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MP0250 is a designed ankyrin repeat protein that specifically inhibits both vascular endothelial growth factor A (VEGF-A) and hepatocyte growth factor (HGF), aiming at potentiating cancer therapy by disrupting the tumour microenvironment. Encouraging results from a phase 1 trial of MP0250 in patients with solid tumours prompted further investigation in multiple myeloma (MM) as both MP0250 targets are reported to be drivers of MM pathogenesis. In this open-label, single-arm phase 1b/2 study (NCT03136653) in patients with proteasome inhibitor- and/or immunomodulatory drug-relapsed or refractory MM, MP0250 was administered every 3 weeks with standard bortezomib/dexamethasone regimen. Thirty-three patients received at least one dose of MP0250. The most frequent treatment-related adverse events were arterial hypertension (58.1%), thrombocytopenia (32.3%), proteinuria (29.0%) and peripheral oedema (19.4%). Of the 28 patients evaluable for response (median age: 60 [range 44-75]), nine achieved at least partial response, corresponding to an overall response rate of 32.1% (95% confidence interval [CI]: 17.9%, 50.7%), with a median duration of response of 8 months (95% CI 5-NR). An additional three patients achieved minimal response and nine stable diseases as the best overall response. Overall median progression-free survival was 4.2 months (95% CI 1.9-7.1). These findings are in line with the results of recent trials testing new agents on comparable patient cohorts and provide initial evidence of clinical benefit for patients with refractory/relapsed MM treated with MP0250 in combination with bortezomib/dexamethasone. Further clinical evaluation in the emerging MM treatment landscape would be required to confirm the clinical potential of MP0250.
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BACKGROUND: International oncology societies recommend early palliative care. Specific models to integrate early palliative care efficiently into clinical practice are debated. The authors designed a study to look at the quantitative and qualitative outcomes of an early palliative care intervention in oncological care to decrease stress and improve quality of life. AIMS: To compare a single structured early palliative care intervention added to a usual oncology care in terms of distress and health-related quality of life at baseline compared to 6 months after enrollment. DESIGN: This multicenter randomized controlled trial (NCT01983956) enrolled adult patients with advanced cancer. Participants were either randomly assigned to usual oncology care alone or usual care plus a structured early palliative care intervention. SETTING/PARTICIPANTS: One hundred fifty adult patients with a variety of advanced cancer diagnoses were randomized. Seventy-four participants were in the intervention and 76 participants in the control group. The primary outcome was the change in patient distress assessed by the National Comprehensive Cancer Network distress thermometer at 6 months. Health-related quality of life, the secondary outcome, was assessed by the Functional Assessment of Cancer Therapy-General Questionnaire. RESULTS: The results showed no significant effect of the early palliative care intervention neither on patient distress nor on health-related quality of life. CONCLUSION: The addition of an early intervention to usual care for patients with advanced cancer did not improve distress or quality of life. Thus, patients may need more intensive early palliative care with continuous professional support to identify and address their palliative needs early.
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Enfermagem de Cuidados Paliativos na Terminalidade da Vida , Neoplasias , Adulto , Humanos , Neoplasias/terapia , Cuidados Paliativos , Qualidade de VidaRESUMO
OBJECTIVES: Src tyrosine kinase inhibitors (TKIs) significantly inhibit cell migration and invasion in lung cancer cell lines with minor cytotoxic effects. In clinical trials, however, they show modest activity in combination with chemotherapeutic agents. Possible resistance mechanisms include the induction of cytoprotective autophagy upon Src inhibition. Autophagy is a cellular recycling process that allows cell survival in response to a variety of stress stimuli including responses to various treatments. MATERIAL AND METHODS: We screened autophagic activity in A549, H460, and H1299 NSCLC cell lines treated with two different Src-TKIs (saracatinib, dasatinib) or shRNA targeting SRC. The autophagy response was determined by LC3B-I to -II conversion, increased ULK1 epxression and increased GFP-LC3B dot formation. Autophagy was inhibited by pharmacological (bafilomycin A, chloroquine) or genetic (ULK1 shRNA) means. Expression of miR-106a and miR-20b was analyzed by qPCR, and we used different lentivral vectors for ectopic expression of either miR-106a mimetics, anti-sense miR-106a or different miR-106a-363 cluster constructs. RESULTS: In the current study we found that Src-TKIs induce autophagy in lung adenocarcinoma cell lines and that a combination of autophagy and Src tyrosine kinase inhibition results in cell death. Moreover, Src-TKI induced autophagy depends on the induction of the key autophagy kinase ULK1. This ULK1 upregulation is caused by downregulation of the ULK1-targeting microRNA-106a. An inverse correlation of miR-106a and ULK1 expression was seen in lung adenocarcinoma. Accordingly, ectopic expression of miR-106a in combination with Src-TKI treatment resulted in significant cell death as compared to control transduced cells. CONCLUSIONS: Autophagy protects lung adenocarcinoma cells from Src-TKIs via a newly identified miR-106a-ULK1 signaling pathway. The combined inhibition of Src and ULK1/autophagy might represent a promising treatment option for future clinical trials. Lastly, our data might challenge the term "oncogenic" miR-106a as it can promote sensitivity to Src-TKIs thereby underlining the context-dependent function of miRNAs.
