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1.
Oncologist ; 26(3): e500-e504, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-33210439

RESUMO

The SARS-CoV-2 (COVID-19) pandemic continues to affect many lives globally. Patients with cancer undergoing potentially immunosuppressive therapies appear to be at particular risk for the disease and its complications. Here, we describe the experience of patients with cancer within Kaiser Permanente, a large, integrated health system in Northern California. Between February 25, 2020, and June 8, 2020, 4,627 patients were diagnosed with COVID-19, of whom 33 had active cancer treatment within 180 days and 214 had a history of cancer. Patients with active cancer treatment had a statistically higher risk of requiring noninvasive ventilation (odds ratio [OR], 2.57; confidence interval [CI], 1.10-6.01), and there was a nonsignificant trend toward higher risk of death (OR, 2.78; CI, 0.92-8.43). Those with a history of cancer had comparable outcomes to those without cancer. These data demonstrate an increased risk of complications from COVID-19 for patients with active cancer treatment.


Assuntos
COVID-19/complicações , Neoplasias/complicações , Neoplasias/imunologia , Avaliação de Resultados em Cuidados de Saúde , Pneumonia Viral/complicações , Adolescente , Adulto , Idoso , COVID-19/epidemiologia , California/epidemiologia , Feminino , Humanos , Hospedeiro Imunocomprometido , Masculino , Pessoa de Meia-Idade , Pandemias , Pneumonia Viral/virologia , Estudos Retrospectivos , SARS-CoV-2
2.
Anticancer Res ; 40(7): 4029-4032, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32620648

RESUMO

The synchronous diagnosis of two or more primary malignancies in a patient is overall rare. This is a case report of a 70-year-old female with a history of skin squamous cell carcinoma presenting with occult hematochezia. Colonoscopy and biopsy results confirmed a microsatellite stable (MMS) adenocarcinoma in the ascending colon, and subsequent computed tomography (CT) scans identified a 3.2 cm right colonic mass and a 5.0 cm mass in the pancreatic body. Endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) confirmed the presence of pancreatic ductal adenocarcinoma (PDAC). The patient underwent neo-adjuvant FOLFIRINOX (folinic acid, fluorouracil, irinotecan and oxaliplatin) chemotherapy prior to the simultaneous distal pancreatectomy and right hemicolectomy for both pancreatic and colonic tumors. The pathology diagnoses included moderately differentiated pancreatic ductal carcinoma (PDAC) with histiocyte-like features (tumor stage: ypT3N1M0) and moderately differentiated colonic adenocarcinoma, intestinal type (tumor stage: ypT3N0M0). To the best of our knowledge, this is the first documented case of synchronous primary colonic adenocarcinoma and PDAC in the English literature.


Assuntos
Adenocarcinoma/diagnóstico , Carcinoma Ductal Pancreático/diagnóstico , Neoplasias do Colo/diagnóstico , Neoplasias Primárias Múltiplas/diagnóstico , Neoplasias Pancreáticas/diagnóstico , Adenocarcinoma/patologia , Idoso , Antineoplásicos/uso terapêutico , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Carcinoma Ductal Pancreático/patologia , Carcinoma de Células Escamosas , Neoplasias do Colo/patologia , Feminino , Fluoruracila/uso terapêutico , Humanos , Irinotecano/uso terapêutico , Leucovorina/uso terapêutico , Neoplasias Primárias Múltiplas/patologia , Oxaliplatina/uso terapêutico , Neoplasias Pancreáticas/patologia , Neoplasias Cutâneas
3.
J Urol ; 202(4): 732-741, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31216253

