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1.
J Cell Sci ; 129(20): 3756-3769, 2016 10 15.
Artigo em Inglês | MEDLINE | ID: mdl-27591259

RESUMO

Coordination between membrane trafficking and actin polymerization is fundamental in cell migration, but a dynamic view of the underlying molecular mechanisms is still missing. The Rac1 GTPase controls actin polymerization at protrusions by interacting with its effector, the Wave regulatory complex (WRC). The exocyst complex, which functions in polarized exocytosis, has been involved in the regulation of cell motility. Here, we show a physical and functional connection between exocyst and WRC. Purified components of exocyst and WRC directly associate in vitro, and interactions interfaces are identified. The exocyst-WRC interaction is confirmed in cells by co-immunoprecipitation and is shown to occur independently of the Arp2/3 complex. Disruption of the exocyst-WRC interaction leads to impaired migration. By using time-lapse microscopy coupled to image correlation analysis, we visualized the trafficking of the WRC towards the front of the cell in nascent protrusions. The exocyst is necessary for WRC recruitment at the leading edge and for resulting cell edge movements. This direct link between the exocyst and WRC provides a new mechanistic insight into the spatio-temporal regulation of cell migration.


Assuntos
Movimento Celular , Extensões da Superfície Celular/metabolismo , Complexos Multiproteicos/metabolismo , Proteínas de Transporte Vesicular/metabolismo , Família de Proteínas da Síndrome de Wiskott-Aldrich/metabolismo , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Proteínas do Citoesqueleto/metabolismo , Células HEK293 , Humanos , Ligação Proteica , Subunidades Proteicas/metabolismo
2.
Nat Metab ; 6(9): 1682-1694, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-39122784

RESUMO

The clearance of apoptotic cells, termed efferocytosis, is essential for tissue homeostasis and prevention of autoimmunity1. Although past studies have elucidated local molecular signals that regulate homeostatic efferocytosis in a tissue2,3, whether signals arising distally also regulate homeostatic efferocytosis remains elusive. Here, we show that large peritoneal macrophage (LPM) display impairs efferocytosis in broad-spectrum antibiotics (ABX)-treated, vancomycin-treated and germ-free mice in vivo, all of which have a depleted gut microbiota. Mechanistically, the microbiota-derived short-chain fatty acid butyrate directly boosts efferocytosis efficiency and capacity in mouse and human macrophages, and rescues ABX-induced LPM efferocytosis defects in vivo. Bulk messenger RNA sequencing of butyrate-treated macrophages in vitro and single-cell messenger RNA sequencing of LPMs isolated from ABX-treated and butyrate-rescued mice reveals regulation of efferocytosis-supportive transcriptional programmes. Specifically, we find that the efferocytosis receptor T cell immunoglobulin and mucin domain containing 4 (TIM-4, Timd4) is downregulated in LPMs of ABX-treated mice but rescued by oral butyrate. We show that TIM-4 is required for the butyrate-induced enhancement of LPM efferocytosis capacity and that LPM efferocytosis is impaired beyond withdrawal of ABX. ABX-treated mice exhibit significantly worse disease in a mouse model of lupus. Our results demonstrate that homeostatic efferocytosis relies on distal metabolic signals and suggest that defective homeostatic efferocytosis may explain the link between ABX use and inflammatory disease4-7.


Assuntos
Antibacterianos , Homeostase , Fagocitose , Animais , Camundongos , Fagocitose/efeitos dos fármacos , Antibacterianos/farmacologia , Humanos , Butiratos/farmacologia , Macrófagos Peritoneais/metabolismo , Macrófagos Peritoneais/efeitos dos fármacos , Apoptose/efeitos dos fármacos , Macrófagos/metabolismo , Macrófagos/efeitos dos fármacos , Microbioma Gastrointestinal/efeitos dos fármacos , Camundongos Endogâmicos C57BL , Proteínas de Membrana/metabolismo , Proteínas de Membrana/genética , Eferocitose
3.
Front Immunol ; 12: 665782, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34025667

RESUMO

Tissue-resident macrophages exist in unique environments, or niches, that inform their identity and function. There is an emerging body of literature suggesting that the qualities of this environment, such as the types of cells and debris they eat, the intercellular interactions they form, and the length of time spent in residence, collectively what we call habitare, directly inform their metabolic state. In turn, a tissue-resident macrophage's metabolic state can inform their function, including whether they resolve inflammation and protect the host from excessive perturbations of homeostasis. In this review, we summarize recent work that seeks to understand the metabolic requirements for tissue-resident macrophage identity and maintenance, for how they respond to inflammatory challenges, and for how they perform homeostatic functions or resolve inflammatory insults. We end with a discussion of the emerging technologies that are enabling, or will enable, in situ study of tissue-resident macrophage metabolism.


