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1.
Cells ; 9(6)2020 06 18.
Artigo em Inglês | MEDLINE | ID: mdl-32570839

RESUMO

NOTCH signaling represents a promising therapeutic target in chronic lymphocytic leukemia (CLL). We compared the anti-neoplastic effects of the nuclear NOTCH2 inhibitor gliotoxin and the pan-NOTCH γ-secretase inhibitor RO4929097 in primary CLL cells with special emphasis on the individual roles of the different NOTCH receptors. Gliotoxin rapidly induced apoptosis in all CLL cases tested, whereas RO4929097 exerted a variable and delayed effect on CLL cell viability. Gliotoxin-induced apoptosis was associated with inhibition of the NOTCH2/FCER2 (CD23) axis together with concomitant upregulation of the NOTCH3/NR4A1 axis. In contrast, RO4929097 downregulated the NOTCH3/NR4A1 axis and counteracted the spontaneous and gliotoxin-induced apoptosis. On the cell surface, NOTCH3 and CD23 expression were mutually exclusive, suggesting that downregulation of NOTCH2 signaling is a prerequisite for NOTCH3 expression in CLL cells. ATAC-seq confirmed that gliotoxin targeted the canonical NOTCH signaling, as indicated by the loss of chromatin accessibility at the potential NOTCH/CSL site containing the gene regulatory elements. This was accompanied by a gain in accessibility at the NR4A1, NFκB, and ATF3 motifs close to the genes involved in B-cell activation, differentiation, and apoptosis. In summary, these data show that gliotoxin recovers a non-canonical tumor-suppressing NOTCH3 activity, indicating that nuclear NOTCH2 inhibitors might be beneficial compared to pan-NOTCH inhibitors in the treatment of CLL.


Assuntos
Gliotoxina/farmacologia , Leucemia Linfocítica Crônica de Células B/tratamento farmacológico , Leucemia Linfocítica Crônica de Células B/metabolismo , Receptor Notch2/antagonistas & inibidores , Receptor Notch3/agonistas , Adulto , Idoso , Idoso de 80 Anos ou mais , Secretases da Proteína Precursora do Amiloide/antagonistas & inibidores , Antineoplásicos/administração & dosagem , Antineoplásicos/farmacologia , Apoptose/efeitos dos fármacos , Benzazepinas/administração & dosagem , Benzazepinas/farmacologia , Sobrevivência Celular/efeitos dos fármacos , Relação Dose-Resposta a Droga , Regulação para Baixo/efeitos dos fármacos , Feminino , Gliotoxina/administração & dosagem , Humanos , Lectinas Tipo C/antagonistas & inibidores , Leucemia Linfocítica Crônica de Células B/patologia , Masculino , Pessoa de Meia-Idade , Membro 1 do Grupo A da Subfamília 4 de Receptores Nucleares/agonistas , Membro 1 do Grupo A da Subfamília 4 de Receptores Nucleares/genética , Membro 1 do Grupo A da Subfamília 4 de Receptores Nucleares/metabolismo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Receptor Notch2/genética , Receptor Notch2/metabolismo , Receptor Notch3/genética , Receptor Notch3/metabolismo , Receptores de IgE/antagonistas & inibidores , Elementos Reguladores de Transcrição , Transdução de Sinais/efeitos dos fármacos , Células Tumorais Cultivadas
2.
Br J Cancer ; 123(2): 240-251, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32418995

RESUMO

BACKGROUND: High UGT2B17 is associated with poor prognosis in untreated chronic lymphocytic leukaemia (CLL) patients and its expression is induced in non-responders to fludarabine-containing regimens. We examined whether UGT2B17, the predominant lymphoid glucuronosyltransferase, affects leukaemic drug response and is involved in the metabolic inactivation of anti-leukaemic agents. METHODS: Functional enzymatic assays and patients' plasma samples were analysed by mass-spectrometry to evaluate drug inactivation by UGT2B17. Cytotoxicity assays and RNA sequencing were used to assess drug response and transcriptome changes associated with high UGT2B17 levels. RESULTS: High UGT2B17 in B-cell models led to reduced sensitivity to fludarabine, ibrutinib and idelalisib. UGT2B17 expression in leukaemic cells involved a non-canonical promoter and was induced by short-term treatment with these anti-leukaemics. Glucuronides of both fludarabine and ibrutinib were detected in CLL patients on respective treatment, however UGT2B17 conjugated fludarabine but not ibrutinib. AMP-activated protein kinase emerges as a pathway associated with high UGT2B17 in fludarabine-treated patients and drug-treated cell models. The expression changes linked to UGT2B17 exposed nuclear factor kappa B as a key regulatory hub. CONCLUSIONS: Data imply that UGT2B17 represents a mechanism altering drug response in CLL through direct inactivation but would also involve additional mechanisms for drugs not inactivated by UGT2B17.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/farmacologia , Biomarcadores Farmacológicos/metabolismo , Glucuronosiltransferase/genética , Leucemia Linfocítica Crônica de Células B/tratamento farmacológico , Antígenos de Histocompatibilidade Menor/genética , Adenina/efeitos adversos , Adenina/análogos & derivados , Adenina/farmacologia , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Linfócitos B/efeitos dos fármacos , Linfócitos B/patologia , Feminino , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , Leucemia Linfocítica Crônica de Células B/sangue , Leucemia Linfocítica Crônica de Células B/genética , Leucemia Linfocítica Crônica de Células B/patologia , Masculino , Espectrometria de Massas , Pessoa de Meia-Idade , NF-kappa B/genética , Piperidinas/efeitos adversos , Piperidinas/farmacologia , Purinas/efeitos adversos , Purinas/farmacologia , Quinazolinonas/efeitos adversos , Quinazolinonas/farmacologia , Vidarabina/efeitos adversos , Vidarabina/análogos & derivados , Vidarabina/farmacologia
3.
N Biotechnol ; 54: 1-12, 2020 Jan 25.
Artigo em Inglês | MEDLINE | ID: mdl-31400479

