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

Rationale design of novel substituted 1,3,5-triazine candidates as dual IDH1(R132H)/ IDH2(R140Q) inhibitors with high selectivity against acute myeloid leukemia: In vitro and in vivo preclinical investigations

In this study, novel substituted 1,3,5-triazine candidates (4a-d, 5a-j, and 6a-d) were designed as second-generation small molecules to act as dual IDH1 and IDH2 inhibitors according to the pharmacophoric features of both vorasidenib and enasidenib. Compounds 6a and 6b for leukemia cell lines showed from low to sub-micromolar GI50. Moreover, compounds 4c, 5f, and 6b described the frontier antitumor activity against THP1 and Kasumi Leukemia cancer cells with IC50 values of (10 and 12), (10.5 and 7), and (6.2 and 5.9) µg/mL, which were superior to those of cisplatin (25 and 28) µg/mL, respectively. Interestingly, compounds 4c, 6b, and 6d represented the best dual IDH1(R132H)/IDH2(R140Q) inhibitory potentials with IC50 values of (0.72 and 1.22), (0.12 and 0.93), and (0.50 and 1.28) µg/mL, respectively, compared to vorasidenib (0.02 and 0.08) µg/mL and enasidenib (0.33 and 1.80) µg/mL. Furthermore, the most active candidate (6b) has very promising inhibitory potentials towards HIF-1α, VEGF, and SDH, besides, a marked increase of ROS was observed as well. Besides, compound 6b induced the upregulation of P53, BAX, Caspases 3, 6, 8, and 9 proteins by 3.70, 1.99, 2.06, 1.73, 1.75, and 1.85-fold changes, respectively, and the downregulation for the BCL-2 protein by 0.55-fold change compared to the control. Besides, the in vivo behavior of compound 6b as an antitumor agent was evaluated in female mice bearing solid Ehrlich carcinoma tumors. Notably, compound 6b administration resulted in a prominent decrease in the weight and volume of the tumors, accompanied by improvements in biochemical, hematological, and histological parameters.

Design and synthesis of novel tetrabromophthalimide derivatives as potential tubulin inhibitors endowed with apoptotic induction for cancer treatment

Although various approaches exist for treating cancer, chemotherapy continues to hold a prominent role in the management of this disease. Besides, microtubules serve as a vital component of the cellular skeleton, playing a pivotal role in the process of cell division making it an attractive target for cancer treatment. Hence, the scope of this work was adapted to design and synthesize new anti-tubulin tetrabromophthalimide hybrids (3-17) with colchicine binding site (CBS) inhibitory potential. The conducted in vitro studies showed that compound 16 displayed the lowest IC50 values (11.46 µM) at the FaDu cancer cell lines, whereas compound 17 exhibited the lowest IC50 value (13.62 µM) at the PC3 cancer cell line. However, compound 7b exhibited the lowest IC50 value (11.45 µM) at the MDA-MB-468 cancer cell line. Moreover, compound 17 was observed to be the superior antitumor candidate against all three tested cancer cell lines (MDA-MB-468, PC3, and FaDu) with IC50 values of 17.22, 13.15, and 13.62 µM, respectively. In addition, compound 17 showed a well-established upregulation of apoptotic markers (Caspases 3, 7, 8, and 9, Bax, and P53). Moreover, compound 17 induced downregulation of the antiapoptotic markers (MMP2, MMP9, and BCL-2). Furthermore, the colchicine binding site inhibition assay showed that compounds 15a and 17 exhibited particularly significant inhibitory potentials, with IC50 values of 23.07 and 4.25 µM, respectively, compared to colchicine, which had an IC50 value of 3.89 µM. Additionally, cell cycle analysis was conducted, showing that compound 17 could prompt cell cycle arrest at both the G0-G1 and G2-M phases. On the other hand, a molecular docking approach was applied to investigate the binding interactions of the examined candidates compared to colchicine towards CBS of the β-tubulin subunit. Thus, the synthesized tetrabromophthalimide hybrids can be regarded as outstanding anticancer candidates with significant apoptotic activity.

