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2.
Mol Cancer ; 19(1): 16, 2020 Jan 27.
Artigo em Inglês | MEDLINE | ID: mdl-31987050

RESUMO

Since the publication of this work [1] and in response to a recent query that was brought to our attention in relation to the Western Blot in Figure 1(C) for NP2, protein lysates prepared around the same time as those presented in the manuscript in question, were run by SDS-PAGE under similar experimental conditions and probed using the same primary antibodies to NP1 and NP2 that were used originally.

3.
Lung Cancer ; 135: 217-227, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31446998

RESUMO

OBJECTIVES: The majority of patients with non-small cell lung cancer (NSCLC) present with advanced stage disease, at which time chemotherapy is usually the most common treatment option. While somewhat effective, patients treated with platinum-based regimens will eventually develop resistance, with others presenting with intrinsic resistance. Multiple pathways have been implicated in chemo-resistance, however the critical underlying mechanisms have yet to be elucidated. The aim of this project was to determine the role of inflammatory mediators in cisplatin-resistance in NSCLC. MATERIALS AND METHODS: Inflammatory mediator, NF-κB, and its associated pathways were investigated in an isogenic model of cisplatin-resistant NSCLC using age-matched parental (PT) and corresponding cisplatin-resistant (CisR) sublines. Pathways were assessed using mass spectrometry, western blot analysis and qRT-PCR. The cisplatin sensitizing potential of an NF-κB small molecule inhibitor, DHMEQ, was also assessed by means of viability assays and western blot analysis. RESULTS: Proteomic analysis identified dysregulated NF-κB responsive targets in CisR cells when compared to PT cells, with increased NF-κB expression identified in four out of the five NSCLC sub-types examined (CisR versus PT). DHMEQ treatment resulted in reduced NF-κB expression in the presence of cisplatin, and re-sensitized CisR cells to the cytotoxic effects of the drug. CONCLUSION: This study identified NF-ĸB as a potential therapeutic target in cisplatin-resistant NSCLC. Furthermore, inhibition of NF-ĸB using DHMEQ re-sensitized chemo-resistant cells to cisplatin treatment.

4.
Artigo em Inglês | MEDLINE | ID: mdl-30863365

RESUMO

Malignant pleural mesothelioma (MPM) is an aggressive inflammatory cancer with a poor survival rate. Treatment options are limited at best and drug resistance is common. Thus, there is an urgent need to identify novel therapeutic targets in this disease in order to improve patient outcomes and survival times. MST1R (RON) is a trans-membrane receptor tyrosine kinase (RTK), which is part of the c-MET proto-oncogene family. The only ligand recognized to bind MST1R (RON) is Macrophage Stimulating 1 (MST1), also known as Macrophage Stimulating Protein (MSP) or Hepatocyte Growth Factor-Like Protein (HGFL). In this study, we demonstrate that the MST1-MST1R (RON) signaling axis is active in MPM. Targeting this pathway with a small molecule inhibitor, LCRF-0004, resulted in decreased proliferation with a concomitant increase in apoptosis. Cell cycle progression was also affected. Recombinant MST1 treatment was unable to overcome the effect of LCRF-0004 in terms of either proliferation or apoptosis. Subsequently, the effect of an additional small molecular inhibitor, BMS-777607 (which targets MST1R (RON), MET, Tyro3, and Axl) also resulted in a decreased proliferative capacity of MPM cells. In a cohort of MPM patient samples, high positivity for total MST1R by IHC was an independent predictor of favorable prognosis. Additionally, elevated expression levels of MST1 also correlated with better survival. This study also determined the efficacy of LCRF-0004 and BMS-777607 in xenograft MPM models. Both LCRF-0004 and BMS-777607 demonstrated significant anti-tumor efficacy in vitro, however BMS-777607 was far superior to LCRF-0004. The in vivo and in vitro data generated by this study indicates that a multi-TKI, targeting the MST1R/MET/TAM signaling pathways, may provide a more effective therapeutic strategy for the treatment of MPM as opposed to targeting MST1R alone.