RESUMO

PURPOSE: Approximately 15% of men with newly diagnosed prostate cancer have high risk features which increase the risk of recurrence and metastasis. Better predictive biomarkers could allow for earlier detection of biochemical recurrence and change surveillance and adjuvant treatment paradigms. Circulating tumor cells are thought to represent the earliest form of metastases. However, their role as biomarkers in men with high risk, localized prostate cancer is not well defined. MATERIALS AND METHODS: Two to 5 months after prostatectomy we obtained blood samples from 37 patients with high risk, localized prostate cancer, defined as stage T3a or higher, Gleason score 8 or greater, or prostate specific antigen 20 ng/ml or greater. Circulating tumor cells were enumerated using a commercial platform. Matched tumor and single circulating tumor cell sequencing was performed. RESULTS: Circulating tumor cells were detected in 30 of 37 samples (81.1%) with a median of 2.4 circulating tumor cells per ml (range 0 to 22.9). Patients with detectable circulating tumor cells showed a trend toward shorter recurrence time (p=0.12). All patients with biochemical recurrence had detectable circulating tumor cells. Androgen receptor over expression was detected in 7 of 37 patients (18.9%). Patients with biochemical recurrence had more circulating tumor cell copy number aberrations (p=0.027). Matched tumor tissue and single circulating tumor cell sequencing revealed heterogeneity. CONCLUSIONS: We noted a high incidence of circulating tumor cell detection after radical prostatectomy and shorter time to biochemical recurrence in men with a higher circulating tumor cell burden and more circulating tumor cell copy number aberrations. Genomic alterations consistent with established copy number aberrations in prostate cancer were detectable in circulating tumor cells but often discordant with cells analyzed in bulk from primary lesions. With further testing in appropriately powered cohorts early circulating tumor cell detection could be an informative biomarker to assist with adjuvant treatment decisions.


Assuntos
Recidiva Local de Neoplasia/patologia , Células Neoplásicas Circulantes/metabolismo , Prostatectomia , Neoplasias da Próstata/patologia , Idoso , Biomarcadores Tumorais/sangue , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Recidiva Local de Neoplasia/diagnóstico , Estadiamento de Neoplasias , Prognóstico , Neoplasias da Próstata/diagnóstico , Neoplasias da Próstata/cirurgia , Receptores Androgênicos , Risco
4.
Clin Genitourin Cancer ; 15(6): 733-741.e1, 2017 12.
Artigo em Inglês | MEDLINE | ID: mdl-28655452

RESUMO

BACKGROUND: Abiraterone acetate (AA) inhibits androgen biosynthesis and prolongs survival in men with metastatic castration-resistant prostate cancer (mCRPC) when combined with prednisone (P). Resistance to therapy remains incompletely understood. In this open-label, single-arm, multicenter phase II study we investigated the clinical benefit of increasing the dose of AA at the time of resistance to standard-dose therapy. PATIENTS AND METHODS: Eligible patients had progressive mCRPC and started AA 1000 mg daily and P 5 mg twice daily. Patients who achieved any prostate-specific antigen (PSA) decline after 12 weeks of therapy continued AA with P until PSA or radiographic progression. At progression, AA was increased to 1000 mg twice daily with unchanged P dosing. Patients were monitored for response to therapy for a minimum of 12 weeks or until PSA or radiographic progression. The primary end point was PSA decline of at least 30% after 12 weeks of therapy at the increased dose of AA. RESULTS: Forty-one patients were enrolled from March 2013 through March 2014. Thirteen men experienced disease progression during standard-dose therapy and were subsequently treated with AA 1000 mg twice per day. Therapy was well tolerated. No PSA declines ≥ 30% nor radiographic responses were observed after 12 weeks of dose-escalated therapy. Higher baseline dehydroepiandrosterone levels, lower circulating tumor cell burden, and higher pharmacokinetic levels of abiraterone and abiraterone metabolites were associated with response to standard-dose therapy. CONCLUSION: Increasing the dose of abiraterone at the time of resistance has limited clinical utility and cannot be recommended. Lower baseline circulating androgen levels and interpatient pharmacokinetic variance appear to be associated with primary resistance to AA with P.


