A novel DDR1 inhibitor enhances the anticancer activity of gemcitabine in pancreatic cancer.

Pancreatic ductal adenocarcinoma (PDAC) is an extracellular matrix (ECM)-rich carcinoma, which promotes chemoresistance by inhibiting drug diffusion into the tumor. Discoidin domain receptor 1 (DDR1) increases tumor progression and drug resistance by binding to collagen, a major component of tumor ECM. Therefore, DDR1 inhibition may be helpful in cancer therapeutics by increasing drug delivery efficiency and improving drug sensitivity. In this study, we developed a novel DDR1 inhibitor, KI-301690 and investigated whether it could improve the anticancer activity of gemcitabine, a cytotoxic agent widely used for the treatment of pancreatic cancer. KI-301690 synergized with gemcitabine to suppress the growth of pancreatic cancer cells. Importantly, its combination significantly attenuated the expression of major tumor ECM components including collagen, fibronectin, and vimentin compared to gemcitabine alone. Additionally, this combination effectively decreased mitochondrial membrane potential (MMP), thereby inducing apoptosis. Further, the combination synergistically inhibited cell migration and invasion. The enhanced anticancer efficacy of the co-treatment could be explained by the inhibition of DDR1/PYK2/FAK signaling, which significantly reduced tumor growth in a pancreatic xenograft model. Our results demonstrate that KI-301690 can inhibit aberrant ECM expression by DDR1/PYK2/FAK signaling pathway blockade and attenuation of ECM-induced chemoresistance observed in desmoplastic pancreatic tumors, resulting in enhanced antitumor effect through effective induction of gemcitabine apoptosis.

Discovery of a novel NUAK1 inhibitor against pancreatic cancer.

The novel (nua) kinase family 1 (NUAK1) is an AMPK-related kinase and its expression is associated with tumor malignancy and poor prognosis in several types of cancer, suggesting its potential as a target for cancer therapy. Therefore, the development of NUAK1-targeting inhibitors could improve therapeutic outcomes in cancer. We synthesized KI-301670, a novel NUAK1 inhibitor, and assessed its anticancer effects and mechanism of action in pancreatic cancer. It effectively inhibited pancreatic cancer growth and proliferation, and induced cell cycle arrest, markedly G0/G1 arrest, by increasing the expression of p27 and decreasing expression of p-Rb and E2F1. Additionally, the apoptotic effect of KI-301670 was observed by an increase in cleaved PARP, TUNEL-positive cells, and annexin V cell population, as well as the release of cytochrome c via the loss of mitochondrial membrane potential. KI-301670 inhibited the migration and invasion of pancreatic cancer cells. Mechanistically, KI-301670 effectively inhibited the PI3K/AKT pathway in pancreatic cancer cells. Furthermore, it significantly attenuated tumor growth in a mouse xenograft tumor model. Our results demonstrate that a novel NUAK1 inhibitor, KI-301670, exerts anti-tumor effects by directly suppressing cancer cell growth by affecting the PI3K/AKT pathway, suggesting that it could be a novel therapeutic candidate for pancreatic cancer treatment.

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.

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).

Synthesis and In Vitro Antiproliferative Activity of New 1-Phenyl-3-(4-(pyridin-3-yl)phenyl)urea Scaffold-Based Compounds.

A new series of 1-phenyl-3-(4-(pyridin-3-yl)phenyl)urea derivatives were synthesized and subjected to in vitro antiproliferative screening against National Cancer Institute (NCI)-60 human cancer cell lines of nine different cancer types. Fourteen compounds 5a-n were synthesized with three different solvent exposure moieties (4-hydroxylmethylpiperidinyl and trimethoxyphenyloxy and 4-hydroxyethylpiperazine) attached to the core structure. Substituents with different π and σ values were added on the terminal phenyl group. Compounds 5a-e with a 4-hydroxymethylpiperidine moiety showed broad-spectrum antiproliferative activity with higher mean percentage inhibition values over the 60-cell line panel at 10 µM concentration. Compound 5a elicited lethal rather than inhibition effects on SK-MEL-5 melanoma cell line, 786-0, A498, RXF 393 renal cancer cell lines, and MDA-MB-468 breast cancer cell line. Two compounds, 5a and 5d showed promising mean growth inhibitions and thus were further tested at five-dose mode to determine median inhibitory concentration (IC50) values. The data revealed that urea compounds 5a and 5d are the most active derivatives, with significant efficacies and superior potencies than paclitaxel in 21 different cancer cell lines belonging particularly to renal cancer and melanoma cell lines. Moreover, 5a and 5d had superior potencies than gefitinib in 38 and 34 cancer cell lines, respectively, particularly colon cancer, breast cancer and melanoma cell lines.

