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Genes To Cells : Devoted To Molecular &... Nov 2013Cell-in-cell structures represent live cell events in which one cell internalizes another. Because formation of cell-in-cell structures is a rare event in most cell...
Cell-in-cell structures represent live cell events in which one cell internalizes another. Because formation of cell-in-cell structures is a rare event in most cell types and the event is associated with cell death, there has been limited clarification of this phenomenon, and its physiological role and molecular mechanism are yet to be precisely elucidated. In this study, we established a mutagenized cell line that exhibited cell-in-cell structures at a more than 10-fold higher frequency as compared to the parent cells. Interestingly, both engulfment and invasion were increased in the mutagenized cell line as compared with that in the parent cell line in the suspension culture condition. This finding indicates that this mutagenized cell line showed an interchangeable status in terms of its ability to form cell-in-cell structures, and the system described here could be useful for elucidation of the mechanisms regulating the formation of cell-in-cell structures, including engulfment and invasion, in a given cellular environment. Further studies using this cell line are warranted to understand the mechanism of formation and biological significance of the cell-in-cell formation.
Topics: Aminacrine; Cell-in-Cell Formation; HCT116 Cells; Humans; Mutagenesis; Mutation Rate; Nitrogen Mustard Compounds; Phenotype
PubMed: 24165024
DOI: 10.1111/gtc.12092 -
Antimicrobial Agents and Chemotherapy Sep 1974A new antimicrobial nitrofuran designated SQ 18,506 showed some therapeutic activity when administered orally to mice infected with Escherichia coli, Salmonella...
A new antimicrobial nitrofuran designated SQ 18,506 showed some therapeutic activity when administered orally to mice infected with Escherichia coli, Salmonella schottmuelleri, Shigella flexneri, or Klebsiella pneumoniae. Animals infected parenterally with Streptococcus pyogenes, Proteus mirabilis, Mycobacterium tuberculosis, and Candida albicans, or topically with Trichophyton mentagrophytes, did not respond to therapy with the drug at the dosage levels used. The compound was as effective as metronidazole in the topical treatment of experimental trichomonal infections in mice and in guinea pigs and as effective as nystatin, candicidin, or a sulfanilamide-aminacrine hydrochloride cream in the treatment of a candidal vaginal infection in rats. The chemotherapeutic efficacy of SQ 18,506 in experimental vaginitis caused by Escherichia coli in the rat surpassed that shown by four commercial products available for the treatment of bacterial vaginitis.
Topics: 5-Amino-3-((5-nitro-2-furyl)vinyl)-1,2,4-oxadiazole; Animals; Anti-Infective Agents; Dermatomycoses; Female; Guinea Pigs; Infections; Male; Mice; Rats; Trichomonas Vaginitis; Vaginosis, Bacterial
PubMed: 15830472
DOI: 10.1128/AAC.6.3.268 -
Japanese Journal of Pharmacology Jun 1990The effects of the tacrine (THA) derivative SM-10888 (9-amino-8-fluoro-1,2,3,4-tetrahydro-2,4-methanoacridine citrate) on habituation and passive avoidance responses...
The effects of the tacrine (THA) derivative SM-10888 (9-amino-8-fluoro-1,2,3,4-tetrahydro-2,4-methanoacridine citrate) on habituation and passive avoidance responses were studied in mice. We examined its effects on habituation of exploratory activity, measured by photo-cell beam interruptions in a small, simple cage and cycloheximide (CXM)- or electroconvulsive shock (ECS)-induced stepdown type passive avoidance response (PAR) failures in comparison with those of THA, amiridin, HP-029 and physostigmine. SM-10888 (6 mg/kg, p.o.) administered post-acquisition session enhanced the retention of habituation. CXM- and ECS-induced PAR failures were improved by SM-10888 (6 mg/kg, p.o.) administered at pre-training or post-training, respectively. THA enhanced the retention of habituation and improved CXM-induced PAR failure at 30 mg/kg, p.o., but did not affect ECS-induced PAR failure at 1-15 mg/kg, p.o. Amiridin and HP-029 were also effective on habituation and CXM-induced PAR failure at 40-50 mg/kg, p.o., but did not affect ECS-induced PAR failure at the tested doses. Physostigmine showed a moderate improvement only in CXM-induced PAR failure. The results indicate that SM-10888 enhanced habituation and improved PAR failures at much lower doses than THA. This seems to depend on its high selectivity to the central nervous system.
