Targeting kinases with anilinopyrimidines: discovery of N-phenyl-N'-[4-(pyrimidin-4-ylamino)phenyl]urea derivatives as selective inhibitors of class III receptor tyrosine kinase subfamily

Development of new anticancer thiadiazole-sulfonamides as dual EGFR/carbonic anhydrase inhibitors

BACKGROUND

Thiadiazole-sulfonamide derivatives were synthesized as dual inhibitors of epidermal growth factor receptor (EGFR) and carbonic anhydrase IX (CA-IX) to develop selective anticancer agents.

METHODS

Cytotoxicity was evaluated against MDA-MB-231 and MCF-7 breast cancer cells, with selectivity tested on Vero cells. Enzymatic inhibition studies were conducted against EGFR and CA-IX, using erlotinib and acetazolamide as reference drugs. Apoptosis was assessed through gene expression analysis of BAX/Bcl-2, caspase-8, and caspase-9, alongside flow cytometry for apoptosis and cell cycle analysis. Molecular docking and 200 ns molecular dynamics (MD) simulations evaluated binding interactions. Density Functional Theory (DFT) calculations and in silico ADMET predictions assessed stability, electronic properties, and safety.

RESULTS

Compound 14 exhibited potent cytotoxicity (IC₅₀ = 5.78 μM, MDA-MB-231; 8.05 μM, MCF-7) and high selectivity (IC₅₀ = 313.08 μM, Vero). It inhibited EGFR (IC₅₀ = 5.92 nM) and CA-IX (IC₅₀ = 63 nM), surpassing reference drugs. Apoptosis induction was confirmed by a 13.97-fold increase in BAX/Bcl-2, caspase upregulation, and G1-phase arrest. Computational analyses confirmed stable binding and favorable safety.

CONCLUSIONS

Compound 14 represents a promising dual EGFR/CA-IX inhibitor with selective anticancer activity. Further in vivo studies are warranted.

Radiation-induced nanogel engineering based on pectin for pH-responsive rutin delivery for cancer treatment

This research investigates the formulation of a nanogel complex using pectin and poly(acrylic acid) (PAAc) to encapsulate rutin. The nanogel's pH-responsive behavior and its potential as a targeted drug delivery platform are investigated. The gamma irradiation-induced crosslinking mechanism is elucidated, highlighting its role in creating a stable three-dimensional network structure within the polymer matrix. Fourier transform infrared spectroscopy analysis sheds light on the molecular interactions within rutin and the nanogel-rutin complex. The pH-responsive behavior of the nanogel is explored, showcasing its ability to release rutin selectively in response to pH variations and displaying high physical and chemical stability. Transmission electron microscopy imaging provides visual insights into nanogel morphology and interactions. The cumulative drug content from the nanogel was 86.14 ± 2.61%. The pH-dependent release profile of the nanogel was examined, demonstrating selective rutin release in response to varying pH levels. Cytotoxicity studies were conducted against four human cancer cell lines-HepG2, A549, MCF-7, and HCT-116 showing significant reductions in IC50 values, indicating enhanced therapeutic efficacy. Additionally, molecular docking studies revealed strong binding interactions of rutin with VEGFR-2 and EGFRT790M. Our nanogel compound 5 significantly reduced the IC50 values for HepG2, A549, MCF-7, and HCT-116 cells by 58.19%, 81.29%, 71.81%, and 67.16%, respectively. Furthermore, it lowered the IC50 values for VEGFR-2 and EGFRT790M by 29.66% and 68.18%, respectively.

New apoptotic anti-triple-negative breast cancer theobromine derivative inhibiting EGFRWT and EGFRT790M: in silico and in vitro evaluation

A new theobromine-derived EGFR inhibitor (2-(3,7-Dimethyl-2,6-dioxo-2,3,6,7-tetrahydro-1H-purin-1-yl)-N-(2,6-dimethylphenyl)acetamide) has been developed that has the essential structural characteristics to interact with EGFR's pocket. The designed compound is 2,6-di ortho methylphenyl)acetamide derivative of the well-known alkaloid, theobromine, (T-1-DOMPA). Firstly, deep DFT studies have been conducted to study the optimized chemical structure, molecular orbital and chemical reactivity analysis of T-1-DOMPA. Then, T-1-DOMPA's anticancer potentialities were estimated first through a structure-based computational approach. Utilizing molecular docking, molecular dynamics, MD, simulations over 100 ns, MM-PBSA and PLIP studies, T-1-DOMPA bonded to and inhibited the EGFR protein effectively. Subsequently, the ADMET profiles of T-1-DOMPA were computed before preparation, and its drug-likeness was anticipated. Therefore, T-1-DOMPA was prepared for the purposes of scrutinizing both the design and the results obtained in silico. The in vitro potential of T-1-DOMPA against triple-negative breast cancer cell lines, MDA- MB-231, was very promising with an IC50 value of1.8 µM, comparable to the reference drug (0.9 µM), and a much higher selectivity index of 2.6. Interestingly, T-1-DOMPA inhibited three other cancer cell lines (CaCO-2, HepG-2, and A549) with IC50 values of 1.98, 2.53, and 2.39 µM exhibiting selectivity index values of 2,4, 1.9, and 2, respectively. Additionally, T-1-DOMPA prevented effectively the MDA-MB-231cell line's healing and migration abilities. Also, T-1-DOMPA's abilities to induce apoptosis were confirmed by acridine orange/ethidium bromide (AO/EB) staining assay. Finally, T-1-DOMPA caused an up-regulation of the gene expression of the apoptotic gene, Caspase-3, in the treated MDA-MB-231cell.

New Theobromine Apoptotic Analogue with Anticancer Potential Targeting the EGFR Protein: Computational and In Vitro Studies

AIM

The aim of this study was to design and examine a novel epidermal growth factor receptor (EGFR) inhibitor with apoptotic properties by utilizing the essential structural characteristics of existing EGFR inhibitors as a foundation.

METHOD

The study began with the natural alkaloid theobromine and developed a new semisynthetic derivative (T-1-PMPA). Computational ADMET assessments were conducted first to evaluate its anticipated safety and general drug-likeness. Deep density functional theory (DFT) computations were initially performed to validate the three-dimensional (3D) structure and reactivity of T-1-PMPA. Molecular docking against the EGFR proteins was conducted to investigate T-1-PMPA's binding affinity and inhibitory potential. Additional molecular dynamics (MD) simulations over 200 ns along with MM-GPSA, PLIP, and principal component analysis of trajectories (PCAT) experiments were employed to verify the binding and inhibitory properties of T-1-PMPA. Afterward, T-1-PMPA was semisynthesized to validate the proposed design and in silico findings through several in vitro examinations.

RESULTS

DFT studies indicated T-1-PMPA's reactivity using electrostatic potential, global reactive indices, and total density of states. Molecular docking, MD simulations, MM-GPSA, PLIP, and ED suggested the binding and inhibitory properties of T-1-PMPA against the EGFR protein. The in silico ADMET predicted T-1-PMPA's safety and general drug-likeness. In vitro experiments demonstrated that T-1-PMPA effectively inhibited EGFRWT and EGFR790m, with IC50 values of 86 and 561 nM, respectively, compared to Erlotinib (31 and 456 nM). T-1-PMPA also showed significant suppression of the proliferation of HepG2 and MCF7 malignant cell lines, with IC50 values of 3.51 and 4.13 μM, respectively. The selectivity indices against the two cancer cell lines indicated the overall safety of T-1-PMPA. Flow cytometry confirmed the apoptotic effects of T-1-PMPA by increasing the total percentage of apoptosis to 42% compared to 31, and 3% in Erlotinib-treated and control cells, respectively. The qRT-PCR analysis further supported the apoptotic effects by revealing significant increases in the levels of Casp3 and Casp9. Additionally, T-1-PMPA controlled the levels of TNFα and IL2 by 74 and 50%, comparing Erlotinib's values (84 and 74%), respectively.

