RESUMO
Tumor suppressor and upstream master kinase Liver kinase B1 (LKB1) plays a significant role in suppressing cancer growth and metastatic progression. We show that low-LKB1 expression significantly correlates with poor survival outcome in breast cancer. In line with this observation, loss-of-LKB1 rendered breast cancer cells highly migratory and invasive, attaining cancer stem cell-like phenotype. Accordingly, LKB1-null breast cancer cells exhibited an increased ability to form mammospheres and elevated expression of pluripotency-factors (Oct4, Nanog and Sox2), properties also observed in spontaneous tumors in Lkb1-/- mice. Conversely, LKB1-overexpression in LKB1-null cells abrogated invasion, migration and mammosphere-formation. Honokiol (HNK), a bioactive molecule from Magnolia grandiflora increased LKB1 expression, inhibited individual cell-motility and abrogated the stem-like phenotype of breast cancer cells by reducing the formation of mammosphere, expression of pluripotency-factors and aldehyde dehydrogenase activity. LKB1, and its substrate, AMP-dependent protein kinase (AMPK) are important for HNK-mediated inhibition of pluripotency factors since LKB1-silencing and AMPK-inhibition abrogated, while LKB1-overexpression and AMPK-activation potentiated HNK's effects. Mechanistic studies showed that HNK inhibited Stat3-phosphorylation/activation in an LKB1-dependent manner, preventing its recruitment to canonical binding-sites in the promoters of Nanog, Oct4 and Sox2. Thus, inhibition of the coactivation-function of Stat3 resulted in suppression of expression of pluripotency factors. Further, we showed that HNK inhibited breast tumorigenesis in mice in an LKB1-dependent manner. Molecular analyses of HNK-treated xenografts corroborated our in vitro mechanistic findings. Collectively, these results present the first in vitro and in vivo evidence to support crosstalk between LKB1, Stat3 and pluripotency factors in breast cancer and effective anticancer modulation of this axis with HNK treatment.
Assuntos
Compostos de Bifenilo/administração & dosagem , Neoplasias da Mama/tratamento farmacológico , Lignanas/administração & dosagem , Proteínas Serina-Treonina Quinases/genética , Fator de Transcrição STAT3/genética , Quinases Proteína-Quinases Ativadas por AMP , Animais , Neoplasias da Mama/genética , Neoplasias da Mama/patologia , Linhagem Celular Tumoral , Movimento Celular/genética , Transformação Celular Neoplásica , Feminino , Humanos , Camundongos , Células-Tronco Neoplásicas/efeitos dos fármacos , Células-Tronco Neoplásicas/patologia , Proteínas Serina-Treonina Quinases/biossíntese , Fator de Transcrição STAT3/antagonistas & inibidores , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
Multiple myeloma (MM) remains an incurable malignancy due, in part, to the influence of the bone marrow microenvironment on survival and drug response. Identification of microenvironment-specific survival signaling determinants is critical for the rational design of therapy and elimination of MM. Previously, we have shown that collaborative signaling between ß1 integrin-mediated adhesion to fibronectin and interleukin-6 confers a more malignant phenotype via amplification of signal transducer and activator of transcription 3 (STAT3) activation. Further characterization of the events modulated under these conditions with quantitative phosphotyrosine profiling identified 193 differentially phosphorylated peptides. Seventy-seven phosphorylations were upregulated upon adhesion, including PYK2/FAK2, Paxillin, CASL and p130CAS consistent with focal adhesion (FA) formation. We hypothesized that the collaborative signaling between ß1 integrin and gp130 (IL-6 beta receptor, IL-6 signal transducer) was mediated by FA formation and proline-rich tyrosine kinase 2 (PYK2) activity. Both pharmacological and molecular targeting of PYK2 attenuated the amplification of STAT3 phosphorylation under co-stimulatory conditions. Co-culture of MM cells with patient bone marrow stromal cells (BMSC) showed similar ß1 integrin-specific enhancement of PYK2 and STAT3 signaling. Molecular and pharmacological targeting of PYK2 specifically induced cell death and reduced clonogenic growth in BMSC-adherent myeloma cell lines, aldehyde dehydrogenase-positive MM cancer stem cells and patient specimens. Finally, PYK2 inhibition similarly attenuated MM progression in vivo. These data identify a novel PYK2-mediated survival pathway in MM cells and MM cancer stem cells within the context of microenvironmental cues, providing preclinical support for the use of the clinical stage FAK/PYK2 inhibitors for treatment of MM, especially in a minimal residual disease setting.
