Novel pyrazolo[3,4-d]pyrimidines: design, synthesis, anticancer activity, dual EGFR/ErbB2 receptor tyrosine kinases inhibitory activity, effects on cell cycle profile and caspase-3-mediated apoptosis

In vitro and in silico analysis of synthesized N-benzyl indole-derived hydrazones as potential anti-triple negative breast cancer agents

Triple-negative breast cancer (TNBC) is one of the most aggressive forms of breast cancer, and it is characterized by a high recurrence rate and the rapid development of drug resistance across various subtypes. Currently, there is no targeted therapy, which is specifically approved for the treatment of TNBC. In this study, we synthesized a series of N-benzyl indole-3-carboxaldehyde-based hydrazones and subjected them to in vitro anticancer studies on MCF-10A and MDA-MB-231 breast cancer (BC) cell lines. Our in vitro results suggested that all the compounds exhibited significant anti-TNBC activity, especially on MDA-MB-231 cells. Compound 5b showed excellent activity on MDA-MB-231 (IC50 = 17.2 ± 0.4 nM). Furthermore, molecular docking analysis revealed that this compound had a higher binding affinity towards the target EGFR (epidermal growth factor receptor) with a docking score of -10.523 kcal mol-1. The molecular dynamics simulation of complex 5b:3W2S showed stable binding over a period of 100 ns. A detailed multi-linear regression (MLR) QSAR denoted the importance of key molecular descriptors, such as com_accminus_2A, fringNlipo6A, and sp3Cplus_AbSA. These analyses indicate that the synthesized compounds deserve further studies for developing novel and more potent candidates against triple-negative breast cancer.

Design, synthesis and molecular dynamics simulations of thiazole-based hydrazones targeting MDA-MB-231 breast cancer cells

This study presents the design, synthesis of thiazole-based Hydrazones as potential inhibitors targeting in MDA-MB-231 triple-negative breast cancer cells. A series of quinazoline-thiazole and isatin-thiazole derivatives were synthesized and evaluated for their anti-proliferative activity. Compounds 12d and 12f (quinazoline-thiazole) demonstrated significant inhibitory effects, with IC50 values of 1.90 ± 1.69 μM and 2.55 ± 1.26 μM, outperforming toceranib (IC50: 2.28 ± 0.17 μM). Similarly, compounds 5m and 5l (isatin-thiazole) exhibited strong activity with IC50 values of 0.86 ± 1.19 μM and 0.73 ± 1.05 μM, respectively. To explore the compound induced cell apoptosis, flow cytometry analysis revealed compound 5l to be inducing apoptosis potential twice as compared to 12d compound. Additionally, the regulation of key cancer-related proteins, including EGFR, NFKB1, PIK3CB, and others, was predicted, shedding light on the molecular mechanisms underlying their anti-cancer activity and molecular docking studies revealed interactions with critical amino acids in the EGFR binding pocket, such as MET793, PHE795, and CYS775. These interactions were further supported by molecular dynamics simulations, which assessed the stability and conformational behavior of the compounds within the binding site. MM/GBSA and DFT calculations confirmed the stability and energy profiles of these hybrids. The study predicts the regulation of proteins involved in cancer pathways, suggesting that compounds 5m, 5l, 12d and 12f are promising candidates for EGFR-targeted therapies in breast cancer treatment.

Pyrimidine-based dual-target inhibitors targeting epidermal growth factor receptor for overcoming drug resistance in cancer therapy(2006-present)

The epidermal growth factor receptor (EGFR) is a pivotal member of the epidermal growth factor receptor family, exerting crucial regulatory influence on cellular physiological processes, particularly in relation to cell growth, proliferation, and differentiation. In recent years, numerous EGFR inhibitors have been introduced to the market; unfortunately, the effectiveness of single-target EGFR inhibitors has been compromised due to the development of drug resistance caused by EGFR mutations. Despite attempts by some researchers to address this issue through combination therapy with two or more drugs, instances of dose-limiting toxicities have been observed. Consequently, EGFR dual-target inhibitors have emerged as a burgeoning field in cancer treatment, offering a novel therapeutic option for solid tumors with the added benefits of reduced risk of resistance, lower dosage requirements, diminished toxicity profiles, and enhanced efficacy. At present, a series of EGFR dual-target inhibitors with diverse structures have been developed successively. In this study, we initially investigated the pyrimidine-based EGFR dual-target inhibitors that have been reported in the past two decades and categorized them into aminopyrimidine derivatives and heterocyclic pyrimidine derivatives with increased molecular complexity. Subsequently, we comprehensively summarized the biological activity and structure-activity relationship of this class of inhibitors in the context of cancer therapy, while also exploring potential opportunities and challenges associated with their application in this field. The present study provides a partial framework to guide future endeavors in drug development.

Pharmacophore-linked pyrazolo[3,4-d]pyrimidines as EGFR-TK inhibitors: Synthesis, anticancer evaluation, pharmacokinetics, and in silico mechanistic studies

Targeting the epidermal growth factor receptors (EGFRs) with small inhibitor molecules has been validated as a potential therapeutic strategy in cancer therapy. Pyrazolo[3,4-d]pyrimidine is a versatile scaffold that has been exploited for developing potential anticancer agents. On the basis of fragment-based drug discovery, considering the essential pharmacophoric features of potent EGFR tyrosine kinase (TK) inhibitors, herein, we report the design and synthesis of new hybrid molecules of the pyrazolo[3,4-d]pyrimidine scaffold linked with diverse pharmacophoric fragments with reported anticancer potential. These fragments include hydrazone, indoline-2-one, phthalimide, thiourea, oxadiazole, pyrazole, and dihydropyrazole. The synthesized molecules were evaluated for their anticancer activity against the human breast cancer cell line, MCF-7. The obtained results revealed comparable antitumor activity with that of the reference drugs doxorubicin and toceranib. Docking studies were performed along with EGFR-TK and ADMET profiling studies. The results of the docking studies showed the ability of the designed compounds to interact with key residues of the EGFR-TK through a number of covalent and noncovalent interactions. The obtained activity of compound 25 (IC50 = 2.89 µM) suggested that it may serve as a lead for further optimization and drug development.

Exploring the antiproliferative and proapoptotic activities of new pyridopyrimidine derivatives and their analogs

This study investigates a series of newly synthesized compounds, including pyridopyrimidine derivatives (9a-g), tricyclic pyridotriazolopyrimidine analogs (18a-d), and dihydropyrimidinones (22a-i), as apoptotic inducers and inhibitors of phosphatidylinositol-3-kinase α (PI3Kα), with potential anticancer activity. An initial in vitro screening of 60 cancer cell lines identified pyridopyrimidine derivatives 9a-g as promising broad-spectrum anticancer agents, with compound 9e demonstrating the strongest inhibitory activity, particularly against T-47D breast cancer cells. Notably, the antitumor potency of compound 9e surpassed that of Pictilisib, inducing G2-M phase cell cycle arrest and initiating apoptosis through the intrinsic apoptotic pathway. Molecular docking studies further indicated that compound 9e binds to PI3Kα in a similar fashion to the co-crystallized ligand. Moreover, compound 9e exhibited favorable drug-like properties, including compliance with Lipinski's rule and Veber's rule, good solubility, acceptable TPSA, and high gastrointestinal absorption reinforcing its potential as a highly effective anticancer agent.

Design, synthesis, in vitro, and in silico studies of novel isatin-hybrid hydrazones as potential triple-negative breast cancer agents

Recent advances in cancer therapy have been made possible by monoclonal antibodies, domain antibodies, antibody drug conjugates, etc. The most impact has come from controlling cell cycle checkpoints through checkpoint inhibitors. This manuscript explores the potential of a series of novel N-benzyl isatin based hydrazones (5-25), which were synthesized and evaluated as anti-breast cancer agents. The synthesized hydrazones of N-benzyl isatin were screened in vitro against two cell lines, the MDA-MB-231 breast cancer cell line and the MCF-10A breast epithelial cell line. The results indicated that all compounds showed great potential against the triple-negative MDA-MB-231 breast cancer cell line. Compound 23 with nitro substitution at the 4th position of the phenyl ring exhibited significant antiproliferative potential for the MDA-MB-231 with an IC50 value of 15.8 ± 0.6 μM. Molecular dynamics and molecular docking simulations were performed to get a deeper understanding of the interactions between the synthesized compounds and cancer cells.