CONCLUSION

In conclusion, our study's findings suggest the potential of T-1-PMPA as a promising apoptotic anticancer lead compound targeting the EGFR.

Novel Pyrimidine-5-Carbonitriles as potential apoptotic and antiproliferative agents by dual inhibition of EGFRWT/T790M and PI3k enzymes; Design, Synthesis, biological Evaluation, and docking studies

A new series of 6-(4-fluorophenyl)-2-(methylthio) pyrimidine-5-carbonitrile derivatives were designed and synthesized as EGFR/PI3K dual inhibitors, and potential antiproliferative agents. The new 22 compounds were screened by DTP-NCI against all NCI60 cell lines. Almost all compounds showed cytotoxic activity. Compound 7c showed a promising antitumour activity on CNS cancer (SNB-75), and ovarian cancer (OVAR-4) with IC50 < 0.01, and 0.64 µM, respectively. Fortunately, 7c exhibited a better safety profile on normal cells (WI-38) than doxorubicin by 2.2-fold. Compound 7c displayed selective inhibitory activity on EGFRt790m over EGFRWT with IC50 = 0.08, and 0.13 µM, respectively, wherefore it might overcome EGFR-TKIs resistance. In addition to its remarkable inhibitory activity on all PI3K isoforms, specifically PI3K-δ with IC50 = 0.64 µM Compared with LY294002 IC50 = 7.6 µM. Compound 7c arrested the cell cycle of SNB-75 & OVAR-4 at the G0-G1 phase coupled with apoptosis induction. The western blotting analysis approved decreasing the expression level of p-AKT coupled with an increase in Casp3, Casp9, and BAX proteins in the SNB-75 & OVAR-4 after being treated with 7c which may support the suggested mechanism of action of 7c as EGFR/PI3K dual inhibitor. Physicochemical parameters were forecasted using SwissADME online tool. MD showed the interaction of 7c with the crucial amino acids of the active domain of both EGFR/PI3K which may explain its potent inhibitory activities. In vivo study disclosed a significant decrease in tumor weight and the number of nodules in the group of mice treated with 7c compared with the control group.

Visible-light promoted catalyst-free (VLCF) multi-component synthesis of spiro indolo-quinazolinone-pyrrolo[3,4-a]pyrrolizine hybrids: evaluation of in vitro anticancer activity, molecular docking, MD simulation and DFT studies

A new and highly efficient visible-light-promoted catalyst free (VLCF) strategy for neat and clean synthesis of spiro indolo-quinazolinone-pyrrolo[3,4-a]pyrrolizine hybrids (6a-d) has been introduced. We have performed visible-light triggered 1,3-Dipolar cycloaddition reaction of maleimide (5a-d) with azomethine ylide generated in situ derived from tryptanthrin (3) and L-proline (4) to obtain desired products (6a-d) in good to excellent yield. Authentication and characterization of product was done using various spectroscopic techniques such as IR, 1H NMR, 13C NMR, Mass spectrometry and single crystal XRD analysis. To explain the reaction spontaneity, product stability, reactivity as well as possible mode of the interaction a quantum chemical investigation was performed and depicted through DFT studies. The synthesized compound 6a was also evaluated for anti-proliferative activity against a panel of five cancer cell lines (MCF-7, MDA-MB-231, HeLa, PC-3 and Ishikawa) and normal human embryonic kidney (HEK-293) cell line by using MTT assay. Compound 6a showed very good in vitro anti-proliferative activity (IC50  = 6.58-17.98 μM) against four cancer cell lines and no cytotoxicity against normal HEK-293. In order to evaluate the anticancer potential of compounds 6a-d, molecular docking was performed against wild type and mutant EGFR. The results suggest that all the compounds occupied the active site of both enzymes, with a strong binding energy (-10.2 to -11.5 kcal/mol). These results have been confirmed by molecular dynamics simulation by evaluating root mean square deviation (RMSD) and root mean square fluctuation (RMSF), along with principal component analysis (PCA).Communicated by Ramaswamy H. Sarma.

Computer aided drug discovery (CADD) of a thieno[2,3-d]pyrimidine derivative as a new EGFR inhibitor targeting the ribose pocket

Depending on the pharmacophoric characteristics of EGFR inhibitors, a new thieno[2,3-d]pyrimidine derivative has been developed. Firstly, the potential inhibitory effect of the designed compound against EGFR has been proven by docking experiments that showed correct binding modes and excellent binding energies of -98.44 and -88.00 kcal/mol, against EGFR wild-type and mutant type, respectively. Furthermore, MD simulations studies confirmed the precise energetic, conformational, and dynamic alterations that occurred after binding to EGFR. The correct binding was also confirmed by essential dynamics studies. To further investigate the general drug-like properties of the developed candidate, in silico ADME and toxicity studies have also been carried out. The thieno[2,3-d]pyrimidine derivative was synthesized following the earlier promising findings. Fascinatingly, the synthesized compound (4) showed promising inhibitory effects against EGFRWT and EGFRT790M with IC50 values of 25.8 and 182.3 nM, respectively. Also, it exhibited anticancer potentialities against A549 and MCF-7cell lines with IC50 values of 13.06 and 20.13 µM, respectively. Interestingly, these strong activities were combined with selectivity indices of 2.8 and 1.8 against the two cancer cell lines, respectively. Further investigations indicated the ability of compound 4 to arrest the cancer cells' growth at the G2/M phase and to increase early and late apoptosis percentages from 2.52% and 2.80 to 17.99% and 16.72%, respectively. Additionally, it was observed that compound 4 markedly increased the levels of caspase-3 and caspase-9 by 4 and 3-fold compared to the control cells. Moreover, it up-regulated the level of BAX by 3-fold and down-regulated the level of Bcl-2 by 3-fold affording a BAX/Bcl-2 ratio of 9.Communicated by Ramaswamy H. Sarma.

Computer-Assisted Drug Discovery of a Novel Theobromine Derivative as an EGFR Protein-Targeted Apoptosis Inducer

The overexpression of the Epidermal Growth Factor Receptor (EGFR) marks it as a pivotal target in cancer treatment, with the aim of reducing its proliferation and inducing apoptosis. This study aimed at the CADD of a new apoptotic EGFR inhibitor. The natural alkaloid, theobromine, was used as a starting point to obtain a new semisynthetic (di-ortho-chloro acetamide) derivative (T-1-DOCA). Firstly, T-1-DOCA's total electron density, energy gap, reactivity indices, and electrostatic surface potential were determined by DFT calculations, Then, molecular docking studies were carried out to predict the potential of T-1-DOCA against wild and mutant EGFR proteins. T-1-DOCA's correct binding was further confirmed by molecular dynamics (MD) over 100 ns, MM-GPSA, and PLIP experiments. In vitro, T-1-DOCA showed noticeable efficacy compared to erlotinib by suppressing EGFRWT and EGFRT790M with IC50 values of 56.94 and 269.01 nM, respectively. T-1-DOCA inhibited also the proliferation of H1975 and HCT-116 malignant cell lines, exhibiting IC50 values of 14.12 and 23.39 µM, with selectivity indices of 6.8 and 4.1, respectively, indicating its anticancer potential and general safety. The apoptotic effects of T-1-DOCA were indicated by flow cytometric analysis and were further confirmed through its potential to increase the levels of BAX, Casp3, and Casp9, and decrease Bcl-2 levels. In conclusion, T-1-DOCA, a new apoptotic EGFR inhibitor, was designed and evaluated both computationally and experimentally. The results suggest that T-1-DOCA is a promising candidate for further development as an anti-cancer drug.