Assuntos
Interações Hospedeiro-Patógeno/imunologia , Macrófagos/imunologia , Macrófagos/metabolismo , Metabolismo/imunologia , Animais , Biotecnologia , Homeostase , Humanos , Imunidade/imunologia , Inflamação/imunologia , Inflamação/metabolismo , Imagem Molecular
4.
Cells ; 10(10)2021 10 02.
Artigo em Inglês | MEDLINE | ID: mdl-34685617

RESUMO

Autophagy is a physiological degradation process that removes unnecessary or dysfunctional components of cells. It is important for normal cellular homeostasis and as a response to a variety of stresses, such as nutrient deprivation. Defects in autophagy have been linked to numerous human diseases, including cancers. Cancer cells require autophagy to migrate and to invade. Here, we study the intracellular topology of this interplay between autophagy and cell migration by an interdisciplinary live imaging approach which combines micro-patterning techniques and an autophagy reporter (RFP-GFP-LC3) to monitor over time, during directed migration, the back-front spatial distribution of LC3-positive compartments (autophagosomes and autolysosomes). Moreover, by exploiting a genetically controlled cell model, we assessed the impact of transformation by the Ras oncogene, one of the most frequently mutated genes in human cancers, which is known to increase both cell motility and basal autophagy. Static cells displayed an isotropic distribution of autophagy LC3-positive compartments. Directed migration globally increased autophagy and polarized both autophagosomes and autolysosomes at the front of the nucleus of migrating cells. In Ras-transformed cells, the front polarization of LC3 compartments was much less organized, spatially and temporally, as compared to normal cells. This might be a consequence of altered lysosome positioning. In conclusion, this work reveals that autophagy organelles are polarized toward the cell front during migration and that their spatial-temporal dynamics are altered in motile cancer cells that express an oncogenic Ras protein.


Assuntos
Autofagia , Movimento Celular , Genes ras , Oncogenes , Animais , Autofagia/genética , Bovinos , Linhagem Celular , Movimento Celular/genética , Núcleo Celular/efeitos dos fármacos , Núcleo Celular/metabolismo , Transformação Celular Neoplásica/efeitos dos fármacos , Transformação Celular Neoplásica/patologia , Colágeno/farmacologia , Géis/farmacologia , Humanos , Processamento de Imagem Assistida por Computador , Lisossomos/efeitos dos fármacos , Lisossomos/metabolismo , Proteínas Associadas aos Microtúbulos/metabolismo
5.
Cancer Cell ; 39(7): 973-988.e9, 2021 07 12.
Artigo em Inglês | MEDLINE | ID: mdl-34115989

RESUMO

Immune checkpoint blockade (ICB) has been a remarkable clinical advance for cancer; however, the majority of patients do not respond to ICB therapy. We show that metastatic disease in the pleural and peritoneal cavities is associated with poor clinical outcomes after ICB therapy. Cavity-resident macrophages express high levels of Tim-4, a receptor for phosphatidylserine (PS), and this is associated with reduced numbers of CD8+ T cells with tumor-reactive features in pleural effusions and peritoneal ascites from patients with cancer. We mechanistically demonstrate that viable and cytotoxic anti-tumor CD8+ T cells upregulate PS and this renders them susceptible to sequestration away from tumor targets and proliferation suppression by Tim-4+ macrophages. Tim-4 blockade abrogates this sequestration and proliferation suppression and enhances anti-tumor efficacy in models of anti-PD-1 therapy and adoptive T cell therapy in mice. Thus, Tim-4+ cavity-resident macrophages limit the efficacy of immunotherapies in these microenvironments.