Developing new anticancer agents: Design, synthesis, biological evaluation and in silico study of several functionalized pyrimidine-5-carbonitriles as small molecules modulators targeting breast cancer

Committed to our growing effort addressed toward the development of potent anti-breast cancer candidates, new 4-hydrazinylpyrimidine-5-carbonitriles featuring a morpholinyl or piperidinyl moiety at the position-2 and derivatized with various functionalities at the hydrazinyl group were designed through structure optimization, and their antiproliferative potency against two human breast cancer (BC) cell lines, relative to the reference drug 5-FU, was evaluated. Compounds showing remarkable cytotoxic activity versus the hormone dependent MCF-7 cell line (IC50 = 1.62 ± 0.06 µM- 9.88 ± 0.38 µM) and the non-hormone dependent MDA-MB-231 cell line (IC50 = 3.26 ± 0.14 µM-12.93 ± 0.55 µM) were further tested by multiple assays for clarification of their potential activity. Promising derivatives revealing low damage to healthy cells were subject to enzymatic inhibitory assessment against ARO and EGFR and their activities compared to letrozole and erlotinib respectively. Compounds 3c, 6a as well as compounds 4c, 4d proved to be good inhibitors of the ARO and EGFR enzymes respectively. Active compounds were also evaluated for their underlying mode of action by further investigation for CDK, Hsp90, PI3K inhibition and compared to normal MCF-10A cells and assessed for their enhancement of the caspase 9 levels. Additionally, cell cycle analysis and apoptotic induction were performed. They demonstrated remarkable activities in the previous assays and emanated as leads as anti-breast cancer candidates. Eventually, molecular docking analysis revealed that hit compounds 3c, 4c, 4d, and 6a could bind favorably to the proposed in silico models of various protein-ligand interactions. Therefore, our promising top candidates, by demonstrating appreciable anti-breast cancer activities, present valuable prospects for optimization, potency enhancement and future application.

Anticancer and Antibacterial Activeness of Fused Pyrimidines: Newfangled Updates

Pyrimidine-based heterocyclic compounds are garnering substantial interest due to their essential role as a class of natural and synthetic molecules. These compounds show a diverse array of biologically relevant activities, making them highly prospective candidates for clinical translation as therapeutic agents in combating various diseases. Pyrimidine derivatives and their fused analogues, such as thienopyrimidines, pyrazolopyrimidines, pyridopyrimidines, and pyrimidopyrimidines, hold immense possibility in both anticancer and antibacterial research. These compounds exhibit notable efficacy by targeting protein kinases, which are crucial enzymes regulating fundamental cellular processes like metabolism, migration, division, and growth. Through enzyme inhibition, these derivatives disrupt key cellular signaling pathways, thereby affecting critical cellular functions and viability. The advantage lies in the ubiquity of the pyrimidine structure across various natural compounds, enabling interactions with enzymes, genetic material, and cellular components pivotal for chemical and biological processes. This interaction plays a central role in modulating vital biological activities, making pyrimidine-containing compounds indispensable in drug discovery. In the realm of anticancer therapy, these compounds strategically target key proteins like EGFR, important for aberrant cell growth. Fused pyrimidine motifs, exemplified by various drugs, are designed to inhibit EGFR, thereby impeding tumor progression. Moreover, these compounds influence potent antibacterial activity, interfering with microbial growth through mechanisms ranging from DNA replication inhibition to other vital cellular functions. This dual activity, targeting both cancer cells and microbial pathogens, underscores the versatility and potential of pyrimidine derivatives in medical applications. This review provides insights into the structural characteristics, synthesis methods, and significant medicinal applications of fused pyrimidine derivatives, highlighting their double role in combating cancer and bacterial infections.

New S-substituted-3-phenyltetrahydrobenzo[4,5]thieno[2,3-d]pyrimidin-4(3H)-one scaffold with promising anticancer activity profile through the regulation and inhibition of mutated B-RAF signaling pathway

Novel 3-phenyltetrahydrobenzo[4,5]thieno[2,3-d]pyrimidine derivatives were synthesized and screened for their antiproliferative activity against a panel of 60 cancer cell lines. Derivatives 5b, 5f, and 9c showed significant antitumor activity at a single dose with mean growth inhibition of 55.62%, 55.79%, and 71.40%, respectively. These compounds were further investigated against HCT-116, colon cancer cell line, and FHC, normal colon cell line. Compound 9c showed the highest activity with IC50 = 0.904 ± 0.03 µM and SI = 20.42 excelling doxorubicin which scored IC50 = 2.556 ± 0.09 µM and SI = 6.19. Compound 9c was also the most potent against B-RAFWT and mutated B-RAFV600E with IC50 = 0.145 ± 0.005 and 0.042 ± 0.002 µM, respectively in comparison with vemurafenib with IC50 = 0.229 ± 0.008 and 0.038 ± 0.001 µM, respectively. The cell cycle analysis showed that 9c increased the cell population and induced an arrest in the cell cycle of HCT-116 cancer cells at the G0-G1 stage with 1.23-fold. Apoptosis evaluation showed that compound 9c displayed an 18.18-fold elevation in total apoptosis of HCT-116 cancer cells in comparison to the control. Compound 9c increased the content of caspase-3 by 3.52-fold versus the control. A molecular modeling study determined the binding profile and interaction of 9c with the B-RAF active site.

Design, synthesis, and biological evaluation of novel thiazole derivatives as PI3K/mTOR dual inhibitors

The development of anticancer drugs targeting both PI3K and mTOR pathways is recognized as a promising cancer therapeutic approach. In the current study, we designed and synthesized seventeen new thiazole compounds to investigate their effect on both PI3K and mTOR as well as their anti-apoptotic activity. All the synthesized thiazoles were investigated for their antiproliferative activity on a panel of 60 different cancer cell lines at the National Cancer Institute. Compounds 3b and 3e were selected for further investigation at five dose concentrations due to their effective growth inhibiting activity. Compounds 3b and 3e were further evaluated for their in vitro inhibitory activities against PI3Kα and mTOR compared to alpelisib and dactolisib, respectively as reference drugs. The inhibitory effect of compound 3b on PI3Kα was similar to alpelisib, but it showed weaker inhibitory activity on mTOR compared to dactolisib. Moreover, compound 3b exhibited significantly higher inhibitory activity compared to compound 3e against both PI3Kα and mTOR. The cell cycle analysis showed that compounds 3b and 3e induced G0-G1 phase cell cycle arrest in the leukemia HL-60(TB) cell line. Meanwhile, they significantly increased the total apoptotic activity which was supported by an increase in the level of caspase-3 in leukemia HL-60(TB) cell lines. Molecular docking experiments provided additional explanation for these results by demonstrating the ability of these derivatives to form a network of key interactions, known to be essential for PI3Kα/mTOR inhibitors. All these experimental results suggested that 3b and 3e are potential PI3Kα/mTOR dual inhibitors and could be considered promising lead compounds for the development of anticancer agents.

Crystal structure determination and analyses of Hirshfeld surface, crystal voids, inter-molecular inter-action energies and energy frameworks of 1-benzyl-4-(methyl-sulfan-yl)-3a,7a-di-hydro-1H-pyrazolo-[3,4-d]pyrimidine

The pyrazolo-pyrimidine moiety in the title mol-ecule, C13H12N4S, is planar with the methyl-sulfanyl substituent lying essentially in the same plane. The benzyl group is rotated well out of this plane by 73.64 (6)°, giving the mol-ecule an approximate L shape. In the crystal, C-H⋯π(ring) inter-actions and C-H⋯S hydrogen bonds form tubes extending along the a axis. Furthermore, there are π-π inter-actions between parallel phenyl rings with centroid-to-centroid distances of 3.8418 (12) Å. A Hirshfeld surface analysis of the crystal structure indicates that the most important contributions to the crystal packing are from H⋯H (47.0%), H⋯N/N⋯H (17.6%) and H⋯C/C⋯H (17.0%) inter-actions. The volume of the crystal voids and the percentage of free space were calculated to be 76.45 Å3 and 6.39%, showing that there is no large cavity in the crystal packing. Evaluation of the electrostatic, dispersion and total energy frameworks indicate that the cohesion of the crystal structure is dominated by the dispersion energy contributions.

Thiazolation of phenylthiosemicarbazone to access new thiazoles: anticancer activity and molecular docking

Aim: Novel thiazole hybrids were synthesized via thiazolation of 4-phenylthiosemicarbazone (4). Materials & methods: The anticancer activity against the NCI 60 cancer cell line panel. Results: Methyl 2-(2-((1-(naphthalen-2-yl)ethylidene)hydrazineylidene)-4-oxo-3-phenylthiazolidin-5-ylidene)acetate (6a) showed significant anticancer activity at 10 μM with a mean growth inhibition (GI) of 51.18%. It showed the highest cytotoxic activity against the ovarian cancer OVCAR-4 with an IC50 of 1.569 ± 0.06 μM. Compound 6a inhibited PI3Kα with IC50 = 0.225 ± 0.01 μM. Moreover, compound 6a revealed a decrease of Akt and mTOR phosphorylation in OVCAR-4 cells. In addition, antibacterial activity showed that compounds 11 and 12 were the most active against Staphylococcus aureus. Conclusion: Compound 6a is a promising molecule that could be a lead candidate for further studies.

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

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

Design, synthesis, and 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.

