Discovery of new thieno[3,2-d]pyrimidine derivatives targeting EGFRL858R/T790M NSCLCs by the conformation constrained strategy

Design, synthesis and biological evaluation of novel 4-(thieno[3,2-d]pyrimidin-4-yl)morpholine derivatives as potent antitumor agents

A series of 4-(thieno[3,2-d]pyrimidin-4-yl)morpholine derivatives were designed, synthesized and evaluated for their in vitro inhibitory activities against PI3Kα and antiproliferative activities against PC-3, 22RV1, MDA-MB-231 and MDA-MB-453 cancer cell lines. Inhibitory activities against PI3Kα evaluation indicated that some compounds showed excellent PI3Kα activity in vitro, and IC50 values of eight compounds (17c, 17e, 17f, 17h, 17l, 17m, 17o, 17p) were less than 100 nM. The most promising compound 17f (PI3Kα: IC50 = 0.039 μM) showed remarkable antiproliferative against PC-3, 22RV1, MDA-MB-231 and MDA-MB-453 cell lines with IC50 values of 3.48 μM, 1.06 μM, 2.21 μM and 0.93 μM, respectively. Furthermore, 17f effectively reduced p-PI3K protein expression and inhibited the activation of downstream signaling AKT and mTOR proteins in MDA-MB-453 cells. In addition, 17f induced cell apoptosis by down-regulating the expression levels of anti-apoptotic proteins Bcl-XL and Bcl-2 and up-regulating the expression of anti-apoptotic protein BAX, and in MDA-MB-453 cells. All these results indicated the potential of compound 17f to develop as potent anticancer agent.

Rational design and synthesis of 2,4-dichloro-6-methyl pyrimidine derivatives as potential selective EGFRT790M/L858R inhibitors for the treatment of non-small cell lung cancer

Many patients with non-small cell lung cancer (NSCLC) initially benefit from epidermal growth factor receptor (EGFR) targeted therapy. Unfortunately, varying degrees of resistance or side effects eventually develop. Overcoming and preventing the resistance and side effects of EGFR inhibitors has become a hot topic of research today. Based on the previous studies on AZD-9291, we designed and synthesized two series of 2,4-dichloro-6-methylpyrimidine derivatives, 19 compounds in total, as potential inhibitors of the EGFR kinase. The most promising compound, L-18, showed better inhibitory activity (81.9%) and selectivity against EGFRT790M/L858R kinase. In addition, L-18 showed strong antiproliferative activity against H1975 cells with an IC50 value of 0.65 ± 0.06 μM and no toxicity to normal cells (LO-2). L-18 was able to dose-dependently induce the apoptosis of H1975 cells and produced a cell-cycle-blocking effect, and it can also dose-dependently inhibit the migration and invasion of H1975 cells. L-18 also showed in vivo anticancer efficacy in H1975 cells xenograft mice. We also performed a series of in vivo and in vitro toxicological evaluations of compound L-18, which did not cause obvious injury in mice during administration. These results suggest that L-18 may be a promising drug candidate that warrants further investigation.

Design, Synthesis, and Molecular Docking of Novel Miscellaneous Chalcones as p38α Mitogen-Activated Protein Kinase Inhibitors

New chalcones were synthesized and evaluated to serve as p38-α type of mitogen-activated protein kinase (MAPK) inhibitors. According to the National Cancer Institute, the findings indicated that at a 10 μM dosage, compounds 3a and 6 were the most active among all the compounds examined, with mean growth inhibition% of 94.83 and 58.49, respectively. In 5-dose testing, they showed anticancer activity in the micro-molar range with GI50 in the range of 1.41-46.1 and 2.07-31.3 μM, respectively. Besides, powerful activity, especially against the leukaemia cell lines and good selectivity to cancer cells compared to normal PCS-800-017 with a selectivity index=12.41 and 23.77, respectively. Compounds 3a and 6 inhibited p38α MAPK with IC50 values of 0.1462±0.0063 and 0.4356±0.0189 μM, correspondingly. 3a showed good inhibition for HL-60(TB) cells and induced cell cycle arrest in HL-60(TB) cells at the G2/M phase. Besides, it elevated the total apoptosis by 14.68-fold and increased the caspase-3 level by 3.52-fold compared with doxorubicin, which raised it by 4.30-fold, inducing apoptosis by acting as caspase-dependent inducers. These results suggest that 3a is a promising antiproliferative and p38α MAPK inhibitor, confirmed by molecular docking with high compatibility 3a with the p38α MAPK binding site.

Design, synthesis and biological evaluation of structurally new 4-indolyl quinazoline derivatives as highly potent, selective and orally bioavailable EGFR inhibitors

Targeting the epidermal growth factor receptor (EGFR) has been recognized as an effective strategy for treating non-small-cell lung cancer (NSCLC). Although several representative EGFR inhibitors have been approved for clinical use, it is highly desirable to develop highly potent and selective EGFR inhibitors with novel scaffolds because of the occurrence of acquired resistance after treatment. Here we first demonstrate that the 4-indolyl quinazoline derivatives could potently inhibit EGFR in vitro and in vivo, of which YS-67 effectively and selectively inhibits EGFR[WT] (IC50 = 5.2 nM), EGFR[d746-750] (IC50 = 9.6 nM) and EGFR[L858R] (IC50 = 1.9 nM). The TREEspot™ kinase interaction map further reveals the binding selectivity toward 468 kinases. YS-67 not only potently suppresses p-EGFR and p-AKT, but also effectively inhibits proliferation of A549 (IC50 = 4.1 μM), PC-9 (IC50 = 0.5 μM) and A431 cells (IC50 = 2.1 μM). YS-67 treatment also causes colony formation inhibition, arrests cell cycle progression at G0/G1 phases and induces apoptosis. More importantly, YS-67 is well tolerated in A431 xenograft model after oral administration, showing effective tumor growth suppression and low toxicity. Collectively, YS-67 represents an underexplored scaffold for developing new EGFR inhibitors.