RESUMO

Rabbit mesenchymal stem cells (rMSCs) are promising agents for the preservation of genetic biodiversity in domestic rabbit breeds. However, rMSCs must meet certain requirements to be used for cryopreservation in animal gene banks. Currently, there are numerous discrepancies in the published data regarding the rMSC phenotype, which may complicate efforts to evaluate their purity and suitability for reuse after cryopreservation in gene and tissue banks. We propose a combined approach (flow cytometry, PCR, differentiation and ultrastructure studies) for the characterization and recovery of rMSCs after cryopreservation. Flow cytometric analyses of rMSCs confirmed the expression of CD29, CD44, vimentin, desmin and α-SMA. RT-PCR revealed the expression of other markers at the mRNA level (SSEA-4, CD73, CD90, CD105, CD146 and CD166). rMSCs showed efficient multilineage differentiation into adipo-, chondro- and osteogenic lineages, SOX2 expression (pluripotency) and typical MSC morphology and ultrastructure. The confirmed rMSCs were subsequently used for cryopreservation. Efficient recovery of rMSCs after cryogenic freezing was demonstrated by high cell viability, normal ultrastructure of reseeded rMSCs, high expression of CD29 and CD44 and lineage differentiation capacity. The proposed combined approach could be used for characterization, cryopreservation and recovery of rMSCs as genetic resources for native rabbit breeds.


Assuntos
Bancos de Espécimes Biológicos/normas , Células da Medula Óssea/citologia , Células-Tronco Mesenquimais/citologia , Coelhos/genética , Animais , Antígenos CD/metabolismo , Células da Medula Óssea/metabolismo , Criopreservação , Células-Tronco Mesenquimais/metabolismo , Fenótipo , RNA Mensageiro/genética , Coelhos/classificação , Reação em Cadeia da Polimerase Via Transcriptase Reversa
4.
Nat Chem Biol ; 15(3): 232-240, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-30692684

RESUMO

The Bruton tyrosine kinase (BTK) inhibitor ibrutinib has substantially improved therapeutic options for chronic lymphocytic leukemia (CLL). Although ibrutinib is not curative, it has a profound effect on CLL cells and may create new pharmacologically exploitable vulnerabilities. To identify such vulnerabilities, we developed a systematic approach that combines epigenome profiling (charting the gene-regulatory basis of cell state) with single-cell chemosensitivity profiling (quantifying cell-type-specific drug response) and bioinformatic data integration. By applying our method to a cohort of matched patient samples collected before and during ibrutinib therapy, we identified characteristic ibrutinib-induced changes that provide a starting point for the rational design of ibrutinib combination therapies. Specifically, we observed and validated preferential sensitivity to proteasome, PLK1, and mTOR inhibitors during ibrutinib treatment. More generally, our study establishes a broadly applicable method for investigating treatment-specific vulnerabilities by integrating the complementary perspectives of epigenetic cell states and phenotypic drug responses in primary patient samples.


Assuntos
Tirosina Quinase da Agamaglobulinemia/metabolismo , Leucemia Linfocítica Crônica de Células B/tratamento farmacológico , Adenina/análogos & derivados , Tirosina Quinase da Agamaglobulinemia/antagonistas & inibidores , Proteínas de Ciclo Celular/metabolismo , Cromatina/fisiologia , Combinação de Medicamentos , Resistencia a Medicamentos Antineoplásicos/genética , Epigênese Genética/genética , Epigenômica/métodos , Humanos , Leucemia Linfocítica Crônica de Células B/genética , Piperidinas , Inibidores de Proteínas Quinases , Proteínas Serina-Treonina Quinases/metabolismo , Proteínas Tirosina Quinases/metabolismo , Proteínas Tirosina Quinases/fisiologia , Proteínas Proto-Oncogênicas/metabolismo , Pirazóis/farmacologia , Pirimidinas/farmacologia , Transdução de Sinais , Análise de Célula Única/métodos , Serina-Treonina Quinases TOR/metabolismo , Quinase 1 Polo-Like
5.
Wien Klin Wochenschr ; 130(17-18): 517-529, 2018 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-30006759

RESUMO

In 2008 the Ludwig Boltzmann Cluster Oncology (LBC ONC) was established on the basis of two previous Ludwig Boltzmann Institutes working in the field of hematology and cancer research. The general aim of the LBC ONC is to improve treatment of hematopoietic neoplasms by eradicating cancer-initiating and disease-propagating cells, also known as leukemic stem cells (LSC) in the context of leukemia. In a first phase, the LBC ONC characterized the phenotype and molecular aberration profiles of LSC in various malignancies. The LSC phenotypes were established in acute and chronic myeloid leukemia, in acute lymphoblastic leukemia and in chronic lymphocytic leukemia. In addition, the concept of preleukemic (premalignant) neoplastic stem cells (pre-L-NSC) was coined by the LBC ONC and was tested in myelodysplastic syndromes and myeloproliferative neoplasms. Phenotypic characterization of LSC provided a solid basis for their purification and for the characterization of specific target expression profiles. In a second phase, molecular markers and targets were validated. This second phase is ongoing and should result in the development of new diagnostics parameters and novel, more effective, LSC-eradicating, treatment strategies; however, many issues still remain to be solved, such as sub-clonal evolution, LSC niche interactions, immunologic control of LSC, and LSC resistance. In the forthcoming years, the LBC ONC will concentrate on developing LSC-eradicating strategies, with special focus on LSC resistance, precision medicine and translation of LSC-eradicating concepts into clinical application.