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Adenocarcinoma/patologia , Autofagia/efeitos dos fármacos , Carcinoma Pulmonar de Células não Pequenas/patologia , Neoplasias Pulmonares/patologia , Pulmão/patologia , MicroRNAs/genética , Inibidores de Proteínas Quinases/farmacologia , Quinases da Família src/antagonistas & inibidores , Adenocarcinoma/tratamento farmacológico , Adenocarcinoma/genética , Adenocarcinoma de Pulmão , Proteína Homóloga à Proteína-1 Relacionada à Autofagia/genética , Benzodioxóis/farmacologia , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Carcinoma Pulmonar de Células não Pequenas/genética , Movimento Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Dasatinibe/farmacologia , Regulação para Baixo/efeitos dos fármacos , Humanos , Peptídeos e Proteínas de Sinalização Intracelular/genética , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/genética , Proteínas Associadas aos Microtúbulos , Quinazolinas/farmacologia , RNA Interferente Pequeno , Transdução de Sinais/efeitos dos fármacos , Quinases da Família src/metabolismo , Quinases da Família src/farmacologiaRESUMO
The European Society for Medical Oncology (ESMO) and the American Society of Clinical Oncology (ASCO) are publishing a new edition of the ESMO/ASCO Global Curriculum (GC) thanks to contribution of 64 ESMO-appointed and 32 ASCO-appointed authors. First published in 2004 and updated in 2010, the GC edition 2016 answers to the need for updated recommendations for the training of physicians in medical oncology by defining the standard to be fulfilled to qualify as medical oncologists. At times of internationalisation of healthcare and increased mobility of patients and physicians, the GC aims to provide state-of-the-art cancer care to all patients wherever they live. Recent progress in the field of cancer research has indeed resulted in diagnostic and therapeutic innovations such as targeted therapies as a standard therapeutic approach or personalised cancer medicine apart from the revival of immunotherapy, requiring specialised training for medical oncology trainees. Thus, several new chapters on technical contents such as molecular pathology, translational research or molecular imaging and on conceptual attitudes towards human principles like genetic counselling or survivorship have been integrated in the GC. The GC edition 2016 consists of 12 sections with 17 subsections, 44 chapters and 35 subchapters, respectively. Besides renewal in its contents, the GC underwent a principal formal change taking into consideration modern didactic principles. It is presented in a template-based format that subcategorises the detailed outcome requirements into learning objectives, awareness, knowledge and skills. Consecutive steps will be those of harmonising and implementing teaching and assessment strategies.
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The RNA binding proteins RBM binding motif protein 38 (RBM38) and DEAD END 1 (DND1) selectively stabilize mRNAs by attenuating RNAse activity or protecting them from micro(mi)RNA-mediated cleavage. Furthermore, both proteins can efficiently stabilize the mRNA of the cell cycle inhibitor p21(CIP1). Since acute myeloid leukemia (AML) differentiation requires cell cycle arrest and RBM38 as well as DND1 have antiproliferative functions, we hypothesized that decreased RBM38 and DND1 expression may contribute to the differentiation block seen in this disease. We first quantified RBM38 and DND1 mRNA expression in clinical AML patient samples and CD34(+) progenitor cells and mature granulocytes from healthy donors. We found significantly lower RBM38 and DND1 mRNA levels in AML blasts and CD34(+) progenitor cells as compared to mature neutrophils from healthy donors. Furthermore, the lowest expression of both RBM38 and DND1 mRNA correlated with t(8;21). In addition, neutrophil differentiation of CD34(+) cells in vitro with G-CSF (granulocyte colony stimulating factor) resulted in a significant increase of RBM38 and DND1 mRNA levels. Similarly, neutrophil differentiation of NB4 acute promyelocytic leukemia (APL) cells was associated with a significant induction of RBM38 and DND1 expression. To address the function of RBM38 and DND1 in neutrophil differentiation, we generated two independent NB4RBM38 as well as DND1 knockdown cell lines. Inhibition of both RBM38 and DND1 mRNA significantly attenuated NB4 differentiation and resulted in decreased p21(CIP1) mRNA expression. Our results clearly indicate that expression of the RNA binding proteins RBM38 and DND1 is repressed in primary AML patients, that neutrophil differentiation is dependent on increased expression of both proteins, and that these proteins have a critical role in regulating p21(CIP1) expression during APL differentiation.
