Discovery of New Imidazo[2,1-b]thiazole Derivatives as Potent Pan-RAF Inhibitors with Promising In Vitro and In Vivo Anti-melanoma Activity.

BRAF is an important component of MAPK cascade. Mutation of BRAF, in particular V600E, leads to hyperactivation of the MAPK pathway and uncontrolled cellular growth. Resistance to selective inhibitors of mutated BRAF is a major obstacle against treatment of many cancer types. In this work, a series of new (imidazo[2,1-b]thiazol-5-yl)pyrimidine derivatives possessing a terminal sulfonamide moiety were synthesized. Pan-RAF inhibitory effect of the new series was investigated, and structure-activity relationship is discussed. Antiproliferative activity of the target compounds was tested against the NCI-60 cell line panel. The most active compounds were further tested to obtain their IC50 values against cancer cells. Compound 27c with terminal open chain sulfonamide and 38a with a cyclic sulfamide moiety showed the highest activity in enzymatic and cellular assay, and both compounds were able to inhibit phosphorylation of MEK and ERK. Compound 38a was selected for testing its in vivo activity against melanoma. Cellular and animal activities are reported.

Development and Therapeutic Potential of NUAKs Inhibitors.

NUAK isoforms, NUAK1 (ARK5) and NUAK2 (SNARK), are important members of the AMPK family of protein kinases. They are involved in a broad spectrum of physiological and cellular events, and sometimes their biological roles overlap. NUAK isoform dysregulation is associated with numerous pathological disorders, including neurodegeneration, metastatic cancer, and diabetes. Therefore, they are promising therapeutic targets in metabolic diseases and cancers; consequently, various NUAK-targeted inhibitors have been disclosed. The first part of this review comprises a brief discussion of the homology, expression, structure, and characteristics of NUAK isoforms. The second part focuses on NUAK isoforms' involvement in crucial biological operations, including mechanistic findings, highlighting how their abnormal functioning contributes to disease progression and quality of life. The third part summarizes the key findings and applications of targeting NUAK isoforms for treating multiple cancers and neurodegenerative disorders. The final part systematically presents a critical review and analysis of the literature on NUAK isoform inhibitions through small molecules.

Modification of imidazothiazole derivatives gives promising activity in B-Raf kinase enzyme inhibition; synthesis, in vitro studies and molecular docking.

B-Raf mutation was identified as a key target in cancer treatment. Based on structural features of dabrafenib (potent FDA approved B-Raf inhibitor), the design of new NH2-based imidazothiazole derivatives was carried out affording new highly potent derivatives of imidazothiazole-based scaffold with amino substitution on the terminal phenyl ring as well as side chain with sulfonamide group and terminal substituted phenyl ring. In vitro enzyme assay was investigated against V600E B-Raf kinase. Compounds 10l, 10n and 10o showed higher inhibitory activities (IC50 = 1.20, 4.31 and 6.21 nM, respectively). In vitro cytotoxicity evaluation was assessed against NCI-60 cell lines. Most of tested derivatives showed cytotoxic activities against melanoma cell line. Compound 10k exhibited most potent activity (IC50 = 2.68 µM). Molecular docking study revealed that the new designed derivatives preserved the same binding mode of dabrafenib with V600E B-Raf active site. It was investigated that the new modification in the synthesized derivatives (substituted with NH2) had a significant inhibitory activity towards V600E B-Raf. This core scaffold is considered a key compound for further structural and molecular optimization.

Design and synthesis of novel pyrrolo[2,3-b]pyridine derivatives targeting V600EBRAF.

Several pyrrolo[2,3-b]pyridine-based B-RAF inhibitors are well known and some of them are currently FDA approved as anticancer agents. Based on the structure of these FDA approved V600EB-RAF inhibitors, two series of pyrrolo[2,3-b]pyridine scaffold were designed and synthesized in attempt to develop new potent V600EB-RAF inhibitors. The 38 synthesized compounds were biologically evaluated for their V600EB-RAF inhibitory effect at single dose (10 µM). Compounds with high percent inhibition were tested to determine their IC50 over V600EB-RAF. Compounds 34e and 35 showed the highest inhibitory effect with IC50 values of 0.085 µM and 0.080 µM, respectively. Headed for excessive biological evaluation, the synthesized derivatives were tested over sixty diverse human cancer cell lines. Only compound 35 emerged as a potent cytotoxic agent against different panel of human cancer cell lines.

Design, synthesis, and anticancer activity of imidazo[2,1-b]oxazole-based RAF kinase inhibitors.

