New antiproliferative 7-(4-(N-substituted carbamoylmethyl)piperazin-1-yl) derivatives of ciprofloxacin induce cell cycle arrest at G2/M phase

New N-4-piperazinyl derivatives of ciprofloxacin 2a–g were prepared and tested for their cytotoxic activity. The primary in vitro one dose anticancer assay experienced promising cytotoxic activity against different cancer cell lines especially non-small cell lung cancer. Independently, compounds 2b, 2d, 2f and 2g showed anticancer activity against human non-small cell lung cancer A549 cells (IC₅₀ = 14.8, 24.8, 23.6 and 20.7 μM, respectively) compared to the parent ciprofloxacin (IC₅₀ >100 μM) and doxorubicin as a positive control (IC₅₀ = 1 μM). The flow cytometric analysis for 2b showed dose dependent G₂/M arrest in A549 cells. Also, 2b increased the expression of p53 and p21 and decreased the expression of cyclin B1 and Cdc2 proteins in A549 cells without any effect on the same proteins expression in WI-38 cells. Specific inhibition of p53 by pifithrin-α reversed the G₂/M phase arrest induced by the 2b compound, suggesting contribution of p53 to increase. Taken together, 2b induced G₂/M phase arrest via p53/p21 dependent pathway. The results indicate that 2b can be used as a lead compound for further development of new derivatives against non-small cell lung cancer.     

Design and synthesis of a series of bioavailable fatty acid synthase (FASN) KR domain inhibitors for cancer therapy

We designed and synthesized a new series of fatty acid synthase (FASN) inhibitors with potential utility for the treatment of cancer. Extensive SAR studies led to highly active FASN inhibitors with good cellular activity and oral bioavailability, exemplified by compound 34. Compound 34 is a potent inhibitor of human FASN (IC₅₀?=?28?nM) that effectively inhibits proliferation of A2780 ovarian cells (IC₅₀?=?13?nM) in lipid-reduced serum (LRS). This cellular activity can be rescued by addition of palmitate, consistent with an on-target effect. Compound 34 is also active in many other cell types, including PC3M (IC₅₀?=?25?nM) and LnCaP-Vancouver prostate cells (IC₅₀?=?66?nM), and is highly bioavailable (F 61%) with good exposure after oral administration. In a pharmacodynamics study in H460 lung xenograft-bearing mice, oral treatment with compound 34 results in elevated tumor levels of malonyl-CoA and decreased tumor levels of palmitate, fully consistent with the desired target engagement.     

4,6-Substituted-1H-Indazoles as potent IDO1/TDO dual inhibitors

Indoleamine 2,3-dioxygenase 1 (IDO1) and tryptophan 2,3-dioxygenase (TDO) are constitutively overexpressed in many types of cancer cells and exert important immunosuppressive functions. In this article, a series of 4,6-substituted-1H-indazole derivatives were synthesized and evaluated the inhibitory activities against IDO1 and TDO, as well as their structure-activity relationships (SARs). Among these, compound 35 displayed the most IDO1 inhibitory potency with an IC₅₀ value of 0.74?μM in an enzymatic assay and 1.37?μM in HeLa cells. Quantitative analysis of the Western blot results indicated that 35 significantly decreased the INFγ-induced IDO1 expression in a concentration-dependent manner. In addition, 35 showed promising TDO inhibition with an IC₅₀ value of 2.93?μM in the enzymatic assay and 7.54?μM in A172 cells. Moreover, compound 35 exhibited in vivo antitumor activity in the CT26 xenograft model. These findings suggest that 1H-indazole derivative 35 is a potent IDO1/TDO dual inhibitor, and has the potential to be developed for IDO1/TDO-related cancer treatment.     