Towards targeting EGFR and COX-2 inhibitors: comprehensive computational studies on the role of chlorine group in novel thienyl-pyrazoline derivative

To enhance the effectiveness of chemotherapy and overcome resistance, scientists must develop novel drugs or scaffolds that have a combined effect, such as the inhibition of EGFR and COX-2. This research employed virtual screening techniques, such as docking, and dynamics simulation, to predict chlorinated thienyl-pyrazoline derivatives that inhibit these proteins. The study proposed eleven (11) ligands with binding energies ranging from -7.8 kcal/mol to -8.7 kcal/mol for EGFR and -6.4 kcal/mol to -8.4 kcal/mol for COX-2. Ligands P1 and P11 exhibited the highest binding affinity for both proteins. The results of RMSD, RMSF, RoG, SASA the number of hydrogen bonds, and BAR free binding energy demonstrated the good stability of ligands P1 and P11 when binding to both proteins over 180 ns simulations. In addition, the absorption, distribution, metabolism, excretion, and toxicity properties of the selected ligands were assessed to predict their toxicity and drug likeliness. Based on the results, these compounds can be proposed for further synthesis and in vitro studies.Communicated by Ramaswamy H. Sarma.

Discovery of new thieno[2,3-d]pyrimidines as EGFR tyrosine kinase inhibitors for cancer treatment

Background: EGFR has been considered a vital molecular target in cancer management. Aim: The discovery of new thieno[2,3-d]pyrimidine derivatives as EGFR tyrosine kinase inhibitors. Methods: Nine derivatives were designed, synthesized and subjected to in vitro and in silico studies. Results: Compound 7a significantly inhibited the growth of HepG2 and PC3 cells for both EGFR wild-type and EGFRT790M. Compound 7a caused a significant apoptotic effect, arresting HepG2 cells' growth in the S and G2/M phases. Docking and molecular dynamics simulation studies confirmed the correct and stable binding modes of the synthesized compounds against the active sites. Conclusion: Compound 7a is a promising dual EGFR inhibitor for cancer treatment.

Design, synthesis, and docking of novel thiazolidine-2,4-dione multitarget scaffold as new approach for cancer treatment

Novel thiazolidine-2,4-diones have been developed and estimated as conjoint inhibitors of EGFR^T790M and VEGFR-2 against HCT-116, MCF-7, A549, and HepG2 cells. Compounds 6a, 6b, and 6c were known to be the dominant advantageous congeners against HCT116 (IC₅₀  = 15.22, 8.65, and 8.80 µM), A549 (IC₅₀  = 7.10, 6.55, and 8.11 µM), MCF-7 (IC₅₀  = 14.56, 6.65, and 7.09 µM) and HepG2 (IC₅₀  = 11.90, 5.35, and 5.60 µM) mass cell lines, correspondingly. Although compounds 6a, 6b, and 6c disclosed poorer effects than sorafenib (IC₅₀  = 4.00, 4.04, 5.58, and 5.05 µM) against the tested cell sets, congeners 6b and 6c demonstrated higher actions than erlotinib (IC₅₀  = 7.73, 5.49, 8.20, and 13.91 µM) against HCT116, MCF-7 and HepG2 cells, yet lesser performance on A549 cells. The hugely effective derivatives 4e-i and 6a-c were inspected versus VERO normal cell strains. Compounds 6b, 6c, 6a, and 4i were found to be the most effective derivatives, which suppressed VEGFR-2 by IC₅₀  = 0.85, 0.90, 1.50, and 1.80 µM, respectively. Moreover, compounds 6b, 6a, 6c, and 6i could interfere with the EGFR^T790M performing strongest effects with IC₅₀  = 0.30, 0.35, 0.50, and 1.00 µM, respectively. What is more, 6a, 6b, and 6c represented satisfactory in silico computed ADMET profile.

Design, synthesis, and anticancer evaluation of N6 -hydrazone purine derivatives with potential antiplatelet aggregation activity

In our research on novel anticancer agents, a series of N⁶ -hydrazone purine derivatives were designed and synthesized by analysis of a pharmacophore model for ATP-competitive inhibitors. The activities screening results showed that N⁶ -hydrazone purine derivatives 21 and 26 not only showed potential antiproliferative activity against the A549 and MCF-7 cell lines comparable to Vandetanib as a positive control but also had moderate antiplatelet aggregation activity. In order to investigate the possible targets, a molecular docking study was carried out on the fourteen kinases associated with anticancer and antiplatelet aggregation activities. The results indicated that compounds 21 and 26 had the potential activity to target VEGFR-2, PI3Kα, EGFR, and HER2 kinases. The inhibition of the kinases assay showed that compound 26 could target VEGFR-2, PI3Kα, and EGFR (IC₅₀  = 0.822, 3.040 and 6.625 μM). All results indicated that compound 26 will be an encouraging framework as potential new multi-target anticancer agent with potential antiplatelet aggregation activity.

Exploration of thiazolidine-2,4-diones as tyrosine kinase inhibitors: Design, synthesis, ADMET, docking, and antiproliferative evaluations

As dual EGFR and VEGFR-2 inhibitors, 22 innovative thiazolidine-2,4-diones were modeled, constructed, and measured for their anticancer performance versus four human neoplasms HCT-116, MCF-7, A549, and HepG2. Molecular docking and MD simulation were performed to inspect the binding technique of the proffered congeners with the EGFR and VEGFR-2 receptors. Evidence realized thanks to the docking inquests was vastly consistent together with that detected through the biological screening. Structures 14a and 14g emerged as the most active compounds toward HCT116 (IC₅₀  = 6.01 and 7.44 µM), MCF-7 (IC₅₀  = 5.77 and 7.23 µM), A549 (IC₅₀  = 5.35 and 5.47 µM) and HepG2 (IC₅₀  = 3.55 and 3.85 µM) tumefaction cells. Compounds 14a and 14g exhibited higher events than sorafenib (IC₅₀  = 5.05, 5.58, 4.04, and 4.00 µM) against HepG2 instead subordinate incidents concerning A549, MCF-7, and HCT116, parallelly. Nevertheless, these compounds signified weightier performance than erlotinib (IC₅₀  = 13.91, 8.20, 5.49, 7.73, and µM), with respect to the four cell lines. Compounds having the best activity against the four cell lines, 12a-f, 13a-d, and 14a-g were chosen to appraise their in vitro VEGFR-2 and EGFR^T790M inhibiting activities. The best results were for compounds 14a and 14g compared to sorafenib and erlotinib, respectively, with IC₅₀ values of 0.74 and 0.78 µM and 0.12 and 0.14 µM, respectively. Moreover, 13d, 14a, and 14g showed an adequate in silico calculated ADMET profile. The current investigation presents novel candidates for future optimization to construct mightier and eclectic binary VEGFR-2/EGFR^T790M restrainers with higher antitumor effects.

