Quinoline-Based Molecules Targeting c-Met, EGF, and VEGF Receptors and the Proteins Involved in Related Carcinogenic Pathways

Efficacy of graphene quantum dot-hyaluronic acid nanocomposites containing quinoline for target therapy against cancer cells

The study aims to assess the impact of graphene quantum dot-hyaluronic acid-quinoline nanocomposites (GQD-HA-Qu NCs) on MCF-7, HT-29, A2780, PANC-1, and HeLa cell lines. The GQD-HA-Qu NCs were characterized using dynamic light scattering (DLS), field emission scanning electron microscopy (FESEM), and Fourier-transform infrared (FTIR) spectroscopy. MTT assays and flow cytometry evaluated the cytotoxic and apoptotic effects of synthesized NCs. Additionally, real-time PCR was utilized to assess apoptotic gene expression. The DLS assay revealed a particle size of 224.96 nm with a polydispersity index (PDI) of 0.3. The FESEM analysis also confirmed the uniform spherical morphology of NCs. The MTT assessment demonstrated significant cytotoxicity in all cell lines, with MCF-7 and A2780 exhibiting pronounced sensitivity (P < 0.001). The flow cytometry analyses also revealed a dose-dependent increase in late apoptosis at higher concentrations of GQD-HA-Qu NCs. Notably, p53 expression was significantly upregulated compared to the untreated cells (P < 0.01), while caspases 8 and 9 showed no substantial change. This finding indicates that the p53 pathway is predominant in mediating GQD-HA-Qu NCs-induced apoptosis. The present study suggests that GQD-HA-Qu NCs are a promising treatment with selective cytotoxicity against cancer cells and robust antioxidant activity. These findings warrant further investigation for potential clinical applications.

Synthesis of novel quinoline-thiazolobenzimidazolone hybrids as anticancer agents through caspase-dependent apoptosis

AIM

This work explores the synthesis of new bi-heterocyclic hybrid compounds based on quinoline ring and investigates their potential as anticancer agents.

MATERIALS & METHODS

The novel fused quinoline-thiazolo[3,2-a] benzimidazole-3(2 h)one hybrids were prepared by regioselective nucleophilic ring opening of the corresponding quinolinyl-oxiranes. In vitro cytotoxic activity was evaluated against human lung (A549) and gastric (AGS) cancer cell lines.

RESULTS

Global results showed that all tested compounds have promising inhibitory properties. Compounds 17 and 18 bearing two methoxy groups on the quinoline ring have exhibited remarkable and interesting activities. The investigation of the cell death process showed that these compounds activated a caspase-dependent apoptosis pathway. Results were further supported by molecular docking studies.

CONCLUSION

Both compounds exhibited good drug-like characteristics, which make them promising drug candidates.

Design, Synthesis, and In Silico Insights of new 4-Piperazinylquinolines as Antiproliferative Agents against NCI Renal Cancer Cell Lines

In the search for new anticancer compounds, quinoline and piperazine moieties represent the most promising pharmacophoric fragments for the development of more effective drugs. A particularly interesting approach in medicinal chemistry is molecular hybridization, where different known components are integrated into a single chemical entity, resulting in hybrid molecules with enhanced biological activity. In this study, we have developed a new series of 4-(4-benzoylpiperazin-1-yl)-6-nitroquinoline-3-carbonitrile compounds (8 a-l), with potential anticancer effect, by combining the quinoline, the piperazinyl and the benzoylamino moieties. The rationalized compounds (8 a-l) were first evaluated in silico to assess the ADMET and drug-likeness profiles, synthesized using appropriate synthetic strategies and then tested in vitro under the National Cancer Institute DTP-NCI60 program. The entire series exhibited potent anticancer activity against the renal cell carcinoma (RCC) cell line UO-31, with compounds 8 c and 8 g effectively inhibiting cancer cell growth without excessive cytotoxic effects (growth percentages of -7 and -19, respectively). In silico induced fit docking (IFD) and molecular dynamics (MD) studies provided further insights into the putative mechanisms of action for both compounds, which were predicted to strongly bind key oncogenic proteins involved in RCC progression. The promising in vitro and in silico results herein presented provide a solid foundation for the development of a new series of small heterocyclic molecules with anticancer activity.

Clioquinol inhibits angiogenesis by promoting VEGFR2 degradation and synergizes with AKT inhibition to suppress triple-negative breast cancer vascularization

Inhibition of angiogenesis, either as monotherapy or in conjunction with other treatments, holds significant promise in cancer treatment. However, the limited efficacy of clinically approved anti-angiogenic agents underscores the urgent need for the development of novel drugs and therapeutic strategies. In this study, we demonstrate the highly selective inhibitory effects of clioquinol, a topical antifungal and antibiotic agent, on the angiogenic activity of endothelial cells (ECs) in a series of in vitro angiogenesis assays. Moreover, clioquinol effectively suppressed blood vessel formation in ex vivo aortic ring and in vivo Matrigel plug assays. Mechanistic studies revealed that clioquinol directly binds to the ATP-binding site of vascular endothelial growth factor receptor 2 (VEGFR2), promoting its degradation through both proteasome and lysosome pathways. This led to the down-regulation of the downstream extracellular signal-regulated kinase (ERK) pathway. In addition, the combination with the AKT inhibitor MK-2206 synergistically boosted the anti-angiogenic efficacy of clioquinol in vitro and in an in vivo dorsal skinfold chamber model of triple-negative breast cancer (TNBC), leading to the suppression of TNBC growth. Accordingly, clioquinol, either alone or in combination with AKT inhibitors, represents a promising therapeutic agent for future anti-angiogenic cancer treatment.

