piperidines and thiazolyl-blue

Mutations of the type III receptor tyrosine kinase FLT3 occur in approximately 30% of acute myeloid leukemia patients and lead to constitutive activation. This has made FLT3-activating mutations an attractive drug target because they are probable driver mutations of this disease. As more potent FLT3 inhibitors are developed, a predictable development of resistance-conferring point mutations, commonly at residue D835, has been observed. Crenolanib is a highly selective and potent FLT3 tyrosine kinase inhibitor (TKI) with activity against the internal tandem duplication (FLT3/ITD) mutants and the FLT3/D835 point mutants. We tested crenolanib against a panel of D835 mutant cell lines and primary patient blasts and observed superior cytotoxic effects when compared with other available FLT3 TKIs such as quizartinib and sorafenib. Another potential advantage of crenolanib is its reduced inhibition of c-Kit compared with quizartinib. In progenitor cell assays, crenolanib was less disruptive of erythroid colony growth, which may result in relatively less myelosuppression than quizartinib. Finally, correlative data from an ongoing clinical trial demonstrate that acute myeloid leukemia patients can achieve sufficient levels of crenolanib to inhibit both FLT3/ITD and resistance-conferring FLT3/D835 mutants in vivo. Crenolanib is thus an important next-generation FLT3 TKI.

Topics: Antineoplastic Agents; Benzimidazoles; Bone Marrow; Bone Marrow Cells; Colony-Forming Units Assay; Drug Resistance, Neoplasm; fms-Like Tyrosine Kinase 3; HL-60 Cells; Humans; Leukemia, Myeloid, Acute; Piperidines; Point Mutation; Prognosis; Proto-Oncogene Proteins c-kit; Sequence Analysis, DNA; Tetrazolium Salts; Thiazoles; Time Factors

To examine the anti-proliferative effect of the combination of docetaxel, the cornerstone of modern chemotherapy for prostate cancer, and vandetanib, a potent inhibitor of VEGFR-2 tyrosine kinase, applied to the representative hormone-refractory human prostate cancer cell line PC3. The aim is to analyze if a supra-additive/synergic effect of the combined treatment on cell viability exists and to understand the molecular key-factors involved. We first hypothesized an effect of vandetanib in modulation the function of MDR1, leading to a longer retention of docetaxel inside the cell. It may also be possible that vandetanib could modulate the docetaxel-induced changes in expression of prosurvival and proapoptotic proteins, leading to a positive balance forward cell death.. We used PC3 cells either wild type (PC3wt) or with acquired resistance to docetaxel (PC3R), characterized by a higher expression of MDR1. We studied both mRNA and protein, the expression of EGF and VEGF receptors at a basal level and after each treatment, as well as the expression of cell cycle and apoptosis related genes.. Cell proliferation data suggested a supra-additive cytotoxic effect of the combination of docetaxel plus vandetanib, when given together or with the sequence vandetanib followed by docetaxel. We did not observe any effect of vandetanib on MDR1, in the PC3R cell lines, characterized by a higher pump expression than PC3wt. On the other side, we defined a number of key factors involved in the pro- and anti-survival balance, which regulation, by single drugs and/or by combined treatment, could explain the effect on cell cytotoxicity; also where there are apparently contradictory results.. Our data suggest that combined treatment with vandetanib and docetaxel alters the balance of proapoptotic and prosurvival proteins, ultimately leading to potentiation of docetaxel-induced apoptosis in human prostate cancer cells in vitro, irrespective of cells being sensitive or resistant to docetaxel.

Topics: Antineoplastic Combined Chemotherapy Protocols; Apoptosis; ATP Binding Cassette Transporter, Subfamily B; ATP Binding Cassette Transporter, Subfamily B, Member 1; Cell Cycle; Cell Line, Tumor; Cell Proliferation; Cell Survival; Coloring Agents; Docetaxel; Dose-Response Relationship, Drug; Drug Resistance, Neoplasm; ErbB Receptors; Gene Expression Regulation, Neoplastic; Humans; Male; Piperidines; Prostatic Neoplasms, Castration-Resistant; Quinazolines; Taxoids; Tetrazolium Salts; Thiazoles; Vascular Endothelial Growth Factor Receptor-2

