Daphnetin inhibits TNF‐α and VEGF‐induced angiogenesis through inhibition of the IKKs/IκBα/NF‐κB,Src/FAK/ERK1/2 and Akt signalling pathways

Coumarins, identified as plant secondary metabolites possess diverse biological activities including anti‐angiogenic properties. Daphnetin (DAP), a plant derived dihydroxylated derivative of coumarin has shown significant pharmacological properties such as anticancer, anti‐arthritic and anti‐inflammatory. The present study was performed to investigate the anti‐angiogenic potential of DAP, focusing on the mechanism of action. The in vivo anti‐angiogenic potential of DAP was evaluated by vascular endothelial growth factor (VEGF)‐induced rat aortic ring (RAR) assay and chick chorioallantoic membrane (CAM) assay. For in vitro evaluation, wounding migration, transwell invasion, tube formation and apoptosis assays were performed on VEGF (8 ng/mL)‐induced human umbilical vein endothelial cells (HUVECs). The cellular mechanism of DAP was examined on TNFα (10 ng/mL) and VEGF‐induced HUVECs by extracting the mRNA and protein levels using RT‐qPCR and western blotting. Our data demonstrated that DAP inhibited the in vivo angiogenesis in the RAR and CAM assay. DAP also inhibited the different steps of angiogenesis, such as migration, invasion, and tube formation in HUVECs. DAP inhibited nuclear factor‐κB signalling together including TNF‐α induced IκBα degradation; phosphorylation of IκB kinase (IKKα/β) and translocation of the NF‐κB‐p65 protein. Furthermore, western blotting revealed that DAP significantly down‐regulated the VEGF‐induced signalling such as c‐Src, FAK, ERK1/2 and the related phosphorylation of protein kinase B (Akt) and VEGFR2 expressions. DAP reduced the elevated mRNA expression of iNOS, MMP2 and also, induced apoptosis in VEGF‐stimulated HUVECs by the caspase‐3 dependent pathway. Taken together, this study reveals that DAP may have novel prospective as a new multi‐targeted medication for the anti‐angiogenesis and cancer therapy.     

Synthesis of Novel Pyrimidin‐4‐One Bearing Piperazine Ring‐Based Amides as Glycogen Synthase Kinase‐3β Inhibitors with Antidepressant Activity

Novel pyrimidin‐4‐one derivatives have been synthesized using EDC coupling and evaluated as glycogen synthase kinase‐3β (GSK‐3β) inhibitors. Among all the synthesized compounds, compound 5 (3‐methyl‐6‐phenyl‐2‐(piperazin‐1‐yl)‐3,4‐dihydropyrimidin‐4‐one) exhibited the most potent inhibitory activity against GSK‐3β with IC₅₀ value of 74 nm . The molecular docking studies were performed to elucidate the binding modes of the compounds with the target, and a crucial interaction involving hydrogen bond formation with Val‐135 to the active site of GSK‐3β was observed. Furthermore, the synthesized compounds were subjected to in vivo evaluation of their antidepressant activity, and compound 5 showing highest inhibition of GSK‐3β was also found to significantly reduce the duration of immobility at 50 mg/kg, when compared with fluoxetine, a known antidepressant drug. The results of our study suggest that compound 5 may serve as a valuable template for the design and development of inhibitors of GSK‐3β with antidepressant activity.     

Evaluation of Imidazole‐Based Compounds as Heme Oxygenase‐1 Inhibitors

Imidazole‐based compounds previously synthesized in our laboratory were selected and reconsidered as inhibitors of heme oxygenase‐1 obtained from the microsomal fractions of rat spleens. Most of tested compounds were good inhibitors with IC₅₀ values in the low micromolar range. Compounds were also assayed on membrane‐free full‐length recombinant human heme oxygenase‐1; all tested compounds were unable to interact with human heme oxygenase‐1 at 100 μm concentrations with the exception of compounds 11 and 13 that inhibited the enzyme of 54% and 20%, respectively. The binding of the most active compound 11 with heme or heme‐conjugated human heme oxygenase‐1 was also examined by spectral analyses. When heme was not conjugated to human heme oxygenase‐1, compound 11 caused changes in the heme spectrum only at concentration 50‐fold (100 μm ) higher than that required to inhibit rat heme oxygenase‐1; when heme was conjugated to human heme oxygenase‐1, compound 11 was able to form a heme‐compound 11 complex also at low micromolar concentrations. To obtain information on the binding mode of the tested compounds with enzyme, docking studies and pharmacophore analysis were performed. Template docking results were in agreement with experimental inhibition data and with a structure‐based pharmacophoric model. These data may be exploitable to design new OH‐1 inhibitors.     