Assuntos
Linfócitos T CD8-Positivos/imunologia , Neoplasias do Colo/imunologia , Regulação Neoplásica da Expressão Gênica , Macrófagos/imunologia , Proteínas de Membrana/metabolismo , Microambiente Tumoral , Animais , Apoptose , Proliferação de Células , Neoplasias do Colo/metabolismo , Neoplasias do Colo/patologia , Feminino , Humanos , Proteínas de Membrana/genética , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Prognóstico , Estudos Retrospectivos , Células Tumorais Cultivadas , Ensaios Antitumorais Modelo de Xenoenxerto
6.
Small GTPases ; 10(5): 323-330, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-28498728

RESUMO

Cell migration is central to many developmental, physiologic and pathological processes, including cancer progression. The Ral GTPases (RalA and RalB) which act down-stream the Ras oncogenes, are key players in the coordination between membrane trafficking and actin polymerization. A major direct effector of Ral, the exocyst complex, works in polarized exocytosis and is at the center of multiple protein-protein interactions that support cell migration by promoting protrusion formation, front-rear polarization, and extra-cellular matrix degradation. In this review we describe the recent advancements in deciphering the molecular mechanisms underlying this role of Ral via exocyst on cell migration. Among others, we will discuss the recently identified cross-talk between Ral and Rac1 pathways: exocyst binds to a negative regulator (the RacGAP SH3BP1) and to the major effector (the Wave Regulatory Complex, WRC) of Rac1, the master regulator of protrusions. Next challenge will be to better characterize the dynamics in space and in time of these molecular interplays, to better understand the pleiotropic functions of Ral in both normal and cancer cells.


Assuntos
Movimento Celular , Proteínas de Neoplasias/metabolismo , Neoplasias/metabolismo , Transdução de Sinais , Proteínas rac1 de Ligação ao GTP/metabolismo , Proteínas ral de Ligação ao GTP/metabolismo , Proteínas ras/metabolismo , Animais , Proteínas Ativadoras de GTPase , Humanos , Neoplasias/patologia
7.
Sci Rep ; 9(1): 8910, 2019 06 20.
Artigo em Inglês | MEDLINE | ID: mdl-31222145

RESUMO

The monomeric GTPase RalB controls crucial physiological processes, including autophagy and invasion, but it still remains unclear how this multi-functionality is achieved. Previously, we reported that the RalGEF (Guanine nucleotide Exchange Factor) RGL2 binds and activates RalB to promote invasion. Here we show that RGL2, a major activator of RalB, is also required for autophagy. Using a novel automated image analysis method, Endomapper, we quantified the endogenous localization of the RGL2 activator and its substrate RalB at different endomembrane compartments, in an isogenic normal and Ras-transformed cell model. In both normal and Ras-transformed cells, we observed that RGL2 and RalB substantially localize at early and recycling endosomes, and to lesser extent at autophagosomes, but not at trans-Golgi. Interestingly the use of a FRET-based RalB biosensor indicated that RalB signaling is active at these endomembrane compartments at basal level in rich medium. Furthermore, induction of autophagy by nutrient starvation led to a considerable reduction of early and recycling endosomes, in contrast to the expected increase of autophagosomes, in both normal and Ras-transformed cells. However, autophagy mildly affected relative abundances of both RGL2 and RalB at early and recycling endosomes, and at autophagosomes. Interestingly, RalB activity increased at autophagosomes upon starvation in normal cells. These results suggest that the contribution of endosome membranes (carrying RGL2 and RalB molecules) increases total pool of RGL2-RalB at autophagosome forming compartments and might contribute to amplify RalB signaling to support autophagy.


Assuntos
Autofagia/fisiologia , Transdução de Sinais , Proteínas ral de Ligação ao GTP/metabolismo , Compartimento Celular , Fatores de Troca do Nucleotídeo Guanina/metabolismo , Humanos , Membranas Intracelulares/metabolismo , Transporte Proteico , Proteínas ral de Ligação ao GTP/fisiologia
8.
Sci Rep ; 9(1): 11797, 2019 Aug 08.
Artigo em Inglês | MEDLINE | ID: mdl-31395941

