The new opportunities in medicinal chemistry of fourth-generation EGFR inhibitors to overcome C797S mutation

Clinical Practice Recommendations for the Use of Next-Generation Sequencing in Patients with Solid Cancer: A Joint Report from KSMO and KSP

In recent years, next-generation sequencing (NGS)-based genetic testing has become crucial in cancer care. While its primary objective is to identify actionable genetic alterations to guide treatment decisions, its scope has broadened to encompass aiding in pathological diagnosis and exploring resistance mechanisms. With the ongoing expansion in NGS application and reliance, a compelling necessity arises for expert consensus on its application in solid cancers. To address this demand, the forthcoming recommendations not only provide pragmatic guidance for the clinical use of NGS but also systematically classify actionable genes based on specific cancer types. Additionally, these recommendations will incorporate expert perspectives on crucial biomarkers, ensuring informed decisions regarding circulating tumor DNA panel testing.

Clinical practice recommendations for the use of next-generation sequencing in patients with solid cancer: a joint report from KSMO and KSP

In recent years, next-generation sequencing (NGS)-based genetic testing has become crucial in cancer care. While its primary objective is to identify actionable genetic alterations to guide treatment decisions, its scope has broadened to encompass aiding in pathological diagnosis and exploring resistance mechanisms. With the ongoing expansion in NGS application and reliance, a compelling necessity arises for expert consensus on its application in solid cancers. To address this demand, the forthcoming recommendations not only provide pragmatic guidance for the clinical use of NGS but also systematically classify actionable genes based on specific cancer types. Additionally, these recommendations will incorporate expert perspectives on crucial biomarkers, ensuring informed decisions regarding circulating tumor DNA panel testing.

Custom-Designed Probes for the Accurate Determination of Epidermal Growth Factor Receptor Mutations and Their Allelic Configuration

The identification of single nucleotide polymorphisms (SNPs) is of paramount importance for disease diagnosis and clinical prognostication. In the context of nonsmall cell lung cancer (NSCLC), the emergence of resistance mutations, exemplified by the epidermal growth factor receptor (EGFR) T790 M and C797S, is intricately linked to the therapeutic efficacy of EGFR tyrosine kinase inhibitors (EGFR-TKIs). Herein, a highly efficient and specific SNP detection platform for T790 M and C797S mutations has been engineered through the integration of an asymmetric polymerase chain reaction (PCR) and an ingeniously tailored four-way junction (4WJ) probe. Notably, a molecular beacon (MB) probe was judiciously designed to discern the allelic configuration of these mutations. The administration of first- and third-generation EGFR-TKIs demonstrates therapeutic efficacy solely when the mutations are in the trans configuration, characterized by a low fluorescence signal. In contrast, significant fluorescence by the MB probe is indicative of the C797S mutation being in a cis arrangement with T790M, thereby rendering the cells refractory to the therapeutic interventions of both first- and third-generation EGFR-TKIs. The assay is capable of concurrently detecting two point-mutations and ascertaining their allelic positions in a single test within 1.5 h, enhancing both efficiency and simplicity. It also exhibits high accuracy in the identification of clinical samples, offering promising implications for therapeutic guidelines. By enabling tailored treatment plans based on specific genetic profiles, our approach not only advances the precision of NSCLC treatment strategies but also marks a significant contribution to personalized medicine.

Design, synthesis, and evaluation of antitumor activity of Mobocertinib derivatives, a third-generation EGFR inhibitor

Mobocertinib, as a structural analog of the third generation TKI Osimertinib, can selectively act on the EGFRex20 mutation. We have structurally modified Mobocertinib to obtain new EGFR inhibitors. In this paper, we chose Mobocertinib as a lead compound for structural modification to investigate the effect of Mobocertinib derivatives on EGFRT790M mutation. We designed and synthesized 63 Mobocertinib derivatives by structural modification using the structural similarity strategy and the bioelectronic isoarrangement principle. Then, we evaluated the in vitro antitumor activity of the 63 Mobocertinib derivatives and found that the IC50 of compound H-13 against EGFRL858R/T790M mutated H1975 cells was 3.91 μM, and in further kinase activity evaluation, the IC50 of H-13 against EGFRL858R/T790M kinase was 395.2 nM. In addition, the preferred compound H-13 was able to promote apoptosis of H1975 tumor cells and block the proliferation of H1975 cells in the G0/G1 phase; meanwhile, it was able to significantly inhibit the migratory ability of H1975 tumor cells and inhibit the growth of H1975 cells in a time-concentration-dependent manner. In the in vivo anti-tumor activity study, the preferred compound H-13 had no obvious toxicity to normal mice, and the tumor inhibition effect on H1975 cell-loaded nude mice was close to that of Mobocertinib. Finally, molecular dynamics simulations showed that the binding energy between compound H-13 and 3IKA protein was calculated to be -162.417 ± 14.559 kJ/mol. In summary, the preferred compound H-13 can be a potential third-generation EGFR inhibitor.

Harnessing molecular hybridization approach to discover novel quinoline EGFR-TK inhibitors for cancer treatment

Aim: Using molecular hybridization approach, novel 18 quinoline derivatives (6a-11) were designed and synthesized as EGFR-TK inhibitors. Materials & methods: The antiproliferative activity was assessed against breast (MCF-7), leukemia (HL-60) and lung (A549) cancer cell lines. Moreover, the most active quinoline derivatives (6d and 8b) were further investigated for their potential as EGFR-TK inhibitors. In addition, cell cycle analysis and apoptosis induction activity were conducted. Results: A considerable cytotoxic activity was attained with IC50 values spanning from 0.06 to 1.12 μM. Besides, the quinoline derivatives 6d and 8b displayed potent inhibitory activity against EFGR with IC50 values of 0.18 and 0.08 μM, respectively. Conclusion: Accordingly, the afforded quinoline derivatives can be used as promising lead anticancer candidates for future optimization.

Impact of sequential (first- to third-generation) EGFR-TKI treatment on corrected QT interval in NSCLC patients

Objective

To evaluate the impact of sequential (first- to third-generation) epidermal growth factor receptor tyrosine kinase inhibitor (EGFR-TKI) treatment on top-corrected QT interval (top-QTc) in non-small cell lung cancer (NSCLC) patients.

Methods

We retrospectively reviewed the medical records of NSCLC patients undergoing sequential EGFR-TKI treatment at Shanghai Chest Hospital between October 2016 and August 2021. The heart rate (HR), top-QT interval, and top-QTc of their ECGs were extracted from the institutional database and analyzed. Logistic regression was performed to identify predictors for top-QTc prolongation.