In the present work, a novel series of B-RAF kinase inhibitors having imidazo[2,1-b]oxazole scaffold was designed and synthesized based on the structures of the well-known B-RAF inhibitors. The twenty two final compounds were tested over A375 and SKMEL28 cell lines to determine the primary cytotoxic activity of these compounds, and their activities were compared with that of sorafenib as a standard. Compounds 11c, 11e, 11o, 11q, 11r, and 11u exhibited higher cellular activity compared to sorafenib with IC50 values of 7.25, 8.03, 9.81, 8.47, 4.70, and 9.04 µM, respectively and 10.38 µM for sorafenib. In addition, the target compounds were screened for their anticancer activity by the NCI-60 cell line assay. Compounds 11v and 11u were the most active compounds with percent inhibition reached 95.99% for 11v and 87.03% for 11u over K562 cell line at 10 µM concentration. Compound 11v was selected for 5-dose test mode. Furthermore, the kinase inhibitory activities of 11a, 11c, 11e, 11i, 11o, 11q, 11r, 11u, and 11v were determined against wild-type B-RAF, V600E-B-RAF, and RAF1. Compound 11o was the most potent against V600E-B-RAF with IC50 34 nM followed by 11q and 11u with IC50 92 and 93 nM, respectively.

Design, synthesis, in vitro potent antiproliferative activity, and kinase inhibitory effects of new triarylpyrazole derivatives possessing different heterocycle terminal moieties.

A new series of triarylpyrazole derivatives having different heterocycle terminal groups have been designed and synthesised. Compounds 1h-j and 1l exhibited the highest mean percentage inhibition against the 58 cancer cell lines at a concentration of 10 µM, and thus were next examined in 5-dose testing mode to detect their IC50 value. The four compounds showed stronger antiproliferative activities upon comparing their results with sorafenib as a reference compound. Among them, compounds 1j and 1l possessing N-ethylpiperazinyl and N-benzylpiperazinyl terminal moiety through ethylene linker showed the greatest values of mean percentage inhibition (97.72 and 107.18%, respectively) over the 58-cell line panel at 10 µM concentration. The IC50 values of compound 1j over several cancer cell lines were in submicromolar scale (0.26 ∼ 0.38 µM). Moreover, the compounds 1j and 1l showed highly inhibitory activities (99.17 and 97.92%) against V600E-B-RAF kinase.

Synthesis of New Triarylpyrazole Derivatives Possessing Terminal Sulfonamide Moiety and Their Inhibitory Effects on PGE2 and Nitric Oxide Productions in Lipopolysaccharide-Induced RAW 264.7 Macrophages.

This article describes the design, synthesis, and in vitro anti-inflammatory screening of new triarylpyrazole derivatives. A total of 34 new compounds were synthesized containing a terminal arylsulfonamide moiety and a different linker between the sulfonamide and pyridine ring at position 4 of the pyrazole ring. All the target compounds were tested for both cytotoxicity and nitric oxide (NO) production inhibition in lipopolysaccharide (LPS)-induced RAW 264.7 macrophages. Compounds 1b, 1d, 1g, 2a, and 2c showed the highest NO inhibition percentages and the lowest cytotoxic effect. The most potent derivatives were tested for their ability to inhibit prostaglandin E2 (PGE2) in LPS-induced RAW 264.7 macrophages. The IC50 for nitric oxide inhibition, PGE2 inhibition, and cell viability were determined. In addition, 1b, 1d, 1g, 2a, and 2c were tested for their inhibitory effect on LPS-induced inducible nitric oxide synthase (iNOS) and Cyclooxygenase 2 (COX-2) protein expression as well as iNOS enzymatic activity.

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 and synthesis of new RAF kinase-inhibiting antiproliferative quinoline derivatives. Part 2: Diarylurea derivatives.

This article describes the design, synthesis, and biological screening of a new series of diarylurea derivatives possessing quinoline nucleus. Nine target compounds were selected by the National Cancer Institute (NCI, Bethesda, Maryland, USA) for in vitro antiproliferative screening against a panel of 58 cancer cell lines of nine cancer types. Following one-dose initial screening, compounds 1d-g and 2b were selected for 5-dose screening in order to calculate their IC50 and total growth inhibition (TGI) values against the cell lines. Compounds 1e and 1g were the most promising analogues. Both compounds showed strong potency and broad-spectrum antiproliferative activity against the different tested cancer types. Their IC50 and TGI values were less than those of the reference drug, sorafenib, against most of the tested cell lines of the nine different cancer types. Furthermore, the most potent compounds 1d-g were tested against C-RAF kinase as a potential molecular target of this series of compounds. All of them showed high potency, and the most potent derivative was compound 1e (IC50 = 0.10 µM). It was further tested against a panel of another twelve kinases, and it showed selectivity against C-RAF kinase. This could be, at least in part, the possible mechanism of antiproliferative action of this series of compounds at molecular level. The binding modes of compounds 1e and 1g were studied by docking studies, which highlighted the importance of the urea linker compared with the amide linker.