5.
Am J Cancer Res ; 8(8): 1514-1527, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30210920

RESUMO

In addition to direct oncolysis, oncolytic viruses trigger immunogenic cell death (ICD) and primes antitumor immunity. We have previously shown that oncolytic Newcastle disease virus (NDV), strain FMW (NDV/FMW), induces apoptosis and/or autophagy in cancer cells. In this study, we investigated whether oncolytic NDV can induce ICD in lung cancer cells and whether apoptosis or autophagy plays a role in NDV-triggered ICD. To this end, we examined cell surface expression of calreticulin (CRT) on NDV-infected lung cancer cells and measured ICD determinants, high mobility group box 1 (HMGB1), heat shock protein 70/90 (HSP70/90) and ATP in supernatants following viral infection. Flow cytometric analysis using anti-CRT antibody and PI staining of NDV-infected lung cancer cells showed an increase in the number of viable (propidium iodide-negative) cells, suggesting the induction of CRT exposure upon NDV infection. In addition, confocal and immunoblot analysis using anti-CRT antibody showed that an enhanced accumulation of CRT on the cell surface of NDV-infected cells, indicating the translocation of CRT to the cell membrane upon NDV infection. We further demonstrated that NDV infection induced the release of secreted HMGB1 and HSP70/90 by examining the concentrated supernatants of NDV-infected cells. Furthermore, pre-treatment with either the pan-caspase inhibitor z-VAD-FMK or the necrosis inhibitor Necrostain-1, had no impact on NDV-induced release of ICD determinants in lung cancer cells. Rather, depletion of autophagy-related genes in lung cancer cells significantly inhibited the induction of ICD determinants by NDV. Of translational importance, in a lung cancer xenograft model, treatment of mice with supernatants from NDV-infected cells significantly inhibited tumour growth. Together, these results indicate that oncolytic NDV is a potent ICD-inducer and that autophagy contributes to NDV-mediated induction of ICD in lung cancer cells.

6.
J Exp Clin Cancer Res ; 37(1): 165, 2018 Jul 24.
Artigo em Inglês | MEDLINE | ID: mdl-30041665

RESUMO

BACKGROUND: Aberrant activation of ß-catenin and Yes-associated protein (YAP) signaling pathways has been associated with hepatocellular carcinoma (HCC) progression. The LIM domain protein Ajuba regulates ß-catenin and YAP signaling and is implicated in tumorigenesis. However, roles and mechanism of Ajuba expression in HCC cells remain unclear. The E3 ligase Hakai has been shown to interact with other Ajuba family members and whether Hakai interacts and regulates Ajuba is unknown. METHODS: HCC cell lines stably depleted of Ajuba or Hakai were established using lentiviruses expressing shRNAs against Ajuba or Hakai. The effects of Ajuba on HCC cells were determined by a number of cell-based analyses including anchorage-independent growth, three dimension cultures and trans-well invasion assay. In vivo tumor growth was determined in a xenograft model and Ajuba expression in tumor sections was examined by immunohistochemistry. Co-immunoprecipitation, confocal microscopy and immunoblot assay were used to examine the expression and interaction between Ajuba and Hakai. RESULTS: Depletion of Ajuba in HCC cells significantly enhanced anchorage-independent growth, invasion, the formation of spheroids and tumor growth in a xenograft model, suggesting a tumor suppressor function for Ajuba in HCC. Mechanistically, Ajuba depletion triggered E-cadherin loss and ß-catenin translocation with increased Cyclin D1 levels. In addition, depletion of Ajuba upregulated the levels of YAP and its target gene CYR61. Furthermore, siRNA-mediated knockdown of either ß-catenin or YAP attenuated the pro-tumor effects by Ajuba depletion on HCC cells. Notably, Ajuba stability in HCC cells was regulated by Hakai, an E3 ligase for E-cadherin. Hakai interacted with Ajuba via its HYB domain and induced Ajuba neddylation, which was antagonized by the neddylation inhibitor, MLN4924, but not MG132. We further show that overexpression of Hakai in HCC cells markedly increased anchorage-independent growth, spheroid-formation ability and tumor growth in xenografts whereas Hakai depletion resulted in these opposite effects, indicating an oncogenic role for Hakai in HCC. Hakai also induced ß-catenin translocation with increased levels of Cyclin D1. CONCLUSIONS: Our data suggest a role for Ajuba and Hakai in HCC, and uncover the mechanism underlying the regulation of Ajuba stability.