Topics: Aminacrine; Aminoacridines; Aminoquinolines; Animals; Avoidance Learning; Cholinesterase Inhibitors; Cycloheximide; Electroshock; Exploratory Behavior; Habituation, Psychophysiologic; Male; Mice; Physostigmine; Tacrine
PubMed: 2385006
DOI: 10.1254/jjp.53.211 -
The Biochemical Journal Jan 19811. Mitochondria from Jerusalem artichoke (Helianthus tuberosus) tubers and Arum maculatum spadices caused a quenching of the fluorescence of 9-aminoacridine when mixed... (Comparative Study)
Comparative Study
1. Mitochondria from Jerusalem artichoke (Helianthus tuberosus) tubers and Arum maculatum spadices caused a quenching of the fluorescence of 9-aminoacridine when mixed in a low-cation medium (approximately 1 mM-K+) and addition of chelators further decreased the fluorescence. Salts released the quenching of the 9-aminoacridine fluorescence and the efficiency of the release appeared to be mainly dependent on the valency of the cation (C3+ greater than C2+ greater than C+). 2. The results are consistent with the theory of charge screening and demonstrate that 9-aminoacridine is a convenient probe of the behaviour of cations on the membranes of mitochondria and in the diffuse layer associated with these membranes. 3. The concentration of salt required to achieve half-maximal release of quenching of 9-aminoacridine fluorescence was proportional to the concentration of mitochondria in the solution and theoretical considerations show this effect to be inherent in the Gouy-Chapman theory. 4. 9-Aminoacridine was removed from the bulk of the solution by the mitochondria to a far greater extent than was Na+ or K+, which is suggested to be due to the formation of bi- and poly-valent cations by aggregation of 9-aminoacridine molecules in the diffuse layer. This would have implications for the use of 9-aminoacridine to determine delta pH across membranes. 5. Jerusalem-artichoke mitochondria removed from 9-aminoacridine and Ca2+ from the bulk of the solution and required more ions to screen the membranes than did an equal concentration (mg of protein/ml) of Arum mitochondria, indicating that Jerusalem-artichoke mitochondria contain more negative charges per mg of protein.
Topics: Aminacrine; Aminoacridines; Cations; Chelating Agents; Fluorescent Dyes; Intracellular Membranes; Membrane Potentials; Mitochondria; Plant Proteins; Plants
PubMed: 7305932
DOI: 10.1042/bj1930037 -
Biochimica Et Biophysica Acta Apr 2003This work reports the production of a liposomal formulation, having a lipidic membrane with known chemical composition and a low proton permeability, as confirmed by...
This work reports the production of a liposomal formulation, having a lipidic membrane with known chemical composition and a low proton permeability, as confirmed by physicochemical characterization of the maintenance of a transmembranic pH gradient. These liposomes consist of DSPC, DSPE-PEG, DSPG and cholesterol, with low internal pH. To verify the low proton permeability of these liposomal bilayers, a study of proton migration according to the fluorescence quenching of 9-aminoacridine (9AA), as well as CPT-11 encapsulation, were used to monitor the acidification of the intravesicular space. Both experiments showed that this liposomal formulation is able to maintain a transmembranic proton gradient.
Topics: Aminacrine; Camptothecin; Fluorescent Dyes; Hydrogen-Ion Concentration; Irinotecan; Liposomes; Membrane Lipids; Permeability; Protons; Spectrometry, Fluorescence
PubMed: 12659939
DOI: 10.1016/s0005-2736(03)00035-x -
Neuron Jan 2002Many N-methyl-D-aspartate receptor (NMDAR) channel blockers that have therapeutic potential can be trapped in the closed state. Using a combination of the substituted...
Many N-methyl-D-aspartate receptor (NMDAR) channel blockers that have therapeutic potential can be trapped in the closed state. Using a combination of the substituted cysteine accessibility method and open channel blockers, we found that the M3 segment forms the core of the extracellular vestibule, including a deep site for trapping blockers. The M3 segment, as well as more superficial parts of the extracellular vestibule, undergo extensive remodeling during channel closure, but do not define the activation gate, which is located deeper in the pore. Rather, the pore walls lining the extracellular vestibule constrict during channel closure. This movement is essential for coupling ligand binding to activation gate opening and accounts for the different mechanisms of open channel block, including trapping.
