Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 27
Filter
Add more filters










Publication year range
1.
Cureus ; 15(11): e49151, 2023 Nov.
Article in English | MEDLINE | ID: mdl-38130506

ABSTRACT

BACKGROUND: The presumed etiology of vestibular neuritis (VN), a sudden onset of spontaneous vertigo without auditory or cranial nerve symptoms, includes viral infections and vascular disorders. However, no clinical test for estimating vascular disorders in VN has been reported. Moreover, estimating the etiology of VN is important to predict the prognosis and select appropriate treatment. This study aimed to evaluate the cardio-ankle vascular index (CAVI), which reflects arterial stiffness and elasticity, as an additional indicator for estimating the prognosis and etiology of VN. MATERIALS AND METHODS: Among 207 consecutive patients with suspected VN, 88 patients diagnosed with definite VN were enrolled. Age, initial and final percent canal paresis (CP) in the caloric test, CAVI, presence or absence of vestibular-evoked myogenic potential asymmetry, and medical history were evaluated using univariate and multivariate analyses. RESULTS: Patients with VN with high CAVI had a better prognosis than those with low CAVI. High CAVI was a factor for improvement in percent CP, in addition to younger age and less severe initial percent CP in the Cox proportional hazard model. CONCLUSION: CAVI can be an additional indicator for estimating the prognosis and etiology of VN. This indicator can potentially be applied to other diseases, including vascular disorders with other etiologies.

2.
J Biosci Bioeng ; 133(2): 155-160, 2022 Feb.
Article in English | MEDLINE | ID: mdl-34863625

ABSTRACT

Lactic acid bacteria (LAB) and yeast coexist by providing nutrients as substrates for each other. LAB and yeast cells aggregate via specific interactions between mannose on the yeast surface and the mannose-binding protein (MBP) on the LAB surface. In addition to specific interactions via cell surface proteins, there are also nonspecific interactions related to microbial coaggregation; the extent of their contributions is not clear. Here, microbial coaggregation of yeast and LAB cells was investigated from the view point of particle technology. DLVO theory and thermodynamic approaches predicted that thermodynamically stable coaggregates are not formed because no hydrophobic interaction acts between yeast and LAB. In contrast, optical microscopy revealed that yeast with mannose and LAB with MBP were formed submillimeter-sized coaggregates, whereas deficient strains of yeast and/or LAB were dispersed. Single-cell force spectroscopy revealed that the median adhesion forces were less than 100 pN for all combinations of yeast and LAB. However, some of the adhesion forces between yeast with mannose and LAB with MBP were greater than 400 pN. Furthermore, in the presence of a microbial coaggregation inhibitor, coaggregation of yeast with mannose and LAB with MBP was suppressed, and the adhesion forces were less than 300 pN. These results indicate that the specific interaction rather than the nonspecific interactions acted between mannose on the yeast and the MBP on the LAB formed submillimeter-sized small aggregates. Understanding the contribution of predominant cell-cell interactions may help control microbial behavior in biotechnology.


Subject(s)
Lactic Acid , Saccharomyces cerevisiae , Cell Adhesion , Hydrophobic and Hydrophilic Interactions , Mannose , Microscopy, Atomic Force , Saccharomyces cerevisiae/genetics
3.
PLoS One ; 15(10): e0240718, 2020.
Article in English | MEDLINE | ID: mdl-33064779

ABSTRACT

Emerging evidence indicates that alternative splicing plays a critical role in cancer progression through abnormal expression or mutation of splicing factors. Small-molecule splicing modulators have recently attracted considerable attention as a novel class of cancer therapeutics. CDC-like kinases (CLKs) are central to exon recognition in mRNA splicing and CLK inhibitors exhibit anti-tumour activities. Most importantly, molecular mechanism-based combination strategies for cancer therapy must be considered. However, it remains unclear whether CLK inhibitors modulate expression and splicing of apoptosis-related genes, and whether CLK inhibitors enhance cytotoxicity in combination with apoptosis inducers. Here we report an appropriate mechanism-based drug combination approach. Unexpectedly, we found that the CLK inhibitor T3 rapidly induced apoptosis in A2780 cells and G2/M cell cycle arrest in HCT116 cells. Regardless of the different phenotypes of the two cancer cell types, T3 decreased the levels of anti-apoptotic proteins (cIAP1, cIAP2, XIAP, cFLIP and Mcl-1) for a short period of exposure and altered the splicing of the anti-apoptotic MCL1L and CFLAR isoform in A2780 and HCT116 cells. In contrast, other members of the Bcl-2 family (i.e., Bcl-xL and Bcl-2) were resistant to T3-induced expression and splicing modulation. T3 and a Bcl-xL/Bcl-2 inhibitor synergistically induced apoptosis. Taken together, the use of a CLK inhibitor is a novel therapeutic approach to sensitise cancer cells to Bcl-xL/Bcl-2 inhibitors.