Results

Overall, 228 patients were enrolled. Compared with baseline (median, 368 ms, same below), both first-generation (376 ms vs. 368 ms, p < 0.001) and sequential third-generation EGFR-TKIs (376 ms vs. 368 ms, p = 0.002) prolonged top-QT interval to a similar extent (p = 0.635). Top-QTc (438 ms vs. 423 ms, p < 0.001) and HR (81 bpm vs.79 bpm, p = 0.008) increased after first-generation EGFR-TKI treatment. Further top-QTc prolongation (453 ms vs. 438 ms, p < 0.001) and HR increase (88 bpm vs. 81 bpm, p < 0.001) occurred after treatment advanced. Notably, as HR elevated during treatment, top-QT interval paradoxically increased rather than decreased, and the top-QTc increased rather than slightly fluctuated. Moreover, such phenomena were more significant after treatment advanced. After adjusting for confounding factors, pericardial effusion and lower serum potassium levels were independent predictors of additional QTc prolongation during sequential third-generation EGFR-TKI treatment.

Conclusion

First-generation EGFR-TKI could prolong top-QTc, and sequential third-generation EGFR-TKI induced further prolongation. Top-QT interval paradoxically increased and top-QTc significantly increased as HR elevated, which was more significant after sequential EGFR-TKI treatment. Pericardial effusion and lower serum potassium levels were independent predictors of additional QTc prolongation after sequential EGFR-TKI treatment.

Late-stage modification of complex drug: Base-controlled Pd-catalyzed regioselective synthesis and bioactivity of arylated osimertinibs

Achieving regioselective synthesis in complex molecules with multiple reactive sites remains a tremendous challenge in synthetic chemistry. Regiodivergent palladium-catalyzed C─H arylation of complex antitumor drug osimertinib with various aryl bromides via the late-stage functionalization strategy was demonstrated here. This reaction displayed a switch in regioselectivity under complete base control. Potassium carbonate (K2CO3) promoted the arylation of acrylamide terminal C(sp2)-H, affording 34 derivatives. Conversely, sodium tert-butoxide (t-BuONa) mediated the aryl C(sp2)-H arylation of the indole C2 position, providing 27 derivatives. The derivative 3r containing a 3-fluorophenyl group at the indole C2 position demonstrated similar inhibition of EGFRT790M/L858R and superior antiproliferative activity in H1975 cells compared to osimertinib, as well as similar antiproliferative activity in A549 cells and antitumor efficacy in xenograft mouse model bearing H1975 cells. This approach provides a "one substrate-multi reactions-multiple products" strategy for the structural modification of complex drug molecules, creating more opportunities for the fast screening of pharmaceutical molecules.

Design, synthesis, and mechanistic insight of novel imidazolones as potential EGFR inhibitors and apoptosis inducers

As regards to the structural analysis and optimization of diverse potential EGFR inhibitors, two series of imidazolyl-2-cyanoprop-2-enimidothioates and ethyl imidazolylthiomethylacrylates were designed and constructed as potential EGFR suppressors. The cytotoxic effect of the prepared derivatives was assessed toward hepatic, breast, and prostate cancerous cells (Hep-G2, MCF-7, and PC-3). Three derivatives 3d, 3e, and 3f presented potent antiproliferative activity and selectivity against the examined tumor cells showing IC50 values at low micromolar levels. Hence, successive biological assays were applied to determine the probable mechanism of action of the new compounds. They exhibited significant EGFR suppression with an IC50 range of 0.137-0.507 µM. The most effective EGFR inhibitor 3f arrested the MCF-7 cell cycle at the S phase by inducing the apoptotic pathway that was confirmed via increasing the expression of Caspases 8, 9, and Bax, which are associated with Bcl-2 decline. Additionally, molecular docking displayed a distinctive interaction between 3f and EGFR binding pocket. Overall, this work introduces some novel imidazolyl-2-cyanoprop-2-enimidothioates and ethyl imidazolylthiomethylacrylates as potential cytotoxic and EGFR inhibitors that deserve further research in tumor therapy.

Design, synthesis and antitumor activity of 4-arylamine substituted pyrimidine derivatives as noncovalent EGFR inhibitors overcoming C797S mutation

Clinical researches have shown that epidermal growth factor receptor (EGFR) is a key target for treatment of non-small cell lung cancer (NSCLC). Many EGFR inhibitors were successfully developed as ani-tumor drugs to treat NSCLC patients. Unfortunately, drug resistances were found in clinic. To overcome C797S mutation in EGFR, a novel series of 4-arylamine substituted pyrimidine derivatives were designed and synthesized under the principle of structure-based drug design. Interestingly, compounds 6e and 9i demonstrated the best anti-proliferative activity against A549, NCI-H1975, and HCC827 cells. In particular, the IC50 values against HCC827 cells reached to 24.6 nM and 31.6 nM, which were much lower than human normal cells 2BS and LO2. Furthermore, compounds 6e and 9i showed extraordinary activity against EGFR19del/T790M/C797S (IC50 = 16.06 nM and 37.95 nM) and EGFRL858R/T790M/C797S (IC50 = 11.81 nM and 26.68 nM), which were potent than Osimertinib (IC50 = 52.28 nM and 157.60 nM). Further studies have shown that compounds 6e and 9i could pertain inhibition of HCC827 colony formation, and arrest HCC827 cells at G2/M phase. Moreover, the most promising compound 6e could inhibit the migration of HCC827 cells, induce HCC827 cells apoptosis, and significantly inhibit the phosphorylation of EGFR, AKT and Erk1/2. In vivo xenograft mouse model with HCC827 cells, compound 6e resulted in remarkable tumor regression without obvious toxicity. In addition, molecular docking studies suggested that compound 6e could firmly combine with T790M-mutant, T790 M/C797S-mutant, and L858R/T790 M/C797S-mutant EGFR kinases as ATP-competitive inhibitor.