Poly(ADP-ribose) polymerases (PARPs) are recognized as key regulators of cell survival or death. PARP-1 is essential to the repair of DNA single-strand breaks via the base excision repair pathway. The enzyme may be overactivated in response to inflammatory cues, thus depleting cellular energy pools and eventually causing cell death. Accordingly, PARP-1 inhibitors, acting by competing with its physiological substrate NAD(+), have been proposed to play a protective role in a wide range of inflammatory and ischemia/reperfusion-associated diseases. Recently, it has also been reported that PARP-1 regulates proinflammatory mediators, including cytokines, chemokines, adhesion molecules, and enzymes (e.g., iNOS). Furthermore, PARP-1 has been shown to act as a coactivator of NF-κB- and other transcription factors implicated in stress/inflammation, as AP-1, Oct-1, SP-1, HIF, and Stat-1. To further substantiate this hypothesis, we tested the biomolecular effects of PARP-1 inhibitors DPQ and PJ-34 on human glioblastoma cells, induced to a proinflammatory state with lipopolysaccharide and Interferon-γ. PARP-1 expression was evaluated by laser scanning confocal microscopy immunofluorescence (LSM); nitrite production, LDH release and cell viability were also determined. LSM of A-172, SNB-19 and CAS-1 cells demonstrated that DPQ and PJ-34 downregulate PARP-1 expression; they also cause a decrease of LDH release and nitrite production, while increasing cell viability. Similar effects were caused in all three cell lines by N-mono-methyl-arginine, a well known iNOS inhibitor, and by L-carnosine and trehalose, two antioxidant molecules. These results demonstrate that, similar to other well characterized drugs, DPQ and PJ-34 reduce cell inflammation and damage that follow PARP-1 overexpression, while they increase cell survival: this suggests their potential exploitation in clinical Medicine.

Topics: Anti-Inflammatory Agents; Biomarkers; Brain Neoplasms; Carnosine; Cell Line, Tumor; Cell Survival; Coloring Agents; Down-Regulation; Fluorescent Antibody Technique; Glioblastoma; Humans; Isoquinolines; L-Lactate Dehydrogenase; Microscopy, Confocal; Nitrites; Phenanthrenes; Piperidines; Poly (ADP-Ribose) Polymerase-1; Poly(ADP-ribose) Polymerase Inhibitors; Tetrazolium Salts; Thiazoles; Trehalose

Virosecurinine, the major alkaloid isolated from Securinega suffruticosa Pall Rehd was found to exhibit growth inhibition and cytotoxicity against huaman colon cancer SW480 cells via the microculture tetrazolium (MTT) assay. Due to its greater cytotoxic potency and selectivity towards SW480 cells, flow cytometry was used to analyze the cell cycle distribution of control and treated SW480 cells whereas Annexin V-FITC/PI flow cytometry analysis was carried out to confirm apoptosis induced by virosecurinine in SW480 cells. Apoptotic regulatory genes were determined by RT-PCR analysis. Virosecurinine was found to induce G1/S cell cycle arrest which led to predominantly apoptotic mode of cell death. Mechanistically, virosecurinine was found to up-regulated the Bax gene expression and down-regulated the Bcl-2 expression in SW480, The ratio of Bcl-2 to Bax was significantly decreased. Hence, we suggest that virosecurinine induced apoptosis in SW480 cells by affecting the expression of bcl-2 and bax.

Topics: Actins; Alkaloids; Antineoplastic Agents, Phytogenic; Apoptosis; Azepines; bcl-2-Associated X Protein; Cell Cycle; Cell Line, Tumor; Cell Survival; Colonic Neoplasms; Coloring Agents; Euphorbiaceae; Gene Expression; Humans; Lactones; Piperidines; Proto-Oncogene Proteins c-bcl-2; Real-Time Polymerase Chain Reaction; Tetrazolium Salts; Thiazoles

