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2.
Transplant Proc ; 47(3): 799-803, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25724252

RESUMO

The patient was a 45-year-old man with underlying alcoholic liver cirrhosis. Two years prior, he was repeatedly hospitalized for liver failure symptoms and requested a living-donor liver transplantation (LDLT) because of end-stage cirrhosis. A pretransplantation blood test revealed a high 1,3-beta-d-glucan (BDG) value of 102.0 pg/mL (reference value <20.0 pg/mL) and a high blood Aspergillus antigen (AsAg) value of 1.6 cutoff index (COI; reference value <0.5 COI). Contrast-enhanced thoracoabdominal-pelvic computed tomography (CT) and cranial magnetic resonance imaging revealed no fungal infection. However, latent fungal infection could not be ruled out, hence preoperative antifungal agent treatment was administered. BDG and AsAg levels showed a decreasing trend after treatment initiation. However, normalization did not occur; the BDG and AsAg levels were 25.8 pg/mL and 1.0 COI, respectively. Although the possibility of latent fungal infection was judged low, we prophylactically administered antifungal agents after LDLT. The BDG level consistently increased at 35-39 pg/mL until postoperative day 5 but subsequently normalized. The AsAg level was higher than the limit of detection at 5.0 COI on postoperative day 3 but normalized to 0.2 COI on postoperative day 5 and did not subsequently increase. The postoperative course was uneventful despite bacterial pneumonia and the patient was discharged on postoperative day 35. A histopathologic examination (Grocott methenamine silver staining) and a fungal polymerase chain reaction assay were performed for the resected liver, but the results of both were negative. At 9 postoperative months, the patient was making ambulatory follow-up visits. Currently, the BDG and AsAg values remain normal and clinical progress is favorable. We found no reports of LDLT for a recipient with a high preoperative BDG level and positive test result for AsAg. Thus, we report on such a case with a discussion of the literature on the causes of high preoperative BDG and AsAg values.


Assuntos
Antifúngicos/uso terapêutico , Antígenos de Fungos/sangue , Aspergilose/prevenção & controle , Aspergillus/imunologia , Transplante de Fígado , Complicações Pós-Operatórias/prevenção & controle , beta-Glucanas/sangue , Aspergilose/diagnóstico , Biomarcadores/sangue , Humanos , Doadores Vivos , Masculino , Pessoa de Meia-Idade , Cuidados Pós-Operatórios , Complicações Pós-Operatórias/diagnóstico , Cuidados Pré-Operatórios , Proteoglicanas
3.
Histopathology ; 44(2): 164-71, 2004 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-14764060

RESUMO

AIMS: Polymorphous low-grade adenocarcinoma (PLGA) is the second most common type of malignant neoplasm in minor salivary glands. Its origin in major salivary glands is considered exceedingly rare. Herein, we present three cases of de novo PLGA arising in major salivary glands. METHODS AND RESULTS: Three cases of PLGA were identified in a large series of primary tumours of major salivary glands. We investigated their clinicopathological profiles, including immunohistochemical features. The three patients (two men and one woman) were 51, 65, and 79 years old. The tumours were 20-30 mm large; two were in the parotid gland and one in the submandibular gland. Histologically, all the tumours had a polymorphous architectural pattern showing predominantly solid, tubular, and cribriform features and invasive growth. Papillary areas were observed focally in two tumours and an 'Indian-file' array in one. The tumour cells had a bland cytological appearance and low mitotic count. Two tumours showed perineural invasion. No preexisting pleomorphic adenoma component was identified. In all cases, tumour cells were positive for epithelial markers, S100 protein, and vimentin but negative for alpha-smooth muscle actin, muscle-specific actin, and glial fibrillary acidic protein. Proliferative activities assessed with the Ki67 labelling index were 4.3%, 7.1%, and 7.6%; no p53 overexpression was observed. Two patients had local recurrence, but none had metastasis or died of tumour. CONCLUSIONS: PLGAs arising in major salivary glands and those in minor salivary glands have similar clinicopathological and immunohistochemical characteristics. It is important to recognize that PLGA can occur ab initio in the major salivary glands, although it is extremely rare.