Design, synthesis, and biological evaluation of 4-(2-fluorophenoxy)-7-methoxyquinazoline derivatives as dual EGFR/c-Met inhibitors for the treatment of NSCLC

In non-small cell lung cancer (NSCLC) treatment, aberrant expression of c-mesenchymal-epithelial transition factor (c-Met) has been identified as a driving factor in epidermal growth factor receptor tyrosine kinase inhibitor (EGFR-TKI) resistance. Unfortunately, none of the EGFR/c-Met dual-target inhibitors have successfully passed clinical trials. Hence, based on molecular docking analysis and combination principles of EGFR and c-Met inhibitors, three series of 4-(2-fluorophenoxy)-7-methoxyquinazoline derivatives as new EGFR/c-Met inhibitors were designed, synthesized, and evaluated for their biological activities. Among these compounds, TS-41 displayed the best inhibitory activity against EGFRL858R and c-Met kinases, with an IC50 value of 68.1 nM and 0.26 nM respectively. Moreover, it also showed excellent inhibitory activity on three NSCLC cell lines A549-P, H1975 and PC-9 with IC50 values ranging from 1.48 to 2.76 μM. Flow cytometry assays demonstrated that TS-41 induced apoptosis and cell cycle arrest of A549-P cells in a concentration-dependent manner, corresponding to JC-1 staining assay results. Western blot analysis revealed that TS-41 significantly downregulated the phosphorylation of EGFR, c-Met, and downstream AKT at molecular level. Importantly, TS-41 exhibited potent in vivo anticancer efficacy in an A549-P-bearing allograft nude mouse model at a dose of 60 mg/kg with a tumor growth inhibition rate of 55.3 % compared with Afatinib (46.4 %), as well as low hemolytic toxicity and organ toxicity. Molecular docking results showed that TS-41 was well embedded into the cavity of EGFR (PDB: 5GMP) and c-Met (PDB: 3LQ8) proteins, respectively. In summary, TS-41 is a high-efficiency and low-toxicity EGFR/c-Met inhibitor for the treatment of NSCLC and is worthy of further exploration.

Discovery of Novel Fourth-Generation EGFR Inhibitors to Overcome C797S-Mediated Resistance

Epidermal growth factor receptor (EGFR)-activating mutation is an important oncogenic driver of nonsmall cell lung cancer (NSCLC) patients. Osimertinib has been the first-line treatment for EGFR-mutated NSCLC. However, the tertiary C797S mutation leads to Osimertinib resistance by blocking the covalent binding of Cys797 to Osimertinib. To date, there are no approved inhibitors for the treatment of Osimertinib resistance. Herein, we identified a novel lead compound S8 targeting EGFRL858R/T790M/C797S by structure-based virtual screening and synthesized a series of novel compounds. Representative compound C34 showed potent inhibitory activity against EGFRL858R/T790M/C797S with an IC50 of 5.1 nM and significantly inhibited the proliferation of the H1975-TM cell line harboring EGFRL858R/T790M/C797S with an IC50 of 0.05 μM. Additionally, compound C34 demonstrated good pharmacokinetic properties with an oral bioavailability of 30.72% and significantly inhibited tumor growth in the H1975-TM xenograft tumor model. This study provides a novel thiazole derivative as an EGFR inhibitor to overcome C797S-mediated resistance.

CODD-Pred: A Web Server for Efficient Target Identification and Bioactivity Prediction of Small Molecules

Target identification and bioactivity prediction are critical steps in the drug discovery process. Here we introduce CODD-Pred (COmprehensive Drug Design Predictor), an online web server with well-curated data sets from the GOSTAR database, which is designed with a dual purpose of predicting potential protein drug targets and computing bioactivity values of small molecules. We first designed a double molecular graph perception (DMGP) framework for target prediction based on a large library of 646 498 small molecules interacting with 640 human targets. The framework achieved a top-5 accuracy of over 80% for hitting at least one target on both external validation sets. Additionally, its performance on the external validation set comprising 200 molecules surpassed that of four existing target prediction servers. Second, we collected 56 targets closely related to the occurrence and development of cancer, metabolic diseases, and inflammatory immune diseases and developed a multi-model self-validation activity prediction (MSAP) framework that enables accurate bioactivity quantification predictions for small-molecule ligands of these 56 targets. CODD-Pred is a handy tool for rapid evaluation and optimization of small molecules with specific target activity. CODD-Pred is freely accessible at http://codd.iddd.group/.

Targeted Strategies for Degradation of Key Transmembrane Proteins in Cancer

Targeted protein degradation is an attractive technology for cancer treatment due to its ability to overcome the unpredictability of the small molecule inhibitors that cause resistance mutations. In recent years, various targeted protein degradation strategies have been developed based on the ubiquitin-proteasome system in the cytoplasm or the autophagy-lysosomal system during endocytosis. In this review, we describe and compare technologies for the targeted inhibition and targeted degradation of the epidermal growth factor receptor (EGFR), one of the major proteins responsible for the onset and progression of many types of cancer. In addition, we develop an alternative strategy, called alloAUTO, based on the binding of new heterocyclic compounds to an allosteric site located in close proximity to the EGFR catalytic site. These compounds cause the targeted degradation of the transmembrane receptor, simultaneously activating both systems of protein degradation in cells. Damage to the EGFR signaling pathways promotes the inactivation of Bim sensor protein phosphorylation, which leads to the disintegration of the cytoskeleton, followed by the detachment of cancer cells from the extracellular matrix, and, ultimately, to cancer cell death. This hallmark of targeted cancer cell death suggests an advantage over other targeted protein degradation strategies, namely, the fewer cancer cells that survive mean fewer chemotherapy-resistant mutants appear.

An outlook of docking analysis and structure-activity relationship of pyrimidine-based analogues as EGFR inhibitors against non-small cell lung cancer (NSCLC)

Almost 80% of lung cancer diagnoses each year correspond to non-small cell lung cancer (NSCLC). The percentage of NSCLC with EGFR overexpression ranges from 40% to 89%, with squamous tumors showing the greatest rates (89%) and adenocarcinomas showing the lowest rates (41%). Therefore, in NSCLC therapy, blocking the EGFR-driven pathway by inhibiting the intracellular tyrosine kinase domain of EGFR has exhibited significant improvement. In this view, several small molecules particularly pyrimidine/fused pyrimidine scaffolds were intended for molecular hybridization to develop EGFR-TK inhibitors. However, the associated limitation such as resistance and genetic mutation along with adverse effects, constrained the long-term treatment and effectiveness of such medication. Therefore, in recent years, pyrimidine derivatives were uncovered as potential EGFR TKIs. The present review summarised the research progress of EGFR TKIs to dazed structure-activity relationship, biological evaluation, and comparative docking studies of pyrimidine compounds. We have added the comparative docking analysis followed by the molecular simulation study against the four different PDBs of EGFR to strengthen the already existing research. Docking analysis unfolded that compound 14 resulted as noticeable with all different PDB and managed to interact with some of the crucial amino acid residues. From a future perspective, researchers must develop a more selective inhibitor, that can selectively target the mutation. Our review will support medicinal chemists in the direction of the development of novel pyrimidine-based EGFR TKIs.Communicated by Ramaswamy H. Sarma.