An assessment of EGFR and HER2 inhibitors with structure activity relationship of fused pyrimidine derivatives for breast cancer: a brief review

Epidermal growth factor receptor (EGFR) and its subtype human epidermal growth factor receptor 2 (HER2) gets activated when its endogenous ligand(s) bind to its ATP binding site of target receptors. In breast cancer (BC), EGFR and HER2 are two proteins are overexpressed which leads to overexpression of cells proliferation and decreases cell death/apoptosis. Pyrimidine is one of the most widely studied heterocyclic scaffolds for EGFR as well as HER2 inhibition. We gather some remarkable results for fused-pyrimidine derivatives on various cancerous cell lines (in-vitro) and animal (in-vivo) evaluation to highlight their potency. The heterocyclic (five, six-membered, etc.) moieties which are coupled with pyrimidine moiety are potent against EGFR and HER2 inhibitions. Hence structure-activity relationship (SAR) plays important role in study of heterocyclic moiety along pyrimidine and effects of substituents, groups for increase or decrease in the cancerous activity and toxicity. By thoughtful of fused pyrimidines SAR study, it facilitates in receiving excellent overview of the compounds by concerning of efficacy and potential summary for future EGFR inhibitors. Furthermore, we studied the in-silico interactions of synthesized compounds to evaluate binding affinity towards the key amino acids..Communicated by Ramaswamy H. Sarma.

Computational Design, Synthesis, and Bioevaluation of 2-(Pyrimidin-4-yl)oxazole-4-carboxamide Derivatives: Dual Inhibition of EGFRWT and EGFRT790M with ADMET Profiling

The ongoing research in cancer treatment underscores the significance of dual epidermal growth factor receptor (EGFR) kinase inhibitors targeting both mutant and wild-type variants. In this study, employing in silico fragment-based drug design (FBDD) and computational analysis, we have successfully developed a novel chemical series of 2-(pyrimidin-4-yl)oxazole-4-carboxamide (16a-j) derivatives designed as dual EGFR kinase inhibitors. A comparative in vitro anticancer profile of the newly synthesized compounds (16a-j) was tested against a panel of five human cancer cell lines like prostate cancer (PC3 & DU-145), lung cancer (A549), human liver cancer (HEPG2), and breast cancer (MDA-MB-468) by employing MTT method. In this experiment a well-known anticancer agent, Etoposide was used as positive control. Most of the derivatives demonstrated significant cytotoxicity, ranging from excellent to moderate levels. The IC50 values for the synthesized compounds observed between 0.10 ± 0.052 to 9.83 ± 5.96 µM, while the positive control exhibited a range of 1.97 ± 0.45 µM to 3.08 ± 0.135 µM. These results indicate that the synthesized compounds demonstrate higher cytotoxic potency in comparison to the reference compound. Furthermore, all these compounds underwent screening against normal Vero cell lines to assess their cytotoxicity. In each case, the observed cytotoxicity values (IC50) were higher than 22 µM, affirming the compounds selectivity for cancer cell lines. Among the compounds investigated, three compounds (16a, 16e, and 16i) exhibited notable cytotoxicity, while two compounds (16g and 16h) demonstrated exceptional cytotoxicity. The selectivity index of the tested compounds indicates a pronounced preference for targeting cancer cell lines over normal cells. Furthermore, all the compounds 16a-j underwent assessment for their EGFR kinase inhibitory activity against both EGFRWT and mutated EGFRT790M. The results unveiled the potential eligibility of this new series of compounds as effective EGFR inhibitors. Moreover, compound 16h underwent additional testing for cell cycle analysis, revealing its capability to arrest the cell cycle in the G2/M phase and induce apoptosis at the IC50 concentration.

Preliminary anticancer evaluation of new Pd(II) complexes bearing NNO donor ligands

In this study we presented a novel series of NNO tridentate ligands generating imino, amido and oxo donor pocket for Pd(II) coordination. All the compounds were meticulously characterized by elemental analysis and advanced spectroscopic techniques, including FTIR, proton and carbon NMR. The synthesized compounds underwent rigorous evaluation for their potential as anti-cancer agents, utilizing the aggressive breast cancer cell lines MDA-MB (ATCC) and MCF-7 as a crucial model for assessing growth inhibition in cancer cells. Remarkably, the MTT assay unveiled the robust anti-cancer activity for all palladium complexes against MDA-MB-231 and MCF-7 cells. Particularly, complex [Pd(L1)(CH3CN)] exhibited exceptional potency with an IC50 value of 25.50 ± 0.30 µM (MDA-MB-231) and 20.76 ± 0.30 µM (MCF-7), compared to respective 27.00 ± 0.80 µM and 24.10 ± 0.80 µM for cisplatin, underscoring its promising therapeutic potential. Furthermore, to elucidate the mechanistic basis for the anti-cancer effects, molecular docking studies on tyrosine kinases, an integral target in cancer research, were carried out. The outcome of these investigations further substantiated the remarkable anticancer properties inherent to these innovative compounds. This research offers a compelling perspective on the development of potent anti-cancer agents rooted in the synergy between ligands and Pd(II) complexes and presenting a promising avenue for future cancer therapy endeavors.

Pyrazolo - Pyrimidines as Targeted Anticancer Scaffolds - A Comprehensive Review

BACKGROUND

Globally, cancer is the leading cause of death, which causes 10 million deaths yearly. Clinically, several drugs are used in treatment but due to drug resistance and multidrug resistance, there occurs a failure in the cancer treatment.

OBJECTIVES

The present review article is a comprehensive review of pyrazole and pyrimidine hybrids as potential anticancer agents.

METHODS

The review comprises more than 60 research works done in this field. The efficiency of the reported pyrazolopyrimidine fused heterocyclic with their biological data and the influence of the structural aspects of the molecule have been discussed.

RESULTS

This review highlighted pyrazolo-pyrimidines as targeted anticancer agents with effect on multiple targets.

CONCLUSION

The review will be helpful for the researchers involved in targeted drugs for cancer therapy for designing new scaffolds with pyrazolo-pyrimidine moieties.

Novel pyrazolo[3,4-d]pyrimidine derivatives: design, synthesis, anticancer evaluation, VEGFR-2 inhibition, and antiangiogenic activity

A novel series of 12 pyrazolo[3,4-d]pyrimidine derivatives were created and evaluated in vitro for their antiproliferative activity against the NCI 60 human tumor cell line panel. Compounds 12a-d displayed significant antitumor activity against MDA-MB-468 and T-47D (breast cancer cell lines), especially compound 12b, which exhibited the highest anticancer activity against MDA-MB-468 and T-47D cell lines with IC50 values of 3.343 ± 0.13 and 4.792 ± 0.21 μM, respectively compared to staurosporine with IC50 values of 6.358 ± 0.24 and 4.849 ± 0.22 μM. The most potent cytotoxic derivatives 12a-d were studied for their VEGFR-2 inhibitory activity to explore the mechanism of action of these substances. Compound 12b had potent activity against VEGFR-2 with an IC50 value of 0.063 ± 0.003 μM, compared to sunitinib with IC50 = 0.035 ± 0.012 μM. Moreover, there was an excellent reduction in HUVEC migratory potential that resulted in a significant disruption of wound healing patterns by 23% after 72 h of treatment with compound 12b. Cell cycle and apoptosis investigations showed that compound 12b could stop the cell cycle at the S phase and significantly increase total apoptosis in the MDA-MB-468 cell line by 18.98-fold compared to the control. Moreover, compound 12b increased the caspase-3 level in the MDA-MB-468 cell line by 7.32-fold as compared to the control.

A novel class of pyrazole analogues as aurora kinase A inhibitor: design, synthesis, and anticancer evaluation

Pyrazole, as a small molecule, was discovered for higher cytotoxicity and affinity towards Aurora-A kinase. Based on these facts, a novel pyrazole substituted at the 4th position was designed, synthesized, and evaluated against MCF-7, MDA-MB-23, and Vero (non-cancerous kidney cell) cell lines. Compounds5hand5eexhibited greater cytotoxicity in the series against MCF-7 and MDA-MB-231, with GI50 values of 0.12 µM and 0.63 µM, respectively, as compared to Imatinib (GI50 values of 16.08 µM and 10.36 µM). All of the compounds displayed selective cytotoxicity against cancer cells but not on normal Vero cells, supporting the design strategy to be a selective anticancer agent. Furthermore, compounds 5h and 5e inhibited Aurora-A kinase with IC50 values of 0.78 µM (4.70-fold) and 1.12 µM (2.84-fold), respectively, as compared to alisertib (IC50 = 3.36 µM). In addition, compound 5h significantly arrested the cell cycle at G2/M (34.89 %, 5.56-fold) and the apoptotic phase (25.04 %, 11.81-fold) compared to the control. It also triggered an increase in early (7.43 %) and late (14.89 %) phase apoptosis compared to vehicle (0.235 and 0.36 %, respectively), causing 37.89-fold higher total apoptosis in the annexin-V assay. These data imply that Aurora-A kinase inhibition may be linked to apoptosis induction and cell cycle arrest. Furthermore, their higher docking score in the study confirmed evidence of Aurora-kinase suppression. It was observed that fluorine and imidazole increased the H-bond and lipophilic interactions with the binding residue. Also, the substitution of electron-rich and lipophilic groups increased hydrophobic interactions. Moreover, the three-atom linkage (CH2NHCH2) expanded compound 5h to fill the cavity. Based on current findings, it is concluded that compounds 5h and 5e with strong Aurora-A kinase suppression may be promising anticancer agents.