Assuntos
Adenocarcinoma/patologia , Neoplasias Parotídeas/patologia , Neoplasias da Glândula Submandibular/patologia , Adenocarcinoma/metabolismo , Idoso , Feminino , Humanos , Imuno-Histoquímica , Masculino , Pessoa de Meia-Idade , Neoplasias Parotídeas/metabolismo , Estudos Retrospectivos , Neoplasias da Glândula Submandibular/metabolismo
7.
Int J Hematol ; 74(2): 193-6, 2001 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-11594521

RESUMO

We report 2 patients with follicular lymphoma (FL) which was accompanied by Waldenström's macroglobulinemia (WM). One patient was a 65-year-old woman and the other a 60-year-old man. Both patients showed a high level of circulating macroglobulin (4.6 g/dL and 3.6 g/dL, respectively) and bone marrow involvement of small lymphoid cells. Moreover, in each case, the macroglobulin-producing component and the follicular component were determined to be of the same clone based on their identical light-chain restriction pattern and other factors. However, there was a difference in the histopathological characteristics of the macroglobulin-producing components of the 2 patients, especially the cytoplasmic immunoglobulin (Ig)M+ cell distribution in the biopsied lymph nodes. Test results for the female patient showed intrafollicular proliferation of those cells. The male patient's test results showed that IgM+ cells were located in the narrow extrafollicular areas of the lymph nodes. Our observations suggest that at least 2 different subtypes of FL may also be causative of a WM presentation.


Assuntos
Linfoma Folicular/complicações , Linfoma Folicular/metabolismo , Macroglobulinas/metabolismo , Macroglobulinemia de Waldenstrom/etiologia , Macroglobulinemia de Waldenstrom/metabolismo , Idoso , Medula Óssea/química , Medula Óssea/patologia , Feminino , Humanos , Imuno-Histoquímica , Linfonodos/química , Linfonodos/patologia , Masculino , Pessoa de Meia-Idade
8.
Rinsho Ketsueki ; 42(5): 420-5, 2001 May.
Artigo em Japonês | MEDLINE | ID: mdl-11452463

RESUMO

A 65-year-old man was admitted with swelling of the right neck and bilateral inguinal lymph nodes. Endoscopic examination revealed no nasal infiltration. Pathological examination of a neck lymph node biopsy specimen revealed peripheral T-cell lymphoma according to the Revised European-American Classification of Lymphoid Neoplasms (REAL). The phenotype of the lymphoma cells was CD56+, CD16-, CD2+, surface CD3-, cytoplasmic CD3+, CD4+, CD8-, CD5+, CD7- and CD45RO+. May-Giemsa staining demonstrated no azurophilic granules in the lymphoma cells. Immunohistopathologic examination showed negativity for TIA-1 and granzyme B, and rearrangement of the TCR C beta 1 gene was also noted. These findings strongly suggested that this was a T-cell lymphoma. The patient received 8 courses of CHOP chemotherapy plus sobuzoxane. This led to a marked decrease of lymph node swelling, and currently the patient is still in remission. According to the REAL classification, T/NK-cell lymphomas are included among the peripheral T cell tumours, and seem to constitute a heterogeneous group of neoplasms. Although some cases of CD4+ CD56+ lymphoma have been reported, the present case appears to be the first example to show TCR gene rearrangement and negativity for TIA-1 and granzyme B. Since the classification of T/NK-cell lymphoma is still controversial, accumulation of such cases may help to better define T/NK-cell neoplasms.