Subject(s)
Antineoplastic Agents/pharmacology , Apoptosis/drug effects , Protein Kinase Inhibitors/pharmacology , Protein Serine-Threonine Kinases/antagonists & inhibitors , Protein-Tyrosine Kinases/antagonists & inhibitors , Proto-Oncogene Proteins c-bcl-2/antagonists & inhibitors , Alternative Splicing/drug effects , Antineoplastic Agents/chemistry , Apoptosis/genetics , CASP8 and FADD-Like Apoptosis Regulating Protein/metabolism , Cell Cycle Checkpoints/drug effects , Cell Line, Tumor , Cell Proliferation/drug effects , Drug Synergism , G2 Phase/drug effects , Humans , Mechanistic Target of Rapamycin Complex 2/metabolism , Myeloid Cell Leukemia Sequence 1 Protein/genetics , Myeloid Cell Leukemia Sequence 1 Protein/metabolism , Proteasome Endopeptidase Complex/metabolism , Protein Kinase Inhibitors/chemistry , Protein Kinase Inhibitors/pharmacokinetics , RNA Precursors/genetics , RNA Precursors/metabolism
4.
J Med Chem ; 63(3): 1084-1104, 2020 02 13.
Article in English | MEDLINE | ID: mdl-31895562

ABSTRACT

In our pursuit of developing a novel, potent, and selective cell division cycle 7 (Cdc7) inhibitor, we optimized the previously reported thieno[3,2-d]pyrimidinone analogue I showing time-dependent Cdc7 kinase inhibition and slow dissociation kinetics. These medicinal chemistry efforts led to the identification of compound 3d, which exhibited potent cellular activity, excellent kinase selectivity, and antitumor efficacy in a COLO205 xenograft mouse model. However, the issue of formaldehyde adduct formation emerged during a detailed study of 3d, which was deemed an obstacle to further development. A structure-based approach to circumvent the adduct formation culminated in the discovery of compound 11b (TAK-931) possessing a quinuclidine moiety as a preclinical candidate. In this paper, the design, synthesis, and biological evaluation of this series of compounds will be presented.


Subject(s)
Antineoplastic Agents/therapeutic use , Cell Cycle Proteins/antagonists & inhibitors , Protein Kinase Inhibitors/therapeutic use , Protein Serine-Threonine Kinases/antagonists & inhibitors , Pyrazolones/therapeutic use , Pyrimidines/therapeutic use , Pyrimidinones/therapeutic use , Quinuclidines/therapeutic use , Thiophenes/therapeutic use , Animals , Antineoplastic Agents/chemical synthesis , Antineoplastic Agents/metabolism , Binding Sites , Cell Cycle Proteins/chemistry , Cell Cycle Proteins/metabolism , Cell Line, Tumor , Drug Design , Drug Discovery , Formaldehyde/chemistry , Humans , Mice , Molecular Docking Simulation , Molecular Structure , Protein Binding , Protein Kinase Inhibitors/chemical synthesis , Protein Kinase Inhibitors/metabolism , Protein Serine-Threonine Kinases/chemistry , Protein Serine-Threonine Kinases/metabolism , Pyrazolones/pharmacology , Pyrimidines/pharmacology , Pyrimidinones/chemical synthesis , Pyrimidinones/metabolism , Quinuclidines/chemical synthesis , Quinuclidines/metabolism , Structure-Activity Relationship , Thiophenes/chemical synthesis , Thiophenes/metabolism , Xenograft Model Antitumor Assays
5.
EMBO Mol Med ; 10(6)2018 06.
Article in English | MEDLINE | ID: mdl-29769258

ABSTRACT

The modulation of pre-mRNA splicing is proposed as an attractive anti-neoplastic strategy, especially for the cancers that exhibit aberrant pre-mRNA splicing. Here, we discovered that T-025 functions as an orally available and potent inhibitor of Cdc2-like kinases (CLKs), evolutionally conserved kinases that facilitate exon recognition in the splicing machinery. Treatment with T-025 reduced CLK-dependent phosphorylation, resulting in the induction of skipped exons, cell death, and growth suppression in vitro and in vivo Further, through growth inhibitory characterization, we identified high CLK2 expression or MYC amplification as a sensitive-associated biomarker of T-025. Mechanistically, the level of CLK2 expression correlated with the magnitude of global skipped exons in response to T-025 treatment. MYC activation, which altered pre-mRNA splicing without the transcriptional regulation of CLKs, rendered cancer cells vulnerable to CLK inhibitors with synergistic cell death. Finally, we demonstrated in vivo anti-tumor efficacy of T-025 in an allograft model of spontaneous, MYC-driven breast cancer, at well-tolerated dosage. Collectively, our results suggest that the novel CLK inhibitor could have therapeutic benefits, especially for MYC-driven cancer patients.