Design,synthesis, in vitro and in vivo evaluation,and structure-activity relationship (SAR) discussion of novel dipeptidyl boronic acid proteasome inhibitors as orally available anti-cancer agents for the treatment of multiple myeloma and mechanism studies

A series of novel dipeptidyl boronic acid inhibitors of 20S proteasome were designed and synthesized. Aliphatic groups at R¹ position were designed for the first time to fully understand the SAR (structure–activity relationship). Among the screened compounds, novel inhibitor 5c inhibited the CT-L (chymotrypsin-like) activity with IC₅₀ of 8.21?nM and the MM (multiple myeloma) cells RPMI8226, U266B and ARH77 proliferations with the IC₅₀ of 8.99, 6.75 and 9.10?nM, respectively, which showed similar in vitro activities compared with the compound MLN2238 (biologically active form of marketed MLN9708). To investigate the oral availability, compound 5c was esterified to its prodrug 6a with the enzymatic IC₅₀ of 6.74?nM and RPMI8226, U266B and ARH77 cell proliferations IC₅₀ of 2.59, 4.32 and 3.68?nM, respectively. Furthermore, prodrug 6a exhibited good pharmacokinetic properties with oral bioavailability of 24.9%, similar with MLN9708 (27.8%). Moreover, compound 6a showed good microsomal stabilities and displayed stronger in vivo anticancer efficacy than MLN9708 in the human ARH77 xenograft mouse model. Finally, cell cycle results showed that compound 6a had a significant inhibitory effect on CT-L and inhibited cell cycle progression at the G2M stage.     

Novel quinazoline derivatives bearing various 6-benzamide moieties as highly selective and potent EGFR inhibitors

A series of novel quinazoline derivatives bearing various C-6 benzamide substituents were synthesized and evaluated as EGFR inhibitors, and most showed significant inhibitory potency against EGFR kinase. In particular, compound 6g possessed potent inhibitory activity against EGFR wild-type (IC₅₀?=?5?nM), and strong antiproliferative activity against HCC827 and Ba/F3 (L858R) cell lines. Kinase profiling against a panel of 365 kinases showed that 6g was highly selective for EGFR. Furthermore, 6g showed desirable properties in assays of liver microsome metabolic stability and cytochromes P450 inhibition and preliminary pharmacokinetic study. The overall attractive profile of 6g made it an interesting compound for further development.     

Design,synthesis and biological evaluation of novel pyrazolo-oxothiazolidine derivatives as antiproliferative agents against human lung cancer cell line A549

An efficient, one-pot multicomponent reaction of novel pyrazolo-oxothiazolidine derivatives was achieved by condensation of 1-(benzofuran-2-yl)-3-(substituted-arylprop-2-en-1-ones, thiosemicarbazide and dialkyl acetylenedicarboxylates under the optimized reaction conditions. Synthesised compounds were evaluated for their antiproliferative activity against A549 human lung cancer cell line. Among all the tested compounds, 4a (IC₅₀ – 0.930?μg/mL), 4e (IC₅₀ – 1.207?μg/mL), 4f (IC₅₀ – 0.808?μg/mL), 4g (IC₅₀ – 1.078?μg/mL), 4h (IC₅₀ – 0.967?μg/mL) and 4j (IC₅₀ – 2.445?μg/mL) showed promising activity compared with standard drug Sorafenib (IC₅₀ – 3.779?μg/mL). Molecular docking studies indicated that compound 4f had the greatest affinity for catalytic site of receptors EGFR (PDB ID code: 1?M17) and VEGFR2 (PDB ID code: 4AGD, 4ASD). These novel pyrazolo-oxothiazolidine derivatives can be promising therapeutic agents for A549 human lung cancer cell line.     

Synthesis and SAR of novel capsazepine analogs with significant anti-cancer effects in multiple cancer types

We previously demonstrated that capsazepine (CPZ), a synthetic transient receptor potential Vanilloid subtype 1 (TRPV1) antagonist, has significant anti-cancer effects in vivo. The purpose of this study was to develop more potent analogs based upon CPZ pharmacophore and structure–activity relationships (SAR) across analogs. We generated 30 novel compounds and screened for their anti-proliferative effects in cultured HeLa cervical cancer cells. Cell viability assays identified multiple compounds with IC_50s?<?15?μM and one compound, 29 with an IC₅₀?<?5?μM; six fold more potent than CPZ. We validated the anti-proliferative efficacy of two lead compounds, 17 and 29, in vivo using HeLa-derived xenografts in athymic nude mice. Both analogs significantly reduced tumor volumes by day 8 compared to control treated animals (p?<?0.001) with no observable adverse effects. Calcium imaging determined that compound 17 activates TRPV1 whereas 29 neither activates nor inhibits TRPV1; indicating a unique mechanism-of-action that does not involve TRPV1 signaling. Cell viability assays using a panel of additional tumor types including oral squamous cell carcinoma, non-small cell lung cancer (NSCLC), breast cancer, and prostate cancer cell lines (HSC-3, H460, MDA-231, and PC-3 respectively) demonstrated that both lead compounds were efficacious against every cancer type tested. Compounds 29 displayed IC_50s of 1–2.5?μM in HSC-3and PC-3cells. Thus, we propose that these novel CPZ analogs may serve as efficacious therapeutic agents against multiple tumor types that warrant further development for clinical application.     