Quinoline analogs: multifaceted heterocyclic compounds with varied synthetic strategies and potent antitubercular properties

Tuberculosis cases have continuously increased by 64% over the last nine years, from 2014 to 2023. Approximately 33% of the global population is affected by TB. It is a bacterial disease, and Mycobacterium tuberculosis is the most common bacteria that affects the lungs of human beings during the infection. Other hazardous bacterial species causing tuberculosis are M. pinnipedii, M. canettii, M. caprae, M. bovis, M. africanum, and M. microti. TB symptoms in TB-infected patients include fever, chest pain, weight loss, and fatigue. Depending on the stage of infection, the treatment for TB can take approximately six months to two years. Quinoline comprises a pyridine ring fused with a benzene ring, and both these rings share two adjacent carbon atoms and can take part in electrophilic substitution reactions. Quinoline-based heterocyclic compounds are attracting substantial interest owing to their vital role as a class of synthetic and natural molecules. Quinoline and its derivatives display various biological activities, including anti-TB, anticonvulsant, antibiotic, antifungal, antimalarial, antipsychotic, antihypertensive, antileishmanial, antioxidant, tyrosine kinase inhibitory, anti-inflammatory, anticancer, anti-asthmatic, cardiotonic, anthelmintic, antiprotozoal, anti-HIV, and anti-Alzheimer effects. Some fused analogs of quinoline, such as graveolinine, ciprofloxacin, kokusaginine, bedaquiline, levofloxacin, moxifloxacin, and mefloquine, are commercially available as antitubercular drugs. There are various methods available to synthesize quinoline-containing antitubercular drugs. In this review paper, we present three types of synthetic methods in which substituted quinolines, substituted anilines, and miscellaneous starting materials are used and outline MIC values for all the synthesized compounds to signify their anti-TB activity.

Novel Quinoline Nitrate Derivatives: Synthesis, Characterization, and Evaluation of their Anticancer Activity with a Focus on Molecular Docking and NO Release

BACKGROUND

Nitric Oxide (NO) has recently gained recognition as a promising approach in the field of cancer therapy. The quinoline scaffold is pivotal in cancer drug research and is known for its versatility and diverse mechanisms of action.

OBJECTIVE

This study presents the synthesis, characterization, and evaluation of novel quinoline nitrate derivatives as potential anticancer agents.

METHODS

The compounds were synthesized through a multi-step process involving the preparation of substituted 1-(2-aminophenyl) ethan-1-one, followed by the synthesis of substituted 2- (chloromethyl)-3,4-dimethylquinolines, and finally, the formation of substituted (3,4- dimethylquinolin-2-yl) methyl nitrate derivatives. The synthesized compounds were characterized using various spectroscopic techniques. Molecular docking studies were conducted to assess the binding affinity of the compounds to the EGFR tyrosine kinase domain.

RESULTS

The docking scores revealed varying degrees of binding affinity, with compound 6k exhibiting the highest score. The results suggested a correlation between molecular docking scores and anticancer activity. Further evaluations included MTT assays to determine the cytotoxicity of the compounds against Non-Small Cell Lung Cancer (A-549) and pancreatic cancer (PANC-1) cell lines. Compounds with electron-donating groups displayed notable anticancer potential, and there was a correlation between NO release and anticancer activity. The study also investigated nitric oxide release from the compounds, revealing compound 6g as the highest NO releaser.

CONCLUSION

The synthesized quinoline nitrate derivatives showed promising anticancer activity, with compound 6g standing out as a potential lead compound. The correlation between molecular docking, NO release, and anticancer activity suggests the importance of specific structural features in the design of effective anticancer agents.

Novel Antibacterial 4-Piperazinylquinoline Hybrid Derivatives Against Staphylococcus aureus: Design, Synthesis, and In Vitro and In Silico Insights

Molecular hybridization, which consists of the combination of two or more pharmacophores into a single molecule, is an innovative approach in drug design to afford new chemical entities with enhanced biological activity. In the present study, this strategy was pursued to develop a new series of 6,7-dimethoxy-4-piperazinylquinoline-3-carbonitrile derivatives (5a-k) with potential antibiotic activity by combining the quinoline, the piperazinyl, and the benzoylamino moieties, three recurrent frameworks in antimicrobial research. Initial in silico evaluations were conducted on the designed compounds, highlighting favorable ADMET and drug-likeness properties, which were synthesized through a multistep strategy, isolated, and fully characterized. The whole set was tested in vitro against Staphylococcus aureus ATCC 25923 and Pseudomonas aeruginosa ATCC 10145 representative Gram-positive and Gram-negative strains, respectively. Notably, 5k exhibited potent and selective activity against S. aureus (MIC 10 μM), with a dose- and time-dependent response and capability to affect cell membrane integrity. On the other hand, no significant activity was observed against P. aeruginosa. Further in silico docking and molecular dynamics studies highlighted strong interactions of 5k with bacterial enzymes, such as tyrosyl-tRNA synthetase, pyruvate kinase, and DNA gyrase B, suggesting potential modes of action. These findings underscore the value of the hybridization approach in producing new antimicrobial agents, guiding future optimization for broader-spectrum activity.

Targeting c-Met in breast cancer: From mechanisms of chemoresistance to novel therapeutic strategies

Breast cancer presents a significant challenge due to its heterogeneity and propensity for developing chemoresistance, particularly in the triple-negative subtype. c-Mesenchymal epithelial transition factor (c-Met), a receptor tyrosine kinase, presents a promising target for breast cancer therapy due to its involvement in disease progression and poor prognosis. However, the heterogeneous expression of c-Met within breast cancer subtypes and individual tumors complicates targeted therapy. Also, cancer cells can develop resistance to c-Met inhibitors through various mechanisms, including bypass signaling pathways and genetic mutations. The off-target effects of c-Met inhibitors further limit their clinical utility, necessitating the development of more selective agents. To overcome these challenges, personalized treatment approaches and combination therapies are being explored to improve treatment efficacy while minimizing adverse effects. Novel c-Met inhibitors with improved selectivity and reduced off-target toxicity show promise in preclinical studies. Additionally, targeted delivery systems aim to enhance drug localization and reduce systemic toxicity. Future directions involve refining inhibitor design and integrating c-Met inhibition into personalized treatment regimens guided by molecular profiling. This review explores the mechanisms by which c-Met contributes to chemoresistance in breast cancer and current challenges in targeting c-Met for breast cancer therapy. It discusses strategies to optimize treatment outcomes, ultimately improving patient prognosis and reducing mortality rates associated with this devastating disease.