Protein posttranslational modifications in health and diseases: Functions, regulatory mechanisms, and therapeutic implications

Protein posttranslational modifications (PTMs) refer to the breaking or generation of covalent bonds on the backbones or amino acid side chains of proteins and expand the diversity of proteins, which provides the basis for the emergence of organismal complexity. To date, more than 650 types of protein modifications, such as the most well-known phosphorylation, ubiquitination, glycosylation, methylation, SUMOylation, short-chain and long-chain acylation modifications, redox modifications, and irreversible modifications, have been described, and the inventory is still increasing. By changing the protein conformation, localization, activity, stability, charges, and interactions with other biomolecules, PTMs ultimately alter the phenotypes and biological processes of cells. The homeostasis of protein modifications is important to human health. Abnormal PTMs may cause changes in protein properties and loss of protein functions, which are closely related to the occurrence and development of various diseases. In this review, we systematically introduce the characteristics, regulatory mechanisms, and functions of various PTMs in health and diseases. In addition, the therapeutic prospects in various diseases by targeting PTMs and associated regulatory enzymes are also summarized. This work will deepen the understanding of protein modifications in health and diseases and promote the discovery of diagnostic and prognostic markers and drug targets for diseases.

Addressing the Osimertinib Resistance Mutation EGFR-L858R/C797S with Reversible Aminopyrimidines

Drug resistance mutations emerging during the treatment of non-small cell lung cancer (NSCLC) with epidermal growth factor receptor (EGFR) inhibitors represent a major challenge in personalized cancer treatment and require constant development of new inhibitors. For the covalent irreversible EGFR inhibitor osimertinib, the predominant resistance mechanism is the acquired C797S mutation, which abolishes the covalent anchor point and thus results in a dramatic loss in potency. In this study, we present next-generation reversible EGFR inhibitors with the potential to overcome this EGFR-C797S resistance mutation. For this, we combined the reversible methylindole-aminopyrimidine scaffold known from osimertinib with the affinity driving isopropyl ester of mobocertinib. By occupying the hydrophobic back pocket, we were able to generate reversible inhibitors with subnanomolar activity against EGFR-L858R/C797S and EGFR-L858R/T790M/C797S with cellular activity on EGFR-L858R/C797S dependent Ba/F3 cells. Additionally, we were able to resolve cocrystal structures of these reversible aminopyrimidines, which will guide further inhibitor design toward C797S-mutated EGFR.

Therapeutic potential and limitations of curcumin as antimetastatic agent

Treatment of metastatic cancer is one of the biggest challenges in anticancer therapy. Curcumin is interesting nature polyphenolic compound with unique biological and medicinal effects, including repression of metastases. High impact studies imply that curcumin can modulate the immune system, independently target various metastatic signalling pathways, and repress migration and invasiveness of cancer cells. This review discusses the potential of curcumin as an antimetastatic agent and describes potential mechanisms of its antimetastatic activity. In addition, possible strategies (curcumin formulation, optimization of the method of administration and modification of its structure motif) to overcome its limitation such as low solubility and bioactivity are also presented. These strategies are discussed in the context of clinical trials and relevant biological studies.

Mechanistic Modeling of Lys745 Sulfonylation in EGFR C797S Reveals Chemical Determinants for Inhibitor Activity and Discriminates Reversible from Irreversible Agents

Targeted covalent inhibitors hold promise for drug discovery, particularly for kinases. Targeting the catalytic lysine of epidermal growth factor receptor (EGFR) has attracted attention as a new strategy to overcome resistance due to the emergence of C797S mutation. Sulfonyl fluoride derivatives able to inhibit EGFR^{L858R/T790M/C797S} by sulfonylation of Lys745 have been reported. However, atomistic details of this process are still poorly understood. Here, we describe the mechanism of inhibition of an innovative class of compounds that covalently engage the catalytic lysine of EGFR, through a sulfur(VI) fluoride exchange (SuFEx) process, with the help of hybrid quantum mechanics/molecular mechanics (QM/MM) and path collective variables (PCVs) approaches. Our simulations identify the chemical determinants accounting for the irreversible activity of agents targeting Lys745 and provide hints for the further optimization of sulfonyl fluoride agents.

Recent Advances in Boosting EGFR Tyrosine Kinase Inhibitors-Based Cancer Therapy

Epidermal growth factor receptor (EGFR) plays a key role in signal transduction pathways associated with cell proliferation, growth, and survival. Its overexpression and aberrant activation in malignancy correlate with poor prognosis and short survival. Targeting inhibition of EGFR by small-molecular tyrosine kinase inhibitors (TKIs) is emerging as an important treatment model besides of chemotherapy, greatly reshaping the landscape of cancer therapy. However, they are still challenged by the off-targeted toxicity, relatively limited cancer types, and drug resistance after long-term therapy. In this review, we summarize the recent progress of oral, pulmonary, and injectable drug delivery systems for enhanced and targeting TKI delivery to tumors and reduced side effects. Importantly, EGFR-TKI-based combination therapies not only greatly broaden the applicable cancer types of EGFR-TKI but also significantly improve the anticancer effect. The mechanisms of TKI resistance are summarized, and current strategies to overcome TKI resistance as well as the application of TKI in reversing chemotherapy resistance are discussed. Finally, we provide a perspective on the future research of EGFR-TKI-based cancer therapy.

Design, synthesis and antitumor activity of novel thiophene- triazine derivatives bearing arylurea unit as potent PI3K/mTOR inhibitorss

In this article, we designed and synthesized a series of novel thiophene-triazine derivatives bearing arylurea unit as potent dual PI3K/mTOR inhibitors. The cytotoxicity of all the target compounds were evaluated against nine cancer cell lines (breast cancer cell line MCF-7, lung cancer cell lines A549, NCI-H460, H2228 and H1975, cervical cancer cell lines Hela and Hela-MDR, ovarian cancer cell lines Ovcar-2 and glioma U87MG) and the kinase inhibitory activity against PI3K/mTOR kinases was also tested. The results demonstrated that most of the target compounds exhibited moderate to excellent activity and high selectivity against one or more cancer cell lines. Among them, seven compounds displayed better activity than lead compound GDC-0941. The inhibitory activity of the most promising compound on nine cancer cell lines was 302.5 times better than that of GDC-0941 with the IC₅₀ values as low as 0.008 ± 0.002 μM, and the inhibitory activity against PI3Kα and mTOR kinase was excellent, with the IC₅₀ values of 177.41 and 12.24 nM, respectively, indicating that it was a potential dual PI3Kα/mTOR inhibitor. The Structure-Activity Relationships (SARs) indicated that the introduction of the arylurea group significantly improved the cellular and kinase activities of the target compounds. Moreover, the results of toxicity and hemolysis experiments demonstrated that the most promising compound had low toxicity and good safety. The results of PCR assay and molecular docking modes showed that it was a potential PI3K/mTOR inhibitor, which was worthy of further study.