A New Anticancer Semisynthetic Theobromine Derivative Targeting EGFR Protein: CADDD Study

A new lead compound has been designed as an antiangiogenic EGFR inhibitor that has the pharmacophoric characteristics to bind with the catalytic pocket of EGFR protein. The designed lead compound is a (para-chloro)acetamide derivative of the alkaloid, theobromine, (T-1-PCPA). At first, we started with deep density functional theory (DFT) calculations for T-1-PCPA to confirm and optimize its 3D structure. Additionally, the DFT studies identified the electrostatic potential, global reactive indices and total density of states expecting a high level of reactivity for T-1-PCPA. Secondly, the affinity of T-1-PCPA to bind and inhibit the EGFR protein was studied and confirmed through detailed structure-based computational studies including the molecular docking against EGFR^WT and EGFR^T790M, Molecular dynamics (MD) over 100 ns, MM-GPSA and PLIP experiments. Before the preparation, the computational ADME and toxicity profiles of T-1-PCPA have been investigated and its safety and the general drug-likeness predicted. Accordingly, T-1-PCPA was semi-synthesized to scrutinize the proposed design and the obtained in silico results. Interestingly, T-1-PCPA inhibited in vitro EGFR^WT with an IC₅₀ value of 25.35 nM, comparing that of erlotinib (5.90 nM). Additionally, T-1-PCPA inhibited the growth of A549 and HCT-116 malignant cell lines with IC₅₀ values of 31.74 and 20.40 µM, respectively, comparing erlotinib that expressed IC₅₀ values of 6.73 and 16.35 µM, respectively.

Anticancer derivative of the natural alkaloid, theobromine, inhibiting EGFR protein: Computer-aided drug discovery approach

A new semisynthetic derivative of the natural alkaloid, theobromine, has been designed as a lead antiangiogenic compound targeting the EGFR protein. The designed compound is an (m-tolyl)acetamide theobromine derivative, (T-1-MTA). Molecular Docking studies have shown a great potential for T-1-MTA to bind to EGFR. MD studies (100 ns) verified the proposed binding. By MM-GBSA analysis, the exact binding with optimal energy of T-1-MTA was also identified. Then, DFT calculations were performed to identify the stability, reactivity, electrostatic potential, and total electron density of T-1-MTA. Furthermore, ADMET analysis indicated the T-1-MTA's general likeness and safety. Accordingly, T-1-MTA has been synthesized to be examined in vitro. Intriguingly, T-1-MTA inhibited the EGFR protein with an IC50 value of 22.89 nM and demonstrated cytotoxic activities against the two cancer cell lines, A549, and HCT-116, with IC50 values of 22.49, and 24.97 μM, respectively. Interestingly, T-1-MTA's IC50 against the normal cell lines, WI-38, was very high (55.14 μM) indicating high selectivity degrees of 2.4 and 2.2, respectively. Furthermore, the flow cytometry analysis of A549 treated with T-1-MTA showed significantly increased ratios of early apoptosis (from 0.07% to 21.24%) as well as late apoptosis (from 0.73% to 37.97%).

Tyrosine Kinase Inhibitors for Glioblastoma Multiforme: Challenges and Opportunities for Drug Delivery

Glioblastoma multiforme (GBM) is an aggressive brain tumor with high mortality rates. Due to its invasiveness, heterogeneity, and incomplete resection, the treatment is very challenging. Targeted therapies such as tyrosine kinase inhibitors (TKIs) have great potential for GBM treatment, however, their efficacy is primarily limited by poor brain distribution due to the presence of the blood-brain barrier (BBB). This review focuses on the potential of TKIs in GBM therapy and provides an insight into the reasons behind unsuccessful clinical trials of TKIs in GBM despite the success in treating other cancer types. The main section is dedicated to the use of promising drug delivery strategies for targeted delivery to brain tumors. Use of brain targeted delivery strategies can help enhance the efficacy of TKIs in GBM. Among various drug delivery approaches used to bypass or cross BBB, utilizing nanocarriers is a promising strategy to augment the pharmacokinetic properties of TKIs and overcome their limitations. This is because of their advantages such as the ability to cross BBB, chemical stabilization of drug in circulation, passive or active targeting of tumor, modulation of drug release from the carrier, and the possibility to be delivered via non-invasive intranasal route.

Design, synthesis, and anti-cancer evaluation of new pyrido[2,3-d]pyrimidin-4(3H)-one derivatives as potential EGFRWT and EGFRT790M inhibitors and apoptosis inducers

A new series of pyrido[2,3-d]pyrimidin-4(3H)-one derivatives having the essential pharmacophoric features of EGFR inhibitors has been designed and synthesised. Cell viability screening was performed for these compounds against A-549, PC-3, HCT-116, and MCF-7 cell lines at a dose of 100 μM. The highest active derivatives (8a, 8 b, 8d, 9a, and 12b) were selected for IC₅₀ screening. Compounds 8a, 8 b, and 9a showed the highest cytotoxic activities and were further investigated for wild EGFR^WT and mutant EGFR^T790M inhibitory activities. Compound 8a showed the highest inhibitory activities against EGFR^WT and EGFR^T790M with IC₅₀ values of 0.099 and 0.123 µM, respectively. In addition, it arrested the cell cycle at pre-G1 phase and induced a significant apoptotic effect in PC-3 cells. Furthermore, compound 8a induced a 5.3-fold increase in the level of caspase-3 in PC-3 cells. Finally, docking studies were carried out to examine the binding mode of the synthesised compounds against both EGFR^WT and EGFR^T790M.

Design, synthesis and molecular docking of new fused 1H-pyrroles, pyrrolo[3,2-d]pyrimidines and pyrrolo[3,2-e][1, 4]diazepine derivatives as potent EGFR/CDK2 inhibitors

A new series of 1H-pyrrole (6a-c, 8a-c), pyrrolo[3,2-d]pyrimidines (9a-c) and pyrrolo[3,2-e][1, 4]diazepines (11a-c) were designed and synthesised. These compounds were designed to have the essential pharmacophoric features of EGFR Inhibitors, they have shown anticancer activities against HCT116, MCF-7 and Hep3B cancer cells with IC₅₀ values ranging from 0.009 to 2.195 µM. IC₅₀ value of doxorubicin is 0.008 µM, compounds 9a and 9c showed IC₅₀ values of 0.011 and 0.009 µM respectively against HCT-116 cells. Compound 8b exerted broad-spectrum activity against all tested cell lines with an IC₅₀ value less than 0.05 µM. Compound 8b was evaluated against a panel of kinases. This compound potently inhibited CDK2/Cyclin A1, DYRK3 and GSK3 alpha kinases with 10-23% compared to imatinib (1-10%). It has also arrested the cell cycle of MCF-7 cells at the S phase. Its antiproliferative activity was further augmented by molecular docking into the active sites of EGFR and CDK2 cyclin A1.

