Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 10 de 10
Filter
1.
J Pathol ; 211(5): 524-531, 2007 Apr.
Article in English | MEDLINE | ID: mdl-17323425

ABSTRACT

The Birt-Hogg-Dubé (BHD) gene is responsible for BHD syndrome, a rare autosomal dominant disease, characterized by benign hair follicle tumours, spontaneous pneumothorax and renal neoplasms with diverse histology. To elucidate its involvement in the development of renal neoplasms, we examined a total of 100 sporadic renal tumours with various histological subtypes for BHD mutation by SSCP-sequencing analyses. We found one germline insertion mutation in the C8 hotspot of exon 11 (c.1733insC), which is known to have a strong association with renal tumour occurrence. The germline-mutated patient suffered from solitary renal cell carcinoma (RCC) but did not have any other BHD manifestations or family history. The tumour revealed heterogeneous cytomorphology, mainly a mixture of eosinophilic and focally clear cells with tubulopapillary architecture. In this tumour, both BHD alleles were inactivated by germline mutation concomitant with loss of heterozygosity, and the amount of BHD mRNA detected by real-time quantitative PCR (RQ-PCR) was very low. Renal tumour subtype/nephron segment-specific gene expression detected by RQ-PCR demonstrated that the tumour expressed relatively high amounts of alpha-methylacyl-CoA racemase (AMACR) and the KIT oncogene, but relatively low amounts of carbonic anhydrase IX (CA9), aquaporin 1 (AQP1), claudin 7 (CLDN7), parvalbumin (PVALB), chloride channel Kb (CLCNKB) and 11-beta-hydroxysteroid dehydrogenase 2 (HSD11B2), suggesting diverse mRNA signatures. Further clustering analysis of 88 renal tumours based on expression of these eight genes sub-classified the tumour as close to oncocytomas and chromophobe RCCs, which are considered distal nephron-associated tumours. These data suggest that somatic mutation of BHD is relatively rare in Japanese patients. The BHD-mutated RCC identified in this study, which exhibits heterogeneous biological features in both morphology and gene expression signatures, seems to deviate from our current understanding of renal tumour classification.


Subject(s)
Carcinoma, Renal Cell/genetics , Kidney Neoplasms/genetics , Neoplasm Proteins/genetics , Proteins/genetics , Proto-Oncogene Proteins/genetics , Tumor Suppressor Proteins/genetics , Carcinoma, Renal Cell/pathology , Cluster Analysis , Eosinophilia/genetics , Eosinophilia/pathology , Gene Expression Regulation, Neoplastic/genetics , Genes, Tumor Suppressor/physiology , Germ-Line Mutation/genetics , Hair Diseases/genetics , Hair Diseases/pathology , Hair Follicle/pathology , Humans , Kidney Neoplasms/pathology , Loss of Heterozygosity/genetics , Mutation/genetics , Pneumothorax/genetics , Pneumothorax/pathology , Polymerase Chain Reaction/methods , Polymorphism, Single-Stranded Conformational , Syndrome
2.
Mol Cell Biol ; 21(17): 5857-68, 2001 Sep.
Article in English | MEDLINE | ID: mdl-11486025

ABSTRACT

beta-Catenin is an oncogenic protein involved in regulation of cell-cell adhesion and gene expression. Accumulation of cellular beta-catenin occurs in many types of human cancers. Four mechanisms are known to cause increases in beta-catenin: mutations of beta-catenin, adenomatous polyposis coli, or axin genes and activation of Wnt signaling. We report a new cause of beta-catenin accumulation involving oncogenic mutants of RON and MET receptor tyrosine kinases (RTKs). Cells transfected with oncogenic RON or MET were characterized by beta-catenin tyrosine phosphorylation and accumulation; constitutive activation of a Tcf transcriptional factor; and increased levels of beta-catenin/Tcf target oncogene proteins c-myc and cyclin D1. Interference with the beta-catenin pathway reduced the transforming potential of mutated RON and MET. Activation of beta-catenin by oncogenic RON and MET constitutes a new pathway, which might lead to cell transformation by these and other mutant growth factor RTKs.


