Dual or multi-targeting inhibitors: The next generation anticancer agents

Design, synthesis, and biological evaluation of novel CDK4/6 and BRD4 dual inhibitors for treatment of KRAS-mutant NSCLC

CDK4/6 is the candidate therapeutic target for KRAS-mutant NSCLC. However, its frequent primary and acquired resistance limits its potential clinical application. Recently it had been shown that BRD4 up-regulation induced conferred resistance of KRAS-mutant NSCLC cells to CDK4/6 inhibitor, and BRD4 inhibitor synergized with CDK4/6 inhibitor induced senescence in KRAS-mutant NSCLC tumors and cells, meanwhile, the combined therapy extended survival of the KRAS-mutant NSCLC mouse model. Thus, a series of CDK4/6 and BRD4 dual inhibitors were prepared to target KRAS-mutant NSCLC. Among these compounds, PJ2 exhibited potent antiproliferative effects against KRAS-mutant NSCLC cells NCI-H358 (IC50 = 0.34 ± 0.01 μM) and A549 (IC50 = 0.31 ± 0.04 μM), and had excellent inhibitory effects on CDK4, CDK6, BRD4(BD1) and BRD4(BD2), and IC50 values were 168.75 ± 46.32 nM, 292.45 ± 11.67 nM, 23.17 ± 3.61 nM and 3.12 ± 0.15 nM, respectively. Mechanism research indicated that PJ2 induced cell cycle arrest, senescence and apoptosis through ROS-mediated DNA damage. Furthermore, PJ2 could effectively suppress the migration and invasion of NCI-H358 cells. These results proved that developing potent CDK4/6 and BRD4 dual inhibitors was a promising strategy for the KRAS-mutant NSCLC therapy.

Preparation and evaluation of a novel albumin-binding heterodimer therapeutic radiopharmaceutical with remarkable tumor accumulation and retention

The intricate heterogeneity exhibited across diverse tumor types and the inconsistent expression levels of a specific receptor within tumors make it difficult for single-targeting radiotracers to meet clinical needs. The combination of "dual-targeting" and "albumin-binding" strategies can overcome it and effectively improve tumor uptake and retention of radiopharmaceuticals, thereby enhancing the effect of tumor theranostics. In this study, an albumin binder-conjugated heterodimeric precursor L21 targeting integrin αvβ3 and CD13 was successfully developed and labeled with 68Ga and 177Lu to evaluate therapeutic potential in BxPC-3 xenograft mice. In vitro, [68Ga]Ga-L21 and [177Lu]Lu-L21 exhibited excellent radiochemical stability in phosphate buffered saline (PBS) or fetal bovine serum (FBS) at 37 °C for 5 h. Compared to [68Ga]Ga-L00 without albumin binder, the introduction of albumin binder did not substantially alter the water solubility of [68Ga]Ga-L21, but substantially increased its affinity for serum albumin in FBS. In vivo, [68Ga]Ga-L21 showed significantly higher tumor uptake and longer tumor retention time than [68Ga]Ga-L00 (0.70 ± 0.06 standardized uptake value [SUV] vs. 0.33 ± 0.02 SUV at 3 h, P = 0.0004). [177Lu]Lu-L21 exhibited excellent tumor uptake, tumor-to-nontumor ratios and tumor retention, with tumor uptake keeping 2.79 ± 0.30 percentage of injected radioactive dose per gram of tissue (%ID/g) even at 96 h post-injection. Biodistribution results of [177Lu]Lu-L21 were consistent with SPECT imaging, demonstrating that [177Lu]Lu-L21 is a promising radiopharmaceutical for tumor radionuclide therapy.

Advances of dual inhibitors based on ALK for the treatment of cancer

Anaplastic lymphoma kinase (ALK), which encodes a highly conserved receptor tyrosine kinase (RTK), is important for the development and progression of many tumors, especially non-small cell lung cancer (NSCLC). Currently, third-generation ALK inhibitors are used to treat ALK-mutant NSCLC, but the rapid emergence of resistance during treatment greatly limits their efficacy in clinic. In comparison to single-target inhibitors, ALK dual inhibitors offer the benefits of reducing the emergence of drug resistance, improving treatment efficacy, and optimizing pharmacokinetic features due to the synergistic function of ALK and other associated targets involved in tumor progression. Therefore, we outline the development of ALK dual inhibitors, highlight their design approaches and structure-activity relationship (SAR), and offer insights into new challenges and potential future directions in this area.

Design, synthesis, and biological evaluation of N-(2-amino-phenyl)-5-(4-aryl- pyrimidin-2-yl) amino)-1H-indole-2-carboxamide derivatives as novel inhibitors of CDK9 and class I HDACs for cancer treatment

The mechanisms underlying transcriptional dysregulation in tumorigenesis have received considerable attention as promising therapeutic targets to combat human cancer. Cyclin-dependent kinase 9 (CDK9) and class I histone deacetylases (HDACs) are significant therapeutic targets due to their pivotal roles in the dysregulated transcriptional programs characteristic of many cancers. Furthermore, the combinatorial transcriptional therapy with CDK9 and class I HDAC inhibitors has been shown to have a synergistic anticancer effect. In this study, a series of novel N-(2-amino-phenyl)-5-(4-aryl-pyrimidin-2-yl) amino)-1H-indole-2-carboxamide derivatives were designed and synthesized as novel dual-functional inhibitors targeting CDK9 and HDAC signaling pathways for cancer treatment. Among the synthesized compounds, 13ea demonstrated potent anti-proliferative activities (IC50 < 5.0 μM) in various cancer cell lines (HeLa, MDA-MB-231, HepG2). In addition, 13ea was found to significantly inhibit the phosphorylation function of CDK9 and the deacetylation function of class I HDACs. Furthermore, 13ea was found to inhibit the protein activity of CDK9 (IC50 = 0.17 μM), HDAC1 (IC50 = 1.73 μM), and HDAC3 (IC50 = 1.11 μM). The docking studies predicted the binding patterns of 13ea in the active pockets of CDK9 and HDAC1/3. The cellular assays revealed that 13ea induced mitochondria-related apoptosis and G2/M phase arrest in cancer cells, showing superior activities compared to those of AZD-5438 (a CDK9 inhibitor) and Mocetinostat (an inhibitor of class I HDACs). Notably, the in vivo assay demonstrated that 13ea (30 mg/kg) exhibited significant inhibition on MDA-MB-231 xenograft tumor growth, with a tumor shrinkage rate of 76.83 %. In summary, we have identified 13ea as a novel CDK9/HDAC inhibitor with excellent anticancer activity in vitro and in vivo.

Rational Method for Structural Simplification as Key Step in Hit Discovery: The Case of FGFR2 and IGF1R Dual Inhibitors

In the classic medicinal chemistry hit discovery procedure, large virtual libraries undergo different filtering and prediction steps until a small group of molecules is selected for their subsequent synthesis and biological testing. The starting molecular libraries can easily be composed of millions of molecules, hindering the selection of the most representative and promising compounds. Moreover, the resulting molecular systems tend to be overcomplex structures, hardly attainable, and often involve extrapolations of the prediction models used. We present a rational-based method to reduce the structural complexity of molecular candidates without compromising their biological activity, improving the attainability and efficiency of hit discovery. This approach has been successfully applied to identify potential tyrosine kinase dual inhibitors against Fibroblast Growth Factor Receptor 2 (FGFR2) and Insulin-Like Growth Factor 1 Receptor (IGF1R), a set of overexpressed proteins in different cancers, such as pancreatic ductal adenocarcinoma (PDAC).

Synthesis, In Vitro Evaluation, and Molecular Docking Studies of Novel 3,5-Diphenyl-1H-1,2,4-Triazole Derivatives as Potential hEGFR Inhibitors

EGFR, an important target in cancer chemotherapy, is an important component of the signaling system that regulates important cellular processes such as growth, differentiation, metabolism, and apoptosis in response to both internal and external stimuli. Based on this approach, comprehensive modeling studies targeting the EGFR protein were performed, and synthesized molecules were proposed. For this purpose, the synthesis of new 3,5-diphenyl-1H-1,2,4-triazole derivatives containing semicarbazide, thiosemicarbazide, 1,2,4-triazole-3-thione, and 1,2,4-triazole-3-one units was carried out. Among these compounds, 6a-6i presented in the present study exhibited EGFR inhibition in the nanomolar range. In addition, molecules 5e and 6e showed significant IC50 values. Compound 6e showed the closest IC50 value to gefitinib, a well-known EGFR inhibitor, with its noncompetitive inhibition mode. The Ki value of compound 6e was determined as 0.174 µM.