Topics: Aminacrine; Animals; Cell Membrane; Central Nervous System; Cysteine; Drug Interactions; Excitatory Amino Acid Antagonists; Extracellular Space; Female; Glutamic Acid; Ion Channel Gating; Membrane Potentials; Mutagens; Mutation; Oocytes; Protein Structure, Tertiary; Receptors, N-Methyl-D-Aspartate; Synaptic Transmission; Xenopus laevis
PubMed: 11779481
DOI: 10.1016/s0896-6273(01)00560-8 -
In Vivo (Athens, Greece) 2006A proton pump-deleted mutant E. coli, AG100 A, had greater sensitivity to ampicillin, tetracycline and erythromycin than the wild-type parent E. coli AG100 containing... (Comparative Study)
Comparative Study
A proton pump-deleted mutant E. coli, AG100 A, had greater sensitivity to ampicillin, tetracycline and erythromycin than the wild-type parent E. coli AG100 containing the proton pump. This antibiotic sensitivity was further increased by resistance modifiers such as the Ca2+ channel blocker (+/-) verapamil (VP) and the calmodulin antagonist promethazine (PMZ). Whereas the newly-synthesized trifluoromethyl-ketone (TF) enhanced the activity of these antibiotics against the wild-type strain, it did not enhance the activity of ampicillin against the proton pump-deleted mutant. These results suggested that TF14 had an inhibitory effect on the proton pump. Elimination of plasmids from another strain of E. coli, K12, was promoted by PMZ and 9-amino-acridine (9-AA), but not by TF14 alone. However, combinations of TF14 with either PMZ or 9-AA enhanced the plasmid elimination capacity of the latter compounds. The combination of TF14, PMZ and VP proved that the Ca2+ channel blocker was not effective by itself These results collectively suggest that TF14 inhibited the proton pump of E. coli and that it was this pump which, when inhibited by TF14, allowed more PMZ to reach its plasmid elimination target.
Topics: Aminacrine; Ampicillin; Anti-Bacterial Agents; Drug Resistance, Multiple; Drug Synergism; Erythromycin; Escherichia coli; Microbial Sensitivity Tests; Plasmids; Promethazine; Proton Pump Inhibitors; Tetracycline; Verapamil
PubMed: 16724672
DOI: No ID Found -
Proceedings of the National Academy of... Nov 2005Renal cell carcinomas (RCC) commonly retain wild-type but functionally inactive p53, which is repressed by an unknown dominant mechanism. To help reveal this mechanism,... (Comparative Study)
Comparative Study
Renal cell carcinomas (RCC) commonly retain wild-type but functionally inactive p53, which is repressed by an unknown dominant mechanism. To help reveal this mechanism, we screened a diverse chemical library for small molecules capable of restoring p53-dependent transactivation in RCC cells carrying a p53-responsive reporter. Among the compounds isolated were derivatives of 9-aminoacridine (9AA), including the antimalaria drug quinacrine, which strongly induced p53 function in RCC and other types of cancer cells. Induction of p53 by these compounds does not involve genotoxic stress and is mediated by suppression of NF-kappaB activity. In contrast to agents that target IkappaB kinase 2, 9AA and quinacrine can effectively suppress both basal and inducible activities of NF-kappaB, representing inhibitors of a previously undescribed type that convert NF-kappaB from a transactivator into a transrepressor, leading to accumulation of inactive nuclear complexes with unphosphorylated Ser-536 in the p65/RelA subunit. p53 function in RCC can be restored by ectopic expression of a superrepressor of IkappaB as effectively as by 9AA-derived compounds. These findings suggest that the complete or partial repression of p53 observed in many tumors can be the result of constitutive activation of NF-kappaB. The results demonstrate, in principle, the possibility to kill cancer cells selectively through simultaneous inhibition of NF-kappaB and activation of p53 by a single small molecule and suggest anticancer applications for the well known antimalaria drug quinacrine.
Topics: Aminacrine; Carcinoma, Renal Cell; Cell Line, Tumor; Colorimetry; Gene Expression Regulation, Neoplastic; Humans; NF-kappa B; Quinacrine; Structure-Activity Relationship; Tumor Suppressor Protein p53; beta-Galactosidase
PubMed: 16287968
DOI: 10.1073/pnas.0508888102 -
Biochimica Et Biophysica Acta Jan 2002We have previously shown that anacardic acid has an uncoupling effect on oxidative phosphorylation in rat liver mitochondria using succinate as a substrate (Life Sci. 66...