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.

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.

Synthesis and Antitumor Evaluation of Menthone-Derived Pyrimidine-Urea Compounds as Potential PI3K/Akt/mTOR Signaling Pathway Inhibitor

A series of novel menthone derivatives bearing pyrimidine and urea moieties was designed and synthesized to explore more potent natural product-derived antitumor agents. The structures of the target compounds were confirmed by FTIR, NMR, and HRMS. The in vitro antitumor activity was tested by standard methyl thiazolytetrazolium assay and showed that 4i, 4g, 4s, and 4m are the best compounds with IC50 values of 6.04 ± 0.62µM, 3.21 ± 0.67µM, 19.09 ± 0.49µM, and 18.68 ± 1.53µM, against Hela, MGC-803, MCF-7, and A549, respectively. The results of the preliminary action mechanism studies showed that compound 4i, the representative compound, could induce cell apoptosis in Hela cells in a dose-dependent manner and might arrest the cell cycle in the G2/M phase. Furthermore, the results of network pharmacology prediction and Western blot experiments indicated that compound 4i might inhibit Hela cells through inhibit PI3K/Akt/mTOR signaling pathway. The binding modes and the binding sites interactions between compound 4i and the target proteins were predicted preliminarily by the molecular docking method.

Comparative differential cytotoxicity of clinically used SERMs in human cancer lines of different origin and its predictive molecular docking studies of key target genes involved in cancer progression and treatment responses

SERMS like Tamoxifene, 5-hydroxy tamoxifene, raloxifene and endoxifene has been used for the treatment of hormonal imbalances and dependent cancers owing to their action via Estrogen receptors as in the treatment of estrogen sensitive breast cancers. Due to the adverse side effects, modifications and development of the existing or newer SERMS has always been of immense interest. Ormeloxifene, a SERM molecule manufactured by HLL Lifecare Ltd, India as birth control under the trade names Saheli, Novex, and Novex-DS which is also investigated against mastalgia, fibro-adenoma and abnormal uterine bleeding. Anti-cancer effects have been reported in estrogen dependent and independent cancers which shows its wide scope to be implemented in cancer therapy. Current investigation is a comprehensive effort to find the cytotoxic potential of Ormeloxifene in comparison with clinically used four SERMS in twenty six cancer cell lines of different origin using Adriamycin as positive control. Also the computational studies pertaining to selected target/ligand with respect to tumor progression, development, treatment responses and apoptosis. The studies proved effective cytotoxicity of Ormeloxifene on cancer cell lines with lower TGI, GI50 and LC50 values which are significantly comparable. Also the in silico studies proved that the docking score of the compound suggests the interaction of the compound which could tightly regulate key target genes controlling cancer like ER, EGFR kinase, EGFR-cSRC, HDAC-2, PARP-1 and BRAF. This study brings out the superior efficacy of Ormeloxifene compared to other SERMS with proven safety profile to be repositioned as an anti-cancer drug to treat diverse cancer types.

New Compounds with Bioisosteric Replacement of Classic Choline Kinase Inhibitors Show Potent Antiplasmodial Activity

In the fight against Malaria, new strategies need to be developed to avoid resistance of the parasite to pharmaceutics and other prevention barriers. Recently, a Host Directed Therapy approach based on the suppression of the starting materials uptake from the host by the parasite has provided excellent results. In this article, we propose the synthesis of bioisosteric compounds that are capable of inhibiting Plasmodium falciparum Choline Kinase and therefore to reduce choline uptake, which is essential for the development of the parasite. Of the 41 bioisosteric compounds reported herein, none showed any influence of the linker on the antimalarial and enzyme inhibitory activity, whereas an effect of the type of cationic heads used could be observed. SARs determined that the thienopyrimidine substituted in 4 by a pyrrolidine is the best scaffold, independently of the chosen linker. The decrease in lipophilicity seems to improve the antimalarial activity but to cause an opposite effect on the inhibition of the enzyme. While potent compounds with similar good inhibitory values have been related to the proposed mechanism of action, some of them still show discrepancies and further studies are needed to determine their specific molecular target.

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.

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.

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.

Toward structure-based drug design against the epidermal growth factor receptor (EGFR)

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Structural variations in EGFR should not be ignored in structure-based drug design.

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Main variations involve inward and outward folding of C-helix in the kinase N-lobe.

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Origins of variations are mutations and drug R-groups but not the drug core.

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Comparative modeling, fitting and clustering are imperative steps in EGFR drug design.

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Alternatively, volume and shape of binding site can be used to filter ligands against structures.

Most of the available crystal structures of epidermal growth factor receptor (EGFR) kinase domain, bound to drug inhibitors, originated from ligand-based drug design studies. Here, we used variations in 110 crystal structures to assemble eight distinct families highlighting the C-helix orientation in the N-lobe of the EGFR kinase domain. The families shared similar mutational profiles and similarity in the ligand R-groups (chemical composition, geometry, and charge) facing the C-helix, mutation sites, and DFG domain. For structure-based drug design, we recommend a systematic decision-making process for choice of template, guided by appropriate pairwise fitting and clustering before the molecular docking step. Alternatively, the binding site shape/volume can be used to filter and select the compound libraries.