Design, synthesis, and biological evaluation of novel quinoline-based EGFR/HER-2 dual-target inhibitors as potential anti-tumor agents

Dual targeting of EGFR and HER2 is a valid anti-cancer approach for treating solid tumors. We designed and synthesized a new series of EGFR/HER-2 dual-target inhibitors based on quinoline derivatives. The structure of the newly synthesized compounds was verified using 1H NMR, 13C NMR, and elemental analysis. The targeted compounds were tested for antiproliferative efficacy against four cancer cell lines. All the compounds had GI50s ranging from 25 to 82 nM, with breast (MCF-7) and lung (A-549) cancer cell lines being the most sensitive. Compound 5a demonstrated the most significant antiproliferative action. With inhibitory (IC50) values of 71 and 31 nM, respectively, compound 5a proved to be the most effective dual-target inhibitor of EGFR and HER-2, outperforming the reference erlotinib (IC50 = 80 nM) as an EGFR inhibitor but falling short of the clinically used agent lapatinib (IC50 = 26 nM) as a HER2 inhibitor. The apoptotic potential activity of 5a was examined, and the findings demonstrated that 5a promotes apoptosis by activating caspase-3, 8, and Bax while simultaneously reducing the expression of the anti-apoptotic protein Bcl-2. The docking studies provided valuable insights into the binding interactions of compounds 3e and 5a with EGFR, effectively rationalizing the observed SAR trends.

An insight into sustainable and green chemistry approaches for the synthesis of quinoline derivatives as anticancer agents

Quinolones, a key class of heterocyclics, are gaining popularity among organic and medicinal chemists due to their promising properties. Quinoline, with its broad spectrum of action, plays a primordial role in chemotherapy for cancer. Drugs include lenvatinib and its structural derivatives carbozantinib and bosutinib, and tipifarnib are the popular anticancer agents. Owing to the importance of quinoline, there are several classical methods for the synthesis such as, such as Gould-Jacobs, Conrad-Limpach, Camps cyclization, Skraup, Doebnervon Miller, Combes, Friedlander, Pfitzinger, and Niementowski synthesis. These methods are well-commended for developing an infinite variety of quinoline analogues. However, these procedures are associated with several drawbacks such as long reaction times, use of hazardous chemicals or stoichiometric proportions, difficulty of working up conditions, high temperatures, organic solvents, and the presence of numerous steps, all of which have an impact on the environment and the economy. As a result, researchers are working hard to develop green quinoline compounds in the hopes of making groundbreaking discoveries in the realm of cancer. In this review, we have highlighted significant research on quinoline-based compounds and their structure-activity relationship (SAR). Furthermore, because of the significant economic and environmental health and safety (EHS) concerns, more research is being dedicated to the green synthesis of quinolone derivatives. The current review offers recent advances in quinoline derivatives as anticancer agents for green synthesis using microwave, ultrasound, and one-pot synthesis. We believe that our findings will provide useful insight and inspire more green research on this framework to produce powerful and selective quinoline derivatives.

Unlocking c-MET: A comprehensive journey into targeted therapies for breast cancer

Breast cancer is the most common malignancy among women, posing a formidable health challenge worldwide. In this complex landscape, the c-MET (cellular-mesenchymal epithelial transition factor) receptor tyrosine kinase (RTK), also recognized as the hepatocyte growth factor (HGF) receptor (HGFR), emerges as a prominent protagonist, displaying overexpression in nearly 50% of breast cancer cases. Activation of c-MET by its ligand, HGF, secreted by neighboring mesenchymal cells, contributes to a cascade of tumorigenic processes, including cell proliferation, metastasis, angiogenesis, and immunosuppression. While c-MET inhibitors such as crizotinib, capmatinib, tepotinib and cabozantinib have garnered FDA approval for non-small cell lung cancer (NSCLC), their potential within breast cancer therapy is still undetermined. This comprehensive review embarks on a journey through structural biology, multifaceted functions, and intricate signaling pathways orchestrated by c-MET across cancer types. Furthermore, we highlight the pivotal role of c-MET-targeted therapies in breast cancer, offering a clinical perspective on this promising avenue of intervention. In this pursuit, we strive to unravel the potential of c-MET as a beacon of hope in the fight against breast cancer, unveiling new horizons for therapeutic innovation.

Saturation Transfer Difference NMR and Molecular Docking Interaction Study of Aralkyl-Thiodigalactosides as Potential Inhibitors of the Human-Galectin-3 Protein

Human Galectin-3 (hGal-3) is a protein that selectively binds to β-galactosides and holds diverse roles in both normal and pathological circumstances. Therefore, targeting hGal-3 has become a vibrant area of research in the pharmaceutical chemistry. As a step towards the development of novel hGal-3 inhibitors, we synthesized and investigated derivatives of thiodigalactoside (TDG) modified with different aromatic substituents. Specifically, we describe a high-yielding synthetic route of thiodigalactoside (TDG); an optimized procedure for the synthesis of the novel 3,3'-di-O-(quinoline-2-yl)methyl)-TDG and three other known, symmetric 3,3'-di-O-TDG derivatives ((naphthalene-2yl)methyl, benzyl, (7-methoxy-2H-1-benzopyran-2-on-4-yl)methyl). In the present study, using competition Saturation Transfer Difference (STD) NMR spectroscopy, we determined the dissociation constant (Kd) of the former three TDG derivatives produced to characterize the strength of the interaction with the target protein (hGal-3). Based on the Kd values determined, the (naphthalen-2-yl)methyl, the (quinolin-2-yl)methyl and the benzyl derivatives bind to hGal-3 94, 30 and 24 times more strongly than TDG. Then, we studied the binding modes of the derivatives in silico by molecular docking calculations. Docking poses similar to the canonical binding modes of well-known hGal-3 inhibitors have been found. However, additional binding forces, cation-π interactions between the arginine residues in the binding pocket of the protein and the aromatic groups of the ligands, have been established as significant features. Our results offer a molecular-level understanding of the varying affinities observed among the synthesized thiodigalactoside derivatives, which can be a key aspect in the future development of more effective ligands of hGal-3.

Synthesis and biological evaluation of novel 2-morpholino-4-anilinoquinoline derivatives as antitumor agents against HepG2 cell line

Cancer is a life-threatening illness all over the world, and developing anticancer treatments with high efficacy and low side effects remains a challenge. The quinoline ring structure has long been recognized as a flexible nucleus in the design and synthesis of physiologically active chemicals. In this study, five new 2-morpholino-4-anilinoquinoline compounds were synthesized and their biological anticancer potential against the HepG2 cell line was assessed. The compounds produced demonstrated varying responses against HepG2 cells, with compounds 3c, 3d, and 3e exhibiting the highest activity, with IC50 values of 11.42, 8.50, and 12.76 μM, respectively. It is a critical requirement that anticancer medications are able to selectively decrease cancer growth while not causing damage to normal cells. Compound 3e exhibited increased activity while maintaining adequate selectivity. It was also the most effective chemical against cell migration and adhesion, which could play an important role in drug resistance and cell metastasis. In total, the findings revealed good possibilities for anticancer therapy, suggesting a target for future development of anticancer medication.