Discovery of novel benzimidazole derivatives as potent HDACs inhibitors against leukemia with (Thio)Hydantoin as zinc-binding moiety: Design, synthesis, enzyme inhibition, and cellular mechanistic study

Based on the well-established pharmacophoric features required for histone deacetylase (HDAC) inhibition, a novel series of easy-to-synthesize benzimidazole-linked (thio)hydantoin derivatives was designed and synthesized as HDAC6 inhibitors. All target compounds potently inhibited HDAC6 at nanomolar levels with compounds 2c, 2d, 4b and 4c (IC50s = 51.84-74.36 nM) being more potent than SAHA reference drug (IC50 = 91.73 nM). Additionally, the most potent derivatives were further assessed for their in vitro cytotoxic activity against two human leukemia cells. Hydantoin derivative 4c was equipotent/superior to SAHA against MOLT-4/CCRF-CEM leukemia cells, respectively and demonstrated safety profile better than that of SAHA against non-cancerous human cells. 4c was also screened against different HDAC isoforms. 4c was superior to SAHA against HDAC1. Cell-based assessment of 4c revealed a significant cell cycle arrest and apoptosis induction. Moreover, western blotting analysis showed increased levels of acetylated histone H3, histone H4 and α-tubulin in CCRF-CEM cells. Furthermore, docking study exposed the ability of title compounds to chelate Zn2+ located within HDAC6 active site. As well, in-silico evaluation of physicochemical properties showed that target compounds are promising candidates in terms of pharmacokinetic aspects.

N- and s-substituted Pyrazolopyrimidines: A promising new class of potent c-Src kinase inhibitors with prominent antitumor activity

In this work, readily achievable synthetic pathways were utilized for construction of a library of N/S analogues based on the pyrazolopyrimidine scaffold with terminal alkyl or aryl fragments. Subsequently, we evaluated the anticancer effects of these novel analogs against the proliferation of various cancer cell lines, including breast, colon, and liver lines. The results were striking, most of the tested molecules exhibited strong and selective cytotoxic activity against the MDA-MB-231 cancer cell line; IC50 1.13 µM. Structure-activity relationship (SAR) analysis revealed that N-substituted derivatives generally enhanced the cytotoxic effect, particularly with aliphatic side chains that facilitated favorable target interactions. We also investigated apoptosis, DNA fragmentation, invasion assay, and anti-migration effects, and discussed their underlying molecular mechanisms for the most active compound 7c. We demonstrated that 7c N-propyl analogue could inhibit MDA-MB-231 TNBC cell proliferation by inducing apoptosis through the regulation of vital proteins, namely c-Src, p53, and Bax. In addition, our results also revealed the potential of these compounds against tumor metastasis by downregulating the invasion and migration modes. Moreover, the in vitro inhibitory effect of active analogs against c-Src kinase was studied and proved that might be the main cause of their antiproliferative effect. Overall, these compelling results point towards the therapeutic potential of these derivatives, particularly those with N-substitution as promising candidates for the treatment of TNBC type of breast cancer.

Multi-target rational design and synthesis of novel diphenyl-tethered pyrazolopyrimidines targeting EGFR and topoisomerase II with potential DNA intercalation and apoptosis induction