Assuntos
Leucemia Mielogênica Crônica BCR-ABL Positiva , Humanos , Células-Tronco Neoplásicas
6.
Biotechnol Prog ; 34(5): 1278-1289, 2018 09.
Artigo em Inglês | MEDLINE | ID: mdl-29882300

RESUMO

Rabbits have many hereditary diseases common to humans and are therefore a valuable model for regenerative disease and hematopoietic stem cell (HSC) therapies. Currently, there is no substantial data on the isolation and/or enrichment of rabbit HSCs. This study was initiated to evaluate the efficiency of the commercially available anti-CD34 and anti-CD133 antibodies for the detection and potential enrichment of rabbit HSCs from peripheral blood. PBMCs from rabbit and human blood were labelled with different clones of anti-human CD34 monoclonal antibodies (AC136, 581, and 8G12) and rabbit polyclonal CD34 antibody (pCD34) and anti-human CD133 monoclonal antibodies (AC133 and 293C3). Flow cytometry showed a higher percentage of rabbit CD34+ cells labelled by AC136 in comparison to the clone 581 and pCD34 (P < 0.01). A higher percentage of rabbit CD133+ cells were also detected by 293C3 compared to the AC133 clone (P < 0.01). Therefore, AC136 clone was used for the indirect immunomagnetic enrichment of rabbit CD34+ cells using magnetic-activated cell sorting (MACS). The enrichment of the rabbit CD34+ cells after sorting was low in comparison to human samples (2.4% vs. 39.6%). PCR analyses confirmed the efficient enrichment of human CD34+ cells and the low expression of CD34 mRNA in rabbit positive fraction. In conclusion, the tested antibodies might be suitable for detection, but not for sorting the rabbit CD34+ HSCs and new specific anti-rabbit CD34 antibodies are needed for efficient enrichment of rabbit HSCs. © 2018 American Institute of Chemical Engineers Biotechnol. Prog., 2018 © 2018 American Institute of Chemical Engineers Biotechnol. Prog., 34:1278-1289, 2018.


Assuntos
Antígeno AC133/imunologia , Anticorpos/imunologia , Antígenos CD34/imunologia , Células-Tronco Hematopoéticas/imunologia , Animais , Citometria de Fluxo , Coelhos
7.
Front Pharmacol ; 8: 319, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28736522

RESUMO

Deregulation of NOTCH2 signaling is implicated in a wide variety of human neoplasias. The current concept of targeting NOTCH is based on using gamma secretase inhibitors (GSI) to regulate the release of the active NOTCH intracellular domain. However, the clinical outcome of GSI remains unsatisfactory. Therefore we analyzed human solid tumor derived cell lines for their nuclear NOTCH activity and evaluated the therapeutic potential of the NOTCH2 transactivation inhibitor gliotoxin in comparison to the representative GSI DAPT. Electrophoretic mobility shift assays (EMSA) were used as a surrogate method for the detection of NOTCH/CSL transcription factor complexes. The effect of gliotoxin on cell viability and its clinical relevance was evaluated in vitro and in a melanoma xenograft mouse model. Cell lines derived from melanoma (518A2), hepatocellular carcinoma (SNU398, HCC-3, Hep3B), and pancreas carcinoma (PANC1) express high amounts of nuclear NOTCH2. Gliotoxin efficiently induced apoptosis in these cell lines whereas the GSI DAPT was ineffective. The specificity of gliotoxin was demonstrated in the well differentiated nuclear NOTCH negative cell line Huh7, which was resistant to gliotoxin treatment in vitro. In xenotransplanted 518A2 melanomas, a single day dosing schedule of gliotoxin was well tolerated without any study limiting side effects. Gliotoxin significantly reduced the tumor volume in early (83 mm3 vs. 115 mm3, p = 0.008) as well as in late stage (218 mm3 vs. 576 mm3, p = 0.005) tumor models. In conclusion, NOTCH2 appears to be a key target of gliotoxin in human neoplasias and gliotoxin deserves further evaluation as a potential therapeutic agent in cancer management.

8.
Br J Haematol ; 160(5): 618-29, 2013 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-23278106

RESUMO

Chronic lymphocytic leukaemia (CLL) cells express constitutively activated NOTCH2 in a protein kinase C (PKC)- dependent manner. The transcriptional activity of NOTCH2 correlates not only with the expression of its target gene FCER2 (CD23) but is also functionally linked with CLL cell viability. In the majority of CLL cases, DNA-bound NOTCH2 complexes are less sensitive to the γ-secretase inhibitor (GSI) DAPT. Therefore, we searched for compounds that interfere with NOTCH2 signalling at the transcription factor level. Using electrophoretic mobility shift assays (EMSA), we identified the Aspergillum-derived secondary metabolite gliotoxin as a potent NOTCH2 transactivation inhibitor. Gliotoxin completely blocked the formation of DNA-bound NOTCH2 complexes in CLL cells independent of their sensitivity to DAPT. The inhibition of NOTCH2 signalling by gliotoxin was associated with down regulation of CD23 (FCER) expression and induction of apoptosis. Short time exposure of CLL cells indicated that the early apoptotic effect of gliotoxin is independent of proteasome regulated nuclear factor κB activity, and is associated with up regulation of NOTCH3 and NR4A1 expression. Gliotoxin could overcome the supportive effect of primary bone marrow stromal cells in an ex vivo CLL microenvironment model. In conclusion, we identified gliotoxin as a potent NOTCH2 inhibitor with a promising therapeutic potential in CLL.