Ultraviolet light absorber (UVA) and hindered amine light stabilizer (HALS) retard sun-induced pigment degradation in silicone elastomeric maxillofacial prostheses. HALS inhibits polymer degradation and UVA dissipates UV radiation. Their effects on oral cells are unknown.. The purpose of this study was to evaluate the effects of UVA and HALS on membrane integrity, viability, and proliferation of human gingival fibroblasts and epithelial cells.. Tinuvin 123 (HALS) and Tinuvin 213 (UVA) were assessed for cytotoxicity, individually and in a 1:1 ratio (used in elastomers; HALS/UVA). The cells were exposed to HALS, UVA, or HALS/UVA (or control media containing only the diluent), and colorimetric assays measured membrane damage, viability, and proliferation. The data (% cytotoxicity or % control) were analyzed using 3-way cross-classified fixed effects ANOVA (alpha=.05).. HALS did not negatively affect either cell type. UVA or HALS/UVA (>or= approximately 0.004%) decreased viability by >or=90% in both cell lines; lower concentrations decreased activity in epithelial cells while increasing it in fibroblasts. UVA or HALS/UVA damaged membranes of both cell lines, but epithelial cells were more resistant. UVA or HALS/UVA inhibited proliferation of both cell types similarly. There was a slight synergistic effect of HALS and UVA on membrane damage in both cell lines, but generally not on other parameters.. Although it is unknown if HALS or UVA leaches from silicone elastomers in vivo, these data suggest that relative resistance of epithelial cells to UVA-induced membrane damage, and UVA's stimulation of fibroblast viability at some concentrations, might provide some protective effect.

Topics: Cell Line; Cell Membrane; Cell Proliferation; Cell Survival; Colorimetry; Coloring Agents; Decanoic Acids; Epithelial Cells; Fibroblasts; Gingiva; Humans; L-Lactate Dehydrogenase; Materials Testing; Maxillofacial Prosthesis; Piperidines; Silicone Elastomers; Spectrophotometry; Tetrazolium Salts; Thiazoles; Time Factors; Triazoles

In this study, we investigated the antidepressant-like effect of piperine in mice exposed to chronic mild stress (CMS) procedure. Repeated administration of piperine for 14 days at the doses of 2.5, 5 and 10 mg/kg reversed the CMS-induced changes in sucrose consumption, plasma corticosterone level and open field activity. Furthermore, the decreased proliferation of hippocampal progenitor cells was ameliorated and the level of brain-derived neurotrophic factor (BDNF) in hippocampus of CMS stressed mice was up-regulated by piperine treatment in the same time course. In addition, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and lactic dehydrogenase (LDH) assays showed that piperine (6.25-25 microM) or fluoxetine (FLU, 1 microM) dose-dependently protected primary cultured hippocampal neurons from the lesion induced by 10 microM corticosterone (CORT). Reverse transcription-polymerase chain reaction (RT-PCR) was used to detect the messenger ribonucleic acid (mRNA) level of BDNF in cultured neurons. Treatment with piperine (6.25-25 microM) for 72 h reversed the CORT-induced reduction of BDNF mRNA expression in cultured hippocampal neurons. In summary, up-regulation of the progenitor cell proliferation of hippocampus and cytoprotective activity might be mechanisms involved in the antidepressant-like effect of piperine, which may be closely related to the elevation of hippocampal BDNF level.

Topics: Alkaloids; Animals; Antidepressive Agents; Benzodioxoles; Brain-Derived Neurotrophic Factor; Cell Proliferation; Cell Survival; Cells, Cultured; Chronic Disease; Corticosterone; Depression; Hippocampus; Immunohistochemistry; L-Lactate Dehydrogenase; Male; Mice; Neurons; Piperidines; Polyunsaturated Alkamides; Rats; Rats, Sprague-Dawley; Reverse Transcriptase Polymerase Chain Reaction; Stem Cells; Stress, Psychological; Tetrazolium Salts; Thiazoles; Weight Gain