Design, synthesis and anticancer evaluation of novel arylhydrazones of active methylene compounds

Nerve growth factor (NGF) and its receptor, tropomyosin kinase receptor kinase type A (TrkA) is emerging as an important target for Glioblastoma (GBM) treatment. TrkA is the cancer biomarker majorly involved in tumor invasion and migration into nearby normal tissue. However, currently, available Trk inhibitors exhibit many adverse effects in cancer patients, thus demanding a novel class of ligands to regulate Trk signaling. Here, we exploited the role of TrkA (NTRK1) expression from the 651 datasets of brain tumors. RNA sequence analysis identified overexpression of NTRK1 in GBM, recurrent GBM as well in Oligoastrocytoma patients. Also, TrkA expression tends to increase over the higher grades of GBM. TrkA protein targeting hydrazone derivatives, R48, R142, and R234, were designed and their mode of interaction was studied using molecular docking and dynamic simulation studies. Ligands' stability and binding assessment reveals R48, 2 2-(2-(2-hydroxy-4-nitrophenyl) hydrazineylidene)-1-phenylbutane-1,3-dione, as a potent ligand that interacts well with TrkA's hydrophobic residues, Ile, Phe, Leu, Ala, and Val. R48- TrkA exhibits stable binding potentials with an average RMSD value <0.8 nm. R48 obeyed Lipinski's rule of five and possessed the best oral bioavailability, suggesting R48 as a potential compound with drug-likeness properties. In-vitro analysis also revealed that R48 exhibited a higher cytotoxicity effect for U87 GBM cells than TMZ with the IC50 value of 68.99 μM. It showed the lowest percentage of cytotoxicity to the non-cancerous TrkA expressing MEF cells. However, further SiRNA analysis validates the non-specific binding of R48, necessitating structural alteration for the development of R48-based TrkA inhibitor for GBM therapeutics.

Small Molecule Inhibitors Targeting the "Undruggable" Survivin: The Past, Present, and Future from a Medicinal Chemist's Perspective

Survivin, a homodimeric protein and a member of the IAP family, plays a vital function in cell survival and cycle progression by interacting with various proteins and complexes. Its expression is upregulated in cancers but not detectable in normal tissues. Thus, it has been regarded and validated as an ideal cancer target. However, survivin is "undruggable" due to its lack of enzymatic activities or active sites for small molecules to bind/inhibit. Academic and industrial laboratories have explored different strategies to overcome this hurdle over the past two decades, with some compounds advanced into clinical testing. These strategies include inhibiting survivin expression, its interaction with binding partners and homodimerization. Here, we provide comprehensive analyses of these strategies and perspective on different small molecule survivin inhibitors to help drug discovery targeting "undruggable" proteins in general and survivin specifically with a true survivin inhibitor that will prevail in the foreseeable future.

Design and biological evaluation of 3-substituted quinazoline-2,4(1H,3H)-dione derivatives as dual c-Met/VEGFR-2-TK inhibitors

The dual c-Met/vascular endothelial growth factor receptor 2 (VEGFR-2) TK inhibition is a good strategy to overcome therapeutic resistance to small molecules VEGFR-2 inhibitors. In this study, we designed 3-substituted quinazoline-2,4(1H,3H)-dione derivatives as dual c-Met/VEGFR-2 TK inhibitors. We introduced new synthetic methods for reported derivatives of 3-substituted quinazoline-2,4(1H,3H)-dione 2a-g, in addition to the preparation of some new derivatives namely, 3 and 4a-j. Three compounds namely, 2c, 4b, and 4e showed substantial amount of inhibition for both c-Met and VEGFR-2 TK (IC₅₀ range 0.052-0.084 µM). Both compounds 4b, 4e showed HB with highly conserved residue Asp1222 in the HB region of c-Met TK. For VEGFR-2 TK, compound 4b showed HB with a highly conserved residue Asp1046 in the HB region. Compound 4e showed HB with Glu885 and Asp1046. Moreover, in silico prediction of pharmacokinetic and physicochemical parameters of target compounds was carried out using SwissADME website. The quinazoline-2,4(1H,3H)-dione derivatives are promising antiproliferative candidates that require further optimisation.HighlightsNew 3-substituted quinazoline-2,4(1H,3H)-dione derivatives were synthesised and characterised.Compounds 4b and 4e showed higher cytotoxic activity than cabozantinib against HCT-116 colorectal cell lines.Both compounds 4b and 4e showed less toxicity to WI38 normal cell line compared to HCT 116 colon cancer cell line.Compound 4b was superior to cabozantinib in VEGFR-2 inhibition while compound 2c was equipotent to cabozantinib.Compounds 4b and 4e showed remarkable c-Met inhibitory activity.Compounds 4b and 4e arrested cell cycle and induced significant levels of apoptosis.In silico ADME prediction revealed high oral bioavailability and enhanced water solubility of target compounds as compared to cabozantinib.Target compounds interacted with both c-Met and VEGFR-2 active site in similar way to cabozantinib.

Design and Synthesis of Novel Thieno[3,2-c]quinoline Compounds with Antiproliferative Activity on RET-Dependent Medullary Thyroid Cancer Cells

RET kinase gain-of-function mutations represent the main cause of the high aggressiveness and invasiveness of medullary thyroid cancer (MTC). The selective inhibition of the RET kinase is a suitable strategy for the treatment of this endocrine neoplasia. Herein, we performed an innovative ligand-based virtual screening protocol using the DRUDITonline web service, focusing on the RET kinase as a biological target. In this process, thieno[3,2-c]quinolines 6a-e and 7a-e were proposed as new potential RET inhibitors. The selected compounds were synthetized by appropriate synthetic strategies, and in vitro evaluation of antiproliferative properties conducted on the particularly aggressive MTC cell line TT(C634R) identified compounds 6a-d as promising anticancer agents, with IC50 values in the micromolar range. Further structure-based computational studies revealed a significant capability of the most active compounds to the complex RET tyrosine kinase domain. The interesting antiproliferative results supported by in silico predictions suggest that these compounds may represent a starting point for the development of a new series of small heterocyclic molecules for the treatment of MTC.