Assuntos
Apoptose/efeitos dos fármacos , Regulação Leucêmica da Expressão Gênica/efeitos dos fármacos , Gliotoxina/farmacologia , Leucemia Linfocítica Crônica de Células B/patologia , Proteínas de Neoplasias/antagonistas & inibidores , Receptor Notch2/antagonistas & inibidores , Ativação Transcricional/efeitos dos fármacos , Idoso , Idoso de 80 Anos ou mais , Linhagem Celular Tumoral/efeitos dos fármacos , Linhagem Celular Tumoral/patologia , Técnicas de Cocultura , Análise Mutacional de DNA , Depressão Química , Feminino , Humanos , Cadeias Pesadas de Imunoglobulinas/genética , Concentração Inibidora 50 , Leucemia Linfocítica Crônica de Células B/sangue , Masculino , Pessoa de Meia-Idade , NF-kappa B/metabolismo , Proteínas de Neoplasias/biossíntese , Proteínas de Neoplasias/genética , Membro 1 do Grupo A da Subfamília 4 de Receptores Nucleares/biossíntese , Membro 1 do Grupo A da Subfamília 4 de Receptores Nucleares/genética , Complexo de Endopeptidases do Proteassoma/metabolismo , Receptor Notch3 , Receptores Notch/biossíntese , Receptores Notch/genética , Células Estromais/fisiologia , Fatores de Transcrição/fisiologia , Células Tumorais Cultivadas/efeitos dos fármacos , Células Tumorais Cultivadas/patologia
9.
Wien Klin Wochenschr ; 122(13-14): 423-36, 2010 Jul.
Artigo em Alemão | MEDLINE | ID: mdl-20645015

RESUMO

Biological features of tumor cells relevant to progression, metastasis, and prognosis in cancer patients have been investigated for many years. During the past few years, the concept of tumor stem cells has gained widespread acceptance. The cancer stem cell (CSC) model is based on the observation that continuous growth of tumors depends on a small population of immature neoplastic cells with unlimited proliferative potential. In contrast to these CSC, more mature clonal cells in the same neoplasm undergo apoptosis and die after a variable number of cell divisions. The self-renewal capacity of CSC plays a central role in this scenario and enables permanent tumor cell repopulation in vivo in patients as well as in experimental animals, e.g., immunodeficient mice. Based on the stem cell concept, it is clear that the success of an anti-neoplastic approach depends on efficient targeting and elimination of CSC. An important aspect of CSC is their intrinsic resistance against conventional drugs. Therefore, a major focus in current research is molecular targets and their expression in CSC, with the goal to use targeted drugs for CSC elimination. It is the hope for the future that therapeutic approaches involving CSC-targeting concepts will lead to sustained remission and thus improvement of prognosis in leukemia and cancer patients.


Assuntos
Antineoplásicos/uso terapêutico , Leucemia/diagnóstico , Leucemia/tratamento farmacológico , Neoplasias/diagnóstico , Neoplasias/tratamento farmacológico , Células-Tronco Neoplásicas/patologia , Ensaio Tumoral de Célula-Tronco , Animais , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Apoptose/efeitos dos fármacos , Apoptose/fisiologia , Divisão Celular/efeitos dos fármacos , Divisão Celular/fisiologia , Resistencia a Medicamentos Antineoplásicos , Humanos , Leucemia/patologia , Camundongos , Camundongos Nus , Neoplasias/patologia , Células-Tronco Neoplásicas/efeitos dos fármacos , Prognóstico
10.
Blood ; 116(14): 2513-21, 2010 Oct 07.
Artigo em Inglês | MEDLINE | ID: mdl-20576813

RESUMO

Evidence suggests that tumor microenvironment is critically involved in supporting survival of chronic lymphocytic leukemia (CLL) cells. However, the molecular mechanisms of this effect and the clinical significance are not fully understood. We applied a microenvironment model to explore the interaction between CLL cells and stromal cells and to elucidate the role of phosphatidylinositol 3 kinase (PI3-K)/Akt/phosphatase and tensin homolog detected on chromosome 10 (PTEN) cascade in this process and its in vivo relevance. Primary human stromal cells from bone marrow, lymph nodes, and spleen significantly inhibited spontaneous apoptosis of CLL cells. Pan-PI3-K inhibitors (LY294002, wortmannin, PI-103), isotype-specific inhibitors of p110α, p110ß, p110γ, and small interfering RNA against PI3-K and Akt1 counteracted the antiapoptotic effect of the stromal cells. Induction of apoptosis was associated with a decrease in phosphatidylinositol-3,4,5-triphosphate, PI3-K-p85, and dephosphorylation of phosphatidylinositol-dependent kinase-1 (PDK-1), Akt1, and PTEN. Freshly isolated peripheral blood mononuclear cells from patients with CLL (n = 44) showed significantly higher levels of phosphorylated Akt1, PDK-1, PTEN, and CK2 than healthy persons (n = 8). CK2 inhibitors (4,5,6,7-tetrabromo-1H-benzotriazole, apigenin, and 5,6-dichloro-1-ß-D-ribofuranosylbenzimidazol) decreased phosphorylation of PTEN and Akt, induced apoptosis in CLL cells, and enhanced the response to fludarabine. In conclusion, bone marrow microenvironment modulates the PI3-K/Akt/PTEN cascade and prevents apoptosis of CLL cells. Combined inhibition of PI3-K/Akt and recovery of PTEN activity may represent a novel therapeutic concept for CLL.