Discovery of N-aryl-N′-pyrimidin-4-yl ureas as irreversible L858R/T790M mutant selective epidermal growth factor receptor inhibitors

A novel series of N-aryl-N′-pyrimidin-4-yl ureas has been optimized to afford potent and selective inhibitors of the EGFR L858R/T790M. The most representative compound 28 showed high activity against EGFR L858R/T790M kinase (IC₅₀?=?4?nM) and 22-fold selectivity against wild type EGFR. Moreover, compound 28 potently inhibited EGFR L858R/T790M phosphorylation (IC₅₀?=?41?nM) and cellular proliferation (IC₅₀?=?37?nM) in the H1975 cell line, while being significantly less toxic to A431 cells. Further, compound 28 exhibited a great selectivity in a mini-panel of kinases.     

Synthesis and bioevaluation study of novel N-methylpicolinamide and thienopyrimidine derivatives as selectivity c-Met kinase inhibitors

Four series of N-methylpicolinamide moiety and thienopyrimidine moiety bearing pyridazinone were designed and synthesized and evaluated for the IC₅₀ values against three cancer cell lines (A549, HepG2 and MCF-7) and some selected compounds were further evaluated for the activity against c-Met, Flt-3, VEGFR-2, c-Kit and EGFR kinases. Three compounds (35, 39 and 43) showed more active than positive control Foretinib against A549, HepG2 and MCF-7 cell lines. The most promising compound 43 showed superior activity against A549, HepG2 and MCF-7, with the IC₅₀ values of 0.58?±?0.15?µM, 0.47?±?0.06?µM and 0.74?±?0.12?µM, which were 3.73–5.39-fold more activity than Foretinib, respectively. The experiments of enzyme-based showed that 43 restrain the c-Met selectively, with the IC₅₀ values of 16?nM, which showed equal activity to Foretinib (14?nM) and better than the compound 5 (90?nM). Moreover, AO and Annexin V/PI staining and docking studies were carried out.     

Design,synthesis, and bioactivity of dihydropyrimidine derivatives as kinesin spindle protein inhibitors

A series of twenty-one 3,4-dihydropyrimidine derivatives bearing the heterocyclic 1,3-benzodioxole at position 4 in addition to different substituents at positions 2, 3 and 5 were designed and synthesized as monastrol analogs. The novel synthesized compounds were screened for their cytotoxic activity towards 60 cancer cell lines according to NCI (USA) protocol. Compounds 10b and 15 showed the best antitumor activity against most cell lines. Compound 15 was subsequently tested in 5-doses mode and displayed high selectivity towards CNS, prostate and leukemia subpanel with selectivity ratios of 22.30, 15.38 and 12.56, respectively at GI₅₀ level. The IC₅₀ of compounds 9d, 10b, 12, 15 and 16 against kinesin enzyme were 3.86 ± 0.12, 10.70 ± 0.35, 3.95 ± 0.12, 4.36 ± 0.14, and 14.07 ± 0.45 μM respectively, while the prototype compound, monastrol, reported IC₅₀ value of 20 ± 0.42 μM. The safest compound among test compounds against normal cell line (HEK 293) is 10b with IC₅₀ value of 62.02 ± 2.42 µM/ml in comparison to doxorubicin (IC₅₀ = 11.34 ± 0.44 µM/ml). Cell cycle analysis of SNB-75 cells treated with compound 15 showed cell cycle arrest at G2/M phase. Further, the assay of levels of active caspase-3 and caspase-9 was investigated. Moreover, Molecular docking of compounds, 9d, 10b, 12, 15, 16, monastrol and mon-97 was performed to study the interaction between inhibitors and the kinesin spindle protein allosteric binding site.     

