Fadraciclib (CYC065) is a second-generation aminopurine CDK2/9 inhibitor with increased potency and selectivity toward CDK2 and CDK9 compared to seliciclib (R-roscovitine). In chronic lymphocytic leukemia (CLL), a disease that depends on the over-expression of anti-apoptotic proteins for its survival, inhibition of CDK9 by fadraciclib reduced phosphorylation of the C-terminal domain of RNA polymerase II and blocked transcription in vitro; these actions depleted the intrinsically short-lived anti-apoptotic protein Mcl-1 and induced apoptosis. While the simulated bone marrow and lymph node microenvironments induced Mcl-1 expression and protected CLL cells from apoptosis, these conditions did not prolong the turnover rate of Mcl-1, and fadraciclib efficiently abrogated the protective effect.
View Article and Find Full Text PDFOver the last 50 years, there has been a steady improvement in the treatment outcome of acute myeloid leukemia (AML). However, median survival in the elderly is still poor due to intolerance to intensive chemotherapy and higher numbers of patients with adverse cytogenetics. Fadraciclib (CYC065), a novel cyclin-dependent kinase (CDK) 2/9 inhibitor, has preclinical efficacy in AML.
View Article and Find Full Text PDFThe Tanacetum genus is a big treasure with the presence of biologically-active compounds and members of this genus are widely used for the treatment of several diseases in traditional medicine system. Considering this fact, we aimed to analyze the extracts from Tanacetum vulgare L. in case of chemical profiles and biological effects.
View Article and Find Full Text PDFThe acetylcholinesterase (AChE) inhibitors are the main drugs for symptomatic treatment of neurodegenerative disorders like Alzheimer's disease. A recently designed, synthesized and tested hybrid compound between the AChE inhibitor galantamine (GAL) and the antioxidant polyphenol curcumin (CU) showed high AChE inhibition in vitro. Here, we describe tests for acute and short-term toxicity in mice as well as antioxidant tests on brain homogenates measured the levels of malondialdehide (MDA) and glutathione (GSH) and in vitro DPPH, ABTS, FRAP and LPO inhibition assays.
View Article and Find Full Text PDFThe undruggable nature of oncogenic Myc transcription factors poses a therapeutic challenge in neuroblastoma, a pediatric cancer in which MYCN amplification is strongly associated with unfavorable outcome. Here, we show that CYC065 (fadraciclib), a clinical inhibitor of CDK9 and CDK2, selectively targeted MYCN-amplified neuroblastoma via multiple mechanisms. CDK9 - a component of the transcription elongation complex P-TEFb - bound to the MYCN-amplicon superenhancer, and its inhibition resulted in selective loss of nascent MYCN transcription.
View Article and Find Full Text PDFGalantamine (GAL) and curcumin (CU) are alkaloids used to improve symptomatically neurodegenerative conditions like Alzheimer's disease (AD). GAL acts mainly as an inhibitor of the enzyme acetylcholinesterase (AChE). CU binds to amyloid-beta (Aβ) oligomers and inhibits the formation of Aβ plaques.
View Article and Find Full Text PDFCyclin-dependent kinases (CDKs) contribute to the cancer hallmarks of uncontrolled proliferation and increased survival. As a result, over the last two decades substantial efforts have been directed towards identification and development of pharmaceutical CDK inhibitors. Insights into the biological consequences of CDK inhibition in specific tumor types have led to the successful development of CDK4/6 inhibitors as treatments for certain types of breast cancer.
View Article and Find Full Text PDFGlioblastoma (GBM) is the most common primary brain tumor with no available cure. As previously described, seliciclib, a first-generation cyclin-dependent kinase (CDK) inhibitor, down-regulates the anti-apoptotic protein, Mcl-1, in GBM, thereby sensitizing GBM cells to the apoptosis-inducing effects of the death receptor ligand, tumor necrosis factor-related apoptosis-inducing ligand (TRAIL). Here, we have assessed the efficacy of seliciclib when delivered in combination with the antibody against human death receptor 5, drozitumab, in clinically relevant patient-derived xenograft (PDX) models of GBM.
View Article and Find Full Text PDFTo date, reconstitution of one of the fundamental methods of cell communication, the signaling pathway, has been unaddressed in the bottom-up construction of artificial cells (ACs). Such developments are needed to increase the functionality and biomimicry of ACs, accelerating their translation and application in biotechnology. Here, we report the construction of a de novo synthetic signaling pathway in microscale nested vesicles.
View Article and Find Full Text PDFThe enzyme acetylcholinesterase is a key target in the treatment of Alzheimer's disease because of its ability to hydrolyze acetylcholine via the catalytic binding site and to accelerate the aggregation of amyloid-β peptide via the peripheral anionic site (PAS). Using docking-based predictions, in the present study we design 20 novel galantamine derivatives with alkylamide spacers of different length ending with aromatic fragments. The galantamine moiety blocks the catalytic site, while the terminal aromatic fragments bind in PAS.
View Article and Find Full Text PDFThe quest to develop novel antimitotic chemotherapy agents has led to the generation of several small molecule inhibitors targeting Plk1, a protein kinase required for multiple aspects of cell division. Previous studies have shown that upon exposure to Plk1 inhibitors, cells enter mitosis, delay briefly in prophase and then arrest in mitosis due to an inability to undergo centrosome separation. Here, we show that four different classes of Plk1 inhibitor block mitotic entry in several cancer cell lines and non-transformed RPE-1 cells.