Discovery of new 1H-pyrazolo[3,4-d]pyrimidine derivatives as anticancer agents targeting EGFRWT and EGFRT790M

New 1H-pyrazolo[3,4-d]pyrimidine derivatives were designed and synthesised to act as epidermal growth factor receptor inhibitors (EGFRIs). The synthesised derivatives were assessed for their in vitro anti-proliferative activities against A549 and HCT-116 cancer cells. Compounds 8, 10, 12a, and 12b showed potent anti-proliferative activities. Compound 12b was the most promising member with IC50 values of 8.21 and 19.56 µM against A549 and HCT-116, respectively. Compounds 8, 10, 12a, and 12b were evaluated for their kinase inhibitory activities against wild EGFR (EGFRWT). Compound 12b was the most potent member showing an IC50 value of 0.016 µM. In addition, compound 12b showed noticeable activity against mutant EGFR (EGFRT790M) (IC50 = 0.236 µM). Flow cytometric analyses revealed that compound 12b is a good apoptotic inducer and can arrest the cell cycle at S and G2/M phases. Furthermore, it produced an 8.8-fold increase in BAX/Bcl-2 ratio. Molecular docking studies were carried out against EGFRWT and EGFRT790M.

A New Theobromine-Based EGFRWT and EGFRT790M Inhibitor and Apoptosis Inducer: Design, Semi-Synthesis, Docking, DFT, MD Simulations, and In Vitro Studies

The essential pharmacophoric structural properties were applied to design a new derivative of theobromine as an antiangiogenic EGFR inhibitor. The designed candidate is a (para-nitrophenyl)acetamide derivative of the natural alkaloid, theobromine (T-2-PNPA). The potentialities of T-2-PNPA to inhibit the EGFR protein were studied computationally in an extensive way. Firstly, the molecular docking against EGFRWT and EGFRT790M demonstrated T-2-PNPA’s capabilities of binding with the targeted receptors. Then, the MD experiments (for 100 ns) illustrated through six different studies the changes that occurred in the energy as well as in the structure of EGFR–T-2-PNPA complex. Additionally, an MM-GBSA analysis determined the exact energy of binding and the essential residues. Furthermore, DFT calculations investigated the stability, reactivity, and electrostatic potential of T-2-PNPA. Finally, ADMET and toxicity studies confirmed both the safety as well as the general likeness of T-2-PNPA. Consequently, T-2-PNPA was prepared for the in vitro biological studies. T-2-PNPA inhibited EGFRWT and EGFRT790M with IC50 values of 7.05 and 126.20 nM, respectively, which is comparable with erlotinib activities (5.91 and 202.40, respectively). Interestingly, T-2-PNPA expressed cytotoxic potentialities against A549 and HCT-116 cells with IC50 values of 11.09 and 21.01 µM, respectively, which is again comparable with erlotinib activities (6.73 and 16.35, respectively). T-2-PNPA was much safer against WI-38 (IC50 = 48.06 µM) than erlotinib (IC50 = 31.17 µM). The calculated selectivity indices of T-2-PNPA against A549 and HCT-116 cells were 4.3 and 2.3, respectively. This manuscript presents a new lead anticancer compound (T-2-PNPA) that has been synthesized for the first time and exhibited promising in silico and in vitro anticancer potentialities.

New Anticancer Theobromine Derivative Targeting EGFRWT and EGFRT790M: Design, Semi-Synthesis, In Silico, and In Vitro Anticancer Studies

Based on the pharmacophoric features of EGFR inhibitors, a new semisynthetic theobromine-derived compound was designed to interact with the catalytic pocket of EGFR. Molecular docking against wild (EGFR^WT; PDB: 4HJO) and mutant (EGFR^T790M; PDB: 3W2O) types of EGFR-TK indicated that the designed theobromine derivative had the potential to bind to that pocket as an antiangiogenic inhibitor. The MD and MM-GBSA experiments identified the exact binding with optimum energy and dynamics. Additionally, the DFT calculations studied electrostatic potential, stability, and total electron density of the designed theobromine derivative. Both in silico ADMET and toxicity analyses demonstrated its general likeness and safety. We synthesized the designed theobromine derivative (compound XI) which showed an IC₅₀ value of 17.23 nM for EGFR inhibition besides IC₅₀ values of 21.99 and 22.02 µM for its cytotoxicity against A549 and HCT-116 cell lines, respectively. Interestingly, compound XI expressed a weak cytotoxic potential against the healthy W138 cell line (IC₅₀ = 49.44 µM, 1.6 times safer than erlotinib), exhibiting the high selectivity index of 2.2. Compound XI arrested the growth of A549 at the G2/M stage and increased the incidence of apoptosis.

Design, synthesis, in vitro biological assessment and molecular modeling insights for novel 3-(naphthalen-1-yl)-4,5-dihydropyrazoles as anticancer agents with potential EGFR inhibitory activity

Currently, the humanity is in a fierce battle against various health-related challenges especially those associated with human malignancies. This created the urge to develop potent and selective inhibitors for tumor cells through targeting specific oncogenic proteins possessing crucial roles in cancer progression and survive. In this respect, new series of pyrazole-thiazol-4-one hybrids (9a–p) were synthesized as potential anticancer agents. All the synthesized molecules exhibited potent antiproliferative actions against breast cancer (BC) T-47D and MDA-MB-231 cell lines with IC₅₀ ranges 3.14–4.92 and 0.62–58.01, respectively. Moreover, the most potent anti-proliferative counterparts 9g and 9k were assessed against EGFR. They displayed nanomolar inhibitory activity, IC₅₀ 267 ± 12 and 395 ± 17 nM, respectively. Worth noting, both compounds 9g and 9k induced apoptosis in MDA-MB-231 cells, and resulted in a cell cycle arrest at G2/M phase. Furthermore, an in silico analysis including docking and molecular dynamic simulations was performed.

Nanogel-mediated drug delivery system for anticancer agent: pH stimuli responsive poly(ethylene glycol/acrylic acid) nanogel prepared by gamma irradiation

The popularity of nanogel as nano drug carrier lies in its adjustable physical properties, and the ability to encapsulate drug particles with improved properties is being developed to meet the diverse pH-sensitive nanogel for anticancer agent. Monitoring pH has been identified as an important diagnostic element during the treatment process. A pH-sensitive nanogel consisting of (PEG/PMAc) in the ratio of (50:50%) hasbeen cross-linkedby γ-irradiation techniques at an irradiation dose of 5 kGy. Compound 4 and its nanogel 5 were synthesized and assessed for their anticancer effects against HepG2, A549, MCF-7 and HCT-116 as dual VEGFR-2 and EGFR tyrosine kinases inhibitors. The molecular design was performed to investigate the binding mode of compound 4 with VEGFR-2 and EGFR receptors. Our compound 5 in nanogel showed enhanced anticancer activities against the four tested cancer cell lines and also showed higher inhibition activities against VEGFR-2 and EGFR^T790M kinases than the derivative 4. Finally, our derivative 4 showed good in silico calculated ADMET profile. It was expected to show good GIT absorption in human, lower CNS side effects, no hepatotoxic actions and higher acute and oral chronic toxic doses in comparing to sorafenib and erlotinib. The obtained results showed that, our compound could be useful as a template for future design, optimization, adaptation and investigation to produce more potent and selective dual VEGFR-2/EGFR^T790M inhibitors with higher anticancer activity.