Synthesis, in vitro Antiproliferative and Antiinflammatory Activities, and Kinase Inhibitory effects of New 1,3,4-triarylpyrazole Derivatives.

BACKGROUND: Pyrazole derivatives have been reported as both anticancer and antiinflammatory agents. OBJECTIVE: This study was conducted to develop new pyrazole derivatives as potential anticancer and/or antiinflammatory agents. Their molecular mechanisms of action have been investigated. METHOD: a series of new triarylpyrazole derivatives were synthesized. Their in vitro anticancer activity was tested against NCI-58 cancer cell line panel of nine cancer types. The most active compound 1a was tested against sixteen kinases, many of them are known to be over-expressed in leukemia and breast cancer. The most sensitive kinases were V600E-B-RAF, C-RAF, FLT3, and P38α/MAPK14. Compound 1a was further tested for caspase-3/7 activity and LDH release assay as measures of its apoptotic and necrotic activities against RPMI-8226. Moreover, the ability of compounds 1a, 1b, and 1g to inhibit nitric oxide and prostaglandin Eproduction in LPS-induced RAW 264.7 macrophages was also examined. RESULTS: Compounds 1a, 1c, and 1g showed the highest activities against the cancer cell line panel, with more inhibitory effects against leukemia and breast cancer subpanels. The highest activity was exerted by compound 1a. Its IC50 values against RPMI-8226, K-562 leukemia cell lines, and MDA-MB-468 breast cancer cell line were 1.71 µM, 3.42 µM, and 6.70 µM, respectively. The IC50 of compound 1a against P38α/MAPK14 kinase was 0.515 µM. The caspase activity was increased by 72% and 170% at 1.23 µM and 3.70 µM concentrations of compound 1a, respectively. Furthermore, compound 1b inhibited 80.26% and 95.31% of NO and PGE2 productions, respectively, at 50 µM concentration in the LPS-induced RAW 264.7 macrophages. CONCLUSION: Compound 1a could kill the cells through induction of apoptosis rather than necrosis. Compound 1a was more selective against cancer cells than non-cancerous cells. In addition, the hydroxyl analogue 1b was the most active as antiinflammatory agent.

Synthesis of novel arylaminoquinazolinylurea derivatives and their antiproliferative activities against bladder cancer cell line.

A novel series of arylurea and arylamide derivatives 1a-z, 2a-d having aminoquinazoline scaffold was designed and synthesized. Their in vitro antiproliferative activities against RT112 bladder cancer cell line and inhibitory activities against FGFR3 kinase were tested. Most compounds showed good antiproliferative activities against RT112 bladder cancer cell line, and arylurea compounds 1a-z were more potent than arylamide compounds 2a-d. Among them, eight compounds 1a, 1d-g, 1l, 1y, and 1z showed potent activities with GI50 values below submicromolar range. Especially, arylurea compounds 1d and 1g possessing 2,3-dimethyl and 3,4-dimethyl moieties exhibited superior or similar antiproliferative activity (GI50=8.8nM and 30.2nM, respectively) to AZD4547 (GI50=29.2nM) as a reference standard.

Design, synthesis, and in vitro antiproliferative and kinase inhibitory effects of pyrimidinylpyrazole derivatives terminating with arylsulfonamido or cyclic sulfamide substituents.