Discovery of Putative Dual Inhibitor of Tubulin and EGFR by Phenotypic Approach on LASSBio-1586 Homologs

Combretastatin A-4 (CA-4, 1) is an antimicrotubule agent used as a prototype for the design of several synthetic analogues with anti-tubulin activity, such as LASSBio-1586 (2). A series of branched and unbranched homologs of the lead-compound 2, and vinyl, ethinyl and benzyl analogues, were designed and synthesized. A comparison between the cytotoxic effect of these homologs and 2 on different human tumor cell lines was performed from a cell viability study using MTT with 48 h and 72 h incubations. In general, the compounds were less potent than CA-4, showing CC50 values ranging from 0.030 μM to 7.53 μM (MTT at 72 h) and 0.096 μM to 8.768 μM (MTT at 48 h). The antimitotic effect of the target compounds was demonstrated by cell cycle analysis through flow cytometry, and the cellular mechanism of cytotoxicity was determined by immunofluorescence. While the benzyl homolog 10 (LASSBio-2070) was shown to be a microtubule stabilizer, the lead-compound 2 (LASSBio-1586) and the methylated homolog 3 (LASSBio-1735) had microtubule destabilizing behavior. Molecular docking studies were performed on tubulin protein to investigate their binding mode on colchicine and taxane domain. Surprisingly, the benzyl homolog 10 was able to modulate EGFR phosphorylate activity in a phenotypic model. These data suggest LASSBio-2070 (10) as a putative dual inhibitor of tubulin and EGFR. Its binding mode with EGFR was determined by molecular docking and may be useful in lead-optimization initiatives.

Novel anilinopyrimidine derivatives as potential EGFRT790M/C797S Inhibitors: Design, Synthesis, biological activity study

EGFR^T790M/C797S is an important target for the development of new generation of EGFR kinase inhibitors without drug resistance. In this work, a series of anilinopyrimidine derivatives that targeting EGFR^T790M/C797S were designed, synthesized, and evaluated in vitro for the inhibitory effect on triple mutations kinases and cell lines. Based on the pharmacology data, the anilinopyrimidine derivatives showed high inhibitory activity on triple mutations kinases (EGFR^{del 18/T790M/C797S} and EGFR^{L858R/T790M/C797S}) as well as the cell line Ba/F3 with highly expression of EGFR^{del 18/T790M/C797S}. In addition, the anilinopyrimidine derivatives had a more than 50-fold selectivity towards EGFR^{del 18/T790M/C797S} as compared with EGFR^WT. In vivo antitumor activity test also indicated that 8j had good pharmacokinetic parameters, low toxicity and better inhibitory activity. Overall, the anilinopyrimidine derivatives could be regarded as promising candidates for the further development of novel EGFR^T790M/C797S inhibitors for clinical application.

Recent advances in the development of EGFR degraders: PROTACs and LYTACs

Epidermal Growth Factor Receptor (EGFR), a transmembrane tyrosine kinase receptor, belongs to the ErbB receptor family, also known as HER1 or ErbB1. Its abnormal expression and activation contribute to tumor development, especially in non-small cell lung cancer (NCSCL). The first-to fourth-generation inhibitors of EGFR were developed to solve mutations at different sites, but the problem of resistance has not been fundamentally addressed. Targeted protein degradation (TPD) technologies, including PROteolysis Targeting Chimeras (PROTACs) and LYsosome Targeting Chimeras (LYTACs), take advantages of protein destruction mechanism in cells, which make up for shortcomings of traditional small molecular occupancy-driven inhibitors. PROTACs based heterobifunctional EGFR degraders were recently developed by making use of wild-type (WT) and mutated EGFR inhibitors. These degraders compared with EGFR inhibitors showed better efficiency in their cellular potency, inhibition and toxicity profiles. In this review, we first introduce the structural properties of EGFR, the inhibitors that have been developed against WT/mutated EGFR, and then mainly focuses on the recent advances of EGFR-targeting degraders along with its limitations and unlimited prospects.

Two case reports of non-small cell lung cancer patients harboring acquired EGFR T790M-cis-C797S benefit from immune checkpoint inhibitor combined with platinum-based doublet chemotherapy

Background

Acquired resistance is inevitable in non-small cell lung cancer (NSCLC) patients treated with epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs). The emergence of EGFR exon 20 C797S is one of the major resistance mechanisms to osimertinib as a third-generation EGFR-TKI. To date, there is no standard of care for NSCLC patients after acquiring EGFR C797S. Immune checkpoint inhibitors (ICIs) have revolutionized the treatment of various types of cancers in the last decade. Whether NSCLC patients with acquired EGFR C797S could benefit from ICIs remains elusive.

Case Description

Herein, we reported two cases of EGFR-mutant NSCLC patients who acquired a tertiary EGFR mutation C797S benefited from ICIs. A 28-year-old woman presented with anepithymia and nausea. Chest computed tomography (CT) revealed a mass in the right lung. She was diagnosed with stage IV lung adenocarcinoma (LUAD) with EGFR exon 19 deletion (19del) based on imaging and next-generation sequencing (NGS) findings. She received icotinib followed by osimertinib, then acquired EGFR T790M-cis-C797S. She had low tumor mutation burden (TMB) and achieved partial response (PR) to a programmed cell death-1 (PD-1) inhibitor sintilimab combined with platinum-based doublet chemotherapy as late-line treatment lasting more than 5 months. A 66-year-old man complained with chest tightness, hemoptysis, and back pain. CT scans revealed a mass in the right lung and metastases to the bilateral lungs, liver, adrenal gland, mediastinal lymph nodes, and bone. He was also diagnosed with EGFR 19del-positive LUAD and treated with icotinib followed by osimertinib. He also acquired EGFR T790M-cis-C797S. The patient had low TMB also and benefited from a PD-1 inhibitor camrelizumab combined with platinum-based doublet chemotherapy as late-line treatment with a progression-free survival (PFS) of 8 months. Two cases had no treatment-related adverse events leading to discontinuation of PD-1 inhibitors.