RESUMO

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

9.
J Palliat Med ; 22(6): 691-695, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30888908

RESUMO

Background: Neoplastic pericardial effusion (NPE) is a life-threatening condition that can worsen clinical outcome in cancer patients. The optimal management of NPE has yet to be defined because randomized studies are lacking. Objective: We report a retrospective monoinstitutional experience describing characteristics, management and prognostic factors in NPE patients. Design: We reviewed clinical, pathological, and echocardiographic features, therapeutic strategies, and outcome in NPE patients referred to our institute from August 2011 to December 2017. Measurements: Twenty-nine patients with NPE from solid tumors have been identified: 21 lung, 5 breast, and 3 other cancer patients. Results: Median age was 62 years. Most of the patients had Eastern Cooperative Oncology Group (ECOG) performance status (PS) ≥2 (69%) and a symptomatic NPE (69%). In 52% of patients NPE was detected at first diagnosis of metastatic disease, and in 20% of patients pericardium was the only site of metastases. Most of the patients (62%) received systemic therapy, 28% received combined locoregional and systemic therapy, and 10% received locoregional therapy alone. Median overall survival (OS) from NPE diagnosis was 3.9 months. Patients with PS ≥2 had worse OS than patients with better PS <2 (hazard ratio [HR] 3.56, IC 95% 1.19-10.65, p 0.02). Older age, extrapericardial disease, and NPE at progression showed a trend of association with worse OS. Patients treated with locoregional therapy alone showed the shortest median OS (p 0.05). Conclusions: NPE is related to dismal prognosis. Poor PS significantly worsens survival and influences therapeutic approaches. Randomized studies are required to investigate prognostic factors and appropriate clinical management for patients with NPE.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Neoplasias/complicações , Neoplasias/tratamento farmacológico , Derrame Pericárdico/etiologia , Derrame Pericárdico/terapia , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Prognóstico , Estudos Retrospectivos
11.
Elife ; 72018 10 15.
Artigo em Inglês | MEDLINE | ID: mdl-30320548

RESUMO

The two Ral GTPases, RalA and RalB, have crucial roles downstream Ras oncoproteins in human cancers; in particular, RalB is involved in invasion and metastasis. However, therapies targeting Ral signalling are not available yet. By a novel optogenetic approach, we found that light-controlled activation of Ral at plasma-membrane promotes the recruitment of the Wave Regulatory Complex (WRC) via its effector exocyst, with consequent induction of protrusions and invasion. We show that active Ras signals to RalB via two RalGEFs (Guanine nucleotide Exchange Factors), RGL1 and RGL2, to foster invasiveness; RalB contribution appears to be more important than that of MAPK and PI3K pathways. Moreover, on the clinical side, we uncovered a potential role of RalB in human breast cancers by determining that RalB expression at protein level increases in a manner consistent with progression toward metastasis. This work highlights the Ras-RGL1/2-RalB-exocyst-WRC axis as appealing target for novel anticancer strategies.


Assuntos
Família de Proteínas da Síndrome de Wiskott-Aldrich/metabolismo , Proteínas ral de Ligação ao GTP/metabolismo , Proteínas ras/metabolismo , Neoplasias da Mama/metabolismo , Neoplasias da Mama/patologia , Linhagem Celular , Membrana Celular/metabolismo , Membrana Celular/efeitos da radiação , Extensões da Superfície Celular/metabolismo , Extensões da Superfície Celular/efeitos da radiação , Progressão da Doença , Feminino , Humanos , Luz , Invasividade Neoplásica , Optogenética , Transdução de Sinais
12.
Oncotarget ; 8(27): 44232-44241, 2017 Jul 04.
Artigo em Inglês | MEDLINE | ID: mdl-28562336

RESUMO

Malignant Pleural Mesothelioma (MPM) is a chemoresistant tumor characterized by low rate of p53 mutation and upregulation of Murine Double Minute 2 (MDM2), suggesting that it may be effectively targeted using MDM2 inhibitors. In the present study, we investigated the anticancer activity of the MDM2 inhibitors Nutlin 3a (in vitro) and RG7112 (in vivo), as single agents or in combination with rhTRAIL.In vitro studies were performed using MPM cell lines derived from epithelioid (ZL55, M14K), biphasic (MSTO211H) and sarcomatoid (ZL34) MPMs. In vivo studies were conducted on a sarcomatoid MPM mouse model.In all the cell lines tested (with the exception of ZL55, which carries a biallelic loss-of-function mutation of p53), Nutlin 3a enhanced p21, MDM2 and DR5 expression, and decreased survivin expression. These changes were associated to cell cycle arrest but not to a significant induction of apoptosis. A synergistic pro-apoptotic effect was obtained through the association of rhTRAIL in all the cell lines harboring functional p53. This synergistic interaction of MDM2 inhibitor and TRAIL agonist was confirmed using a mouse preclinical model. Our results suggest that the combined targeting of MDM2 and TRAIL might provide a novel therapeutic option for treatment of MPM patients, particularly in the case of sarcomatoid MPM with MDM2 overexpression and functional inactivation of wild-type p53.


