Nuclear Localization of Fibroblast Growth Factor Receptor 1 in Breast Cancer Cells Interacting with Cancer Associated Fibroblasts.

Cancer-associated fibroblasts (CAFs) represent a major component of the tumor microenvironment and interplay with cancer cells by secreting cytokines, growth factors and extracellular matrix proteins. When estrogen receptor-negative breast cancer MDA-MB-231 cells were treated with the CAF-conditioned medium (CAF-CM), Akt and STAT3 involved in cell proliferation and survival were activated through phosphorylation. CAFs secrete fibroblast growth factor 2 (FGF2), thereby stimulating breast cancer cell progression. Akt activation induced by CAF-CM in MDA-MB-231 cells was abolished when FGF2-neutralizing antibody was added. Treatment of MDA-MB-231 cells directly with FGF2 enhanced the phosphorylation of Akt and the FGF receptor (FGFR) substrate, FRS2α. These events were abrogated by siRNA-mediated silencing of FGFR1. In a xenograft mouse model, co-injection of MDA-MB-231 cells with activated fibroblasts expressing FGF2 dramatically enhanced activation of Akt. Stable knockdown of FGFR1 blunted Akt phosphorylation in xenograft tumors. MDA-MB-231 cells co-cultured with CAFs or directly stimulated with FGF2 exhibited enhanced nuclear localization of FGFR1. Notably, FGF2 stimulation produced reactive oxygen species (ROS) accumulation in MDA-MB-231 cells, and FGF2-induced nuclear accumulation of FGFR1 was abrogated by the ROS scavenging agent, N-acetylcysteine.

STAT3 as a Potential Target for Tumor Suppressive Effects of 15-Deoxy-Δ12,14-prostaglandin J2 in Triple Negative Breast Cancer.

STAT3 plays a prominent role in proliferation and survival of tumor cells. Thus, STAT3 has been considered to be a prime target for development of anti-cancer therapeutics. The electrophilic cyclopentenone prostaglandin,15-deoxy-Δ12,14-prostaglandin J2 (15d-PGJ2) has been well recognized for its capability to modulate intracellular signaling pathways involved in cancer cell growth and progression. We previously reported that 15d-PGJ2 had potent cytotoxicity against harvey-ras transformed human mammary epithelial cells through direct interaction with STAT3. In this study, we have attempted to verify the inhibitory effects of 15d-PGJ2 on STAT3 signaling in human breast tumor cells. The triple negative breast cancer cell lines, MDA-MB-231 and MDA-MB-468 displaying constitutive phosphorylation of STAT3 on the tyrosine 705 (Tyr705) residue, underwent apoptosis upon inhibition of STAT3 by 15d-PGJ2. In contrast, estrogen receptor positive MCF-7 breast cancer cells that do not exhibit elevated STAT3 phosphorylation were much less susceptible to 15d-PGJ2-induced apoptosis as assessed by PARP cleavage. Furthermore, 15d-PGJ2 inhibited interleukin-6-induced tyrosine phosphorylation of STAT3 in LNCaP cells. According to molecular docking studies, 15d-PGJ2 may preferentially bind to the cysteine 259 residue (Cys259) present in the coiled-coil domain of STAT3. Site-directed mutagenesis of STAT3 identified Cys259 to be the critical amino acid for the 15d-PGJ2-induced apoptosis as well as epithelial-to-mesenchymal transition. Taken together, these findings suggest STAT3 inactivation through direct chemical modification of its Cys259 as a potential therapeutic approach for treatment of triple negative breast cancer treatment.

Aberrant activation of the CD45-Wnt signaling axis promotes stemness and therapy resistance in colorectal cancer cells.

