Pyrazolylamine Derivatives Reveal the Conformational Switching between Type I and Type II Binding Modes of Anaplastic Lymphoma Kinase (ALK)

Targeting AKT2 in MDA-MB-231 Cells by Pyrazole Hybrids: Structural, Biological and Molecular Docking Studies

Pyrazolic hybrids appended with naphthalene, p-chlorobenzene, o-phenol and toluene have been synthesized using Claisen Schmidt condensation reaction of 1-benzyl-3,5-dimethyl-1H-pyrazole-4-carbaldehyde. All compounds were characterized by various spectroscopic techniques. Compound (E)-3-(1-benzyl-3,5-dimethyl-1H-pyrazol-4-yl)-1-(4-chlorophenyl)prop-2-en-1-one crystallizes in monoclinic crystal system with C2/c space group. These synthesized compounds were tested for cytotoxic activity and among these compounds 4b and 5a shows prominent cytotoxic activity against triple-negative breast cancer (TNBC) cells MDA-MB-231 with IC50 values 47.72 μM and 24.25 μM, respectively. Distinguishing morphological changes were noticed in MDA-MB-231 cells treated with pyrazole hybrids contributing to apoptosis action. To get more insight into cytotoxic activity, in silico molecular docking of these compounds were performed and the results suggested that (E)-3-(1-benzyl-3,5-dimethyl-1H-pyrazol-4-yl)-1-(p-tolyl)prop-2-en-1-one and 1-(1'-benzyl-5-(4-chlorophenyl)-3',5'-dimethyl-3,4-dihydro-1'H,2H-[3,4'-bipyrazol]-2-yl)ethan-1-one binds to the prominent domain of Akt2 indicating their potential ability as Akt2 inhibitor. Moreover, from in silico ADME studies clearly demonstrated that these compounds may be regarded as a drug candidate for sub-lingual absorption based on log p values (2.157-4.924). These compounds also show promising antitubercular activity. The overall results suggest that pyrazolic hybrids with substitution at less sterically hindered positions have appealing potent cytotoxic activity and antituberculosis activity due to which they may act as multidrug candidate.

Synthesis and clinical application of small-molecule inhibitors and PROTACs of anaplastic lymphoma kinase

Pharmacological interventions that specifically target protein products of oncogenes in tumors have surfaced as a propitious therapeutic approach. Among infrequent genetic alterations, rearrangements of the anaplastic lymphoma kinase (ALK) gene, typically involving a chromosome 2 inversion that culminates in a fusion with the echinoderm microtubule-associated protein like 4 (EML4), lead to anomalous expression and activation of ALK. The inhibition of autophosphorylation and subsequent blockade of signal transduction by ALK tyrosine kinase inhibitors (TKIs) has been observed to elicit anti-tumor effects. Currently, four generations of ALK-positive targeted drugs have been investigated, providing a promising outlook for patients. The aim of this review is to furnish a comprehensive survey of the synthesis and clinical application of prototypical small-molecule ALK inhibitors in both preclinical and clinical phases, offering guidance for further development of ALK inhibitors for cancer therapy.

Design, synthesis, and docking studies of novel pyrazole-based scaffolds and their evaluation as VEGFR2 inhibitors in the treatment of prostate cancer

