Structure optimization, synthesis, and biological evaluation of 6-(2-amino-1H-benzo[d]imidazole-6-yl)-quinazolin-4(3H)-one derivatives as potential multi-targeted anticancer agents via Aurora A/ PI3K/BRD4 inhibition

A new specific GluN2B partial antagonist ameliorates brain injury caused by ischemic stroke in rats

Ischemic stroke is one of the top-ranked causes of death and disability in the world, but still lacking efficacy treatment options. Excitotoxicity caused by NMDA receptors (NMDARs) hyperactivation plays a key role in brain injury after ischemic stroke. GluN2B, the regulatory subunit of NMDARs, plays an important role in brain injury induced by ischemic stroke, and specific antagonists of GluN2B can ameliorate brain damage induced by ischemic stroke in rats. However, over half a century after Memantine (the first NMDA partial inhibitor for Alzheimer's clinical treatment) was identified, only a few additional NMDA partial inhibitors, especially those specifically targeting GluN2B, have been discovered. In this study, by using whole patch-clamp technique and multiple molecular biological methods, we discovered a new specific GluN2B partial antagonist, named FLY26, and further determined its effects on alleviating the brain injury caused by ischemic stroke in rats. Our experiment results showed FLY26 suppressed the excitotoxicity caused by overactivation of NMDARs in SH-SY5Y cells, and ameliorated brain damage of middle cerebral artery occlusion (MACO) rats, within the dosage range of 1.5-6.0 mg/kg, via BDNF/TrkB signaling pathway. Our results indicated that FLY26 is a promising lead compound for the development of novel, specific GluN2B partial antagonist. Our results indicated that FLY26 is a promising lead compound for the development of novel, specific GluN2B partial antagonist, which may offer better safety profile as a therapeutic intervention for ischemic stroke.

Structure-based design of new anticancer N3-Substituted quinazolin-4-ones as type I ATP-competitive inhibitors targeting the deep hydrophobic pocket of EGFR

Epidermal growth factor receptor (EGFR) is amongst the earliest targeted kinases by small-molecule inhibitors for the management of EGFR-positive cancer types. While a few inhibitors are granted FDA approval for clinical use, discovery of new inhibitors is still of merit to enhance ligand-binding stability and subsequent enzyme inhibition. Thus, a structure-based design approach was adopted to devise a new series of twenty-nine N3-substituted quinazolin-4-ones as type I ATP-competitive inhibitors targeting the deep hydrophobic pocket of EGFR. The most active compounds demonstrated potent IC50s against MDA-MB-231 and HepG2 cancer cells being comparable to or better than the reference drugs erlotinib and lapatinib. IC50s of 5f and 15a against MDA-MB-231 were 3.34 and 4.99, whilst those against HepG2 were 6.37 and 2.18 μM, respectively. Also, members of this series demonstrated selective cytotoxicity against cancer cell lines showing low toxicity on human skin fibroblast normal cells hFB-4. Both 5f and 15a also effectively inhibited EGFR with sub-micromolar respective IC50s of 0.07 and 0.12 μM. The two derivatives halted the cell cycle progression of treated cancer cells and induced apoptosis as affirmed by flow cytometry along with RT-PCR-determined overexpression of the pro-apoptotic genes p53, Caspase 3, and Bax. Notably, docking and molecular dynamics simulations of members of this series of quinazolin-4-one derivatives showed that analogs with a short linker at the N3 position of the quinazoline ring exemplified by 5f bind to the active form of EGFR with their terminal aryl ring dwelling in the BPI pocket similar to erlotinib, while those with a longer linker represented by 15a bind to the inactive form in a comparable manner to lapatinib lodging the terminal phenyl in the BPII pocket.

Synthesis and Antitumor Activity of 6-(2-Aminobenzo[d]thiazol-5-yl) quinazolin-4(3H)-one Derivatives

Quinazolinones are key scaffolds in anticancer drug development. We previously identified the lead compound 16h from a series of 6-(1H-benzo[d]imidazol-6-yl) quinazolin-4(3H)-one derivatives. In this study, we optimized 16h to develop new 6-(2-aminobenzo[d]thiazol-5-yl) quinazolin-4(3H)-one derivatives, with compound 45 showing the best antiproliferative activity against A549 lung cancer cells (IC50: 0.44 μM) and good selectivity. Mechanistic studies revealed that compound 45 induced G1-phase arrest, inhibited ALK/PI3K/AKT signaling, disrupted mitochondrial membrane potential, and promoted apoptosis. It also significantly inhibited spheroid formation in a 3D cell culture model. In summary, the results suggest that compound 45 might have potential for the development of anticancer drugs.