Assuntos
Antígenos CD4/imunologia , Antígeno CD56/imunologia , Linfoma de Células T/imunologia , Idoso , Protocolos de Quimioterapia Combinada Antineoplásica/administração & dosagem , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Ciclofosfamida/administração & dosagem , Doxorrubicina/administração & dosagem , Esquema de Medicação , Humanos , Linfoma de Células T/tratamento farmacológico , Linfoma de Células T/patologia , Masculino , Piperazinas/administração & dosagem , Prednisolona/administração & dosagem , Indução de Remissão , Vincristina/administração & dosagem
9.
Am J Hematol ; 66(1): 49-52, 2001 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-11426493

RESUMO

We report a patient with anaplastic large-cell lymphoma (ALCL) who has been given immunosuppressive therapy for Evans syndrome for 10 years. He was admitted with spike fever, intra-abdominal lymphadenopathy, and multiple liver masses. Examination of biopsy specimens obtained by para-aortic lymph nodes and liver masses resulted in a diagnosis of ALCL. Immunohistochemically, these cells were reactive to anti-CD30 antibody but were not of B- or T-lineage. Bone marrow aspiration demonstrated the invasion of giant neoplastic cells and trilineage myelodysplasia. Because the patient showed severe inflammatory symptoms, we examined serum levels of various cytokines. Pretreatment levels of IL-6 and VEGF in this patient were significantly elevated compared to those of normal controls. He was treated with combination chemotherapy (ABVD regimen), achieving complete remission. Myelodysplasia and serum IL-6 and VEGF also normalized after treatment. We assumed that ALCL resulted from long-term immunosuppressive therapy and that the up-regulation of IL-6 and VEGF played a role in pathogenesis of this type of lymphoma.


Assuntos
Doenças Autoimunes/tratamento farmacológico , Ciclosporina/efeitos adversos , Fatores de Crescimento Endotelial/sangue , Imunossupressores/efeitos adversos , Interleucina-6/sangue , Linfocinas/sangue , Linfoma Difuso de Grandes Células B/tratamento farmacológico , Síndromes Mielodisplásicas/etiologia , Pancitopenia/tratamento farmacológico , Prednisolona/efeitos adversos , Dor Abdominal/etiologia , Protocolos de Quimioterapia Combinada Antineoplásica/administração & dosagem , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Doenças Autoimunes/complicações , Bleomicina/administração & dosagem , Medula Óssea/patologia , Relação CD4-CD8 , Linhagem da Célula , Terapia Combinada , Ciclosporina/uso terapêutico , DNA de Neoplasias/análise , DNA Viral/análise , Dacarbazina/administração & dosagem , Doxorrubicina/administração & dosagem , Febre/etiologia , Fator 2 de Crescimento de Fibroblastos/sangue , Rearranjo Gênico do Linfócito B , Humanos , Hospedeiro Imunocomprometido , Imunossupressores/uso terapêutico , Inflamação , Linfonodos/patologia , Linfoma Difuso de Grandes Células B/sangue , Linfoma Difuso de Grandes Células B/complicações , Linfoma Difuso de Grandes Células B/patologia , Masculino , Pessoa de Meia-Idade , Pancitopenia/complicações , Prednisolona/uso terapêutico , Indução de Remissão , Esplenectomia , Síndrome , Fator A de Crescimento do Endotélio Vascular , Fatores de Crescimento do Endotélio Vascular , Vimblastina/administração & dosagem
10.
Acta Cytol ; 45(3): 372-80, 2001.
Artigo em Inglês | MEDLINE | ID: mdl-11393069