Rationale: Chemoradiation (CRT) is commonly used as an adjuvant or neoadjuvant treatment for colorectal cancer (CRC) patients. However, resistant cells manage to survive and propagate after CRT, increasing the risk of recurrence. Thus, better understanding the mechanism of resistant cancer cells is required to achieve better clinical outcomes. Methods: Here, we explored gene expression profiling of CRC patient tumors to identify therapy resistance genes and discovered that protein tyrosine phosphatase receptor type C (PTPRC), which encodes CD45, was increased in remnant tumor tissues after CRT and correlated with metastasis. Through multiple validations using patient tumors and CRC cell lines, we found for the first time the increase of CD45 expression in CRC (EpCAM+) epithelial cells surviving after CRT. Thus, we investigated the biological role and downstream events of CD45 were explored in human CRC cells and CRC mouse models. Results: Increased CD45 expression in cancer cells in pretreated primary tumors accounts for poor regression and recurrence-free survival in CRT-treated patients. High CD45 expression promotes CRC cell survival upon 5-fluorouracil or radiation treatment, while CD45 depletion sensitizes CRC cells to CRT. Intriguingly, CD45 is preferentially expressed in cancer stem-like cells (CSCs), as determined by spheroid culture and the expression of CSC markers, and is required for the distinct functions of CSCs, such as cancer initiation, repopulation, and metastasis. Mechanistically, CD45 phosphatase activity promotes Wnt transcriptional activity by stabilizing the ß-catenin protein, which collectively enhances stemness and the therapy-resistant phenotype. Conclusions: Our results highlight a novel function of CD45 as a mediator of CRT resistance and provide a potential therapy strategy for CRC therapy.

15-Deoxy-Δ12,14 -prostaglandin J2 binds and inactivates STAT3 via covalent modification of cysteine 259 in H-Ras-transformed human breast epithelial cells.

Signal transducer and activator of transcription 3 (STAT3) has been considered as a potential target for development of anticancer therapeutics. Here, we report a novel mechanism by which the cyclopentenone prostaglandin, 15-deoxy-Δ12,14 -prostaglandin J2 (15d-PGJ2 ) functions as an allosteric inhibitor of STAT3. 15d-PGJ2 inhibits phosphorylation, dimerization, nuclear translocation, and transcriptional activity of STAT3 in H-Ras-transformed human mammary epithelial cells (MCF10A-Ras) through the Michael addition reaction at cysteine 259 of STAT3. Comparative studies with 15d-PGJ2 analogues reveal that both C12-C13 and C9-C10 double bonds conjugated to the carbonyl group in the cyclopentenone ring of 15d-PGJ2 are essential for STAT3 binding. Antiproliferative and pro-apoptotic activities of 15d-PGJ2 in MCF10A-Ras cells are attributable to covalent modification of STAT3 on Cys259, and mimic the effects induced by mutation of this amino acid.

Interaction of Nrf2 with dimeric STAT3 induces IL-23 expression: Implications for breast cancer progression.

Persistent activation of STAT3 and Nrf2 is considered to stimulate the aggressive behavior of basal-like breast cancer (BLBC). However, the precise mechanism underlying sustained overactivation of these transcription factors and their roles in breast cancer progression remain elusive. Analysis of the TCGA multi-omics data showed that high levels of STAT3 and Nrf2 mRNA were correlated with elevated expression of P-STAT3Y705 and Nrf2 target proteins in breast cancer patients. Our present study demonstrates a unique interaction between Nrf2 and STAT3 in the maintenance and progression of BLBC. RNA sequencing analysis identified the gene encoding IL-23A upregulated by concurrent binding of STAT3 and Nrf2 to its promoter. IL-23A depletion also showed the similar phenotypic changes to those caused by double knockdown of both transcription factors. In conclusion, the STAT3-Nrf2 interaction accelerates BLBC growth and progression by augmenting IL-23A expression, which underscores the importance of subtype-specific molecular pathways in human breast cancer.

An Electrophilic Deguelin Analogue Inhibits STAT3 Signaling in H-Ras-Transformed Human Mammary Epithelial Cells: The Cysteine 259 Residue as a Potential Target.