Anticancer benzimidazole derivatives as inhibitors of epigenetic targets: a review article

Cancer is one of the leading causes of morbidity and mortality worldwide. One of the primary causes of cancer development and progression is epigenetic dysregulation, which is a heritable modification that alters gene expression without changing the DNA sequence. Therefore, targeting these epigenetic changes has emerged as a promising therapeutic strategy. Benzimidazole derivatives have gained attention for their potent epigenetic modulatory effects as they interact with various epigenetic targets, including DNA methyltransferases, histone deacetylases and histone methyltransferases. This review provides a comprehensive overview of benzimidazole derivatives that inhibit different acetylation and methylation reader, writer and eraser epigenetic targets. Herein, we emphasize the therapeutic potential of these compounds in developing targeted, less toxic cancer therapies. Presently, some promising benzimidazole derivatives have entered clinical trials and shown great advancements in the fields of hematological and solid malignancy therapies. Accordingly, we highlight the recent advancements in benzimidazole research as epigenetic agents that could pave the way for designing new multi-target drugs to overcome resistance and improve clinical outcomes for cancer patients. This review can help researchers in designing new anticancer benzimidazole derivatives with better properties.

Current developments in PI3K-based anticancer agents: Designing strategies, biological activity, selectivity, structure-activity correlation, and docking insight

The phospatidylinositol-3 kinase (PI3K) pathway is a critical intracellular signalling mechanism that is changed or amplified in a variety of cancers, including breast, gastric, ovarian, colorectal, prostate, glioma, and endometrial. PI3K signalling is important for cancer cell survival, angiogenesis, and metastasis, making it a promising therapeutic target. The PI3K kinases in their different isoforms, namely α, β, δ, and γ, encode PIK3CA, PIK3CB, PIK3CD, and PIK3CG genes. Specific gene mutation or overexpression of the protein is responsible for the therapeutic failure of current therapeutics. There are several current and completed clinical trials using PI3K inhibitors (pan, isoform-specific, and dual PI3K/mTOR) to develop effective PI3K inhibitors capable of overcoming resistance to existing drugs. However, the bulk of these inhibitors have had their indications revoked or voluntarily withdrawn due to concerns about their harmful consequences. Several inhibitors containing medicinally privileged scaffolds like thiazole, triazine, benzimidazole, podophyllotoxin, pyridine, quinazoline, thieno-triazole, pyrimidine, triazole, benzofuran, imidazo-pyridazine, oxazole, coumarin, and azepine derivatives have been explored to target the PI3K pathway and/or a specific isoform in the current overview. This article reviews the structure, biological activities, and clinical status of PI3K inhibitors. It focuses on the development techniques, docking insight, and structure-activity connections of PI3K-based inhibitors. The findings provide useful insights and future approaches for the development of promising PI3K-based inhibitors.

Recent advancements in mechanistic research, therapeutic potential, and structure-activity relationships of aurora kinase inhibitors in cancer therapies

Aurora kinases (AURKs)-a family of serine/threonine protein kinases consisting of AURK-A, AURK-B, and AURK-C, are critical regulators of chromosomal segregation, centrosome maturation, and cytokinesis during the cell cycle. Each kinase is activated via phosphorylation at unique threonine residues: Thr288 (AURK-A), Thr232 (AURK-B), and Thr195 (AURK-C). Activation of AURK-A and AURK-B through phosphorylation triggers a series of downstream signaling pathways, including RalA, NF-κB, p53, PLK1, BRCA1/BRCA2, H2AX, and Kif2C, as well as multiple transmembrane kinase receptors. Dysregulation of these pathways has been implicated in cancer development and progression, positioning AURKs as pivotal targets for anticancer drug research. Inhibition of AURKs has demonstrated significant efficacy in tumor growth suppression and induction of cancer cell death, thereby focusing recent research on the development of potent AURK inhibitors. This review provides an in-depth exploration of AURK inhibitors, discussing their biological activities, structure-activity relationships, selectivity profiles, and mechanisms of action. Notably, compounds 6, 27, and 16 exhibit potent AURK-A inhibition with IC50 values of 1.7 nM, 11.83 nM, and 15 nM, respectively. Similarly, compounds 28, 16, and 7 demonstrate strong AURK-B inhibitory activity, with IC50 values of 10.5 nM, 12 nM, and 14.09 nM, respectively. This comprehensive overview aims to support medicinal chemists in developing more potent, selective, and safe AURK inhibitors as potential anticancer therapeutics.

Discovery of 3-(2-aminobenzo[d]thiazol-5-yl) benzamide derivatives as potent anticancer agents via ROR1 inhibition

Receptor tyrosine kinase-like orphan receptor 1 (ROR1) is a member of the receptor tyrosine kinase family, which was overexpressed in non-small cell lung cancer (NSCLC) and essential for cell proliferation, migration and invasion. Recently, accumulating evidences indicated that ROR1 played a critical role in maintaining the balance between the Src survival pathway and the p38 apoptotic pathway. Hence, ROR1 was considered as an attractive therapeutic target for the development of anticancer drugs. However, only a few small molecule ROR1 inhibitors were reported until now. Herein, a series of 3-(2-aminobenzo[d]thiazol-5-yl) benzamide derivatives were designed and synthesized via bioisosterism and simplification strategy guided by the lead compound 9a. MTT assay showed that compound 7h exhibited the best anti-cancer properties with IC50 values of 18.16, 8.11 and 3.5 μM against A549, PC9 and H1975 cells, respectively. Meanwhile, the selectivity index (SI) of compound 7h for H1975 cells was 22.86 compared to that of the lead compound 9a of 1.83, which is at least 12 fold higher than that of lead compound 9a, suggesting that 7h had a favorable safety profile. In addition, the molecular docking, CETSA and DARTS assays suggested that compound 7h might be a novel small molecule ROR1 inhibitor. More importantly, compound 7h significantly suppressed the migration and invasion of H1975 cells in vitro by blocking Src survival pathway and reactivating the p38 apoptotic pathway, and induced H1975 cell cycle arrest in G1 phase. Collectively, our work suggested that the ROR1 inhibitor 7h might be a novel drug candidate for NSCLC treatment.