New phthalimide-based derivatives as EGFR-TK inhibitors: Synthesis, biological evaluation, and molecular modeling study

A novel series of phthalimide derivatives was synthesized and evaluated for in vitro antitumor activity against six human cancer cell lines; HepG-2, HCT-116, MCF-7, Hep2, PC3 and Hela.The obtained results revealed that compound 32 was the most potent antitumor, while compounds 33, 22 and 24 showed strong activity against all tested cell lines. Further biological evaluation of the most active compounds was done and their in vitro EGFR-TK inhibition was tested, and the results came in accordance with the results of antitumor testing, where 32 displayed promising inhibitory activity (IC₅₀ = 0.065 µM) compared to the standard drug erlotinib (IC₅₀ = 0.067 µM). In addition, compounds 48, 22, 28 and 19 showed strong inhibitory activity (IC₅₀ = 0.089, 0.093, 0.147 and 0.152 µM respectively). Cell cycle analysis was conducted and the results revealed that 32 induced cell cycle arrest on Hela and MCF-7 at G0-G1 phase and Pre-G1 phase causing cell death mainly via apoptosis. Additionally, in vivo antitumor screening revealed that 32 reduced both body weight and tumor volume in solid tumor utilizing Ehrlich ascites carcinoma (EAC) animal model. Molecular modeling study showed that 32 and 48 have the highest affinity for binding with the active site of EGFR-TK with docking score comparable to erlotinib. Compounds 32 and 48 could be used as template models for further optimization.

Design, synthesis, in silico docking, ADMET and anticancer evaluations of thiazolidine-2,4-diones bearing heterocyclic rings as dual VEGFR-2/EGFRT790M tyrosine kinase inhibitors

Fourteen recent thiazolidine-2,4-diones bearing furan and/or thiophene heterocyclic rings have been designed, synthesized and assessed for their anticancer activities against four human tumor cell lines HepG2, A549, MCF-7 and HCT-116 targeting both VEGFR-2 and EGFR tyrosine kinases. Molecular design was carried out to investigate the binding mode of the proposed compounds with VEGFR-2 and EGFR receptors. HepG2 was the most susceptible cell line to the influence of our derivatives. Compounds 5g and 4g revealed the highest activities against HepG2 (IC₅₀ = 3.86 and 6.22 μM), A549 (IC₅₀ = 7.55 and 12.92 μM), MCF-7 (IC₅₀ = 10.65 and 10.66 μM) and HCT116 (IC₅₀ = 9.04 and 11.17 μM) tumor cell lines. Sorafenib (IC₅₀ = 4.00, 4.04, 5.58 and 5.05 μM) and elotinib (IC₅₀ = 7.73, 5.49, 8.20 and 13.91 μM) were used as reference standards. Furthermore, the most active cytotoxic compounds 4d, 4e, 4f, 4g, 5d, 5e, 5f and 5g were selected to assess their VEGFR-2 inhibitory effects. Derivatives 5g, 4g and 4f were observed to be the highest effective derivatives that inhibited VEGFR-2 at the submicromolar level (IC₅₀ = 0.080, 0.083 and 0.095 μM respectively) in comparison to sorafenib (IC₅₀ = 0.084 μM). As well, compounds 4d, 4e, 4f, 4g, 5d, 5e, 5f and 5g were additionally assessed for their inhibitory activities against mutant EGFR^T790M. Compounds 5g and 4g could interfere with the EGFR^T790M activity exhibiting stronger activities than elotinib with IC₅₀ = 0.14 and 0.23 μM respectively. Finally, our derivatives 4g, 5f and 5g showed a good in silico calculated ADMET profile. The obtained results showed that our compounds could be useful as a template for future design, optimization, adaptation and investigation to produce more potent and selective dual VEGFR-2/EGFR^T790M inhibitors with higher anticancer activity.

New pyrimidine-5-carbonitrile derivatives as EGFR inhibitors with anticancer and apoptotic activity: Design, molecular modeling and synthesis

In connection with our efforts on the development of new anticancer agents, herein we report the design and synthesis of new small pyrimidine-5-carbonitrile based derivatives. The target pyrimidines were evaluated...

Quinoline–hydrazone hybrids as dual mutant EGFR inhibitors with promising metallic nanoparticle loading: rationalized design, synthesis, biological investigation and computational studies

A novel quinoline–hydrazone hybrid induced apoptosis in MCF-7 cells through dual mutant EGFR inhibition with promising metallic nanoparticle loading.

Discovery of a Novel Template, 7-Substituted 7-Deaza-4'-Thioadenosine Derivatives as Multi-Kinase Inhibitors

The development of anticancer drugs remains challenging owing to the potential for drug resistance. The simultaneous inhibition of multiple targets involved in cancer could overcome resistance, and these agents would exhibit higher potency than single-target inhibitors. Protein kinases represent a promising target for the development of anticancer agents. As most multi-kinase inhibitors are heterocycles occupying only the hinge and hydrophobic region in the ATP binding site, we aimed to design multi-kinase inhibitors that would occupy the ribose pocket, along with the hinge and hydrophobic region, based on ATP-kinase interactions. Herein, we report the discovery of a novel 4'-thionucleoside template as a multi-kinase inhibitor with potent anticancer activity. The in vitro evaluation revealed a lead 1g (7-acetylene-7-deaza-4'-thioadenosine) with potent anticancer activity, and marked inhibition of TRKA, CK1δ, and DYRK1A/1B kinases in the kinome scan assay. We believe that these findings will pave the way for developing anticancer drugs.

Tyrosine kinase inhibitor prodrug-loaded liposomes for controlled release at tumor microenvironment

Tyrosine kinase inhibitors (TKIs) represent one of the most advanced class of therapeutics for cancer treatment. Most of them are also cytochrome P450 (CYP) inhibitors and/or substrates thereof. Accordingly, their efficacy and/or toxicity can be affected by CYP-mediated metabolism and by metabolism-derived drug-drug interactions. In order to enhance the therapeutic performance of these drugs, we developed a prodrug (Pro962) of our TKI TK962 specifically designed for liposome loading and pH-controlled release in the tumor. A cholesterol moiety was linked to TK962 through pH-sensitive hydrazone bond for anchoring to the liposome phospholipid bilayer to prevent leakage of the prodrug from the nanocarrier. Bioactivity studies performed on isolated target kinases showed that the prodrug maintains only partial activity against them and the release of TK962 is required. Biopharmaceutical studies carried out with prodrug loaded liposomes showed that the prodrug was firmly associated with the vesicles and the drug release was prevented under blood-mimicking conditions. Conversely, conventional liposome loaded with TK962 readily released the drug. Flow cytometric studies showed that liposomes efficiently provided for intracellular prodrug delivery. The use of the hydrazone linker yielded a pH-controlled drug release, which resulted in about 50% drug release at pH 4 and 5 in 2 h. Prodrug, prodrug loaded liposomes and active lead compound have been tested against cancer cell lines in either 2D or 3D models. The liposome formulation showed higher cytotoxicity than the unformulated lead TK962 in both 2D and 3D models. The stability of prodrug, prodrug loaded liposomes and active lead compound in human serum and against human, mouse, and rat microsomes was also assessed, demonstrating that liposome formulations impair the metabolic reactions and protect the loaded compounds from catabolism. The results suggest that the liposomal formulation of pH releasable TKI prodrugs is a promising strategy to improve the metabolic stability, intracellular cancer cell delivery and release, and in turn the efficacy of this class of anticancer drugs.

