Design, synthesis, and biological evaluation of 6-(imidazo[1,2-a] pyridin-6-yl) quinazolin-4(3H)-one derivatives as potent anticancer agents by dual targeting Aurora kinase and ROR1

Structure-directing optimization of N-(2,3-dihydrobenzo[b] [1,4]dioxin-6-yl)benzamide derivatives as selective receptor tyrosine kinase-like orphan receptor 1 (ROR1) inhibitors for cancer therapy

Receptor tyrosine kinase-like orphan receptor 1 (ROR1) is an attractive therapeutic target for various cancers, including leukemia and lung cancer. Although some biological agents have entered clinical trials and several small-molecule inhibitors have been developed, selective ROR1 inhibitors remain underexplored. In our previous studies, we identified LDR102, an indole derivative, as a ROR1 inhibitor with favorable binding affinity and potent antitumor efficacy. However, LDR102 exhibited moderate ROR1 inhibitory activity and "off-target" effects on other kinases, such as c-Kit and AblT315I, limiting its further development. To address these limitations, we optimized LDR102 and synthesized a series of N-(2,3-dihydrobenzo[b][1,4]dioxin-6-yl)benzamide derivatives as selective ROR1 inhibitors, culminating in the identification of compound 9i, which possesses favorable ROR1 inhibitory activity, good selectivity, and potent anti-tumor activity in vivo and in vitro.

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.

Optimization of 1-Methyl-3-(pyridin-3-yl)-1H-indol Derivatives as ROR1 Inhibitors with Improved Activity and Selectivity

ROR1 has garnered significant attention as a therapeutic target in oncology due to its critical involvement in cancer malignancy. Several biologics targeting ROR1 have advanced to clinical trials, but the development of selective small-molecule inhibitors remains limited. In our previous work, we identified the indole-based LDR102 as a novel ROR1 inhibitor with promising antitumor efficacy. However, subsequent studies revealed its off-target activity against kinases such as c-Kit, AblT315I, and PDGFRαV561D, alongside suboptimal pharmacokinetic (PK) profiles. To address these limitations, we pursued a systematic optimization campaign focused on LDR102's scaffold. This effort produced a series of 1-methyl-3-(pyridin-3-yl)-1H-indole derivatives, culminating in the discovery of compound 24d. This lead candidate demonstrates exceptional ROR1 inhibitory potency, high selectivity, robust antitumor activity in vitro and in vivo, and an optimized PK profile, marking a substantive advance toward selective ROR1 inhibitors.

Novel macromolecule CPD4 suppresses cell proliferation and metastasis of triple-negative breast cancer by targeting ROR1 protein

Breast cancer is the second most common cancer among women in the US, with triple-negative breast cancer (TNBC) accounting for 15-20 % of new diagnoses. TNBC cells lack estrogen and progesterone receptors, and human epidermal growth factor receptor 2, which makes them resistant to standard hormone treatments. Current therapies like chemotherapy and radiation often harm both cancerous and healthy cells, underscoring the need for developing new targeted treatments. ROR1, an oncoprotein that is overexpressed in various cancers, including breast cancer, is minimally present in normal tissues. Targeting ROR1 signaling has been shown to trigger apoptosis and reduce TNBC cell proliferation. A novel macromolecule compound, CPD4, was discovered through in-silico docking for its ability to bind and inhibit the pseudokinase domain of ROR1. In vitro evidence revealed that CPD4 decreases cell viability and induces apoptosis in TNBC cell lines at concentrations of 2-10 μM, while leaving normal breast cells unharmed. CPD4 also blocks migration, invasion, and causes G2/M-phase arrest in TNBC cells. Its mechanism of action involves reducing key downstream markers of ROR1 signaling, particularly the phosphorylation of AKT/GSK3β. In 3D spheroid cultures, CPD4 reduces the size of TNBC spheroids. Moreover, the combination treatment of CPD4 and the standard chemotherapy docetaxel exhibits synergistic efficacy against different TNBC cell lines with a combination index below 0.01. These results suggest that CPD4 holds promise as a therapeutic option for TNBC and could potentially benefit other cancers with ROR1 overexpression.

Advances in the design, discovery, and optimization of aurora kinase inhibitors as anticancer agents

INTRODUCTION

Aurora kinases (AKs) play key roles during carcinogenesis and show a close relationship with many cellular effects including mitotic entry, spindle assembly and chromosomal alignment biorientation. Indeed, elevated levels of AKs have been reported in several different tumor types, leading research scientists to investigate ways that we can target AKs for the purpose of developing new anticancer therapeutics.

AREA COVERED

This review examines the design, discovery, and development of Aurora kinase inhibitors (AKIs) as anticancer agents and delineates their roles in cancer progression or development. Various databases like PubMed, Scopus, Google scholar, SciFinder were used to search the relevant information. This article provides a comprehensive overview of recent advances in the medicinal chemistry of AKIs including the candidates under clinical development and list of patents filed. In addition, their mechanistic findings, SARs, and in silico studies have also been discussed to offer prospects in this field.

EXPERT OPINION

The integration of artificial intelligence and computational approaches is poised to accelerate the development of AKIs as anticancer agents. However, the associated challenges currently hindering its impact in drug development must be overcome before drugs can successfully translate from early drug development into clinical practice.