Since VEGFR-2 plays a crucial role in tumor growth, angiogenesis, and metastasis, it is a prospective target for cancer treatment. In this work, a series of 3-phenyl-4-(2-substituted phenylhydrazono)-1H-pyrazol-5(4H)-ones (3a-l) were synthesized and investigated for their cytotoxicity against the PC-3 human cancer cell line compared to Doxorubicin and Sorafenib as reference drugs. Two compounds 3a and 3i showed comparable cytotoxic activity with IC₅₀ values of 1.22 and 1.24 μM compared to the reference drugs (IC₅₀ = 0.932, 1.13 μM). Compound 3i was found to be the most effective VEGFR-2 inhibitor using in vitro testing of the synthesized compounds, with nearly 3-fold higher activity than Sorafenib (30 nM), with IC₅₀ 8.93 nM. Compound 3i significantly stimulated total apoptotic prostate cancer cell death 55.2-fold (34.26% compared to 0.62% for the control) arresting the cell cycle at the S-phase. The genes involved in apoptosis were also impacted, with proapoptotic genes being upregulated and antiapoptotic Bcl-2 being downregulated. These results were supported by docking studies of these two compounds within the active site of the VEGFR2 enzyme. Finally, in vivo, the study revealed the potentiality of compound 3i to inhibit tumor proliferation by 49.8% reducing the tumor weight from 234.6 mg in untreated mice to 83.2 mg. Therefore, 3i could be a promising anti-prostate cancer agent.

Fragment-based discovery of novel phenyltriazolyl derivatives as allosteric type-I1/2 ALK inhibitors with promising antitumor effects

Based on the high-throughput screening hit BY-1, a series of phenyltriazolyl derivatives were developed. Satisfyingly, most compounds were detected moderate to excellent antitumor effects against Karpas299 and H2228 cells. Among them, 12k bearing 4‑hydroxypiperidinyl group exhibited the optimal activities against tested cells with IC₅₀ values of 51 nM and 175 nM, as well as promising inhibitory effects on ALK^WT (3.7 nM) and ALK^L1196M (6.8 nM). Unlike the conventional type-I ALK inhibitors, molecular models identified 12k as an allosteric type-I^1/2 inhibitor by forming key interactions in both the ATP binding region and the hydrophobic back pocket of ALK. Intriguingly, 12k could dose-dependently induce apoptosis on H2228 cell and inhibit colony formation and tumor cell migration. Taken together, the rationalization of 12k may shed new light on the identification of novel allosteric type-I^1/2 ALK inhibitors.

Development and investigation of thiazolidinedione and pyrazoline compounds as antiangiogenic weapons targeting VEGFR-2

Background: Angiogenesis deregulation is often linked to cancer and is thus an essential target. Materials & methods: Twenty-nine compounds were developed as VEGFR-2 inhibitors. Compounds were evaluated to determine their antiangiogenic activity. Results: B1, PB11 and PB16 showed HUVEC's IC₅₀ scores in the submicromolar range. B1, B2 and PB16 reduced cellular migration and capillary tube formation of HUVECs. VEGFR-2 inhibitory activity was found in the nanomolar range: 200 nM of B1, 500 nM of B2 and 600 nM of PB16. B1 and PB16 suppressed the formation of new capillaries on growing CAMs. B1 and PB16 occupied the ATP site and allosteric pocket of VEGFR-2 in docking studies. Conclusion: These compounds can target VEGFR-2 and are endowed with in vitro and in vivo antiangiogenic activity.

Therapeutic Targeting of the Anaplastic Lymphoma Kinase (ALK) in Neuroblastoma-A Comprehensive Update

Neuroblastoma (NBL) is an embryonic malignancy of the sympathetic nervous system and mostly affects children under the age of five. NBL is highly heterogeneous and ranges from spontaneously regressing to highly aggressive disease. One of the risk factors for poor prognosis are aberrations in the receptor tyrosine kinase anaplastic lymphoma kinase (ALK), which is involved in the normal development and function of the nervous system. ALK mutations lead to constitutive activation of ALK and its downstream signalling pathways, thus driving tumorigenesis. A wide range of steric ALK inhibitors has been synthesized, and several of these inhibitors are already in clinical use. Major challenges are acquired drug resistance to steric inhibitors and pathway evasion strategies of cancer cells upon targeted therapy. This review will give a comprehensive overview on ALK inhibitors in clinical use in high-risk NBL and on the potential and limitations of novel inhibitors. Because combinatory treatment regimens are probably less likely to induce drug resistance, a special focus will be on the combination of ALK inhibitors with drugs that either target downstream signalling pathways or that affect the survival and proliferation of cancer cells in general.