Retracted: Long Non‐coding RNA Linc‐ITGB1 Knockdown Inhibits Cell Migration and Invasion in GBC‐SD/M and GBC‐SD Gallbladder Cancer Cell Lines

Gallbladder cancer is a highly aggressive malignancy with a low 5‐year survival rate. Despite advances in the molecular understanding of the initiation and progression in gallbladder cancer, treatment modalities such as surgery, radiotherapy, or chemotherapy in advanced cases did not yield promising outcomes. Therefore, it is of great importance to uncover new mechanism underlying gallbladder cancer growth and metastasis. In this study, we identified a differentially expressed long intergenic non‐coding RNA, linc‐ITGB1, in a pair of higher and lower metastatic gallbladder cancer cell sublines. Then, the potential role of linc‐ITGB1 in gallbladder cancer cell proliferation, migration, and invasion was explored using a lentivirus‐mediated RNA interference system. Functional analysis showed that knockdown of linc‐ITGB1 significantly inhibited gallbladder cancer cell proliferation. Moreover, cell migration and invasion were reduced by over twofold in linc‐ITGB1 knockdown cells probably due to upregulation of β‐catenin and downregulation of vimentin, slug, and TCF8. In conclusion, linc‐ITGB1 potentially promoted gallbladder cancer invasion and metastasis by accelerating the process of epithelial‐to‐mesenchymal transition, and the application of RNA interference targeting linc‐ITGB1 might be a potential form of gallbladder cancer treatment in advanced cases.     

Design,Synthesis and Biological Evaluation of 3,9‐diazatetraasteranes as Novel Matrilysin Inhibitors

Matrilysin is an ideal biological target to develop novel inhibitors because it is overexpressed in malignant tumour cells. A series of 3,9‐diazatetraasteranes was designed as inhibitors of matrilysin, which was an ideal biological target because it is responsible for aggressive malignant phenotypes and poor prognoses implicated in many cancers. Docking simulation supported the initial pharmacophore hypothesis and suggested a common interaction mechanism of 3,9‐diazatetraasteranes with the catalytic site of matrilysin. The 3,9‐diazatetraasteranes were synthesized by the photocyclization of 4‐aryl‐1,4‐dihydropyridines, and their structures were determined using ¹H NMR, ¹³C NMR and MS. The inhibitory activities of these compounds on matrilysin were investigated in vitro using an MTT assay in A549 (small cell lung cancer) cells. The results show that the 3,9‐diazatetraasteranes can inhibit the growth of A549 tumour cells. The best IC₅₀ value is approximately 50 μm . This result indicates that 3,9‐diazatetraasteranes will be useful pharmacological tools for the investigation of matrilysin inhibitors.     

Novel Quinazoline Derivatives Bearing Various 4‐Aniline Moieties as Potent EGFR Inhibitors with Enhanced Activity Against NSCLC Cell Lines

A class of novel quinazoline derivatives bearing various C‐4 aniline moieties was synthesized and biologically evaluated as potent epidermal growth factor receptor (EGFR) inhibitors for intervention of non‐small‐cell lung cancer (NSCLC). Most of these inhibitors are comparable to gefitinib in inhibiting these cancer cell lines, and several of them even displayed superior inhibitory activity. In particular, analogue 5b with an IC₅₀ of 0.10 μm against the EGFR wild‐type A431 cells and 5c with an IC₅₀ of 0.001 μm against the gefitinib‐sensitive HCC827 cells (EGFR del E746‐A750) was identified as highly active EGFR inhibitors. It was also significant that the discovered analogue 2f , not only has high potency against the gefitinib‐sensitive cells (IC₅₀ = 0.031 μm ), but also possesses remarkably improved activity against the gefitinib‐resistant cells. In addition, the enzymatic assays and the Western blot analysis for evaluating the effects of the typical inhibitors indicated that these molecules strongly interfere with the EGFR target.     

Synthesis,Biological Evaluation,and Molecular Simulation of Chalcones and Aurones as Selective MAO‐B Inhibitors

A series of chalcones and aurones were synthesized and evaluated in vitro as monoamine oxidase inhibitors (MAOi). Our results show that aurones, which had not been previously reported as MAOi, are MAO‐B inhibitors. Thus, both families inhibited selectively the B isoform of MAO in the micromolar range, offering novel scaffolds for the design of new and potent MAO inhibitors. The main structural requirements for their activity were characterized with the aid of 3D‐QSAR and docking studies.     