Recommended Tool Compounds: Thienotriazolodiazepines-Derivatized Chemical Probes to Target BET Bromodomains

Thienotriazolodiazepines, including (+)-JQ1 (4), are well-known inhibitors of the bromodomain (BD) and extra-terminal domain (BET) family of proteins. Despite the suboptimal physicochemical properties as a drug candidate, such as poor solubility and half-life, (+)-JQ1 (4) has proven as an effective chemical probe with high target potency and selectivity. (+)-JQ1 (4) and (+)-JQ1-derived chemical probes have played a vital role in chemical biology and drug discovery over the past decade, which is demonstrated by the high number of impactful research studies published since the disclosure of (+)-JQ1 (4) in 2010. In this review, we discuss the development of (+)-JQ1-derivatized chemical probes over the past decade and their significant contribution to scientific research. Specifically, we will summarize the development of innovative label-free and labeled (+)-JQ1-derivatized chemical probes, such as bivalent, covalent, and photoaffinity probes as well as protein degraders, with a focus on the design of these chemical probes.

Exploring Multi-Target Therapeutic Strategies for Glioblastoma via Endogenous Network Modeling

Medical treatment of glioblastoma presents a significant challenge. A conventional medication has limited effectiveness, and a single-target therapy is usually effective only in the early stage of the treatment. Recently, there has been increasing focus on multi-target therapies, but the vast range of possible combinations makes clinical experimentation and implementation difficult. From the perspective of systems biology, this study conducted simulations for multi-target glioblastoma therapy based on dynamic analysis of previously established endogenous networks, validated with glioblastoma single-cell RNA sequencing data. Several potentially effective target combinations were identified. The findings also highlight the necessity of multi-target rather than single-target intervention strategies in cancer treatment, as well as the promise in clinical applications and personalized therapies.

Nanohydrogel of Curcumin/Berberine Co-Crystals Induces Apoptosis via Dual Covalent/Noncovalent Inhibition of Caspases in Endometrial Cancer Cell Lines: The Synergy Between Pharmacokinetics and Pharmacodynamics

Endometrial cancer remains a significant therapeutic challenge due to drug resistance and heterogeneity. This study leverages the synergistic potential of curcumin (CUR) and berberine (BBR) co-crystals encapsulated in a nanohydrogel to address these challenges through a pharmacokinetically and pharmacodynamically targeted therapeutic strategy. The nanohydrogel formulation significantly improves the solubility, stability, and bioavailability of CUR/BBR co-crystals, optimizing their therapeutic delivery and sustained release under physiological and tumor microenvironment conditions. On the other hand, the dual inhibitory mechanism of CUR and BBR, with CUR covalently binding to the active site of caspase-3 and BBR non-covalently targeting the allosteric site, achieves enhanced apoptotic activity by disrupting both the catalytic and conformational functions of caspase-3. In vitro cytotoxicity assays demonstrate remarkable efficacy of the CUR/BBR nanohydrogel, achieving an IC50 of 12.36 μg/mL against HEC-59 endometrial cancer cells, significantly outperforming the individual components and the standard drug Camptothecin (IC50: 17.27 μg/mL). Caspase-3/7 assays confirm enhanced apoptosis induction for the nanohydrogel formulation compared to co-crystals alone and Camptothecin. Molecular dynamics simulations and binding free energy analyses further validate the synergistic interaction of CUR and BBR in their dual binding mode. This study introduces a novel therapeutic approach by enhancing drug delivery and dual targeting mechanisms, demonstrating the potential of CUR-BBR nanohydrogel as a robust therapy for EC. This strategy offers a promising platform for addressing drug resistance and improving outcomes in endometrial cancer therapy.

TClC effectively suppresses the growth and metastasis of NSCLC via polypharmacology

Despite significant advances in targeted therapies and immunotherapies, non-small cell lung cancer (NSCLC) continues to present a global health challenge, with a modest five-year survival rate of 28 %, largely due to the emergence of treatment-resistant and metastatic tumors. In response, we synthesized a novel bioactive compound, ethyl 6-chlorocoumarin-3-carboxylyl L-theanine (TClC), which significantly inhibited NSCLC growth, epithelial mesenchymal transition (EMT), migration, and invasion in vitro and tumor growth and metastasis in vivo without inducing toxicity. TClC disrupts autocrine loops that promote tumor progression, particularly in stem-like CD133-positive NSCLC (CD133+ LC) cells, which are pivotal in tumor metastasis. Through targeted molecular assays, we identified direct binding targets of TClC, including Akt, NF-κB, β-catenin, EZH2, and PD-L1. This interaction not only suppresses the expression of oncogenic factors and cancer stem cell markers but also downregulates the expression of a multidrug resistance transporter, underscoring the compound's polypharmacological potential. These results position TClC as a promising candidate for NSCLC treatment, signaling a new era in the development of cancer therapies that directly target multiple critical cancer pathways.

Protein profiling uncovers IGF-1R inhibition potential of 3-(2-furoyl)-indole scaffolds in hepatocellular carcinoma

AIM

This study investigates the anti-proliferative potential and possible molecular mechanisms of 3-(2-furoyl)-indole derivatives against HepG2.

METHOD

Identified hit compounds (4a, 4b, 4c) using MTT screening, were further investigated for their efficacy and mechanism of action through FACS studies, in-silico molecular docking, molecular dynamics (MD) simulations, and label-free quantitative proteome and ADMET prediction.

RESULTS

Lead compound 4a, showed IC50 of 27 µM against HepG2 cells and a binding score of -8.077 kcal/mol against IGF-1 R (PDB ID: 5XFS) and formed a stable complex 100 ns. Proteomic study revealed significant downregulation of the IGF-1 R downstream signaling molecules and showed minimal toxicity and favorable drug-like properties.

CONCLUSION

These findings suggest that 4a is a promising IGF-1 R inhibitor and potential drug candidate against drug resistance hepatocellular carcinoma (HCC).

Semisynthesis of Glycosmis pentaphylla Alkaloid Derivatives: Pyranoacridone-Hydroxamic Acid Cytotoxic Conjugates with HDAC and Topoisomerase II α Dual Inhibitory Activity

Inspired by our previous efforts in the semisynthetic modification of naturally occurring pyranoacridones, we report the targeted design and semisynthesis of dual inhibitors of HDAC and topoisomerase II α (Topo II α) derived from Glycosmis pentaphylla des-N-methylacronycine (1) and noracronycine (8) pyranoacridone alkaloids. Designed from the clinically approved SAHA, the cytotoxic pyranoacridone nuclei from the alkaloids served as the capping group, while a hydroxamic acid moiety functioned as the zinc-binding group. Out of 16 compounds evaluated in an in vitro cytotoxicity assay, KT32 (10c) with noracronycine (8) as the capping group and five-carbon linker hydroxamic acid side chains showed good cytotoxic activity with IC50 values of 1.0, 1.5, and 0.3 μM on MCF-7, CALU-3, and SCC-25 cell lines, respectively. KT32 (10c) showed potent HDAC inhibitory activity and partial Topo II α inhibitory activity in both enzyme assays. The SAR results strongly aligned with the predicted binding affinities from the molecular docking study. KT32 (10c) was further explored for a preliminary mechanistic understanding of SCC-25 cell lines. Flow cytometry analysis suggests that KT32 (10c) induces cell death through apoptosis, as evidenced by the substantial increase in the population of late apoptotic cells.

A review on pyrimidine-based pharmacophore as a template for the development of hybrid drugs with anticancer potential

The low efficacy and toxicity of traditional chemotherapy, led by drug resistance of targeted anticancer therapies, have mandated the exploration and development of anticancer molecules. In this league, hybrid drugs, owing to their peculiar multitargeted functionality and structural diversity, could serve as vital leads in this quest for drug discovery. They are plausibly found to offer added advantages considering the improved efficacy, low toxicity, and improved patient compliance. Among numerous heterocycles explored, pyrimidine derivatives epitomize as a valuable resource for the hybrid drug development due to their validated efficacy and versatility. The present review discusses the role of pyrimidine, a diversified pharmacophore in drug development and concepts of hybrid drugs. The study covers the recent advancements in pyrimidine-based hybrid pharmacophores. It delves further into the challenges in hybrid drug development and ongoing research in hybrid drug discovery. Furthermore, the challenges faced in developing hybrid molecules, such as their design and optimization complexities, bioavailability and pharmacokinetics issues, target identification and validation, and off-target effects, are discussed.