Assuntos
Antineoplásicos/farmacologia , Neoplasias Pulmonares/metabolismo , Mesotelioma/metabolismo , Neoplasias Pleurais/metabolismo , Inibidores de Proteínas Quinases/farmacologia , Proteínas Proto-Oncogênicas c-mdm2/metabolismo , Ligante Indutor de Apoptose Relacionado a TNF/agonistas , Animais , Apoptose/efeitos dos fármacos , Biomarcadores Tumorais , Pontos de Checagem do Ciclo Celular/genética , Linhagem Celular Tumoral , Sinergismo Farmacológico , Humanos , Imidazóis/metabolismo , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/patologia , Mesotelioma/tratamento farmacológico , Mesotelioma/genética , Mesotelioma/patologia , Mesotelioma Maligno , Camundongos , Mutação , Piperazinas/metabolismo , Neoplasias Pleurais/tratamento farmacológico , Neoplasias Pleurais/genética , Neoplasias Pleurais/patologia , Ligante Indutor de Apoptose Relacionado a TNF/farmacologia
13.
Oncotarget ; 8(20): 32626-32638, 2017 May 16.
Artigo em Inglês | MEDLINE | ID: mdl-28427238

RESUMO

INTRODUCTION: Tyrosine-kinase inhibitors (TKIs) represent the best treatment for advanced non-small cell lung cancer (NSCLC) with common exon 19 deletion or exon 21 epidermal growth factor receptor mutation (EGFRm). This is an observational study investigating epidemiology, clinical features and treatment outcome of NSCLC cases harbouring rare/complex EGFRm. RESULTS: Among 764 non-squamous NSCLC cases with known EGFRm status, 26(3.4%) harboured rare/complex EGFRm. Patients receiving first-line TKIs (N = 17) achieved median Progression Free Survival (PFS) and Overall Survival (OS) of 53 (IC 95%, 2-105) and 84 (CI 95%, 27-141) weeks respectively, without significant covariate impact. Response Rate and Disease Control Rate (DCR) were 47% and 65%, respectively. Uncommon exon 19 mutations achieved longer OS and PFS and higher DCR compared with exon 18 and 20 mutations. No additional gene mutation was discovered by MassARRAY analysis. TKIs were globally well tolerated. MATERIALS AND METHODS: A retrospective review of advanced non-squamous NSCLC harbouring rare/complex EGFRm referred to our Center between 2010 and 2015 was performed. Additional molecular pathways disregulation was explored in selected cases, through MassARRAY analysis. CONCLUSIONS: Peculiar clinical features and lower TKIs sensitivity of uncommon/complex compared with common EGFRm were shown. Exon 19 EGFRm achieved the best TKIs treatment outcome, while the optimal treatment of exon 18 and 20 mutations should be further clarified.


Assuntos
Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Carcinoma Pulmonar de Células não Pequenas/genética , Receptores ErbB/genética , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/genética , Inibidores de Proteínas Quinases/uso terapêutico , Idoso , Idoso de 80 Anos ou mais , Carcinoma Pulmonar de Células não Pequenas/enzimologia , Carcinoma Pulmonar de Células não Pequenas/patologia , Feminino , Humanos , Neoplasias Pulmonares/enzimologia , Neoplasias Pulmonares/patologia , Masculino , Pessoa de Meia-Idade , Mutação , Estudos Retrospectivos , Resultado do Tratamento
14.
Biologics ; 10: 103-17, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27536062

RESUMO

Non-small-cell lung cancer (NSCLC) is often diagnosed at an advanced stage of disease, where it is no longer amenable to curative treatment. During the last decades, the survival has only improved significantly for lung cancer patients who have tumors harboring a driver mutation. Therefore, there is a clear unmet need for effective therapies for patients with no mutation. Immunotherapy has emerged as an effective treatment for different cancer types. Nivolumab, a monoclonal inhibitory antibody against PD-1 receptor, can prolong survival of NSCLC patients, with a manageable toxicity profile. In two Phase III trials, nivolumab was compared to docetaxel in patients with, respectively, squamous (CheckMate 017) and non-squamous NSCLC (CheckMate 057). In both trials, nivolumab significantly reduced the risk of death compared to docetaxel (41% and 27% lower risk of death for squamous and non-squamous NSCLC, respectively). Therefore, nivolumab has been approved in the US and in Europe as second-line treatment for advanced NSCLC. Unfortunately, accurate predictive factors for patient selection are lacking, making it difficult to decide who will benefit and who will not. Currently, there are many ongoing trials that evaluate the efficacy of nivolumab in different settings and in combination with other agents. This paper reviews the present literature about the role of nivolumab in the treatment of NSCLC. Particular attention has been given to efficacy studies, toxicity profile, and current and emerging predictive factors.