Research progress on the relationship between AURKA and tumorigenesis: the neglected nuclear function of AURKA

AURKA is a threonine or serine kinase that needs to be activated by TPX2, Bora and other factors. AURKA is located on chromosome 20 and is amplified or overexpressed in many human cancers, such as breast cancer. AURKA regulates some basic cellular processes, and this regulation is realized via the phosphorylation of downstream substrates. AURKA can function in either the cytoplasm or the nucleus. It can promote the transcription and expression of oncogenes together with other transcription factors in the nucleus, including FoxM1, C-Myc, and NF-κB. In addition, it also sustains carcinogenic signaling, such as N-Myc and Wnt signaling. This article will focus on the role of AURKA in the nucleus and its carcinogenic characteristics that are independent of its kinase activity to provide a theoretical explanation for mechanisms of resistance to kinase inhibitors and a reference for future research on targeted inhibitors.

Synthesis and antitumor activities of novel 3-(6-aminopyridin-3-yl)benzamide derivatives: Inducing cell cycle arrest and apoptosis via AURKB transcription inhibition

Here, a series of 3-(6-aminopyridin-3-yl) benzamide derivatives were designed and synthesized. Cell viability assay indicated that most compounds exhibited potent antiproliferative activity against all the tested cancer cells. Among them, compound 7l displayed the best antiproliferative activity particularly in A549 cells, with an IC50 value of 0.04 ± 0.01 μM. RNA-seq analysis was employed to explore the potential pathways related to the antiproliferative activity of compound 7l. The data revealed that 7l exerted antiproliferative activity mainly by regulating cell cycle, DNA replication and p53 signaling pathway. Indeed, compound 7l induced G2/M phase arrest by AURKB transcription inhibition and resulted in cell apoptosis via p53 signaling pathway. Most importantly, compound 7l demonstrated potent antitumor activity in A549 xenograft tumor model. Collectively, 7l might be a promising lead compound for the development of new therapeutic agents for AURKB overexpressed or mutated cancers.

Recent drug design strategies and identification of key heterocyclic scaffolds for promising anticancer targets

Cancer, a noncommunicable disease, is the leading cause of mortality worldwide and is anticipated to rise by 75% in the next two decades, reaching approximately 25 million cases. Traditional cancer treatments, such as radiotherapy and surgery, have shown limited success in reducing cancer incidence. As a result, the focus of cancer chemotherapy has switched to the development of novel small molecule antitumor agents as an alternate strategy for combating and managing cancer rates. Heterocyclic compounds are such agents that bind to specific residues in target proteins, inhibiting their function and potentially providing cancer treatment. This review focuses on privileged heterocyclic pharmacophores with potent activity against carbonic anhydrases and kinases, which are important anticancer targets. Evaluation of ongoing pre-clinical and clinical research of heterocyclic compounds with potential therapeutic value against a variety of malignancies as well as the provision of a concise summary of the role of heterocyclic scaffolds in various chemotherapy protocols have also been discussed. The main objective of the article is to highlight key heterocyclic scaffolds involved in recent anticancer drug design that demands further attention from the drug development community to find more effective and safer targeted small-molecule anticancer agents.

Design, Synthesis and Biological Evaluation of 6-(Imidazo[1,2-a]pyridin-6-yl)quinazoline Derivatives as Anticancer Agents via PI3Kα Inhibition

Aberrant expression of the phosphatidylinositol 3-kinase (PI3K) signalling pathway is often associated with tumourigenesis, progression and poor prognosis. Hence, PI3K inhibitors have attracted significant interest for the treatment of cancer. In this study, a series of new 6-(imidazo[1,2-a]pyridin-6-yl)quinazoline derivatives were designed, synthesized and characterized by 1H NMR, 13C NMR and HRMS spectra analyses. In the in vitro anticancer assay, most of the synthetic compounds showed submicromolar inhibitory activity against various tumour cell lines, among which 13k is the most potent compound with IC50 values ranging from 0.09 μΜ to 0.43 μΜ against all the tested cell lines. Moreover, 13k induced cell cycle arrest at G2/M phase and cell apoptosis of HCC827 cells by inhibition of PI3Kα with an IC50 value of 1.94 nM. These results suggested that compound 13k might serve as a lead compound for the development of PI3Kα inhibitor.