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1.
Cell Death Dis ; 15(7): 475, 2024 Jul 03.
Artigo em Inglês | MEDLINE | ID: mdl-38961053

RESUMO

Deregulated apoptosis signaling is characteristic for many cancers and contributes to leukemogenesis and treatment failure in B-cell precursor acute lymphoblastic leukemia (BCP-ALL). Apoptosis is controlled by different pro- and anti-apoptotic molecules. Inhibition of anti-apoptotic molecules like B-cell lymphoma 2 (BCL-2) has been developed as therapeutic strategy. Venetoclax (VEN), a selective BCL-2 inhibitor has shown clinical activity in different lymphoid malignancies and is currently evaluated in first clinical trials in BCP-ALL. However, insensitivity to VEN has been described constituting a major clinical concern. Here, we addressed and modeled VEN-resistance in BCP-ALL, investigated the underlying mechanisms in cell lines and patient-derived xenograft (PDX) samples and identified potential strategies to overcome VEN-insensitivity. Leukemia lines with VEN-specific resistance were generated in vitro and further characterized using RNA-seq analysis. Interestingly, gene sets annotated to the citric/tricarboxylic acid cycle and the respiratory electron transport chain were significantly enriched and upregulated, indicating increased mitochondrial metabolism in VEN-resistant ALL. Metabolic profiling showed sustained high mitochondrial metabolism in VEN-resistant lines as compared to control lines. Accordingly, primary PDX-ALL samples with intrinsic VEN-insensitivity showed higher oxygen consumption and ATP production rates, further highlighting that increased mitochondrial activity is a characteristic feature of VEN-resistant ALL. VEN-resistant PDX-ALL showed significant higher mitochondrial DNA content and differed in mitochondria morphology with significantly larger and elongated structures, further corroborating our finding of augmented mitochondrial metabolism upon VEN-resistance. Using Oligomycin, an inhibitor of the complex V/ATPase subunit, we found synergistic activity and apoptosis induction in VEN-resistant BCP-ALL cell lines and PDX samples, demonstrating that acquired and intrinsic VEN-insensitivity can be overcome by co-targeting BCL-2 and the OxPhos pathway. These findings of reprogrammed, high mitochondrial metabolism in VEN-resistance and synergistic activity upon co-targeting BCL-2 and oxidative phosphorylation strongly suggest further preclinical and potential clinical evaluation in VEN-resistant BCP-ALL.


Assuntos
Compostos Bicíclicos Heterocíclicos com Pontes , Resistencia a Medicamentos Antineoplásicos , Mitocôndrias , Fosforilação Oxidativa , Leucemia-Linfoma Linfoblástico de Células Precursoras , Sulfonamidas , Compostos Bicíclicos Heterocíclicos com Pontes/farmacologia , Humanos , Fosforilação Oxidativa/efeitos dos fármacos , Mitocôndrias/metabolismo , Mitocôndrias/efeitos dos fármacos , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Resistencia a Medicamentos Antineoplásicos/genética , Sulfonamidas/farmacologia , Leucemia-Linfoma Linfoblástico de Células Precursoras/metabolismo , Leucemia-Linfoma Linfoblástico de Células Precursoras/patologia , Leucemia-Linfoma Linfoblástico de Células Precursoras/tratamento farmacológico , Leucemia-Linfoma Linfoblástico de Células Precursoras/genética , Animais , Linhagem Celular Tumoral , Camundongos , Apoptose/efeitos dos fármacos , Antineoplásicos/farmacologia , Ensaios Antitumorais Modelo de Xenoenxerto , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Proteínas Proto-Oncogênicas c-bcl-2/genética
2.
Clin Respir J ; 18(1): e13721, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38286743