RESUMO

OBJECTIVE: To ascertain the cytologic characteristics of solitary fibrous tumors of the pleura (SFTPs) on smear preparations. STUDY DESIGN: Fine needle aspiration cytology (FNAC) was initially attempted preoperatively in five cases, but the specimens were inappropriate for interpretation because only a few tumor cells were obtained. Therefore, scratch smears made at the time of operation were used. Papanicolaou and immunocytochemical staining was performed in all 10 cases, 2 of which were malignant. RESULTS: As expected, cellular tumors yielded more cells. The cytologic appearance was variable, showing spindle/bipolar, dendritic/stellate and intermediate cells. Atypical cells reminiscent of sarcoma were also present in cellular, benign tumors. Highly atypical epithelioid cells were obtained in two malignant cases. Immunocytochemically, the tumor cells were positive for CD34 and vimentin and negative for cytokeratin, regardless of histologic differences and cell shape. CONCLUSION: It seems difficult to diagnose SFTPs with certainty by FNAC, partly because the cell morphology of SFTPs resembles a wide variety of heterogeneous groups of spindle cell tumors and partly because only a few tumor cells were available in the FNAC specimens in the present study. However, a cytologic diagnosis of SFTP is possible if cytologic preparations yield CD34-positive cells with spindle/bipolar or dendritic/stellate morphology.


Assuntos
Neoplasias de Tecido Fibroso/patologia , Neoplasias Pleurais/patologia , Adulto , Idoso , Antígenos CD34/análise , Antígenos CD34/imunologia , Núcleo Celular/ultraestrutura , Tamanho Celular , Citodiagnóstico , Feminino , Humanos , Imuno-Histoquímica , Masculino , Pessoa de Meia-Idade , Neoplasias de Tecido Fibroso/química , Neoplasias de Tecido Fibroso/diagnóstico , Neoplasias Pleurais/química , Neoplasias Pleurais/diagnóstico
11.
Acta Cytol ; 45(3): 430-4, 2001.
Artigo em Inglês | MEDLINE | ID: mdl-11393080

RESUMO

BACKGROUND: Intracytoplasmic lumina have been recently recognized as a characteristic histologic feature of ependymoma. However, the cytologic diagnostic usefulness has not been discussed. We encountered two imprint cytology cases of spinal cord ependymomas in which there were intracytoplasmic lumina in the tumor cells. CASES: Two women had spinal cord tumors on magnetic resonance imaging. Imprint cytology study was carried out on the resected tumors. The cytologic specimen of the first case, aged 52, showed tumor clusters consisting of elongated epithelioid cells, a few of which also had intracytoplasmic lumina. Histologically, tumor cells formed ependymal rosettes and pseudoperivascular rosettes. There were a few tumor cells with intracytoplasmic lumina. The cytologic specimen of the second patient, aged 37, had scattered and isolated tumor cells with intracytoplasmic lumina resembling signet-ring cells and paired tumor cells forming small, glandlike structures. Histologically, the tumor was composed mainly of signet-ring-like cells containing intracytoplasmic lumina. CONCLUSION: Intracytoplasmic lumina were observed in the imprint cytologic specimens of spinal cord ependymoma. The diagnosis of ependymomas can be made cytologically when intracytoplasmic lumina are found since no other primary neuroepithelial tumors of the central nervous system possess such a characteristic feature.


Assuntos
Ependimoma/ultraestrutura , Neoplasias da Medula Espinal/ultraestrutura , Adulto , Citodiagnóstico , Ependimoma/patologia , Humanos , Pessoa de Meia-Idade , Neoplasias da Medula Espinal/patologia
13.
Leuk Lymphoma ; 41(3-4): 461-3, 2001 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-11378564

RESUMO

A case of marginal zone B cell lymphoma of MALT type arising in the uvula and breast is reported. The patient, a 30-year-old woman who delivered a child and lactated in 1997, was suffering from Sjögren syndrome (SS). She was diagnosed with MALT lymphoma after a biopsy of the right breast and uvula. To investigate the relationship of the delivery, lactation and MALT lymphoma, we examined the immunohistochemical analysis of hormone receptors. As a result, lymphoid cells of the breast were stained with anti-progesterone receptor antibodies in the cytoplasm. Consequently, the MALT lymphoma of the uvula appeared to be associated with SS. Moreover, hormones such as progesterone may have influenced the breast involvement of MALT lymphoma in our case.