Assuntos
Androstenos/administração & dosagem , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Prednisona/administração & dosagem , Neoplasias de Próstata Resistentes à Castração/tratamento farmacológico , Idoso , Androstenos/farmacologia , Intervalo Livre de Doença , Relação Dose-Resposta a Droga , Esquema de Medicação , Humanos , Masculino , Pessoa de Meia-Idade , Prednisona/uso terapêutico , Antígeno Prostático Específico/sangue , Neoplasias de Próstata Resistentes à Castração/sangue , Resultado do Tratamento
5.
Expert Rev Anticancer Ther ; 17(7): 625-633, 2017 07.
Artigo em Inglês | MEDLINE | ID: mdl-28532278

RESUMO

INTRODUCTION: Prostate cancer (PCa) is currently the second most common cancer affecting men worldwide. Metastatic castration-resistant prostate cancer (mCRPC) is the incurable form of PCa, carrying the poorest prognosis, and can develop from non-metastatic CRPC (M0 CRPC). CRPC is defined as progression of the disease with castrate level testosterone levels, achieved with primary androgen deprivation therapy (ADT). M0 CRPC is a highly heterogeneous disease process lacking clear standard of care therapies. Areas covered: In this review, a broad literature search was undertaken to explore data available for therapeutic options and guidelines in the management of M0 CRPC. Expert commentary: While there are compelling data for various therapeutics for the treatment of M0 CRPC, no clear standard of care is apparent at this time. Furthermore, technological advances in imaging may have a significant impact on this future of this disease state.


Assuntos
Antagonistas de Androgênios/uso terapêutico , Antineoplásicos Hormonais/uso terapêutico , Neoplasias de Próstata Resistentes à Castração/terapia , Progressão da Doença , Humanos , Masculino , Guias de Prática Clínica como Assunto , Neoplasias de Próstata Resistentes à Castração/patologia , Testosterona/metabolismo
6.
BMC Cancer ; 16(1): 744, 2016 Sep 22.
Artigo em Inglês | MEDLINE | ID: mdl-27658492

RESUMO

BACKGROUND: While programmed death 1 (PD-1) and programmed death-ligand 1 (PD-L1) checkpoint inhibitors have activity in a proportion of patients with advanced bladder cancer, strongly predictive and prognostic biomarkers are still lacking. In this study, we evaluated PD-L1 protein expression on circulating tumor cells (CTCs) isolated from patients with muscle invasive (MIBC) and metastatic (mBCa) bladder cancer and explore the prognostic value of CTC PD-L1 expression on clinical outcomes. METHODS: Blood samples from 25 patients with MIBC or mBCa were collected at UCSF and shipped to Epic Sciences. All nucleated cells were subjected to immunofluorescent (IF) staining and CTC identification by fluorescent scanners using algorithmic analysis. Cytokeratin expressing (CK)+ and (CK)-CTCs (CD45-, intact nuclei, morphologically distinct from WBCs) were enumerated. A subset of patient samples underwent genetic characterization by fluorescence in situ hybridization (FISH) and copy number variation (CNV) analysis. RESULTS: CTCs were detected in 20/25 (80 %) patients, inclusive of CK+ CTCs (13/25, 52 %), CK-CTCs (14/25, 56 %), CK+ CTC Clusters (6/25, 24 %), and apoptotic CTCs (13/25, 52 %). Seven of 25 (28 %) patients had PD-L1+ CTCs; 4 of these patients had exclusively CK-/CD45-/PD-L1+ CTCs. A subset of CTCs were secondarily confirmed as bladder cancer via FISH and CNV analysis, which revealed marked genomic instability. Although this study was not powered to evaluate survival, exploratory analyses demonstrated that patients with high PD-L1+/CD45-CTC burden and low burden of apoptotic CTCs had worse overall survival. CONCLUSIONS: CTCs are detectable in both MIBC and mBCa patients. PD-L1 expression is demonstrated in both CK+ and CK-CTCs in patients with mBCa, and genomic analysis of these cells supports their tumor origin. Here we demonstrate the ability to identify CTCs in patients with advanced bladder cancer through a minimally invasive process. This may have the potential to guide checkpoint inhibitor immune therapies that have been established to have activity, often with durable responses, in a proportion of these patients.