Herein, we envisioned the design and synthesis of novel pyrazolopyrimidines (confirmed by elemental analysis, 1H and 13C NMR, and mass spectra) as multitarget-directed drug candidates acting as EGFR/TOPO II inhibitors, DNA intercalators, and apoptosis inducers. The target diphenyl-tethered pyrazolopyrimidines were synthesized starting from the reaction of phenyl hydrazine and ethoxymethylenemalononitrile to give aminopyrazole-carbonitrile 2. The latter hydrolysis with NaOH and subsequent reaction with 4-chlorobenzaldhyde afforded the corresponding pyrazolo[3,4-d]pyrimidin-4-ol 4. Chlorination of 4 with POCl3 and sequential reaction with different amines afforded the target compounds in good yields (up to 73 %). The growth inhibition % of the new derivatives (6a-m) was investigated against different cancer and normal cells and the IC50 values of the most promising candidates were estimated for HNO97, MDA-MB-468, FaDu, and HeLa cancer cells. The frontier derivatives (6a, 6i, 6k, 6l, and 6m) were pursued for their EGFR inhibitory activity. Compound 6l decreased EGFR protein concentration by a 6.10-fold change, compared to imatinib as a reference standard. On the other side, compounds (6a, 6i, 6k, 6l, and 6m) underwent topoisomerase II (TOPO II) inhibitory assay. In particular, compounds 6a and 6l exhibited IC50s of 17.89 and 19.39 μM, respectively, surpassing etoposide with IC50 of 20.82 μM. Besides, the DNA fragmentation images described the great potential of both candidates 6a and 6l in inducing DNA degradation at lower concentrations compared to etoposide and doxorubicin. Moreover, compound 6l, with the most promising EGFR/TOPO II inhibition and DNA intercalation, was selected for further investigation for its apoptosis induction ability by measuring caspases 3, 7, 8, and 9, Bax, p53, MMP2, MMP9, and BCL-2 proteins. Additionally, molecular docking was used to explain the SAR results based on the differences in the molecular features of the investigated congeners and the target receptors' topology.

Rational design and eco-friendly one-pot multicomponent synthesis of novel ethylidenehydrazineylthiazol-4(5H)-ones as potential apoptotic inducers targeting wild and mutant EGFR-TK in triple negative breast cancer

A novel series of ethylidenehydrazineylthiazol-4(5H)-ones were synthesized using various eco-friendly one-pot multicomponent synthetic techniques. The anticancer activity of compounds (4a-m) was tested against 11 cancer cell lines. While the IC50 of all compounds was evaluated against the most sensitive cell lines (MDA-MB-468 and FaDu). Our SAR study pinpointed that compound 4a, having a phenyl substituent, exhibited a significant growth inhibition % against all cancer cell lines. The frontier anticancer candidates against the MDA-MB-468 were also examined against the wild EGFR (EGFR-WT) and mutant EGFR (EGFR-T790M) receptors. Most of the synthesized compounds exhibited a higher inhibitory potential against EGFR-T790M than the wild type of EGFR. Remarkably, compound 4k exhibited the highest inhibitory activity against both EGFR-WT and EGFR-T790M with IC50 values (0.051 and 0.021 µM), respectively. The pro-apoptotic protein markers (p53, BAX, caspase 3, caspase 6, caspase 8, and caspase 9) and the anti-apoptotic key marker (BCL-2) were also measured to propose a mechanism of action for the compound 4k as an apoptotic inducer for MDA-MB-468. Investigation of the cell cycle arrest potential of compound 4k was also conducted on MDA-MB-468 cancer cells. We also evaluated the inhibitory activities of compounds (4a-m) against both EGFR-WT and EGFR-T790M using two different molecular docking processes.

Synthesis, photophysical properties, anticancer evaluation, and molecular docking studies of new pyrimidine linked 4-arylidene-thiazolidin-4-ones as potent anticancer agents