Assuntos
Neoplasias da Mama/etiologia , Linfoma de Zona Marginal Tipo Células B/etiologia , Neoplasias Bucais/etiologia , Úvula , Adulto , Neoplasias da Mama/química , Neoplasias da Mama/patologia , Feminino , Humanos , Imuno-Histoquímica , Trabalho de Parto/metabolismo , Lactação/metabolismo , Linfoma de Zona Marginal Tipo Células B/química , Linfoma de Zona Marginal Tipo Células B/patologia , Gravidez , Receptores de Progesterona/metabolismo , Síndrome de Sjogren/complicações
14.
Chest ; 119(3): 981-3, 2001 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-11243992

RESUMO

We report a patient with diffuse malignant pleural mesothelioma showing marked elevation of neutrophils. The level of serum granulocyte-colony stimulating factor (G-CSF) was elevated (138 pg/mL; normal range, < 20 pg/mL). The patient died 6 weeks after disease progression had been noted, and immunohistochemistry using a specific monoclonal antibody against recombinant G-CSF at autopsy demonstrated that the malignant mesothelioma cells actually produced G-CSF. Only three cases of malignant pleural mesothelioma, including the current patient, have been reported to produce G-CSF. We demonstrated an elevated serum level of G-CSF and G-CSF-bearing tumor cells by immunochemistry.


Assuntos
Fator Estimulador de Colônias de Granulócitos/biossíntese , Mesotelioma/metabolismo , Neoplasias Pleurais/metabolismo , Fator Estimulador de Colônias de Granulócitos/sangue , Humanos , Técnicas Imunoenzimáticas , Masculino , Pessoa de Meia-Idade
15.
Digestion ; 63 Suppl 1: 97-102, 2001.
Artigo em Inglês | MEDLINE | ID: mdl-11173918

RESUMO

BACKGROUND/AIMS: Cytokine-induced neutrophil chemoattractant (CINC/gro), a member of interleukin-8 family, was found as a potent chemotactic factor for rat neutrophils. Although several chemokines have been shown to be potent regulators of T cell chemotaxis in vitro, the potential role of chemokines in T-cell migration in gut-associated lymphoid tissues has not been investigated in vivo. In the present study, the effects of CINC/gro on T-lymphocyte migration were examined in rat Peyer's patches. METHODS: T lymphocytes collected from intestinal lymph of rats were fluorescence-labeled and injected into the jugular vein. Peyer's patches of the recipient rats were observed with intravital fluorescence microscopy and the effects of CINC/gro infusion was investigated. Lymphocyte flux in mesenteric collecting lymphatics was also observed. RESULTS: In vivo infusion of CINC/gro significantly attenuated the initial lymphocyte interaction with postcapillary venules of Peyer's patches. However, once these lymphocytes adhered to venules, CINC/gro treatment significantly accelerated the transendothelial migration of T lymphocytes and they also significantly increased their subsequent flux in collecting lymphatics. CONCLUSION: There is a possibility that CINC/gro could modulate the characteristics of T lymphocyte homing in the inflammatory sites of gut.


Assuntos
Movimento Celular , Quimiocinas CXC , Fatores Quimiotáticos/farmacologia , Quimiotaxia , Inibidores do Crescimento/farmacologia , Substâncias de Crescimento/farmacologia , Peptídeos e Proteínas de Sinalização Intercelular , Intestino Delgado/imunologia , Nódulos Linfáticos Agregados/imunologia , Linfócitos T/fisiologia , Animais , Adesão Celular , Quimiocina CXCL1 , Inflamação , Intestino Delgado/patologia , Sistema Linfático , Masculino , Ratos , Ratos Wistar
16.
Eur Radiol ; 11(1): 73-5, 2001.
Artigo em Inglês | MEDLINE | ID: mdl-11194921

RESUMO

Mediastinal hemangiomas are rare tumors. We present a case of venous hemangioma of the mediastinum. Computed tomography shows anterior mediastinal solid mass without enhancement effects. We believe that it is necessary to include a mediastinal hemangioma for differential diagnosis, when little or no enhancement effects are noted at early and delayed CT examination.