Signal transducer and activator of transcription 3 (STAT3) is a point of convergence for numerous oncogenic signals that are often constitutively activated in many cancerous or transformed cells and some stromal cells in the tumor microenvironment. Persistent STAT3 activation in malignant cells stimulates proliferation, survival, angiogenesis, invasion, and tumor-promoting inflammation. STAT3 undergoes activation through phosphorylation on tyrosine 705, which facilitates its dimerization. Dimeric STAT3 translocates to the nucleus, where it regulates the transcription of genes involved in cell proliferation, survival, etc. In the present study, a synthetic deguelin analogue SH48, discovered by virtual screening, inhibited the phosphorylation, nuclear translocation, and transcriptional activity of STAT3 in H-ras transformed human mammary epithelial MCF-10A cells (MCF10A-ras). We speculated that SH48 bearing an α,ß-unsaturated carbonyl group could interact with a thiol residue of STAT3, thereby inactivating this transcription factor. Non-electrophilic analogues of SH48 failed to inhibit STAT3 activation, lending support to the above supposition. By utilizing a biotinylated SH48, we were able to demonstrate the complex formation between SH48 and STAT3. SH48 treatment to MCF10A-ras cells induced autophagy, which was verified by staining with a fluorescent acidotropic probe, LysoTracker Red, as well as upregulating the expression of LC3II and p62. In conclusion, the electrophilic analogue of deguelin interacts with STAT3 and inhibits its activation in MCF10A-ras cells, which may account for its induction of autophagic death.

Curcumin induces stabilization of Nrf2 protein through Keap1 cysteine modification.

The present study was aimed to investigate the effects of curcumin, a representative chemopreventive phytochemical with pronounced antioxidant and anti-inflammatory properties, on activation of Nrf2 and expression of its target protein heme oxygenase-1 (HO-1) in mouse skin in vivo and in cultured murine epidermal cells. Treatment of mouse epidermal JB6 cells with curcumin resulted in the induction of HO-1 expression, and this was abrogated in cells transiently transfected with Nrf2 siRNA. While curcumin treatment increased protein expression of Nrf2, it did not alter the steady-state level of the Nrf2 mRNA transcript. Treatment of cells with curcumin stabilized Nrf2 by inhibiting ubiquitination and subsequent 26S proteasomal degradation of this transcription factor. Tetrahydrocurcumin, a non-electrophilic analogue of curcumin that lacks the α,ß-unsaturated carbonyl group, failed to induce HO-1 expression as well as nuclear translocation of Nrf2 and its binding to the antioxidant/electrophile response elements. Cells transfected with a mutant Keap1 protein in which cysteine 151 (Cys151) is replaced by serine exhibited marked reduction in curcumin-induced Nrf2 transactivation. Mass spectrometric analysis revealed that curcumin binds to Keap1 Cys151, supporting that this amino acid is a critical target for curcumin modification of Keap1, which facilitates the liberation of Nrf2. Thus, it is likely that the α,ß-unsaturated carbonyl moiety of curcumin is essential for its binding to Keap1 and stabilization of Nrf2 by hampering ubiquitination and proteasomal degradation.

17-Oxo-docosahexaenoic acid induces Nrf2-mediated expression of heme oxygenase-1 in mouse skin in vivo and in cultured murine epidermal cells.

Recently, growing attention has been given to new classes of bioactive lipid mediators derived from ω-3 polyunsaturated fatty acids, such as docosahexaenoic acid (DHA), especially in the context of their role as endogenous signal modulators. One such molecule is 17-oxo-DHA, generated from DHA by the action of COX2 and a dehydrogenase. The redox-sensitive transcription factor, Nrf2 plays a key role in cellular stress responses. In the present study, the effects of 17-oxo-DHA on Nrf2-mediated expression of cytoprotective enzymes were examined in mouse skin in vivo and cultured murine epidermal JB6 cells. Topical application of 17-oxo-DHA markedly elevated the nuclear localization of Nrf2 and expression of heme oxygenase-1 (HO-1) and NAD(P)H:quinone oxidoreductase-1 in hairless mouse skin. In contrast to 17-oxo-DHA, the non-electrophilic metabolic precursor 17-hydroxy-DHA was a much weaker inducer of Nrf2 activation and its target protein expression. Likewise, 17-oxo-DHA significantly enhanced nuclear translocation and transcriptional activity of Nrf2 with concomitant upregulation of HO-1 expression in cultured JB6 cells. 17-Oxo-DHA was a much stronger inducer of Nrf2-mediated antioxidant response than its parent molecule, DHA. HO-1 expression was abolished in Nrf2 knockdown JB6 cells or embryo fibroblasts from Nrf2 knock out mice. 17-Oxo-DHA also markedly reduced the level of Keap1 protein by inducing ubiquitination. Mutation of Cys151 and Cys273 in Keap1 abrogated 17-oxo-DHA-induced ubiquitination and proteasome-mediated degradation of Keap1 as well as HO-1 expression, suggesting that these cysteine residues are putative sites for 17-oxo-DHA binding. Further, Keap1 degradation stimulated by 17-oxo-DHA coincided with accumulation of the autophagy substrate, p62/SQSTM1.