Subject(s)
Cytoskeletal Proteins/metabolism , Proto-Oncogene Proteins c-met/metabolism , Receptor Protein-Tyrosine Kinases/metabolism , Receptors, Cell Surface/metabolism , Repressor Proteins , Signal Transduction , Trans-Activators , 3T3 Cells , Animals , Axin Protein , Calcium-Calmodulin-Dependent Protein Kinases/metabolism , Cell Line , Cell Transformation, Neoplastic , Cyclin D1/biosynthesis , Dogs , Glycogen Synthase Kinase 3 , Mice , Mutagenesis, Site-Directed , Phosphorylation , Proteins/metabolism , Proto-Oncogene Proteins c-met/genetics , Proto-Oncogene Proteins c-myc/biosynthesis , Proto-Oncogene Proteins c-myc/genetics , Receptor Protein-Tyrosine Kinases/genetics , Receptors, Cell Surface/genetics , TCF Transcription Factors , Transcription Factor 7-Like 2 Protein , Transcription Factors/genetics , Transcriptional Activation , Tyrosine/metabolism , beta Catenin
3.
Proteins ; 44(1): 32-43, 2001 Jul 01.
Article in English | MEDLINE | ID: mdl-11354004

ABSTRACT

Missense mutations in the tyrosine kinase domain of the MET proto-oncogene occur in selected cases of papillary renal carcinoma. In biochemical and biological assays, these mutations produced constitutive activation of the MET kinase and led to tumor formation in nude mice. Some mutations caused transformation of NIH 3T3 cells. To elucidate the mechanism of ligand-independent MET kinase activation by point mutations, we constructed several 3D models of the wild-type and mutated MET catalytic core domains. Analysis of these structures showed that some mutations (e.g., V1110I, Y1248H/D/C, M1268T) directly alter contacts between residues from the activation loop in its inhibitory conformation and those from the main body of the catalytic domain; others (e.g., M1149T, L1213V) increase flexibility at the critical points of the tertiary structure and facilitate subdomain movements. Mutation D1246N plays a role in stabilizing the active form of the enzyme. Mutation M1268T affects the S+1 and S+3 substrate-binding pockets. Models implicate that although these changes do not compromise the affinity toward the C-terminal autophosphorylation site of the MET protein, they allow for binding of the substrate for the c-Abl tyrosine kinase. We provide biochemical data supporting this observation. Mutation L1213V affects the conformation of Tyr1212 in the active form of MET. Several somatic mutations are clustered at the surface of the catalytic domain in close vicinity of the probable location of the MET C-terminal docking site for cytoplasmic effectors.


Subject(s)
Point Mutation/genetics , Protein-Tyrosine Kinases/metabolism , Proto-Oncogene Proteins , Proto-Oncogenes/genetics , Receptors, Growth Factor , Trans-Activators/genetics , Trans-Activators/metabolism , Catalytic Domain/genetics , Catalytic Domain/physiology , Enzyme Activation/genetics , Enzyme Activation/physiology , Ligands , Models, Molecular , Protein Structure, Tertiary/physiology , Proto-Oncogene Mas , Proto-Oncogene Proteins c-met , Sequence Alignment , Sequence Homology , Substrate Specificity/physiology
4.
Nihon Rinsho ; 59(1): 104-9, 2001 Jan.
Article in Japanese | MEDLINE | ID: mdl-11197838

ABSTRACT

The oncogenic mechanisms of renal cell carcinoma(RCC) are becoming elucidated with recent advances in molecular biology. von Hipple-Lindau disease(VHL) tumor suppressor gene is mutated and inactivated frequently in clear cell type RCCs. The VHL protein forms a complex which shows a ubiquitin ligase activity. The lost of the ubiquitin ligase activity of VHL protein may be a key step for clear cell tumorigenesis. Papillary renal cell carcinomas are caused by activating mutation in the tyrosine kinase domain of the MET gene. This tumorigenic pathway is regulated by c-Src. Immunogene therapies have been started for the patients with advanced RCC. The information based on microarray and Serial Analysis of Gene Expression(SAGE) will provide novel diagnosis and therapy which focus on the tumorigenic mechanism of RCC in the near future.