Novel fused imidazotriazines acting as promising top. II inhibitors and apoptotic inducers with greater selectivity against head and neck tumors: Design, synthesis, and biological assessments

Although the great effectiveness of doxorubicin (Dox) in the treatment of many types of tumors, it showed limited effectiveness against the head and neck squamous cell carcinoma (HNSCC) subtype which is attributed to its reported multiple drug resistance (MDR). In the current study, we considered the essential pharmacophoric features of Dox as an effective Top. II inhibitor and sought to develop a novel set of imidazo[1,2-a] [1,3,5]triazin-2-amines (2a-2p) as a suggested anticancer option that could intercalate the DNA base pairs. We evaluated the % inhibition of the newly synthesized compounds on thirteen cancer cell lines and the analysis of structure-activity relationships revealed that the human head and neck cancer cell line (HNO97) was the most sensitive to their growth inhibition effect. Then, the IC50 values were recorded against the most sensitive cancer cell lines (HNO97, MDA-MB-231, and HEPG2), and compared to the normal cell line OEC (human oral epithelial cells). Compounds 2f and 2g showed very strong activities against HNO97 with IC50 values of (4 ± 1 and 3 ± 1.5 μg/mL), respectively, compared to that of Dox (9 ± 1.6 μg/mL). Next, a quantitative determination of human DNA Top. II concentrations in the most sensitive cell line (HNO97) were recorded for the most active anticancer derivatives. Again, compound 2f showed a superior Top. II inhibition with 87.86% compared to that of Dox (86.44%), while compound 2g achieved an inhibition of 81.37% which was close to the effect of Dox. To further investigate their effects on cell cycle progression and apoptosis induction in HNO97 cells, both 2f and 2g were selected for analysis. Both candidates arrested cell cycle progression at both the S and G2-M phases, as well as increased the early and late apoptosis phase ratios. Besides, both 2f and 2g were subjected to protein expression analysis of apoptosis-related genes (p53, BAX, IL-6, and BCL2). Moreover, the antioxidant effect of 2f and 2g was evaluated by measuring GSH, MDA, and NO markers in HNO97 cells. Furthermore, molecular docking for the newly designed tricyclic derivatives against both the Top. II and DNA double helix was carried out.

Recent advances in nitrogen-containing heterocyclic compounds as receptor tyrosine kinase inhibitors for the treatment of cancer: Biological activity and structural activity relationship

Erratic cell proliferation is the initial symptom of cancer, which can eventually metastasize to other organs. Before cancer becomes metastatic, its spread is triggered by pro-angiogenic factors including vascular endothelial growth factor receptor (VEGFR), epidermal growth factor receptor (EGFR), Platelet-derived growth factor receptor (PDGFR), fibroblast growth factor receptor (FGFR) and Platelet Factor (PF4), all of which are part of receptor tyrosine kinase (RTK) family. Receptor tyrosine kinases (RTKs) are cell-surface proteins and aresignaling enzymes that transfer ATP-phosphate to tyrosine residue substrates. Important biological processes like proliferation, differentiation, motility, and cell-cycle regulation are all possessedby these proteins. Unusual RTK expression is typically associated with cell growth abnormalities, which is linked to tumor acquisition, angiogenesis, and cancer progression. In addition to the already available medications, numerous other heterocyclic are being studied for their potential action against a variety of cancers. In the fight against cancer, in particular, these heterocycles have been used for their dynamic core scaffold and their inherent adaptability. In this review article, we have compiled last five years research work including nitrogen containing heterocycles that have targeted RTK. Herein, the SAR and activity of various compounds containing diverse heterocyclic (pyrimidine, indole, pyridine, pyrazole, benzimidazole, and pyrrole) scaffolds are discussed, and they may prove useful in the future for designing new leads against RTKs. Our focus in this manuscript is to comprehensively review the latest research on the biological activity and structural activity relationship of nitrogen compounds as RTK inhibitors. We believe that this may be an important contribution to the field, as it can help guide future research efforts and facilitate the development of more effective cancer therapies.

Design, synthesis, anticancer evaluation, and in silico studies of some thieno[2,3-d]pyrimidine derivatives as EGFR inhibitors

New series of 20 thieno[2,3-d]pyrimidine derivatives have been synthesized. The National Cancer Institute evaluated all the newly synthesized compounds for their antiproliferative activity against a panel of 60 cancer cell lines. Compound 7b exhibited a remarkable antineoplastic activity at 10 µM dose and was therefore tested at five dose concentrations. The significant and broad-spectrum antineoplastic action of compound 7b was observed against 37 of the tested cancer cell lines with a dose that inhibits 50% of the growth compared to control values in the micromolar range of 1.95-9.6 µM. The dose which inhibits the growth completely in the cytostatic range of 3.99-100 µM was also observed. Compound 7b effectively inhibited epidermal growth factor receptor (EGFR) with 50% inhibition concentration value (IC50 ) = 0.096 ± 0.004 compared to erlotinib with IC50  = 0.037 ± 0.002. Moreover, compound 7b revealed a powerful downregulation effect on total EGFR concentration and its phosphorylation. In addition, compound 7b inhibited phosphatidylinositol 3-kinase, protein kinase B, and the mammalian target of rapamycin pathway phosphorylation. Furthermore, compound 7b raised total apoptosis by 21.93-fold in the ovarian cancer cell line (OVCAR-4) and caused an arrest in the cell cycle in the G1/S phase. It also raised the level of caspase-3 by 4.72-fold. Furthermore, to determine the binding manner of the most effective derivatives and validate their capacity to comply with the pharmacophoric properties necessary for EGFR inhibition, they were docked into the active site of the EGFR.

Design, synthesis and molecular docking study of new pyrimidine-based hydrazones with selective anti-proliferative activity against MCF-7 and MDA-MB-231 human breast cancer cell lines

Efforts were directed on the design, synthesis and evaluation of the anticancer activity of some pyrimidine-based hydrazones against two breast cancer cell lines, MCF-7 and MDA-MB-231. Preliminary screening results revealed that some candidates scrutinized for their antiproliferative activities exhibited IC50 values of 0.87 μM-12.91 μM in MCF-7 and 1.75 μM-9.46 μM in MDA-MB-231 cells, indicating almost equal activities on both cell lines and better growth inhibition activities than those of the positive control 5-fluorouracil (5-FU) which displayed IC50 values of 17.02 μM and 11.73 μM respectively. Selectivity of the significantly active compounds was estimated against MCF-10A normal breast cells when compounds 7c, 8b, 9a and 10b exhibited superior activity for cancerous cells than for normal cells when compound 10b presented the best selectivity Index (SI) with respect to both MCF-7 and MDA-MB-231 cancer cells in comparison to the reference drug 5-FU. Mechanisms of their actions were explored by inspecting activation of caspase-9, annexin V staining and cell cycle analysis. It was noticed that compounds 7c, 8b, 8c 9a-c and 10b produced an increase in caspase-9 levels in MCF-7 treated cells with 10b inducing the highest elevation (27.13 ± 0.54 ng/mL) attaining 8.26-fold when compared to control MCF-7 which was higher than that of staurosporine (19.011 ± 0.40 ng/mL). The same compounds boosted caspase-9 levels in MDA-MB-231 treated cells when an increase in caspase-9 concentration reaching 20.40 ± 0.46 ng/mL (4.11-fold increase) was observed for compound 9a. We also investigated the role of these compounds for their increasing apoptosis ability against the 2 cell lines. Compounds 7c, 8b and 10b tested on MCF-7 cells displayed pre-G1 apoptosis and arrested cell cycle in particular at the S and G1 phases. Further clarification of their effects was made by modulating their related activities as inhibitors of ARO and EGFR enzymes when 8c and 9b showed 52.4% and 58.9% inhibition activity relative to letrozole respectively and 9b and 10b showed 36% and 39% inhibition activity of erlotinib. Also, the inhibition activity was verified by docking into the chosen enzymes.