Synthesis and Evaluation of 3‐(furo[2,3‐b]pyridin‐3‐yl)‐4‐(1H‐indol‐3‐yl)‐maleimides as Novel GSK‐3β Inhibitors and Anti‐Ischemic Agents

A series of novel 3‐(furo[2,3‐b]pyridin‐3‐yl)‐4‐(1H‐indol‐3‐yl)‐maleimides were designed, synthesized, and biologically evaluated for their GSK‐3β inhibitory activities. Most compounds showed favorable inhibitory activities against GSK‐3β protein. Among them, compounds 5n , 5o , and 5p significantly reduced GSK‐3β substrate tau phosphorylation at Ser396 in primary neurons, indicating inhibition of cellular GSK‐3β activity. In the in vitro neuronal injury models, compounds 5n , 5o , and 5p prevented neuronal death against glutamate, oxygen–glucose deprivation, and nutrient serum deprivation which are closely associated with cerebral ischemic stroke. In the in vivo cerebral ischemia animal model, compound 5o reduced infarct size by 10% and improved the neurological deficit. The results may provide new insights into the development of novel GSK‐3β inhibitors with potential neuroprotective activity against brain ischemic stroke.     

N‐substituted Piperazinopyridylsteroid Derivatives as Abiraterone Analogues Inhibit Growth and Induce Pro‐apoptosis in Human Hormone‐independent Prostate Cancer Cell Lines

Nine new 17‐(piperazin‐1‐yl)pyridin‐5‐yl)steroids as abiraterone analogues were synthesized. Compounds 5d and 5g showed selective activities against 17α‐hydroxylase/C17,20‐lyase (CYP17A1) and aromatase (CYP19), respectively. IC₅₀ values of 5d were 5.09 and >50? μm , whereas these values for 5g were >50 ?μm and 7.40 μm , respectively, for CYP17A1 and CYP19. Molecular modelling highlighted that the inhibitor designed to bind cytochrome P450 haem iron is a necessary condition but not the only rationale to explain inhibitory activity. These abiraterone analogues were then evaluated on hormone‐independent prostate cancer cell lines DU‐145 and PC‐3 and on hormone‐dependent breast and prostate cancer cell lines MCF‐7 and LNCaP, respectively. Compounds 5e , 5g and 5i have showed potent activities only on hormone‐independent prostate cancer cell lines DU‐145 and PC‐3 with 60–85% inhibition of both cell viability and growth at 10 nm with pro‐apoptotic mechanism as illustrated in PC‐3 cells by DNA ladder assay and Western blotting of Bax, Casp‐3 and its substrate, the poly (ADP–ribose) polymerase. We conclude that hybrid heterocycle steroids could be good lead compounds in the drug design especially against hormone‐independent prostate cancer.     

Repurposing Human PDE4 Inhibitors for Neglected Tropical Diseases. Evaluation of Analogs of the Human PDE4 Inhibitor GSK‐256066 as Inhibitors of PDEB1 of Trypanosoma brucei

Cyclic nucleotide phosphodiesterases (PDEs) have been identified as important enzyme targets for drug development in both humans and Trypanosoma brucei, the causative agent of human African trypanosomiasis. With this in mind, we recently reported the profiling of a range of human phosphodiesterase inhibitors, showing that human PDE4 inhibitors tend to display the best potency against the trypanosomal phosphodiesterase TbrPDEB1. Among these was GSK‐256066, a potent inhibitor of human PDE4 and a weak inhibitor of TbrPDEB1. In this report, we describe the results of a structure–activity relationship study of this chemotype, leading to the discovery of analogs with improved potency against TbrPDEB1 and micromolar inhibition of T. brucei cellular growth. We rationalize the potency trends via molecular docking of the new inhibitors into a recently reported apo structure of TbrPDEB1. The studies in this article will inform future efforts in repurposing human PDE inhibitors as antitrypanosomal agents.     

Knockdown of GPR137,G Protein‐coupled receptor 137, Inhibits the Proliferation and Migration of Human Prostate Cancer Cells

GPR137 belongs to the G protein‐coupled receptor family involving the regulation of transmembrane signal transduction that launches pivotal cellular functions. However, its function in prostate cancer (PCa) has been rarely reported. It was found in this study that GPR137 was upregulated in PCa tissues as compared with that in paracancerous tissues. To see whether GPR137 could serve as a potential therapeutic target for PCa, GPR137 was knocked down to verify its biological function in PCa cells. Lentivirus‐introduced short hairpin RNA (shRNA) was designed to silence GPR137 gene. It was found that silencing of GPR137 gene suppressed the proliferation and colony formation of PCa cell lines PC‐3 and DU145. Further study indicated that growth inhibition by GPR137 knockdown was associated with cell cycle arrest at G0/G1 phase. Furthermore, silencing of GPR137 repressed the invasion and migration abilities of PC‐3 cells via downregulating slug and snail and upregulating E‐cadherin. Collectively, these findings imply that GPR137 plays an important role in the occurrence and progression of PCa and may prove to be a potential therapeutic target for the treatment of advanced PCa.     