The neuroprotective effects of Delta(9)-tetrahydrocannabinol (THC) were examined using an in vitro model in which the AF5 CNS cell line was exposed to toxic levels of N-methyl-d-aspartate (NMDA), an agonist of the NMDA glutamate receptor. NMDA toxicity was reduced by THC, but not by the more specific cannabinoid receptor agonist, WIN55,212-2. Addition of dibutyryl cAMP (dbcAMP) to the culture medium did not alter the neuroprotective effect of THC and did not unmask a neuroprotective effect of WIN55,212-2. The cannabinoid antagonist SR141716A did not inhibit the neuroprotection induced by THC or alter the response to WIN55,212-2, even in the presence of dbcAMP, indicating that the neuroprotective effect of THC was cannabinoid receptor-independent. On the other hand, both THC and WIN55,212-2 produced cellular toxicology at higher dosages, an effect which was blocked in part by SR141716A. Capsaicin, an antioxidant and vanilloid receptor agonist, also produced a protective effect against NMDA toxicology. The protective effect of capsaicin was blocked by co-application of ruthenium red, but was not blocked by the specific vanilloid receptor antagonist capsazepine, and the transient receptor potential vanilloid type 1 (TRPV1) and ANKTM1 transcripts were not detected in AF5 cells. Thus, the neuroprotective effects of THC and capsaicin did not appear to be mediated by TRP ion channel family receptors. The antioxidant alpha-tocopherol prevented neurotoxicity in a dose-dependent manner. Therefore, THC may function as an antioxidant to increase cell survival in NMDA-induced neurotoxicity in the AF5 cell model, while higher dosages produce toxicity mediated by CB1 receptor stimulation.

Topics: alpha-Tocopherol; Animals; Benzimidazoles; Benzoxazines; Blotting, Northern; Blotting, Western; Calcium Channel Blockers; Calcium Channels; Capsaicin; Cell Count; Cell Death; Cell Lineage; Dizocilpine Maleate; DNA, Single-Stranded; Dose-Response Relationship, Drug; Dronabinol; Drug Interactions; Excitatory Amino Acid Agonists; Immunohistochemistry; In Situ Nick-End Labeling; Morpholines; N-Methylaspartate; Naphthalenes; Neurons; Neuroprotective Agents; Piperidines; Pyrazoles; Rats; Receptor, Cannabinoid, CB1; Receptors, N-Methyl-D-Aspartate; Reverse Transcriptase Polymerase Chain Reaction; Rimonabant; RNA, Messenger; Ruthenium; Tetrazolium Salts; Thiazoles; TRPC Cation Channels

Neuroblastoma is the most common extracranial solid tumor of children that arises from the sympathetic nervous system. Survival rates for neuroblastoma patients is low despite intensive therapeutic intervention, and the identification of new effective drugs remains a primary goal. The cyclin-dependent kinase inhibitor, flavopiridol, has demonstrated growth-inhibitory and cytotoxic activity against various tumor types. Our aim was to investigate flavopiridol effects on advanced-stage, N-myc proto-oncogene (MYCN)-amplified human neuroblastomas and the modulation of its activity by hypoxia, a critical determinant of tumor progression and a major challenge of therapy.. Cell viability was monitored by 3-(4,5 dimethyl-2 thiazolyl)-2,5 diphenyl-2H tetrazolium bromide (MTT) and trypan blue dye exclusion assays; DNA synthesis was assessed with the bromodeoxyuridine pulse-labeling technique; apoptosis was studied by Giemsa staining, DNA fragmentation, terminal deoxynucleotidyl-transferase-mediated dUTP nick end labeling reaction, flow cytometric determination of hypodiploid DNA content, and evaluation of caspase activity and cytochrome c (CytC) release; MYCN expression was determined by Northern and Western blotting.. Flavopiridol caused dose- and time-dependent decreases in neuroblastoma viability by inducing apoptosis, as confirmed by morphologic and biochemical criteria. Cell death was preceded by DNA synthesis inhibition and G1-G2 arrest, reversed by the pancaspase inhibitor, zVAD-fmk, and associated with caspase-3 and -2 activation and CytC increase. Moreover, flavopiridol strongly down-regulated MYCN mRNA and protein expression. Exposure to hypoxia enhanced both the extent of apoptosis and flavopiridol effects on CytC, caspase 3, and MYCN.. These results indicate that flavopiridol has growth-inhibitory and apoptotic activity against advanced-stage neuroblastomas in vitro and is worthy of further investigation for the treatment of this disease.