RESUMO

INTRODUCTION: Bronchoalveolar lavage (BAL) is frequently used in pulmonary medicine though it requires further optimization. Practical obstacles such as patient safety and procedural limitation have to date precluded large, controlled trials aimed at standardization of BAL procedure. Indeed, BAL guidelines are based on observational data. Innovative research methods are necessary to advance the clinical practice of BAL. METHODS: In our study, we evaluated the effect of injecting a gelatinized barium solution into different lobes and segments of cadaveric lungs. As the technique requires an irreversible injection into lung airspaces, it is not suitable for in vivo purposes. We measured the volume returned from BAL as well as the distribution of BAL injection via dissection. Segmental anatomic orientation was compared to a radiologist's impression of plain film radiographs taken of injected lungs. RESULTS: Mean injected volume distributions were greatest in the upper lobes and lowest in the lower lobes; mean ratios of injected volume distribution to lung lobe volume also followed this trend. Cannulated bronchi orders favored lower branches in the upper lobe and higher branches in the lower lobes. Segmental anatomy varied by the lung lobe injected and was most varied in the lower lobes. CONCLUSION: This novel gelatinized-barium injection technique provides a minimally complex method to yield clinically meaningful feedback on the performance of BAL. The technique is also adaptable to study of procedural parameters in the context of variable lung anatomies and pathologies.


Assuntos
Sulfato de Bário , Pulmão , Humanos , Bário , Lavagem Broncoalveolar , Pulmão/diagnóstico por imagem , Brônquios , Líquido da Lavagem Broncoalveolar , Broncoscopia/métodos
3.
Autops Case Rep ; 13: e2023455, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38034518

RESUMO

An enlarged left-sided supraclavicular node is a signal node for cancer metastasis. In such a case, the enlarged lymph node is often referred to as a Virchow node. The left-sided nature of the node is due to the drainage of the thoracic duct. So, the enlargement of a Virchow node is typically associated with malignancies, including gastrointestinal, pulmonary, and genitourinary carcinomas, in addition to lymphomas. This report documents a particularly unusual finding: bilateral Virchow nodes, representing metastasis of small-cell neuroendocrine carcinoma.

4.
Autops. Case Rep ; 13: e2023455, 2023. graf
Artigo em Inglês | LILACS-Express | LILACS | ID: biblio-1520264

RESUMO

ABSTRACT An enlarged left-sided supraclavicular node is a signal node for cancer metastasis. In such a case, the enlarged lymph node is often referred to as a Virchow node. The left-sided nature of the node is due to the drainage of the thoracic duct. So, the enlargement of a Virchow node is typically associated with malignancies, including gastrointestinal, pulmonary, and genitourinary carcinomas, in addition to lymphomas. This report documents a particularly unusual finding: bilateral Virchow nodes, representing metastasis of small-cell neuroendocrine carcinoma.

5.
IJU Case Rep ; 5(6): 423-426, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-36341183

RESUMO

Introduction: Liesegang rings are acellular, lamellar, concentric rings of organic or inorganic material naturally formed in both biologic and environmental systems. Description in human tissue is scarce. Liesegang rings have exclusively been identified in association with pathologic disease processes and thus are not typically considered in differential diagnosis. They are usually described with cystic or inflammatory lesions. Histologically, Liesegang rings show features that are also seen in sections of parasitic ova, larvae, psammoma bodies, and by radiology as calcifications in cystic diseases of the breast and kidney. Case presentation: We noted at autopsy of a 59-year-old diabetic woman multiple black "stones" in the renal medulla. Microscopic examination demonstrated these to contain Liesegang rings. Conclusion: Liesegang rings formation should be considered in the differential diagnosis of atypical appearing deposits in the kidneys and other tissues. They may play a role in the pathogenesis of kidney stones.

6.
Cancers (Basel) ; 13(20)2021 Oct 13.
Artigo em Inglês | MEDLINE | ID: mdl-34680272

RESUMO

To evaluate the safety and efficacy of transarterial chemoembolization with degradable starch microspheres (DSM-TACE) for the treatment of hepatocellular carcinoma (HCC) with a high tumor burden ineligible for or failing other palliative therapies, 121 patients from three European centers were included. Kaplan-Meier analysis was used for median overall survival (OS) and time to progression (TTP, mRECIST criteria) in months with a 95% confidence interval (95% CI). Uni- (UVA) and multivariate (MVA) analyses were performed using the Cox Proportional Hazard Model. The median OS of the study cohort was 15.5 (13.3-18.7) months. The UVA identified HCC lesions ≤10 cm, unilobar involvement, lower Child-Pugh class and Barcelona Clinic Liver Cancer (BCLC) stage, absence of vascular invasion, and extrahepatic metastases as factors for prolonged survival. MVA confirmed lesions of ≤10 cm and unilobar disease as independent OS factors. Median TTP was 9.5 (7.6-10.3) months. The best response was achieved after a median of 3 (range: 1-6) treatments with CR/PR/SD/PD in 13.5%/44.5%/25.2%/16.8%, respectively. DSM-TACE was well tolerated with no major clinical adverse events and only limited major laboratory events. Preserved liver function was observed after repetitive DSM-TACE treatments. Repetitive DSM-TACE is a safe, well-tolerated and effective treatment option for HCC patients with high tumor burden ineligible or failing other palliative therapies.