15.
Onco Targets Ther ; 9: 3671-81, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27382305

RESUMO

OBJECTIVES: If concurrent chemoradiotherapy cannot be performed, induction chemotherapy followed by radical-intent surgical treatment is an acceptable option for non primarily resectable non-small-cell lung cancers (NSCLCs). No markers are available to predict which patients may benefit from local treatment after induction. This exploratory study aims to assess the feasibility and the activity of multimodality treatment, including triple-agent chemotherapy followed by radical surgery and/or radiotherapy in locally advanced NSCLCs. METHODS: We retrospectively collected data from locally advanced NSCLCs treated with induction chemotherapy with carboplatin (area under the curve 6, d [day]1), paclitaxel (200 mg/m(2), d1), and gemcitabine (1,000 mg/m(2) d1, 8) for three to four courses, followed by radical surgery and/or radiotherapy. We analyzed radiological response and toxicity. Estimated progression-free survival (PFS) and overall survival (OS) were correlated to response, surgery, and clinical features. RESULTS: In all, 58 NSCLCs were included in the study: 40 staged as IIIA, 18 as IIIB (according to TNM Classification of Malignant Tumors-7th edition staging system). A total of 36 (62%) patients achieved partial response (PR), and six (10%) progressions were recorded. Grade 3-4 hematological toxicity was observed in 36 (62%) cases. After chemotherapy, 37 (64%) patients underwent surgery followed by adjuvant radiotherapy, and two patients received radical-intent radiotherapy. The median PFS and OS were 11 months and 23 months, respectively. Both PFS and OS were significantly correlated to objective response (P<0.0001) and surgery (P<0.0001 and P=0.002). Patients obtaining PR and receiving local treatment achieved a median PFS and OS of 35 and 48 months, respectively. Median PFS and OS of patients not achieving PR or not receiving local treatment were 5-7 and 11-15 months, respectively. The extension of surgery did not affect the outcome. CONCLUSION: The multimodality treatment was feasible, and triple-agent induction was associated with a considerable rate of PR. Patients achieving PR and receiving radical surgery or radiotherapy (53%) achieved a median OS of 4 years.

16.
Oncotarget ; 7(28): 44142-44160, 2016 Jul 12.
Artigo em Inglês | MEDLINE | ID: mdl-27283898

RESUMO

Oncogenic Ras signalling occurs frequently in many human cancers. However, no effective targeted therapies are currently available to treat patients suffering from Ras-driven tumours. Therefore, it is imperative to identify downstream effectors of Ras signalling that potentially represent promising new therapeutic options. Particularly, considering that autophagy inhibition can impair the survival of Ras-transformed cells in tissue culture and mouse models, an understanding of factors regulating the balance between autophagy and apoptosis in Ras-transformed human cells is needed. Here, we report critical roles of the STK38 protein kinase in oncogenic Ras transformation. STK38 knockdown impaired anoikis resistance, anchorage-independent soft agar growth, and in vivo xenograft growth of Ras-transformed human cells. Mechanistically, STK38 supports Ras-driven transformation through promoting detachment-induced autophagy. Even more importantly, upon cell detachment STK38 is required to sustain the removal of damaged mitochondria by mitophagy, a selective autophagic process, to prevent excessive mitochondrial reactive oxygen species production that can negatively affect cancer cell survival. Significantly, knockdown of PINK1 or Parkin, two positive regulators of mitophagy, also impaired anoikis resistance and anchorage-independent growth of Ras-transformed human cells, while knockdown of USP30, a negative regulator of PINK1/Parkin-mediated mitophagy, restored anchorage-independent growth of STK38-depleted Ras-transformed human cells. Therefore, our findings collectively reveal novel molecular players that determine whether Ras-transformed human cells die or survive upon cell detachment, which potentially could be exploited for the development of novel strategies to target Ras-transformed cells.