Novel targeted therapies of T cell lymphomas

T cell lymphomas (TCL) comprise a heterogeneous group of non-Hodgkin lymphomas (NHL) that often present at an advanced stage at the time of diagnosis and that most commonly have an aggressive clinical course. Treatment in the front-line setting is most often cyclophosphamide, doxorubicin, vincristine, and prednisone (CHOP) or CHOP-like regimens, which are effective in B cell lymphomas, but in TCL are associated with a high failure rate and frequent relapses. Furthermore, in contrast to B cell NHL, in which substantial clinical progress has been made with the introduction of monoclonal antibodies, no comparable advances have been seen in TCL. To change this situation and improve the prognosis in TCL, new gene-targeted therapies must be developed. This is now possible due to enormous progress that has been made in the last years in the understanding of the biology and molecular pathogenesis of TCL, which enables the implementation of the research findings in clinical practice. In this review, we present new therapies and current clinical and preclinical trials on targeted treatments for TCL using histone deacetylase inhibitors (HDACi), antibodies, chimeric antigen receptor T cells (CARTs), phosphatidylinositol 3-kinase inhibitors (PI3Ki), anaplastic lymphoma kinase inhibitors (ALKi), and antibiotics, used alone or in combinations. The recent clinical success of ALKi and conjugated anti-CD30 antibody (brentuximab-vedotin) suggests that novel therapies for TCL can significantly improve outcomes when properly targeted.

Novel piperazine-chalcone hybrids and related pyrazoline analogues targeting VEGFR-2 kinase; design, synthesis, molecular docking studies, and anticancer evaluation

New piperazine–chalcone hybrids and related pyrazoline derivatives have been designed and synthesised as potential vascular endothelial growth factor receptor-2 (VEGFR-2) inhibitors. The National Cancer Institute (NCI) has selected six compounds to evaluate their antiproliferative activity in vitro against 60 human cancer cells lines. Preliminary screening of the examined compounds indicated promising anticancer activity against number of cell lines. The enzyme inhibitory activity against VEGFR-2 was evaluated and IC₅₀ of the tested compounds ranged from 0.57 µM to 1.48 µM. The most potent derivatives Vd and Ve were subjected to further investigations. A cell cycle analysis showed that both compounds mainly arrest HCT-116 cell cycle in the G2/M phase. Annexin V-FITC apoptosis assay showed that Vd and Ve induced an approximately 18.7-fold and 21.2-fold total increase in apoptosis compared to the control. Additionally, molecular docking study was performed against VEGFR (PDB ID: 4ASD) using MOE 2015.10 software and Sorafenib as a reference ligand.

Overview of recent developments of pyrazole derivatives as an anticancer agent in different cell line

Pyrazole is a five-membered aromatic heterocyclic ring with two adjacent nitrogen atoms C₃H₃N₂H.The presence of this nucleus in pharmacological agents of various therapeutic categories gifts a broad spectrum of biological activities and pharmaceuticals that contain pyrazole like celecoxib (anti-inflammatory), CDPPB (antipsychotic), Rimonabant (anti-obesity), Difenamizole, (Analgesic), Betazole (H2 receptor agonist), Fezolamide (Antidepressant), etc… The pharmacological potential of the pyrazole fraction is proved in many publication where they synthesized and evaluated pyrazoles against several biological agents. The aim of this article review is to survey recent works linking pyrazole structures to anticancer activities corresponding to 9 different type of cancer.