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.

Synthesis of new diarylamides with pyrimidinyl pyridine scaffold and evaluation of their anti-proliferative effect on cancer cell lines.

A new series of diarylamides, having a pyrimidinyl pyridine scaffold, was designed and synthesized. The target compounds were synthesized in three steps. A selected group from the target compounds was tested over a panel of 60 cancer cell lines at a single dose concentration of 10 µM, and the most active compound, 5j, was further tested in a five-dose testing mode to determine its IC50 value over the 60 cell lines. In single-dose testing mode, compound 5j showed the highest growth inhibition against the NCI-60 cancer cell lines, while other tested compounds showed a weak to moderate inhibitory activity against a range of different cancer cell lines. In five-dose testing mode, compound 5j showed strong inhibitory activity in micro molar range against many cancer cell lines. Its major activity was against melanoma cancer cell lines. Therefore, compound 5j is a promising hit compound targeting this severe form of cancer.

ROS1 amplification mediates resistance to gefitinib in glioblastoma cells.

Glioblastoma (GBM) is the most aggressive brain tumor in adults and remains incurable despite multimodal intensive treatment regimens. The majority of GBM tumors show a mutated or overexpressed EGFR, however, tumors treated with tyrosine kinase inhibitors (TKIs) will inevitably recur highlighting the need to identify signalling pathways involved in GBM resistance to these drugs. To this end, we treated GBM cells that overexpress EGFR with increasing concentrations of gefitinib and isolated resistant clones. These resistant clones were subject to RNAseq and the expression of several genes was found to be upregulated. These genes are mainly tyrosine kinase receptors and include ROS1, DDR1 and PDGFRA and are known to control several downstream targets of EGFR. The upregulation of ROS1 and DDR1 was confirmed at the protein level by western blot. Treatment with a potent and highly specific pyrazole ROS1 inhibitor in ROS1 overexpressing clones led to a sensitization of these cells to low concentrations of gefitinib. Combined treatment with gefitinib and ROS1 inhibitor induces massive cell death by apoptosis following a prolonged S phase cell cycle arrest. Our current study led to the discovery of alternative pathways used by GBM cells to evade cell death following treatment with gefitinib and identifies new therapeutic targets to prevent GBM cell resistance to the drug.

Synthesis and in vitro screening of phenylbipyridinylpyrazole derivatives as potential antiproliferative agents.

A series of phenylbipyridinylpyrazoles was synthesized through the reaction of 2-(4-(2-chloropyridin-4-yl)-3-(3-methoxy-5-methylphenyl)-1H-pyrazol-1-yl)acetonitrile (4) with different 6-substituted pyridine-3-ylboronic acids. The final compounds 5a-j were screened at 10 µM against over 60 tumor cell lines at the U.S. National Cancer Institute (NCI). In light of the NCI results, compounds 5c and 5h showed a broad spectrum of activity against NCI cell lines with mean growth of 53% and 58%, respectively. Compound 5e behaved differently as it showed high degree of selectivity and potency by inhibiting 96% of growth of leukemia SR cell line at 10 µM. Standard COMPARE analyses were performed at the GI50 level and the results exhibit high correlation in the form of pairwise correlation coefficient (PCC) of more than 0.6 between three of the current compounds and three standard known anticancer agents. Compound 5e demonstrated high correlation levels with merbarone (NSC S336628) with a PCC value of 0.631. Compound 5h showed a considerably high PCC value of 0.626 with dichloroallyl lawsone, while compound 5i, showed PCC values of 0.601 and 0.604 with both dichloroallyl lawsone and N,N-dibenzyldaunomycin (NSC S268242), respectively. These three standard agents have anticancer activity via two major mechanism of actions, inhibition of topoisomerase II and inhibition of biosynthesis of pyrimidine nucleotides, therefore, compounds 5a-j are promising therapeutic agents for targeting different human malignancies. Prediction of drug-likeness and toxicity of these newly synthesized derivatives were also considered.