Assuntos
Transformação Celular Neoplásica/genética , Mitofagia/genética , Proteínas Serina-Treonina Quinases/genética , Proteínas ras/genética , Animais , Anoikis/genética , Apoptose/genética , Autofagia/genética , Linhagem Celular , Linhagem Celular Tumoral , Células HCT116 , Células HEK293 , Humanos , Camundongos Nus , Proteínas Serina-Treonina Quinases/metabolismo , Interferência de RNA , Transplante Heterólogo , Ubiquitina-Proteína Ligases/genética , Ubiquitina-Proteína Ligases/metabolismo , Proteínas ras/metabolismo
17.
Am J Case Rep ; 16: 782-9, 2015 Nov 03.
Artigo em Inglês | MEDLINE | ID: mdl-26525068

RESUMO

BACKGROUND: Lung cancer in young patients is quite uncommon; clinical presentation and outcome in this population compared to the older group are not yet well defined and data about this setting are mostly single-institutional retrospective analyses. CASE REPORT: We report here a case of a very young woman with diagnosis of early-stage lung adenocarcinoma harboring EML4-ALK rearrangement; she underwent radical surgery and adjuvant chemotherapy according to the pathologic stage. Potential risk factors for lung cancer in our patient are discussed and clinico-pathologic features and outcomes of lung cancer in the young population compared to the elderly are reviewed through discussing studies with sample sizes larger than 100 patients. CONCLUSIONS: A wide clinical overview should be performed when lung cancer is diagnosed in a young patient. Large-population studies are required to define the molecular signature and clinical behavior of lung cancer in young patients.


Assuntos
Carcinoma Pulmonar de Células não Pequenas/diagnóstico , Neoplasias Pulmonares/diagnóstico , Carcinoma Pulmonar de Células não Pequenas/genética , Carcinoma Pulmonar de Células não Pequenas/cirurgia , DNA de Neoplasias/análise , Feminino , Rearranjo Gênico , Testes Genéticos , Humanos , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/cirurgia , Proteínas de Fusão Oncogênica/genética , Proteínas de Fusão Oncogênica/metabolismo , Pneumonectomia , Cirurgia Torácica Vídeoassistida , Tomografia Computadorizada por Raios X , Adulto Jovem
18.
Anticancer Res ; 35(4): 2183-9, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25862876

RESUMO

BACKGROUND/AIM: Most patients with small cell lung cancer (SCLC) experience relapse within one year after first-line treatment. The aim of this study was to describe activity and safety of second-line with epirubicin at 70 mg/m(2) followed by paclitaxel at 135 mg/m(2) on day 1 every three weeks for a maximum of six cycles. PATIENTS AND METHODS: This is a retrospective review of all patients with SCLC evaluated for second-line treatment between 2003 and 2013 at our Institution. RESULTS: Sixty-eight patients received the study regimen of epirubicin with paclitaxel. We observed partial response in 19 (30%), stable disease in 22 (34%) and total early failure rate in 23 (36%) patients. Median progression free and overall survival were 21.8 and 26.5 weeks, respectively. Haematological toxicities were as follows: grade 3-4 leukopenia and neutropenia in 18 (31%) and 30 (22%) of patients, respectively; grade 3 anaemia and grade 4 thrombocytopenia were reported in 2 (3%) and 5 (9%) of patients, respectively. CONCLUSION: Epirubicin with paclitaxel is an active and tolerable second-line regimen in patients with SCLC.


Assuntos
Epirubicina/administração & dosagem , Recidiva Local de Neoplasia/tratamento farmacológico , Paclitaxel/administração & dosagem , Carcinoma de Pequenas Células do Pulmão/tratamento farmacológico , Adulto , Idoso , Idoso de 80 Anos ou mais , Protocolos de Quimioterapia Combinada Antineoplásica , Cisplatino/administração & dosagem , Cisplatino/efeitos adversos , Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos/classificação , Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos/patologia , Epirubicina/efeitos adversos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Recidiva Local de Neoplasia/patologia , Paclitaxel/efeitos adversos , Carcinoma de Pequenas Células do Pulmão/patologia
19.
Clin Nucl Med ; 39(2): e135-41, 2014 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-24398430