Conclusions

Our study provides the first clinical evidence that ICIs combined with platinum-based doublet chemotherapy may be effective treatment options for overcoming resistance mediated by EGFR T790M-cis-C797S. Clinical trials are needed to evaluate the efficacy and safety of PD-1 inhibitors in the treatment of NSCLC patients harboring EGFR T790M-cis-C797S.

HJM-561, a potent, selective and orally bioavailable EGFR PROTAC that overcomes osimertinib-resistant EGFR triple mutations

The epidermal growth factor receptor (EGFR) C797S mutation is the most common on-target resistance mechanism to osimertinib in patients with advanced non-small-cell lung cancer (NSCLC). Currently there are no effective treatment options for NSCLC patients harboring EGFR C797S triple mutants (Del19/T790M/C797S and L858R/T790M/C797S). Herein, we report an orally bioavailable EGFR PROTAC, HJM-561, which selectively degrades the EGFR C797S-containing triple mutants. HJM-561 potently inhibits the proliferation of Del19/T790M/C797S and L858R/T790M/C797S Ba/F3 cells while sparing cells expressing wild type EGFR. Oral administration of HJM-561 shows robust anti-tumor activity in EGFR Del19/T790M/C797S-driven Ba/F3 CDX and PDX models that were resistant to osimertinib treatment. Taken together, our results suggest that HJM-561 is a promising therapeutic option for overcoming EGFR triple mutation-mediated drug resistance in NSCLC.

Conformational Constrained 4-(1-Sulfonyl-3-indol)yl-2-phenylaminopyrimidine Derivatives as New Fourth-Generation Epidermal Growth Factor Receptor Inhibitors Targeting T790M/C797S Mutations

Tertiary C797S mutation of epidermal growth factor receptor (EGFR)-mediated resistance in non-small-cell-lung-cancer (NSCLC) patients is still an unmet clinical need. Several classes of adenosine 5'-triphosphate-competitive or allosteric EGFR^T790M/C797S inhibitors and degraders have been developed, but none of them have received approval from the regulatory agencies. Herein, we report the structure-based design of conformational constrained 4-(1-ethylsufonyl-3-indolyl)-2-phenylaminopyrimidines as new EGFR^T790M/C797S inhibitors by using a macrocyclization strategy. Representative compound 18j potently inhibited EGFR^{19del/T790M/C797S} and EGFR^{L858R/T790M/C797S} mutants with IC₅₀ values of 15.8 and 23.6 nM and suppressed Ba/F3-EGFR^{L858R/T790M/C797S} and Ba/F3-EGFR^{19del/T790M/C797S} cells with IC₅₀ values of 0.036 and 0.052 μM, respectively, which is 10-20-fold more potent than brigatinib. 18j also potently inhibited the EGFR^{19del/T790M/C797S}-mutated PC-9-OR NSCLC cell proliferation with an IC₅₀ value of 0.644 μM but was less potent for parental Ba/F3 and A431 cells. This study provides a new lead compound for drug discovery to combat EGFR^C797S-mediated resistance in NSCLC patients.

Structure-based design of a dual-warhead covalent inhibitor of FGFR4

The fibroblast growth factor 19 (FGF19)/fibroblast growth factor receptor 4 (FGFR4) signaling pathways play critical roles in a variety of cancers, such as hepatocellular carcinoma (HCC). FGFR4 is recognized as a promising target to treat HCC. Currently, all FGFR covalent inhibitors target one of the two cysteines (Cys477 and Cys552). Here, we designed and synthesized a dual-warhead covalent FGFR4 inhibitor, CXF-009, targeting Cys477 and Cys552 of FGFR4. We report the cocrystal structure of FGFR4 with CXF-009, which exhibits a dual-warhead covalent binding mode. CXF-009 exhibited stronger selectivity for FGFR4 than FGFR1-3 and other kinases. CXF-009 can also potently inhibit the single cystine mutants, FGFR4(C477A) and FGFR4(C552A), of FGFR4. In summary, our study provides a dual-warhead covalent FGFR4 inhibitor that can covalently target two cysteines of FGFR4. CXF-009, to our knowledge, is the first reported inhibitor that forms dual-warhead covalent bonds with two cysteine residues in FGFR4. CXF-009 also has the potential to overcome drug induced resistant FGFR4 mutations and might serve as a lead compound for future anticancer drug discovery.

EGFR and COX-2 Dual Inhibitor: The Design, Synthesis, and Biological Evaluation of Novel Chalcones

For most researchers, discovering new anticancer drugs to avoid the adverse effects of current ones, to improve therapeutic benefits and to reduce resistance is essential. Because the COX-2 enzyme plays an important role in various types of cancer leading to malignancy enhancement, inhibition of apoptosis, and tumor-cell metastasis, an indispensable objective is to design new scaffolds or drugs that possess combined action or dual effect, such as kinase and COX-2 inhibition. The start compounds A1 to A6 were prepared through the diazo coupling of 3-aminoacetophenone with a corresponding phenol and then condensed with two new chalcone series, C7–18. The newly synthesized compounds were assessed against both COX-2 and epidermal growth factor receptor (EGFR) for their inhibitory effect. All novel compounds were screened for cytotoxicity against five cancer cell lines. Compounds C9 and G10 exhibited potent EGFR inhibition with IC₅₀ values of 0.8 and 1.1 µM, respectively. Additionally, they also displayed great COX-2 inhibition with IC₅₀ values of 1.27 and 1.88 µM, respectively. Furthermore, the target compounds were assessed for their cytotoxicity against pancreatic ductal cancer (Panc-1), lung cancer (H-460), human colon cancer (HT-29), human malignant melanoma (A375) and pancreatic cancer (PaCa-2) cell lines. Interestingly, compounds C10 and G12 exhibited the strongest cytotoxic effect against PaCa-2 with average IC₅₀ values of 0.9 and 0.8 µM, respectively. To understand the possible binding modes of the compounds under investigation with the receptor cites of EGFR and COX-2, a virtual docking study was conducted.

Design, Synthesis, and Biological Evaluation of Novel EGFR PROTACs Targeting Del19/T790M/C797S Mutation

The tertiary epidermal growth factor receptor (EGFR) C797S mutation predominates in the acquired mutational resistance in cancer patients to third-generation EGFR inhibitors. Small-molecule inhibitors targeting the EGFR C797S mutation have been developed with good efficiency. However, these compounds may still induce new EGFR mutations to evade the inhibition pathway. One EGFR protein degrader based on an allosteric inhibitor has shown some benefits of degrading the EGFR L858R/T790M/C797S triple mutant. However, the degrader of the other important triple EGFR mutation Del19/T790M/C797S has not been reported. Here we present the design and synthesis of a series of EGFR proteolysis-targeting chimeras (PROTACs) that can rapidly and potently induce EGFR degradation in Ba/F3 cells expressing the EGFR^{Del19/T790M/C797S} mutant. One representative compound 6h time- and dose-dependently induced EGFR degradation with a DC₅₀ of 8 nM. It also showed good antiproliferation activity (IC₅₀ = 0.02 μM) against Ba/F3-EGFR^{Del19/T790M/C797S} cells. 6h may serve as a lead compound to develop therapeutic agents for the treatment of resistant non-small cell lung cancer patients with EGFR C797S mutants.