Assuntos
Quinase 2 de Adesão Focal/metabolismo , Mieloma Múltiplo/patologia , Animais , Morte Celular/fisiologia , Linhagem Celular Tumoral , Feminino , Quinase 2 de Adesão Focal/antagonistas & inibidores , Humanos , Interleucina-6/metabolismo , Janus Quinase 1/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Terapia de Alvo Molecular , Mieloma Múltiplo/tratamento farmacológico , Mieloma Múltiplo/genética , Mieloma Múltiplo/metabolismo , Fosforilação , Inibidores de Proteínas Quinases/farmacologia , Fator de Transcrição STAT3/metabolismo , Transdução de Sinais , Microambiente TumoralAssuntos
Carcinógenos/farmacologia , Transformação Celular Neoplásica/efeitos dos fármacos , Transformação Celular Neoplásica/patologia , Modelos Animais de Doenças , Mieloma Múltiplo/metabolismo , Mieloma Múltiplo/patologia , Sindecana-1/metabolismo , Animais , Apoptose , Ensaio de Unidades Formadoras de Colônias , Citometria de Fluxo , Camundongos , Camundongos Endogâmicos C57BL , Células Tumorais CultivadasRESUMO
BACKGROUND: Rituximab may improve transplant outcomes but may delay immunologic recovery. PATIENTS AND METHODS: Seventy-seven patients with low-grade or mantle cell lymphoma received autologous stem-cell transplantation (ASCT) on a phase II study. Rituximab 375 mg/m(2) was administered 3 days before mobilization-dose cyclophosphamide, then weekly for four doses after count recovery from ASCT. Immune reconstitution was assessed. RESULTS: Sixty percent of transplants occurred in first remission. Actuarial event-free survival (EFS) and overall survival (OS) were 60% and 73%, respectively, at 5 years, with 7.2-year median follow-up for OS in surviving patients. Median EFS was 8.3 years. Older age and transformed lymphomas were independently associated with inferior EFS, whereas day 60 lymphocyte counts did not predict EFS or late infections. Early and late transplant-related mortality was 1% and 8%, with secondary leukemia in two patients. B-cell counts recovered by 1-2 years; however, the median IgG level remained low at 2 years. Late-onset idiopathic neutropenia, generally inconsequential, was noted in 43%. CONCLUSION: ASCT with rituximab can produce durable remissions on follow-up out to 10 years. Major infections do not appear to be significantly increased or to be predicted by immune monitoring.
Assuntos
Anticorpos Monoclonais/administração & dosagem , Sistema Imunitário/fisiologia , Linfoma de Célula do Manto , Linfoma , Recuperação de Função Fisiológica/imunologia , Transplante de Células-Tronco/métodos , Adulto , Idoso , Anticorpos Monoclonais Murinos , Antineoplásicos/administração & dosagem , Terapia Combinada , Esquema de Medicação , Feminino , Humanos , Imunoterapia , Linfoma/imunologia , Linfoma/patologia , Linfoma/reabilitação , Linfoma/terapia , Linfoma de Célula do Manto/imunologia , Linfoma de Célula do Manto/patologia , Linfoma de Célula do Manto/reabilitação , Linfoma de Célula do Manto/terapia , Masculino , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Rituximab , Imunologia de Transplantes , Transplante AutólogoRESUMO
The cancer stem cell (CSC) hypothesis suggests that clonogenic growth potential within an individual tumor is restricted to a specific and phenotypically defined cell population. Evidence for CSC in human tumors initially arose from studies of AML, but functionally similar cell populations have been identified in an increasing number of malignancies. Despite these findings, controversy surrounds the CSC hypothesis, especially the generalization that clonogenic tumor cells are rare. Nevertheless, efforts to define the cellular processes regulating self-renewal and resistance to anticancer therapeutics, two of the major properties ascribed to CSC, are likely to provide useful insights into tumor biology as a whole. BMT has been at the forefront of clinically translating basic stem cell concepts starting with the original hypothesis that normal hematopoietic precursors could rescue patients from myeloablative doses of radiation or chemotherapy. Even today, a better understanding of CSC may enhance ongoing efforts to induce specific and effective anti-tumor immune responses in both the allogeneic and autologous setting. It is also likely that new clinical research approaches will be required to accurately evaluate novel CSC-targeting strategies. Owing to the capacity to produce remissions in most diseases, SCT may provide the ideal clinical platform to carry out these investigations by studying the ability of anti-CSC agents to prolong relapse free and overall survival.
