Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 4 de 4
Filter
Add more filters










Database
Language
Publication year range
1.
Jpn J Clin Oncol ; 44(4): 374-8, 2014 Apr.
Article in English | MEDLINE | ID: mdl-24558126

ABSTRACT

A 72-year-old male visited a local hospital on presentation of melena. Colonoscopy revealed a protruded lesion in the ascending colon, and computed tomography revealed a 20 cm retroperitoneal tumor. Biopsy failed to provide a definitive diagnosis of the colonic lesion. He was diagnosed as having a retroperitoneal liposarcoma and an ascending colon tumor using computed tomography, and referred to our hospital. Biopsy of the ascending colon lesion showed spindle cells with fibrosis. On immunohistochemical staining, tumor cells were positive for cyclin-dependent kinase 4 and murine double minute 2, and the lesion was diagnosed as a well-differentiated or dedifferentiated liposarcoma. The retroperitoneal liposarcoma, which had infiltrated the ascending colon, was resected along with the right colon and the right kidney. Macroscopically, the tumor had infiltrated the ascending colon, forming a multinodular solid mass in the lumen and the right kidney. Microscopic finding of the main tumor revealed a well-differentiated liposarcoma, and that of the colonic lesion revealed a dedifferentiated liposarcoma with nuclei of different sizes and shapes and increased spindle cell morphology. The right kidney and ureter were surrounded by tumor cells but were not infiltrated, and there was no lymph node involvement. The diagnosis of retroperitoneal liposarcoma is often difficult because symptoms appear only after the tumor becomes very large. Some retroperitoneal liposarcomas are found on computed tomography by chance. The clinical course of this case was very rare because of the presentation of melena as the first symptom and the detection of an invasive mass in the ascending colon using colonoscopy.


Subject(s)
Colectomy , Colonic Neoplasms/secondary , Colonic Neoplasms/surgery , Colonoscopy , Liposarcoma/pathology , Liposarcoma/surgery , Nephrectomy , Retroperitoneal Neoplasms/pathology , Retroperitoneal Neoplasms/surgery , Aged , Biomarkers, Tumor/isolation & purification , Colonic Neoplasms/chemistry , Colonic Neoplasms/complications , Colonic Neoplasms/diagnosis , Cyclin-Dependent Kinase 4/isolation & purification , Humans , Immunohistochemistry , Liposarcoma/chemistry , Liposarcoma/diagnosis , Male , Melena/etiology , Proto-Oncogene Proteins c-mdm2/isolation & purification , Retroperitoneal Neoplasms/chemistry , Retroperitoneal Neoplasms/diagnosis , Tomography, X-Ray Computed
2.
Biochemistry ; 48(19): 4050-62, 2009 May 19.
Article in English | MEDLINE | ID: mdl-19320462

ABSTRACT

Ankyrin repeat (AR) proteins are one of the most abundant repeat protein classes in nature, and they are involved in numerous physiological processes through mediating protein/protein interactions. The repetitive and modular architecture of these AR proteins may lead to biochemical and biophysical properties distinct from those of globular proteins. It has been demonstrated that like most globular proteins, AR proteins exhibit a two-state, cooperative transition in chemical- and heat-induced unfolding. However, the biophysical characteristics underlying such cooperative unfolding remain to be further investigated. In the present study, we evaluated the conformational stability of a group of cyclin-dependent kinase (CDK) 4-interacting AR proteins, P16, P18, IkappaBalpha, gankyrin, and their truncated mutants under different conditions, including the presence of denaturants, temperature, and pH. Our results showed that the first four N-terminal ARs are required to form a potent and stable CDK4 modulator. Moreover, in spite of their similarities in skeleton structure, CDK4 binding, and cooperative unfolding, P16, P18, IkappaBalpha, and gankyrin exhibited considerably different biophysical properties with regard to the conformational stability, and these differences mainly resulted from the discrepancies in the primary sequence of the relatively conserved AR motifs. Our results also demonstrated that these sequence discrepancies are able to influence the function of AR proteins to a certain extent. Overall, our results provide important insights into understanding the biophysical properties of AR proteins.