Design, Synthesis, biological Evaluation, and molecular docking studies of novel Pyrazolo[3,4-d]Pyrimidine derivative scaffolds as potent EGFR inhibitors and cell apoptosis inducers

A series of novel hybrid pyrazolo[3,4-d]pyramidine derivatives was designed and chemically synthesized in useful yields. The synthesized compounds were structurally characterized by the usual techniques. All the new synthesized compounds were biologically screened in vitro for their antiproliferative activities against a panel of four cancer cell lines, namely HepG-2, MCF-7, HCT-116, and Hela. The results of cytotoxic evaluation indicated that compound 14d was appeared to be the most prominent broad-spectrum cytotoxic activity and significantly more potent than sorafenib with IC₅₀ values of 4.28, 5.18, 3.97, and 9.85 µM against four cell lines (HePG2, Hela, HCT-116 and MCF-7). In addition, compound 15 was displayed promising antiproliferative effect against all tested cell lines with IC₅₀ value less than 11 µM compared with sorafenib as a control drug. Besides, structurally pharmacophoric features indicated that pyrazolo[3,4-d]pyrimidine scaffold having an amide linker and substituted with phenyl moiety at the 5-position was more potent than those possessing azomethine methyl, azomethine proton and carbomethene linkers, which lead to significant decrease in antiproliferative activity. The most potent compounds were further selected and evaluated for their activities against epidermal growth factor receptor (EGFR) kinase inhibitors according to homogenous time resolved fluorescence (HTRF) assay. The most potent compound 14d exhibited the most promising inhibitory activity against EGFR^WT with IC₅₀ value of 56.02 ± 1.38 µM compared with gefitinib as control drug with IC₅₀ value of 41.79 ± 1.07 µM. Moreover, the inhibition of cell cycle progression and induction of apoptosis in the A549 cell line at G2/M and pre-G1 phases of cell cycle might contribute to cancer treatment that evaluated by Annexin V-FITC/PI double staining detection method. Finally, molecular docking studies were conducted to investigate that probable binding conformations of these anticancer agents and ADME properties were calculated to predict pharmacokinetics and toxic properties of the target compounds.

EGFRisopred: a machine learning-based classification model for identifying isoform-specific inhibitors against EGFR and HER2

The EGFR kinase pathway is one of the most frequently activated signaling pathways in human cancers. EGFR and HER2 are the two significant members of this pathway, which are attractive drug targets of clinical relevance in lung and breast cancer. Therefore, identifying EGFR- and HER2-specific inhibitors is one of the important challenges in cancer drug discovery. To address this issue, a dataset of 519 compounds having inhibitory activity against both the isoforms, i.e., EGFR and HER2, was collected from the literature and developed a knowledge-based computational classification model for predicting the specificity of a molecule for an isoform (EGFR/HER2) with precision. A total of seventy-two classification models using nine fingerprint types, four classifiers (IBK, NB, SMO and RF) and two different datasets (EGFR and HER2 isoform specific) were developed. It was observed that the models developed using random forest and IBK performed better for EGFR- and HER2-specific datasets, respectively. Scaffold and functional group analysis led to the identification of prevalent core and fragments in each of the datasets. The accuracy of the selected best performing models was also evaluated using the decoy dataset. We have also developed an application EGFRisopred, which integrates the best performing models and permits the user to predict the specificity of a compound as an EGFR-/HER2-specific anticancer agent. It is expected that the tool's availability as a free utility will allow researchers to identify new inhibitors against these targets important in cancer.

Recent advances in urea- and thiourea-containing compounds: focus on innovative approaches in medicinal chemistry and organic synthesis

Urea and thiourea represent privileged structures in medicinal chemistry. Indeed, these moieties constitute a common framework of a variety of drugs and bioactive compounds endowed with a broad range of therapeutic and pharmacological properties. Herein, we provide an overview of the state-of-the-art of urea and thiourea-containing pharmaceuticals. We also review the diverse approaches pursued for (thio)urea bioisosteric replacements in medicinal chemistry applications. Finally, representative examples of recent advances in the synthesis of urea- and thiourea-based compounds by enabling chemical tools are discussed.

Design, synthesis and biological evaluation of 2,3-dihydro-[1,4]dioxino[2,3-f]quinazoline derivatives as EGFR inhibitors

Epidermal growth factor receptor (EGFR) is the most attractive target for drug research in non-small cell lung cancer (NSCLC). The first-generation EGFR tyrosine kinase inhibitors (TKIs) Gefetinib and Elotinib showed good clinical efficacy on lung adenocarcinoma tumors, but almost all patients developed resistance to these inhibitors over time. Quinazoline and quinoline derivatives are common targeted inhibitors of EGFR kinase, and their structural optimization is an important direction for the development of effective targeted anticancer drugs. Based on these facts, a series of heterocyclic 2,3-dihydro-[1,4]dioxino[2,3-f]quinazoline derivatives have been designed and synthesized and their structures were confirmed by spectral analyses. The cytotoxic activity of the newly synthesized compounds was evaluated against the human kidney epithelial T293 cell line, normal lung cell lines WI-38, non-small cell lung cancer A549 and NCI-H157 cell lines using MTT. The tested compounds showed an evident anticancer activity against the tested cell lines, especially compound 13c, which was the most potent anticancer agent with half maximal inhibitory concentrations (IC₅₀) between 8.82 and 10.24 μM. Docking study showed that compound 13b could be nicely bound to the ATP binding pocket of EGFR. In addition, the inhibitory activity of the target compounds against epidermal growth factor receptor tyrosine kinase (EGFR-TK) was evaluated. Results indicated the ability of the target compounds to inhibit EGFR-TK with half maximal inhibitory concentrations (IC₅₀) in the range of 10.29 nM to 652.3 nM. In view of the reported compound activity, the structure deserves further optimization as cancer treatment agents.

Recent developments of RET protein kinase inhibitors with diverse scaffolds as hinge binders

RET is a proto-oncogene encoding a receptor tyrosine kinase. RET regulates key aspects of cellular proliferation, differentiation and survival. The activation of RET via gene fusions or point mutations is closely related to lung, thyroid and other cancers. This review summarizes the developments of a diversity of small molecule RET protein kinase inhibitors in the past 10 years. These RET inhibitors are classified according to their hinge binder chemotypes as: pyrimidines, including the pyrazolopyrimidines, pyrimidine oxazines, quinazolines, 4-aminopyrimidines and 4-aminopyridines; indolinones; 5-aminopyrazole-4-carboxamides; 3-trifluoromethylanilines; imidazopyridines, imidazopyridazines and pyrazopyridines; nicotinonitriles; pyridones and 1,2,4-triazoles. In each section, the biological activities of the inhibitors, their structure-activity relationships and possible binding modes with the RET kinase are introduced.

Clinically Precedented Protein Kinases: Rationale for Their Use in Neurodegenerative Disease

Kinases are an intensively studied drug target class in current pharmacological research as evidenced by the large number of kinase inhibitors being assessed in clinical trials. Kinase-targeted therapies have potential for treatment of a broad array of indications including central nervous system (CNS) disorders. In addition to the many variables which contribute to identification of a successful therapeutic molecule, drug discovery for CNS-related disorders also requires significant consideration of access to the target organ and specifically crossing the blood-brain barrier (BBB). To date, only a small number of kinase inhibitors have been reported that are specifically designed to be BBB permeable, which nonetheless demonstrates the potential for success. This review considers the potential for kinase inhibitors in the context of unmet medical need for neurodegenerative disease. A subset of kinases that have been the focus of clinical investigations over a 10-year period have been identified and discussed individually. For each kinase target, the data underpinning the validity of each in the context of neurodegenerative disease is critically evaluated. Selected molecules for each kinase are identified with information on modality, binding site and CNS penetrance, if known. Current clinical development in neurodegenerative disease are summarized. Collectively, the review indicates that kinase targets with sufficient rationale warrant careful design approaches with an emphasis on improving brain penetrance and selectivity.