Structure-based optimization and biological evaluation of trisubstituted pyrazole as a core structure of potent ROS1 kinase inhibitors

Recently inhibition of ROS1 kinase has proven to be a promising strategy for several indications such as glioblastoma, non-small cell lung cancer (NSCLC), and cholangiocarcinoma. Our team reported trisubstituted pyrazole-based ROS1 inhibitors by which two inhibitors showed good IC₅₀ values in enzyme-based screening. To develop more advanced ROS1 inhibitors through SAR this trisubstituted pyrazole-based scaffold has been built. Consequently, 16 compounds have been designed, synthesized and shown potent IC₅₀ values in the enzymatic assay, which are from 13.6 to 283 nM. Molecular modeling studies explain how these ROS1 kinase inhibitors revealed effectively the key interactions with ROS1 ATP binding site. Among these compounds, compound 9a (IC₅₀ = 13.6 nM) has exerted 5 fold potency than crizotinib and exhibited high degree of selectivity (selectivity score value = 0.028) representing the number of non-mutant kinases with biological activity over 90% at 10 μM.     

Structure-based design and synthesis of 1H-pyrazolo[3,4-d]pyrimidin-4-amino derivatives as Janus kinase 3 inhibitors

Janus kinases (JAKs) regulate various inflammatory and immune responses and are targets for the treatment of inflammatory and immune diseases. Here we report the discovery and optimization of 1H-pyrazolo[3,4-d]pyrimidin-4-amino as covalent JAK3 inhibitors that exploit a unique cysteine (Cys909) residue in JAK3. Our optimization study gave compound 12a, which exhibited potent JAK3 inhibitory activity (IC₅₀ of 6.2?nM) as well as excellent JAK kinase selectivity (>60-fold). In cellular assay, 12a exhibited potent immunomodulating effect on IL-2-stimulated T cell proliferation (IC₅₀ of 9.4?μM). Further, compound 12a showed efficacy in delayed hypersensitivity assay. The data supports the further investigation of these compounds as novel JAKs inhibitors.     

Synthesis,biological evaluation and molecular docking of benzimidazole grafted benzsulfamide-containing pyrazole ring derivatives as novel tubulin polymerization inhibitors

Tubulin-targeting drugs have increasingly become the focus of anticancer drugs research. Twenty-five novel benzimidazole grafted benzsulfamide-containing pyrazole ring derivatives were synthesized and evaluated for bioactivity as potential tubulin polymerization inhibitors. Among them, compound 30 showed the most excellent inhibition against tubulin assembly (IC₅₀?=?1.52?μM) and in vitro growth inhibitory activity against a panel of four human cancer cell lines (IC₅₀?=?0.15, 0.21, 0.33 and 0.17?μM, respectively for A549, Hela, HepG2 and MCF-7). It could also validly induce A549 cell apoptosis, cause cell cycle arrest in G2/M phase and disrupt the cellular microtubule network. These results, along with molecular docking data, provided an important basis for further optimization of compound 30 as a potential anticancer agent.     

Sulfamic acid promoted one-pot synthesis of phenanthrene fused-dihydrodibenzo-quinolinones: Anticancer activity,tubulin polymerization inhibition and apoptosis inducing studies

A facile one-pot method for the synthesis of new phenanthrene fused-dihydrodibenzo-quinolinone derivatives has been successfully accomplished by employing sulfamic acid as catalyst. These new compounds were evaluated for their in vitro cytotoxic potential against human lung (A549), prostate (PC-3 and DU145), breast (MCF-7) and colon (HT-29 and HCT-116) cancer cell lines. Among all the tested compounds, one of the derivatives 8p showed good anti-proliferative activity against A549 lung cancer cell line with an IC₅₀ of 3.17?±?0.52?µM. Flow cytometric analyses revealed that compound 8p arrested both Sub G1 and G2/M phases of cell cycle in a dose dependent manner. The compound 8p also displayed significant inhibition of tubulin polymerization and disruption of microtubule network (IC₅₀ of 5.15?±?0.15?µM). Molecular docking studies revealed that compound 8p efficiently interacted with critical amino acid Cys241 of the α/β-tubulin by a hydrogen bond (SH…O?=?2.4?Å). Further, the effect of 8p on cell viability was also studied by AO/EB, DCFDA and DAPI staining. The apoptotic characteristic features revealed that 8p inhibited cell proliferation effectively through apoptosis by inducing the ROS generation. Analysis of mitochondrial membrane potential through JC-1 staining and annexin V binding assay indicated the extent of apoptosis in A549 cancer cells.     