Assuntos
Carcinoma Hepatocelular/genética , Proteínas com Domínio LIM/genética , Neoplasias Hepáticas/genética , Ubiquitina-Proteína Ligases/metabolismo , beta Catenina/metabolismo , Animais , Carcinoma Hepatocelular/patologia , Linhagem Celular Tumoral , Humanos , Proteínas com Domínio LIM/metabolismo , Neoplasias Hepáticas/patologia , Camundongos , Camundongos Nus , Transfecção
7.
BMC Cancer ; 18(1): 746, 2018 Jul 18.
Artigo em Inglês | MEDLINE | ID: mdl-30021550

RESUMO

BACKGROUND: Anaplastic thyroid cancer (ATC) is one of the most aggressive of all solid tumors for which no effective therapies are currently available. Oncolytic Newcastle disease virus (NDV) has shown the potential to induce oncolytic cell death in a variety of cancer cells of diverse origins. However, whether oncolytic NDV displays antitumor effects in ATC remains to be investigated. We have previously shown that the oncolytic NDV strain FMW (NDV/FMW) induces oncolytic cell death in several cancer types. In the present study, we investigated the oncolytic effects of NDV/FMW in ATC. METHODS: In this study, a recombinant NDV expressing green fluorescent protein (GFP) was generated using an NDV reverse genetics system. The resulting virus was named after rFMW/GFP and the GFP expression in infected cells was demonstrated by direct fluorescence and immunoblotting. Viral replication was evaluated by end-point dilution assay in DF-1 cell lines. Oncolytic effects were examined by biochemical and morphological experiments in cultural ATC cells and in mouse models. RESULTS: rFMW/GFP replicated robustly in ATC cells as did its parent virus (NDV/FMW) while the expression of GFP protein was detected in lungs and spleen of mice intravenously injected with rFMW/GFP. We further showed that rFMW/GFP infection substantially increased early and late apoptosis in the ATC cell lines, THJ-16 T and THJ-29 T and increased caspase-3 processing and Poly (ADP-ribose) polymerase (PARP) cleavage in ATC cells as assessed by immunoblotting. In addition, rFMW/GFP induced lyses of spheroids derived from ATC cells in three-dimensional (3D) cultures. We further demonstrated that rFMW/GFP infection resulted in the activation of p38 MAPK signaling, but not Erk1/2 or JNK, in THJ-16 T and THJ-29 T cells. Notably, inhibition of p38 MAPK activity by SB203580 decreased rFMW/GFP-induced cleavage of caspase-3 and PARP in THJ-16 T and THJ-29 T cells. Finally, both rFMW/GFP and its parent virus inhibited tumor growth in mice bearing THJ-16 T derived tumors. CONCLUSION: Taken together, these data indicate that both the recombinant reporter virus rFMW/GFP and its parent virus NDV/FMW, display oncolytic activities in ATC cells in vitro and in vivo and suggest that oncolytic NDV may have potential as a novel therapeutic strategy for ATC.