Subject(s)
Diamines/pharmacology , Protein Kinase Inhibitors/pharmacology , Protein Serine-Threonine Kinases/antagonists & inhibitors , Protein-Tyrosine Kinases/antagonists & inhibitors , Pyrimidines/pharmacology , Quinolines/pharmacology , RNA Splicing/drug effects , Animals , Cell Line, Tumor , Diamines/chemistry , Genes, myc , Humans , Mice , Mice, Transgenic , Phosphorylation , Protein Kinase Inhibitors/chemistry , Protein Serine-Threonine Kinases/metabolism , Protein-Tyrosine Kinases/metabolism , Proto-Oncogene Proteins c-myc/genetics , Proto-Oncogene Proteins c-myc/metabolism , Proto-Oncogene Proteins c-myc/physiology , Pyrimidines/chemistry , Quinolines/chemistry , RNA Splicing/genetics
6.
J Colloid Interface Sci ; 513: 1-9, 2018 Mar 01.
Article in English | MEDLINE | ID: mdl-29128617

ABSTRACT

Poly lactic-co-glycolic acid (PLGA) has attracted considerable attention as a polymer for drug delivery carriers. However, the hydrophobic property of PLGA often leads to the use of harmful organic solvents and poor encapsulation efficiency of hydrophilic materials. To our knowledge, a preparation method of aqueous core PLGA microcapsules without using harmful organic solvents has not been proposed. In this study, we attempted to establish an encapsulation technique of hydrophilic materials in aqueous core biodegradable and biocompatible PLGA microcapsules using vegetable oil as a continuous phase. As a result, the temperature of the oil/water mixture was required to be above the glass transition temperature. In this condition, two different types of morphology were prepared. When the water volume was below the solubility limit, PLGA microcapsules with a smooth shell were formed. In contrast, when the water volume was above the solubility limit, colloidosome-like microcapsules with PLGA nanoparticles assembled at the interface were formed. The obtained microcapsules were then heated at the glass transition temperature. The result is that aqueous core PLGA microcapsules with a smooth shell were prepared using plant oil as a continuous phase. Rhodamine B used as a hydrophilic model encapsulant, was successfully encapsulated in the PLGA microcapsules.


Subject(s)
Capsules/chemistry , Drug Carriers/chemistry , Emulsions , Lactic Acid/chemical synthesis , Microspheres , Polyglycolic Acid/chemical synthesis , Polylactic Acid-Polyglycolic Acid Copolymer , Rhodamines/metabolism , Solvents
7.
Anticancer Res ; 37(11): 6125-6132, 2017 11.
Article in English | MEDLINE | ID: mdl-29061793

ABSTRACT

BACKGROUND: Several reports have shown that the overexpression of the MET proto-oncogene, receptor tyrosine kinase (MET), was more frequently observed in clear cell carcinoma (CCC) than in non-CCC. We evaluated the antitumor activity of cabozantinib, that targets MET. MATERIALS AND METHODS: A gene expression analysis of tumors from human ovarian cancers was carried out by transcriptome sequencing. An in vitro 3-(4, 5-dimethylthiazolyl-2)-2, 5-diphenyltetrazolium bromide assay (MTT assay) and in vivo experiments were performed to determine the activity of cabozantinib. RESULTS: The MET levels were higher in tumors with CCC than high-grade serous carcinoma (2.2-fold). Cabozantinib inhibited cell viability and phosphorylation of AKT and MAPK under the treatment of hepatocyte growth factor in RMG-I CCC cells. The tumors removed from mice given cabozantinib of 10 mg/kg weighed 70% less than control on day 15, and the immunohistochemical reactivity of phosphorylated MET was reduced compared with control mice. CONCLUSION: Cabozantinib contributes to tumor reduction, and phosphorylated MET represents an attractive target of CCC.


Subject(s)
Adenocarcinoma, Clear Cell/pathology , Anilides/pharmacology , Apoptosis/drug effects , Ovarian Neoplasms/pathology , Pyridines/pharmacology , Adenocarcinoma, Clear Cell/drug therapy , Adenocarcinoma, Clear Cell/metabolism , Animals , Cell Proliferation/drug effects , Female , Humans , In Vitro Techniques , Mice , Mice, Inbred BALB C , Mice, Nude , Ovarian Neoplasms/drug therapy , Ovarian Neoplasms/metabolism , Phosphorylation/drug effects , Protein Kinase Inhibitors/pharmacology , Proto-Oncogene Mas , Proto-Oncogene Proteins c-met/antagonists & inhibitors , Signal Transduction/drug effects , Tumor Cells, Cultured , Vascular Endothelial Growth Factor Receptor-2/antagonists & inhibitors , Xenograft Model Antitumor Assays
8.
Cancer Res ; 77(17): 4652-4662, 2017 09 01.
Article in English | MEDLINE | ID: mdl-28667074