Assuntos
Hemangioma/diagnóstico , Imageamento por Ressonância Magnética , Neoplasias do Mediastino/diagnóstico , Tomografia Computadorizada por Raios X , Adulto , Diagnóstico Diferencial , Feminino , Hemangioma/cirurgia , Humanos , Neoplasias do Mediastino/cirurgia , Cirurgia Torácica Vídeoassistida
17.
J Dermatol ; 28(12): 753-8, 2001 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-11804074

RESUMO

A 20-year-old woman complained of a subcutaneous nodule accompanied by spontaneous pain and tenderness in the right hypochondriac region approximately two weeks prior to initial evaluation. The spontaneous pain and tenderness gradually worsened. Histopathological examination revealed a proliferative lesion that extended from the deep dermis to the fatty tissue and consisted predominantly of stellate or spindle-shaped fibroblast-like cells intermingled with gangliocyte-like giant cells. Consequently, proliferative fasciitis was diagnosed. Our investigation revealed only 19 cases of proliferative fasciitis reported in Japan. The overall age range of them is 20 to 75 years (mean, 57.6 years). The lesion site in them is the head and neck in 10%, the trunk in 30%, and the extremities in 60%. It follows that the extremities are predominantly the site of proliferative fasciitis, and truncal lesions are relatively rare. It is rare for proliferative fasciitis to occur at a young age or in the abdominal region. We therefore examined the differences between proliferative fasciitis and similar disorders, namely proliferative myositis and nodular fasciitis, based on summaries of cases reported in Japan.


Assuntos
Fasciite/diagnóstico , Abdome , Adulto , Diagnóstico Diferencial , Fasciite/patologia , Fasciite/cirurgia , Feminino , Humanos , Imuno-Histoquímica
18.
Pathol Int ; 51(12): 954-60, 2001 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-11844069

RESUMO

Most renal cell carcinomas (RCC) are composed of clear cells with sinusoid-like vasculatures and originate from the proximal tubule. On the other hand, collecting duct carcinoma (CDC) and chromophobe RCC are thought to originate from the lower nephron. In the present study, we present a case of unusual RCC. The patient was a 68-year-old Japanese woman who had developed general fatigue with hematuria. Computed tomography revealed a left renal tumor suggesting sarcoma. The resected tumor was located in the renal parenchyma, measuring 12 x 10 x 8 cm in size. Histologically, the tumor consisted principally of cuboidal cells forming parallel or radiating arrays, continuous with the spindle-shaped cells. Most parts of the tumor showed hemorrhagic necrosis. Immunohistochemically, tumor cells were positive for high molecular weight cytokeratins, vinculin, vimentin, CD15 and epithelial membrane antigen, and showed affinities with some kinds of lectins. N- and E-cadherins and beta-catenin were diffusely positive in tumor cells. Nuclear positivity for Ki-67 and p53 protein were approximately 2.0 and 1.7%, respectively. Considering its morphological and histochemical natures, this tumor is considered to have originated from the lower nephron, which is unique for a tumor of low-grade malignancy.


Assuntos
Carcinoma de Células Renais/ultraestrutura , Neoplasias Renais/ultraestrutura , Néfrons/ultraestrutura , Idoso , Biomarcadores Tumorais/análise , Caderinas/análise , Carcinoma de Células Renais/química , Carcinoma de Células Renais/cirurgia , Feminino , Humanos , Técnicas Imunoenzimáticas , Neoplasias Renais/química , Neoplasias Renais/cirurgia , Lectinas/análise , Microscopia Eletrônica , Mucina-1/análise , Néfrons/química , Organelas/ultraestrutura , Tomografia Computadorizada por Raios X , Vimentina/análise , Vinculina/análise
19.
J Clin Gastroenterol ; 31(3): 258-61, 2000 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-11034012