New proapoptotic chemotherapeutic agents based on the quinolone-3-carboxamide scaffold acting by VEGFR-2 inhibition

In the current study, we designed and synthesized a series of new quinoline derivatives 10a-p as antiproliferative agents targeting cancer through inhibition of VEGFR-2. Preliminary molecular docking to assess the interactions of the designed derivatives with the binding site of VEGFR-2 (PDB code: 4ASD) displayed binding poses and interactions comparable to sorafenib. The synthesized compounds exhibited VEGFR-2 inhibitory activity with IC50 ranging from 36 nM to 2.23 μM compared to sorafenib (IC50 = 45 nM), where derivative 10i was the most potent. Additionally, the synthesized derivatives were evaluated in vitro for their cytotoxic activity against HepG2 cancer cell line. Seven compounds 10a, 10c, 10d, 10e, 10i, 10n and 10o (IC50 = 4.60, 4.14, 1.07, 0.88, 1.60, 2.88 and 2.76 μM respectively) displayed better antiproliferative activity than sorafenib (IC50 = 8.38 μM). Compound 10i was tested against Transformed Human Liver Epithelial-2 normal cell line (THLE-2) to evaluate its selective cytotoxicity. Furthermore, 10i, as a potent representative of the series, was assayed for its apoptotic activity and cell cycle kinetics' influence on HepG2, its effects on the gene expression of VEGFR-2, and protein expression of the apoptotic markers Caspase-7 and Bax. Compound 10i proved to have a potential role in apoptosis by causing significant increase in the early and late apoptotic quartiles, a remarkable activity in elevating the relative protein expression of Bax and Caspase-7 and a significant reduction of VEGFR-2 gene expression. Collectively, the obtained results indicate that compound 10i has a promising potential as a lead compound for the development of new anticancer agents.

Mutational pattern off homologous recombination repair (HRR)-related genes in upper tract urothelial carcinoma

BACKGROUND

Homologous recombination (HR) repair (HRR) has been indicated to be a biomarker for immunotherapy, chemotherapy, and poly-ADP ribose polymerase inhibitors inhibitors (PARPis). Nonetheless, their molecular correlates in upper tract urothelial carcinoma (UTUC) have not been well studied. This study aimed to explore the molecular mechanism and tumor immune profile of HRR genes and the relevance of their prognostic value in patients with UTUC.

MATERIALS AND METHODS

One hundred and ninety-seven tumors and matched blood samples from Chinese UTUC were subjected to next-generation sequencing. A total of 186 patients from The Cancer Genome Atlas were included. Comprehensive analysis was performed.

RESULTS

In Chinese patients with UTUC, 5.01% harbored germline HRR gene mutations, and 1.01% had Lynch syndrome-related genes. A total of 37.6% (74/197) of patients carried somatic or germline HRR gene mutations. There was marked discrepancy in the mutation landscapes, genetic interactions, and driver genes between the HRR-mut cohorts and HRR-wt cohorts. Aristolochic acid signatures and defective DNA mismatch repair signatures only existed in individuals in the HRR-mut cohorts. Inversely, the unknown signature (signature A) and signature SBS55 only existed in patients in the HRR-wt cohorts. HRR gene mutations regulated immune activities by NKT cells, plasmacytoid dendritic cells, hematopoietic stem cell, and M1 macrophages. In patients with local recurrence, patients with HRR gene mutations had poorer DFS rates than patients with wild-type HRR genes.

CONCLUSIONS

Our results imply that the detection of HRR gene mutations can predict recurrence in patients with UC. In addition, this study provides a path to explore the role of HRR-directed therapies, including PARPis, chemotherapy, and immunotherapy.

Iron-Catalyzed Oxidative Cyclization of 2-Amino Styrenes with Alcohols and Methyl Arenes for the Synthesis of Polysubstituted Quinolines

Herein, we present the iron-catalyzed oxidative cyclization of alcohol/methyl arene with 2-amino styrene to synthesize polysubstituted quinoline. Low-oxidation level substrates such as alcohols and methyl arenes are converted to aldehydes in the presence of an iron catalyst and di-t-butyl peroxide. Then, the quinoline scaffold is synthesized through imine condensation/radical cyclization/oxidative aromatization. Our protocol showed a broad substrate scope, and various functionalization and fluorescence applications of quinoline products demonstrated its synthetic ability.

Sulfonylated Indeno[1,2-c]quinoline Derivatives as Potent EGFR Tyrosine Kinase Inhibitors

The epidermal growth factor receptor (EGFR) has been considered a potential target for lung cancer therapy due to its essential role in regulating the survival and proliferation of cancer cells. Although erlotinib, a potent EGFR tyrosine kinase (EGFR-TK) inhibitor, has been used as the first-line drug for lung cancer treatment, acquired drug resistance caused by the T790M secondary mutation of EGFR-TK inevitably develops after a median response duration of 9-13 months. Thus, the search for promising compounds to effectively target EGFR-TK has become an imperative necessity. In this study, the kinase inhibitory activities of a series of sulfonylated indeno[1,2-c]quinolines (SIQs) against EGFR-TK were experimentally and theoretically investigated. Among the 23 SIQ derivatives studied, eight compounds showed enhanced EGFR-TK inhibitory activity (IC₅₀ values of ca. 0.6-10.2 nM) compared to the known drug erlotinib (IC₅₀ of ∼20 nM). In a cell-based assay in human cancer cell lines with EGFR overexpression (A549 and A431 cells), the eight selected SIQs all showed more significant cytotoxicity against A431 than A549 cells, consistent with the higher EGFR expression in A431 cells. Molecular docking and FMO-RIMP2/PCM calculations revealed that SIQ17 occupies the ATP-binding site of EGFR-TK, where its sulfonyl group is mainly stabilized by C797, L718, and E762 residues. Triplicate 500 ns molecular dynamics (MD) simulations also confirmed the binding strength of SIQ17 in complex with EGFR. Overall, the potent SIQ compounds obtained in this work could be further optimized for developing novel anticancer drug candidates targeting EGFR-TK.