ABSTRACT

T-3775440 is an irreversible inhibitor of the chromatin demethylase LSD1, which exerts antiproliferative effects by disrupting the interaction between LSD1 and GFI1B, a SNAG domain transcription factor, inducing leukemia cell transdifferentiation. Here, we describe the anticancer effects and mechanism of action of T-3775440 in small-cell lung cancer (SCLC). T-3775440 inhibited proliferation of SCLC cells in vitro and retarded SCLC tumor growth in vivo T-3775440 disrupted the interaction between LSD1 and the transcriptional repressor INSM1, thereby inhibiting expression of neuroendocrine-associated genes, such as ASCL1 INSM1 silencing phenocopied the effects of T-3775440 on gene expression and cell proliferation, consistent with the likelihood T-3775440 mediated its effects in SCLC by inhibiting INSM1. T-3775440 also inhibited proliferation of an SCLC cell line that overexpressed GFI1B, rather than INSM1, by disrupting the interaction between LSD1 and GFI1B. Taken together, our results argue that LSD1 plays an important role in neuroendocrine-associated transcription and cell proliferation of SCLC via interactions with the SNAG domain proteins INSM1 and GFI1B. Targeting these critical interactions with LSD1 inhibitors offers a novel rational strategy to therapeutically manage SCLC. Cancer Res; 77(17); 4652-62. ©2017 AACR.


Subject(s)
Anilides/pharmacology , Antineoplastic Agents/pharmacology , Cell Proliferation/drug effects , Cyclopropanes/pharmacology , Histone Demethylases/antagonists & inhibitors , Protein Interaction Domains and Motifs/drug effects , Proto-Oncogene Proteins/antagonists & inhibitors , Repressor Proteins/antagonists & inhibitors , Small Cell Lung Carcinoma/drug therapy , Animals , Female , Histone Demethylases/metabolism , Humans , Lung Neoplasms/drug therapy , Lung Neoplasms/metabolism , Lung Neoplasms/pathology , Mice, Inbred BALB C , Mice, Nude , Proto-Oncogene Proteins/metabolism , Repressor Proteins/metabolism , Small Cell Lung Carcinoma/metabolism , Small Cell Lung Carcinoma/pathology , Snail Family Transcription Factors , Tumor Cells, Cultured , Xenograft Model Antitumor Assays
9.
Nat Commun ; 8(1): 7, 2017 02 23.
Article in English | MEDLINE | ID: mdl-28232751

ABSTRACT

CDC-like kinase phosphorylation of serine/arginine-rich proteins is central to RNA splicing reactions. Yet, the genomic network of CDC-like kinase-dependent RNA processing events remains poorly defined. Here, we explore the connectivity of genomic CDC-like kinase splicing functions by applying graduated, short-exposure, pharmacological CDC-like kinase inhibition using a novel small molecule (T3) with very high potency, selectivity, and cell-based stability. Using RNA-Seq, we define CDC-like kinase-responsive alternative splicing events, the large majority of which monotonically increase or decrease with increasing CDC-like kinase inhibition. We show that distinct RNA-binding motifs are associated with T3 response in skipped exons. Unexpectedly, we observe dose-dependent conjoined gene transcription, which is associated with motif enrichment in the last and second exons of upstream and downstream partners, respectively. siRNA knockdown of CLK2-associated genes significantly increases conjoined gene formation. Collectively, our results reveal an unexpected role for CDC-like kinase in conjoined gene formation, via regulation of 3'-end processing and associated splicing factors.The phosphorylation of serine/arginine-rich proteins by CDC-like kinase is a central regulatory mechanism for RNA splicing reactions. Here, the authors synthesize a novel small molecule CLK inhibitor and map CLK-responsive alternative splicing events and discover an effect on conjoined gene transcription.


Subject(s)
Alternative Splicing/drug effects , Imidazoles/pharmacology , Protein Kinase Inhibitors/pharmacology , Protein Serine-Threonine Kinases/genetics , Protein-Tyrosine Kinases/genetics , Pyrimidines/pharmacology , RNA, Messenger/genetics , RNA-Binding Proteins/genetics , Exons , Gene Expression Profiling , Genome, Human , HCT116 Cells , Humans , Imidazoles/chemical synthesis , Phosphorylation/drug effects , Protein Kinase Inhibitors/chemical synthesis , Protein Serine-Threonine Kinases/antagonists & inhibitors , Protein Serine-Threonine Kinases/metabolism , Protein-Tyrosine Kinases/antagonists & inhibitors , Protein-Tyrosine Kinases/metabolism , Pyrimidines/chemical synthesis , RNA, Messenger/antagonists & inhibitors , RNA, Messenger/metabolism , RNA, Small Interfering/genetics , RNA, Small Interfering/metabolism , RNA-Binding Proteins/antagonists & inhibitors , RNA-Binding Proteins/metabolism , Structure-Activity Relationship , Transcription, Genetic
10.
Mol Cancer Ther ; 16(2): 273-284, 2017 02.
Article in English | MEDLINE | ID: mdl-27903753