Structure-Based Rational Design and Evaluation of BET-Aurora Kinase Dual-Inhibitors for Treatment of Cancers

Simultaneous inhibition of the bromodomain and extra-terminal domain and Aurora kinases is a promising anticancer therapeutic strategy. Based on our previous study on BET-kinase dual inhibitors, we employed the molecular docking approach to design novel dual BET-Aurora kinase A inhibitors. Through several rounds of optimization and with the guidance of the solved cocrystal structure of BRD4 bound to inhibitor 27, we finally obtained a series of highly potent dual BET-Aurora kinase A inhibitors. Compound 38 exhibited strong affinity toward both BRD4 and Aurora kinase A. It also showed good antiproliferative activities on diverse cancer cell lines, good pharmacokinetic profiles, and favorable antitumor efficacy in renal cell cancer and colon cancer xenograft models with TGI of 45.99% and 53.06%, respectively. The development of compound 38 reinforces the concept that a rational design may achieve dual inhibitors targeting specific kinases and bromodomain proteins.

Unveiling the mechanism of action of a novel natural dual inhibitor of SARS-CoV-2 Mpro and PLpro with molecular dynamics simulations

In the twenty-first century, we have witnessed multiple coronavirus pandemics. Despite declining SARS-CoV-2 cases, continued research remains vital. We report the discovery of sydowiol B, a natural product, as a dual inhibitor of SARS-CoV-2 main protease (Mpro) and papain-like protease (PLpro). Sydowiol B interacts with the nano-channel at the Mpro dimer interface and the PLpro active site. Molecular dynamics simulations suggest that sydowiol B inhibits Mpro by limiting active site expansion rather than inducing collapse. Furthermore, sydowiol B binding may amplify the fluctuation of two loops coordinating with the structural Zn2+ in PLpro, displacing Zn2+ from the zinc finger domain to the S2 helix. Sydowiol B and its analogue, violaceol I, exhibit broad-spectrum antiviral activity against homologous coronaviruses. Given the conservation of Mpro and PLpro, sydowiol B and violaceol I are promising leads for designing and developing anti-coronavirus therapies.

Ruthenium complexes with abiraterone acetate as antiproliferative agents

This study is dedicated to the development of multimodal anticancer agents. We have obtained ruthenium complexes conjugated with the steroid-type antitumor drug abiraterone acetate in order to take advantage of the dual antitumor properties of both ruthenium and abiraterone. The compounds exhibit good antiproliferative activity against cancer cells, with selectivity over primary fibroblasts. Real-time cell analysis revealed that compound dichlorido(η6-p-cymene)(abiraterone acetate)ruthenium(II) had pronounced antiproliferation activity compared to abiraterone acetate. Flow cytometric studies on the mechanism of cell death have revealed that the most active compound induces apoptosis more effectively than abiraterone acetate. Our findings demonstrate the potential of this novel dual-action compound as promising candidates for further development as anticancer agents.

Dona Flor and her two husbands: Discovery of novel HDAC6/AKT2 inhibitors for myeloid cancer treatment

Hematological cancer treatment with hybrid kinase/HDAC inhibitors is a novel strategy to overcome the challenge of acquired resistance to drugs. We collected IC 50 datasets from the ChEMBL database for 13 cancer cell lines (72 h cytotoxicity, measured by MTT), known inhibitors for 38 kinases, and 10 HDACs isoforms, that we identified by target fishing and literature review. The data was subjected to rigorous biological and chemical curation leaving the final datasets ranging from 76 to 8173 compounds depending on the target. We generated Random Forest classification models, whereby 14 showed greater than 80% predictability after 5-fold external cross-validation. We screened 30 hybrid kinase/HDAC inhibitor analogs through each of these models. Fragment-contribution maps were constructed to aid the understanding of SARs and the optimization of these compounds as selective kinase/HDAC inhibitors for cancer treatment. Among the predicted compounds, 9 representative hybrids were synthesized and subjected to biological evaluation to validate the models. We observed high hit rates after biological testing for the following models: K562 (62.5%), MV4-11 (75.0%), MM1S (100%), NB-4 (62.5%), U937 (75.0), and HDAC6 (86.0%). This aided the identification of 6b and 6k as potent anticancer inhibitors with IC 50 of 0.2-0.8 µM in three cancer cell lines, linked to HDAC6 inhibition below 2 nM, and blockade of AKT2 phosphorylation at 2 μM, validating the ability of our models to predict novel drug candidates.

Highlights

Novel kinase/HDAC inhibitors for cancer treatment were found using machine learning61 QSAR models for hematological cancers and its targets were built and validatedK562, MV4-11, MM1S, NB-4, U937, and HDAC6 models had hit rates above 62.5% in tests 6b and 6k presented potent IC 50 of 0.2-0.8 µM in three cancer cell lines 6b and 6k inhibited HDAC6 below 2 nM, and blockade of AKT2 phosphorylation at 2 μM.

Determination of QLNC-3A6 in canine plasma by UHPLC-MS/MS and its application in pharmacokinetic studies

Multi-targeted tyrosine kinase inhibitor QLNC-3A6 Di-maleate, a structurally novel small molecule compound, has therapeutic efficacy for the treatment of canine cutaneous mast cell tumor (CMCT) caused by mutations in the c-Kit gene. Since pharmacokinetic (PK) information plays an important role in the development and application of new drugs, etc., a rapid, highly sensitive and selective UHPLC-MS/MS analytical method was developed and validated for the first time in this study for the quantitative detection of QLNC-3A6 in canine plasma. 100 µL of plasma was precipitated using 350 µL of acetonitrile, and Chromatographic separation was performed on a Phenomenex Kinetex C18 column (50 × 2.1 mm, 2.6 µm) at a flow rate of 0.4 mL/min, the mobile phases were set to 0.1% formic acid aqueous solution (A) and 0.1% formic acid acetonitrile (B). The calibration curve linear range was 0.5-100 ng/mL (R2>0.99). The intraday and interday precision values (relative standard deviation, RSD) were 2.06-13.57% and 6.90-9.14%. Intraday and interday accuracies were -10.73 to 9.54% and -3.86 to 0.70% respectively. The dilution integrity RSD value and stability RSD value were less than 3.77 and 7.45%, respectively. Subsequently, the pharmacokinetics were investigated in canine after oral administration of QLNC-3A6 Di-maleate tablets at a dose of 3 mg/kg BW using this method. The results showed that QLNC-3A6 showed fast absorption rate, rapid distribution and slow metabolic elimination in canine plasma. The results of the main PK parameters including λz, T1/2λz, Cmax, Tmax and AUClast were 0.07 ± 0.01/h, 11.00 ± 2.57 h, 50.88 ± 31.94 ng/mL, 9.08 ± 11.57 h and 836.48 ± 230.53 ng h/mL, respectively.

Advances in the design and discovery of next-generation janus kinase-2 (JAK2) inhibitors for the treatment of myeloproliferative neoplasms

INTRODUCTION

Myeloproliferative neoplasms (MPNs) are rare hematopoietic disorders driven by mutations in the JAK-STAT signaling pathway genes. While JAK2 inhibitors have transformed MPN treatment, they do not eliminate the malignant clone or prevent disease progression in most patients. This limitation underscores the need for more effective therapies.

AREA COVERED

This review examines the evolution of JAK2 inhibitors for treating MPNs. Current JAK2 inhibitors primarily function as type I inhibitors, targeting the active kinase conformation, but their effectiveness is limited by ongoing JAK-STAT signaling. To overcome these limitations, next-generation therapies, such as type II JAK2 inhibitors and pseudokinase domain inhibitors, are being developed to target inactive kinase conformations and alternative signaling pathways. Furthermore, combination therapies with PI3K, mTOR, CDK4/6 inhibitors, and epigenetic modulators are being investigated for their potential synergistic effects, aiming for deeper and more durable responses in MPN patients.