Assuntos
Apoptose , Células da Medula Óssea/metabolismo , Leucemia Linfocítica Crônica de Células B/metabolismo , PTEN Fosfo-Hidrolase/metabolismo , Fosfatidilinositol 3-Quinase/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Células da Medula Óssea/patologia , Caseína Quinase II/metabolismo , Células Cultivadas , Humanos , Leucemia Linfocítica Crônica de Células B/patologia , Células Estromais/metabolismo , Células Estromais/patologia
11.
World J Gastroenterol ; 16(19): 2407-10, 2010 May 21.
Artigo em Inglês | MEDLINE | ID: mdl-20480527

RESUMO

AIM: To investigate relapse predictors in chronic hepatitis C (CHC) patients with end-of-treatment response (ETR), after pegylated interferon-alpha (PegIFN-alpha) and ribavirin treatment. METHODS: In a retrospective study we evaluated a spectrum of predictors of relapse after PegIFN-alpha and ribavirin treatment in 86 CHC patients with ETR. Viral loads were determined with real-time reverse transcription polymerase chain reaction. Hepatitis C virus genotyping was performed by sequencing analysis. Patients with genotype 1 were treated for 48 wk with 180 microg PegIFN-alpha2a or 1.5 microg/kg PegIFN-alpha2b once weekly plus ribavirin at a dosage of 1000 mg/d for those under 75 kg or 1200 mg/d for those over 75 kg. Patients with genotypes 2 and 3 were treated for 24 wk with 180 microg PegIFN-alpha2a or 1.5 microg/kg PegIFN-alpha2b once weekly plus ribavirin at a dosage of 800 mg/d. RESULTS: In all ETR patients, binary logistic regression analysis identified absence of complete early virological response (cEVR) (OR 27.07, 95% CI: 3.09-237.26, P < 0.005), serum alkaline phosphatase (ALP) levels prior to therapy < 75 U/L (OR: 6.16, 95% CI: 2.1-18.03, P < 0.001) and body mass index > 26 kg/m(2) (OR: 8.27, 95% CI: 2.22-30.84, P < 0.005) as independent predictors of relapse. When cEVR patients were analyzed exclusively, ALP prior to therapy < 75 U/L remained the only predictor of relapse. CONCLUSION: Lower levels of ALP prior to, during and after therapy seem to be associated with a higher risk of relapse in CHC patients with ETR.


Assuntos
Fosfatase Alcalina/sangue , Antivirais/uso terapêutico , Hepatite C Crônica/tratamento farmacológico , Interferon-alfa/uso terapêutico , Polietilenoglicóis/uso terapêutico , Ribavirina/uso terapêutico , Adolescente , Adulto , Idoso , Biomarcadores/sangue , Quimioterapia Combinada , Feminino , Genótipo , Hepacivirus/genética , Hepatite C Crônica/diagnóstico , Hepatite C Crônica/enzimologia , Humanos , Interferon alfa-2 , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Razão de Chances , Valor Preditivo dos Testes , RNA Viral/sangue , Proteínas Recombinantes , Recidiva , Estudos Retrospectivos , Medição de Risco , Fatores de Risco , Fatores de Tempo , Resultado do Tratamento , Carga Viral , Adulto Jovem
13.
Crit Rev Oncol Hematol ; 76(2): 79-98, 2010 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-20185329

RESUMO

Neoplastic stem cells have initially been characterized in myeloid leukemias where NOD/SCID mouse-repopulating progenitors supposedly reside within a CD34+/Lin- subset of the malignant clone. These progenitors are considered to be self-renewing cells responsible for the in vivo long-term growth of neoplastic cells in leukemic patients. Therefore, these cells represent an attractive target of therapy. In some lymphoid leukemias, NOD/SCID mouse-repopulating cells were also reported to reside within the CD34+/Lin- subfraction of the clone. More recently, several attempts have been made to transfer the cancer stem cell concept to solid tumors and other non-hematopoietic neoplasms. In several of these tumors, the cell surface antigens AC133 (CD133) and CD44 are considered to indicate the potential of a cell to initiate permanent tumor formation in vivo. However, several questions concerning the phenotype, self-renewal capacity, stroma-dependence, and other properties of cancer- or leukemia-initiating cells remain to be solved. The current article provides a summary of our current knowledge on neoplastic (cancer) stem cells, with special emphasis on clinical implications and therapeutic options as well as a discussion about conceptual and technical limitations.