Assuntos
Vírus da Doença de Newcastle/fisiologia , Terapia Viral Oncolítica , Vírus Oncolíticos/fisiologia , Carcinoma Anaplásico da Tireoide/terapia , Animais , Linhagem Celular Tumoral , Embrião de Galinha , Feminino , Sistema de Sinalização das MAP Quinases/fisiologia , Camundongos , Recombinação Genética , Replicação Viral , Proteínas Quinases p38 Ativadas por Mitógeno/fisiologia
9.
Cancer Lett ; 428: 117-126, 2018 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-29653268

RESUMO

Non-small cell lung cancer (NSCLC) is the most common cause of cancer-related deaths worldwide. While partial or complete tumor regression can be achieved in patients, particularly with cisplatin-based strategies, these initial responses are frequently short-lived and are followed by tumor relapse and chemoresistance. Identifying the root of cisplatin resistance in NSCLC and elucidating the mechanism(s) of tumor relapse, is of critical importance in order to determine the point of therapeutic failure, which in turn, will aid the discovery of novel therapeutics, new combination strategies and a strategy to enhance the efficacy of current chemotherapeutics. It has been hypothesized that cancer stem cells (CSCs) may be the initiating factor of resistance. We have previously identified and characterized an aldehyde dehydrogenase 1 CSC subpopulation in cisplatin resistant NSCLC. BBI608 is a small molecule STAT3 inhibitor known to suppress cancer relapse, progression and metastasis. Here, we show that BBI608 can inhibit stemness gene expression, deplete CSCs and overcome cisplatin resistance in NSCLC.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/farmacologia , Benzofuranos/farmacologia , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Cisplatino/farmacologia , Neoplasias Pulmonares/tratamento farmacológico , Naftoquinonas/farmacologia , Células-Tronco Neoplásicas/efeitos dos fármacos , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Apoptose/efeitos dos fármacos , Benzofuranos/uso terapêutico , Carcinoma Pulmonar de Células não Pequenas/patologia , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Cisplatino/uso terapêutico , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Humanos , Neoplasias Pulmonares/patologia , Naftoquinonas/uso terapêutico , Células-Tronco Neoplásicas/patologia , Fator de Transcrição STAT3/antagonistas & inibidores
10.
Sci Rep ; 8(1): 1652, 2018 01 26.
Artigo em Inglês | MEDLINE | ID: mdl-29374181

RESUMO

The PI3K-mTOR pathway is involved in regulating all hallmarks of cancer, and is often dysregulated in NSCLC, making it an attractive therapeutic target in this setting. Acquired resistance to PI3K-mTOR inhibition is a major hurdle to overcome in the success of PI3K-mTOR targeted agents. H460, A549, and H1975 resistant cells were generated by prolonged treatment in culture with Apitolisib (GDC-0980), a dual PI3K-mTOR inhibitor over a period of several months, from age-matched parent cells. Resistance was deemed to have developed when a log fold difference in IC50 had been achieved. Resistant cell lines also exhibited resistance to another widely investigated PI3K-mTOR dual inhibitor; Dactolisib (BEZ235). Cell lines were characterised at the level of mRNA (expression array profiling expression of >150 genes), miRNA (expression array profiling of 2100 miRNAs), protein (bottoms-up label-free mass spectrometry) and phosphoprotein (expression array profiling of 84 phospho/total proteins). Key alterations were validated by qPCR and Western blot. H1975 cells were initially most sensitive to Apitolisib (GDC-0980), but developed resistance more quickly than the other cell lines, perhaps due to increased selective pressure from the impressive initial effect. In-depth molecular profiling suggested epithelial-mesenchymal transition (EMT) may play a role in resistance to PI3K-mTOR dual inhibition in NSCLC.


Assuntos
Antineoplásicos/metabolismo , Carcinoma Pulmonar de Células não Pequenas , Linhagem Celular Tumoral , Resistência a Medicamentos , Fosfatidilinositol 3-Quinase/metabolismo , Serina-Treonina Quinases TOR/metabolismo , Western Blotting , Compostos Bicíclicos Heterocíclicos com Pontes/metabolismo , Perfilação da Expressão Gênica , Humanos , Imidazóis/metabolismo , Concentração Inibidora 50 , Proteoma/análise , Pirimidinas/metabolismo , Quinolinas/metabolismo , Reação em Cadeia da Polimerase em Tempo Real
11.
Oncotarget ; 8(42): 72544-72563, 2017 Sep 22.
Artigo em Inglês | MEDLINE | ID: mdl-29069808