RESUMO

BACKGROUND: We aim to retrospectively evaluate the impact of hormone therapy (HT) on FDG avidity of metastatic lesions in patients with breast cancer (BC) undergoing PET/CT. PATIENTS AND METHODS: Three hundred eight patients with BC were scanned with PET/CT at 2 Italian institutions (mean time from diagnosis 4 yrs, range: 1-24 yrs). Main indications for PET/CT were elevation of tumor markers (34.4%) and clinical or radiological suspicion of relapse (65.6%). The diagnostic accuracy of FDG PET/CT was computed according to the standard method. Student t test was used to assess the mean differences between the study groups, whereas categorical data were compared with chi-square test. Significance was set at P <0.05. RESULTS: Two hundred sixty-four patients with positive estrogen receptor and who had received adjuvant HT were included in the analysis. At the time of PET/CT scan, HT was ongoing in 176 patients (66.7%) and 88 (33.3%) had completed adjuvant HT. Ninety-eight (55.7%) patients on HT and 59 (67%) off HT had a positive PET/CT; therefore, the scan resulted negative in the remaining 107 patients, 78 and 29 on and off HT, 44.3% and 33%, respectively (P < 0.001). At a median follow-up of 7 months (range 1-48 mos), disease recurrence was confirmed in either clinical or radiological examinations in 126 (47.7%) patients; 72 (40.9%) versus 54 (61.4%) patients on and off HT, respectively (P < 0.005). True-positive PET/CT results were found in 82% and 91% of patients on and off HT, respectively, whereas it failed to identify disease relapse in 13 (18%) and 5 (9%) patients on and off HT, respectively. CONCLUSIONS: In our series, FDG PET/CT shows a similar diagnostic accuracy in detecting disease relapse between patients with BC on adjuvant HT versus those who have completed therapy. These preliminary results suggest that the glucose metabolism is not altered by hormonal suppression at the time of the scan.


Assuntos
Neoplasias da Mama/diagnóstico , Neoplasias da Mama/tratamento farmacológico , Fluordesoxiglucose F18 , Hormônios/uso terapêutico , Imagem Multimodal , Tomografia por Emissão de Pósitrons , Tomografia Computadorizada por Raios X , Adulto , Idoso , Idoso de 80 Anos ou mais , Animais , Neoplasias da Mama/metabolismo , Neoplasias da Mama/patologia , Quimioterapia Adjuvante , Feminino , Fluordesoxiglucose F18/metabolismo , Humanos , Masculino , Pessoa de Meia-Idade , Metástase Neoplásica , Estudos Retrospectivos
20.
Autophagy ; 10(12): 2122-42, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25427136

RESUMO

The triple-negative breast cancer (TN BC) subtype is the most aggressive form of invasive BC. Despite intensive efforts to improve BC treatments, patients with TN BC continue to exhibit poor survival, with half developing resistance to chemotherapy. Here we identify autophagy as a key mechanism in the progression and chemoresistance of a subset of TN tumors. We demonstrate that LC3B, a protein involved in autophagosome formation, is a reliable marker of poor prognosis in TN BC, validating this prognostic value at both the mRNA and protein levels in several independent cohorts. We also show that LC3B has no prognostic value for other BC subtypes (Luminal or HER2 BC), thus revealing a specific impact of autophagy on TN tumors. Autophagy is essential for the proliferative and invasive properties in 3D of TN BC cells characterized by high LC3B levels. Interestingly, the activity of the transcriptional co-activator YAP1 (Yes-associated protein 1) is regulated by the autophagy process and we identify YAP1 as a new actor in the autophagy-dependent proliferative and invasive properties of high-LC3B TN BC. Finally, inhibiting autophagy by silencing ATG5 or ATG7 significantly impaired high-LC3B TN tumor growth in vivo. Moreover, using a patient-derived TN tumor transplanted into mice, we show that an autophagy inhibitor, chloroquine, potentiates the effects of chemotherapeutic agents. Overall, our data identify LC3B as a new prognostic marker for TN BC and the inhibition of autophagy as a promising therapeutic strategy for TN BC patients.


Assuntos
Antineoplásicos/uso terapêutico , Autofagia/efeitos dos fármacos , Biomarcadores Tumorais/metabolismo , Neoplasias de Mama Triplo Negativas/diagnóstico , Neoplasias de Mama Triplo Negativas/terapia , Animais , Feminino , Humanos , Camundongos , Proteínas Associadas aos Microtúbulos/metabolismo , Prognóstico , Receptor ErbB-2/metabolismo , Receptores de Estrogênio/efeitos dos fármacos , Receptores de Estrogênio/metabolismo , Resultado do Tratamento
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