EXPERT OPINION

Next-generation JAK2 inhibitors are needed to enhance current MPNs treatments by overcoming resistance, improving selectivity, targeting specific patient groups, and exploring combination therapies. Addressing challenges in drug design, preclinical testing, and clinical trials is crucial. Developing dual or multiple inhibitors targeting JAK2 and other MPN-related pathways is urgent to address complex signaling networks and improve efficacy.

Anti-tumor and anti-metastatic effects of RRx-001 on hepatocellular carcinoma: mechanisms of action and therapeutic potential

Background

1-Bromoacetyl-3,3-dinitroazetidine (RRx-001) has potent antitumor effects, indicating its promising therapeutic potential against various cancers. This research investigates RRx-001 activity against hepatocellular carcinoma (HCC) and elucidates its underlying mechanisms.

Methods

Huh7, Hepa1-6, and MHCC97H cells were cultured and treated with varying RRx-001 concentrations for 24, 48, and 72 h. Cell viability was assessed using cell counting kit-8. The cells were divided into control and RRx-001 treatment groups at 0.5 × IC50, 1.0 × IC50, and 2.0 × IC50 concentrations for each cell line. Migration and invasion were evaluated using scratch and Transwell assays, and apoptosis was examined by apoptosis assays. RNA sequencing was performed on the Huh7 cells treated with RRx-001 for 24 h to identify differential gene expression. CD47 and TP53 protein levels were measured by Western blot. A xenograft mouse model was utilized to evaluate the effect of RRx-001 on HCC.

Results

RRx-001 inhibits HCC cell viability, migration, and invasion while inducing apoptosis, These effects are potentially mediated by the downregulation of CD47 and the upregulation of TP53, both of which modulate key signaling pathways. In vivo experiments demonstrated that RRx-001 effectively inhibits tumor growth.

Conclusion

RRx-001 reduces the viability of HCC cells and induces apoptosis. This effect may be due to the downregulation of CD47 expression and the alteration of the TP53 protein regulatory pathway.

New series of 4,6-diaryl pyrimidines: facile synthesis and antiproliferative activity as dual EGFR/VEGFR-2 inhibitors

Introduction

We developed and produced a new series of 4,6-diaryl-pyrimidines 9-29 as antiproliferative agents targeting EGFR/VEGFR-2.

Methods

The antiproliferative efficacy of the novel targets was assessed against a panel of 60 NCI cancer cell lines and four cancer cell lines in vitro.

Results and Discussion

Compounds 14, 17, 19, 22, 25, and 29 demonstrated the greatest potency among the derivatives, with GI50 values between 22 and 33 nM; compounds 22 and 29 exhibited the highest potency, with GI50 values of 22 and 24 nM, respectively. We subsequently examined the most efficient derivatives as dual EGFR/VEGFR-2 inhibitors, finding that compounds 22 and 29 functioned as dual inhibitors. Moreover, 22 and 29 can act as apoptotic inducers by increasing Bax levels and decreasing levels of the anti-apoptotic protein Bcl2. At both 24- and 48-h intervals, the cell migration rates of compounds 22 and 29 were lower than those of untreated cells, according to the migration rate and wound closure percentage assessment. The wound closure rate reached 100% after 72 h of therapy with compound 22 but only 80% with compound 29. The docking study showed that compounds 22 and 29 had docking scores similar to those of Erlotinib and Sorafenib, co-crystallized ligands, for the EGFR and VEGFR-2 proteins. The experiments on lipophilicity showed that the new pyrimidines had a consistent result. This group of compounds has better biological activity in all the biological systems studied with low lipophilicity.

Rethinking therapeutic strategies of dual-target drugs: An update on pharmacological small-molecule compounds in cancer

Oncogenes and tumor suppressors are well-known to orchestrate several signaling cascades, regulate extracellular and intracellular stimuli, and ultimately control the fate of cancer cells. Accumulating evidence has recently revealed that perturbation of these key modulators by mutations or abnormal protein expressions are closely associated with drug resistance in cancer therapy; however, the inherent drug resistance or compensatory mechanism remains to be clarified for targeted drug discovery. Thus, dual-target drug development has been widely reported to be a promising therapeutic strategy for improving drug efficiency or overcoming resistance mechanisms. In this review, we provide an overview of the therapeutic strategies of dual-target drugs, especially focusing on pharmacological small-molecule compounds in cancer, including small molecules targeting mutation resistance, compensatory mechanisms, synthetic lethality, synergistic effects, and other new emerging strategies. Together, these therapeutic strategies of dual-target drugs would shed light on discovering more novel candidate small-molecule drugs for the future cancer treatment.

Scaffold overlay of flavonoid-inspired molecules: Discovery of 2,3-diaryl-pyridopyrimidin-4-imine/ones as dual hTopo-II and tubulin targeting anticancer agents

Almost half of all medicines approved by the U.S. Food and Drug Administration have been found to be developed based on inspiration from natural products (NPs). Here, we report a novel strategy of scaffold overlaying of scaffold-hopped analogs of bioactive flavones and isoflavones and installation of drug-privileged motifs, which has led to discovery of anticancer agents that surpass the functional efficiency of the original NPs. The analogs, 2,3-diaryl-pyridopyrimidin-4-imine/ones were efficiently synthesized by an approach of a nitrile-stabilized quaternary ammonium ylide as masked synthon and Pd-catalyzed activation-arylation methods. Compared to the NPs, these NP-analogs exhibited differentiated functions; dual inhibition of human topoisomerase-II (hTopo-II) enzyme and tubulin polymerization, and pronounced antiproliferative effect against various cancer cell lines, including numerous drug-resistant cancer cells. The most active compound 5l displayed significant inhibition of migration ability of cancer cells and blocked G1/S phase transition in cell cycle. Compound 5l caused pronounced effect in expression patterns of various key cell cycle regulatory proteins; up-regulation of apoptotic proteins, Bax, Caspase 3 and p53, and down-regulation of apoptosis-inhibiting proteins, BcL-xL, Cyclin D1, Cyclin E1 and NF-κB, which indicates high efficiency of the molecule 5l in apoptosis-signal axis interfering potential. Cheminformatics analysis revealed that 2,3-diaryl-pyridopyrimidin-4-imine/ones occupy a distinctive drug-relevant chemical space that is seldom represented by natural products and good physicochemical, ADMET and pharmacokinetic-relevant profile. Together, the anticancer potential of the investigated analogs was found to be much more efficient compared to the original natural products and two anticancer drugs, Etoposide (hTopo-II inhibitor) and 5-Flurouracile (5-FU).

Computer-Aided Identification and Design of Ligands for Multi-Targeting Inhibition of a Molecular Acute Myeloid Leukemia Network

BACKGROUND/OBJECTIVES

Acute myeloid leukemia (AML) is characterized by therapeutic failure and long-term risk for disease relapses. As several therapeutic targets participate in networks, they can rewire to eventually evade single-target drugs. Hence, multi-targeting approaches are considered on the expectation that interference with many different components could synergistically hinder activation of alternative pathways and demolish the network one-off, leading to complete disease remission.

METHODS

Herein, we established a network-based, computer-aided approach for the rational design of drug combinations and de novo agents that interact with many AML network components simultaneously.

RESULTS

A reconstructed AML network guided the selection of suitable protein hubs and corresponding multi-targeting strategies. For proteins responsive to existing drugs, a greedy algorithm identified the minimum amount of compounds targeting the maximum number of hubs. We predicted permissible combinations of amiodarone, artenimol, fostamatinib, ponatinib, procaine, and vismodegib that interfere with 3-8 hubs, and we elucidated the pharmacological mode of action of procaine on DNMT3A. For proteins that do not respond to any approved drugs, namely cyclins A1, D2, and E1, we used structure-based de novo drug design to generate a novel triple-targeting compound of the chemical formula C15H15NO5, with favorable pharmacological and drug-like properties.

CONCLUSIONS

Overall, by integrating network and structural pharmacology with molecular modeling, we determined two complementary strategies with the potential to annihilate the AML network, one in the form of repurposable drug combinations and the other as a de novo synthesized triple-targeting agent. These target-drug interactions could be prioritized for preclinical and clinical testing toward precision medicine for AML.