Integrating a phenotypic screening with a structural simplification strategy to identify 4-phenoxy-quinoline derivatives to potently disrupt the mitotic localization of Aurora kinase B

We combined a mechanism-informed phenotypic screening (MIPS) assay with a structural simplification strategy to guide the discovery of compounds that disrupt the localization of the mitotic regulator, Aurora kinase B (AURKB), rather than inhibiting its catalytic activity. An initial hit 4-(4-methylthiophen-2-yl)-N-(4-(quinolin-4-yloxy)phenyl)phthalazin-1-amine was identified after screening an in-house library of small molecules and phenocopied the loss of function mutations in AURKB without inhibiting its catalytic activity. We isolated this hit compound activity to its 4-phenoxy-quinoline moiety. The fragment was further optimized into a class of new chemical entities that potently disrupt the mitotic localization of AURKB at low nanomolar concentrations and consequently elicit severe growth inhibition in diverse human cancer cell lines. A lead compound, N-(3-methoxy-5-(6-methoxyquinolin-4-yl)oxy)phenyl)acetamide possessed desirable pharmacokinetic properties such as AUC_0-∞: 227.15 [ng∙h/mL/(mg/kg)]; C_max: 3378.52 ng/mL T_1/2: 3.52 h; and F%: 42 % and produced the AURKB-inhibitory phenotypes in a mouse xenograft model. A lead compound is a powerful tool for interrogating the regulation of AURKB and has the potential to be further developed as a first-in-class oncology therapeutic.

Targeting c-Met in the treatment of urologic neoplasms: Current status and challenges

At present, studies have found that c-Met is mainly involved in epithelial-mesenchymal transition (EMT) of tumor tissues in urologic neoplasms. Hepatocyte growth factor (HGF) combined with c-Met promotes the mitosis of tumor cells, and then induces motility, angiogenesis, migration, invasion and drug resistance. Therefore, c-Met targeting therapy may have great potential in urologic neoplasms. Many strategies targeting c-Met have been widely used in the study of urologic neoplasms. Although the use of targeting c-Met therapy has a strong biological basis for the treatment of urologic neoplasms, the results of current clinical trials have not yielded significant results. To promote the application of c-Met targeting drugs in the clinical treatment of urologic neoplasms, it is very important to study the detailed mechanism of c-Met in urologic neoplasms and innovate c-Met targeted drugs. This paper firstly discussed the value of c-Met targeted therapy in urologic neoplasms, then summarized the related research progress, and finally explored the potential targets related to the HGF/c-Met signaling pathway. It may provide a new concept for the treatment of middle and late urologic neoplasms.

The Anticancer Effect of a Novel Quinoline Derivative 91b1 through Downregulation of Lumican

Quinoline derivatives have been reported to possess a wide range of pharmaceutical activities. Our group previously synthesized a series of quinoline compounds, in which compound 91b1 showed a significant anticancer effect. The purpose of this study was to evaluate the anticancer activity of compound 91b1 in vitro and in vivo, and screen out its regulated target. A series of cancer cell lines and nontumor cell lines were treated with compound 91b1 by MTS cytotoxicity assay and cell-cycle assay. In vivo anticancer activity was evaluated by a xenografted model on nude mice. Target prediction of 91b1 was assessed by microarray assay and confirmed by pancancer analysis. Relative expression of the target gene Lumican was measured by qRT-PCR. 91b1 significantly reduced tumor size in the nude mice xenograft model. Lumican was downregulated after 91b1 treatment. Lumican was proven to increase tumorigenesis in vivo, as well as cancer cell migration, invasion, and proliferation in vitro. The results of this study suggest that the anticancer activity of compound 91b1 probably works through downregulating the gene Lumican.

Synthesis, Biocidal and Antibiofilm Activities of New Isatin-Quinoline Conjugates against Multidrug-Resistant Bacterial Pathogens along with Their In Silico Screening

Isatin-quinoline conjugates 10a-f and 11a-f were assembled by the reaction of N-(bromobutyl) isatin derivatives 3a, b with aminoquinolines 6a-c and their corresponding hydrazinyl 9a-c in good yields. The structures of the resulting conjugates were established by spectroscopic tools and showed data consistent with the proposed structures. In vitro antibacterial activity against different bacterial strains was evaluated. All tested conjugates showed significant biocidal activity with lower MIC than the first line drugs chloramphenicol and ampicillin. Conjugates 10a, 10b and 10f displayed the most potent activity against all clinical isolates. The antibiofilm activity for all tested conjugates was screened against the reference drug vancomycin using the MRSA strain. The results revealed that all conjugates had an inhibitory activity against biofilm formation and conjugate. Conjugate 11a showed 83.60% inhibition at 10 mg/mL. In addition, TEM studies were used to prove the mechanism of antibacterial action of conjugates 10a and 11a against (MRSA). Modeling procedures were performed on 10a-f and 11a-f and interestingly the results were nearly consistent with the biological activities. In addition, in silico pharmacokinetic evaluation was performed and revealed that the synthesized compounds 10a-f and 11a-f were considered drug-like molecules with promising bioavailability and high GI absorption. The results confirmed that the title compounds caused the disruption of bacterial cell membranes and could be used as potential leads for the further development and optimization of antibacterial agents.

Domino Nitro Reduction-Friedländer Heterocyclization for the Preparation of Quinolines

The Friedländer synthesis offers efficient access to substituted quinolines from 2-aminobenzaldehydes and activated ketones in the presence of a base. The disadvantage of this procedure lies in the fact that relatively few 2-aminobenzaldehyde derivatives are readily available. To overcome this problem, we report a modification of this process involving the in situ reduction of 2-nitrobenzaldehydes with Fe/AcOH in the presence of active methylene compounds (AMCs) to produce substituted quinolines in high yields. The conditions are mild enough to tolerate a wide range of functionality in both reacting partners and promote reactions not only with phenyl and benzyl ketones, but also with β-keto-esters, β-keto-nitriles, β-keto-sulfones and β-diketones. The reaction of 2-nitroaromatic ketones with unsymmetrical AMCs is less reliable, giving a competitive formation of substituted quinolin-2(1H)-ones from the cyclization of the Z Knoevenagel intermediate which appears to be favored when certain large groups are adjacent to the AMC ketone carbonyl.