ABSTRACT

Dysregulation of lysine (K)-specific demethylase 1A (LSD1), also known as KDM1A, has been implicated in the development of various cancers, including leukemia. Here, we describe the antileukemic activity and mechanism of action of T-3775440, a novel irreversible LSD1 inhibitor. Cell growth analysis of leukemia cell lines revealed that acute erythroid leukemia (AEL) and acute megakaryoblastic leukemia cells (AMKL) were highly sensitive to this compound. T-3775440 treatment enforced transdifferentiation of erythroid/megakaryocytic lineages into granulomonocytic-like lineage cells. Mechanistically, T-3775440 disrupted the interaction between LSD1 and growth factor-independent 1B (GFI1B), a transcription factor critical for the differentiation processes of erythroid and megakaryocytic lineage cells. Knockdown of LSD1 and GFI1B recapitulated T-3775440-induced transdifferentiation and cell growth suppression, highlighting the significance of LSD1-GFI1B axis inhibition with regard to the anti-AML effects of T-3775440. Moreover, T-3775440 exhibited significant antitumor efficacy in AEL and AMKL xenograft models. Our findings provide a rationale for evaluating LSD1 inhibitors as potential treatments and indicate a novel mechanism of action against AML, particularly AEL and AMKL. Mol Cancer Ther; 16(2); 273-84. ©2016 AACR.


Subject(s)
Antineoplastic Agents/pharmacology , Cell Transdifferentiation/drug effects , Histone Demethylases/antagonists & inhibitors , Leukemia, Myeloid, Acute/metabolism , Leukemia, Myeloid, Acute/pathology , Multiprotein Complexes/metabolism , Proto-Oncogene Proteins/metabolism , Repressor Proteins/metabolism , Animals , Antineoplastic Agents/chemistry , Cell Line, Tumor , Cell Proliferation/drug effects , Cluster Analysis , Computational Biology/methods , Disease Models, Animal , Drug Resistance, Neoplasm , Female , Gene Expression Profiling , Gene Knockdown Techniques , Hematopoiesis/genetics , Histone Demethylases/genetics , Histone Demethylases/metabolism , Humans , Leukemia, Myeloid, Acute/drug therapy , Leukemia, Myeloid, Acute/genetics , Mice , Molecular Targeted Therapy , Protein Binding , Proto-Oncogene Proteins/genetics , Repressor Proteins/genetics , Xenograft Model Antitumor Assays
11.
Chemosphere ; 149: 84-90, 2016 Apr.
Article in English | MEDLINE | ID: mdl-26855210

ABSTRACT

The effects of surface physicochemical properties of functionalized polystyrene latex (PSL) nanoparticles (NPs) and model filamentous fungi Aspergillus oryzae and Aspergillus nidulans cultivated in different environment (aqueous and atmospheric environment) on the colloidal behavior and cytotoxicity were investigated in different isotonic solutions (154 mM NaCl and 292 mM sucrose). When the liquid cultivated fungal cells were exposed to positively charged PSL NPs in 154 mM NaCl solution, the NPs were taken into A. oryzae, but not A. nidulans. Atomic force microscopy revealed that the uptake of NPs was more readily through the cell wall of A. oryzae because of its relatively softer cell wall compared with A. nidulans. In contrast, the positively charged PSL NPs entirely covered the liquid cultivated fungal cell surfaces and induced cell death in 292 mM sucrose solution because of the stronger electrostatic attractive force between the cells and NPs compared with in 154 mM NaCl. When the agar cultivated fungal cells were exposed to the positively charged PSL NPs, both fungal cells did not take the NPs inside the cells. Contact angle measurement revealed that the hydrophobin on the agar cultivated cell surfaces inhibited the uptake of NPs because of its relatively more hydrophobic cell surface compared with the liquid cultivated cells.


Subject(s)
Environmental Pollutants/toxicity , Fungi/drug effects , Nanoparticles/toxicity , Polystyrenes/toxicity , Environmental Pollutants/chemistry , Hydrophobic and Hydrophilic Interactions , Isotonic Solutions , Microscopy, Atomic Force , Nanoparticles/chemistry , Polystyrenes/chemistry , Surface Properties , Toxicity Tests
12.
Colloids Surf B Biointerfaces ; 131: 67-72, 2015 Jul 01.
Article in English | MEDLINE | ID: mdl-25956746