RESUMO

Non-small cell lung cancer (NSCLC) accounts for a large proportion of cancer deaths and is characterized by low treatment response rates and poor overall prognosis. In the absence of specific treatable mutations, cisplatin-based chemotherapy plays an important role in the treatment of this disease. Unfortunately, the development of resistance has become a major therapeutic challenge in the use of this cytotoxic drug. Elucidating the mechanisms underlying this resistance phenotype, may result in the development of novel agents that enhance sensitivity to cisplatin in lung cancer patients. In this study, targeting the cancer stem cell activity of aldehyde dehydrogenase 1 (ALDH1) was investigated as a strategy to overcome chemoresistance in NSCLC. Tumors from NSCLC patients showed an increase in their profile of pluripotent stemness genes. Cisplatin exposure induced the emergence or expansion of an ALDH1-positive subpopulation in cisplatin sensitive and resistant NSCLC cell lines, respectively, further enhancing cisplatin resistance. Using the Aldefluor assay and FACS analysis, ALDH1 subpopulations were isolated and evaluated in terms of stem cell characteristics. Only ALDH1-positive cells exhibited asymmetric division, cisplatin resistance and increased expression of stem cell factors in vitro. Xenograft studies in NOD/SCID mice demonstrated efficient tumorigenesis from low cell numbers of ALDH1-positive and ALDH1-negative subpopulations. Targeting ALDH1 with Diethylaminobenzaldehyde (DEAB) and Disulfiram, significantly re-sensitized resistant lung cancer cells to the cytotoxic effects of cisplatin. Our data demonstrate the existence of a lung CSC population and suggest a role for targeting ALDH1 as a potential therapeutic strategy in re-sensitizing NSCLC cells to the cytotoxic effects of cisplatin.

12.
PLoS One ; 12(9): e0184922, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28945807

RESUMO

Lung cancer is the leading cause of cancer-related deaths. Most patients develop resistance to platinum within several months of treatment. We investigated whether triggering lysosomal membrane permeabilization (LMP) or suppressing autophagy can restore cisplatin susceptibility in lung cancer with acquired chemoresistance. Cisplatin IC50 in A549Pt (parental) and A549cisR (cisplatin resistant) cells was 13 µM and 47 µM, respectively. Following cisplatin exposure, A549cisR cells failed to elicit an apoptotic response. This was manifested by diminished Annexin-V staining, caspase 3 and 9, BAX and BAK activation in resistant but not in parental cells. Chloroquine preferentially promoted LMP in A549cisR cells, revealed by leakage of FITC-dextran into the cytosol as detected by immunofluorescence microscopy. This was confirmed by increased cytosolic cathepsin D signal on Immunoblot. Cell viability of cisplatin-treated A549cisR cells was decreased when co-treated with chloroquine, corresponding to a combination index below 0.8, suggesting synergism between the two drugs. Notably, chloroquine activated the mitochondrial cell death pathway as indicated by increase in caspase 9 activity. Interestingly, inhibition of lysosomal proteases using E64 conferred cytoprotection against cisplatin and chloroquine co-treatment, suggesting that chloroquine-induced cell death occurred in a cathepsin-mediated mechanism. Likewise, blockage of caspases partially rescued A549cisR cells against the cytotoxicity of cisplatin and chloroquine combination. Cisplatin promoted a dose-dependent autophagic flux induction preferentially in A549cisR cells, as evidenced by a surge in LC3-II/α-tubulin following pre-treatment with E64 and increase in p62 degradation. Compared to untreated cells, cisplatin induced an increase in cyto-ID-loaded autophagosomes in A549cisR cells that was further amplified by chloroquine, pointing toward autophagic flux activation by cisplatin. Interestingly, this effect was less pronounced in A549Pt cells. Blocking autophagy by ATG5 depletion using siRNA markedly enhances susceptibility to cisplatin in A549cisR cells. Taken together, our results underscore the utility of targeting lysosomal function in overcoming acquired cisplatin refractoriness in lung cancer.