Assuntos
Células-Tronco Neoplásicas/fisiologia , Transplante de Células-Tronco , Animais , Humanos , Leucemia L1210/fisiopatologia , Camundongos , Neoplasias/tratamento farmacológico , Neoplasias/etiologia , Células-Tronco Neoplásicas/efeitos dos fármacosRESUMO
Graft failure after allogeneic blood or marrow transplantation, although generally uncommon, can be a devastating complication. This report includes the outcome of nine patients who received a salvage transplant for failure to engraft after one (n=8) or 2 (n=1) prior transplants. Eight patients received allografts from the original donor. All received fludarabine 30 mg/m(2) i.v. and alemtuzumab 20 mg i.v. daily from days -6 to -2. Daily CYA was begun on day -2, and the allograft was infused on day 0. The therapy was well tolerated with low toxicity, and all nine patients engrafted, recovering neutrophils at a median of 12 days after transplant. Four patients died: two of relapse, one of a fungal infection in the setting of GVHD and one of multiple sclerosis. The combination of fludarabine and alemtuzumab is an effective and well-tolerated salvage conditioning regimen for patients who experience graft failure after blood or marrow transplants.
Assuntos
Anticorpos Monoclonais/administração & dosagem , Anticorpos Antineoplásicos/administração & dosagem , Protocolos de Quimioterapia Combinada Antineoplásica/administração & dosagem , Transplante de Medula Óssea/métodos , Condicionamento Pré-Transplante/métodos , Vidarabina/análogos & derivados , Adulto , Alemtuzumab , Anticorpos Monoclonais Humanizados , Feminino , Rejeição de Enxerto , Humanos , Imunossupressores/uso terapêutico , Masculino , Pessoa de Meia-Idade , Recidiva , Estudos Retrospectivos , Terapia de Salvação/métodos , Resultado do Tratamento , Vidarabina/administração & dosagemRESUMO
Despite extensive study in many malignancies, maintenance therapy has clinically benefited only two diseases: acute lymphocytic leukemia (ALL) and acute promyelocytic leukemia (APL). ALL maintenance therapy utilizes low-dose 6-mercaptopurine (6MP) and methotrexate (MTX), while maintenance in APL primarily consists of all-trans-retinoic acid (ATRA). 6MP and MTX as used in ALL are also now usually added to maintenance ATRA for APL, based on data suggesting an improved disease-free survival. Although the mechanism of action of MTX and 6MP as maintenance is unknown, low-dose cytotoxic agents are potent inducers of differentiation in vitro. Thus, we studied whether maintenance therapy in ALL, like ATRA in APL, may be inducing terminal differentiation of ALL progenitors. The APL cell line NB4, the ALL cell lines REH and RS4;11, and patients' ALL blasts were incubated with ATRA, 6MP, and MTX in vitro. All three drugs inhibited the clonogenic growth of the APL and ALL cell lines without inducing immediate apoptosis, but associated with induction of phenotypic differentiation. The three drugs similarly upregulated lymphoid antigen expression, while decreasing CD34 expression, on patients' ALL blasts. These data suggest that induction of leukemia progenitor differentiation plays an important role in the mechanism of action of maintenance therapy in ALL.