7.
Cureus ; 13(8): e16860, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34513437

RESUMO

We present a case of a 58-year-old female who presented initially to an outside institution with abdominal pain and was diagnosed on liver biopsy with a well-differentiated neuroendocrine tumor of an unknown primary source. She was referred to our academic institution for a second opinion after disease progression on the initial chemotherapy regimen. Through additional evaluation, diagnostics, and multi-disciplinary tumor board discussion she was diagnosed with metastases from a well-differentiated neuroendocrine neoplasm of the breast (NENB). Consequently, her treatment plan was modified leading to significant clinical and radiological improvement.

8.
Radiol Case Rep ; 16(11): 3445-3450, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34527120

RESUMO

Granulomatosis with polyangiitis formerly known as Wegener's granulomatosis was first described by German pathologist Friedrich Wegener in 1936. It is a multi-system necrotizing noncaseating granulomatous vasculitis which affects small to medium-sized vessels. It can involve any organ system, most commonly the lungs and kidneys. American College of Rheumatology requires 2 of 4 criteria for diagnosis: Positive biopsy for granulomatous vasculitis, urinary sediment with red blood cells, abnormal chest radiograph and oral/nasal inflammation. Here we present a case of Granulomatosis with polyangiitis with brief review of literature.

9.
J Exp Clin Cancer Res ; 40(1): 226, 2021 Jul 07.
Artigo em Inglês | MEDLINE | ID: mdl-34233711

RESUMO

BACKGROUND: Renal cell carcinomas (RCC) are characterized by the deregulation of several hundred hyperosmolality-responsive genes. High expression of a subset of these genes including the Ran binding protein 3 like (RANBP3L) is linked to a favorable prognostic outcome in RCC. However, the cellular function of RANBP3L remains largely unknown. METHODS: We used CRISPR/Cas9-mediated gene editing to generate functional deletions of the Ranbp3l and nuclear factor of activated T cells 5 (Nfat5) gene loci in a murine renal cell line. The NFAT5-KO cells were used to assess the regulation of Ranbp3l by NFAT5 using immunofluorescence, RNA-Seq and promoter assays. RANBP3L-deficient cells were analyzed for changes in cell morphology, proliferation, migration and colony-forming capacity using immunofluorescence and live cell imaging. RANPB3L-dependent changes in gene expression were identified by RNA-Seq. RESULTS: We show that NFAT5 directly regulates Ranpb3l under hyperosmotic conditions by binding its promoter. Functional analysis of RANBP3L-deficient cells revealed a loss of epithelial structure, an increased cell migration behavior and colony forming capacity, accompanied by massive alterations in gene expression, all of which are hallmarks for tumor cells. Strikingly, a RANBP3L dependent signature of 60 genes separated samples with clear cell carcinoma (KIRC) from papillary (KIRP), chromophobe renal carcinoma (KICH) and healthy tissue. CONCLUSIONS: Loss of RANBP3L induces a tumor like phenotype resembles RCC, especially KIRC, on the morphological and gene expression level and might promote tumor development and progression. Therapeutic reconstitution or elevation of osmoregulated RANBP3L expression might represent a novel treatment strategy for RCC or KIRC.


Assuntos
Carcinoma de Células Renais/metabolismo , Neoplasias Renais/metabolismo , Proteínas de Transporte Nucleocitoplasmático/metabolismo , Animais , Carcinoma de Células Renais/genética , Carcinoma de Células Renais/patologia , Linhagem Celular Tumoral , Progressão da Doença , Células Epiteliais/metabolismo , Células Epiteliais/patologia , Células HEK293 , Humanos , Neoplasias Renais/genética , Neoplasias Renais/patologia , Camundongos , Camundongos Knockout , Proteínas de Transporte Nucleocitoplasmático/genética , Fenótipo , Prognóstico , Transfecção
10.
BMJ Case Rep ; 14(5)2021 May 12.
Artigo em Inglês | MEDLINE | ID: mdl-33980555