RESUMO

Both hemangioma and inflammatory pseudotumor (IPT) of the spleen are rare benign mass lesions. Moreover, a splenic hemangioma accompanied by IPT is extremely rare. A 61-year-old woman who suffered from liver cirrhosis had a splenic cavernous hemangioma surrounded by granuloma. The literature on IPT of the spleen has described several possibilities of its causes; however, it is still unknown. This case was accompanied by portal hypertension due to liver cirrhosis, which may cause microrupture of hemangioma resulting in an IPT.


Assuntos
Granuloma de Células Plasmáticas/complicações , Hemangioma Cavernoso/complicações , Esplenopatias/complicações , Neoplasias Esplênicas/complicações , Feminino , Humanos , Hipertensão Portal/etiologia , Cirrose Hepática/complicações , Pessoa de Meia-Idade
20.
Mol Cell Biol ; 20(20): 7726-34, 2000 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-11003668

RESUMO

The eukaryotic cell cycle is regulated by cyclin-dependent kinases (CDKs). CDK4 and CDK6, which are activated by D-type cyclins during the G(1) phase of the cell cycle, are thought to be responsible for phosphorylation of the retinoblastoma gene product (pRb). The tumor suppressor p16(INK4A) inhibits phosphorylation of pRb by CDK4 and CDK6 and can thereby block cell cycle progression at the G(1)/S boundary. Phosphorylation of the carboxyl-terminal domain (CTD) of the large subunit of RNA polymerase II by general transcription factor TFIIH is believed to be an important regulatory event in transcription. TFIIH contains a CDK7 kinase subunit and phosphorylates the CTD. We have previously shown that p16(INK4A) inhibits phosphorylation of the CTD by TFIIH. Here we report that the ability of p16(INK4A) to inhibit CDK7-CTD kinase contributes to the capacity to induce cell cycle arrest. These results suggest that p16(INK4A) may regulate cell cycle progression by inhibiting not only CDK4-pRb kinase activity but also by modulating CDK7-CTD kinase activity. Regulation of CDK7-CTD kinase activity by p16(INK4A) thus may represent an alternative pathway for controlling cell cycle progression.


Assuntos
Proteínas de Transporte/metabolismo , Proteínas de Ciclo Celular , Ciclo Celular , Proteínas Quinases/metabolismo , Proteínas Serina-Treonina Quinases/metabolismo , Proteínas Proto-Oncogênicas , Fatores de Transcrição TFII , Proteínas Supressoras de Tumor , Sequência de Aminoácidos , Substituição de Aminoácidos , Proteínas de Transporte/química , Proteínas de Transporte/genética , Ciclina H , Quinase 4 Dependente de Ciclina , Inibidor de Quinase Dependente de Ciclina p15 , Inibidor p16 de Quinase Dependente de Ciclina , Quinases Ciclina-Dependentes/antagonistas & inibidores , Quinases Ciclina-Dependentes/metabolismo , Ciclinas/antagonistas & inibidores , Ciclinas/metabolismo , Citometria de Fluxo , Células HeLa , Humanos , Substâncias Macromoleculares , Microscopia de Fluorescência , Dados de Sequência Molecular , Mutação , Fenótipo , Fosforilação , Inibidores de Proteínas Quinases , Proteínas Quinases/genética , Proteínas Serina-Treonina Quinases/antagonistas & inibidores , Proteínas Serina-Treonina Quinases/genética , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/metabolismo , Proteína do Retinoblastoma/metabolismo , Alinhamento de Sequência , Fator de Transcrição TFIIH , Fatores de Transcrição/antagonistas & inibidores , Fatores de Transcrição/química , Fatores de Transcrição/metabolismo , Quinase Ativadora de Quinase Dependente de Ciclina
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