Computational targeting of allosteric site of MEK1 by quinoline-based molecules

MEK1 is an attractive target due to its role in selective extracellular-signal-regulated kinase phosphorylation, which plays a pivotal role in regulating cell proliferation. Another benefit of targeting the MEK protein is its unique hydrophobic pocket that can accommodate highly selective allosteric inhibitors. To date, various MEK1 inhibitors have reached clinical trials against several cancers, but they were discarded due to their severe toxicity and low efficacy. Thus, the development of allosteric inhibitors for MEK1 is the demand of the hour. In this in-silico study, molecular docking, long-term molecular dynamics (5 µs), and molecular mechanics Poisson-Boltzmann surface area analysis were undertaken to address the potential of quinolines as allosteric inhibitors. We selected four reference MEK1 inhibitors for the comparative analysis. The drug-likeness and toxicity of these molecules were also examined based on their ADMET and Toxicity Prediction by Komputer Assisted Technology profiles. The outcome of the analysis revealed that the quinolines (4m, 4o, 4s, and 4n) exhibited better stability and binding affinity while being nontoxic compared to reference inhibitors. We have reached the conclusion that these quinoline molecules could be checked by experimental studies to validate their use as allosteric inhibitors against MEK1.

New quinoxalin-2(1H)-one-derived VEGFR-2 inhibitors: Design, synthesis, in vitro anticancer evaluations, in silico ADMET, and docking studies

More than 70% of cancer patients who are treated with chemotherapeutics do not show a durable response. As part of the global plan seeking new effective chemotherapeutics, here, we report the synthesis and in vitro and computational studies of new lenvatinib and sorafenib analog quinoxalines as vascular endothelial growth factor receptor II (VEGFR-2) tyrosine kinase inhibitors. The central quinolone and pyridine moieties of the Food and Drug Administration-approved anticancer agents lenvatinib and sorafenib were replaced with the versatile quinoxaline scaffold that has been exploited for developing potent cytotoxic agents. With some minor structural optimizations, all the other pharmacophoric features of lenvatinib and sorafenib were maintained. Accordingly, three new sets of quinoxalines were synthesized to evaluate their activity against liver, colorectal, and breast malignancies. The results obtained in the in vitro cytotoxicity evaluation study revealed the superior activity of three derivatives (20, 25, and 29) compared with that of doxorubicin and sorafenib. Absorption, distribution, metabolism, excretion, and toxicity (ADMET) profiling and docking of 20, 25, and 29 into the VEGFR-2 receptor were also performed. Results of in silico studies showed the potential of the designed compounds to bind effectively with a number of key residues. The obtained in vitro cytotoxic activity and ADMET profiles of compounds 20, 25, and 29 suggested that they should be subjected to further structural optimizations to develop new candidates in cancer treatment protocols.

Structure-based pharmacophore mapping and virtual screening of natural products to identify polypharmacological inhibitor against c-MET/EGFR/VEGFR-2

Three receptor tyrosine kinases (RTKs), c-MET, EGFR, and VEGFR-2 have been identified as potential oncogenic targets involved in tumor development, metastasis, and invasion. Designing inhibitors that can simultaneously interact with multiple targets is a promising approach, therefore, inhibiting these three RTKs with a single chemical component might give an effective chemotherapeutic strategy for addressing the disease while limiting adverse effects. The in-silico methods have been developed to identify the polypharmacological inhibitors particularly for drug repurposing and multitarget drug design. Here, to find a viable inhibitor from natural source against these three RTKs, structure-based pharmacophore mapping and virtual screening of SN-II database were carried out. The filtered compound SN00020821, identified as Cedeodarin, from different computational approaches, demonstrated good interactions with all the three targets, c-MET/EGFR/VEGFR-2, with interaction energies of -42.35 kcal/mol, -49.32 kcal/mol and -44.83 kcal/mol, respectively. SN00020821displayed stable key interactions with critical amino acids of all the three receptors' kinase catalytic domains including "DFG motif" explored through the MD simulations. Furthermore, it also met the ADMET requirements and was determined to be drug-like as predicted from the Lipinski's rule of five and Veber's rule. Finally, SN00020821 provides a novel molecular scaffold that could be investigated further as a polypharmacological anticancer therapeutic candidate that targets the three RTKs.Communicated by Ramaswamy H. Sarma.

Recent advances in chemistry and therapeutic potential of functionalized quinoline motifs – a review

Quinoline, which consists of benzene fused with N-heterocyclic pyridine, has received considerable attention as a core template in drug design because of its broad spectrum of bioactivity. This review aims to present the recent advances in chemistry, medicinal potential and pharmacological applications of quinoline motifs to unveil their substantial efficacies for future drug development. Essential information in all the current and available literature used was accessed and retrieved using different search engines and databases, including Scopus, ISI Web of Knowledge, Google and PUBMED. Numerous derivatives of the bioactive quinolines have been harnessed via expeditious synthetic approaches, as highlighted herein. This review reveals that quinoline is an indisputable pharmacophore due to its tremendous benefits in medicinal chemistry research and other valuable areas of human endeavour. The recent in vivo and in vitro screening reported by scientists is highlighted herein, which may pave the way for novel drug development. Owing to the array of information available and highlighted herein on the medicinal potential of quinoline and its functionalized derivatives, a new window of opportunity may be opened to medicinal chemists to access more biomolecular quinolines for future drug development.

Quinoline, which consists of benzene fused with N-heterocyclic pyridine, has received considerable attention as a core template in drug design because of its broad spectrum of bioactivity.

Dictamnine, a novel c-Met inhibitor, suppresses the proliferation of lung cancer cells by downregulating the PI3K/AKT/mTOR and MAPK signaling pathways

Dictamnine (Dic), a naturally occurring small-molecule furoquinoline alkaloid isolated from the root bark of Dictamnus dasycarpus Turcz., is reported to display anticancer properties. However, little is known about the direct target proteins and anticancer mechanisms of Dic. In the current study, Dic was found to suppress the growth of lung cancer cells in vitro and in vivo, and to attenuate the activation of PI3K/AKT/mTOR and mitogen-activated protein kinase (MAPK) signaling pathways by inhibiting the phosphorylation and activation of receptor tyrosine kinase c-Met. Moreover, the binding of Dic to c-Met was confirmed by using cellular thermal shift assay (CETSA) and drug affinity responsive target stability (DARTS) assay. Among all cancer cell lines tested, Dic inhibited the proliferation of c-Met-dependent EBC-1 cells with the greatest potency (IC50 = 2.811 μM). Notably, Dic was shown to synergistically improve the chemo-sensitivity of epidermal growth factor receptor-tyrosine kinase inhibitor (EGFR-TKI)-resistant lung cancer cells to gefitinib and osimertinib. These results suggest that Dic is a c-Met inhibitor that can serve as a potential therapeutic agent in the treatment of lung cancer, especially against EGFR TKI-resistant and c-Met-dependent lung cancer.