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.

Synthesis and biological evaluation of new pyrimidine-4-yl-ethanol derivatives as ROS1 kinase inhibitors.

As a part of trials to target ROS1 kinase with potential inhibitors, a novel series of pyrimidin-4-yl-ethanol and ethanone derivatives (4a-f, 5a-f, 6a-f and 7a-f) have been designed based on previously discovered lead compounds KIST301072 and KIST301080, and synthesized on 4-5 steps according to compounds. The structures of the newly synthesized compounds have been confirmed on (1)H-NMR, (13)C-NMR and IR. Most of the tested compounds showed ROS1 kinase inhibitory activity in micromolar range.

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.

New diarylamides and diarylureas possessing 8-amino(acetamido)quinoline scaffold: synthesis, antiproliferative activities against melanoma cell lines, kinase inhibition, and in silico studies.

Synthesis of a new series of diarylureas and diarylamides possessing 4-aryl-8-amino(acetamido)quinoline scaffold is described. Their in vitro antiproliferative activities against ten melanoma cell lines were tested. Compounds 1l, 2l, 3c, and 4c showed the highest potency against A375P cell line with IC50 values in sub-micromolar scale. Compound 4c was equipotent to Vemurafenib against A375P. In addition, compounds 1l, 2a, and 2l showed high potency over the NCI-9 tested melanoma cell line panel. The IC50 values of compounds 1l and 2l were in 2-digit nanomolar scale over four and five cell lines, respectively. Compound 2l showed high, dose-dependent inhibition of ERK kinase. ADME profiling showed that compounds 1l, 2l, 3c, 4c, and 5b are estimated to be orally bioavailable.

Novel quinolinylaminoisoquinoline bioisosteres of sorafenib as selective RAF1 kinase inhibitors: design, synthesis, and antiproliferative activity against melanoma cell line.

Design and synthesis of a new series of quinolinylaminoisoquinoline derivatives as conformationally restricted bioisosteres of Sorafenib are described. Their in vitro antiproliferative activity against A375P melanoma cell line was tested. Compounds 1b, 1d, 1g, and 1j showed the highest potency against A375P cell line with IC50 values in sub-micromolar scale. In addition, compound 1d exerted high selectivity towards RAF1 serine/threonine kinase with 96.47% inhibition at 10 µM, and IC50 of 0.96 µM. This compound can possess antiproliferative activity against melanoma cells through inhibition of RAF1 kinase.

Anticancer effects of KI-10F: a novel compound affecting apoptosis, angiogenesis and cell growth in colon cancer.

The anticancer effect of a new pyrazole derivative, KI-10F (2-(4-(2-(4-(dimethylamino) phenyl)pyridin-4-yl)-5-(3-methoxy-5-methylphenyl)-1H-pyrazol­1-yl) acetonitrile)•3.5HCl) was evaluated in human colon cancer cells. KI-10F strongly suppressed the growth of human colon cancer cells and induced apoptosis by increasing the proportion of sub-G1 presenting apoptotic cells as well as causing cell cycle arrest at the G2/M phase. Apoptosis by KI-10F was confirmed by observation of an increase in the expression of cleaved caspase-3, caspase-8, caspase-9 and Bax, and the decrease of Bcl-2. Decreased expression of HIF-1α and VEGF, and the inhibition of HUVEC tube formation and migration showed that KI-10F effectively inhibited the angiogenesis process. Furthermore, in vivo study in a mouse xenograft model showed that KI-10F produced a stronger antitumor activity than 5-FU, a conventional anticancer drug prescribed for the treatment of colon cancer. The effects of KI-10F on tumor proliferation (PCNA), angiogenesis (CD34) and apoptosis (cleaved caspase-3) were evaluated by immunohistochemistry using isolated tumor tissue samples. Taken together, our results demonstrated that KI-10F induces apoptosis and inhibits cell growth and angiogenesis both in vitro and in vivo. We suggest that KI-10F is an effective chemotherapeutic candidate for use against colon cancer.