Acetazolamide-based [18F]-PET tracer: In vivo validation of carbonic anhydrase IX as a sole target for imaging of CA-IX expressing hypoxic solid tumors.

Carbonic anhydrase IX is overexpressed in many solid tumors including hypoxic tumors and is a potential target for cancer therapy and diagnosis. Reported imaging agents targeting CA-IX are successful mostly in clear cell renal carcinoma as SKRC-52 and no candidate was approved yet in clinical trials for imaging of CA-IX. To validate CA-IX as a valid target for imaging of hypoxic tumor, we designed and synthesized novel [18F]-PET tracer (1) based on acetazolamide which is one of the well-known CA-IX inhibitors and performed imaging study in CA-IX expressing hypoxic tumor model as 4T1 and HT-29 in vivo models other than SKRC-52. [18F]-acetazolamide (1) was found to be insufficient for the specific accumulation in CA-IX expressing tumor. This study might be useful to understand in vivo behavior of acetazolamide PET tracer and can contribute to the development of successful PET imaging agents targeting CA-IX in future. Additional study is needed to understand the mechanism of poor targeting of CA-IX, as if CA-IX is not reliable as a sole target for imaging of CA-IX expressing hypoxic solid tumors.

Direct interaction with 14-3-3γ promotes surface expression of Best1 channel in astrocyte.

BACKGROUND: Bestrophin-1 (Best1) is a calcium-activated anion channel (CAAC) that is expressed broadly in mammalian tissues including the brain. We have previously reported that Best1 is expressed in hippocampal astrocytes at the distal peri-synaptic regions, called microdomains, right next to synaptic junctions, and that it disappears from the microdomains in Alzheimer's disease mouse model. Although Best1 appears to be dynamically regulated, the mechanism of its regulation and modulation is poorly understood. It has been reported that a regulatory protein, 14-3-3 affects the surface expression of numerous membrane proteins in mammalian cells. METHODS: The protein-protein interaction between Best1 and 14-3-3γ was confirmed by yeast-two hybrid assay and BiFC method. The effect of 14-3-3γ on Best1-mediated current was measured by whole-cell patch clamp technique. RESULTS: We identified 14-3-3γ as novel binding partner of Best1 in astrocytes: among 7 isoforms of 14-3-3 protein, only 14-3-3γ was found to bind specifically. We determined a binding domain on the C-terminus of Best1 which is critical for an interaction with 14-3-3γ. We also revealed that interaction between Best1 and 14-3-3γ was mediated by phosphorylation of S358 in the C-terminus of Best1. We confirmed that surface expression of Best1 and Best1-mediated whole-cell current were significantly decreased after a gene-silencingof 14-3-3γ without a significant change in total Best1 expression in cultured astrocytes. Furthermore, we discovered that 14-3-3γ-shRNA reduced Best1-mediated glutamate release from hippocampal astrocyte by recording a PAR1 receptor-induced NMDA receptor-mediated current from CA1 pyramidal neurons in hippocampal slices injected with adenovirus carrying 14-3-3γ-shRNA. Finally, through a structural modeling, we found critical amino acid residues containing S358 of Best1 exhibiting binding affinities to 14-3-3γ. CONCLUSIONS: 14-3-3γ promotes surface expression of Best1 channel in astrocytes through direct interaction.