Assuntos
Antineoplásicos/uso terapêutico , Autofagia/fisiologia , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Cisplatino/uso terapêutico , Neoplasias Pulmonares/tratamento farmacológico , Lisossomos/fisiologia , Células A549 , Apoptose/efeitos dos fármacos , Apoptose/fisiologia , Autofagia/efeitos dos fármacos , Cloroquina/farmacologia , Resistencia a Medicamentos Antineoplásicos , Humanos , Membranas Intracelulares/efeitos dos fármacos , Membranas Intracelulares/fisiologia , Lisossomos/efeitos dos fármacos , Microscopia de Fluorescência
13.
J Am Chem Soc ; 139(40): 14302-14314, 2017 10 11.
Artigo em Inglês | MEDLINE | ID: mdl-28948792

RESUMO

Seven rhenium(I) complexes of the general formula fac-[Re(CO)3(NN)(OH2)]+ where NN = 2,2'-bipyridine (8), 4,4'-dimethyl-2,2'-bipyridine (9), 4,4'-dimethoxy-2,2'-bipyridine (10), dimethyl 2,2'-bipyridine-4,4'-dicarboxylate (11), 1,10-phenanthroline (12), 2,9-dimethyl-1,10-phenanthroline (13), or 4,7-diphenyl-1,10-phenanthroline (14), were synthesized and characterized by 1H NMR spectroscopy, IR spectroscopy, mass spectrometry, and X-ray crystallography. With the exception of 11, all complexes exhibited 50% growth inhibitory concentration (IC50) values that were less than 20 µM in HeLa cells, indicating that these compounds represent a new potential class of anticancer agents. Complexes 9, 10, and 13 were as effective in cisplatin-resistant cells as wild-type cells, signifying that they circumvent cisplatin resistance. The mechanism of action of the most potent complex, 13, was explored further by leveraging its intrinsic luminescence properties to determine its intracellular localization. These studies indicated that 13 induces cytoplasmic vacuolization that is lysosomal in nature. Additional in vitro assays indicated that 13 induces cell death without causing an increase in intracellular reactive oxygen species or depolarization of the mitochondrial membrane potential. Further studies revealed that the mode of cell death does not fall into one of the canonical categories such as apoptosis, necrosis, paraptosis, and autophagy, suggesting that a novel mode of action may be operative for this class of rhenium compounds. The in vivo biodistribution and metabolism of complex 13 and its 99mTc analogue 13* were also evaluated in naïve mice. Complexes 13 and 13* exhibited comparable biodistribution profiles with both hepatic and renal excretion. High-performance liquid chromatography inductively coupled plasma mass-spectrometry (HPLC-ICP-MS) analysis of mouse blood plasma and urine postadministration showed considerable metabolic stability of 13, rendering this potent complex suitable for in vivo applications. These studies have shown the biological properties of this class of compounds and demonstrated their potential as promising theranostic anticancer agents that can circumvent cisplatin resistance.


Assuntos
Antineoplásicos/química , Antineoplásicos/farmacologia , Complexos de Coordenação/química , Complexos de Coordenação/farmacologia , Neoplasias/tratamento farmacológico , Rênio/química , Rênio/farmacologia , Animais , Antineoplásicos/farmacocinética , Ciclo Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Complexos de Coordenação/farmacocinética , Cristalografia por Raios X , Células HeLa , Humanos , Camundongos Endogâmicos C57BL , Modelos Moleculares , Neoplasias/metabolismo , Neoplasias/patologia , Espécies Reativas de Oxigênio/metabolismo , Rênio/farmacocinética , Distribuição Tecidual
14.
Sci Rep ; 6: 37052, 2016 11 15.
Artigo em Inglês | MEDLINE | ID: mdl-27845389