The reaction of 4-(chloroacetamido)pyrimidine (1) with ammonium thiocyanate gave 2-(pyrimidin-4-ylimino)thiazolidin-4-one (2), which, when condensed with four substituted benzaldehyde analogues, gave the consequent 5-arylidine-2-(pyrimidin-4-ylimino)thiazolidin-4-ones 3a-d. In addition, the absorbance and fluorescence behaviours of pyrimidinylimino-thiazolidin-4-one hybrids 3a-d in various organic solvents were investigated. The emphasis was on studying UV absorption capacities and the effect of various structural components on photophysical qualities such as the 5-arylidene-2-(pyrimidin-4-ylimino)thiazolidin-4-ones and N,N-dimethylamino tail. The cytotoxic effect of four pyrimidinylimino-thiazolidin-4-one hybrids 3a-d on tumour cell lines (HepG2, HCT-116, PC3, MCF-7) and a normal cell line (WI38) is investigated in this work. The cytotoxicity was measured by comparing the half-maximal inhibitory concentration (IC50 ) to the reference medication, 5-fluorouracil. The findings indicate that these hybrid compounds had varying cytotoxic effects on the cell lines examined; hybrids 3b and 3c demonstrated significant anticancer activity against MCF-7 with IC50 values of 7.53 ± 0.43 and 9.17 ± 0.31 μM, respectively. The inhibitory efficacy of various synthesized hybrids on the epidermal growth factor receptor (EGFR) kinase was investigated. EGFR is a crucial target in cancer treatment because inhibiting it may reduce tumour development and proliferation. The IC50 value was used to calculate the inhibitory activity, which is the concentration of inhibitor necessary to induce half-maximal inhibition of EGFR kinase activity. In addition, the predicted ADME results show that pyrimidinylimino-thiazolidin-4-one hybrids have good pharmacokinetic properties; hybrid 3d is more lipophilic than the other compounds. It has a medium molecular weight, a small number of hydrogen bond acceptors and donors, and a large number of aromatic heavy atoms. Moreover, molecular docking simulations revealed precise information on the interactions of pyrimidinylimino-thiazolidin-4-one hybrids 3a-d and 5-Fu with their respective protein targets. These interactions point to possible pathways for their biological activities and call for more testing to establish their effectiveness as bioactive molecules or therapeutic candidates.

Development of Novel Class of Phenylpyrazolo[3,4-d]pyrimidine-Based Analogs with Potent Anticancer Activity and Multitarget Enzyme Inhibition Supported by Docking Studies

Phenylpyrazolo[3,4-d]pyrimidine is considered a milestone scaffold known to possess various biological activities such as antiparasitic, antifungal, antimicrobial, and antiproliferative activities. In addition, the urgent need for selective and potent novel anticancer agents represents a major route in the drug discovery process. Herein, new aryl analogs were synthesized and evaluated for their anticancer effects on a panel of cancer cell lines: MCF-7, HCT116, and HePG-2. Some of these compounds showed potent cytotoxicity, with variable degrees of potency and cell line selectivity in antiproliferative assays with low resistance. As the analogs carry the pyrazolopyrimidine scaffold, which looks structurally very similar to tyrosine and receptor kinase inhibitors, the potent compounds were evaluated for their inhibitory effects on three essential cancer targets: EGFRWT, EGFRT790M, VGFR2, and Top-II. The data obtained revealed that most of these compounds were potent, with variable degrees of target selectivity and dual EGFR/VGFR2 inhibitors at the IC50 value range, i.e., 0.3-24 µM. Among these, compound 5i was the most potent non-selective dual EGFR/VGFR2 inhibitor, with inhibitory concentrations of 0.3 and 7.60 µM, respectively. When 5i was tested in an MCF-7 model, it effectively inhibited tumor growth, strongly induced cancer cell apoptosis, inhibited cell migration, and suppressed cell cycle progression leading to DNA fragmentation. Molecular docking studies were performed to explore the binding mode and mechanism of such compounds on protein targets and mapped with reference ligands. The results of our studies indicate that the newly discovered phenylpyrazolo[3,4-d]pyrimidine-based multitarget inhibitors have significant potential for anticancer treatment.

Design and synthesis of novel pyrazolopyrimidine candidates as promising EGFR-T790M inhibitors and apoptosis inducers

Aim: Our objective was to design and synthesize a new range of pyrazolopyrimidines while maintaining the key pharmacophoric features of EGFR tyrosine kinase inhibitors. Materials & methods: Percentage inhibition in 14 human cancer cell lines and IC50 values were recorded. Compounds 6c, 7e and 7f were examined against both wild and mutant (T790M) EGFR subtypes. Apoptosis markers, cell cycle arrest, apoptosis assay and molecular docking were performed. Results: Compounds 6c, 7e and 7f demonstrated superior inhibitory potentials against wild and mutant (T790M) EGFR subtypes. A molecular docking study showed that compounds 6c and 7e had the best fit. Conclusion: The designed candidates demonstrated superior inhibitory potential as promising EGFR-T790M inhibitors that agrees with the proposed rationale.