Design and synthesis of new 2-anilinoquinolines bearing N-methylpicolinamide moiety as potential antiproliferative agents.

A series of new 2-anilinoquinolines 6a-o possessing the substantial N-methylpicolinamide motif at C5 has been designed and synthesized as sorafenib analogs. The antiproliferative activities of the target compounds were preliminarily appraised against a panel of three human cancer cell lines (MCF-7, SK-BR3, and HCT116), and a selected array was further tested over a panel of approximately 60 cancer cell lines at NCI at 10 µM concentration. Interestingly, compounds 6c, 6d, 6j, 6k, and 6l showed promising selective anticancer activities (growth inhibition >80%) toward certain cancer cells at 10 µM testing dose. Compounds 6d and 6j were advanced to five-dose testing mode to determine their GI50 values and compared with our previously reported ureidoquinoline B and sorafenib as reference compounds. The 4-chloro-3-trifluoromethylaniline derivative 6j manifested superior potency than both compound B and sorafenib over eleven and eight cell lines, respectively. It showed GI50 values of 0.36, 0.66, 0.68, and 0.60 µM against the breast MDA-MB-468, renal A498, and melanoma SK-MEL-5 and UACC-62 cell lines, respectively. Moreover, both 6d and 6j exerted low cytotoxic effects against HFF-1 normal cell line. Furthermore, compounds 6d and 6j were tested against both B-RafV600E and C-Raf kinases and displayed modest inhibitory activities, which were justified by molecular docking study. Compound 6j could serve as a promising candidate for further development of potent anticancer chemotherapeutics.

Discovery of a Nanomolar Multikinase Inhibitor (KST016366): A New Benzothiazole Derivative with Remarkable Broad-Spectrum Antiproliferative Activity.

Herein we report the discovery of compound 6 [KST016366; 4-((2-(3-(4-((4-ethylpiperazin-1-yl)methyl)-3-(trifluoromethyl)phenyl)ureido)benzo[d]thiazol-6-yl)oxy)picolinamide] as a new potent multikinase inhibitor through minor structural modification of our previously reported RAF kinase inhibitor A. In vitro anticancer evaluation of 6 showed substantial broad-spectrum antiproliferative activity against 60 human cancer cell lines. In particular, it showed GI50 values of 51.4 and 19 nm against leukemia K-562 and colon carcinoma KM12 cell lines, respectively. Kinase screening of compound 6 revealed its nanomolar-level inhibitory activity of certain oncogenic kinases implicated in both tumorigenesis and angiogenesis. Interestingly, 6 displays IC50 values of 0.82, 3.81, and 53 nm toward Tie2, TrkA, and ABL-1 (wild-type and T315I mutant) kinases, respectively. Moreover, 6 is orally bioavailable with a favorable in vivo pharmacokinetic profile. Compound 6 may serve as a promising candidate for further development of potent anticancer chemotherapeutics.

Novel 5-substituted-2-anilinoquinolines with 3-(morpholino or 4-methylpiperazin-1-yl)propoxy moiety as broad spectrum antiproliferative agents: Synthesis, cell based assays and kinase screening.

A series of new 2-anilinoquinolines possessing 3-(morpholino or 4-methylpiperazin-1-yl)propoxy moiety at C5 of quinoline has been designed and synthesized as potential anticancer agents. Their antiproliferative activities were evaluated against a panel of 60 cancer cell lines at NCI and compared with gefitinib as a reference compound. Most of the tested compounds displayed potent and broad spectrum antiproliferative activities. Compounds 7d, 7f and 7g showed strong inhibitory and lethal effects at 10µM concentration. Moreover, they manifested superior potencies and efficacies than gefitinib across the most tested cell lines. Compound 7d, with 4-chloro-3-trifluoromethylphenyl group, proved to be the most potent and efficacious derivative in this series, with mean GI50 and TGI values of 1.62µM and 3.47µM, respectively. Kinase screening of 7d against a panel of 47 oncogenic kinases revealed its selective inhibitory effect (96% inhibition) towards TrkA kinase. Furthermore, the most potent compounds showed low cytotoxic effects against HFF-1 normal cell line.