Subject(s)
Carcinoma, Renal Cell/genetics , Kidney Neoplasms/genetics , Ligases , Tumor Suppressor Proteins , Ubiquitin-Protein Ligases , Animals , Carcinoma, Renal Cell/therapy , Gene Expression Profiling , Genes, Suppressor/genetics , Genes, src , Genetic Therapy , Humans , Kidney Neoplasms/therapy , Mutation , Protein-Tyrosine Kinases/genetics , Proteins/genetics , Proto-Oncogene Proteins c-met/genetics , Von Hippel-Lindau Tumor Suppressor Protein , von Hippel-Lindau Disease/genetics
5.
Oncogene ; 19(26): 2996-3002, 2000 Jun 15.
Article in English | MEDLINE | ID: mdl-10871851

ABSTRACT

We recently described germline and somatic mutations in the MET gene associated with papillary renal carcinoma type 1. MET mutation M1268T was located in a codon highly conserved among receptor tyrosine kinases, and homologous to the codon mutated in multiple endocrine neoplasia type 2B, and many cases of sporadic medullary carcinoma of the thyroid gland (Ret M918T). Ret M918T and MET M1268T have previously been shown to be highly active in mouse NIH3T3 transformation assays, and to change the substrate specificity of the kinase. We studied the mechanism of transformation mediated by MET M1268T by analysing a clone, F4, derived from NIH3T3 cells transformed by MET M1268T. In contrast to NIH3T3 cells, F4 cells grew in suspension in tissue culture, and rapidly formed tumors in nude mice. We found that c-Src was constitutively bound to MET proteins in F4 cells, and that Src kinase activity was elevated. Transfection of dominant negative Src constructs into F4 cells eliminated the ability of F4 cells to grow in suspension culture and retarded the growth of F4 cells in vivo. The ability of transfected dominant negative Src constructs to inhibit the growth of F4 cells correlated with the inhibition of phosphorylation of paxillin and focal adhesion kinase. Transfection of dominant negative Src constructs into F4 cells had no effect on Grb2 binding or PLC gamma phosphorylation. The results suggest that c-Src participates in the tumorigenic phenotype induced in NIH3T3 cells by MET M1268T by signaling through focal adhesion kinase and paxillin. Oncogene (2000).


Subject(s)
Cell Transformation, Neoplastic/genetics , Genes, Dominant , Oncogene Protein pp60(v-src)/genetics , Proto-Oncogene Proteins c-met/genetics , 3T3 Cells , Animals , Blood , Cell Division/genetics , Cytoskeletal Proteins/metabolism , Focal Adhesion Kinase 1 , Focal Adhesion Protein-Tyrosine Kinases , Isoenzymes/metabolism , Mice , Mitogen-Activated Protein Kinases/metabolism , Paxillin , Phospholipase C gamma , Phosphoproteins/metabolism , Phosphorylation , Protein-Tyrosine Kinases/metabolism , Transfection , Type C Phospholipases/metabolism
6.
Oncogene ; 18(14): 2343-50, 1999 Apr 08.
Article in English | MEDLINE | ID: mdl-10327054