Exploring Niclosamide as a Multi-target Drug Against SARS-CoV-2: Molecular Dynamics Simulation Studies on Host and Viral Proteins

Niclosamide has emerged as a promising repurposed drug against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). In vitro studies suggested that niclosamide inhibits the host transmembrane protein 16F (hTMEM16F), crucial for lipid scramblase activity, which consequently reduces syncytia formation that aids viral spread. Based on other in vitro reports, niclosamide may also target viral proteases such as papain-like protease (PLpro) and main protease (Mpro), essential for viral replication and maturation. However, the precise interactions by which niclosamide interacts with these multiple targets remain largely unclear. Docking and molecular dynamics (MD) simulation studies were undertaken based on a homology model of the hTMEM16F and available crystal structures of SARS-CoV-2 PLpro and Mpro. Niclosamide was observed to bind stably throughout a 400 ns MD simulation at the extracellular exit gate of the hTMEM16F tunnel, forming crucial interactions with residues spanning the TM1-TM2 loop (Gln350), TM3 (Phe481), and TM5-TM6 loop (Lys573, Glu594, and Asp596). Among the SARS-CoV-2 proteases, niclosamide was found to interact effectively with conserved active site residues of PLpro (Tyr268), exhibiting better stability in comparison to the control inhibitor, GRL0617. In conclusion, our in silico analyses support niclosamide as a multi-targeted drug inhibiting viral and host proteins involved in SARS-CoV-2 infections.

Fragment-based design and synthesis of coumarin-based thiazoles as dual c-MET/STAT-3 inhibitors for potential antitumor agents

c-MET and STAT-3 are significant targets for cancer treatments. Here, we describe a class of very effective dual STAT-3 and c-MET inhibitors with coumarin-based thiazoles (3a-o) as its scaffold. Spectroscopic evidence (NMR, HRMS, and HPLC) validated the structural discoveries of the new compounds. The cytotoxic activity of these compounds was also tested against a panel of cancer cells in accordance with US-NCI guidelines. Compound 3g proved to be active at 10 µM, thus it was automatically scheduled to be tested at five doses. Towards SNB-75 (CNS cancer cell line), compound 3g showed notable in vitro anti-cancer activity with GI50 = 1.43 μM. For the molecular targets, compound 3g displayed potent activity towards STAT-3 and c-MET having IC50 of 4.7 µM and 12.67, respectively, compared to Cabozantinib (IC50 = 15 nM of c-MET) and STAT-3-IN-3 (IC50 = 2.1 µM of STAT-3). Moreover, compound 3g significantly induced apoptosis in SNB-75 cells, causing a 3.04-fold increase in apoptotic cell death (treated cells exhibited 11.53 % overall apoptosis, against 3.04 % in reference cells) and a 3.58-fold increase in necrosis. Moreover, it arrests cells at the G2 phase. Dual inhibition of c-MET and STAT-3 protein kinase was further validated using RT-PCR. The target compound's binding mechanism was determined by the application of molecular docking.

Advances in dual-targeting inhibitors of HDAC6 for cancer treatment

Histone Deacetylase 6 (HDAC6) is an essential regulator of histone acetylation processes, exerting influence on a multitude of cellular functions such as cell motility, endocytosis, autophagy, apoptosis, and protein trafficking through its deacetylation activity. The significant implications of HDAC6 in diseases such as cancer, neurodegenerative disorders, and immune disorders have motivated extensive investigation into the development of specific inhibitors targeting this enzyme for therapeutic purposes. Single targeting drugs carry the risk of inducing drug resistance, thus prompting exploration of dual targeting therapy which offers the potential to impact multiple signaling pathways simultaneously, thereby lowering the likelihood of resistance development. While pharmacological studies have exhibited promise in combined therapy involving HDAC6, challenges related to potential drug interactions exist. In response to these challenges, researchers are investigating HDAC6 hybrid molecules which enable the concomitant targeting of HDAC6 and other key proteins, thus enhancing treatment efficacy while mitigating side effects and reducing the risk of resistance compared to traditional combination therapies. The published design strategies for dual targeting inhibitors of HDAC6 are summarized and discussed in this review. This will provide some valuable insights into more novel HDAC6 dual targeting inhibitors to meet the urgent need for innovative therapies in oncology and other related fields.

Structure-based virtual screening approach reveals natural multi-target compounds for the development of antimalarial drugs to combat drug resistance

Compared to the previous year, there has been an increase of nearly 2 million malaria cases in 2021. The emergence of drug-resistant strains of Plasmodium falciparum, the most deadly malaria parasite, has led to a decline in the effectiveness of existing antimalarial drugs. To address this problem, the present study aimed to identify natural compounds with the potential to inhibit multiple validated antimalarial drug targets. The natural compounds from the Natural Product Activity and Species Source (NPASS) database were screened against ten validated drug targets of Plasmodium falciparum using a structure-based molecular docking method. Twenty compounds, with targets ranging from three to five, were determined as the top hits. The molecular dynamics simulations of the top six complexes (NPC246162 in complex with PfAdSS, PfGDH, and PfNMT; NPC271270 in complex with PfCK, PfGDH, and PfdUTPase) confirmed their stable binding affinity in the dynamic environment. The Tanimoto coefficient and distance matrix score analysis show the structural divergence of all the hit compounds from known antimalarials, indicating minimum chances of cross-resistance. Thus, we propose further investigating these compounds in biochemical and parasite inhibition studies to reveal the real therapeutic potential. If found successful, these compounds may be a new avenue for future drug discovery efforts to combat existing antimalarial drug resistance.Communicated by Ramaswamy H. Sarma.

Selective COX-2 inhibitors as anticancer agents: a patent review (2018-2023)

INTRODUCTION

COX-2 is a crucial enzyme in the manufacture of prostaglandins. The enzyme's metabolites might have an important function as regulators of the inflammatory response and other medical conditions such as cancer. Selective COX-2 inhibitors are believed to enhance or reverse the response of cancer chemotherapeutics.

AREAS COVERED

This study addresses the chemical structures as well as the antitumor activity of new COX-2 inhibitors produced in the recent five years, aiming to provide an insight into the mechanism of COX-2 induced PGE2 powerful signal in cancer development.

EXPERT OPINION

The significance of selective COX-2 inhibitors as an efficient superfamily of compounds with anti-inflammatory, anti-Alzheimer's, anti-Parkinson's disease, and anticancer properties has piqued the passion of academics in the field of drug development. Long-term usage of selective COX-2 inhibitors, such as celecoxib has been proven in clinical trials to lower the incidence of several human malignancies. Furthermore, celecoxib has the potential to greatly increase the effectiveness of chemotherapy. Our extensive understanding of selective COX-2 inhibitor SAR may aid in the development of safer and more effective selective COX-2 inhibitors as cancer chemopreventive agents. This review focuses on the different structural classes of selective COX-2 inhibitors, with a particular emphasis on their SAR.

Design and synthesis of new 1,2,4-oxadiazole/quinazoline-4-one hybrids with antiproliferative activity as multitargeted inhibitors

Introduction

The combination of BRAF and tyrosine kinase (TK) inhibitors has been demonstrated to be highly effective in inhibiting tumor development and is an approach for overcoming resistance in clinical trials. Accordingly, a novel series of 1,2,4-oxadiazole/quinazoline-4-one hybrids was developed as antiproliferative multitargeted inhibitors.

Methods

The structures of the newly synthesized compounds 9a-o were validated using IR, NMR, MS, and elemental techniques. 9a-o were tested as antiproliferative agents.

Results and Discussion

The results showed that the majority of the tested compounds showed significant antiproliferative action with 9b, 9c, 9h, 9k, and 9l being the most potent. Compounds 9b, 9c, 9h, 9k, and 9l were tested as EGFR and BRAFV600E inhibitors. These in vitro tests revealed that compounds 9b, 9c, and 9h are strong antiproliferative agents that may act as dual EGFR/BRAFV600E inhibitors. 9b, 9c, and 9h were further investigated for their inhibitory effect on mutant EGFR (EGFRT790M), and the results showed that the tested compounds had considerable inhibitory action. Cell cycle study and apoptosis detection demonstrated that compound 9b exhibits cell cycle arrest at the G2/M transition. Molecular docking simulations reveal the binding mechanism of the most active antiproliferative agents.