RESUMO

Hepatocellular carcinoma (HCC) is refractory to chemotherapies, necessitating novel effective agents. The lysosome inhibitor Bafilomycin A1 (BafA1) at high concentrations displays cytotoxicity in a variety of cancers. Here we show that BafA1 at nanomolar concentrations suppresses HCC cell growth in both 2 dimensional (2D) and 3D cultures. BafA1 induced cell cycle arrest in the G1 phase and triggered Cyclin D1 turnover in HCC cells in a dual-specificity tyrosine phosphorylation-regulated kinase 1B (DYRK1B) dependent manner. Notably, BafA1 induced caspase-independent cell death in HCC cells by impairing autophagy flux as demonstrated by elevated LC3 conversion and p62/SQSTM1 levels. Moreover, genetic ablation of LC3 significantly attenuated BafA1-induced cytotoxicity of HCC cells. We further demonstrate that pharmacological down-regulation or genetic depletion of p38 MAPK decreased BafA1-induced cell death via abolishment of BafA1-induced upregulation of Puma. Notably, knockdown of Puma impaired BafA1-induced HCC cell death, and overexpression of Puma enhanced BafA1-mediated HCC cell death, suggesting a role for Puma in BafA1-mediated cytotoxicity. Interestingly, pharmacological inhibition of JNK with SP600125 enhanced BafA1-mediated cytotoxicity both in vitro and in xenografts derived from HCC cells. Taken together, our data suggest that BafA1 may offer potential as an effective therapy for HCC.


Assuntos
Autofagia/efeitos dos fármacos , Carcinoma Hepatocelular , Caspases , Neoplasias Hepáticas , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Macrolídeos/farmacologia , Proteínas de Neoplasias , Animais , Autofagia/genética , Carcinoma Hepatocelular/tratamento farmacológico , Carcinoma Hepatocelular/genética , Carcinoma Hepatocelular/metabolismo , Carcinoma Hepatocelular/patologia , Caspases/genética , Caspases/metabolismo , Feminino , Células Hep G2 , Humanos , Neoplasias Hepáticas/tratamento farmacológico , Neoplasias Hepáticas/genética , Neoplasias Hepáticas/metabolismo , Neoplasias Hepáticas/patologia , Sistema de Sinalização das MAP Quinases/genética , Camundongos , Camundongos Nus , Proteínas de Neoplasias/genética , Proteínas de Neoplasias/metabolismo , Ensaios Antitumorais Modelo de Xenoenxerto
15.
Cancer Lett ; 372(2): 147-56, 2016 Mar 28.
Artigo em Inglês | MEDLINE | ID: mdl-26797015

RESUMO

In the absence of specific treatable mutations, platinum-based chemotherapy remains the gold standard of treatment for lung cancer patients. However, 5-year survival rates remain poor due to the development of resistance and eventual relapse. Resistance to conventional cytotoxic therapies presents a significant clinical challenge in the treatment of this disease. The cancer stem cell (CSC) hypothesis suggests that tumors are arranged in a hierarchical structure, with the presence of a small subset of stem-like cells that are responsible for tumor initiation and growth. This CSC population has a number of key properties such as the ability to asymmetrically divide, differentiate and self-renew, in addition to having increased intrinsic resistance to therapy. While cytotoxic chemotherapy kills the bulk of tumor cells, CSCs are spared and have the ability to recapitulate the heterogenic tumor mass. The identification of lung CSCs and their role in tumor biology and treatment resistance may lead to innovative targeted therapies that may ultimately improve clinical outcomes in lung cancer patients. This review will focus on lung CSC markers, their role in resistance and their relevance as targets for future therapies.