7.
Urol Oncol ; 34(8): 356-67, 2016 08.
Artigo em Inglês | MEDLINE | ID: mdl-26706121

RESUMO

Despite recent advances in the treatment of advanced prostate cancer (PCa), metastatic castrate-resistant PCa remains incurable at this time. The androgen receptor (AR) plays a key role in the development and progression of PCa, continuing to be active in most patients even after the development of castration resistance. Here, we aim to more closely review the mechanisms by which AR signaling is maintained, including AR overexpression/overamplification, intracrine androgen synthesis, AR mutations, and the development of AR splice variants. We also review therapies targeting each of these mechanisms. We also discuss the potential role of AR-CAG repeats and AR splice variants as potential biomarkers of response to hormonal manipulation therapies.


Assuntos
Antagonistas de Receptores de Andrógenos/uso terapêutico , Neoplasias de Próstata Resistentes à Castração/tratamento farmacológico , Receptores Androgênicos/metabolismo , Transdução de Sinais , Progressão da Doença , Humanos , Masculino , Isoformas de Proteínas/metabolismo
10.
J Clin Gastroenterol ; 49(4): 313-9, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25494362

RESUMO

GOAL: To determine whether Excellent bowel cleansing is superior to Good for the detection of adenomas. BACKGROUND: High quality colonoscopy requires Adequate bowel preparation. However, it is unknown whether adenoma detection differs between subcategories of Adequate cleansing. STUDY: We utilized a retrospective, cross-sectional study design to obtain data about patients undergoing colonoscopy at a single university center between August 31, 2011 and September 1, 2012. Primary outcome was adenoma detection rate (ADR), the percentage of patients with ≥1 adenoma. Secondary outcomes included adenomas per colonoscopy, adenoma distribution (proximal vs. distal), and detection of advanced adenomas, sessile serrated polyps (SSP), and cancer. RESULTS: The electronic medical record of 5113 consecutive colonoscopies with Good or Excellent preparation was queried for preparation quality, colonoscopy indication, demographics, medical history, and history of adenoma and colon cancer. Exclusion criteria were age below 18 years, inflammatory bowel disease, or familial polyposis. Adenoma detection was not superior with Excellent cleansing as compared with Good for ADR [respectively, 26% vs. 29%, odds ratio 0.97 (0.85, 1.11), P=0.618] or adenomas per colonoscopy [respectively, 0.437 vs. 0.499, incidence rate ratio (IRR) 0.98 (0.90, 1.07), P=0.705]. Excellent cleansing demonstrated superior detection of SSPs [IRR 1.66 (1.14, 2.40), P=0.008] and advanced adenomas [IRR 1.37 (1.09, 1.72), P=0.007] but not colon cancer [odds ratio 0.286 (0.083, 0.985), P=0.0474]. CONCLUSIONS: ADR is not significantly different between the Adequate subcategories of Excellent and Good. However, Excellent cleansing is associated with superior detection of advanced adenomas and SSPs. If confirmed, achieving an Excellent preparation may improve colonoscopy performance in the proximal colon where SSPs primarily occur.


Assuntos
Adenoma/diagnóstico , Catárticos/normas , Colonoscopia/normas , Neoplasias Colorretais/diagnóstico , Idoso , Pólipos do Colo/diagnóstico , Estudos Transversais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Razão de Chances , Estudos Retrospectivos
11.
Cell Cycle ; 12(9): 1371-84, 2013 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-23574725