ABSTRACT

Hereditary papillary renal carcinoma (HPRC) is characterized by multiple, bilateral papillary renal carcinomas. Previously, we demonstrated missense mutations in the tyrosine kinase domain of the MET proto-oncogene in HPRC and a subset of sporadic papillary renal carcinomas. In this study, we screened a large panel of sporadic papillary renal carcinomas and various solid tumors for mutations in the MET proto-oncogene. Summarizing these and previous results, mutations of the MET proto-oncogene were detected in 17/129 sporadic papillary renal carcinomas but not in other solid tumors. We detected five novel missense mutations; three of five mutations were located in the ATP-binding region of the tyrosine kinase domain of MET. One novel mutation in MET, V1110I, was located at a codon homologous to an activating mutation in the c-erbB proto-oncogene. These mutations caused constitutive phosphorylation of MET when transfected into NIH3T3 cells. Molecular modeling studies suggest that these activating mutations interfere with the intrasteric mechanism of tyrosine kinase autoinhibition and facilitate transition to the active form of the MET kinase. The low frequency of MET mutations in noninherited papillary renal carcinomas (PRC) suggests that noninherited PRC may develop by a different mechanism than hereditary papillary renal carcinoma.


Subject(s)
Carcinoma, Papillary/genetics , DNA, Neoplasm/genetics , Kidney Neoplasms/genetics , Neoplasm Proteins/genetics , Point Mutation , Proto-Oncogene Proteins c-met/genetics , Proto-Oncogenes , 3T3 Cells/metabolism , Adenoma/genetics , Adenoma/metabolism , Adenosine Triphosphate/metabolism , Amino Acid Sequence , Animals , Binding Sites , Cell Transformation, Neoplastic/genetics , Codon/genetics , DNA Mutational Analysis , Humans , Mice , Models, Molecular , Molecular Sequence Data , Mutagenesis, Site-Directed , Neoplasm Proteins/chemistry , Neoplasm Proteins/metabolism , Neoplastic Syndromes, Hereditary/genetics , Phosphorylation , Protein Conformation , Protein Processing, Post-Translational/genetics , Proto-Oncogene Mas , Proto-Oncogene Proteins c-met/chemistry , Proto-Oncogene Proteins c-met/metabolism , Sequence Alignment , Sequence Homology, Amino Acid , Transfection
7.
Proc Natl Acad Sci U S A ; 94(21): 11445-50, 1997 Oct 14.
Article in English | MEDLINE | ID: mdl-9326629

ABSTRACT

Recently, mutations in the Met tyrosine kinase receptor have been identified in both hereditary and sporadic forms of papillary renal carcinoma. We have introduced the corresponding mutations into the met cDNA and examined the effect of each mutation in biochemical and biological assays. We find that the Met mutants exhibit increased levels of tyrosine phosphorylation and enhanced kinase activity toward an exogenous substrate when compared with wild-type Met. Moreover, NIH 3T3 cells expressing mutant Met molecules form foci in vitro and are tumorigenic in nude mice. Enzymatic and biological differences were evident among the various mutants examined, and the somatic mutations were generally more active than those of germ-line origin. A strong correlation between the enzymatic and biological activity of the mutants was observed, indicating that tumorigenesis by Met is quantitatively related to its level of activation. These results demonstrate that the Met mutants originally identified in human papillary renal carcinoma are oncogenic and thus are likely to play a determinant role in this disease, and these results raise the possibility that activating Met mutations also may contribute to other human malignancies.


Subject(s)
Carcinoma, Papillary/genetics , Cell Transformation, Neoplastic , Kidney Neoplasms/genetics , Neoplasms, Experimental/genetics , Point Mutation , Proto-Oncogene Proteins c-met/genetics , Proto-Oncogene Proteins c-met/metabolism , 3T3 Cells , Amino Acid Sequence , Animals , Female , Humans , Mice , Mice, Nude , Molecular Sequence Data , Neoplasms, Experimental/pathology , Protein-Tyrosine Kinases/metabolism , Proto-Oncogene Proteins c-met/chemistry , Proto-Oncogenes , Recombinant Proteins/chemistry , Recombinant Proteins/metabolism , Sequence Alignment , Sequence Homology, Amino Acid , Transfection
8.
Hinyokika Kiyo ; 42(9): 695-7, 1996 Sep.
Article in Japanese | MEDLINE | ID: mdl-8918673

ABSTRACT

We report a case of aphallia in a male neonate. The phallus was completely absent. The urethral meatus was located between the well developed bifid scrotum containing normal testes. Voiding cystourethrography revealed grade II VUR on the right side. The karyotype was 46XY. Other urogenital anomalies were not detected. Bilateral orchiectomy was performed at 2 months of age. The sex assignment and management of aphallia were discussed.