RESUMO

Breast cancer is the most common cancer among women in the USA and rarely metastasises to the gastric wall. We present a case of a 69-year-old woman with medical history of stage II-B breast cancer who presented with epigastric abdominal pain and black tarry stools. CT scan of the abdomen showed moderate gastric wall thickening and ascites. The patient underwent an esophagogastroduodenoscopy (EGD) with endoscopic ultrasound (EUS) for a fine-needle biopsy, which was negative for malignancy. Based on her presentation, we kept a high index of suspicion for peritoneal carcinomatosis and malignancy. The patient underwent laparoscopic wedge resection of the gastric wall with biopsies of gastric wall and peritoneum. Both biopsies confirmed the diagnosis of metastatic invasive lobular breast carcinoma. Our case highlights the importance of diagnostic laparoscopy and EUS in the setting of negative EGD biopsy results with a high suspicion of breast cancer metastasis to gastric wall.


Assuntos
Neoplasias da Mama , Médicos , Neoplasias Gástricas , Idoso , Feminino , Humanos , Peritônio , Neoplasias Gástricas/diagnóstico por imagem
11.
Urol Case Rep ; 34: 101449, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33102130

RESUMO

Though rare, fibroepithelial polyps of the ureter consistently present with symptoms such as flank discomfort and may lead to renal failure. This often affects young adults and characteristically arises in the proximal ureter. The pathogenesis is unclear. Flank pain is the most common presenting symptom, which may create diagnostic confusion. Indeed, resection provides lasting relief which otherwise may elude patients who receive other treatments. Resection modality may be selected on a patient-by-patient basis. Here we present a case in which flank pain, and historical episodes of abdominal pain, were resolved by excision of a fibroepithelial polyp by a robotic assisted laparoscopic approach.

12.
Cancers (Basel) ; 12(2)2020 Feb 12.
Artigo em Inglês | MEDLINE | ID: mdl-32059438

RESUMO

Loss of von Hippel-Lindau (VHL) protein function can be found in more than 90% of patients with clear cell renal carcinoma (ccRCC). Mice lacking Vhl function in the kidneys have urine concentration defects due to postulated reduction of the hyperosmotic gradient. Hyperosmolality is a kidney-specific microenvironment and induces a unique gene expression pattern. This gene expression pattern is inversely regulated in patients with ccRCC with consequences for cancer-specific survival. Within this study, we tested the hypothesis if Vhl function influences the hyperosmolality induced changes in gene expression. We made use of the Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR)/Cas9 technology to inhibit functional Vhl expression in murine collecting duct cell line. Loss of Vhl function induced morphological changes within the cells similar to epithelial to mesenchymal transition like phenotype. Vhl-deficient cells migrated faster and proliferated slower compared to control cells. Gene expression profiling showed significant changes in gene expression patterns in Vhl-deficient cells compared to control cells. Several genes with unfavorable outcomes showed induced and genes with favorable outcomes for patients with renal cancer reduced gene expression level. Under hyperosmotic condition, the expression of several hyperosmolality induced genes, with favorable prognostic value, was downregulated in cells that do not express functional Vhl. Taken together, this study shows that Vhl interferes with hyperosmotic signaling pathway and hyperosmolality affected pathways might represent new promising targets.

13.
Cardiovasc Intervent Radiol ; 43(3): 402-410, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31705244

RESUMO

PURPOSE: To evalutate safety and efficacy of degradable starch microspheres (DSM) as embolic agent in transarterial chemoembolisation (TACE) of unresectable, locally extensive hepatocellular carcinoma (HCC). MATERIALS AND METHODS: In this retrospective study, 37 patients with intermediate to advanced HCC treated with ≥ 3 chemoembolisations with doxorubicin/epirubicin and DSM were analysed. Patients were treated with three consecutive chemoembolisations in 4-weekly intervals. Clinical parameters and laboratory findings were obtained from patient records before and after each intervention. Tumour response was assessed after every 3 embolisations by CT/MRI according to modified response evaluation criteria in solid tumours. RESULTS: Thirty-seven patients with HCC were treated with 177 DSM-TACEs (3-12/patient, mean 4.8). Disease stages according to the Barcelona Clinic Liver Cancer (BCLC) staging system were: 27 × B, 9 × C, 1 × D. Five patients had uninodular, 32 multinodular (23 bilobar) disease. Three patients had portal vein invasion. Apart from one possibly procedure-related grade 3 complication, only grade 1 adverse events occurred. These were pain reacting to analgesics (23%), transient nausea (11%), vomiting (3%) and post-embolisation syndrome (4%). Transient laboratory changes were bone marrow toxicity (29%) and increase in INR (14%), creatinine (8%) or bilirubin (38%). Tumour response was objective response rate 49%, disease control rate 83%. Median survival was 19 months: 22 months for BCLC stage B and 6.7 months for BCLC stages C + D. Responders had a significantly better prognosis than non-responders. CONCLUSION: DSM-TACE of HCC is safe even in patients with advanced disease stages. Tumour response and survival rates were encouraging in our series of patients with locally extensive disease.