RESUMO

Here, we interrogated head and neck cancer (HNSCC) specimens (n = 12) to examine if different metabolic compartments (oxidative vs. glycolytic) co-exist in human tumors. A large panel of well-established biomarkers was employed to determine the metabolic state of proliferative cancer cells. Interestingly, cell proliferation in cancer cells, as marked by Ki-67 immunostaining, was strictly correlated with oxidative mitochondrial metabolism (OXPHOS) and the uptake of mitochondrial fuels, as detected via MCT1 expression (p < 0.001). More specifically, three metabolic tumor compartments were delineated: (1) proliferative and mitochondrial-rich cancer cells (Ki-67+/TOMM20+/COX+/MCT1+); (2) non-proliferative and mitochondrial-poor cancer cells (Ki-67-/TOMM20-/COX-/MCT1-); and (3) non-proliferative and mitochondrial-poor stromal cells (Ki-67-/TOMM20-/COX-/MCT1-). In addition, high oxidative stress (MCT4+) was very specific for cancer tissues. Thus, we next evaluated the prognostic value of MCT4 in a second independent patient cohort (n = 40). Most importantly, oxidative stress (MCT4+) in non-proliferating epithelial cancer cells predicted poor clinical outcome (tumor recurrence; p < 0.0001; log-rank test), and was functionally associated with FDG-PET avidity (p < 0.04). Similarly, oxidative stress (MCT4+) in tumor stromal cells was specifically associated with higher tumor stage (p < 0.03), and was a highly specific marker for cancer-associated fibroblasts (p < 0.001). We propose that oxidative stress is a key hallmark of tumor tissues that drives high-energy metabolism in adjacent proliferating mitochondrial-rich cancer cells, via the paracrine transfer of mitochondrial fuels (such as L-lactate and ketone bodies). New antioxidants and MCT4 inhibitors should be developed to metabolically target "three-compartment tumor metabolism" in head and neck cancers. It is remarkable that two "non-proliferating" populations of cells (Ki-67-/MCT4+) within the tumor can actually determine clinical outcome, likely by providing high-energy mitochondrial "fuels" for proliferative cancer cells to burn. Finally, we also show that in normal mucosal tissue, the basal epithelial "stem cell" layer is hyper-proliferative (Ki-67+), mitochondrial-rich (TOMM20+/COX+) and is metabolically programmed to use mitochondrial fuels (MCT1+), such as ketone bodies and L-lactate. Thus, oxidative mitochondrial metabolism (OXPHOS) is a common feature of both (1) normal stem cells and (2) proliferating cancer cells. As such, we should consider metabolically treating cancer patients with mitochondrial inhibitors (such as Metformin), and/or with a combination of MCT1 and MCT4 inhibitors, to target "metabolic symbiosis."


Assuntos
Biomarcadores Tumorais/metabolismo , Neoplasias de Cabeça e Pescoço/metabolismo , Neoplasias de Cabeça e Pescoço/patologia , Transportadores de Ácidos Monocarboxílicos/metabolismo , Proteínas Musculares/metabolismo , Recidiva Local de Neoplasia/patologia , Células-Tronco Neoplásicas/patologia , Simportadores/metabolismo , Idoso , Idoso de 80 Anos ou mais , Diferenciação Celular , Proliferação de Células , Células Epiteliais/metabolismo , Células Epiteliais/patologia , Feminino , Fibroblastos/metabolismo , Fibroblastos/patologia , Glicólise , Humanos , Estimativa de Kaplan-Meier , Corpos Cetônicos/metabolismo , Ácido Láctico/metabolismo , Masculino , Proteínas de Membrana Transportadoras/metabolismo , Pessoa de Meia-Idade , Mitocôndrias/metabolismo , Proteínas do Complexo de Importação de Proteína Precursora Mitocondrial , Recidiva Local de Neoplasia/metabolismo , Estadiamento de Neoplasias , Células-Tronco Neoplásicas/metabolismo , Fosforilação Oxidativa , Estresse Oxidativo , Receptores de Superfície Celular/metabolismo
12.
J Interv Gastroenterol ; 2(4): 172-176, 2012 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-23687604