Recent Advances in the Development of Pyrazole Derivatives as Anticancer Agents

Pyrazole derivatives, as a class of heterocyclic compounds, possess unique chemical structures that confer them with a broad spectrum of pharmacological activities. They have been extensively explored for designing potent and selective anticancer agents. In recent years, numerous pyrazole derivatives have been synthesized and evaluated for their anticancer potential against various cancer cell lines. Structure-activity relationship studies have shown that appropriate substitution on different positions of the pyrazole ring can significantly enhance anticancer efficacy and tumor selectivity. It is noteworthy that many pyrazole derivatives have demonstrated multiple mechanisms of anticancer action by interacting with various targets including tubulin, EGFR, CDK, BTK, and DNA. Therefore, this review summarizes the current understanding on the structural features of pyrazole derivatives and their structure-activity relationships with different targets, aiming to facilitate the development of potential pyrazole-based anticancer drugs. We focus on the latest research advances in anticancer activities of pyrazole compounds reported from 2018 to present.

Design, synthesis and biological evaluation of dual Topo II/HDAC inhibitors bearing pyrimido[5,4-b]indole and pyrazolo[3,4-d]pyrimidine motifs

Both topoisomerase II (Topo II) and histone deacetylase (HDAC) are important therapeutic targets for cancer. In this study, two series of novel compounds containing pyrimido[5,4-b]indole and pyrazolo[3,4-d]pyrimidine motifs were designed and synthesized as dual Topo II/HDAC inhibitors. MTT assay indicated that all the compounds displayed potential antiproliferative activity against three cancer cell lines (MGC-803, MCF-7 and U937) and low cytotoxicity on normal cell line (3T3). In the enzyme activity inhibition experiments, compounds 7d and 8d exhibited excellent dual inhibitory activities against Topo II and HDAC. Cleavage reaction assay showed that 7d was a Topo II poison, which was consistent with the docking results. Further experimental results revealed that compounds 7d and 8d could promote apoptosis and significantly inhibit the migration in MCF-7 cells. Molecular docking showed that compounds 7d and 8d bind Topo II and HDAC at the active sites. Molecular dynamics simulation showed that 7d can stably bind to Topo II and HDAC.

Targeting the EGFR signaling pathway in cancer therapy: What's new in 2023?

INTRODUCTION

Epidermal growth factor receptor (EGFR) is frequently amplified, overexpressed, and mutated in multiple cancers. In normal cell physiology, EGFR signaling controls cellular differentiation, proliferation, growth, and survival. During tumorigenesis, mutations in EGFR lead to increased kinase activity supporting survival, uncontrolled proliferation, and migratory functions of cancer cells. Molecular agents targeting the EGFR pathway have been discovered, and their efficacy has been demonstrated in clinical trials. To date, 14 EGFR-targeted agents have been approved for cancer treatments.

AREAS COVERED

This review describes the newly identified pathways in EGFR signaling, the evolution of novel EGFR-acquired and innate resistance mechanisms, mutations, and adverse side effects of EGFR signaling inhibitors. Subsequently, the latest EGFR/panEGFR inhibitors in preclinical and clinical studies have been summarized. Finally, the consequences of combining immune checkpoint inhibitors and EGFR inhibitors have also been discussed.

EXPERT OPINION

As new mutations are threatened against EGFR-tyrosine kinase inhibitors (TKIs), we suggest the development of new compounds targeting specific mutations without inducing new mutations. We discuss potential future research on developing EGFR-TKIs specific for exact allosteric sites to overcome acquired resistance and reduce adverse events. The rising trend of EGFR inhibitors in the pharma market and their economic impact on real-world clinical practice are discussed.