Assuntos
Antimetabólitos Antineoplásicos/farmacologia , Antineoplásicos/farmacologia , Mercaptopurina/farmacologia , Metotrexato/farmacologia , Leucemia-Linfoma Linfoblástico de Células Precursoras/patologia , Tretinoína/farmacologia , Adolescente , Adulto , Diferenciação Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Células Clonais , Citotoxinas/farmacologia , Células-Tronco Hematopoéticas/citologia , Células-Tronco Hematopoéticas/efeitos dos fármacos , Humanos , Imunofenotipagem , Técnicas In Vitro , Pessoa de Meia-Idade , Leucemia-Linfoma Linfoblástico de Células Precursoras/tratamento farmacológico , Indução de RemissãoRESUMO
Aplastic anemia (AA) and hypoplastic myelodysplastic syndromes (hMDS) are often difficult to distinguish. However, an accurate diagnosis is important because the prognosis and treatment of these diseases may differ. CD34+ hematopoietic progenitors are central to the pathogenesis of both disorders; they are the targets of the autoimmune attack in AA and neoplastic transformation in MDS. The aim of this study was to assess whether bone marrow CD34+ cell numbers could be used in differentiating between AA and hMDS. The percentage of bone marrow CD34+ cells was normal or increased (mean -3.5+0.5%, range 1-7%) in 15 of 35 patients studied, and low (mean -0.13 +/- 0.02%, range 0.02-0.36%) in 20 of 35 patients. All patients with a normal or increased percentage of CD34+ cells were ultimately diagnosed with hMDS based on the detection of clonal cytogenetic abnormalities or progression to refractory anemia with excess blasts/acute myeloid leukemia. All patients with low marrow CD34+ cell numbers met standard clinical criteria for AA and have not demonstrated neoplastic transformation with follow-up. Quantification of marrow CD34+ cells may serve as an important tool for distinguishing between AA and hMDS.
Assuntos
Anemia Aplástica/imunologia , Antígenos CD34/imunologia , Células da Medula Óssea/imunologia , Síndromes Mielodisplásicas/imunologia , Adulto , Humanos , Prognóstico , Estudos RetrospectivosRESUMO
The glucocorticoid receptor (GR) displays distinct modes of regulation when bound at glucocorticoid response elements (GREs) bearing different binding sequences and arrangements of binding sites. For example, it has been shown to activate transcription synergistically with itself or with other regulatory factors, such as AP1, when bound to a consensus palindromic element or "simple GRE" that is multimerized or linked tightly with an AP1 site. In contrast, at certain "composite GREs" GR and AP1 bind to nonconsensus sequences, and GR either activates or represses depending on the subunit composition of AP1. To uncouple the contributions to regulatory behavior of binding sequences and binding element arrangements, we examined GR action at "paired elements," combinations of a simple GRE and a consensus AP1 site, separated by different distances. We found that GR synergized with either c-Jun or c-Jun-c-Fos at paired elements with GRE-AP1 site separations of >/=26 base pairs. In contrast, paired elements with separations of 14-18 base pairs mimicked the composite GRE, i.e. GR synergized with c-Jun and repressed c-Jun-c-Fos. In DNA binding studies, GR and AP1 cooccupied the paired elements. We conclude that the arrangement of binding sites within a compound response element can be a major determinant of regulatory factor action.
Assuntos
DNA/metabolismo , Receptores de Glucocorticoides/metabolismo , Ativação Transcricional , Animais , Sítios de Ligação , Bovinos , Linhagem Celular , Dexametasona/farmacologia , Eletroforese em Gel de Poliacrilamida , Glucocorticoides/farmacologia , Camundongos , Conformação de Ácido Nucleico , Proteínas Proto-Oncogênicas c-fos/metabolismo , Proteínas Proto-Oncogênicas c-jun/metabolismo , Proteínas Repressoras/metabolismo , Relação Estrutura-Atividade , Fator de Transcrição AP-1/metabolismo , Ativação Transcricional/efeitos dos fármacosRESUMO
The glucocorticoid receptor (GR) activates transcription in certain glucocorticoid response element (GRE) contexts, and represses or displays no activity in others. We isolated point mutations in one GRE, plfG, at which GR activated transcription under conditions in which the wild-type element was inactive or conferred repression, implying that GREs may carry signals that are interpreted by bound receptors. Consistent with this notion, we identified a mutant rat GR, K461A, which activated transcription in all GRE contexts tested, implying that this residue is important in interpretation of GRE signals. In a yeast screen of 60,000 GR mutants for strong activation from plfG, all 13 mutants isolated contained substitutions at K461. This lysine residue is highly conserved in the zinc-binding region (ZBR) of the intracellular receptor (IR) superfamily; when it was mutated in MR and RARbeta, the resulting receptors similarly activated transcription at response elements that their wild-type counterparts repressed or were inactive. We suggest that IR response elements serve in part as signaling components, and that a critical lysine residue serves as an allosteric "lock" that restricts IRs to inactive or repressing configurations except in response element contexts that signal their conversion to transcriptional activators. Therefore, mutation of this residue produces altered receptors that activate in many or all response element contexts.