Design and synthesis of new potent anticancer benzothiazole amides and ureas featuring pyridylamide moiety and possessing dual B-Raf(V600E) and C-Raf kinase inhibitory activities.

A new series of benzothiazole amide and urea derivatives tethered with the privileged pyridylamide moiety by ether linkage at the 6-position of benzothiazole (22 final compounds) has been designed and synthesized as potent anticancer sorafenib analogs. A selected group of twelve derivatives was appraised for its antiproliferative activity over a panel of 60 human cancer cell lines at a single dose concentration of 10 µM at National Cancer Institute (NCI, USA). Compounds 4b, 5a, 5b and 5d exhibited promising growth inhibitions and thus were further tested in advanced 5-dose testing assay to determine their GI50 values. The cellular based assay results revealed that 3,5-bis-trifluoromethylphenyl (5b) urea member is the best derivative with superior potency and efficacy compared to sorafenib as well as notable extended spectrum activity covering 57 human cancer cell lines. Kinase screening of compound 5b showed its kinase inhibitory effect against both B-Raf(V600E) and C-Raf. Moreover, the most potent derivatives in cells were investigated for their RAF inhibitory activities, and the results were rationalized with the molecular docking study. Profiling of CYP450 and hERG channel inhibitory effects for the active compounds revealed their low possibilities to exhibit undesirable drug-drug interactions and cardiac side effects.

Immunomodulatory Activities of the Benzoxathiole Derivative BOT-4-One Ameliorate Pathogenic Skin Inflammation in Mice.

T-cell-mediated immune responses play an important role in body protection. However, aberrantly activated immune responses are responsible for inflammatory and autoimmune diseases. The regulation of pathologic immune responses may be a potential therapeutic strategy for the treatment of these diseases. Despite that multiple pharmacologic properties of benzoxathiole derivatives have been defined, the molecular mechanisms underlying these properties remain to be clarified. Here, we demonstrated the benzoxathiole derivative 2-cyclohexylimino-6-methyl-6,7-dihydro-5H-benzo[1,3]oxathiol-4-one (BOT-4-one) regulated immune responses and ameliorated experimentally induced inflammatory skin diseases both in vitro and in vivo. BOT-4-one inhibited the differentiation of CD4(+) T-cell subsets by regulating the expression and production of T-cell lineage-specific master transcription factors and cytokines and activating the signal transducer and activator of transcription proteins. In addition, BOT-4-one inhibited TCR-mediated Akt and NF-κB signaling. Topical application of BOT-4-one ameliorated experimentally induced inflammatory skin diseases in mice models such as 2,4,6-trinitrochlorobenzene-induced contact and atopic dermatitis and IL-23-induced psoriasis-like skin inflammation. Our study demonstrated that BOT-4-one ameliorates inflammatory skin diseases by suppressing the pathogenic CD4(+) T cell differentiation and overall immune responses.

Discovery of a broad spectrum antiproliferative agent with selectivity for DDR1 kinase: cell line-based assay, kinase panel, molecular docking, and toxicity studies.

Herein, we report compound KST9046, a new agent possessing quinazoline-urea scaffold. Preliminary biological evaluation done by the National Cancer Institute (NCI), USA, showed a great inhibitory effect of KST9046 over the 60 cell-line tumor panel. Accordingly, it was selected for a dose-response assay; a broad spectrum antiproliferative activity with GI(50) ranging from 1.3 to 3.9 µM was exerted. To explore a potential kinase inhibitory effect, KST9046 was applied at a single dose of 10 µM against a kinase panel of 347 different enzymes representing >50% of the predicted human protein kinome. Interestingly, selective inhibition of 76% was observed on DDR1 kinase. Further, KST9046 showed an IC(50) value of 4.38 µM for DDR1. A molecular docking model presented KST9046 as a potential type III inhibitor for DDR1 kinase with an allosteric mode of interaction, which may offer an explanation for its selectivity. As further investigation, CYP450 assay was carried out for KST9046, it showed a promising toxicity profile against four different isoforms. Based on these findings, KST9046 can be further evaluated as a promising safe new hit for the development of broad spectrum anticancer agents with a selectivity for DDR1 kinase.