Subject(s)
Ankyrin Repeat/genetics , Cyclin-Dependent Kinase 4/metabolism , Protein Conformation , Amino Acid Motifs , Amino Acid Sequence , Conserved Sequence , Cyclin-Dependent Kinase 2/genetics , Cyclin-Dependent Kinase 2/isolation & purification , Cyclin-Dependent Kinase 2/metabolism , Cyclin-Dependent Kinase 4/analysis , Cyclin-Dependent Kinase 4/chemistry , Cyclin-Dependent Kinase 4/genetics , Cyclin-Dependent Kinase 4/isolation & purification , Gadolinium/pharmacology , Glutathione Transferase/metabolism , Histidine/chemistry , Histidine/metabolism , Humans , Hydrogen-Ion Concentration , Hydrophobic and Hydrophilic Interactions , Models, Biological , Models, Molecular , Molecular Sequence Data , Protein Denaturation/drug effects , Protein Structure, Secondary , Protein Structure, Tertiary , Recombinant Fusion Proteins/chemistry , Recombinant Fusion Proteins/isolation & purification , Recombinant Fusion Proteins/metabolism , Temperature
3.
Mol Cell ; 23(5): 697-707, 2006 Sep 01.
Article in English | MEDLINE | ID: mdl-16949366

ABSTRACT

Activation of many protein kinases depends on their interaction with the Hsp90 molecular chaperone system. Recruitment of protein kinase clients to the Hsp90 chaperone system is mediated by the cochaperone adaptor protein Cdc37, which acts as a scaffold, simultaneously binding protein kinases and Hsp90. We have now expressed and purified an Hsp90-Cdc37-Cdk4 complex, defined its stoichiometry, and determined its 3D structure by single-particle electron microscopy. Comparison with the crystal structure of Hsp90 allows us to identify the locations of Cdc37 and Cdk4 in the complex and suggests a mechanism by which conformational changes in the kinase are coupled to the Hsp90 ATPase cycle.


Subject(s)
Cell Cycle Proteins/chemistry , Cell Cycle Proteins/ultrastructure , Chaperonins/chemistry , Chaperonins/ultrastructure , Cyclin-Dependent Kinase 4/chemistry , Cyclin-Dependent Kinase 4/ultrastructure , HSP90 Heat-Shock Proteins/chemistry , HSP90 Heat-Shock Proteins/ultrastructure , Cell Cycle Proteins/isolation & purification , Chaperonins/isolation & purification , Cyclin-Dependent Kinase 4/isolation & purification , HSP90 Heat-Shock Proteins/isolation & purification , Humans , Microscopy, Electron , Models, Molecular , Multiprotein Complexes/chemistry , Multiprotein Complexes/isolation & purification , Multiprotein Complexes/ultrastructure , Protein Binding
4.
J Pharm Biomed Anal ; 39(3-4): 811-4, 2005 Sep 15.
Article in English | MEDLINE | ID: mdl-15955655

ABSTRACT

Protocols to assess kinase activity generally include radioactive methods, fluorescent polarization technology and the use of specific antibodies. Here, a simple, effective, non radioactive method to measure kinase activity of immunoprecipitated proteins is described. Cdk4, a cell cycle dependent enzyme, was immunoprecipitated from whole cell extracts and used in kinase reactions. This system has been developed taking advantage of the kinase-Glo reagent (Promega), based on ATP depletion technology, but with a wider range of applications. The original aim of the commercial kit is the evaluation of kinase activity of highly purified enzymes, while this system enabled the evaluation of native kinases, retrieved by immunoprecipitation. This method was highly homogeneous and did not require any kind of separation or purification as well. Moreover, it was suitable for basic research and may be useful for low-medium throughput pharmaceutical screening of chemical libraries.


Subject(s)
Biochemistry/methods , Cyclin-Dependent Kinase 4/analysis , Cyclin-Dependent Kinase 4/isolation & purification , Drug Evaluation, Preclinical/methods , Luminescence , Technology, Pharmaceutical/methods , Adenosine Triphosphate/chemistry , Cell Cycle , Chemistry, Pharmaceutical/methods , Drug Industry/methods , Enzymes/analysis , Fluorescence Polarization Immunoassay/methods , HeLa Cells , Humans , Immunoblotting , Immunoprecipitation , Indoles/analysis , Models, Statistical , Oximes/analysis , Phosphorylation , Time Factors
SELECTION OF CITATIONS
SEARCH DETAIL
...