RESUMO

BACKGROUND AND AIMS: The diagnosis of intra-abdominal lymphadenopathy of is difficult, especially when no primary lesion has been identified. We aimed to evaluate the diagnostic yield of EUS-FNA cytology in patients with enlarged intra-abdominal lymph nodes of unknown etiology. PATIENT AND METHODS: 147 patients with abdominal lymphadenopathy on imaging in whom EUS-FNA was performed with a 22-gauge needle. Performance characteristics of EUS-FNA including the sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and accuracy were compared between the 2 groups. RESULTS: AThe location of the enlarged lymph nodes was the celiac axis (8.2%), peri-gastric (34%), peri-pancreatic (25.2%), peri-portal (27.9%), and other intra-abdominal locations (4.8%). The median number of EUS-FNA passes was 5. The final diagnosis were lymphoma in (n=27), metastatic adenocarcinoma (n=44) patients, other miscellaneous malignancies (n=22) and benign disease (n=54). The sensitivity, specificity, and accuracy of EUS-FNA were 89.7, 98.3, and 93.5% respectively. A false positive FNA result was present in only 1 case (0.7%); false negative FNA results were present in eight cases (5.8%). Lymph node morphologic features of roundness, echogenicity, and homogeneity on EUS were not a predictor of lymph node malignancy. CONCLUSION: In a retrospective cohort trial, EUS-FNA was found to be highly accurate and safe in diagnosing patients with intra-abdominal lymphadenopathy of unknown etiology.

13.
Mol Cell Biol ; 31(7): 1332-43, 2011 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-21282467

RESUMO

Helix-loop-helix (HLH) proteins play a profound role in the process of development and cellular differentiation. Among the HLH proteins expressed in differentiating erythroid cells are the ubiquitous proteins Myc, USF1, USF2, and TFII-I, as well as the hematopoiesis-specific transcription factor Tal1/SCL. All of these HLH proteins exhibit distinct functions during the differentiation of erythroid cells. For example, Myc stimulates the proliferation of erythroid progenitor cells, while the USF proteins and Tal1 regulate genes that specify the differentiated phenotype. This minireview summarizes the known activities of Myc, USF, TFII-I, and Tal11/SCL and discusses how they may function sequentially, cooperatively, or antagonistically in regulating expression programs during the differentiation of erythroid cells.


Assuntos
Diferenciação Celular , Células Eritroides/citologia , Células Eritroides/metabolismo , Sequências Hélice-Alça-Hélice , Animais , Diferenciação Celular/genética , Regulação da Expressão Gênica , Globinas/genética , Globinas/metabolismo , Humanos , Fatores de Transcrição/química , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo
14.
J Biol Chem ; 284(30): 20130-5, 2009 Jul 24.
Artigo em Inglês | MEDLINE | ID: mdl-19491096

RESUMO

Differentiation of erythroid cells is regulated by cell signaling pathways including those that change the intracellular concentration of calcium. Calcium-dependent proteases have been shown previously to process and regulate the activity of specific transcription factors. We show here that the protein levels of upstream stimulatory factor (USF) increase during differentiation of murine erythroleukemia (MEL) cells. USF was subject to degradation by the Ca(2+)-dependent protease m-calpain in undifferentiated but not in differentiated MEL cells. Treatment of MEL cells with the specific calpain inhibitor calpeptin increased the levels of USF and strongly induced expression of the adult alpha- and beta-globin genes. The induction of globin gene expression was associated with an increase in the association of USF and RNA po ly mer ase II with regulatory elements of the beta-globin gene locus. Calpeptin also induced high level alpha- and beta-globin gene expression in primary CD71-positive erythroid progenitor cells. The combined data suggest that inhibition of calpain activity is required for erythroid differentiation-associated increase in globin gene expression.