Design and synthesis of novel hexahydrobenzo[4,5]thieno[2,3-d]pyrimidine derivatives as potential anticancer agents with antiangiogenic activity via VEGFR-2 inhibition, and down-regulation of PI3K/AKT/mTOR signaling pathway

New thieno[2,3-d]pyrimidine derivatives were designed and synthesized. The National Cancer Institute (NCI) evaluated the synthesized novel compounds against a panel of 60 tumor cell lines for their antiproliferative activity. Compounds 6b, 6f, and 6g showed potent anticancer activity at 10 µM dose, with mean GI of 20.86%, 76.41%, and 31.49%, respectively. Compound 6f was selected for five-dose concentrations evaluation. Compound 6f scored a submicromolar range of GI50 values against 10 cancer cell lines, indicating broad-spectrum and potent antiproliferative activity. Compound 6f TGI values were recorded in the cytostatic range of 4.02-95.1 µM. In comparison to sorafenib, the tested compounds 6b, 6f, and 6g inhibited VEGFR-2 with IC50 values of 0.290 ± 0.032, 0.066 ± 0.004, and 0.16 ± 0.006 µM, correspondingly. Compound 6f significantly reduced the total VEGFR-2 expression and its phosphorylation. Additionally, 6f reduced the phosphorylation of PI3K, Akt, and mTOR pathway proteins. Moreover, the migratory potential of HUVECs was significantly reduced, after 72 h of treatment with compound 6f, resulting in disrupted wound healing patterns which verified the angiogenesis suppression properties of compound 6f. Compound 6f increased the total apoptosis percentage by 21.27-fold compared to sorafenib, which caused a 24.11-fold increase in the total apoptosis percentage. This apoptotic activity was accompanied by a 7.81-fold increase in the level of apoptotic caspase-3. Furthermore, the cell cycle analysis revealed that the target derivative 6f reduced cellular proliferation and induced an arrest in HCT-15 colon cancer cell cycle at the S phase. Molecular modeling was used to determine the binding profile and affinity of derivative 6f toward the VEGFR-2 active site.

Design, synthesis, anticancer, and antibacterial evaluation of some quinazolinone-based derivatives as DHFR inhibitors

Two series of quinazolinone derivatives were designed and synthesized as dihydrofolate reductase (DHFR) inhibitors. All compounds were evaluated for their antibacterial and antitumor activities. Antibacterial activity was evaluated against three strains of Gram-positive and Gram-negative bacteria. Compound 3d exhibited the highest inhibitory activity against Staphylococcus aureus DHFR (SaDHFR) with IC50 of 0.769 ± 0.04 μM compared to 0.255 ± 0.014 μM for trimethoprim. Compound 3e was also more potent than trimethoprim against Escherichia coli DHFR (EcDHFR) with IC50 of 0.158 ± 0.01 μM and 0.226 ± 0.014 μM, respectively. Compound 3e exhibited a promising antiproliferative effect against most of the tested cancer cells. It also showed potent activity against leukemia (CCRF-CEM, and RPMI-8226); lung NCI-H522, and CNS U251 with GI% of 65.2, 63.22, 73.28, and 97.22, respectively. The cytotoxic activity of compound 3e was almost half the activity of doxorubicin against CCRF-CEM cell line with IC50 of 1.569 ± 0.06 μM and 0.822 ± 0.03 µM, respectively. In addition, compound 3e inhibited human DHFR with IC50 value of 0.527 ± 0.028 µM in comparison to methotrexate (IC50  = 0.118 ± 0.006 µM). Compound 3e caused an arrest of the cell cycle mainly at the S phase and caused a rise in the overall apoptotic percentage from 2.03% to 48.51%. (23.89-fold). Treatment of CCRF-CEM cells with compound 3e produced a significant increase in the active caspase-3 level by 6.25-fold compared to untreated cells. Molecular modeling studies were performed to evaluate the binding pattern of the most active compounds in the bacterial and human DHFR.

GC-MS Profiling and Biomedical Applications of Essential Oil of Euphorbia larica Boiss.: A New Report

The present study explored Euphorbia larica essential oil (ELEO) constituents for the first time, obtained via hydro-distillation by means of Gas Chromatography-Mass Spectrometry (GC-MS) profiling. The essential oil was screened in vitro against breast cancer cells, normal cell lines, α-glucosidase, carbonic anhydrase-II (CA-II), free radical scavenging and in vivo analgesic and anti-inflammatory capabilities. The GC-MS screening revealed that the ELEO comprises sixty compounds (95.25%) with the dominant constituents being camphene (16.41%), thunbergol (15.33%), limonene (4.29%), eremophilene (3.77%), and β-eudesmol (3.51%). A promising antidiabetic capacity was noticed with an IC50 of 9.63 ± 0.22 μg/mL by the ELEO as equated to acarbose with an IC50 = 377.71 ± 1.34 μg/mL, while a 162.82 ± 1.24 μg/mL inhibition was observed against CA-II. Regarding breast cancer, the ELEO offered considerable cytotoxic capabilities against the triple-negative breast cancer (MDA-MB-231) cell lines, having an IC50 = 183.8 ± 1.6 μg/mL. Furthermore, the ELEO was also tested with the human breast epithelial (MCF-10A) cell line, and the findings also presumed that the ELEO did not produce any damage to the tested normal cell lines. The ELEO was effective against the Gram-positive bacteria and offered a 19.8 ± 0.02 mm zone of inhibition (ZOI) against B. atrophaeus. At the same time, the maximum resistance with 18.03 ± 0.01 mm ZOI against the fungal strain Aspergillus parasiticus was observed among the tested fungal strains. An appreciable free radical significance was observed via the DPPH assay with an IC50 = 133.53 ± 0.19 µg/mL as equated to the ABTS assay having an IC50 = 154.93 ± 0.17 µg/mL. The ELEO also offered a substantial analgesic capacity and produced 58.33% inhibition in comparison with aspirin, a 68.47% decrease in writhes, and an anti-inflammatory capability of 65.54% inhibition, as equated to the standard diclofenac sodium having 73.64% inhibition. Hence, it was concluded that the ELEO might be a natural source for the treatment of diabetes mellitus, breast cancer, analgesic, inflammatory, and antimicrobial-related diseases. Moreover, additional phytochemical and pharmacological studies are needed to isolate responsible chemical ingredients to formulate new drugs for the examined activities.

Benzoxazole-appended piperidine derivatives as novel anticancer candidates against breast cancer

Novel series of benzoxazole-appended piperidine derivatives were planned, synthesized and screened against two breast cancer cell lines. Considerable antiproliferative activity was observed for screened compounds (IC₅₀ = 33.32 ± 0.2 µM to 7.31 ± 0.43 µM and 1.66 ± 0.08 µM to 12.10 ± 0.57 µM) against MCF-7 and MDA-MB-231 cell lines respectively being more potent than doxorubicin (IC₅₀ = 8.20 ± 0.39 µM and 13.34 ± 0.63 µM respectively). Active compounds were submitted for enzyme inhibition assays when 4d and 7h demonstrated potent EGFR inhibition (0.08 ± 0.002 µM and 0.09 ± 0.002 µM respectively) compared to erlotinib (0.11 ± 0.003 µM). However, no one compound displayed effective ARO inhibition activity as tested compounds were less active than letrozole. Apoptosis inducing ability results implied that apoptosis was provoked by significant stimulation of caspase-9 protein levels (4.25-7.04-fold) upon treatment of MCF-7 cells with 4a, 7h, 9, 12e and 12f. Alternatively, MDA-MB-231 cells treated with 4d, 7a, 12b and 12c considerably increased caspase-9 levels (2.32-4.06-fold). Cell cycle arrest and annexin-V/Propidium iodide assays further confirmed apoptosis when tested compounds arrested cell cycle at various phases and demonstrated high annexin V binding affinity. Docking outcomes proved valuable binding affinities for compounds 4d and 7h to EGFR enzyme while compounds 4a and 12e, upon docking into the active site of ARO, failed to interact with heme, suggesting their inabilities to act as AIs. Therefore, these benzoxazoles can act as promising candidates exhibiting EGFR inhibition and apoptosis-promoting properties.

Pyrazolo[3,4-d]pyrimidine scaffold: A review on synthetic approaches and EGFR and VEGFR inhibitory activities

The pyrazolo[3,4-d]pyrimidine core has received a lot of interest from the medicinal chemistry community as a promising framework for drug design and discovery. It is an isostere of the adenine ring of adenosine triphosphate, which allows it to mimic kinase active site hinge region binding contacts. This scaffold has a wide pharmacological and biological value, one of which is as an anticancer agent. Many successful anticancer medicines have been designed and synthesized using pyrazolo[3,4-d]pyrimidine as a key pharmacophore. The main synthetic routes of pyrazolo[3,4-d]pyrimidines as well as their recent developments as promising anticancer agents acting as endothelial growth factor receptors and vascular endothelial growth factor receptor inhibitors, published in the time frame from 1999 to 2022, are summarized in this review to set the direction for the design and synthesis of novel pyrazolo[3,4-d]pyrimidine derivatives for clinical deployment in cancer treatment.

Design and synthesis of novel quinazolinone-based derivatives as EGFR inhibitors with antitumor activity

Nineteen new quinazolin-4(3H)-one derivatives 3a–g and 6a–l were designed and synthesised to inhibit EGFR. The antiproliferative activity of the synthesised compounds was tested in vitro against 60 different human cell lines. The most potent compound 6d displayed superior sub-micromolar antiproliferative activity towards NSC lung cancer cell line NCI-H460 with GI₅₀ = 0.789 µM. It also showed potent cytostatic activity against 40 different cancer cell lines (TGI range: 2.59–9.55 µM). Compound 6d potently inhibited EGFR with IC₅₀ = 0.069 ± 0.004 µM in comparison to erlotinib with IC₅₀ value of 0.045 ± 0.003 µM. Compound 6d showed 16.74-fold increase in total apoptosis and caused cell cycle arrest at G1/S phase in breast cancer HS 578T cell line. Moreover, the most potent derivatives were docked into the EGFR active site to determine their binding mode and confirm their ability to satisfy the pharmacophoric features required for EGFR inhibition.