Green electro-organic synthesis of a novel catechol derivative based on o-benzoquinone nucleophilic addition

In this work, a green-electrochemical synthesis was applied to catechol oxidation (1) to o-benzoquinone (2) using cyclic voltammetry and potential controlled coulometry.

Issues of origin, morphology and clinical significance of tumor microvessels in gastric cancer

Gastric cancer (GC) remains a serious oncological problem, ranking third in the structure of mortality from malignant neoplasms. Improving treatment outcomes for this pathology largely depends on understanding the pathogenesis and biological characteristics of GC, including the identification and characterization of diagnostic, prognostic, predictive, and therapeutic biomarkers. It is known that the main cause of death from malignant neoplasms and GC, in particular, is tumor metastasis. Given that angiogenesis is a critical process for tumor growth and metastasis, it is now considered an important marker of disease prognosis and sensitivity to anticancer therapy. In the presented review, modern concepts of the mechanisms of tumor vessel formation and the peculiarities of their morphology are considered; data on numerous factors influencing the formation of tumor microvessels and their role in GC progression are summarized; and various approaches to the classification of tumor vessels, as well as the methods for assessing angiogenesis activity in a tumor, are highlighted. Here, results from studies on the prognostic and predictive significance of tumor microvessels in GC are also discussed, and a new classification of tumor microvessels in GC, based on their morphology and clinical significance, is proposed for consideration.

Amidine- and Amidoxime-Substituted Heterocycles: Synthesis, Antiproliferative Evaluations and DNA Binding

The novel 1,2,3-triazolyl-appended N- and O-heterocycles containing amidine 4–11 and amidoxime 12–22 moiety were prepared and evaluated for their antiproliferative activities in vitro. Among the series of amidine-substituted heterocycles, aromatic diamidine 5 and coumarine amidine 11 had the most potent growth-inhibitory effect on cervical carcinoma (HeLa), hepatocellular carcinoma (HepG2) and colorectal adenocarcinoma (SW620), with IC₅₀ values in the nM range. Although compound 5 was toxic to non-tumor HFF cells, compound 11 showed certain selectivity. From the amidoxime series, quinoline amidoximes 18 and 20 showed antiproliferative effects on lung adenocarcinoma (A549), HeLa and SW620 cells emphasizing compound 20 that exhibited no cytostatic effect on normal HFF fibroblasts. Results of CD titrations and thermal melting experiments indicated that compounds 5 and 10 most likely bind inside the minor groove of AT-DNA and intercalate into AU-RNA. Compounds 6, 9 and 11 bind to AT-DNA with mixed binding mode, most probably minor groove binding accompanied with aggregate binding along the DNA backbone.

A simple and efficient copper-catalyzed three-component reaction to synthesize (Z)-1,2-dihydro-2-iminoquinolines

A operationally simple synthesis of (Z)-1,2-dihydro-2-iminoquinolines that proceeds under mild conditions is achieved by copper-catalyzed reaction of 1-(2-aminophenyl)ethan-1-ones, sulfonyl azides and terminal ynones. In particular, the reaction goes through a base-free CuAAC/ring-opening process to obtain the Z-configured products due to hydrogen bonding.

Design and green synthesis of novel quinolinone derivatives of potential anti-breast cancer activity against MCF-7 cell line targeting multi-receptor tyrosine kinases

A new set of 4,6,7,8-tetrahydroquinolin-5(1H)-ones were designed as cytotoxic agents against breast cancer cell line (MCF-7) and synthesised under ultrasonic irradiation using chitosan decorated copper nanoparticles (CS/CuNPs) catalyst. The new compounds 4b, 4j, 4k, and 4e exhibited the most potent cytotoxic activity of IC₅₀ values (0.002 − 0.004 µM) comparing to Staurosporine of IC₅₀; 0.005 μM. The latter derivatives exhibited a promising safety profile against the normal human WI38 cells of IC₅₀ range 0.0149 − 0.048 µM. Furthermore, the most promising cytotoxic compounds 4b, 4j were evaluated as multi-targeting agents against the RTK protein kinases; EGFR, HER-2, PDGFR-β, and VEGFR-2. Compound 4j showed promising inhibitory activity against HER-2 and PDGFR-β of IC₅₀ values 0.17 × 10⁻³, 0.07 × 10⁻³ µM in comparison with the reference drug sorafenib of IC₅₀; 0.28 × 10⁻³, 0.13 × 10⁻³ µM, respectively. In addition, 4j induced apoptotic effect and cell cycle arrest at G2/M phase preventing the mitotic cycle in MCF-7 cells.

Quinoline anticancer agents active on DNA and DNA-interacting proteins: From classical to emerging therapeutic targets

Quinoline is one of the most important and versatile nitrogen heterocycles embodied in several biologically active molecules. Within the numerous quinolines developed as antiproliferative agents, this review is focused on compounds interfering with DNA structure or with proteins/enzymes involved in the regulation of double helix functional processes. In this light, a special focus is given to the quinoline compounds, acting with classical/well-known mechanisms of action (DNA intercalators or Topoisomerase inhibitors). In particular, the quinoline drugs amsacrine and camptothecin (CPT) have been studied as key lead compounds for the development of new agents with improved PK and tolerability properties. Moreover, notable attention has been paid to the quinoline molecules, which are able to interfere with emerging targets involved in cancer progression, as G-quadruplexes or the epigenetic ones (e.g.: histone deacetylase, DNA and histones methyltransferase). The antiproliferative and the enzymatic inhibition data of the reviewed compounds have been analyzed. Furthermore, concerning the SAR (structure-activity relationship) aspects, the most recurrent ligand-protein interactions are summarized, underling the structural requirements for each kind of mechanism of action.