Assuntos
Antibióticos Antineoplásicos/administração & dosagem , Carcinoma Hepatocelular/terapia , Quimioembolização Terapêutica/métodos , Epirubicina/administração & dosagem , Neoplasias Hepáticas/terapia , Amido/administração & dosagem , Idoso , Carcinoma Hepatocelular/diagnóstico por imagem , Feminino , Humanos , Fígado/diagnóstico por imagem , Neoplasias Hepáticas/diagnóstico por imagem , Imageamento por Ressonância Magnética , Masculino , Imagem Multimodal , Prognóstico , Critérios de Avaliação de Resposta em Tumores Sólidos , Estudos Retrospectivos , Tomografia Computadorizada por Raios X , Resultado do Tratamento
14.
PLoS One ; 14(5): e0216862, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31086407

RESUMO

Polytrauma (PT) is a life-threatening disease and a major global burden of injury. Mesenchymal stromal cells (MSC) might be a therapeutic option for PT patients due to their anti-inflammatory and regenerative potential. We hypothesised that the inflammatory response of MSC is similar after exposure to selected trauma-relevant factors to sera from PT patients (PTS). Therefore, we investigated the effects of a mixture of defined factors, supposed to play a role on MSC in the early phase of PT. Additionally, in a translational approach we investigated the effect of serum from PT patients on MSC in vitro. MSC were incubated with a PT cocktail in physiological (PTCL) and supra-physiological (PTCH) concentrations or PTS. The effect on gene expression and protein secretion of MSC was analysed by RNA sequencing, ELISA and Multiplex assays of cell culture supernatant. Stimulation of MSC with PTCH, PTCL or IL1B led to significant up- or downregulation of 470, 183 and 469 genes compared to unstimulated MSC at 6 h. The intersection of differentially expressed genes in these groups was very high (92% overlap with regard to the PTCL group; treated for 6 h). Cytokine secretion profile of MSC revealed that IL1B mimics the effect of a more complex PT cocktail as well. However, there was only a minor proportion of overlapping differentially expressed genes between the MSC group stimulated with early times of PTS and the MSC group stimulated with PTCH, PTCL and IL1B. In conclusion, the effect of sera from PT patients on MSC activation cannot be simulated by the chosen trauma-relevant factors. Furthermore, we conclude that while IL1B might be useful to prime MSC prior to therapeutic application, it might not be as useful for the in vitro study of functional properties of MSC in the context of PT.


Assuntos
Inflamação/imunologia , Células-Tronco Mesenquimais/imunologia , Traumatismo Múltiplo/imunologia , Adulto , Células Cultivadas , Citocinas/sangue , Citocinas/imunologia , Feminino , Humanos , Inflamação/sangue , Inflamação/complicações , Inflamação/patologia , Masculino , Células-Tronco Mesenquimais/patologia , Pessoa de Meia-Idade , Traumatismo Múltiplo/sangue , Traumatismo Múltiplo/complicações , Traumatismo Múltiplo/patologia , Adulto Jovem
15.
Target Oncol ; 10(1): 77-84, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-24824730