Topics: Apoptosis; Bromodeoxyuridine; Caspases; Cell Hypoxia; Cell Survival; Cyclin-Dependent Kinases; Cytochromes c; DNA; Down-Regulation; Enzyme Activation; Enzyme Inhibitors; Flavonoids; G1 Phase; G2 Phase; Genes, myc; Growth Inhibitors; Humans; Hypoxia; In Situ Nick-End Labeling; Neuroblastoma; Piperidines; Proto-Oncogene Mas; Tetrazolium Salts; Thiazoles; Tumor Cells, Cultured

Accumulating evidence indicates that small cell lung cancer (SCLC) is defective in many of the regulatory mechanisms that control cell cycle progression. The purpose of this study was to determine the effects of flavopiridol, a pan-cyclin-dependent kinase inhibitor, on growth and apoptosis of SCLC cell lines.. Cell growth was monitored using 3-(4,5dimethylthiazol-2yl)-2,5-diphenyl-tetrazolium bromide (MTT) and clonogenic assays. Induction of apoptosis was assessed using multiple assays, including flow cytometric determination of DNA content and mitochondrial membrane potential, terminal deoxynucleotide transferase-mediated dUTP nick end labeling (TUNEL), and Western blot analysis of procaspase 3 and poly(ADP-ribose) polymerase cleavage.. Flavopiridol induced growth inhibition and cytotoxicity in multiple SCLC cell lines, with an IC(50) of 50-100 nM and an LD(50) of 150-200 nM in 72-h MTT assays. The cytotoxicity seen in the MTT assay proved to be apoptosis by several criteria. Interestingly, inhibition of caspase activation with the caspase inhibitor Boc-Asp(OMe)-CH(2)F reduced TUNEL labeling by 40% but did not have any effect on the loss of mitochondrial membrane potential (detected as early as 4 h after drug exposure) or cytotoxicity in MTT assays. These results suggest that the primary event in flavopiridol-induced apoptosis involves induction of mitochondrial dysfunction. Cells synchronized with aphidicolin at the G(1)-S border and treated with flavopiridol during S phase showed a marked increase in apoptosis compared with an asynchronous population or a population treated during G(2)-M. Despite the increased apoptosis, a significant proportion of synchronized cells proceeded through S, G(2)-M, and into G(1) phase in the presence of flavopiridol, demonstrating that a high-grade cell cycle arrest is not required for apoptosis. Cells synchronized at the G(1)-S border treated with a short exposure to flavopiridol also showed more than a 10-fold decrease in clonogenicity compared with asynchronous cells treated identically.. Taken together, these data demonstrate that flavopiridol potently and selectively induces SCLC apoptosis preferentially during S phase, in a manner that involves early mitochondrial dysfunction without a requirement for a high-grade block to cell cycle progression. Furthermore, clonogenicity data suggests that prior S phase synchronization could be a highly effective way of enhancing the efficacy of bolus or short infusions of flavopiridol in the clinical setting.

Topics: Aphidicolin; Apoptosis; Blotting, Western; Carcinoma, Small Cell; Caspase 3; Caspases; Cell Division; Enzyme Inhibitors; Flavonoids; Flow Cytometry; Humans; In Situ Nick-End Labeling; Lung Neoplasms; Membrane Potentials; Mitochondria; Piperidines; Poly(ADP-ribose) Polymerases; S Phase; Tetrazolium Salts; Thiazoles; Tumor Cells, Cultured; Tumor Stem Cell Assay

Huperzine A (HupA) and donepezil, two novel selective acetylcholinesterase inhibitors available for Alzheimer's disease, were tested for their ability to alleviate injury from oxygen-glucose deprivation (OGD) in the rat pheochromocytoma line PC12 cells. OGD for 30 min triggered death in more than 50% of cells, along with major changes in morphology and biochemistry including elevated levels of lipid peroxide, superoxide disamutase activity and lactate. Cells pretreated for 2 h with HupA or donepezil showed improved survival and reduced biochemical and morphologic signs of toxicity (statistically significant over the range from 10 microM down to 1.0 and 0.1 microM, respectively). Our results indicated that HupA and donepezil protected PC12 cells against OGD-induced toxicity, most likely by alleviating disturbances of oxidative and energy metabolism.

Topics: Alkaloids; Alzheimer Disease; Animals; Cell Size; Cell Survival; Cholinesterase Inhibitors; Donepezil; Dose-Response Relationship, Drug; Glucose; Hypoxia-Ischemia, Brain; Indans; Lipid Peroxidation; Malondialdehyde; Neuroprotective Agents; Oxidative Stress; PC12 Cells; Piperidines; Rats; Sesquiterpenes; Superoxide Dismutase; Tetrazolium Salts; Thiazoles