ABSTRACT

The effects of the presence or absence of microbial flagella and the microbial motility on the colloidal behaviors of microbial cells were quantitatively evaluated. The microbial cell attachment and detachment processes on a glass surface were observed directly using a parallel-plate flow chamber. Wild-type, flagellar paralyzed, and nonflagellated Escherichia coli strains were used as model microbial cells. In the cell attachment tests, the microbial adhesion rate in a 160mM NaCl solution was approximately 10 times higher than that in a 10mM solution, for all E. coli strains. The colloidal behavior of the microbial cells agreed well with the predictions of the DLVO theory. In addition, the microbial flagella and motility did not significantly affect the cell attachment, regardless of the existence of a potential barrier between the cell and the glass substratum. In the cell detachment tests, the cumulative number of microbial cells detached from the glass substratum with increasing flow rate was fit well with the Weibull distribution function. The list of strains arranged in order of increasing median drag force required to remove them was nonflagellated strain, flagellar paralyzed strain, and wild-type strain. These results indicated that the flagella and the flagellar motility inhibited the cell detachment from the glass substratum. Furthermore, a large external force would likely be required to inhibit the microbial adhesion in the early stage of the biofilm formation.


Subject(s)
Bacterial Adhesion/physiology , Escherichia coli/physiology , Flagella/physiology , Glass/chemistry , Adhesives/chemistry , Algorithms , Bacterial Adhesion/genetics , Bacteriological Techniques/instrumentation , Bacteriological Techniques/methods , Biofilms/drug effects , Biofilms/growth & development , Escherichia coli/drug effects , Escherichia coli/genetics , Flagella/genetics , Mechanical Phenomena , Models, Biological , Mutation , Sodium Chloride/pharmacology , Static Electricity , Surface Properties
13.
PLoS One ; 10(1): e0116929, 2015.
Article in English | MEDLINE | ID: mdl-25581376

ABSTRACT

Accumulating evidence has demonstrated the importance of alternative splicing in various physiological processes, including the development of different diseases. CDC-like kinases (CLKs) and serine-arginine protein kinases (SRPKs) are components of the splicing machinery that are crucial for exon selection. The discovery of small molecule inhibitors against these kinases is of significant value, not only to delineate the molecular mechanisms of splicing, but also to identify potential therapeutic opportunities. Here we describe a series of small molecules that inhibit CLKs and SRPKs and thereby modulate pre-mRNA splicing. Treatment with these small molecules (Cpd-1, Cpd-2, or Cpd-3) significantly reduced the levels of endogenous phosphorylated SR proteins and caused enlargement of nuclear speckles in MDA-MB-468 cells. Additionally, the compounds resulted in splicing alterations of RPS6KB1 (S6K), and subsequent depletion of S6K protein. Interestingly, the activity of compounds selective for CLKs was well correlated with the activity for modulating S6K splicing as well as growth inhibition of cancer cells. A comprehensive mRNA sequencing approach revealed that the inhibitors induced splicing alterations and protein depletion for multiple genes, including those involved in growth and survival pathways such as S6K, EGFR, EIF3D, and PARP. Fluorescence pulse-chase labeling analyses demonstrated that isoforms with premature termination codons generated after treatment with the CLK inhibitors were degraded much faster than canonical mRNAs. Taken together, these results suggest that CLK inhibitors exhibit growth suppression and apoptosis induction through splicing alterations in genes involved in growth and survival. These small molecule inhibitors may be valuable tools for elucidating the molecular machinery of splicing and for the potential development of a novel class of antitumor agents.


Subject(s)
Apoptosis/drug effects , Cell Proliferation/drug effects , Protein Kinase Inhibitors/pharmacology , Protein Serine-Threonine Kinases/antagonists & inhibitors , Protein-Tyrosine Kinases/antagonists & inhibitors , RNA Splicing/drug effects , RNA, Messenger/genetics , Small Molecule Libraries/pharmacology , Apoptosis/genetics , Arginine/antagonists & inhibitors , Arginine/metabolism , Cell Line, Tumor , Cell Proliferation/genetics , HCT116 Cells , Humans , Nuclear Proteins/antagonists & inhibitors , Nuclear Proteins/metabolism , Phosphorylation/drug effects , Phosphorylation/genetics , Protein Isoforms/antagonists & inhibitors , Protein Isoforms/metabolism , Protein Serine-Threonine Kinases/metabolism , Protein-Tyrosine Kinases/metabolism , RNA Precursors/genetics , RNA Precursors/metabolism , RNA Splicing/genetics , RNA-Binding Proteins/metabolism
14.
J Colloid Interface Sci ; 432: 77-85, 2014 Oct 15.
Article in English | MEDLINE | ID: mdl-25086382

ABSTRACT

HYPOTHESIS: It was predicted that the colloidal behaviors of archaea and bacteria with disparate surface structure were different. In this study, the effects of the physicochemical properties of microbial cell surfaces on colloidal behavior were analyzed with Derjaguin-Landau-Verwey-Overbeek (DLVO) theory, thermodynamics, and powder technology. EXPERIMENTS: Cell attachment and detachment from model substrates were directly observed using a parallel plate flow chamber. Gram-negative Escherichia coli and archaeal Methanosarcina barkeri were used as model microbial cells, and positively and negatively charged glass slides were used as model substrates. FINDINGS: Microbial adhesion on both substrates agreed well with predictions calculated from DLVO theory, using experimental parameters. The total number of cells detached from the substrates as a function of flow rate was fit with the Weibull distribution function. In addition, the drag force required for detachment, which was estimated from the hydrodynamic forces, had a wide distribution; however, the forces became smaller with increasing ionic strength because of reduced electrostatic interactions between the cells and the substrate. M. barkeri could not be detached from positively charged substrates because it would entail a negative change in the interfacial energy of interaction. Thus adhesion was thermodynamically favored in this case.