Efficient Synthesis with Green Chemistry Approach of Novel Pharmacophores of Imidazole-Based Hybrids for Tumor Treatment: Mechanistic Insights from In Situ to In Silico

Simple Summary

Here, we report the eco-friendly synthesis and antitumor potential of the imidazole hybrids of pyrimidine. The results showed that all the compounds possess excellent inhibition of tumors, promoting enzymes hCA-IX and hCA-II. Furthermore, the selectivity index showed that compounds 7, 10, and 11 are selective inhibitors of hCA-IX, while compound 2 is a selective inhibitor of hCA-IX. More importantly, all the active inhibitors are toxic to the breast cancer cell line and non-cytotoxic for the normal breast cell line. These compounds would be a suitable choice to investigate in the in vivo models to check their efficacy against these particular targets. These newly identified human carbonic anhydrase inhibitors have potential to be considered as therapeutic leads for the treatment of CA-related diseases, especially for breast and lung tumors and glaucoma. Furthermore, lead optimization and preclinical and clinical investigations of these compounds are necessary to develop potential drug entities for the treatment of cancer.

Abstract

Imidazole-based pyrimidine hybrids are considered a remarkable class of compounds in pharmaceutical chemistry. Here, we report the anticancer bioactivities of eleven imidazole-based pyrimidine hybrids (1–11) that specifically target cytosolic carbonic anhydrase (CAs) isoenzymes, including human CA-II and human CA-IX (hCA-II, and hCA-IX). A highly eco-friendly aqueous approach was used for the formation of a carbon–carbon bond by reacting aromatic nitro group substitution of nitroimidazoles with carbon nucleophiles. The in vitro results indicate that this new class of compounds (1–11) includes significant inhibitors of hCA IX with IC₅₀ values in the range of 9.6 ± 0.2–32.2 ± 1.0 µM, while hCA II showed IC₅₀ values in range of 11.6 ± 0.2–31.1 ± 1.3 µM. Compound 2 (IC₅₀ = 12.3 ± 0.1 µM) showed selective inhibition for hCA-II while 7, 8, and 10 (IC₅₀ = 9.6–32.2 µM) were selective for hCA-IX. The mechanism of action was investigated through in vitro kinetics studies that revealed that compounds 7, 3, 11, 10, 4, and 9 for CA-IX and 1, 2, and 11 for CA-II are competitive inhibitors with dissociation constant (Ki) in the range of 7.32–17.02 µM. Furthermore, the in situ cytotoxicity of these compounds was investigated in the human breast cancer cell line MDA-MB-231 and compared with the normal human breast cell line, MCF-10A. Compound 5 showed excellent anticancer/cytotoxic activity in MDA-MB-231 with no toxicity to the normal breast cells. In addition, in silico molecular docking was employed to predict the binding mechanism of active compounds with their targets. This in silico observation aligned with our experimental results. Our findings signify that imidazole-based hybrids could be a useful choice to design anticancer agents for breast and lung tumors, or antiglaucoma compounds, by specific inhibition of carbonic anhydrases.

First Report on Comparative Essential Oil Profile of Stem and Leaves of Blepharispermum hirtum Oliver and Their Antidiabetic and Anticancer Effects

The current research was designed to explore the Blepharispermum hirtum Oliver (Asteraceae) stem and leaves essential oil (EO) composition extracted through hydro-distillation using gas chromatography-mass spectrometry (GC-MS) analysis for the first time. The EOs of the stem and leaves of B. hirtum were comparatively studied for the in vitro antidiabetic and anticancer potential using in vitro α-glucosidase and an MTT inhibition assay, respectively. In both of the tested samples, the same number of fifty-eight compounds were identified and contributed 93.88% and 89.07% of the total oil composition in the EOs of the stem and leaves of B. hirtum correspondingly. However, camphene was observed as a major compound (23.63%) in the stem EO, followed by β-selinene (5.33%) and β-elemene (4.66%) and laevo-β-pinene (4.38%). While in the EO of the leaves, the dominant compound was found to be 24-norursa-3,12-diene (9.08%), followed by β-eudesmol (7.81%), β-selinene (7.26%), thunbergol (5.84%), and caryophyllene oxide (5.62%). Significant antidiabetic potential was observed with an IC50 of 2.10 ± 0.57 µg/mL by the stem compared to the EO of the leaves of B. hirtum, having an IC50 of 4.30 ± 1.56 µg/mL when equated with acarbose (IC50 = 377.71 ± 1.34 µg/mL). Furthermore, the EOs offered considerable cytotoxic capabilities for MDA-MB-231. However, the EO of the leaves presented an IC50 = 88.4 ± 0.5 μg/mL compared to the EO of the stem of B. hirtum against the triple-negative breast cancer (MDA-MB-231) cell lines with an IC50 = 123.6 ± 0.8 μg/mL. However, the EOs were also treated with the human breast epithelial (MCF-10A) cell line, and from the results, it has been concluded that these oils did not produce much harm to the normal cell lines. Hence, the present research proved that the EOs of B. hirtum might be used to cure diabetes mellitus and human breast cancer. Moreover, further studies are considered to be necessary to isolate the responsible bioactive constituents to devise drugs for the observed activities.

Polyoxometalate-based nanocomposites for antitumor and antibacterial applications

Polyoxometalates (POMs), as emerging inorganic metal oxides, have been shown to have significant biological activity and great medicinal value. Nowadays, biologically active POM-based organic-inorganic hybrid materials have become the next generation of antibacterial and anticancer drugs because of their customizable molecular structures related to their highly enhanced antitumor activity and reduced toxicity to healthy cells. In this review, the current developed strategies with POM-based materials for the purpose of antibacterial and anticancer activities from different action principles inducing cell death and hyperpolarization, cell plasma membrane destruction, interference with bacterial respiratory chain and inhibiting bacterial growth are overviewed. Moreover, specific interactions between POM-based materials and biomolecules are highlighted for a better understanding of their antibacterial and anticancer mechanisms. POMs have great promise as next-generation antibacterial and anticancer drugs, and this review will provide a valuable systematic reference for the further development of POM-based nanomaterials.

Crystal structure determination, Hirshfeld surface, crystal void, inter-molecular inter-action energy analyses, as well as DFT and energy framework calculations of 2-(4-oxo-4,5-di-hydro-1H-pyra-zolo[3,4-d]pyrimidin-1-yl)acetic acid

In the title mol-ecule, C7H6N4O3, the bicyclic ring system is planar with the carb-oxy-methyl group inclined by 81.05 (5)° to this plane. In the crystal, corrugated layers parallel to (010) are generated by N-H⋯O, O-H⋯N and C-H⋯O hydrogen-bonding inter-actions. The layers are associated through C-H⋯π(ring) inter-actions. A Hirshfeld surface analysis indicates that the most important contributions to the crystal packing are from H⋯O/O⋯H (34.8%), H⋯N/N⋯H (19.3%) and H⋯H (18.1%) inter-actions. The volume of the crystal voids and the percentage of free space were calculated to be 176.30 Å3 and 10.94%, showing that there is no large cavity in the crystal packing. Computational methods revealed O-H⋯N, N-H⋯O and C-H⋯O hydrogen-bonding energies of 76.3, 55.2, 32.8 and 19.1 kJ mol-1, respectively. Evaluations of the electrostatic, dispersion and total energy frameworks indicate that the stabilization is dominated via dispersion energy contributions. Moreover, the optimized mol-ecular structure, using density functional theory (DFT) at the B3LYP/6-311G(d,p) level, was compared with the experimentally determined one. The HOMO-LUMO energy gap was determined and the mol-ecular electrostatic potential (MEP) surface was calculated at the B3LYP/6-31G level to predict sites for electrophilic and nucleophilic attacks.