Preparation and Evaluation of 99mTc‐labeled anti‐CD11b Antibody Targeting Inflammatory Microenvironment for Colon Cancer Imaging

CD11b, an active constituent of innate immune response highly expressed in myeloid‐derived suppressor cells (MDSCs), can be used as a marker of inflammatory microenvironment, particularly in tumor tissues. In this research, we aimed to fabricate a ^99mTc‐labeled anti‐CD11b antibody as a probe for CD11b⁺ myeloid cells in colon cancer imaging with single‐photon emission computed tomography (SPECT). In situ murine colon tumor model was established in histidine decarboxylase knockout (Hdc^?/?) mice by chemicals induction. ^99mTc‐labeled anti‐CD11b was obtained with labeling yields of over 30% and radiochemical purity of over 95%. Micro‐SPECT/CT scans were performed at 6 h post injection to investigate biodistributions and targeting of the probe. In situ colonic neoplasma as small as 3 mm diameters was clearly identified by imaging; after dissection of the animal, anti‐CD11b immunofluorescence staining was performed to identify infiltration of CD11b+ MDSCs in microenvironment of colonic neoplasms. In addition, the images displayed intense signal from bone marrow and spleen, which indicated the origin and migration of CD11b⁺ MDSCs in vivo, and these results were further proved by flow cytometry analysis. Therefore, ^99mTc‐labeled anti‐CD11b SPECT displayed the potential to facilitate the diagnosis of colon tumor in very early stage via detection of inflammatory microenvironment.     

Synthesis,Biological Evaluation,and Docking of Dihydropyrazole Sulfonamide Containing 2‐hydroxyphenyl Moiety: A Series of Novel MMP‐2 Inhibitors

In this study, we synthesized a series of dihydropyrazole sulfonamide derivatives containing 2‐hydroxyphenyl moiety as antitumor agents to target the matrix metalloproteinase‐2 (MMP‐2). All of the synthesized compounds were examined by bioactivity assays, in which compound 4c turned out as a potential antagonist of MMP‐2 along with potent anticancer activity against four tumor cell lines. Structure–activity relationship analysis was also performed to examine how structural changes impacted the bioactivity. Suggested to be caused by the induction of apoptosis, the antitumor mechanism of 4c was further confirmed by PI combining with annexin V‐FITC staining assay using flow cytometry analysis. These new findings along with molecular docking observations suggested that compound 4c could be developed as a potential anticancer agent.     

Synthesis and Quantitative Structure‐activity Relationships Study for Arylpropenamide Derivatives as Inhibitors of Hepatitis B Virus Replication

A series of new arylpropenamide derivatives containing different aryl groups were synthesized, characterized, and evaluated for their anti‐hepatitis B virus (HBV) activities. A new high accuracy QSAR model of arylpropenamide was constructed based on a more completely activities data and calculation parameter. The 2D‐QSAR equations, by using DFT and multiple linear regression analysis methods, revealed that higher value of thermal energy (TE) and lower entropy (S^?) increase the anti‐HBV activities of the arylpropenamide molecules. Predictive 3D‐QSAR models were established by SYBYL multifit molecular alignment rule. The optimum models were all statistically significant with cross‐validated and conventional coefficients, indicating that they were reliable enough for activity prediction.     

Design,Synthesis, and Biological Evaluation of Novel Quinazoline Derivatives as Anti‐inflammatory Agents against Lipopolysaccharide‐induced Acute Lung Injury in Rats

Quinazoline has been reported to exhibit multiple bioactivities. The aim of this study was to discover new quinazoline derivatives with preventive effect on lipopolysaccharide‐induced acute lung injury via anti‐inflammatory actions. Thirty‐three 4‐amino quinazolin derivatives were synthesized and screened for anti‐inflammatory activities in lipopolysaccharide‐induced macrophages. The most potent four compounds, 6h, 6m, 6p , and 6q , were shown dose‐dependent inhibition against lipopolysaccharide‐induced TNF‐α and IL‐6 release. Then, the preliminary structure–activity relationship and quantitative structure–activity relationship analyses were conducted. To further determine the effects of quinazolines on acute lung injury treatment, lipopolysaccharide‐induced acute lung injury model was employed. Male Sprague Dawley rats were pretreated with 6m or 6q before instillation of lipopolysaccharide. The results showed that 6m and 6q, especially 6q , obviously alleviated lung histopathological changes, inflammatory cells infiltration, and cytokines mRNA expression initiated by lipopolysaccharide. Taken together, this work suggests that 6m and 6q suppressed the lipopolysaccharide‐induced acute lung injury through inhibition of the inflammatory response in vivo and in vitro, indicating that quinazolines might serve as potential agents for the treatment of acute lung injury and deserve the continuing drug development and research.