Assuntos
Neoplasias/patologia , Células-Tronco Neoplásicas/patologia , Animais , Humanos
14.
Br J Haematol ; 148(6): 868-78, 2010 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-19995395

RESUMO

One characteristic of chronic lymphocytic leukaemia (CLL) lymphocytes is high expression of CD23, which has previously been identified as a downstream target for NOTCH2 signalling. The mechanisms regulating NOTCH2-dependent CD23 expression, however, are largely unknown. This study showed that peripheral CLL cells overexpressed transcriptionally active NOTCH2 (N2(IC)), irrespective of their prognostic marker profile. When placed in culture, NOTCH2 activity was spontaneously decreased in 25 out of 31 CLL cases (81%) within 24 h. DNA-bound N2(IC) complexes could be maintained by the protein kinase C (PKC) activator phorbol 12-myristate 13-acetate (PMA) or by gamma-interferon (IFN-gamma), two CLL characteristic inducers of CD23 expression. Inhibition of PKC-delta by RNA interference or by rottlerin antagonised PMA-induced NOTCH2 activation and also suppressed NOTCH2 activity in CLL cases with constitutively activated NOTCH2 signalling. In 23 out of 29 CLL cases tested (79%), DNA-bound N2(IC) complexes were found to be resistant to the gamma-secretase inhibitor (GSI) DAPT, suggesting that GSIs will be only effective in a subset of CLL cases. These data suggest that deregulation of NOTCH2 signalling is critically involved in maintaining the malignant phenotype of CLL lymphocytes and point to a link between PKC-delta and NOTCH2 signalling in the leukemic cells.


Assuntos
Leucemia Linfocítica Crônica de Células B/imunologia , Proteínas de Neoplasias/metabolismo , Proteína Quinase C-delta/metabolismo , Receptor Notch2/metabolismo , Receptores de IgE/metabolismo , Antígenos de Neoplasias/metabolismo , Biomarcadores Tumorais/metabolismo , Humanos , Interferon gama/imunologia , Leucemia Linfocítica Crônica de Células B/genética , Prognóstico , Proteína Quinase C-delta/antagonistas & inibidores , Interferência de RNA , Receptor Notch2/genética , Transdução de Sinais , Acetato de Tetradecanoilforbol/imunologia , Células Tumorais Cultivadas
15.
Wien Klin Wochenschr ; 121(19-20): 631-7, 2009.
Artigo em Inglês | MEDLINE | ID: mdl-19921130

RESUMO

BACKGROUND: B-type natriuretic peptide (BNP) plays a key role in the regulation of volume homeostasis, and elevated blood levels of BNP are associated with end-stage renal disease. Renal transplantation leads to a decrease of elevated BNP levels with established graft function. Assessment of N-terminal pro-BNP (NT-proBNP) is established as reflecting volume homeostasis, and we therefore studied the relationship between NT-proBNP and allograft function in a prospective study. METHODS: NT-proBNP was assessed in 76 patients with end-stage renal disease undergoing renal transplantation. Patients were grouped according to immediate or delayed graft function. The degree of allograft function was assessed from the estimated glomerular filtration rate according to the MDRD formula. RESULTS: In patients with immediate graft function (n = 48), median NT-proBNP decreased immediately after transplantation; in patients with delayed function (n = 28), median NT-proBNP first increased and then decreased as function improved. Patients with early acute rejection showed significantly higher NT-proBNP levels prior to transplantation than patients without rejection. NT-proBNP levels measured 2 or 3 weeks post-transplant were significantly correlated with the estimated glomerular filtration rate 1 year after transplantation. CONCLUSIONS: An association was observed between renal allograft function and post-transplant levels of NT-proBNP. The association was not found to be a useful general predictor for graft function in individual patients in a clinical setting, as the range of NT-proBNP levels measured was too wide.


Assuntos
Rejeição de Enxerto/sangue , Rejeição de Enxerto/diagnóstico , Falência Renal Crônica/diagnóstico , Falência Renal Crônica/cirurgia , Transplante de Rim/efeitos adversos , Peptídeo Natriurético Encefálico/sangue , Avaliação de Resultados em Cuidados de Saúde/métodos , Fragmentos de Peptídeos/sangue , Adolescente , Adulto , Idoso , Feminino , Humanos , Falência Renal Crônica/sangue , Masculino , Pessoa de Meia-Idade , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Adulto Jovem
16.
Wien Klin Wochenschr ; 118(9-10): 266-72, 2006 May.
Artigo em Inglês | MEDLINE | ID: mdl-16810484

RESUMO

BACKGROUND: Ankylosing spondylitis (AS) is a chronic inflammatory disease of the axial joints with no satisfactory therapy. Reduction of joint pain has been reported after a course of therapy at a spa, Gasteiner Heilstollen, in Badgastein in Austria. The mechanism underlying this beneficial effect is not clearly understood and objective evidence for the biological response to therapy is lacking. The aim of this study was to find evidence for a biological response to speleotherapy in patients with AS and to study the involvement of the antiinflammatory cytokine TGF-beta1 in this response. PATIENTS AND METHODS: 83 patients with AS were treated in Badgastein for 3-4 weeks. Therapy included active exercises, hyperthermia and exposure to low doses of radon in a former mine. Response to therapy was assessed from measurement of morning pain and immunoassay of serum levels of TGF-beta1 before and after therapy. Ten AS patients who received conventional therapy and 10 patients with low back pain (LBP) served as controls. RESULTS: A significant increase in TGF-beta1 (total and active) was found in AS patients after spa therapy. Mean concentration of total TGF-beta1 increased from 28,715 pg/ml to 43,136 pg/ml, (P<0.01) and active TGF-beta1 increased from 77 pg/ml to 1096 pg/ml (P<0.001). When the AS patients were divided into two groups according to pain reduction, group 1 (decrease in morning pain, responders: n=46) exhibited a 17-fold increase of active TGF-beta1 levels (96 pg/ml to 1654 pg/ml, P<0.0001) whereas group 2 (no change or an increase in morning pain: nonresponders: n=37), showed only 7-fold increase (53 pg/ml to 402 pg/ml, P<0.01). There was a moderate increase in active TGF-beta1 from 31 pg/ml to 42 pg/ml (P<0.05) in patients with LBP and no significant change was observed in the patients treated with conventional therapy. CONCLUSION: These results demonstrate a significant increase in circulating TGF-beta1 in patients with AS after the combined spa-exercise therapy in Badgastein. The results also provide evidence for a biological response to speleotherapy and suggest that TGF-beta, through its antiinflammatory function, may play a role in this response.