Design, synthesis and mechanistic studies of novel imidazo[1,2-a]pyridines as anticancer agents

Herein, the design, synthesis and mechanistic study of five series of imidazo[1,2-a]pyridines 8a-d, 9a-f, 11a-c, 12a-d and 14a-d as anticancer agents were discussed. The cytotoxicity of imidazo[1,2-a]pyridine derivatives was screened against NCI 60 cancer cell lines. The cytotoxicity of compounds 8b, 8c, 9e and 9f was then evaluated against leukemia K-562 cancer cell line and normal lung fibroblasts (WI38). The hydrazone derivatives 8b and 8c exhibited significant cytotoxic activities against the leukemia K-562 cancer cell line with good safety margins (IC₅₀ = 2.91 µM, SI = 8.32 and IC₅₀ = 1.09 µM, SI = 10.54, respectively). In addition, compounds 8b, 8c, 9e and 9f were tested for their EGFR and COX-2 inhibitory activities. The hydrazone derivatives 8b and 8c were the most active EGFR inhibitors with IC₅₀ values of 0.123 and 0.072 µM, respectively. Compound 8c selectively inhibited COX-2 (IC₅₀ = 1.09 µM, SI = 13.78). Moreover, the potential of compound 8c to induce apoptosis in leukemia K-562 cell line was determined. Compound 8c showed a pre-G1 apoptosis and a growth arrest of leukemia K-562 cell line at G1 phase of cell cycle. Also, compound 8c was able to induce caspase-3 overexpression (6.98 folds), if compared to control. Finally, molecular docking studies and physicochemical properties calculation of compounds 8b, 8c, 9e and 9f were carried out to explain the biological data and to predict bioavailability of the most active compounds.

Emerging strategies to overcome resistance to third-generation EGFR inhibitors

Epidermal growth factor receptor (EGFR), the receptor for members of the epidermal growth factor family, regulates cell proliferation and signal transduction; moreover, EGFR is related to the inhibition of tumor cell proliferation, angiogenesis, invasion, metastasis, and apoptosis. Therefore, EGFR has become an important target for the treatment of cancer, including non-small cell lung cancer, head and neck cancer, breast cancer, glioma, cervical cancer, and bladder cancer. First- to third-generation EGFR inhibitors have shown considerable efficacy and have significantly improved disease prognosis. However, most patients develop drug resistance after treatment. The challenge of overcoming intrinsic and acquired resistance in primary and recurrent cancer mediated by EGFR mutations is thus driving the search for alternative strategies in the design of new therapeutic agents. In view of resistance to third-generation inhibitors, understanding the intricate mechanisms of resistance will offer insight for the development of more advanced targeted therapies. In this review, we discuss the molecular mechanisms of resistance to third-generation EGFR inhibitors and review recent strategies for overcoming resistance, new challenges, and future development directions.

A Review on Fused Pyrimidine Systems as EGFR Inhibitors and Their Structure–Activity Relationship

Epidermal growth factor receptor (EGFR) belongs to the family of tyrosine kinase that is activated when a specific ligand binds to it. The EGFR plays a vital role in the cellular proliferation process, differentiation, and apoptosis. In the case of cancer, EGFR undergoes uncontrolled auto-phosphorylation that results in increased cellular proliferation and decreased apoptosis, causing cancer promotion. From the literature, it shows that pyrimidine is one of the most commonly studied heterocycles for its antiproliferative activity against EGFR inhibition. The authors have collated some interesting results in the heterocycle-fused pyrimidines that have been studied using different cell lines (sensitive and mutational) and in animal models to determine their activity and potency. It is quite clear that the fused systems are highly effective in inhibiting EGFR activity in cancer cells. Therefore, the structure–activity relationship (SAR) comes into play in determining the nature of the heterocycle and the substituents that are responsible for the increased activity and toxicity. Understanding the SAR of heterocycle-fused pyrimidines will help in getting a better overview of the molecules concerning their activity and potency profile as future EGFR inhibitors.

Novel 2-(5-Aryl-4,5-Dihydropyrazol-1-yl)thiazol-4-One as EGFR Inhibitors: Synthesis, Biological Assessment and Molecular Docking Insights

Introduction

Epidermal growth factor receptor (EGFR) regulates several cell functions which include cell growth, survival, multiplication, differentiation, and apoptosis. Currently, EGFR kinase inhibitors are of increasing interest as promising targeted antitumor therapeutic agents.

Methods

Different thiazolyl-pyrazoline derivatives (7a-o) were synthesized and were first tested for anti-proliferative effect towards the A549 lung cancer cell line and the T-47D breast cancer cell line in MTT assay. Thereafter, thiazolyl-pyrazolines (7b, 7g, 7l, and 7m) were subsequently evaluated for their PK inhibition for EGFR. Moreover, representative promising derivatives (7g and 7m) in cytotoxic and PK inhibition assays were tested to investigate their impact on the apoptosis and cell cycle phases in T-47D cells in order to explore more insights into the antitumor actions of the target thiazolyl-pyrazolines. Furthermore, docking studies were accomplished to evaluate the patterns of binding of thiazolyl-pyrazolines 7b, 7g, 7l, and 7m in the EGFR active pocket (PDB ID: 1M17).

Results

Testing the thiazolyl pyrazoline compounds 7a-o on A549 and T-47D cell lines showed IC₅₀ arrays between 3.92 and 89.03 µM, and between 0.75 and 77.10 µM, respectively. Also, the tested thiazolyl-pyrazolines (7b, 7g, 7l, and 7m) demonstrated significant sub-micromolar EGFR inhibitory actions with IC₅₀ values 83, 262, 171 and 305 nM, respectively, in comparison to erlotinib (IC₅₀ =57 nM).

Discussion

Generally, it was observed that the tested thiazolyl pyrazolines showed more potent antiproliferative activity toward breast cancer cells T-47D than toward lung cancer cell lines A549. In particular, thiazolyl pyrazolines 7g and 7m showed the best activity against A549 cells (IC₅₀ = 3.92 and 6.53 µM) and T-47D cells (IC₅₀ = 0.88 and 0.75 µM). Compounds 7g and 7m provoked a sub-G1 phase arrest and cell apoptosis which are in agreement with the expected outcome of EGFR inhibition. Finally, the molecular docking of 7g and 7m in the active site of EGFR revealed a common binding pattern similar to that of erlotinib which involves the accommodation of the 1,3 thiazol-4-one ring and pyrazoline ring of target compounds in the binding region of erlotinib’s quinazoline ring and anilino moiety.

Azole-pyrimidine Hybrid Anticancer Agents: A Review of Molecular Structure, Structure Activity Relationship and Molecular Docking

Cancer has emerged as one of the leading causes of deaths globally partly due to the steady rise in anticancer drug resistance. Pyrimidine and pyrimidine-fused heterocycles are some of the privileged scaffolds in medicine, as they possess diverse biological properties. Pyrimidines containing azole nucleus possesses inestimable anticancer potency and has enormous potential to conduct the regulation of cellular pathways for selective anticancer activity. The present review outlines the molecular structure of pyrimidine-fused azoles with significant anticancer activity. The structure activity relationship and molecular docking studies have also been discussed. The current review is the first complete compilation of significant literature on the proposed topic from 2016 to 2020. The information contained in this review offers a useful insight to chemists in the design of new and potent anticancer azole-pyrimidine analogues.

The long non-coding RNA UPAT promotes gastric cancer cell progression via UHRF1

BACKGROUND

LncRNA ubiquitin-like with PHD and RING finger domains 1 (UHRF1) protein associated transcript (UPAT) regulates the progression of many cancers. However, its role in gastric cancer (GC) is less frequently reported.

OBJECTIVE

In the context of the promoting effect of lncRNA on modulating GC progression, detailed insights into the role and underlying mechanism of UPAT in GC are the foothold in this study.

METHODS

Overall survival was calculated. The mRNA expressions of UPAT and UHRF1 were measured by qRT-PCR, and the protein expressions of UHRF1, Cyclin D1 and cleaved caspase-3 were determined by western blot. Cell viability, growth, migration and invasion were assessed by CCK-8, colony formation, wound healing and Transwell assays, respectively. Apoptosis rate and cell cycle were assayed by flow cytometry.

RESULTS

UPAT was overexpressed in GC tissue and cell lines. Decreased UPAT level was associated with higher overall survival. Down-regulation of UPAT diminished cell proliferation, Cyclin D1 expression, and migration and invasion rates, increased apoptosis rate and cleaved caspase-3 expression, and blocked cell cycle in AGS and NCI-N87 cells. UPAT expression in GC was positively correlated with UHRF1 expression. UHRF1 overexpression offset the inhibitory effects of UPAT down-regulation on cell proliferation, migration, invasion and cell cycle, and partially reversed the positive effect of UPAT down-regulation on apoptosis.

CONCLUSION

UPAT might positively regulate the progression of GC via interacting with UHRF1. The UHRF1/UPAT axis revealed in the present study may provide a promising approach to intervene in the progression of GC.

Pyrimidine-fused Dinitrogenous Penta-heterocycles as a Privileged Scaffold for Anti-Cancer Drug Discovery

Pyrimidine-fused derivatives that are the inextricable part of DNA and RNA play a key role in the normal life cycle of cells. Pyrimidine-fused dinitrogenous penta-heterocycles including pyrazolopyrimidines and imidazopyrimidines is a special class of pyrimidine-fused compounds contributing to an important portion in anti-cancer drug discovery, which have been discovered as core structure for promising anti-cancer agents used in clinic or clinical evaluations. Pyrimidine-fused dinitrogenous penta-heterocycles have become one privileged scaffold for anti-cancer drug discovery. This review consists of the recent progress of pyrimidine-fused dinitrogenous penta-heterocycles as anti-cancer agents and their synthetic strategies. In addition, this review also summarizes some key structure-activity relationships (SARs) of pyrimidine-fused dinitrogenous penta-heterocycle derivatives as anti-cancer agents.