Discovery of new pyrimidine-5-carbonitrile derivatives as anticancer agents targeting EGFRWT and EGFRT790M

A new series of pyrimidine-5-carbonitrile derivatives has been designed as ATP mimicking tyrosine kinase inhibitors of the epidermal growth factor receptor (EGFR). These compounds were synthesized and evaluated for their in vitro cytotoxic activities against a panel of four human tumor cell lines, namely colorectal carcinoma (HCT-116), hepatocellular carcinoma (HepG-2), breast cancer (MCF-7), and non-small cell lung cancer cells (A549). Five of the synthesized compounds, 11a, 11b, 12b, 15b and 16a, were found to exhibit moderate antiproliferative activity against the tested cell lines and were more active than the EGFR inhibitor erlotinib. In particular, compound 11b showed 4.5- to 8.4-fold erlotinib activity against HCT-116, HepG-2, MCF-7, and A549 cells with IC50 values of 3.37, 3.04, 4.14, and 2.4 μM respectively. Moreover, the most cytotoxic compounds that showed promising IC50 values against the four cancer cell lines were subjected to further investigation for their kinase inhibitory activities against EGFRWT and EGFRT790M using homogeneous time resolved fluorescence (HTRF) assay. Compound 11b was also found to be the most active compound against both EGFRWT and mutant EGFRT790M, exhibiting IC50 values of 0.09 and 4.03 μM, respectively. The cell cycle and apoptosis analyses revealed that compound 11b can arrest the cell cycle at the G2/M phase and induce significant apoptotic effects in HCT-116, HepG-2, and MCF-7 cells. Additionally, compound 11b upregulated the level of caspase-3 by 6.5 fold in HepG-2 when compared with the control. Finally, molecular docking studies were carried out to examine the binding mode of the synthesized compounds against the proposed targets; EGFRWT and EGFRT790M. Additional in silico ADMET studies were performed to explore drug-likeness properties.

Cytotoxic Activity and DNA Binding Property of New Aminopyrimidine Derivatives

Background:

Chromene and anilinopyrimidine heterocyclics are attractive anticancer compounds that have inspired many researchers to design novel derivatives bearing improved anticancer activity.

Methods:

A series of pyrimidine-fused benzo[f]chromene derivatives 6a-x were synthesized as anticancer hybrids of 1H-benzo[f]chromenes and anilinopyrimidines. The inhibitory activity of the synthesized compounds 6a-x against cell viability of human chronic myelogenous leukemia (K562), human acute lymphoblastic leukemia (MOLT-4) and human breast adenocarcinoma (MCF-7) cell lines was evaluated using MTT assay. The interaction of the most promising compound with calf-thymus DNA was also studied using spectrometric titrations and Circular Dichroism (CD) spectroscopy.

Results:

Most compounds showed promising activity against tested cell lines. Among them, 2,4- dimethoxyanilino derivative 6g exhibited the best profile of activity against tested cell lines (IC50s = 1.6-6.1 μM) with no toxicity against NIH3T3 normal cell (IC50 >200 μM). The spectrometric studies exhibited that compound 6g binds to DNA strongly and may change DNA conformation significantly, presumably via a groove binding mechanism.

Conclusion:

The results of this study suggest that the prototype compound 6g can be considered as a novel lead compound for the design and discovery of novel anticancer agents.

Synthesis and In Vitro Antiproliferative Activity of New 1-Phenyl-3-(4-(pyridin-3-yl)phenyl)urea Scaffold-Based Compounds

A new series of 1-phenyl-3-(4-(pyridin-3-yl)phenyl)urea derivatives were synthesized and subjected to in vitro antiproliferative screening against National Cancer Institute (NCI)-60 human cancer cell lines of nine different cancer types. Fourteen compounds 5a–n were synthesized with three different solvent exposure moieties (4-hydroxylmethylpiperidinyl and trimethoxyphenyloxy and 4-hydroxyethylpiperazine) attached to the core structure. Substituents with different π and σ values were added on the terminal phenyl group. Compounds 5a–e with a 4-hydroxymethylpiperidine moiety showed broad-spectrum antiproliferative activity with higher mean percentage inhibition values over the 60-cell line panel at 10 µM concentration. Compound 5a elicited lethal rather than inhibition effects on SK-MEL-5 melanoma cell line, 786-0, A498, RXF 393 renal cancer cell lines, and MDA-MB-468 breast cancer cell line. Two compounds, 5a and 5d showed promising mean growth inhibitions and thus were further tested at five-dose mode to determine median inhibitory concentration (IC₅₀) values. The data revealed that urea compounds 5a and 5d are the most active derivatives, with significant efficacies and superior potencies than paclitaxel in 21 different cancer cell lines belonging particularly to renal cancer and melanoma cell lines. Moreover, 5a and 5d had superior potencies than gefitinib in 38 and 34 cancer cell lines, respectively, particularly colon cancer, breast cancer and melanoma cell lines.

Hit discovery of 4-amino-N-(4-(3-(trifluoromethyl)phenoxy)pyrimidin-5-yl)benzamide: A novel EGFR inhibitor from a designed small library

Searching for hit compounds within the huge chemical space resembles the attempt to find a needle in a haystack. Cheminformatics-guided selection of few representative molecules of a rationally designed virtual combinatorial library is a powerful tool to confront this challenge, speed up hit identification and cut off costs. Herein, this approach has been applied to identify hit compounds with novel scaffolds able to inhibit EGFR kinase. From a generated virtual library, six 4-aryloxy-5-aminopyrimidine scaffold-derived compounds were selected, synthesized and evaluated as hit EGFR inhibitors. 4-Aryloxy-5-benzamidopyrimidines inhibited EGFR with IC₅₀ 1.05-5.37 μM. Cell-based assay of the most potent EGFR inhibitor hit (10ac) confirmed its cytotoxicity against different cancerous cells. In spite of no EGFR, HER2 or VEGFR1 inhibition was elicited by 4-aryloxy-5-(thio)ureidopyrimidine derivatives, cell-based evaluation suggested them as antiproliferative hits acting by other mechanism(s). Molecular docking study provided a plausible explanation of incapability of 4-aryloxy-5-(thio)ureidopyrimidines to inhibit EGFR and suggested a reasonable binding mode of 4-aryloxy-5-benzamidopyrimidines which provides a basis to develop more optimized ligands.

Discovery of wt RET and V804M RET Inhibitors: From Hit to Lead

Oncogenic activation of RET kinase has been found in several neoplastic diseases, like medullary thyroid carcinoma, multiple endocrine neoplasia, papillary thyroid carcinoma, and non-small-cell lung cancer. Currently approved RET inhibitors were not originally designed to be RET inhibitors, and their potency against RET kinase has not been optimized. Hence, novel compounds able to inhibit both wild-type RET (^wt RET) and its mutants (e.g., ^V804M RET) are needed. Herein we present the development and the preliminary evaluation of a new sub-micromolar ^wt RET/^V804M RET inhibitor, N-(2-fluoro-5-trifluoromethylphenyl)-N'-{4'-[(2''-benzamido)pyridin-4''-ylamino]phenyl}urea (69), endowed with a 4-anilinopyridine structure, starting from our previously identified 4-anilinopyrimidine hit compound. Profiling against a panel of kinases indicated 69 as a multi cKIT/^wt RET/^V804M RET inhibitor.