Novel 2-Thiouracil-5-Sulfonamide Derivatives: Design, Synthesis, Molecular Docking, and Biological Evaluation as Antioxidants with 15-LOX Inhibition

New antioxidant agents are urgently required to combat oxidative stress, which is linked to the emergence of serious diseases. In an effort to discover potent antioxidant agents, a novel series of 2-thiouracil-5-sulfonamides (4-9) were designed and synthesized. In line with this approach, our target new compounds were prepared from methyl ketone derivative 3, which was used as a blocking unit for further synthesis of a novel series of chalcone derivatives 4a-d, thiosemicarbazone derivatives 5a-d, pyridine derivatives 6a-d and 7a-d, bromo acetyl derivative 8, and thiazole derivatives 9a-d. All compounds were evaluated as antioxidants against 2,2-diphenyl-1-picrylhydrazyl (DPPH), hydrogen peroxide (H₂O₂), lipid peroxidation, and 15-lipoxygenase (15-LOX) inhibition activity. Compounds 5c, 6d, 7d, 9b, 9c, and 9d demonstrated significant RSA in all three techniques in comparison with ascorbic acid and 15-LOX inhibitory effectiveness using quercetin as a standard. Molecular docking of compound 9b endorsed its proper binding at the active site pocket of the human 15-LOX which explains its potent antioxidant activity in comparison with standard ascorbic acid.

Proline-rich 11 (PRR11) promotes the progression of cutaneous squamous cell carcinoma by activating the EGFR signaling pathway

Cutaneous squamous cell carcinoma (cSCC) is one of the most common skin malignancies, and its incidence rate is increasing worldwide. Proline-rich 11 (PRR11) has been reported to be involved in the occurrence and development of various tumors. However, the role of PRR11 in cSCC remains unknown. In the present study, we observed upregulated expression of PRR11 in cSCC tissues and cell lines. Knockdown of PRR11 in the cSCC cell lines A431 and SCL-1 inhibited cell proliferation by inducing cell cycle arrest during the G1/S phase transition, promoted cell apoptosis, and reduced cell migration and invasion in vitro. Conversely, overexpression of PRR11 promoted cell proliferation, decreased cell apoptosis, and enhanced cell migration and invasion. PRR11 knockdown also inhibited cSCC tumor growth in a mouse xenograft model. Mechanistic investigations by RNA sequencing revealed that 891 genes were differentially expressed genes between cells with PRR11 knockdown and control cells. Enrichment analysis of different genes showed that the epidermal growth factor receptor (EGFR) signaling pathway was the top enriched pathway. We further validated that PRR11 induced EGFR pathway activity, which contributed to cSCC progression. These data suggest that PRR11 may serve as a novel therapeutic target in cSCC.

Novel thiazole derivatives incorporating phenyl sulphonyl moiety as potent BRAFV600E kinase inhibitors targeting melanoma

Novel thiazole derivatives possessing phenyl sulfonyl moiety were designed and synthesized as B-RAFV600E kinase inhibitors based on the clinically-approved anticancer drug, dabrafenib. All target compounds showed significant inhibition of B-RAFV600E kinase enzyme at nanomolar levels. Compounds 7b and 13a revealed excellent B-RAFV600E inhibitory activity, superior to that of dabrafenib with IC₅₀ values of 36.3 ± 1.9, 23.1 ± 1.2, and 47.2 ± 2.5 nM, respectively. Moreover, the title compounds were much more selective toward B-RAFV600E kinase than B-RAF wild type. In addition, the most potent compounds were further evaluated for their anticancer activity against B-RAFV600E-mutated and wild type melanoma cells. A positive correlation between the cytotoxic activity and selectivity for B-RAF V600E over B-RAF wild type was clearly observed for compounds 7b, 11c, 13a, and 17. All the screened compounds potently inhibited the growth of WM266.4 melanoma cells with IC₅₀ values in the range from 1.24 to 17.1 μM relative to dabrafenib (IC₅₀ = 16.5 ± 0.91 μM). Compounds 7b, 11a and 11c, 13a, and 17 were much more potent than dabrafenib against B-RAFV600E-mutated WM266.4 melanoma cells. Furthermore, compound 7b suppressed the phosphorylation of downstream ERK1/2 from WM266.4 cells. Also, the docking study revealed the proper orientation and well-fitting of the title compounds into the ATP binding site of B-RAFV600E kinase.

Thiazole derivatives 7b and 13a were superior to dabrafenib against B-RAFV600E kinase and potently inhibited the growth of WM266.4 melanoma cells. Compound 7b suppressed the phosphorylation of downstream ERK1/2 from WM266.4 cells.