Assuntos
Balneologia/métodos , Terapia por Exercício/métodos , Espondilite Anquilosante/sangue , Espondilite Anquilosante/terapia , Fator de Crescimento Transformador beta/sangue , Adulto , Idoso , Biomarcadores/sangue , Terapia Combinada , Feminino , Humanos , Fatores Imunológicos/sangue , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Fator de Crescimento Transformador beta1 , Resultado do Tratamento
17.
Clin Chem ; 52(1): 148-51, 2006 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-16391332

RESUMO

BACKGROUND: Hypolactasia and lactose intolerance are common conditions worldwide. Hypolactasia seems to be strongly correlated with genotype C/C of the genetic variant C-->T(-13910) upstream of the lactase phlorizin hydrolase (LPH) gene. We developed a rapid genotyping assay for LPH C-->T(-13910) and investigated the relationship of positive lactose breath hydrogen test (LBHT) results suggesting lactose intolerance with LPH C-->T(-13910) genotype. METHODS: Using automated DNA purification on the MagNA Pure LC and real-time PCR on the LightCycler, we examined samples from 220 individuals to estimate genotype frequencies; we then determined LPH C-->T(-13910) genotype in samples from 54 Caucasian patients with a positive LBHT result and symptoms of lactose intolerance. RESULTS: Genotyping of 220 individuals revealed frequencies of 21.4%, 41.8%, and 36.8% for genotypes C/C, C/T, and T/T. Of the patients with positive LBHT results, only 50% had the C/C genotype suggestive of primary adult hypolactasia in our study population. The other patients had various degrees of secondary hypolactasia or symptoms of lactose intolerance. Patients with C/C genotype had a mean (SD) peak H2 increase in the LBHT [108 (58) ppm] that was significantly higher than in patients with the C/T [65 (54) ppm] and T/T [44 (34) ppm] genotypes. CONCLUSIONS: The new real-time PCR assay provides a rapid, labor-saving means for the genotyping of LPH C-->T(-13910). Use of the assay may assist in differentiating patients with primary hypolactasia from those with secondary hypolactasia and lactose intolerance, who may need further clinical examinations to diagnose their underlying primary diseases.


Assuntos
Lactase-Florizina Hidrolase/genética , Intolerância à Lactose/diagnóstico , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Testes Respiratórios , Feminino , Genótipo , Humanos , Lactase-Florizina Hidrolase/análise , Intolerância à Lactose/enzimologia , Masculino , Pessoa de Meia-Idade , Reação em Cadeia da Polimerase , Polimorfismo Genético , Estudos Retrospectivos
18.
J Hepatol ; 44(2): 275-82, 2006 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-16338019

RESUMO

BACKGROUND/AIMS: Amantadine may augment virological response rates to interferon-based therapy in chronic hepatitis C patients. Using a novel design, amantadine was studied in naïve genotype 1 patients treated in combination with peginterferon alfa-2a (40KD)/ribavirin. METHODS: Patients enrolled in this randomized, placebo-controlled multicenter trial were stratified by single-dose interferon sensitivity (stratum I, 24-h HCV-RNA decline >1.4-log10; II, 0.8-1.39-log10; III, <0.8-log10; a reliable means of identifying nonresponders to interferon/ribavirin) and fibrosis grade (F0/1/2 vs. F3/4) at baseline. All patients received peginterferon alfa-2a (40KD) 180 microg/week plus ribavirin 1000-1200 mg/day and were randomized to receive amantadine 100 mg twice daily (N = 114) or placebo (N = 95) for 48 weeks. RESULTS: Week-24 virological response rates in strata II and III, the primary outcome, were similar in patients treated with amantadine (63.7%) or placebo (65.7%), as were sustained virological response rates at week 72 (46.5 and 51.6%, respectively). Adverse event profiles were similar and amantadine did not improve health-related quality of life compared with placebo. Interferon sensitivity was the only significant predictor of treatment outcome. CONCLUSIONS: Adding amantadine to peginterferon alfa-2a (40KD)/ribavirin combination therapy does not augment virological response rates in genotype 1 patients. Virological response was almost exclusively determined by interferon sensitivity at baseline.