15.
Environ Sci Technol ; 47(7): 3417-23, 2013 Apr 02.
Article in English | MEDLINE | ID: mdl-23448545

ABSTRACT

Novel nanoparticles with unique physicochemical characteristics are being developed with increasing frequency, leading to higher probability of nanoparticle release and environmental accumulation. Therefore, it is important to assess the potential environmental and biological adverse effects of nanoparticles. In this study, we investigated the toxicity and behavior of surface-functionalized nanoparticles toward yeast (Saccharomyces cerevisiae). The colony count method and confocal microscopy were used to examine the cytotoxicity of manufactured polystyrene latex (PSL) nanoparticles with various functional groups (amine, carboxyl, sulfate, and nonmodified). S. cerevisiae were exposed to PSL nanoparticles (40 mg/L) dispersed in 5-154 mM NaCl solutions for 1 h. Negatively charged nanoparticles had little or no toxic effect. Interestingly, nanoparticles with positively charged amine groups (p-Amine) were not toxic in 154 mM NaCl, but highly toxic in 5 mM NaCl. Confocal microscopy indicated that in 154 mM NaCl, the p-Amine nanoparticles were internalized by endocytosis, whereas in 5 mM NaCl they covered the dead cell surfaces. This demonstrates that nanoparticle-induced cell death might to be related to their adhesion to cells rather than their internalization. Together, these findings identify important factors in determining nanoparticle toxicity that might affect their impact on the environment and human health.


Subject(s)
Nanoparticles/chemistry , Nanoparticles/toxicity , Polystyrenes/chemistry , Polystyrenes/toxicity , Saccharomyces cerevisiae/drug effects , Static Electricity , Electrophoresis , Humans , Microbial Viability/drug effects , Microscopy, Confocal , Osmolar Concentration , Saccharomyces cerevisiae/cytology , Surface Properties , Time-Lapse Imaging
16.
Mol Cancer Ther ; 12(4): 460-70, 2013 Apr.
Article in English | MEDLINE | ID: mdl-23358665

ABSTRACT

Protein kinases Aurora A, B, and C play essential roles during mitosis and cell division, are frequently elevated in cancer, and represent attractive targets for therapeutic intervention. TAK-901 is an investigational, multitargeted Aurora B kinase inhibitor derived from a novel azacarboline kinase hinge-binder chemotype. TAK-901 exhibited time-dependent, tight-binding inhibition of Aurora B, but not Aurora A. Consistent with Aurora B inhibition, TAK-901 suppressed cellular histone H3 phosphorylation and induced polyploidy. In various human cancer cell lines, TAK-901 inhibited cell proliferation with effective concentration values from 40 to 500 nmol/L. Examination of a broad panel of kinases in biochemical assays revealed inhibition of multiple kinases. However, TAK-901 potently inhibited only a few kinases other than Aurora B in intact cells, including FLT3 and FGFR2. In rodent xenografts, TAK-901 exhibited potent activity against multiple human solid tumor types, and complete regression was observed in the ovarian cancer A2780 model. TAK-901 also displayed potent activity against several leukemia models. In vivo biomarker studies showed that TAK-901 induced pharmacodynamic responses consistent with Aurora B inhibition and correlating with retention of TAK-901 in tumor tissue. These preclinical data highlight the therapeutic potential of TAK-901, which has entered phase I clinical trials in patients within a diverse range of cancers.


Subject(s)
Carbolines/pharmacology , Protein Kinase Inhibitors/pharmacology , Protein Serine-Threonine Kinases/antagonists & inhibitors , Sulfones/pharmacology , Animals , Antineoplastic Agents/chemistry , Antineoplastic Agents/pharmacology , Aurora Kinase A , Aurora Kinase B , Aurora Kinases , Biomarkers , Carbolines/chemistry , Cell Proliferation/drug effects , Dose-Response Relationship, Drug , Enzyme Activation/drug effects , Histones/metabolism , Humans , Kinetics , Mice , Phosphorylation/drug effects , Protein Binding , Protein Kinase Inhibitors/chemistry , Protein Serine-Threonine Kinases/metabolism , Rats , Sulfones/chemistry , Xenograft Model Antitumor Assays
17.
Nihon Jibiinkoka Gakkai Kaiho ; 115(5): 534-9, 2012 May.
Article in Japanese | MEDLINE | ID: mdl-22686064