View Article and Find Full Text PDFThe inhibitors of acetylcholinesterase are the main therapy against Alzheimer's disease. Among them, galantamine is the best tolerated and the most prescribed drug. In the present study, 41 galantamine derivatives with known acetylcholinesterase inhibitory activities expressed as IC50 were selected from the literature and docked into a recombinant human acetylcholinesterase by GOLD.
View Article and Find Full Text PDFWe report a case of a 30-year-old woman with discoid lupus erythematosus (DLE) involving only a single lower eyelid. The diagnostic delay is explained by the unspecific clinical and histopathology picture and lack of specific changes in the first biopsy specimen taken. The diagnosis was based on later histological and immunological studies.
View Article and Find Full Text PDFBackground: Amplification of aurora kinase A (AK-A) overrides the mitotic spindle assembly checkpoint, inducing resistance to taxanes. RNA interference targeting AK-A in human pancreatic cancer cell lines enhanced taxane chemosensitivity. In this study, a novel AK-A inhibitor, CYC3, was investigated in pancreatic cancer cell lines, in combination with paclitaxel.
View Article and Find Full Text PDFThe Aurora kinases (serine/threonine kinases) were discovered in 1995 during studies of mutant alleles associated with abnormal spindle pole formation in Drosophila melanogaster. They soon became the focus of much attention because of their importance in human biology and association with cancer. Aurora kinases are essential for cell division and are primarily active during mitosis.
View Article and Find Full Text PDFAurora A kinase is a key regulator of mitosis, which is upregulated in several human cancers, making it a potential target for anticancer therapeutics. Consequently, robust medium- to high-throughput cell-based assays to measure Aurora A kinase activity are critical for the development of small-molecule inhibitors. Here the authors compare measurement of the phosphorylation of two Aurora A substrates previously used in high-content screening Aurora A assays, Aurora A itself and TACC3, with a novel substrate Lats2.
View Article and Find Full Text PDFThe main difficulty in the development of ATP antagonist kinase inhibitors is target specificity, since the ATP-binding motif is present in many proteins. We introduce a strategy that has allowed us to identify compounds from a kinase inhibitor library that block the cyclin-dependent kinases responsible for regulating transcription, i.e.
View Article and Find Full Text PDFJ Pharmacokinet Pharmacodyn
August 2010
The spindle assembly checkpoint is a cell cycle surveillance mechanism that ensures the proper separation of chromosomes prior to cell division at mitosis. Aurora kinases play critical roles in mitotic progression and hence small-molecule inhibitors of Aurora kinases have been developed as a new class of potential anti-cancer drugs. In this paper we present for the first time an integrated pharmacokinetic-pharmacodynamic model of the functional effects of CYC116 (a known inhibitor of Aurora kinases A and B) on the spindle assembly checkpoint.
View Article and Find Full Text PDFThrough cell-based screening of our kinase-directed compound collection, we discovered that a subset of N-phenyl-4-(thiazol-5-yl)pyrimidin-2-amines were potent cytotoxic agents against cancer cell lines, suppressed mitotic histone H3 phosphorylation, and caused aberrant mitotic phenotypes. It was subsequently established that these compounds were in fact potent inhibitors of aurora A and B kinases. It was shown that potency and selectivity of aurora kinase inhibition correlated with the presence of a substituent at the aniline para-position in these compounds.
View Article and Find Full Text PDFFollowing the recent discovery and development of 2-anilino-4-(thiazol-5-yl)pyrimidine cyclin dependent kinase (CDK) inhibitors, a program was initiated to evaluate related ring-constrained analogues, specifically, 2-methyl- and 2-amino-N-aryl-4,5-dihydrothiazolo[4,5-h]quinazolin-8-amines for inhibition of CDKs. Here we report the rational design, synthesis, structure-activity relationships (SARs), and cellular mode-of-action profile of these second generation CDK inhibitors. Many of the analogues from this chemical series inhibit CDKs with very low nanomolar K(i) values.
View Article and Find Full Text PDFBiomed Pap Med Fac Univ Palacky Olomouc Czech Repub
June 2008
Background: Aurora kinases are a recently discovered family of kinases (A, B & C) consisting of highly conserved serine\threonine protein kinases found to be involved in multiple mitotic events: regulation of spindle assembly checkpoint pathway, function of centrosomes and cytoskeleton, and cytokinesis. Aberrant expression of Aurora kinases may lead to cancer. For this reason the Aurora kinases are potential targets in the treatment of cancer.
View Article and Find Full Text PDFThe renewed interest in an enzyme first discovered over 25 years ago stems from the potential of inhibitors of this enzyme to treat conditions as diverse as diabetes, Alzheimer's disease, stroke and bipolar disorder, and even to enhance the repopulating capacity of transplanted haematopoietic stem cells. The emergence of the first few potent and specific glycogen synthase kinase-3 (GSK-3) inhibitors will end years of speculation on their potential and finally allow the impact of GSK-3 inhibitors to be evaluated clinically. The next few years are likely to be particularly exciting ones for fans of this old enzyme.
View Article and Find Full Text PDFCritical to the inhibitory action of the oncogene product, MDM2, on the tumour suppressor, p53, is association of the N-terminal domain of MDM2 (MDM2N) with the transactivation domain of p53. The structure of MDM2N was previously solved with a p53-derived peptide, or small-molecule ligands, occupying its binding cleft, but no structure of the non-liganded MDM2N (i.e.
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