New diarylureas and diarylamides possessing acet(benz)amidophenyl scaffold: design, synthesis, and antiproliferative activity against melanoma cell line.

A series of new diarylurea and diarylamide derivatives possessing acet(benz)amidophenyl scaffold was synthesized. Their in vitro antiproliferative activity was tested against A375P human melanoma cell line. Compounds 1c,d and 2c,d showed the highest potencies with IC(50) values in sub-micromolar scale. In addition, compounds 1b,e,l and 2e,l were more potent than Sorafenib but with IC(50) values in micromolar range. Moreover, compound 2c was equipotent to Vemurafenib, and 2d showed higher potency than Vemurafenib against A375P. Molar refractometry calculation and ADME profiling of the highest potent four derivatives 1c,d and 2c,d are also reported.

ROS receptor tyrosine kinase: a new potential target for anticancer drugs.

ROS kinase is one of the last two remaining orphan receptor tyrosine kinases with an as yet unidentified ligand. The normal functions of human ROS kinase in different body tissues have not been fully identified so far. However, the ectopic expression, as well as the production of variable mutant forms of ROS kinase has been reported in a number of cancers, such as glioblastoma multiforme, and non-small cell lung cancer, suggesting a role for ROS kinase in deriving such tumors. It is thought also that c-ROS gene may have a role in some cardiovascular diseases, and the fact that homozygous male mice targeted against c-ROS gene are healthy but infertile, has inspired researchers to think about ROS inhibition as a method for development of new male contraceptives. The recent discovery of new selective and potent inhibitors for ROS kinase, along with the development of new specific diagnostic methods for the detection of ROS fusion proteins, raises the importance of using these selective inhibitors for targeting ROS mutations as a new method for treatment of cancers harboring such genes. This review focuses on the ectopic expression of ROS and its fusion proteins in different cancer types and highlights the importance of targeting these proteins for treatment of substantial cancers. It describes also the recent advances in the field of ROS kinase inhibition, and the potential clinical applications of ROS kinase inhibitors.

Synthesis of aminoquinazoline derivatives and their antiproliferative activities against melanoma cell line.

The synthesis of a novel series of aminoquinazoline derivatives 1a-r and their antiproliferative activities against A375 human melanoma cell line were described. Among them, six compounds showed superior antiproliferative activities to Sorafenib as a reference compound. In particular, the representative compound 1q bearing chromen-4-one moiety exhibited excellent antiproliferative activity (IC(50)=0.006 µM) and good selectivity over HS27 fibroblast cell line.

Design and synthesis of new potent anticancer pyrazoles with high FLT3 kinase inhibitory selectivity.

A new series of 1H- and 2H-pyrazole derivatives (35 final compounds) has been designed and synthesized in this study. A selected group (13 compounds) was then tested over a panel of 60 cancer cell lines at a single dose concentration of 10microM. At this concentration, six compounds have showed moderate to strong mean inhibitions, and were further tested at five-dose testing mode to determine their IC(50) over the 60 cell lines. The IC(50) values of the tested compounds indicated high potency (as for compound 10f) as well as high efficacy (as for compound 11e). Accordingly, compound 10f was then tested at a single dose concentration of 10microM over a panel of 54 kinases to determine its kinase inhibitory profile. The compound has showed good selectivity towards FLT3 kinase, associated with a moderate potency, with an IC(50) value of 1.74microM.