ABSTRACT

Vertigo is one of the usual menopausal symptoms. We have often examined some women under the complaint of vertigo related with the menopause. We diagnosed each disease based on neuro-otological examinations and investigated the characteristics of menopausal-associated vertigo. We studied 413 women aged 40-59 years old who complained of vertigo. There were 73 women with menopause symptoms (14 women introduced from the gynecologist in our medical center, 18 women had undergone treatment at another female clinic, and 41 women visited an otorhinolaryngologist first) compared with 340 women without menopause symptoms. In the menopause group, 41 (56.2%) cases were diagnosed as having benign paroxysmal positional vertigo (BPPV), 13 (17.8%) cases had Meniere's disease, sudden deafness with vertigo accounted 2 cases, one was an acoustic tumor, and so on. The percentage of patients with BPPV was almost same ratio between the menopause group (56.2%) and the non-menopause group (52.9%). The percentage of patients with Meniere's disease was higher markedly in the menopausal group (17.8%). than the non-menopause group (9.7%). Menopausal symptoms are caused not only by hot flashes related to a lack of estrogen but also by psychological factors. The onset of Meniere's disease can also be influenced by psychological factors. As for the diagnosis of Meniere's disease, we supposed the reason for the higher percentage in the menopausal group was its relationship with psychological factors. We could diagnose and treat some menopausal women with vertigo. We believe that joint consultation with a gynecologist and otorhinolaryngologist would be necessary to ensure an optimum quality of life for such patients.


Subject(s)
Menopause , Vertigo , Female , Humans , Middle Aged , Vertigo/diagnosis , Vertigo/therapy
18.
Neurol Sci ; 33(1): 129-32, 2012 Feb.
Article in English | MEDLINE | ID: mdl-21479608

ABSTRACT

Isolated vertigo is rare in lateral medullary infarction. We described early diagnostic challenges in such cases by a neuro-otological approach. We report a 56-year-old man who developed a lateral medullary infarction that presented as isolated vertigo. Before the day 4 from disease onset when diffusion-weighted magnetic resonance imaging (MRI) became positive, this patient showed unilateral loss of visual suppression, a central type of vestibular dysfunction. Since MRI abnormalities may not appear in the early few days from disease onset, unilateral loss of visual suppression might become an important diagnostic option for isolated vertigo due to a lateral medullary infarction. This finding is presumably relevant to the inferior olive lesion.


Subject(s)
Brain Stem Infarctions/complications , Medulla Oblongata/pathology , Vertigo/etiology , Diffusion Magnetic Resonance Imaging , Humans , Male , Middle Aged
19.
Nihon Jibiinkoka Gakkai Kaiho ; 114(11): 869-74, 2011 Nov.
Article in Japanese | MEDLINE | ID: mdl-22250405

ABSTRACT

We treated 1145 patients diagnosed as having benign paroxysmal postural vertigo at the Toho University Medical Center Sakura Hospital from August 2007 to July 2009 by the exercise therapy developed by us. The most advantageous characteristic of our method is that patients can perform the exercises themselves at their own pace in their homes, even if the affected side cannot be identified and/or the patients have any orthopedic cervical and/or spinal problems. In 80.7% and 91.7% of the patients in our case series, the vertigo was no longer present at one and three months, respectively. In addition, the vertigo disappeared within two weeks in the patients who were examined within one week of the start of the symptom. The longer the period between the onset of vertigo and the hospital visit, the longer the period needed for control of the symptom.


Subject(s)
Exercise Therapy/methods , Vertigo/therapy , Adolescent , Adult , Aged , Aged, 80 and over , Child , Female , Humans , Male , Middle Aged , Time Factors , Young Adult
20.
Langmuir ; 26(24): 18676-80, 2010 Dec 21.
Article in English | MEDLINE | ID: mdl-21086996

ABSTRACT

Colloidosomes have attracted great interest in recent years because of the capability of storage and delivery of useful materials in various fields. In this article, a novel technique for formation of colloidosomes at room temperature suitable for encapsulation of biomaterials was examined. We demonstrate the formation of colloidosomes of 18.0 µm in size at room temperature by adding a small amount of ethanol into the continuous phase of sunflower oil. Poly(methyl methacrylate-co-butyl acrylate) latex particles of 185 nm in size, used in this study, were found to aggregate when ethanol was added to their suspension. We suggest that the shell of the water-core emulsions was locked by the aggregation of latex particles due to the diffusion of ethanol into the aqueous latex suspension.


Subject(s)
Latex/chemistry , Temperature , Water/chemistry , Ethanol/chemistry , Microscopy , Suspensions
SELECTION OF CITATIONS
SEARCH DETAIL
...