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Regulação Leucêmica da Expressão Gênica/fisiologia , Leucemia Mieloide Aguda/patologia , Leucemia Promielocítica Aguda/patologia , Proteínas de Neoplasias/biossíntese , Neutrófilos/patologia , Proteínas de Ligação a RNA/biossíntese , Adolescente , Adulto , Idoso , Western Blotting , Diferenciação Celular , Feminino , Técnicas de Silenciamento de Genes , Humanos , Masculino , Pessoa de Meia-Idade , Reação em Cadeia da Polimerase em Tempo Real , Adulto JovemRESUMO
Successful myeloid differentiation depends on the expression of a series of miRNAs. Thus, it is hardly surprising that miRNAs are globally repressed in AML, a disease mainly characterized by a block in cellular myeloid differentiation. Studies investigating the mechanisms for low miRNA expression in AML has mostly focused on altered transcriptional regulation or deletions, whereas defective miRNA processing has received less attention. In this study, we report that the expression of the key miRNA processing enzyme DICER1 is down-regulated in primary AML patient samples and healthy CD34(+) progenitor cells as compared with granulocytes. In line with these findings, Dicer1 expression was induced significantly in AML cell lines upon neutrophil differentiation. The knocking down of DICER1 in AML cells significantly attenuated neutrophil differentiation, which was paralleled by decreased expression of miRNAs involved in this process. Moreover, we found that inhibiting DICER1 attenuated the activation of autophagy, a cellular recycling process that is needed for proper neutrophil differentiation of AML cells. Our results clearly indicate that DICER1 plays a novel role in neutrophil differentiation as well as in myeloid autophagy of AML cells.
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Autofagia , Diferenciação Celular , RNA Helicases DEAD-box/metabolismo , Neutrófilos/citologia , Ribonuclease III/metabolismo , Autofagia/efeitos dos fármacos , Diferenciação Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Técnicas de Silenciamento de Genes , Humanos , Leucemia Promielocítica Aguda/metabolismo , Leucemia Promielocítica Aguda/patologia , MicroRNAs/metabolismo , Neutrófilos/efeitos dos fármacos , Neutrófilos/metabolismo , Processamento Pós-Transcricional do RNA/efeitos dos fármacos , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Tretinoína/farmacologiaRESUMO
In an mRNA profiling screen performed to unveil novel mechanisms of leukemogenesis, we found that the sentrin-specific protease 5 (SENP5) was significantly repressed in clinical acute myeloid leukemia when compared to healthy neutrophil samples. SENP5 is an enzyme that targets and cleaves small ubiquitin-like modifier (SUMO) residues from SUMOylated proteins. Further investigation with AML neutrophil differentiation cell models showed increased SENP5 expression upon induction of differentiation; in contrast, knocking down SENP5 resulted in significantly attenuated neutrophil differentiation. Our results support a new role of SENP5 in AML pathology, and in particular in the neutrophil differentiation of myeloid leukemic cells.