RESUMO

Data regarding the expression of epidermal growth factor receptor (EGFR) in melanoma and its role in the tumor biology are conflicting. In BRAF V600-mutant melanomas, the expression of EGFR has been associated with acquired resistance to BRAF inhibitors. In this study, we assessed EGFR expression and downstream signaling activity in a panel of melanoma cell lines and we investigated the effects of the BRAF inhibitor vemurafenib on expression of EGFR and its downstream effectors in a subgroup of BRAF-mutant melanoma cells. Three out of 10 melanoma cell lines expressed EGFR. Downstream signaling via ERK and AKT was responsive to either stimulation by EGF or inhibition by erlotinib. Constitutive activation of ERK occurred in all the cell lines investigated whereas constitutive activation of AKT only in three cell lines. Constitutive activation of ERK and AKT was independent from EGFR expression. Vemurafenib did not affect EGFR expression in general, but it increased EGFR phosphorylation in the cell line SkMel5. Induced EGFR phosphorylation was sensitive to treatment with erlotinib. Vemurafenib efficiently blocked ERK activation in all the BRAF-mutant cell lines tested, whereas its effects on AKT activation were dissimilar in the different cell lines. Our data suggest that EGFR is functional but usually inactive in EGFR high-expressing cell lines. Basal EGFR expression unlikely represents a biomarker for predicting the sensitivity to vemurafenib in melanoma, but EGFR activation might represent a mechanism of vemurafenib resistance in a subset of melanoma cells.


Assuntos
Antineoplásicos/farmacologia , Receptores ErbB/metabolismo , Indóis/farmacologia , Melanoma/metabolismo , Transdução de Sinais/efeitos dos fármacos , Neoplasias Cutâneas/metabolismo , Sulfonamidas/farmacologia , Western Blotting , Linhagem Celular Tumoral , Resistencia a Medicamentos Antineoplásicos/fisiologia , Humanos , Microscopia de Fluorescência , Reação em Cadeia da Polimerase em Tempo Real , Vemurafenib
17.
Int J Pharm ; 441(1-2): 643-7, 2013 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-23117025

RESUMO

Multiple emulsions offer various applications in a wide range of fields such as pharmaceutical, cosmetics and food technology. Two features are known to yield a great influence on multiple emulsion quality and utility as encapsulation efficiency and prolonged stability. To achieve a prolonged stability, the production of the emulsions has to be observed and controlled, preferably in line. In line measurements provide available parameters in a short time frame without the need for the sample to be removed from the process stream, thereby enabling continuous process control. In this study, information about the physical state of multiple emulsions obtained from dielectric spectroscopy (DS) is evaluated for this purpose. Results from dielectric measurements performed in line during the production cycle are compared to theoretically expected results and to well established off line measurements. Thus, a first step to include the production of multiple emulsions into the process analytical technology (PAT) guidelines of the Food and Drug Administration (FDA) is achieved. DS proved to be beneficial in determining the crucial stopping criterion, which is essential in the production of multiple emulsions. The stopping of the process at a less-than-ideal point can severely lower the encapsulation efficiency and the stability, thereby lowering the quality of the emulsion. DS is also expected to provide further information about the multiple emulsion like encapsulation efficiency.


Assuntos
Espectroscopia Dielétrica/métodos , Composição de Medicamentos/métodos , Emulsões/química , Guias como Assunto , Estabilidade de Medicamentos , Emulsões/normas , Óleos/química , Tecnologia Farmacêutica/métodos , Estados Unidos , United States Food and Drug Administration , Água/química
18.
Cell ; 148(5): 1001-14, 2012 Mar 02.
Artigo em Inglês | MEDLINE | ID: mdl-22385964

RESUMO

Checkpoints that limit stem cell self-renewal in response to DNA damage can contribute to cancer protection but may also promote tissue aging. Molecular components that control stem cell responses to DNA damage remain to be delineated. Using in vivo RNAi screens, we identified basic leucine zipper transcription factor, ATF-like (BATF) as a major component limiting self-renewal of hematopoietic stem cells (HSCs) in response to telomere dysfunction and γ-irradiation. DNA damage induces BATF in a G-CSF/STAT3-dependent manner resulting in lymphoid differentiation of HSCs. BATF deletion improves HSC self-renewal and function in response to γ-irradiation or telomere shortening but results in accumulation of DNA damage in HSCs. Analysis of bone marrow from patients with myelodysplastic syndrome supports the conclusion that DNA damage-dependent induction of BATF is conserved in human HSCs. Together, these results provide experimental evidence that a BATF-dependent differentiation checkpoint limits self-renewal of HSCs in response to DNA damage.


Assuntos
Pontos de Checagem do Ciclo Celular , Diferenciação Celular , Senescência Celular , Dano ao DNA , Células-Tronco Hematopoéticas/citologia , Células-Tronco Hematopoéticas/metabolismo , Animais , Humanos , Camundongos , Camundongos Endogâmicos C57BL , Organismos Livres de Patógenos Específicos , Encurtamento do Telômero
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