A sulfonyl fluoride derivative inhibits EGFRL858R/T790M/C797S by covalent modification of the catalytic lysine

The emergence of the C797S mutation in EGFR is a frequent mechanism of resistance to osimertinib in the treatment of non-small cell lung cancer (NSCLC). In the present work, we report the design, synthesis and biochemical characterization of UPR1444 (compound 11), a new sulfonyl fluoride derivative which potently and irreversibly inhibits EGFR^{L858R/T790M/C797S} through the formation of a sulfonamide bond with the catalytic residue Lys745. Enzymatic assays show that compound 11 displayed an inhibitory activity on EGFR^WT comparable to that of osimertinib, and it resulted more selective than the sulfonyl fluoride probe XO44, recently reported to inhibit a significant part of the kinome. Neither compound 11 nor XO44 inhibited EGFR^{del19/T790M/C797S} triple mutant. When tested in Ba/F3 cells expressing EGFR^{L858R/T790M/C797S}, compound 11 resulted significantly more potent than osimertinib at inhibiting both EGFR autophosphorylation and proliferation, even if the inhibition of EGFR autophosphorylation by compound 11 in Ba/F3 cells was not long lasting.

Design, synthesis and biological evaluation of novel N-(3-amino-4-methoxyphenyl)acrylamide derivatives as selective EGFRL858R/T790M kinase inhibitors

On the basis of N-(3-amino-4-methoxyphenyl)acrylamide scaffold, a series of novel compounds containing 3-substitutional-1-methyl-1H-indole, 2-substitutional pyrrole or thiophene moieties were synthesized and their in vitro antiproliferation activities against A549 and H1975 cell lines were evaluated. The results indicated that most of the compounds showed moderate to excellent antitumor activities. Especially, compounds 9a (A549 IC₅₀ = 1.96 μM, H1975 IC₅₀ = 0.095 μM), 17i (A549 IC₅₀ = 4.17 μM, H1975 IC₅₀ = 0.052 μM), 17j (A549 IC₅₀ = 1.67 μM, H1975 IC₅₀ = 0.061 μM) exhibited comparable antitumor activities and selectivity ratios compared to the positive control osimertinib (A549 IC₅₀ = 2.91 μM, H1975 IC₅₀ = 0.064 μM). In vitro inhibitory activities against EGFR kinases containing different mutations were also tested. Compound 17i showed remarkable inhibitory activity (with IC₅₀ value of 1.7 nM) to EGFR^L858R/T790M kinase and selectivity (22-folds compared to EGFR^WT kinase). Furthermore, acridine orange/ethidium bromide (AO/EB) staining assay, cell apoptosis assay, cell cycle distribution assay and wound-healing assay of the compounds 9a and 17i were performed on H1975 cell line. The results showed dose-dependent activities of the induction of apoptosis, G0/G1-phase arrestation and inhibition of migration, which were similar to the positive control osimertinib. Additionally, molecular docking analysis was performed to seek the possible binding mode between the selected compounds (9a, 17i-17j) and EGFR^L858R/T790M kinase. The results demonstrated that compound 17i is a promising candidate and worth further study.

Circulating Tumour Cells (CTCs) in NSCLC: From Prognosis to Therapy Design

Designing optimal (neo)adjuvant therapy is a crucial aspect of the treatment of non-small-cell lung carcinoma (NSCLC). Standard methods of chemotherapy, radiotherapy, and immunotherapy represent effective strategies for treatment. However, in some cases with high metastatic activity and high levels of circulating tumour cells (CTCs), the efficacy of standard treatment methods is insufficient and results in treatment failure and reduced patient survival. CTCs are seen not only as an isolated phenomenon but also a key inherent part of the formation of metastasis and a key factor in cancer death. This review discusses the impact of NSCLC therapy strategies based on a meta-analysis of clinical studies. In addition, possible therapeutic strategies for repression when standard methods fail, such as the administration of low-toxicity natural anticancer agents targeting these phenomena (curcumin and flavonoids), are also discussed. These strategies are presented in the context of key mechanisms of tumour biology with a strong influence on CTC spread and metastasis (mechanisms related to tumour-associated and -infiltrating cells, epithelial–mesenchymal transition, and migration of cancer cells).

A Review: Discovering 1,3,4-oxadiazole and chalcone nucleus for cytotoxicity/EGFR inhibitory anticancer activity

INTRODUCTION

Cancer is reported to be one of the most life-threatening diseases. Major limitations of currently used anticancer agents are drug resistance, very small therapeutic index, and severe, multiple side effects.

OBJECTIVE

The current scenario necessitates developing new anticancer agents, acting on novel targets for effectively controlling cancer. The epidermal growth factor receptor is one such target, which is being explored for 1,3,4-oxadiazole and chalcone nuclei.

METHOD

Findings of different researchers working on these scaffolds have been reviewed and analyzed, and the outcomes were summarized. This review focuses on Structure-Activity Relationship studies (SARs) and computational studies of various 1,3,4-oxadiazole and chalcone hybrids/derivatives reported as cytotoxic/EGFR-TK inhibitory anticancer activity.

RESULT AND CONCLUSION

1,3,4-oxadiazole and chalcone hybrids/derivatives with varied substitutions are found to be effective pharmacophores in obtaining potent anticancer activity. Having done a thorough literature survey, we conclude that this review will surely provide firm and better insights to the researchers to design and develop potent hybrids/derivatives that inhibit EGFR.

Hype or hope - Can combination therapies with third-generation EGFR-TKIs help overcome acquired resistance and improve outcomes in EGFR-mutant advanced/metastatic NSCLC?