Synthesis and anti-tumor efficacy of novel 2, 4-diarylaminopyrimidine derivatives bearing N-(3-pyridinylmethyl) urea moiety as anaplastic lymphoma kinase inhibitors

Anaplastic lymphoma kinase (ALK) is a receptor tyrosine kinase responsible for development of various tumor types. In this study, we synthesized a series of novel 2,4-diarylaminopyrimidine derivatives possessing a unique N-(3-pyridinylmethyl)urea moiety as ALK inhibitors. The most promising analog 5m bearing a 3-methoxy-4-morpholinophenyl substituent significantly inhibited proliferation of ALK positive H3122 and Karpas-299 cells with IC₅₀ values about 10 nM, which were comparable with positive control LDK378. Compound 5m suppressed phosphorylation of ALK and its downstream proteins, and showed low cytotoxicity on normal human primary fibroblast cells (BJ cells). The binding mode of 5m was proposed by docking simulation, which explains the important role of N-(3-pyridinylmethyl)urea moiety. Furthermore, compound 5m exhibited favorable liver microsomal stability and significant efficacy in H3122 xenograft mice model. Interestingly, compound 5m also showed broader anti-proliferative activity on other human tumor cell lines, which was different from other ALK inhibitors.

Drug Discovery Targeting Anaplastic Lymphoma Kinase (ALK)

As a receptor tyrosine kinase of insulin receptor (IR) subfamily, anaplastic lymphoma kinase (ALK) has been validated to play important roles in various cancers, especially anaplastic large cell lymphoma (ALCL), nonsmall cell lung cancer (NSCLC), and neuroblastomas. Currently, five small-molecule inhibitors of ALK, including Crizotinib, Ceritinib, Alectinib, Brigatinib, and Lorlatinib, have been approved by the U.S. Food and Drug Administration (FDA) against ALK-positive NSCLCs. Novel type-I¹/₂ and type-II ALK inhibitors with improved kinase selectivity and enhanced capability to combat drug resistance have also been reported. Moreover, the "proteolysis targeting chimera" (PROTAC) technique has been successfully applied in developing ALK degraders, which opened a new avenue for targeted ALK therapies. This review provides an overview of the physiological and biological functions of ALK, the discovery and development of drugs targeting ALK by focusing on their chemotypes, activity, selectivity, and resistance as well as potential therapeutic strategies to overcome drug resistance.

Synthesis of pyrazolylvinyl ketones from furan derivatives

A new protocol for the synthesis of pyrazol-5-ylvinyl ketones, e.g. pyrazole-chalcones, employing furfuryl ketones as a triketone equivalent, has been described.

Importance of protein flexibility in molecular recognition: a case study on Type-I1/2 inhibitors of ALK

Anaplastic lymphoma kinase (ALK) has been regarded as a promising target for the therapy of various cancers.

Combating Drug-Resistant Mutants of Anaplastic Lymphoma Kinase with Potent and Selective Type-I1/2 Inhibitors by Stabilizing Unique DFG-Shifted Loop Conformation

Targeted inhibition of anaplastic lymphoma kinase (ALK) dramatically improved therapeutic outcomes in the treatment of ALK-positive cancers, but unfortunately patients invariably progressed due to acquired resistance mutations in ALK. Currently available drugs are all type-I inhibitors bound to the ATP-binding pocket and are most likely to be resistant in patients harboring genetic mutations surrounding the ATP pocket. To overcome drug resistance, we rationally designed a novel kind of "bridge" inhibitor, which specially bind into an extended hydrophobic back pocket adjacent to the ATP-binding site of ALK. The novel type-I^1/2 inhibitors display excellent antiproliferation activity against ALK-positive cancer cells and appear superior to two clinically used drugs, crizotinib and ceritinib. Structural and molecular modeling analyses indicate that the inhibitor induces dramatic conformational transition and stabilizes unique DFG-shifted loop conformation, enabling persistent sensitivity to different genetic mutations in ALK. These data highlight a rationale for further development of next-generation ALK inhibitors to combat drug resistance.

Mutation L1196M-induced conformational changes and the drug resistant mechanism of anaplastic lymphoma kinase studied by free energy perturbation and umbrella sampling

Anaplastic lymphoma kinase (ALK) has been regarded as a promising drug target in the treatment of tumors and the mutation L1196M induces different levels of drug resistance toward the existing inhibitors.