Discovery of 2-aryloxy-4-amino-quinazoline derivatives as novel protease-activated receptor 2 (PAR2) antagonists.

Protease-activated receptor 2 (PAR2) is a member of G protein-coupled receptor and its activation initiates diverse inflammatory responses. Recent studies suggest that antagonists of PAR2 may provide a novel therapeutic strategy for inflammatory diseases. In this study, we have developed a series of 2-aryloxy-4-amino-quinazoline derivatives as PAR2 antagonists and examined their effects against LPS-induced inflammatory responses in RAW 264.7 macrophages. Among these derivatives, compound 2f displayed the greatest antagonistic activity with the IC50 value of 2.8µM. Binding modes of the newly identified PAR2 antagonists were analyzed by molecular docking using IFD/MM-GBSA methods in the putative binding site of PAR2 homology model. Moreover, 2f demonstrated significant inhibitory effects on the LPS-activated pro-inflammatory mediators including nitric oxide (NO), prostaglandin E2 (PGE2), interleukin-1ß (IL-1ß), interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) through the regulation of various intracellular signaling pathways involving nuclear factor-κB (NF-κB), activator protein 1 (AP-1) and the mitogen-activated protein kinases (MAPK). Furthermore, administration of 2f significantly reduced the mortality of LPS-induced sepsis in mice. These results provide useful insights into the development of novel PAR2 antagonists with anti-inflammatory activity in vitro and in vivo.

Design, synthesis, in-vitro antiproliferative activity and kinase profile of new picolinamide based 2-amido and ureido quinoline derivatives.

New 2-amido and ureido quinoline derivatives substituted with 2-N-methylamido-pyridin-4-yloxy group at the 5-position of quinoline (18 final compounds) have been designed and synthesized as anticancer sorafenib congeners. Among the synthesized derivatives, fourteen compounds were selected for evaluation of their antiproliferative activity over a panel of 60 cancer cell lines at a single dose concentration of 10 µM at National Cancer Institute (NCI, USA). Four compounds, 9b-d and 9f showed promising mean growth inhibitions and thus were further tested at five-dose testing mode to determine their IC50 values. The data revealed that 2,4-difluorophenyl (9b) and 4-chloro-3-trifluoromethylphenyl (9d) urea compounds are the most active derivatives with significant efficacies and superior potencies than sorafenib in 36 and 12 cancer cell lines, respectively, belonging particularly to renal carcinoma cell (RCC), ovarian, and non small cell lung cancer (NSCL). Compound 9b and 9d were found to be six and two times more potent than sorafenib against A498 RCC line, with IC50 values of 0.42 µM and 1.36 µM, respectively. Accordingly, compound 9d was screened over a panel of 41 oncogenic kinases at a single dose concentration of 10 µM to profile its kinase inhibitory activity. Interestingly, the compound showed highly selective inhibitory activities ( 81.8% and 96.3%) against BRAF(V600E) and C-RAF kinases with IC50 values of 316 nM and 61 nM, respectively. In addition, molecular docking, cell cycle analysis, compliance to Lipinski's rule of five, and in silico toxicity assessment have been reported.

ABL kinase inhibitory and antiproliferative activity of novel picolinamide based benzothiazoles.

A series of novel picolinamide based benzothiazoles (17 final compounds), targeting both wild-type and the most resistant T315I mutant of Bcr-Abl kinase, has been designed and synthesized. Moreover, a selected array (8 compounds) was evaluated for its antiproliferative activity over a panel of 60 cancer cell lines. Compound 5l was the most potent derivative against both native and T315I mutant ABL with IC50 values of 18.2 and 39.9nM, respectively, and showed highly selective inhibitory activity (89.8%) towards the Bcr-Abl dependent leukemia cell (K-562) at 10µM concentration. Significance of C6-oxypicolinamide moiety and SAR study for the C2 aliphatic side chain of benzothiazole are discussed in detail.