Three generations of epidermal growth factor receptor - tyrosine kinase inhibitors (EGFR-TKIs) have been developed for treating advanced/metastatic non-small cell lung cancer (NSCLC) patients harboring EGFR-activating mutations, while a fourth generation is undergoing preclinical assessment. Although initially effective, acquired resistance to EGFR-TKIs usually arises within a year due to the emergence of clones harboring multiple resistance mechanisms. Therefore, the combination of EGFR-TKIs with other therapeutic agents has emerged as a potential strategy to overcome resistance and improve clinical outcomes. However, results obtained so far are ambiguous and ideal therapies for patients who experience disease progression during treatment with EGFR-TKIs remain elusive. This review provides an updated landscape of EGFR-TKIs, along with a description of the mechanisms causing resistance to these drugs. Moreover, it discusses the current knowledge, limitations, and future perspective regarding the use of EGFR-TKIs in combination with other anticancer agents, supporting the need for bench-to-bedside approaches in selected populations.

The synthesis and bioactivity of pyrrolo[2,3-d]pyrimidine derivatives as tyrosine kinase inhibitors for NSCLC cells with EGFR mutations

EGFR mutations are an ongoing challenge in the treatment of NSCLC, and demand continuous updating of EGFR TKI drug candidates. Pyrrolopyrimidines are one group of versatile scaffolds suitable for tailored drug development. However not many precedents of this type of pharmacophore have been investigated in the realm of third generation of covalent EGFR-TKIs. Herein, a series of pyrrolo[2,3-d]pyrimidine derivatives able to block mutant EGFR activity in a covalent manner were synthesized, through optimized Buchwald-Hartwig C-N cross coupling reactions. Their preliminary bioactivity and corresponding inhibitory mechanistic pathways were investigated at molecular and cellular levels. Several compounds exhibited increased biological activity and enhanced selectivity compared to the control compound. Notably, compound 12i selectively inhibits HCC827 cells harboring the EGFR activating mutation with up to 493-fold increased efficacy compared to in normal HBE cells. Augmented selectivity was also confirmed by kinase enzymatic assay, with the test compound selectively inhibiting the T790 M activating mutant EGFRs (IC₅₀ values of 0.21 nM) with up to 104-fold potency compared to the wild-type EGFR (IC₅₀ values of 22 nM). Theoretical simulations provide structural evidence of selective kinase inhibitory activity. Thus, this series of pyrrolo[2,3-d]pyrimidine derivatives could serve as a starting point for the development of new EGFR-TKIs.

Acquired resistance to third-generation EGFR-TKIs and emerging next-generation EGFR inhibitors

The discovery that mutations in the EGFR gene are detected in up to 50% of lung adenocarcinoma patients, along with the development of highly efficacious epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs), has revolutionized the treatment of this frequently occurring lung malignancy. Indeed, the clinical success of these TKIs constitutes a critical milestone in targeted cancer therapy. Three generations of EGFR-TKIs are currently approved for the treatment of EGFR mutation-positive non-small cell lung cancer (NSCLC). The first-generation TKIs include erlotinib, gefitinib, lapatinib, and icotinib; the second-generation ErbB family blockers include afatinib, neratinib, and dacomitinib; whereas osimertinib, approved by the FDA on 2015, is a third-generation TKI targeting EGFR harboring specific mutations. Compared with the first- and second-generation TKIs, third-generation EGFR inhibitors display a significant advantage in terms of patient survival. For example, the median overall survival in NSCLC patients receiving osimertinib reached 38.6 months. Unfortunately, however, like other targeted therapies, new EGFR mutations, as well as additional drug-resistance mechanisms emerge rapidly after treatment, posing formidable obstacles to cancer therapeutics aimed at surmounting this chemoresistance. In this review, we summarize the molecular mechanisms underlying resistance to third-generation EGFR inhibitors and the ongoing efforts to address and overcome this chemoresistance. We also discuss the current status of fourth-generation EGFR inhibitors, which are of great value in overcoming resistance to EGFR inhibitors that appear to have greater therapeutic benefits in the clinic.

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EGFR gene mutations are detected in about 50% of non-small cell lung cancer (NSCLC) patients worldwide

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The three generations of EGFR tyrosine kinase inhibitors (TKIs) are critical milestones for NSCLC patients

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Like other targeted therapies, new EGFR mutations and coupled drug resistances emerge rapidly after TKI treatment, posing formidable obstacles to cancer management

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The investigational fourth-generation EGFR inhibitors are of great promise, through a number of novel mechanisms, in overcoming these resistances after third-generation TKI treatment, and will bring more benefits to NSCLC patients

Evaluation of Benzamide-chalcone Derivatives as EGFR/CDK2 inhibitor: Synthesis, in-vitro Inhibition, and Molecular Modeling Studies

BACKGROUND

EGFR (Epidermal Growth Factor Receptor) and CDK2 (Cyclin Dependent Kinase 2) are important targets in the treatment of many solid tumors and different ligands of these receptors share many common structural features.

OBJECTIVE

The study involved synthesis of benzamide-substituted chalcones and determination of their antiproliferative activity as well as preliminary evaluation of EGFR and CDK2 inhibitory potential using both receptor binding and computational methods.

METHODS

We synthesized 13 benzamide-substituted chalcone derivatives and tested their antiproliferative activity against MCF-7, HT-29 and U373MG cell-lines using Sulforhodamine B Assay. Four compounds were examined for activity against EGFR and CDK2 kinase. The compounds were docked into both EGFR and CDK2 using Glide software. The stability of the interactions for most active compound was evaluated by Molecular Dynamics Simulation using Desmond software. Molecular Docking studies on mutant EGFR (T790M, T790M/L858R, and T790M/C797S) were also carried out.

RESULTS

From the SRB assay, we concluded that compounds 1g, and 1k were effective in inhibiting the growth of MCF-7 cell line whereas the other compounds were moderately active. Most compounds were either moderately active or inactive on U373 MG and HT-29 cell line. Compounds 1g and 1k showed good inhibitory activity against CDK2 kinase while 1d and 1f were moderately active. Compounds 1d, 1f, 1g, and 1k were moderately active against EGFR kinase. Molecular docking reveals involvement of one hydrogen bond with Met793 in binding with EGFR however; it was not stable during simulation and these compounds bind to the receptor mainly via hydrophobic contacts. This fact also points towards a different orientation of the inhibitor within the active site of EGFR kinase. Binding mode analysis for CDK2 inhibition studies indicate that hydrogen bonding interaction with Lys 33 and Leu83 are important for the activity. These interactions were found to be stable throughout the simulation. Considering the results for wild-type EGFR inhibition, the docking studies on mutants were performed and which indicate that the compounds bind to the mutant EGFR but the amino acid residues involved are similar to the wild-type EGFR and therefore, the selectivity seems to be limited.

CONCLUSION

These benzamide-substituted chalcone derivatives will be useful as lead molecules for the further development of newer inhibitors of EGFR and/or CDK2 kinases.