Assuntos
Receptores de Glucocorticoides/metabolismo , Sequências Reguladoras de Ácido Nucleico , Transdução de Sinais , Animais , Sequência de Bases , Sítios de Ligação , DNA , Dados de Sequência Molecular , Mutagênese , Ratos , Receptores de Mineralocorticoides/metabolismo , Receptores do Ácido Retinoico/metabolismo , Sequências Reguladoras de Ácido Nucleico/genética , Relação Estrutura-Atividade , Ativação TranscricionalRESUMO
Eighty-one patients with metastatic liver tumors were studied by ultrasound color Doppler flow mapping examination. Primary origins consisted of gastric (19 cases), colorectal (40 cases), breast (7 cases), pancreatic (3 cases), gallbladder (3 cases) cancers and the others (9 cases). Metastatic lesions originated from breast, gastric and colorectal cancers had higher detection rates, however no blood flow could be observed within metastatic liver cancers from pancreatic and gallbladder cancers. There were no differences among the maximum blood flow velocity (Vmax), the resistance index (RI) and the pulsatile index (PI) in various metastatic liver tumors. In case of colorectal cancers, metastatic lesions originated from moderately differentiated adenocarcinoma had significantly lower RI (p < 0.05) and PI (p < 0.01) than that from well differentiated adenocarcinoma. In conclusion, ultrasound color Doppler flow mapping examination is a useful method for evaluation of the blood flow within metastatic liver tumors and could offer the histological differentiation of the primary origins, in case of metastatic liver cancers originated from colorectal cancers.
Assuntos
Circulação Hepática , Neoplasias Hepáticas/diagnóstico por imagem , Neoplasias Hepáticas/fisiopatologia , Ultrassonografia Doppler em Cores , Adulto , Idoso , Idoso de 80 Anos ou mais , Velocidade do Fluxo Sanguíneo , Neoplasias do Colo/patologia , Feminino , Hemodinâmica , Humanos , Neoplasias Hepáticas/secundário , Masculino , Pessoa de Meia-Idade , Fluxo Pulsátil , Neoplasias Retais/patologia , Neoplasias Gástricas/patologiaRESUMO
Fluorescence image analysis of isolated rat hepatocyte couplets, which retain a bile canaliculus between them, has shown the presence of transport systems for the bile acid and non-bile acid organic anion in the canalicular membrane. The cells also transported Fura-2 and BCECF, which are fluorescent indicators of intracellular Ca2+ and H+ concentrations, respectively, into the canaliculus. Both Fura-2 and BCECF transports were inhibited by progesterone, verapamil, vinblastine, and daunomycin, indicating that the transports are due to a multidrug efflux pump (P-glycoprotein) in the canalicular membrane. Interestingly, the transport by the multidrug efflux pump was inhibited by immunosuppressants FK506 (tacrolimus) and cyclosporine, their half-maximal inhibitory concentrations in the cell suspension being 10 microM and 0.6 microM, respectively. In contrast, the reported immunosuppressive potency of FK506 is 10- to 100-fold that of cyclosporine. Inhibition by immunosuppressants of the multidrug efflux pump, which is a transporter of cytotoxic and other drugs and present in normal human tissues--such as kidney, liver, the blood-brain barrier, and colon--may, at least partly, explain side effects caused by cyclosporine in these tissues of transplant recipients. FK506 at its clinical concentrations may not inhibit the multidrug efflux pump.