A novel series of substituted pyrimidine compounds bearing N-phenylpyrazole and terminating with aryl and cyclic sulfonamido moiety were designed, synthesized, and evaluated in vitro as antiproliferative agents against a panel of 53 cell lines of different tissues at the NCI. Among them, compound 1d with p-chlorobenzenesulfonamido terminal moiety, ethylene spacer, and 4-chloro-3-methoxyphenyl ring at position 3 of the pyrazole nucleus showed the highest mean percentage inhibition value over the whole cancer cell line panel at 10 µM concentration. It showed broad-spectrum antiproliferative activity over many cell lines of different cancer types. For instance, compound 1d inhibited the growth of HL-60 (TB), SR leukemia, and T-47D and MCF-7 breast cancer cell line by 135.92%, 119.44%, 95.32%, and 82.03% at 10 µM, respectively. And it inhibited the growth of COLO 205 colon, HT29 colon, BT-549 breast, and ACHN renal cancer cell lines by more than 80% at the same test concentration. However, testing compound 1d upon determining its IC50 against the most sensitive cell lines showed to good extent selectivity against HT29 colon cancer cell line than HL-60 leukemia and MRC-5 lung fibroblasts (normal cells). Compound 1d was further tested against 12 kinases of different kinase families, and the highest inhibitory effect was exerted against RAF1, V600E-B-RAF, and V600K-B-RAF kinases.

Design, synthesis, broad-spectrum antiproliferative activity, and kinase inhibitory effect of triarylpyrazole derivatives possessing arylamides or arylureas moieties.

A novel series of 1,3,4-triarylpyrazole derivatives possessing terminal arylamide or arylurea terminal moieties has been designed and synthesized. Their in vitro antiproliferative activities were investigated against a panel of 58 cell lines of nine different cancer types at the NCI, USA. The urea analogues 2b, 2c, and 2f as well as the amide derivatives 3e and 3f exerted the highest mean % inhibition values over the 58 cell line panel at 10 µM, and thus were further tested in 5-dose testing mode to determine their GI50, TGI, and LC50 values. The above mentioned compounds have shown stronger antiproliferative activities in terms of potency and efficacy upon comparing their results with Sorafenib as a reference compound. Among them, compounds 2c and 2f possessing 3,4-dichlorophenylurea terminal moiety showed the highest mean %inhibition value of about 99.85 and 104.15% respectively over the 58-cell line panel at 10 µM concentration. Also compounds 2b, 3e, and 3f exhibited mean % inhibition over 80% at 10 µM concentration. The GI50 value of compound 3e over K-562 cancer cell line was 0.75 µM. Accordingly, compound 2f was screened over seven kinases at a single-dose concentration of 10 µM to profile its kinase inhibitory activity. Interestingly, the compound showed highly inhibitory activities (90.44% and 87.71%) against BRAF (V600E) and RAF1 kinases, respectively. Its IC50 value against BRAF (V600E) was 0.77 µM. Compounds 2b, 2c, 2f, 3e, and 3f exerted high selectivity towards cancer cell lines than L132 normal lung cells.

Design, synthesis, in vitro antiproliferative evaluation, and kinase inhibitory effects of a new series of imidazo[2,1-b]thiazole derivatives.

Design and synthesis of a new series of 5,6-diarylimidazo[2,1-b]thiazole derivatives possessing terminal aryl sulfonamide moiety are described. Their in vitro antiproliferative activities against a panel of 57 human cancer cell lines of nine different cancer types were tested at the NCI. Compounds 8a, 8b, 8n, 8q, 8t, and 8u showed the highest mean % inhibition values over the 57 cell line panel at 10 µM, and they were further tested in 5-dose testing mode to determine their IC50 values. Among the six compounds, compound 8u possessing terminal para-hydroxybenzenesulfonamido moiety and ethylene linker showed the highest potency. It demonstrated superior potency than Sorafenib against eight different cell lines, and was equipotent to Sorafenib against COLO 205 colon cancer cell line. Its IC50 values over NCI-H460 non-small cell lung cancer cell line and MCF7 breast cancer cell line were 0.845 µM and 0.476 µM, respectively. Compounds 8a, 8b, 8q, 8t, and 8u showed high selectivity indices towards cancer cells over L132 normal lung cell line. Compound 8u showed potential inhibitory effects over the components of ERK pathway. Its IC50 value over V600E-B-RAF and C-RAF kinases were 39.9 nM and 19.0 nM, respectively.

Synthesis and broad-spectrum antiproliferative activity of diarylamides and diarylureas possessing 1,3,4-oxadiazole derivatives.

A series of diarylamides and diarylureas possessing 1,3,4-oxadiazole scaffold was designed and synthesized. Their in vitro antiproliferative activities were tested against a panel of 58 cell lines of nine different cancer types at the NCI, and compared with Sorafenib as a reference compound. Most of the compounds showed strong and broad-spectrum antiproliferative activities. The diarylurea compound 2g possessing 4-chloro-3-(trifluoromethyl)phenyl terminal moiety showed the highest mean % inhibition value of about 100% over the 58-cell line panel at 10µM concentration. Also compounds 2h, 2l, 2m exhibited mean % inhibition over 90% at 10µM concentration. The IC50 value of compound 2b over SNB-75 CNS cancer cell line was 0.65µM. Compound 2h also exerted submicromolar IC50 values of 0.67, 0.80, and 0.87µM against PC-3 prostate cancer cell line, HCT-116 colon cancer cell line, and ACHN renal cancer cell line, respectively. Compound 2h showed comparable efficacy to Sorafenib.