Multitask Learning on Graph Convolutional Residual Neural Networks for Screening of Multitarget Anticancer Compounds

Recently, various modern experimental screening pipelines and assays have been developed to find promising anticancer drug candidates. However, it is time-consuming and almost infeasible to screen an immense number of compounds for anticancer activity via experimental approaches. To partially address this issue, several computational advances have been proposed. In this study, we present iACP-GCR, a model based on multitask learning on graph convolutional residual neural networks with two types of shortcut connections, to identify multitarget anticancer compounds. In our architecture, the graph convolutional residual neural networks are shared by all the prediction tasks before being separately customized. The NCI-60 data set, one of the most reliable and well-known sources of experimentally verified compounds, was used to develop our model. From that data set, we collected and refined data about compounds screened across nine cancer types (panels), including breast, central nervous system, colon, leukemia, nonsmall cell lung, melanoma, ovarian, prostate, and renal, for model training and evaluation. The model performance evaluated on an independent test set shows that iACP-GCR surpasses the three advanced computational methods for multitask learning. The integration of two shortcut connection types in the shared networks also improves the prediction efficiency. We also deployed the model as a public web server to assist the research community in screening potential anticancer compounds.

Recent advances in Alzheimer's disease: Mechanisms, clinical trials and new drug development strategies

Alzheimer's disease (AD) stands as the predominant form of dementia, presenting significant and escalating global challenges. Its etiology is intricate and diverse, stemming from a combination of factors such as aging, genetics, and environment. Our current understanding of AD pathologies involves various hypotheses, such as the cholinergic, amyloid, tau protein, inflammatory, oxidative stress, metal ion, glutamate excitotoxicity, microbiota-gut-brain axis, and abnormal autophagy. Nonetheless, unraveling the interplay among these pathological aspects and pinpointing the primary initiators of AD require further elucidation and validation. In the past decades, most clinical drugs have been discontinued due to limited effectiveness or adverse effects. Presently, available drugs primarily offer symptomatic relief and often accompanied by undesirable side effects. However, recent approvals of aducanumab (1) and lecanemab (2) by the Food and Drug Administration (FDA) present the potential in disrease-modifying effects. Nevertheless, the long-term efficacy and safety of these drugs need further validation. Consequently, the quest for safer and more effective AD drugs persists as a formidable and pressing task. This review discusses the current understanding of AD pathogenesis, advances in diagnostic biomarkers, the latest updates of clinical trials, and emerging technologies for AD drug development. We highlight recent progress in the discovery of selective inhibitors, dual-target inhibitors, allosteric modulators, covalent inhibitors, proteolysis-targeting chimeras (PROTACs), and protein-protein interaction (PPI) modulators. Our goal is to provide insights into the prospective development and clinical application of novel AD drugs.

Glycosylation: mechanisms, biological functions and clinical implications

Protein post-translational modification (PTM) is a covalent process that occurs in proteins during or after translation through the addition or removal of one or more functional groups, and has a profound effect on protein function. Glycosylation is one of the most common PTMs, in which polysaccharides are transferred to specific amino acid residues in proteins by glycosyltransferases. A growing body of evidence suggests that glycosylation is essential for the unfolding of various functional activities in organisms, such as playing a key role in the regulation of protein function, cell adhesion and immune escape. Aberrant glycosylation is also closely associated with the development of various diseases. Abnormal glycosylation patterns are closely linked to the emergence of various health conditions, including cancer, inflammation, autoimmune disorders, and several other diseases. However, the underlying composition and structure of the glycosylated residues have not been determined. It is imperative to fully understand the internal structure and differential expression of glycosylation, and to incorporate advanced detection technologies to keep the knowledge advancing. Investigations on the clinical applications of glycosylation focused on sensitive and promising biomarkers, development of more effective small molecule targeted drugs and emerging vaccines. These studies provide a new area for novel therapeutic strategies based on glycosylation.

Unveiling the promise of pyrimidine-modified CDK inhibitors in cancer treatment

Cyclin-dependent kinases (CDKs) constitute a vital family of protein-serine kinases, pivotal in regulating various cellular processes such as the cell cycle, metabolism, proteolysis, and neural functions. Dysregulation or overexpression of CDK kinases is directly linked to the development of cancer. However, the currently approved CDK inhibitors by the US FDA, such as palbociclib, ribociclib, Trilaciclib, Abemaciclib, etc., although effective, exhibit limited specificity and often lead to undesirable adverse effects. First and second-generation CDK inhibitors have not gained significant clinical interaction due to their high toxicity and lack of specificity. To address these challenges, a combined approach is being employed in the quest for newer CDK inhibitors aimed at mitigating toxicity and side effects associated with CDKIs. The discovery of therapeutic agents selectively targeting tumorous cells, such as CDK inhibitors, has demonstrated promise in treating various cancers, including breast cancer. Extensive literature reviews have facilitated the development of novel CDK inhibitors by combining medicinally preferred pyrimidine derivatives with other heterocyclic rings. Pyrimidine derivatives substituted with pyrazole, imidazole, benzamide, benzene sulfonamide, indole carbohydrazide, and other privileged heterocyclic rings have shown encouraging efficacy in inhibiting cyclin-dependent kinase activity. This review provides comprehensive data, including structure-activity relationship (SAR), anticancer activity, and kinetics studies of potent compounds. Additionally, molecular docking studies with compounds under clinical trial and patents filed on pyrimidine based CDK inhibitors in cancer treatment are included. This review serves as a valuable resource for further development of CDK kinase inhibitors for cancer treatment, offering insights into their efficacy, specificity, and potential clinical applications.

Research progress of multi-target HDAC inhibitors blocking the BRD4-LIFR-JAK1-STAT3 signaling pathway in the treatment of cancer

Histone deacetylase inhibitors (HDACis) show beneficial effects on different hematological malignancy subtypes. However, their impacts on treating solid tumors are still limited due to diverse resistance mechanisms. Recent studies have found that the feedback activation of BRD4-LIFR-JAK1-STAT3 pathway after HDACi incubation is a vital mechanism inducing resistance of specific solid tumor cells to HDACis. This review summarizes the recent development of multi-target HDACis that can concurrently block BRD4-LIFR-JAK1-STAT3 pathway. Moreover, our findings hope to shed novel lights on developing novel multi-target HDACis with reduced BRD4-LIFR-JAK1-STAT3-mediated drug resistance in some tumors.

Developing a Semi-Supervised Approach Using a PU-Learning-Based Data Augmentation Strategy for Multitarget Drug Discovery

Multifactorial diseases demand therapeutics that can modulate multiple targets for enhanced safety and efficacy, yet the clinical approval of multitarget drugs remains rare. The integration of machine learning (ML) and deep learning (DL) in drug discovery has revolutionized virtual screening. This study investigates the synergy between ML/DL methodologies, molecular representations, and data augmentation strategies. Notably, we found that SVM can match or even surpass the performance of state-of-the-art DL methods. However, conventional data augmentation often involves a trade-off between the true positive rate and false positive rate. To address this, we introduce Negative-Augmented PU-bagging (NAPU-bagging) SVM, a novel semi-supervised learning framework. By leveraging ensemble SVM classifiers trained on resampled bags containing positive, negative, and unlabeled data, our approach is capable of managing false positive rates while maintaining high recall rates. We applied this method to the identification of multitarget-directed ligands (MTDLs), where high recall rates are critical for compiling a list of interaction candidate compounds. Case studies demonstrate that NAPU-bagging SVM can identify structurally novel MTDL hits for ALK-EGFR with favorable docking scores and binding modes, as well as pan-agonists for dopamine receptors. The NAPU-bagging SVM methodology should serve as a promising avenue to virtual screening, especially for the discovery of MTDLs.