Design,synthesis, and biological evaluation of novel aminopyrimidinylisoindolines as AXL kinase inhibitors

A novel series of aminopyrimidinylisoindoline derivatives 1a-w having an aminopyrimidine scaffold as a hinge region binding motif were designed and synthesized. Among them, six compounds showed potent inhibitory activities against AXL kinase with IC₅₀ values of submicromolar range. Especially, compound 1u possessing (4-acetylpiperazin-1-yl)phenyl moiety exhibited extremely excellent efficacy (IC₅₀?=?<0.00050?μM). Their in vitro antiproliferative activities were tested over five cancer cell lines. Most compounds showed good antiproliferative activities against HeLa cell line. The kinase panel profiling of 50 different kinases and the selected inhibitory activities for the representative compound 1u were carried out. The compound 1u exhibited excellent inhibitory activities (IC₅₀?=?<0.00050, 0.025, and 0.050?μM for AXL, MER, and TYRO3, respectively) against TAM family, together with potent antiproliferative activity against MV4-11 cell line (GI₅₀?=?0.10?μM) related to acute myeloid leukemia (AML).     

Design,synthesis and molecular modeling of new 4-phenylcoumarin derivatives as tubulin polymerization inhibitors targeting MCF-7 breast cancer cells

A new set of 4-phenylcoumarin derivatives was designed and synthesized aiming to introduce new tubulin polymerization inhibitors as anti-breast cancer candidates. All the target compounds were evaluated for their cytotoxic effects against MCF-7 cell line, where compounds 2f, 3a, 3b, 3f, 7a and 7b, showed higher cytotoxic effect (IC₅₀?=?4.3–21.2?μg/mL) than the reference drug doxorubicin (IC₅₀?=?26.1?μg/mL), additionally, compounds 1 and 6b exhibited the same potency as doxorubicin (IC₅₀?=?25.2 and 28.0?μg/mL, respectively). The thiazolidinone derivatives 3a, 3b and 3f with potent and selective anticancer effects towards MCF-7 cells (IC₅₀?=?11.1, 16.7 and 21.2?μg/mL) were further assessed for tubulin polymerization inhibition effects which showed that the three compounds were potent tubulin polymerization suppressors with IC₅₀ values of 9.37, 2.89 and 6.13?μM, respectively, compared to the reference drug colchicine (IC₅₀?=?6.93?μM). The mechanistic effects on cell cycle progression and induction of apoptosis in MCF-7 cells were determined for compound 3a due to its potent and selective cytotoxic effects in addition to its promising tubulin polymerization inhibition potency. The results revealed that compound 3a induced cell cycle cessation at G2/M phase and accumulation of cells in pre-G1 phase and prevented its mitotic cycle, in addition to its activation of caspase-7 mediating apoptosis of MCF-7 cells. Molecular modeling studies for compounds 3a, 3b and 3f were carried out on tubulin crystallography, the results indicated that the compounds showed binding mode similar to the co-crystalized ligand; colchicine. Moreover, pharmacophore constructed models and docking studies revealed that thiazolidinone, acetamide and coumarin moieties are crucial for the activity. Molecular dynamics (MD) studies were carried out for the three compounds over 100?ps. MD results of compound 3a showed that it reached the stable state after 30?ps which was in agreement with the calculated potential and kinetic energy of compound 3a.     