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Modern oncology has much to offer, and the prognosis of cancer patients has undoubtedly improved over the last few decades. Nevertheless, medical and economic toxicities of modern cancer medicine demand that our many tools are viewed with a critical eye. Screening mammography and PSA screening for the detection of early breast, or prostate cancer, resp., are widely used. However, reduction of mortality from these disorders through early detection and treatment is quantitatively modest, whereas overdiagnosis of low-risk cancers and non-malignant conditions with these two methods is frequent. Cancer drug therapy increasingly uses predictive bio-markers to select patients (and their tumors) particularly likely to benefit from new drugs. Nevertheless palliative systemic treatment in oncology suffers from over-use of drugs with at times considerable toxicity and cost but little patient gain. It is still common practice to validate new cancer drugs in clinical trials using progression-free survival as a primary endpoint. PFS is easily measurable but often inadequate to discover true clinical benefit (i. e. prolonged overall survival and/or improved lasting quality of life). Licensing agencies such as the FDA or Swissmedic as well as clinical trialists are therefore challenged to review their criteria for the validation of new cancer drugs. Follow-up of cancer patients after treatment is widely practiced, often with "subscription series" for CT- or PET-scans and repetitive lab tests including tumor markers. Early detection of asymptomatic cancer relapse with these methods, however, is only warranted, if early re-treatment is proven to prolong survival, as cancer treatment in asymptomatic patients produces toxicity and costs that can only be justified if chances for long-term benefits are bettered.
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Antineoplásicos/uso terapêutico , Detecção Precoce de Câncer/métodos , Neoplasias/diagnóstico , Neoplasias/tratamento farmacológico , Seleção de Pacientes , Procedimentos Desnecessários , Antineoplásicos/efeitos adversos , Medicina Baseada em Evidências , Humanos , Neoplasias/prevenção & controle , Prevenção Primária/métodos , Prognóstico , Medição de Risco/métodos , Resultado do TratamentoRESUMO
The PU.1 transcription factor is essential for myeloid development. We investigated if the microtubule-associated protein 1S (MAP1S) is a novel PU.1 target with a link to autophagy, a cellular recycling pathway. Comparable to PU.1, MAP1S expression was significantly repressed in primary AML blasts as compared to mature neutrophils. Accordingly, MAP1S expression was induced during neutrophil differentiation of CD34(+) progenitor and APL cells. Moreover, PU.1 bound to the MAP1S promoter and induced MAP1S expression during APL differentiation. Inhibiting MAP1S resulted in aberrant neutrophil differentiation and autophagy. Taken together, our findings implicate the PU.1-regulated MAP1S gene in neutrophil differentiation and autophagy control.
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Autofagia/genética , Diferenciação Celular/genética , Leucemia Promielocítica Aguda/genética , Proteínas Associadas aos Microtúbulos/genética , Proteínas Proto-Oncogênicas/fisiologia , Transativadores/fisiologia , Células Cultivadas , Feminino , Regulação Leucêmica da Expressão Gênica , Humanos , Recém-Nascido , Leucemia Promielocítica Aguda/patologia , Leucemia Promielocítica Aguda/fisiopatologia , Cultura Primária de Células , Regulação para Cima/genéticaRESUMO
The basic leucine zipper transcription factor CCAAT/enhancer binding protein alpha (CEBPA) codes for a critical regulator during neutrophil differentiation. Aberrant expression or function of this protein contributes to the development of acute myeloid leukemia (AML). In this study, we identified two novel unrelated CEBPA target genes, the glycolytic enzyme hexokinase 3 (HK3) and the krüppel-like factor 5 (KLF5) transcription factor, by comparing gene profiles in two cohorts of CEBPA wild-type and mutant AML patients. In addition, we found CEBPA-dependent activation of HK3 and KLF5 transcription during all-trans retinoic acid (ATRA) mediated neutrophil differentiation of acute promyelocytic leukemia (APL) cells. Moreover, we observed direct regulation of HK3 by CEBPA, whereas our data suggest an indirect regulation of KLF5 by this transcription factor. Altogether, our data provide an explanation for low HK3 and KLF5 expression in particular AML subtype and establish these genes as novel CEBPA targets during neutrophil differentiation.
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Proteínas Estimuladoras de Ligação a CCAAT/metabolismo , Hexoquinase/metabolismo , Fatores de Transcrição Kruppel-Like/metabolismo , Leucemia Mieloide Aguda/metabolismo , Leucemia Mieloide Aguda/patologia , Neutrófilos/metabolismo , Neutrófilos/patologia , Diferenciação Celular , Linhagem Celular Tumoral , Transformação Celular Neoplásica/metabolismo , Transformação Celular Neoplásica/patologia , HumanosRESUMO
AIMS: ID1 is an important component of the MET-SRC signaling pathway, which is a regulator of cell migration and invasion. We hypothesized that the ALK/MET inhibitor crizotinib inhibits migration via MET-SRC-ID1, rather than ALK. MATERIALS & METHODS: We used ALK fusion-positive and -negative lung cancer cell lines; crizotinib, PHA-665752, and saracatinib, and stable transfection with shMET. We performed western blotting for p-ALK, ALK, p-MET, MET, p-SRC, SRC and ID1, and quantitative real-time PCR for ID1. RESULTS: Crizotinib decreased p-MET, p-SRC and ID1 levels in ALK- and or MET-positive cell lines and inhibited cell migration. Knockdown of MET was comparable with the effect of crizotinib. CONCLUSION: The effects of crizotinib on ID1 expression and cancer cell migration were associated with the presence of activated MET, rather than ALK fusion.