Assuntos
Dipeptídeos/farmacologia , Inibidores Enzimáticos/farmacologia , Células Eritroides/citologia , Globinas/genética , Fatores Estimuladores Upstream/metabolismo , Animais , Calpaína/antagonistas & inibidores , Calpaína/metabolismo , Diferenciação Celular , Células Eritroides/metabolismo , Feminino , Regulação da Expressão Gênica , Globinas/metabolismo , Leucemia Eritroblástica Aguda/genética , Leucemia Eritroblástica Aguda/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Murinae , Regiões Promotoras Genéticas , RNA Polimerase II/metabolismo , Fatores Estimuladores Upstream/genética
15.
FEBS J ; 274(23): 6065-73, 2007 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-17970752

RESUMO

Upstream stimulatory factor and TFII-I are ubiquitously expressed helix-loop-helix transcription factors that interact with E-box sequences and or initiator elements. We previously demonstrated that upstream stimulatory factor is an activator of beta-globin gene expression whereas TFII-I is a repressor. In the present study, we demonstrate that upstream stimulatory factor interacts with the coactivator p300 and that this interaction is restricted to erythroid cells expressing the adult beta-globin gene. Furthermore, we demonstrate that Suz12, a component of the polycomb repressor complex 2, is recruited to the beta-globin gene. Reducing expression of Suz12 significantly activates beta-globin gene expression in an erythroid cell line with an embryonic phenotype. Suz12 also interacts with the adult beta-globin gene during early stages of erythroid differentiation of mouse embryonic stem cells. Our data suggest that TFII-I contributes to the recruitment of the polycomb repressor complex 2 complex to the beta-globin gene. Together, these data demonstrate that the antagonistic activities of upstream stimulatory factor and TFII-I on beta-globin gene expression are mediated at least in part by protein complexes that render the promoter associated chromatin accessible or inaccessible for the transcription complex.


Assuntos
Regulação da Expressão Gênica no Desenvolvimento , Globinas/metabolismo , Proteínas Repressoras/metabolismo , Fatores de Transcrição TFII/metabolismo , Fatores Estimuladores Upstream/metabolismo , Animais , Proteínas de Transporte/metabolismo , Diferenciação Celular , Células Cultivadas , Imunoprecipitação da Cromatina , Células Eritroides/citologia , Globinas/genética , Histona Desacetilases/metabolismo , Humanos , Células K562 , Camundongos , Proteínas de Neoplasias , Proteínas Nucleares/metabolismo , Complexo Repressor Polycomb 2 , Proteínas do Grupo Polycomb , Regiões Promotoras Genéticas , Ligação Proteica , Interferência de RNA , RNA Interferente Pequeno/metabolismo , Células-Tronco/citologia , Fatores de Transcrição , Fatores de Transcrição de p300-CBP/metabolismo
16.
Mol Cell Biol ; 26(18): 6832-43, 2006 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-16943425

RESUMO

The human beta-globin genes are expressed in a developmental stage-specific manner in erythroid cells. Gene-proximal cis-regulatory DNA elements and interacting proteins restrict the expression of the genes to the embryonic, fetal, or adult stage of erythropoiesis. In addition, the relative order of the genes with respect to the locus control region contributes to the temporal regulation of the genes. We have previously shown that transcription factors TFII-I and USF interact with the beta-globin promoter in erythroid cells. Herein we demonstrate that reducing the activity of USF decreased beta-globin gene expression, while diminishing TFII-I activity increased beta-globin gene expression in erythroid cell lines. Furthermore, a reduction of USF activity resulted in a significant decrease in acetylated H3, RNA polymerase II, and cofactor recruitment to the locus control region and to the adult beta-globin gene. The data suggest that TFII-I and USF regulate chromatin structure accessibility and recruitment of transcription complexes in the beta-globin gene locus and play important roles in restricting beta-globin gene expression to the adult stage of erythropoiesis.


Assuntos
Regulação da Expressão Gênica no Desenvolvimento , Globinas/genética , Fatores de Transcrição TFII/metabolismo , Fatores Estimuladores Upstream/metabolismo , Animais , Diferenciação Celular , Células Cultivadas , Embrião de Mamíferos/citologia , Células Eritroides/citologia , Histona Desacetilases/metabolismo , Humanos , Células K562 , Camundongos , Modelos Genéticos , Ligação Proteica , RNA Polimerase II/metabolismo , Proteínas Repressoras/metabolismo , Células-Tronco/citologia , Transcrição Gênica , Fatores de Transcrição de p300-CBP/metabolismo
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