Subject(s)
Orchiectomy , Penis/abnormalities , Scrotum/surgery , Humans , Infant, Newborn , Karyotyping , Male
9.
Biochem Biophys Res Commun ; 222(1): 95-100, 1996 May 06.
Article in English | MEDLINE | ID: mdl-8630081

ABSTRACT

Introduction of a reporter gene containing E2F binding sites linked to the luciferase gene permitted us to detect transient cellular E2F activity in late G1 phase rat 3Y1 fibroblasts. Overexpression of three major protein kinase C (PKC) isozymes expressed in 3Y1 cells caused differing effects on E2F activity depending on the isozymes overexpressed. Overexpression of PKC alpha inhibited E2F activity while the overexpression of PKC delta or PKC epsilon enhanced it, suggesting that these PKC isozymes play different roles in the regulation of E2F activity. Consistent with previous findings that the activation of PKC by TPA in late G1 phase results in the inhibition of DNA synthesis (Huang, C., and Ives, H.E., 1987, Nature 329, 849-850), the addition of TPA in late G1 phase specifically inhibited E2F activity. Overexpression of PKC isozymes resulted in an enhancement of the TPA-induced inhibition of E2F in late G1 phase. This enhancement was observed for all three PKC isozymes examined, suggesting that these PKC isozymes all are potent mediators of the TPA-induced inhibition of E2F activity in late G1 phase.


Subject(s)
Carrier Proteins , Cell Cycle Proteins , DNA-Binding Proteins , G1 Phase , Isoenzymes/metabolism , Protein Kinase C/metabolism , Transcription Factors/metabolism , Animals , Base Sequence , Cells, Cultured , E2F Transcription Factors , Enzyme Activation , Molecular Sequence Data , Oligodeoxyribonucleotides/chemistry , Protein Kinase C-alpha , Protein Kinase C-delta , Protein Kinase C-epsilon , Rats , Retinoblastoma-Binding Protein 1 , Tetradecanoylphorbol Acetate/pharmacology , Transcription Factor DP1
10.
Hinyokika Kiyo ; 42(2): 101-4, 1996 Feb.
Article in Japanese | MEDLINE | ID: mdl-8712082

ABSTRACT

Twenty-three cases of testicular tumor (10; malignant, 13; benign) in childhood are reported. The age at diagnosis was between 3 months old and 8 years old. Twelve patients visited the clinic within a month of first appearance of symptoms. All but one patient received high orchiectomy. One patient had resection of tumor because of its benign property. Eight of the 10 patients with malignancies received 30-50Gy of retroperitoneal radiation, including one patient (stage IIa) with retroperitoneal lymph node dissection. Two patients (stage I and IIa) with post-operative metastasis in lungs, brain and mediastinal lymph nodes were treated with chemotherapy repeatedly, but they died. Our latest therapy is; 1) high orchiectomy recommended for benign and stage I malignant testicular tumors in childhood, 2) retroperitoneal radiation and/or lymph node dissection limited for patients with stage II malignancy, and 3) Systemic chemotherapy for stage III malignant tumors. At least three years of follow up would be needed. Those who received radiation or chemotherapy should be followed longer.


Subject(s)
Endodermal Sinus Tumor/therapy , Teratoma/therapy , Testicular Neoplasms/therapy , Age of Onset , Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Child , Child, Preschool , Combined Modality Therapy , Endodermal Sinus Tumor/pathology , Follow-Up Studies , Humans , Infant , Lymph Node Excision , Male , Neoplasm Metastasis , Neoplasm Staging , Orchiectomy , Radiotherapy , Teratoma/pathology , Testicular Neoplasms/pathology
SELECTION OF CITATIONS
SEARCH DETAIL
...