(E)-N-Aryl-2-oxo-2-(3,4,5-trimethoxyphenyl)acetohydrazonoyl cyanides as tubulin polymerization inhibitors: Structure-based bioisosterism design,synthesis, biological evaluation,molecular docking and in silico ADME prediction

A series of (E)-N-Aryl-2-oxo-2-(3,4,5-trimethoxyphenyl)acetohydrazonoyl cyanides have been synthesized and evaluated for their anticancer activity in human hepatocellular liver carcinoma HepG2 and breast adenocarcinoma MCF-7?cell lines. Among all the tested compounds, compound 3a, 3e and 3n displayed more activity than lead compound with IC₅₀ value of 0.26–0.61?μM. Meanwhile, these compounds (3a, 3e and 3n) showed potent antiproliferative activity against a panel of cancer cells and the HCT-8/T multidrug resistant cell line with IC₅₀ values in the range of 0.077– 7.44?μM. Flow cytometric analyses revealed that compound 3n induced cell cycle arrest in G2/M phases in a dose dependent manner. The compound 3n also displayed potent tubulin polymerization inhibition with an IC₅₀ value of 0.9?µM, with ten folds more active than colchicine (IC₅₀?=?9?μM). Molecular docking studies revealed that compound 3n efficiently interacted with the colchicine binding site of tubulin through hydrophobic, cation-π and hydrogen bond interaction. Furthermore, in silico pharmacokinetic prediction shown that these compounds have a good ADME-related physicochemical parameters. These results demonstrate that 3n exhibits potent cytotoxicity in cancer cells by targeting the colchicine binding site of tubulin and potentially acts as a therapeutic lead compound for the development of anticancer drugs.     

Discovery and optimization of a series of small-molecule allosteric inhibitors of MALT1 protease

We describe a series of potent and highly selective small-molecule MALT1 inhibitors, optimized from a High-Throughput Screening hit. Advanced analogues such as compound 40 show high potency (IC₅₀: 0.01 µM) in a biochemical assay measuring MALT1 enzymatic activity, as well as in cellular assays: Jurkat T cell activation (0.05 µM) and IL6/10 secretion (IC₅₀: 0.10/0.06 µM) in the TMD8 B-cell lymphoma line. Compound 40 also inhibited cleavage of the MALT1 substrate RelB (IC₅₀: 0.10 µM). Mechanistic enzymology results suggest that these compounds bind to the known allosteric site of the protease.     

Design,synthesis and in vitro evaluation of stilbene derivatives as novel LSD1 inhibitors for AML therapy

LSD1 is implicated in a number of malignancies and has emerged as an exciting target. As part of our sustained efforts to develop novel reversible LSD1 inhibitors for epigenetic therapy of cancers, in this study, we reported a series of stilbene derivatives and evaluated their LSD1 inhibitory activities, obtaining several compounds as potent LSD1 inhibitors with IC₅₀ values in submicromolar range. Enzyme kinetics studies and SPR assay suggested that compound 8c, the most active LSD1 inhibitor (IC₅₀?=?283?nM), potently inhibited LSD1 in a reversible and FAD competitive manner. Consistent with the kinetics data, molecular docking showed that compound 8c can be well docked into the FAD binding site of LSD1. Flow cytometry analysis showed that compound 8c was capable of up-regulating the expression of the surrogate cellular biomarker CD86 in THP-1 human leukemia cells, suggesting the ability to block LSD1 activity in cells. Compound 8c showed good inhibition against THP-1 and MOLM-13 cells with IC₅₀ values of 5.76 and 8.34?μM, respectively. Moreover, compound 8c significantly inhibited colony formation of THP-1 cells dose dependently.     

Discovery of thiazolidin-4-one urea analogues as novel multikinase inhibitors that potently inhibit FLT3 and VEGFR2

A series of novel thiazolidine-4-one urea analogues were designed, synthesized and biologically evaluated. The structure-activity relationship (SAR) at several positions of the scaffolds was investigated and its binding mode was analyzed by molecular modeling studies. Compound 17b proved to be the most potent one, and IC₅₀ values against A549 and HT-29 cancer cell lines were 0.65?μM and 0.11?μM, respectively. The results of kinase profile demonstrated that compound 17b is a multikinase inhibitor that potently inhibits FLT3 (IC₅₀?=?8.6?nM) and VEGFR2 (IC₅₀?=?18.7?nM). The results of real-time live-cell imaging indicated that compound 17b showed excellent cytotoxicity and anti-proliferative activity against HT-29 cancer cells in a time- and dose-dependent manner, which was significantly potent than that of Cabozantinib. In addition, in vitro antitumor activity was associated with inducing cancer cell apoptosis and suppression of cancer cell migration.