypoxic condition. Molecular docking was also performed to gain insights into the ligand-binding interactions of 8v inside EGFR^WT, EGFR^T790M and CAIX binding sites.

Recent Advances in the Discovery of Multitargeted Tyrosine Kinase Inhibitors as Anticancer Agents

The treatment of cancer has been one of the most significant challenges for the medical field. Further research on the signal transduction pathway of tumor cells is driving the rapid development of antitumor agents targeting tyrosine kinases. However, most of the currently approved tyrosine kinase inhibitors based on the "single target/single drug" design are becoming less and less effective in the treatment of complex, heterogeneous, and multigenic cancers; this also results in resistance to chemotherapy. In contrast, multitargeted tyrosine kinase inhibitors (MT-TKIs) can effectively block multiple pathways of intracellular signal transduction. Therefore, they have therapeutic advantages over single-targeted inhibitors and have become a hotspot in antitumor drug research in recent years. This minireview summarizes recent advances in the discovery of MT-TKIs based on their chemical structures. In particular, we describe the kinase inhibitory and antitumor activity of promising compounds, as well as their structure - activity relationships (SARs).

Silver mirror films deposited on well plates for SERS detection of multi-analytes: Aiming at 96-well technology

96-Well technology is associated with automated sample preparation and simultaneous analysis based on the low-cost well plate format. To explore the potential applications of 96-well technology in SERS detection, we examined the surface-bound electroless deposition procedure for the preparation of uniform and stable Ag mirror films on polydopamine (PDA)-coated well plates as active-SERS substrates. In the presented procedure, small Ag seeds assembled on PDA coating were employed as the surface-bound catalyst and provided the active sites for electroless Ag deposition. The high-quality Ag mirror films showed high performance in terms of sensitivity, uniformity, reproducibility and stability using rhodamine 6G (R6G) as the probe molecule. A remarkable enhancement factor of 3.41 × 10⁸ was obtained. The relative standard deviations against well-by-well and batch-by-batch reproducibility were less than 5%. The SERS films on well plates were successfully used to quantify the amounts of organic dyes (R6G and malachite green) in environmental water samples and small biological molecules (adenosine triphosphate and adenine) in urine matrix, displaying satisfactory sensitivity, selectivity and recovery. Their limit of detection values were at nanomolar, even picomolar concentration.

Novel quinazoline-based EGFR kinase inhibitors: A review focussing on SAR and molecular docking studies (2015-2019)

The over expression of EGFR has been recognized as the driver mechanism in the occurrence and progression of carcinomas such as lung cancer, breast cancer, pancreatic cancer, etcetera. EGFR receptor was thus established as an important target for the management of solid tumors. The occurrence of resistance caused as a result of mutations in EGFR has presented a formidable challenge in the discovery of novel inhibitors of EGFR. This has resulted in the development of three generations of EGFR TKIs. Newer mutations like C797S cause failure of Osimertinib and other EGFR TKIs belonging to the third-generation caused by the development of resistance. In this review, we have summarized the work done in the last five years to overcome the limitations of currently marketed drugs, giving structural activity relationships of quinazoline-based lead compounds synthesized and tested recently. We have also highlighted the shortcomings of the currently used approaches and have provided guidance for circumventing these limitations. Our review would help medicinal chemists streamline and guide their efforts towards developing novel quinazoline-based EGFR inhibitors.

How Different Substitution Positions of F, Cl Atoms in Benzene Ring of 5-Methylpyrimidine Pyridine Derivatives Affect the Inhibition Ability of EGFRL858R/T790M/C797S Inhibitors: A Molecular Dynamics Simulation Study

Lung cancer is the most frequent cause of cancer-related deaths worldwide, and mutations in the kinase domain of the epidermal growth factor receptor (EGFR) are a common cause of non-small-cell lung cancers, which is a major subtype of lung cancers. Recently, a series of 5-methylpyrimidine-pyridinone derivatives have been designed and synthesized as novel selective inhibitors of EGFR and EGFR mutants. However, the binding-based inhibition mechanism has not yet been determined. In this study, we carried out molecular dynamic simulations and free-energy calculations for EGFR derivatives to fill this gap. Based on the investigation, the three factors that influence the inhibitory effect of inhibitors are as follows: (1) The substitution site of the Cl atom is the main factor influencing the activity through steric effect; (2) The secondary factors are repulsion between the F atom (present in the inhibitor) and Glu762, and the blocking effect of Lys745 on the phenyl ring of the inhibitor. (3) The two factors function synergistically to influence the inhibitory capacity of the inhibitor. The theoretical results of this study can provide further insights that will aid the design of oncogenic EGFR inhibitors with high selectivity.

A peptide–drug hydrogel to enhance the anti-cancer activity of chlorambucil

The CRB–FFF–cyclen could transform into a hydrogel via a heating–cooling process. The resulting hydrogel could be protonated in a tumor environment, which is beneficial for cellular uptake and anti-tumor activity.

Functionalized acupuncture needle as a SERS-active platform for rapid and sensitive determination of adenosine triphosphate

The development of sensitive and rapid methods for analysis and detection of small molecules is highly desirable for medical diagnostics and therapeutics. We report an acupuncture needle functionalized with gold nanoparticles (Au NPs) and a macrocyclic amine (MA) Raman tag as the platform to realize the sensitive detection of adenosine triphosphate (ATP) by surface-enhanced Raman spectroscopy (SERS). The assembled Au NPs with abundant hot spots on the surface of the needle avoids the aggregation of Au NPs and results in a good signal response. Moreover, there is strong combination between ATP and MA through electrostatic adsorption, hydrogen-bonding interactions, and π-π stacking, and as a consequence, this functionalized needle can be used as a SERS platform for detection of ATP (25 nM) through a decrease of the Raman signal of MA resulting from the high chemical affinity of ATP for MA. Specially, the Au NP/MA-functionalized needle is conveniently used to monitor ATP (100 nM) added to serum, and demonstrates great promise in the study and detection of ATP in a complex sample, laying the foundation for SERS applications in complex acupuncture specimens with fast response and simple operation. Graphical abstract.

Accelerating Drug Discovery by Early Protein Drug Target Prediction Based on a Multi-Fingerprint Similarity Search

In this continuing work, we have updated our recently proposed Multi-fingerprint Similarity Search algorithm (MuSSel) by enabling the generation of dominant ionized species at a physiological pH and the exploration of a larger data domain, which included more than half a million high-quality small molecules extracted from the latest release of ChEMBL (version 24.1, at the time of writing). Provided with a high biological assay confidence score, these selected compounds explored up to 2822 protein drug targets. To improve the data accuracy, samples marked as prodrugs or with equivocal biological annotations were not considered. Notably, MuSSel performances were overall improved by using an object-relational database management system based on PostgreSQL. In order to challenge the real effectiveness of MuSSel in predicting relevant therapeutic drug targets, we analyzed a pool of 36 external bioactive compounds published in the Journal of Medicinal Chemistry from October to December 2018. This study demonstrates that the use of highly curated chemical and biological experimental data on one side, and a powerful multi-fingerprint search algorithm on the other, can be of the utmost importance in addressing the fate of newly conceived small molecules, by strongly reducing the attrition of early phases of drug discovery programs.