Synthesis and in vitro antiproliferative activity of new 1,3,4-oxadiazole derivatives possessing sulfonamide moiety.

Synthesis of a new series of 1,3,4-oxadiazole derivatives possessing sulfonamide moiety is described. Their in vitro antiproliferative activities against NCI-58 human cancer cell lines of nine different cancer types were tested. Compound 1k with p-methoxybenzenesulfonamido moiety showed the highest mean %inhibition value over the 58 cell line panel at 10 µM concentration. It showed broad-spectrum antiproliferative activity over many cell lines of different cancer types. For instance, compound 1k inhibited the growth of T-47D breast cancer cell line by 90.47% at 10 µM. And it inhibited growth of SR leukemia, SK-MEL-5 melanoma, and MDA-MB-468 breast cancer cell lines by more than 80% at the same test concentration. Compound 1k showed superior activity than Paclitaxel and Gefitinib against the most sensitive cell lines.

Synthesis and biological evaluation of new pyrazol-4-ylpyrimidine derivatives as potential ROS1 kinase inhibitors.

With the aim of discovering potent and selective kinase inhibitors targeting ROS1 kinase, we designed, synthesized and screened a series of new pyrazol-4-ylpyrimidine derivatives based on our previously discovered lead compound KIST301072. Compounds 6a-e and 7a-e showed good to excellent activities against ROS1 kinase, and seven out of tested compounds were more potent than KIST301072. Compound 7c was the most potent with IC50 of 24 nM. Moreover, compound 7c showed ROS1 inhibitory selectivity of about 170-fold, relative to that of ALK sharing about 49% amino acid sequence homology with ROS1 kinase in the kinase domain. In silico modeling of 7c at ROS1 active site revealed some essential features for ROS1 inhibitory activity. Based on this study as well as the previous studies, we could build a hypothetical model predicting the required essential features for ROS1 inhibitory activity. The model validity has been tested through a second set of compounds.

Synthesis of quinolinylaminopyrimidines and quinazolinylmethylaminopyrimidines with antiproliferative activity against melanoma cell line.

Synthesis of a new series of quinolinylaminopyrimidines 1a-k and quinazolinylmethylaminopyrimidines 2a-i containing aminoquinoline and aminoquinazoline as hinge regions is described. Their in vitro antiproliferative activities against A375P human melanoma cell line were tested. Among them, compounds 1h and 1k exhibited the highest antiproliferative activities against A375P cell line with IC50 values in sub-micromolar scale. Compounds 1i, 2b and 2g showed similar potency against A375P to Sorafenib as a reference compound. The representative compound 1h showed high, dose-dependent inhibition of MEK and ERK kinases.

HOX-7 suppresses body weight gain and adipogenesis-related gene expression in high-fat-diet-induced obese mice.

BACKGROUND: HOX-7 is a newly developed dietary formula composed of traditional oriental herbal medicines. The formula was developed with the aim of improving weight control. We investigated the anti-obesity effect of HOX-7 on high-fat-diet (HFD)-induced obesity in C57BL/6 mice. METHODS: The mice were divided into four groups and were fed a normal diet (ND), HFD, or HFD with oral administration of HOX-7 at 100 or 200 mg/kg/day for 12 weeks. Body and fat weight, histological changes of fat tissue, and the expression of key adipogenic transcription factors were investigated. RESULTS: The body weight of mice fed the HFD with HOX-7 was significantly decreased compared to the HFD group. There were no obvious differences in weekly food intake among the 4 groups. The weight of the epididymal and total fat pads was reduced in mice fed the HFD with HOX-7. Treatment with HOX-7 also substantially attenuated the expression of key adipogenic transcription factors, including peroxisome proliferator-activated receptor γ, CCAAT/enhancer binding protein α, sterol regulatory element binding protein 1c, adipocyte P2, liver X receptor, and lipoprotein lipase in the epididymal adipose tissue. CONCLUSION: Overall, this study highlighted the anti-obesity effects of HOX-7, a finding that could contribute to the development of natural anti-obesity herbal medicines.

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.