Assuntos
Ciclosporina/farmacologia , Fígado/citologia , Glicoproteínas de Membrana/antagonistas & inibidores , Tacrolimo/farmacologia , Membro 1 da Subfamília B de Cassetes de Ligação de ATP , Animais , Canalículos Biliares/ultraestrutura , Daunorrubicina/farmacologia , Resistência a Medicamentos , Fluoresceínas , Corantes Fluorescentes , Fura-2 , Microscopia de Fluorescência/métodos , Progesterona/farmacologia , Ratos , Processamento de Sinais Assistido por Computador , Verapamil/farmacologia , Vimblastina/farmacologiaRESUMO
AP-2 is the class of clathrin-associated protein complex found in coated vesicles derived from the plasma membrane of eukaryotic cells. We demonstrate here, using a chemical method, that an AP-2 complex is an asymmetric structure consisting of one large alpha chain, one large beta chain, one medium AP50 chain, and one small AP17 chain. The complex has been shown to contain a core and two appendages. The AP core includes the small AP17 and the medium AP50 chains together with the amino-terminal domains of the large alpha and beta chains. One appendage corresponds to the carboxy-terminal domain of the beta chain. We find that as in the case of the beta chains, the carboxy-terminal portion of the alpha chains is an independently folded domain corresponding to the second appendage. We use limited tryptic proteolysis of clathrin/AP-2 coats to show the release of the appendages from the interior of the coats and the retention of the AP core by the remaining clathrin lattice. In addition, we find that the AP core stabilizes the coat and prevents its depolymerization. These results are consistent with the proposal that the AP core contains the binding site(s) for clathrin, while the alpha- and beta-chain appendages interact with membrane components of coated pits and coated vesicles.
Assuntos
Complexo 2 de Proteínas Adaptadoras , Subunidades mu do Complexo de Proteínas Adaptadoras , Subunidades sigma do Complexo de Proteínas Adaptadoras , Clatrina/metabolismo , Invaginações Revestidas da Membrana Celular/química , Fosfoproteínas/química , Proteínas Adaptadoras de Transporte Vesicular , Sequência de Aminoácidos , Aminoácidos/análise , Animais , Sítios de Ligação , Encéfalo/ultraestrutura , Bovinos , Invaginações Revestidas da Membrana Celular/metabolismo , Invaginações Revestidas da Membrana Celular/ultraestrutura , Substâncias Macromoleculares , Microscopia Eletrônica , Dados de Sequência Molecular , Fragmentos de Peptídeos/metabolismo , Fosfoproteínas/metabolismo , Homologia de Sequência do Ácido Nucleico , Soluções , TripsinaRESUMO
The clathrin-associated protein complex 2 (AP-2 complex) is a group of proteins associated with clathrin-coated vesicles and believed to interact with cytoplasmic domains of receptors found in the plasma membrane. AP-2 was purified as an assembly of several polypeptide chains (alpha, beta, AP50, and AP17), of which only the alpha and beta chains (100-115 kDa) show significant heterogeneity. We have obtained cDNA clones for two distinct rat brain beta chains. We have also studied the domain organization of bovine brain AP-2 complexes by selective proteolysis. Results of these studies show that the alpha and beta chains have a similar two-domain organization. Their amino-terminal domains are relatively invariant whereas their carboxyl-terminal domains are variable in both sequence and length. We propose that the variable domains select receptors for inclusion in coated vesicles.
Assuntos
Complexo 2 de Proteínas Adaptadoras , Subunidades mu do Complexo de Proteínas Adaptadoras , Subunidades sigma do Complexo de Proteínas Adaptadoras , Clatrina , Fosfoproteínas/genética , Proteínas Adaptadoras de Transporte Vesicular , Sequência de Aminoácidos , Animais , Sequência de Bases , Bovinos , Clonagem Molecular , Invaginações Revestidas da Membrana Celular/análise , DNA/genética , Substâncias Macromoleculares , Dados de Sequência Molecular , Peso Molecular , Fragmentos de Peptídeos/análise , RatosRESUMO
Diagnosis of thyroid cancer has been based mainly on palpation and also soft X-rays because of its calcification. As the gland itself is very small and Aspiration Biopsy Cytology (ABC) has had a high level of diagnostic accuracy the clinical significance of ultrasonography did not become apparent for a long time. However, recently it has become possible to carry out detailed study and to detect suspect histological structures, following the remarkable progress which has been made in ultrasonography, using a high-frequency piezoelectric transducer. A single mechanical arch scanner, with a piezoelectric 7.5-MHz transducer (SAL-25A Toshiba Corp.) was employed for examination using the water bath method. The rates of correct diagnosis for each of the above methods among 847 nodular goiters including 184 malignant tumors which were microscopically examined were shown to be: ultrasonography 89.7%, soft X-rays 66.9% and ABC 86.4%. Ultrasonography was capable to revealing a few cases which could not be shown by ABC or soft X-rays. Using these three methods jointly, there was 1 false positive and no false negative cases. This study revealed that combined diagnosis with ultrasonography using a high-frequency piezoelectric transducer improved the accuracy of examination of malignant thyroid tumors.