Synthesis, Anticancer Activity, and Molecular Docking of New 1,2,3-Triazole Linked Tetrahydrocurcumin Derivatives

Cancer is one of the deadliest diseases to humanity. There is significant progress in treating this disease, but developing some drugs that can fight this disease remains a challenge in the field of medical research. Thirteen new 1,2,3-triazole linked tetrahydrocurcumin derivatives were synthesized by click reaction, including a 1,3-dipolar cycloaddition reaction of tetrahydrocurcumin baring mono-alkyne with azides in good yields, and their in vitro anticancer activity against four cancer cell lines, including human cervical carcinoma (HeLa), human lung adenocarcinoma (A549), human hepatoma carcinoma (HepG2), and human colon carcinoma (HCT-116) were investigated using MTT(3-(4,5-dimethylthiazole-2-yl)-2,5-diphenyltetraz-olium bromide) assay. The newly synthesized compounds had their structures identified using NMR HRMS and IR techniques. Some of prepared compounds, including compounds 4g and 4k, showed potent cytotoxic activity against four cancer cell lines compared to the positive control of cisplatin and tetrahydrocurcumin. Compound 4g exhibited anticancer activity with a IC50 value of 1.09 ± 0.17 μM against human colon carcinoma HCT-116 and 45.16 ± 0.92 μM against A549 cell lines compared to the positive controls of tetrahydrocurcumin and cisplatin. Moreover, further biological examination in HCT-116 cells showed that compound 4g can arrest the cell cycle at the G1 phase. A docking study revealed that the potential mechanism by which 4g exerts its anti-colon cancer effect may be through inhabiting the binding of APC-Asef. Compound 4g can be used as a promising lead for further exploration of potential anticancer agents.

Dual-target inhibitors based on ERα: Novel therapeutic approaches for endocrine resistant breast cancer

Estrogen receptor alpha (ERα), a nuclear transcription factor, is a well-validated therapeutic target for more than 70% of all breast cancers (BCs). Antagonizing ERα either by selective estrogen receptor modulators (SERMs) or selective estrogen receptor degraders (SERDs) forms the foundation of endocrine therapy and has achieved great success in the treatment of ERα positive (ERα+) BCs. Unfortunately, despite initial effectiveness, endocrine resistance eventually emerges in up to 30% of ERα+ BC patients and remains a significant medical challenge. Several mechanisms implicated in endocrine resistance have been extensively studied, including aberrantly activated growth factor receptors and downstream signaling pathways. Hence, the crosstalk between ERα and another oncogenic signaling has led to surge of interest to develop combination therapies and dual-target single agents. This review briefly introduces the synergisms between ERα and another anticancer target and summarizes the recent advances of ERα-based dual-targeting inhibitors from a medicinal chemistry perspective. Accordingly, their rational design strategies, structure-activity relationships (SARs) and biological activities are also dissected to provide some perspectives on future directions for ERα-based dual target drug discovery in BC therapy.

Developing a Copper(II) Isopropyl 2-Pyridyl Ketone Thiosemicarbazone Compound Based on the IB Subdomain of Human Serum Albumin-Indomethacin Complex: Inhibiting Tumor Growth by Remodeling the Tumor Microenvironment

To develop a next-generation metal agent and dual-agent multitargeted combination therapy, we developed a copper (Cu) compound based on the properties of the human serum albumin (HSA)-indomethacin (IND) complex to remodel the tumor microenvironment (TME). We optimized a series of Cu(II) isopropyl 2-pyridyl ketone thiosemicarbazone compounds to obtain a Cu(II) compound (C4) with significant cytotoxicity and then constructed an HSA-IND-C4 complex (HSA-IND-C4) delivery system. IND and C4 bind to the hydrophobic cavities of the IB and IIA domains of HSA, respectively. In vivo, the HSA-IND-C4 not only showed enhanced antitumor efficacy relative to C4 and C4 + IND but also improved their targeting ability and decreased their side effects. The antitumor mechanism of C4 + IND involved acting on the different components of the TME. IND inhibited tumor-related inflammation, while C4 not only induced apoptosis and autophagy of cancer cells but also inhibited tumor angiogenesis.

Synergistic therapeutics: Co-targeting histone deacetylases and ribonucleotide reductase for enhanced cancer treatment

The development of cancer is influenced by several variables, including altered protein expression, and signaling pathways. Cancers are inherently heterogeneous and exhibit genetic and epigenetic aberrations; therefore, developing therapies that act on numerous biological targets is encouraged. To achieve this, two approaches are employed: combination therapy and dual/multiple targeting chemotherapeutics. Two enzymes, histone deacetylases (HDACs) and ribonucleotide reductase (RR), are crucial for several biological functions, including replication and repair of DNA, division of cells, transcription of genes, etc. However, it has been noted that different cancers exhibit abnormal functions of these enzymes. Potent inhibitors for each of these proteins have been extensively researched. Many medications based on these inhibitors have been successfully food and drug administration (FDA) approved, and the majority are undergoing various stages of clinical testing. This review discusses various studies of HDAC and RR inhibitors in combination therapy and dual-targeting chemotherapeutics.

1,2,4-Triazole benzamide derivative TPB against Gaeumannomyces graminis var. tritici as a novel dual-target fungicide inhibiting ergosterol synthesis and adenine nucleotide transferase function

BACKGROUND

Isopropyl 4-(2-chloro-6-(1H-1,2,4-triazol-1-yl)benzamido)benzoate (TPB) was a 1,2,4-triazole benzoyl arylamine derivative with excellent antifungal activity, especially against Gaeumannomyces graminis var. tritici (Ggt). Its mechanism of action was investigated by transmission electron microscopy (TEM) observation, assays of sterol composition, cell membrane permeability, intracellular ATP and mitochondrial membrane potential, and mPTP permeability, ROS measurement, RNA sequencing (RNA-seq) analysis.

RESULTS

TPB interfered with ergosterol synthesis, reducing ergosterol content, increasing toxic intermediates, and finally causing biomembrane disruption such as increasing cell membrane permeability and content leakage, and destruction of organelle membranes such as coarse endoplasmic reticulum and vacuole. Moreover, TPB destroyed the function of adenine nucleotide transferase (ANT), leading to ATP transport obstruction in mitochondria, inhibiting mPTP opening, inducing intracellular ROS accumulation and mitochondrial membrane potential loss, finally resulting in mitochondrial damage including mitochondria swelled, mitochondrial membrane dissolved, and cristae destroyed and reduced. RNA-seq analyses showed that TPB increased the expression of ERG11, ERG24, ERG6, ERG5, ERG3 and ERG2 genes in ergosterol synthesis pathway, interfered with the expression of genes (NDUFS5, ATPeV0E, NCA2 and Pam17) related to mitochondrial structure, and inhibited the expression of genes (WrbA and GST) related to anti-oxidative stress.

CONCLUSIONS

TPB exhibited excellent antifungal activity against Ggt by inhibiting ergosterol synthesis and destroying ANT function. So, TPB was a novel compound with dual-target mechanism of action and can be considered a promising novel fungicide for the control of wheat Take-all. The results provided new guides for the structural design of active compounds and powerful tools for pathogen resistance management. © 2023 Society of Chemical Industry.

Rational Design of PARP1/c-Met Dual Inhibitors for Overcoming PARP1 Inhibitor Resistance Induced by c-Met Overexpression

The emergence of resistance to PARP1 inhibitors poses a current therapeutic challenge, necessitating the development of novel strategies to overcome this obstacle. The present study describes the design and synthesis of a series of small molecules that target both PARP1 and c-Met. Among them, compound 16 is identified as a highly potent dual inhibitor, exhibiting excellent inhibitory activities against PARP1 (IC50 = 3.3 nM) and c-Met (IC50 = 32.2 nM), as well as demonstrating good antiproliferative effects on HR-proficient cancer cell lines and those resistant to PARP1 inhibitors. Importantly, compound 16 demonstrates superior antitumor potency compared to the PARP1 inhibitor Olaparib and the c-Met inhibitor Crizotinib, either alone or in combination, in MDA-MB-231 and HCT116OR xenograft models. These findings highlight the potential of PARP1/c-Met dual inhibitors for expanding the indications of PARP1 inhibitors and overcoming tumor cells' resistance to them.