Discovery of the first potent ROR1 degrader for the treatment of non-small cell lung cancer

ROR1 has been identified as a pseudokinase, functioning as an allosteric regulator in tumor progression. Aberrant overexpression of ROR1 has been observed in various malignancies, highlighting its potential as therapeutic target for cancer therapy. Modulation of ROR1 by proteolysis targeting chimera degrader instead of traditional inhibitor could offer great efficiency in blocking its kinase-independent regulatory function. Here, we report the first potent ROR1 degraders constructed by connecting the E3 ligand to a ROR1 binder. One representative compound 11d exhibited remarkable efficacy in depleting ROR1 protein with a DC50 value of 40.88 nM and Dmax of 93.7 %. Mechanistic investigations illuminated that compound 11d triggers ROR1 protein degradation in a ubiquitin proteasome system (UPS)-dependent manner. Additionally, compound 11d displayed a significantly enhanced ability to inhibit ROR1 signaling, induce apoptosis, and suppress proliferation in lung cell lines compared to the warhead ROR1 binder. These findings underscore the substantial potential of ROR1 degrader for the treatment of non-small cell lung cancer (NSCLC) cells.

A prodrug nanodevice co-delivering docetaxel and ROR1 siRNA for enhanced triple negative breast cancer therapy

Triple-negative breast cancer (TNBC) has been a clinical challenge due to its high recurrence and metastasis rates. Chemotherapy remains the primary treatment for TNBC after surgery ablation, but it lacks targeted specificity and causes side effects in normal tissues. Receptor tyrosine kinase-like orphan receptor 1 (ROR1) is significantly expressed in TNBC cells, and small interference RNA (siRNA) targeting ROR1 can effectively suppress ROR1 gene expression, thereby inhibiting proliferation and metastasis. However, clinical application of ROR1 siRNA is limited by susceptibility to clearance and difficulty in endosomal escape. In this study, the docetaxel (DTX) prodrug nanoparticle BBRM delivering ROR1 siRNA was constructed. The BBRM could be effectively internalized by tumor cells and endosomal escape to release DTX and ROR1 siRNA. In 4T1 tumor-bearing mice, BBRM could be targeting delivered to tumor and lung tissues, with good biosafety, achieving a tumor inhibition rate of 74.1 % and inhibiting lung metastasis. By integrating chemotherapy and RNA interference therapy, BBRM successfully co-delivered chemotherapeutic agents and siRNA to improve the therapeutic efficacy of triple-negative breast cancer and provided a promising strategy for clinical transformation. STATEMENT OF SIGNIFICANCE: Chemotherapy is still the primary treatment for triple-negative breast cancer (TNBC) after surgery ablation, but it causes side effects without targeting capacity. ROR1 is significantly expressed in TNBC cells, and RNA interference for ROR1 can suppress ROR1 gene expression to inhibit tumor proliferation. However, as oligonucleotides, effect of ROR1 siRNA is limited by susceptibility to clearance and difficulty in endosomal escape. In this work, we designed a nanodevice based on a docetaxel (DTX) prodrug that targets ROR1 for the synergistic therapy of TNBC. We constructed a nanoparticle (BBRM) for co-delivery of the DTX and ROR1 siRNA. The BBRM could be effectively internalized by tumor cells and endosomal escape. The ROR1 siRNA downregulated ROR1 protein expression and improved the anti-proliferative and anti-metastatic effects. In addition, BBRM reversed the immunosuppressive tumor microenvironment, thus improving breast cancer therapeutic efficacy. It was a pioneering investigation in synergistic chemo-gene therapy by co-delivering DTX and ROR1 siRNA for TNBC treatment.

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.

Discovery of Novel Receptor Tyrosine Kinase-like Orphan Receptor 1 (ROR1) Inhibitors for Cancer Treatment

Receptor tyrosine kinase-like orphan receptor 1 (ROR1) is an oncogenic membrane protein in several malignancies and has been considered an attractive target for the treatment of human cancers. In this study, structure-based virtual screening and structure optimization were conducted to identify novel ROR1 inhibitors. Based on hit compound 2, 45 novel ROR1 inhibitors were designed and synthesized, and the detailed structure-activity relationship was investigated. Representative compound 19h potently binds ROR1 with a KD value of 0.10 μM, exhibiting antitumor activity in lung cancer and breast cancer cell lines (IC50: 0.36-1.37 μM). Additionally, a mechanism investigation demonstrated that compound 19h induces the apoptosis of tumor cells. Importantly, compound 19h significantly suppressed tumor growth in a mouse model without obvious toxicity. Overall, this work identified compound 19h as a new ROR1 inhibitor, providing a novel lead compound for the treatment of lung cancer and breast cancer.

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.

Imidazopyridine-based kinase inhibitors as potential anticancer agents: A review

Considering the fundamental role of protein kinases in the mechanism of protein phosphorylation in critical cellular processes, their dysregulation, especially in cancers, has underscored their therapeutic relevance. Imidazopyridines represent versatile scaffolds found in abundant bioactive compounds. Given their structural features, imidazopyridines have possessed pivotal potency to interact with different protein kinases, inspiring researchers to carry out numerous structural variations. In this comprehensive review, we encompass an extensive survey of the design and biological evaluations of imidazopyridine-based small molecules as potential agents targeting diverse kinases for anticancer applications. We describe the structural elements critical to inhibitory potency, elucidating their key structure-activity relationships (SAR) and mode of actions, where available. We classify these compounds into two groups: Serine/threonine and Tyrosine inhibitors. By highlighting the promising role of imidazopyridines in kinase inhibition, we aim to facilitate the design and development of more effective, targeted compounds for cancer treatment.