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Antineoplásicos/farmacologia , Movimento Celular/efeitos dos fármacos , Proteína 1 Inibidora de Diferenciação/metabolismo , Neoplasias Pulmonares/metabolismo , Inibidores de Proteínas Quinases/farmacologia , Proteínas Proto-Oncogênicas c-met/metabolismo , Pirazóis/farmacologia , Piridinas/farmacologia , Linhagem Celular Tumoral , Crizotinibe , Humanos , Proteína 1 Inibidora de Diferenciação/genética , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/genética , Terapia de Alvo Molecular , Proteínas de Fusão Oncogênica/genética , Proteínas de Fusão Oncogênica/metabolismo , Proteínas Proto-Oncogênicas c-met/genéticaRESUMO
DAPK2 is a proapoptotic protein that is mostly expressed in the hematopoietic tissue. A detailed DAPK2 expression analysis in two large AML patient cohorts revealed particularly low DAPK2 mRNA levels in APL. DAPK2 levels were restored in APL patients undergoing ATRA therapy. PML-RARA is the predominant lesion in APL causing transcriptional repression of genes important for neutrophil differentiation. We found binding of PML-RARA and PU.1, a myeloid master regulator, to RARA and PU.1 binding sites in the DAPK2 promoter. Ectopic expression of PML-RARA in non-APL, as well as knocking down PU.1 in APL cells, resulted in a significant reduction of DAPK2 expression. Restoring DAPK2 expression in PU.1 knockdown APL cells partially rescued neutrophil differentiation, thereby identifying DAPK2 as a relevant PU.1 downstream effector. Moreover, low DAPK2 expression is also associated with C/EBPα-mutated AML patients, and we found C/EBPα-dependent regulation of DAPK2 during APL differentiation. In conclusion, we identified first inhibitory mechanisms responsible for the low DAPK2 expression in particular AML subtypes, and the regulation of DAPK2 by two myeloid transcription factors underlines its importance in neutrophil development.
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Proteína alfa Estimuladora de Ligação a CCAAT/metabolismo , Diferenciação Celular/genética , Proteínas Quinases Associadas com Morte Celular/genética , Regulação da Expressão Gênica , Granulócitos/citologia , Granulócitos/metabolismo , Proteínas de Fusão Oncogênica/metabolismo , Proteínas Proto-Oncogênicas/metabolismo , Transativadores/metabolismo , Linhagem Celular Tumoral , Proteínas Quinases Associadas com Morte Celular/metabolismo , Humanos , Leucemia Mieloide Aguda/genética , Leucemia Mieloide Aguda/metabolismo , Leucemia Promielocítica Aguda/genética , Leucemia Promielocítica Aguda/metabolismo , Neutrófilos/citologia , Neutrófilos/metabolismo , Transcrição GênicaRESUMO
Autophagy is an intracellular bulk degradation process involved in cell survival upon stress induction, but also with a newly identified function in myeloid differentiation. The autophagy-related (ATG)8 protein family, including the GABARAP and LC3 subfamilies, is crucial for autophagosome biogenesis. In order to evaluate the significance of the GABARAPs in the pathogenesis of acute myeloid leukemia (AML), we compared their expression in primary AML patient samples, CD34(+) progenitor cells and in granulocytes from healthy donors. GABARAPL1 and GABARAPL2/GATE-16, but not GABARAP, were significantly downregulated in particular AML subtypes compared to normal granulocytes. Moreover, the expression of GABARAPL1 and GATE-16 was significantly induced during ATRA-induced neutrophil differentiation of acute promyelocytic leukemia cells (APL). Lastly, knocking down GABARAPL2/GATE-16 in APL cells attenuated neutrophil differentiation and decreased autophagic flux. In conclusion, low GABARAPL2/GATE-16 expression is associated with an immature myeloid leukemic phenotype and these proteins are necessary for neutrophil differentiation of APL cells.