We have previously shown that anacardic acid has an uncoupling effect on oxidative phosphorylation in rat liver mitochondria using succinate as a substrate (Life Sci. 66 (2000) 229-234). In the present study, for clarification of the physicochemical characteristics of anacardic acid, we used a cyanine dye (DiS-C3(5)) and 9-aminoacridine (9-AA) to determine changes of membrane potential (DeltaPsi) and pH difference (DeltapH), respectively, in a liposome suspension in response to the addition of anacardic acid to the suspension. The anacardic acid quenched DiS-C3(5) fluorescence at concentrations higher than 300 nM, with the degree of quenching being dependent on the log concentration of the acid. Furthermore, the K(+) diffusion potential generated by the addition of valinomycin to the suspension decreased for each increase in anacardic acid concentration used over 300 nM, but the sum of the anacardic acid- and valinomycin-mediated quenching was additively increasing. This indicates that the anacardic acid-mediated quenching was not due simply to increments in the K(+) permeability of the membrane. Addition of anacardic acid in the micromolar range to the liposomes with DeltaPsi formed by valinomycin-K(+) did not significantly alter 9-AA fluorescence, but unexpectedly dissipated DeltaPsi. The DeltaPsi preformed by valinomycin-K(+) decreased gradually following the addition of increasing concentrations of anacardic acid. The DeltaPsi dissipation rate was dependent on the pre-existing magnitude of DeltaPsi, and was correlated with the logarithmic concentration of anacardic acid. Furthermore, the initial rate of DeltapH dissipation increased with logarithmic increases in anacardic acid concentration. These results provide the evidence for a unique function of anacardic acid, dissimilar to carbonylcyanide p-trifluoromethoxyphenylhydrazone or valinomycin, in that anacardic acid behaves as both an electrogenic (negative) charge carrier driven by DeltaPsi, and a 'proton carrier' that dissipates the transmembrane proton gradient formed.
Topics: Aminacrine; Anacardic Acids; Benzothiazoles; Carbocyanines; Carbonyl Cyanide p-Trifluoromethoxyphenylhydrazone; Dose-Response Relationship, Drug; Fluorescent Dyes; Gramicidin; Hydrogen-Ion Concentration; Liposomes; Membrane Potentials; Models, Chemical; Molecular Structure; Salicylates; Spectrometry, Fluorescence; Valinomycin
PubMed: 11750264
DOI: 10.1016/s0005-2736(01)00422-9 -
Japanese Journal of Pharmacology Jun 1990The effects of the compound SM-10888 (9-amino-8-fluoro-1,2,3,4-tetrahydro-2,4-methanoacridine citrate) in a number of pharmacological and biochemical tests were studied... (Comparative Study)
Comparative Study
The effects of the compound SM-10888 (9-amino-8-fluoro-1,2,3,4-tetrahydro-2,4-methanoacridine citrate) in a number of pharmacological and biochemical tests were studied and compared to those of tacrine (THA), amiridin, HP-029 and physostigmine. SM-10888 inhibited cholinesterase activity (IC50: 2.3 x 10(-7) M) in rat cortical P2 fraction with almost the same potency as THA, while SM-10888 was 2-4 times more potent than amiridin and HP-029, but about 10 times less potent than physostigmine. When given to mice p.o., SM-10888 induced central (hypothermia) and peripheral (salivation) cholinergic effects. When the ratio of the ED50 value for hypothermia to that for salivation was regarded as the index of the selectivity to the central nervous system (CNS), SM-10888 was shown to be about 3 times more selective to the CNS than the other four drugs in mice. The minimum effective dose of SM-10888 for its increasing effect on acetylcholine (ACh) content in the mouse cerebral cortex was about 10 times higher than that of physostigmine, but 5-10 times lower than those of THA, amiridin and HP-029. These results suggest that SM-10888 is an adequate drug for increasing the brain ACh content with less peripheral cholinergic side effects than THA, amiridin, HP-029 and physostigmine.
Topics: Aminacrine; Aminoacridines; Aminoquinolines; Animals; Body Temperature; Cerebral Cortex; Cholinesterase Inhibitors; Dose-Response Relationship, Drug; Male; Mice; Nucleic Acids; Physostigmine; Rats; Salivation; Tacrine
PubMed: 2385001
DOI: 10.1254/jjp.53.145