Assuntos
Amantadina/uso terapêutico , Antivirais/uso terapêutico , Hepacivirus/genética , Hepatite C Crônica/tratamento farmacológico , Interferon-alfa/uso terapêutico , Polietilenoglicóis/uso terapêutico , RNA Viral/genética , Ribavirina/uso terapêutico , Adulto , Progressão da Doença , Método Duplo-Cego , Portadores de Fármacos , Quimioterapia Combinada , Feminino , Seguimentos , Genótipo , Hepacivirus/isolamento & purificação , Hepatite C Crônica/patologia , Hepatite C Crônica/virologia , Humanos , Interferon alfa-2 , Masculino , Pessoa de Meia-Idade , Qualidade de Vida , Proteínas Recombinantes , Resultado do Tratamento
19.
J Clin Invest ; 113(5): 676-85, 2004 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-14991065

RESUMO

The mechanisms that lead to reticulin fibrosis of bone marrow (BM) in hairy cell leukemia (HCL) are not fully understood. We therefore investigated the involvement of TGF-beta1, a potent fibrogenic cytokine, in this process. Immunoassays revealed that TGF-beta1 is present at higher concentrations in BM, serum, and plasma of HCL patients in comparison with healthy donors (P < 0.001). RT-PCR and immunofluorescence studies showed that TGF-beta1 is overexpressed at the mRNA and protein levels in peripheral blood, spleen, and BM mononuclear cells and that hairy cells (HCs) are the main source of TGF-beta1. Active TGF-beta1 correlated significantly with grades of BM fibrosis, infiltration with HCs, and serum procollagen type III aminoterminal propeptide (PIIINP). Ex vivo studies demonstrated that TGF-beta1 significantly enhances the production and deposition of reticulin and collagen fibers by BM fibroblasts. In addition, BM plasma of HCL patients increased the synthesis of type I and type III procollagens, the main components of reticulin fibers, at the mRNA and protein levels. This fibrogenic activity of BM plasma was abolished by neutralizing anti-TGF-beta1 antibodies. These results show, for the first time to our knowledge, that TGF-beta1 is highly expressed in HCs and is directly involved in the pathogenesis of BM reticulin fibrosis in HCL.


Assuntos
Medula Óssea/metabolismo , Leucemia de Células Pilosas/metabolismo , Mielofibrose Primária/patologia , Reticulina/metabolismo , Fator de Crescimento Transformador beta/fisiologia , Idoso , Idoso de 80 Anos ou mais , Células da Medula Óssea , Células Cultivadas , Colágeno/metabolismo , Colágeno Tipo III/química , Ensaio de Imunoadsorção Enzimática , Feminino , Fibroblastos/metabolismo , Fibrose , Técnica Indireta de Fluorescência para Anticorpo , Humanos , Imunoensaio , Leucócitos Mononucleares/metabolismo , Masculino , Microscopia de Fluorescência , Pessoa de Meia-Idade , Peptídeos/química , RNA Mensageiro/metabolismo , Radioimunoensaio , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Fatores de Tempo , Fator de Crescimento Transformador beta/metabolismo , Fator de Crescimento Transformador beta1
20.
Ren Fail ; 24(2): 197-205, 2002 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-12071593

RESUMO

Despite improvements in dialysis therapy, the mortality rate of patients with end stage renal disease (ESRD) has remained high. A relatively high proportion of uremic patients dies within one year after the initiation of dialysis treatment. The aim of this study was to evaluate predictors for this early mortality in patients with ESRD. A total of 66 uremic patients were included in the study. Patients were divided in those who survived < 1 year (n = 17) and those who survived > or = 1 year (n = 49). We compared the prevalence of diabetes and hypertension and of vascular diseases as well as the prevalence of heart insufficiency (EF < 30%) and left ventricular hypertrophy (LVH). Additionally, we estimated the laboratory parameters serum creatinine, creatinine clearance, BUN, cholesterol, triglycerides, fibrinogen, serum protein, serum albumin and hemoglobin, and evaluated the indications for the initiation of dialysis therapy in both patient groups. The patients with survival < 1 year were significantly older (64+/-12 vs. 54+/-14 years, p<0.01) and showed a lower BMI (22+/-3 vs. 25+/-3, p<0.01) than those who survived > 1 year. The prevalence of diabetes (70% vs. 31%, p<0.05), cardiac insufficiency (70% vs. 16%, p<0.025), cardiovascular disease (65% vs. 28%, p<0.05) and peripheral vascular diseases (70% vs. 28%, p<0.05) was significantly higher in the patients with early mortality. The prevalence of hypertension was similar in both groups, however, the prevalence of LVH was significantly higher in the patients who survived < 1 year (88% vs. 37%, p<0.05). Laboratory parameters were not significantly different in the two groups of patients, with the exception of serum albumin, which was significantly lower in the patients with early mortality (3.5+/-0.6 vs. 3.9+/-0.4 g/l, p<0.02). Hyperhydration was the most common indication for the start of dialysis in patients with early mortality (59% vs. 13%, p<0.025). Cardiac insufficiency was the most common cause of death in these subjects (n = 10, 59%). Six individuals (12%) died within four weeks after initiating dialysis therapy. Thus, there are several predictors for early mortality in end-stage renal disease patients, including high age, low BMI, the presence of diabetes, coronary heart disease, heart insufficiency and LVH, as well as low serum albumin levels. A relatively high percentage of patients die shortly after the start of dialysis therapy. Heart insufficiency is the most common cause of early death in these patients.


Assuntos
Falência Renal Crônica/mortalidade , Falência Renal Crônica/terapia , Diálise Renal , Uremia/mortalidade , Uremia/terapia , Adulto , Fatores Etários , Idoso , Índice de Massa Corporal , Feminino , Humanos , Falência Renal Crônica/complicações , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Estudos Retrospectivos , Fatores de Risco , Taxa de Sobrevida , Fatores de Tempo , Uremia/etiologia
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