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Proteínas Adaptadoras de Transdução de Sinal/antagonistas & inibidores , Autofagia , Regulação Leucêmica da Expressão Gênica , Leucemia Promielocítica Aguda/metabolismo , Proteínas dos Microfilamentos/antagonistas & inibidores , Neutrófilos/citologia , Tretinoína/metabolismo , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Adolescente , Adulto , Idoso , Antígenos CD34/metabolismo , Proteínas Reguladoras de Apoptose , Família da Proteína 8 Relacionada à Autofagia , Diferenciação Celular , Linhagem Celular , Feminino , Humanos , Leucemia Promielocítica Aguda/genética , Masculino , Proteínas dos Microfilamentos/metabolismo , Proteínas Associadas aos Microtúbulos/metabolismo , Pessoa de Meia-Idade , Adulto JovemRESUMO
MET, also known as hepatocyte growth factor receptor (HGFR), is a receptor tyrosine kinase with an important role, both in normal cellular function as well as in oncogenesis. In many cancer types, abnormal activation of MET is related to poor prognosis and various strategies to inhibit its function, including small molecule inhibitors, are currently in preclinical and clinical evaluation. Autophagy, a self-digesting recycling mechanism with cytoprotective functions, is induced by cellular stress. This process is also induced upon cytotoxic drug treatment of cancer cells and partially allows these cells to escape cell death. Thus, since autophagy protects different tumor cells from chemotherapy-induced cell death, current clinical trials aim at combining autophagy inhibitors with different cancer treatments. We found that in a gastric adenocarcinoma cell line GTL-16, where MET activity is deregulated due to receptor overexpression, two different MET inhibitors PHA665752 and EMD1214063 lead to cell death paralleled by the induction of autophagy. A combined treatment of MET inhibitors together with the autophagy inhibitor 3-MA or genetically impairing autophagy by knocking down the key autophagy gene ATG7 further decreased cell viability of gastric cancer cells. In general, we observed the induction of cytoprotective autophagy in MET expressing cells upon MET inhibition and a combination of MET and autophagy inhibition resulted in significantly decreased cell viability in gastric cancer cells.
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Adenocarcinoma/enzimologia , Autofagia/efeitos dos fármacos , Resistencia a Medicamentos Antineoplásicos , Inibidores de Proteínas Quinases/farmacologia , Proteínas Proto-Oncogênicas c-met/antagonistas & inibidores , Neoplasias Gástricas/enzimologia , Adenina/análogos & derivados , Adenina/farmacologia , Autofagia/genética , Proteína 7 Relacionada à Autofagia , Linhagem Celular Tumoral , Sobrevivência Celular , Técnicas de Silenciamento de Genes , Humanos , Indóis/farmacologia , Piridazinas/farmacologia , Pirimidinas/farmacologia , Sulfonas/farmacologia , Enzimas Ativadoras de Ubiquitina/genéticaAssuntos
Proteínas Estimuladoras de Ligação a CCAAT/genética , Regulação Leucêmica da Expressão Gênica , Leucemia Mieloide Aguda/genética , Leucemia Promielocítica Aguda/genética , Proteínas dos Microfilamentos/genética , Proteínas Proto-Oncogênicas/genética , Transativadores/genética , Proteínas Estimuladoras de Ligação a CCAAT/biossíntese , Proteínas Estimuladoras de Ligação a CCAAT/metabolismo , Humanos , Leucemia Mieloide Aguda/metabolismo , Leucemia Promielocítica Aguda/metabolismo , Proteínas dos Microfilamentos/biossíntese , Proteínas dos Microfilamentos/metabolismo , Proteínas Proto-Oncogênicas/metabolismo , Transativadores/metabolismo , Transcrição GênicaRESUMO
BACKGROUND: Inhibitors of apoptosis (IAPs) were intensively investigated in the context of cancer where they promote tumor growth and chemoresistence. Overexpression of the IAP BIRC6 is associated with unfavorable clinical features and negatively impacts relapse-free survival in childhood acute myeloid leukemia (AML). Currently, BIRC6 levels in adult primary AML have not been compared to the expression in normal myeloid cells. Thus, we compared for the first time BIRC6 levels in adult primary AML patient samples to normal myeloid cells and studied its regulation and function during neutrophil differentiation. FINDINGS: We found significantly lower BIRC6 levels in particular AML subtypes as compared to granulocytes from healthy donors. The lowest BIRC6 expression was found in CD34+ progenitor cells. Moreover, BIRC6 expression significantly increased during neutrophil differentiation of AML cell lines and knocking down BIRC6 in NB4 acute promyelocytic leukemia (APL) cells significantly impaired neutrophil differentiation, but not cell viability. CONCLUSION: Together, we found an association of low BIRC6 levels with an immature myeloid phenotype and describe a function for BIRC6 in neutrophil differentiation of APL cells.