Dual target inhibitors based on EGFR: Promising anticancer agents for the treatment of cancers (2017-)

The EGFR family play a significant role in cell signal transduction and their overexpression is implicated in the pathogenesis of numerous human solid cancers. Inhibition of the EGFR-mediated signaling pathways by EGFR inhibitors is a widely used strategy for the treatment of cancers. In most cases, the EGFR inhibitors used in clinic were only effective when the cancer cells harbored specific activating EGFR mutations which appeared to preserve the ligand-dependency of receptor activation but altered the pattern of downstream signaling pathways. Moreover, cancer is a kind of multifactorial disease, and therefore manipulating a single target may result in treatment failure. Although drug combinations for the treatment of cancers proved to be successful, the use of two or more drugs concurrently still was a challenge in clinical therapy owing to various dose-limiting toxicities and drug-drug interactions caused by pharmacokinetic profiles changed. Therefore, a single drug targeting two or multiple targets could serve as an effective strategy for the treatment of cancers. In recent, drugs with diverse pharmacological effects have been shown to be more advantageous than combination therapies due to their lower incidences of side effects and more resilient therapies. Accordingly, dual target-single-agent strategy has become a popular field for cancer treatment, and researchers became more and more interest in the development of novel dual-target drugs in recent years. In this review, we briefly introduce the EGFR family proteins and synergisms between EGFR and other anticancer targets, and summarizes the development of potential dual target inhibitors based on wild-type and/or mutant EGFR for the treatment of solid cancers in the past five years. Additionally, the rational design and SARs of these dual target agents are also presented in detailed, which will lay a significant foundation for the further development of novel EGFR-based dual inhibitors with excellent druggability.

Study on the effects of the different polar group of EPA-enriched phospholipids on the proliferation and apoptosis in 95D cells

EPA-enriched phosphatidylcholine (EPA-PC) and EPA-enriched phosphatidylethanolamine (EPA-PE) are newly identified marine phospholipids. The polar group of phospholipids is known to influence EPA-phospholipid activity. However, the differences in anti-tumor effects between EPA-PC and EPA-PE have not been reported. In this study, we evaluated the effects of two forms of EPA on the proliferation and apoptosis in the lung-cancer cell line 95D as well as possible molecular mechanisms. Our results showed that EPA-PC effectively inhibited proliferative activity and promoted apoptosis of 95D cells in a dose-dependent manner, while EPA-PE had no effect on cell proliferation, although it slightly promoted apoptosis. Western blot results showed that EPA-PC and EPA-PE upregulated the expression of PPARγ, RXRα, and PTEN, and downregulated the PI3K/AKT signaling pathway. Furthermore, EPA-PC and EPA-PE induced the expression of the pro-apoptotic gene, Bax, and reduced the expression of the anti-apoptotic gene, Bcl-xl. Additionally, EPA-PC and EPA-PE promoted the release of cytochrome c and activated the apoptotic enzyme-cleaved caspase-3. These data suggest that the anti-tumor effect of EPA-phospholipids may be exerted via a PPARγ-related mechanism. EPA-PC was more efficacious as compared to EPA-PE, which might be due to the different polar groups of phospholipids.

Synthesis, in vitro anticancer activity and in silico studies of certain isoxazole-based carboxamides, ureates, and hydrazones as potential inhibitors of VEGFR2

The ensuing research presents the results of in vitro anticancer activity of novel 28 compounds of isoxazole-based carboxamides 3(a-d); ureates 4(a-g), 5, 6, 7a,b, 8; and hydrazones 9(a-f), 10(a-d), 11a,b as potential inhibitors of VEGFR2. The carboxamides and ureates were synthesized by converting 5-(aryl)-isoxzaole-3-carbohydrazides 1a,b to the corresponding carbonylazides 2a,b followed by treatment with the appropriate amines. The hydrazones were directly obtained through condensation of the carbohydrazide 1a,b with aldehydes and/or ketones. The structures of the target compounds were confirmed by elemental and spectral analyses. A preliminary in vitro anticancer screening of solutions (10^-5M) on 60 cancer cell lines (NCI, USA) revealed that the carboxamide 3c is the most promising growth inhibitor. Explicitly, 3c showed potent anticancer activity at 10µ M against leukemia (HL-60(TB), K-562 and MOLT-4), colon cancer (KM12) and melanoma (LOX IMVI) cell lines with %GI range = 70.79-92.21. Evaluation of growth inhibitory activity of the synthesized compounds against hepatocellular carcinoma (HepG2), that overexpresses VEGFR2, showed superior activity of compounds 8, 10a and 10c with IC₅₀ in sub micromolar concentrations of 0.84, 0.79 and 0.69 μM, respectively, which is better than that of the reference drug, Sorafenib (IC₅₀ = 3.99 µM). Moreover, these compounds displayed high selective cytotoxicity for HepG2 cancer cells over the nontumorigenic THLE2 liver cells (SI range = 26.37-38.60) which reflect their safety. The results of VEGFR2 kinase inhibition assay demonstrate that, compounds 8 and 10a are the most active inhibitors with IC₅₀ = 25.7 and 28.2 nM, respectively, (Sorafenib IC₅₀ = 28.1 nM). Molecular docking of the synthesized derivatives to VEGFR2 (PDB: 3WZE) showed similar binding modes to that of the co-crystallized ligand, sorafenib. Moreover, the results of computational assessment of ADME and drug-likeness characteristics inspire further investigations of the new isoxazole-based derivatives to afford more potent, safe and orally active VEGFR2 inhibitors as potential anticancer drug candidates.

New thieno[3,2-d]pyrimidine-based derivatives: Design, synthesis and biological evaluation as antiproliferative agents, EGFR and ARO inhibitors inducing apoptosis in breast cancer cells

An array of newly synthesized thieno[3,2-d]pyrimidine-based derivatives and thienotriazolopyrimidines hybridized with some pharmacophoric anticancer fragments were designed, synthesized and assessed for their in vitro antiproliferative activity against MCF-7 and MDA-MB-231 breast cancer cell lines using erlotinib and pictilisib as reference standards in the MTT assay. In general, many compounds were endowed with considerable antiproliferative activity (IC₅₀ = 0.43-1.31 µM). Some of the tested compounds, namely 3c, 5b, 5c, 9d, 10, 11b and 13 displayed remarkable antiproliferative activity against both cell lines. Meanwhile, compounds 2c-e, 3b, 4a, 5a, 9c and 15b showed noticeable selectivity against MCF-7 cells while compounds 2b, 3a, 4b, 6a-c, 7, 8, 9b and 12 exhibited considerable selectivity against MDA-MB-231 cells. Further mechanistic evidences for their anticancer activities were provided by screening the most potent compounds against MCF-7 and/or MDA-MB-231 cells for EGFR and ARO inhibitory activities using erlotinib and letrozole as reference standards respectively. Results proved that, in general, tested compounds were better EGFRIs than ARIs. In addition, significant overexpression in caspase-9 level in treated MCF-7 breast cell line samples was observed for all tested compounds with the 4-fluorophenylhydrazone derivative 2d exhibiting the highest activation. In treated MDA-MB-231 breast cell line samples, 11b was found to highly induce caspase-9 level thereby inducing apoptosis. Cell cycle analysis and Annexin V-FITC/PI assay were also assessed for active compounds where results indicated that all tested compounds induced preG1 apoptosis and cell cycle arrest at G2/M phase. Compound 9d, as an inhibitor of ARO, was observed to downregulate the downstream signaling proteins HSP27 and p-ERK in MCF-7 cells. Furthermore, compound 11b downregulated EGFR expression as well as the downstream signaling protein p-AKT. Docking experiments on EGFR and ARO enzymes supported their in vitro results. Thus, the thienotriazolopyrimidines 11b and 12 showing good EGFR inhibition and the thieno[3,2-d]-pyrimidine derivatives 3b and 9d, eliciting the best ARO inhibition activity, can be considered as new candidates as anti-breast cancer agents that necessitate further development.

Thio-substituted derivatives of 4-amino-pyrazolo[3,4-d]pyrimidine-6-thiol as antiproliferative agents

The current study was designed to identify new compounds as potential antiproliferative drug candidates. Synthesis of heteroaromatic bicyclic and monocyclic derivatives as purine bioisosters was employed. Their antiproliferative activity was studied against U937 cancer cells. The most effective compounds were evaluated for their selectivity against cancer cells, the possible mechanism of cell death, and their interference with DNA replication. Among the synthesized compounds, only three (4b, 4j and 4l) demonstrated a value of IC₅₀ less than 20 μM. However, two of them (4b and 4l) were specific against cancer cells, with 4l presenting high selectivity. The presence of substituted pyrazolo[3,4-d]pyrimidine core is as essential for this activity as the presence of substituents at the thiol function in 6-position.