Drug-drug conjugates of MEK and Akt inhibitors for RAS-mutant cancers

Controlling RAS mutant cancer progression remains a significant challenge in developing anticancer drugs. Whereas Ras G12C-covalent binders have received clinical approval, the emergence of further mutations, along with the activation of Ras-related proteins and signals, has led to resistance to Ras binders. To discover novel compounds to overcome this bottleneck, we focused on the concurrent and sustained blocking of two major signaling pathways downstream of Ras. To this end, we synthesized 25 drug-drug conjugates (DDCs) by combining the MEK inhibitor trametinib with Akt inhibitors using seven types of linkers with structural diversity. The DDCs were evaluated for their cell permeability/accumulation and ability to inhibit proliferation in RAS-mutant cell lines. A representative DDC was further evaluated for its effects on signaling proteins, induction of apoptosis-related proteins, and the stability of hepatic metabolic enzymes. These in vitro studies identified a series of DDCs, especially those containing a furan-based linker, with promising properties as agents for treating RAS-mutant cancers. Additionally, in vivo experiments in mice using the two selected DDCs revealed prolonged half-lives and anticancer efficacies comparable to those of trametinib. The PK profiles of trametinib and the Akt inhibitor were unified through the DDC formation. The DDCs developed in this study have potential as drug candidates for the broad inhibition of RAS-mutant cancers.

Recent advances in multitarget-directed ligands via in silico drug discovery

To combat multifactorial refractory diseases, such as cancer, cardiovascular, and neurodegenerative diseases, multitarget drugs have become an emerging area of research aimed at 'synthetic lethality' (SL) relationships associated with drug-resistance mechanisms. In this review, we discuss the in silico design of dual and triple-targeted ligands, strategies by which specific 'warhead' groups are incorporated into a parent compound or scaffold with primary inhibitory activity against one target to develop one small molecule that inhibits two or three molecular targets in an effort to increase potency against multifactorial diseases. We also discuss the analytical exploration of structure-activity relationships (SARs), physicochemical properties, polypharmacology, scaffold feature extraction of US Food and Drug Administration (FDA)-approved multikinase inhibitors (MKIs), and updates regarding the clinical status of dual-targeted chemotypes.

(E)-2-Methoxy-4-(3-(4-Methoxyphenyl) Prop-1-en-1-yl) Phenol Suppresses Breast Cancer Progression by Dual-Regulating VEGFR2 and PPARγ

In cancer treatment, multi-target approach has paid attention to a reasonable strategy for the potential agents. We investigated whether (E)-2-methoxy-4-(3-(4-methoxyphenyl) prop-1-en-1-yl) phenol (MMPP) could exert an anticancer effect by dual-regulating VEGFR2 and PPARγ. MMPP showed modulating effects in TNBC type (MDA-MB-231 and MDA-MB-468) and luminal A type (MCF7) breast cancer cell lines. MMPP enhanced PPARγ transcriptional activity and inhibited VEGFR2 phosphorylation. MMPP-induced signaling by VEGFR2 and PPARγ ultimately triggered the downregulation of AKT activity. MMPP exhibited anticancer effects, as evidenced by growth inhibition, inducement of apoptosis, and suppression of migration and invasion. At the molecular level, MMPP activated pro-apoptotic proteins (caspase3, caspase8, caspase9, and bax), while inhibiting the anti-apoptotic proteins (bcl2). Additionally, MMPP inhibited the mRNA expressions of EMT-promoting transcription factors. Therefore, our findings showed molecular mechanisms of MMPP by regulating VEGFR2 and PPARγ, and suggested that MMPP has potential to treat breast cancer.

Discovery of dual kinase inhibitors targeting VEGFR2 and FAK: structure-based pharmacophore modeling, virtual screening, and molecular docking studies

VEGFR2 and FAK signaling pathways are interconnected and have synergistic effects on tumor angiogenesis, growth, and metastasis. Thus, instead of the conventional targeting of each of these proteins individually with a specific inhibitor, the present work aimed to discover novel dual inhibitors targeting both VEGFR2 and FAK exploiting their association. To this end, receptor-based pharmacophore modeling technique was opted to generate 3D pharmacophore models for VEGFR2 and FAK type II kinase inhibitors. The generated pharmacophore models were validated by assessing their ability to discriminate between active and decoy compounds in a pre-compiled test set of VEGFR2 and FAK active compounds and decoys. ZINCPharmer web tool was then used to screen the ZINC database purchasable subset using the validated pharmacophore models retrieving 42,616 hits for VEGFR2 and 28,475 hits for FAK. Subsequently, they were filtered using various filters leaving 13,023 and 6,832 survived compounds for VEGFR2 and FAK, respectively, with 124 common compounds. Based on molecular docking simulations, thirteen compounds were found to satisfy all necessary interactions with VEGFR2 and FAK kinase domains. Thus, they are predicted to have a possible dual VEGFR2/FAK inhibitory activity. Finally, SwissADME web tool showed that compound ZINC09875266 is not only promising in terms of binding pattern to our target kinases, but also in terms of pharmacokinetic properties.

Targeted Therapeutic Strategies for the Treatment of Cancer

Extensive research is underway to develop new therapeutic strategies to counteract therapy resistance in cancers. This review presents various strategies to achieve this objective. First, we discuss different vectorization platforms capable of releasing drugs in cancer cells. Second, we delve into multitarget therapies using drug combinations and dual anticancer agents. This section will describe examples of multitarget therapies that have been used to treat solid tumors.

Combining cisplatin and a STING agonist into one molecule for metalloimmunotherapy of cancer

Mounting evidence suggests that strategies combining DNA-damaging agents and stimulator of interferon genes (STING) agonists are promising cancer therapeutic regimens because they can amplify STING activation and remodel the immunosuppressive tumor microenvironment. However, a single molecular entity comprising both agents has not yet been developed. Herein, we designed two PtIV-MSA-2 conjugates (I and II) containing the DNA-damaging chemotherapeutic drug cisplatin and the innate immune-activating STING agonist MSA-2; these conjugates showed great potential as multispecific small-molecule drugs against pancreatic cancer. Mechanistic studies revealed that conjugate I upregulated the expression of transcripts associated with innate immunity and metabolism in cancer cells, significantly differing from cisplatin and MSA-2. An analysis of the tumor microenvironment demonstrated that conjugate I could enhance the infiltration of natural killer (NK) cells into tumors and promote the activation of T cells, NK cells and dendritic cells in tumor tissues. These findings indicated that conjugate I, which was created by incorporating a Pt chemotherapeutic drug and STING agonist into one molecule, is a promising and potent anticancer drug candidate, opening new avenues for small-molecule-based cancer metalloimmunotherapy.

Breast cancer and its therapeutic targets: A comprehensive review

Breast cancer is a common and deadly disease, so there is a constant need for research to find efficient targets and therapeutic approaches. Breast cancer can be classified on a molecular and histological base. Breast cancer can be divided into ER (estrogen receptor)-positive and ER-negative, HER2 (human epidermal growth factor receptor2)-positive and HER2-negative subtypes based on the presence of specific biomarkers. Targeting hormone receptors, such as the HER2, progesterone receptor (PR), and ER, is very significant and plays a vital role in the onset and progression of breast cancer. Endocrine treatments and HER2-targeted drugs are examples of targeted therapies now being used against these receptors. Emerging immune-based medicines with promising outcomes in the treatment of breast cancer include immune checkpoint inhibitors, cancer vaccines, and adoptive T-cell therapy. It is also explored how immune cells and the tumor microenvironment affect breast cancer development and treatment response. The major biochemical pathways, signaling cascades, and DNA repair mechanisms that are involved in the development and progression of breast cancer, include the PI3K/AKT/mTOR system, the MAPK pathway, and others. These pathways are intended to be inhibited by a variety of targeted drugs, which are then delivered with the goal of restoring normal cellular function. This review aims to shed light on types of breast cancer with the summarization of different therapeutic approaches which can target different pathways for tailored medicines and better patient outcomes.

The Development of HDAC and Tubulin Dual-Targeting Inhibitors for Cancer Therapy

Histone deacetylases (HDACs) are a class of enzymes that are responsible for the removal of acetyl groups from the ε-N-acetyl lysine of histones, allowing histones to wrap DNA more tightly. HDACs play an essential role in many biological processes, such as gene regulation, transcription, cell proliferation, angiogenesis, migration, differentiation and metastasis, which make it an excellent target for anticancer drug discovery. The search for histone deacetylase inhibitors (HDACis) has been intensified, with numerous HDACis being discovered, and five of them have reached the market. However, currently available HDAC always suffers from several shortcomings, such as limited efficacy, drug resistance, and toxicity. Accordingly, dual-targeting HDACis have attracted much attention from academia to industry, and great advances have been achieved in this area. In this review, we summarize the progress on inhibitors with the capacity to concurrently inhibit tubulin polymerization and HDAC activity and their application in cancer treatment.