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The damage-regulator autophagy modulator 1 (DRAM-1) is a lysosomal protein that positively regulates autophagy in a p53-dependent manner. We aimed at analyzing the role of DRAM-1 in granulocytic differentiation of APL cells. We observed a significant increase of DRAM-1 expression during all-trans retinoic acid (ATRA)-induced neutrophil differentiation of NB4 APL cells but not in ATRA-resistant NB4-R2 cells. Next, knocking down DRAM-1 in NB4 APL cells was sufficient to impair neutrophil differentiation. Given that DRAM-1 is a transcriptional target of p53, we tested if DRAM-1 is regulated by the p53 relative p73. Indeed, inhibiting p73 prevented neutrophil differentiation and DRAM-1 induction of NB4 cells. In conclusion, we show for the first time that p73-regulated DRAM-1 is functionally involved in neutrophil differentiation of APL cells.
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Proteínas de Ligação a DNA/genética , Leucemia Promielocítica Aguda/patologia , Neutrófilos/metabolismo , Proteínas Nucleares/genética , Proteínas/genética , Proteínas Supressoras de Tumor/genética , Autofagia , Diferenciação Celular , Linhagem Celular Tumoral , Proteínas de Ligação a DNA/antagonistas & inibidores , Proteínas de Ligação a DNA/metabolismo , Resistencia a Medicamentos Antineoplásicos , Regulação Neoplásica da Expressão Gênica , Inativação Gênica , Granulócitos/patologia , Humanos , Proteínas de Membrana , Neutrófilos/efeitos dos fármacos , Neutrófilos/patologia , Proteínas Nucleares/antagonistas & inibidores , Proteínas Nucleares/metabolismo , Isoformas de Proteínas/antagonistas & inibidores , Isoformas de Proteínas/genética , Isoformas de Proteínas/metabolismo , Proteínas/antagonistas & inibidores , Proteínas/metabolismo , RNA Interferente Pequeno/genética , Transdução de Sinais , Tretinoína/farmacologia , Proteína Tumoral p73 , Proteínas Supressoras de Tumor/antagonistas & inibidores , Proteínas Supressoras de Tumor/metabolismoRESUMO
INTRODUCTION: MicroRNAs are small, noncoding RNAs that suppress gene expression by binding to the 3' untranslated region (UTR) and thereby repress translation or decrease messenger RNA stability. Inhibitor of differentiation 1 (ID1) is a putative stem-cell gene involved in invasion and angiogenesis. We previously showed that ID1 is regulated by Src kinases, overexpressed in human lung adenocarcinoma, and targeted by Src-dependent microRNAs. The current study focused on the association between miR-381 and ID1 in lung adenocarcinoma. METHODS: An ID1 3'UTR-luciferase reporter assay was used to determine whether miR-381 directly targets ID1. Human lung cancer cell lines were stably transduced with a precursor of miR-381 to evaluate its role on ID1 expression and to investigate changes in cell migration and invasion. The Src tyrosine kinase inhibitors saracatinib and dasatinib were used to repress ID1 expression. MiR-381 expression was measured in 18 human lung adenocarcinomas and corresponding normal lung tissue by quantitative reverse-transcription polymerase chain reaction. RESULTS: ID1 is a direct target of miR-381 as shown by 3'UTR luciferase reporter assays. MiR-381 expression was negatively correlated with ID1 expression in lung cancer cell lines. Ectopic expression of miR-381 reduced ID1 mRNA and protein levels, and significantly decreased cell migration and invasion. Furthermore, miR-381 was significantly downregulated in human lung adenocarcinomas, and low miR-381 expression levels correlated with poor prognosis. CONCLUSION: These results suggest that downregulation of miR-381 and thus induction of its target ID1 may contribute to the metastatic potential of lung adenocarcinomas. Further studies to explore potential therapeutic strategies, including Src inhibitors, are ongoing.