Assuntos
Antineoplásicos/uso terapêutico , Resistencia a Medicamentos Antineoplásicos , Neoplasias Pulmonares/tratamento farmacológico , Células-Tronco Neoplásicas/efeitos dos fármacos , Células da Side Population/efeitos dos fármacos , Animais , Biomarcadores Tumorais/genética , Biomarcadores Tumorais/metabolismo , Diferenciação Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Resistencia a Medicamentos Antineoplásicos/genética , Humanos , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/metabolismo , Neoplasias Pulmonares/patologia , Terapia de Alvo Molecular , Células-Tronco Neoplásicas/metabolismo , Células-Tronco Neoplásicas/patologia , Fenótipo , Células da Side Population/metabolismo , Células da Side Population/patologia , Transdução de Sinais/efeitos dos fármacos
16.
Int J Oncol ; 48(3): 1290-6, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26780987

RESUMO

Malignant pleural mesothelioma (MPM) is a rare aggressive cancer of the pleura. Asbestos exposure (through inhalation) is the most well established risk factor for mesothelioma. The current standard of care for patients suffering from MPM is a combination of cisplatin and pemetrexed (or alternatively cisplatin and raltitrexed). Most patients, however, die within 24 months of diagnosis. New therapies are therefore urgently required for this disease. Lysine acetyltransferases (KATs) including KAT5 have been linked with the development of cisplatin resistance. This gene may therefore be altered in MPM and could represent a novel candidate target for intervention. Using RT-PCR screening the expression of all known KAT5 variants was found to be markedly increased in malignant tumors compared to benign pleura. When separated according to histological subtype, KAT5 was significantly overexpressed in both the sarcomatoid and biphasic subgroups for all transcript variants. A panel of MPM cell lines including the normal pleural cells LP9 and Met5A was screened for expression of KAT5 variants. Treatment of cells with a small molecule inhibitor of KAT5 (MG-149) caused significant inhibition of cellular proliferation (p<0.0001), induction of apoptosis and was accompanied by significant induction of pro-inflammatory cytokines/chemokines.


Assuntos
Regulação Neoplásica da Expressão Gênica , Histona Acetiltransferases/metabolismo , Neoplasias Pulmonares/metabolismo , Mesotelioma/metabolismo , Neoplasias Pleurais/metabolismo , Apoptose , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Separação Celular , Quimiocinas/metabolismo , Citocinas/metabolismo , Epitélio/metabolismo , Humanos , Inflamação , Lisina Acetiltransferase 5 , Fatores de Risco
17.
Pharmacol Ther ; 158: 71-90, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26706243

RESUMO

Lung cancer is the leading cause of cancer mortality worldwide. Despite advances in anti-cancer therapies such as chemotherapy, radiotherapy and targeted therapies, five-year survival rates remain poor (<15%). Inherent and acquired resistance has been identified as a key factor in reducing the efficacy of current cytotoxic therapies in the management of non-small cell lung cancer (NSCLC). There is growing evidence suggesting that cancer stem cells (CSCs) play a critical role in tumor progression, metastasis and drug resistance. Similar to normal tissue stem cells, CSCs exhibit significant phenotypic and functional heterogeneity. While CSCs have been reported in a wide spectrum of human tumors, the biology of CSCs in NSCLC remain elusive. Current anti-cancer therapies fail to eradicate CSC clones and instead, favor the expansion of the CSC pool and select for resistant CSC clones thereby resulting in treatment resistance and subsequent relapse in these patients. The identification of CSC-specific marker subsets and the targeted therapeutic destruction of CSCs remains a significant challenge. Strategies aimed at efficient targeting of CSCs are becoming increasingly important for monitoring the progress of cancer therapy and for evaluating new therapeutic approaches. This review focuses on the current knowledge of cancer stem cell markers in treatment-resistant lung cancer cells and the signaling cascades activated by these cells to maintain their stem-like properties. Recent progress in CSC-targeted drug development and the current status of novel agents in clinical trials are also reviewed.


Assuntos
Antineoplásicos/farmacologia , Antineoplásicos/uso terapêutico , Biomarcadores Tumorais/metabolismo , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Neoplasias Pulmonares/tratamento farmacológico , Células-Tronco Neoplásicas/efeitos dos fármacos , Transdução de Sinais/efeitos dos fármacos , Animais , Humanos , Células-Tronco Neoplásicas/metabolismo
18.
Epigenomics ; 7(6): 897-910, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26479311

RESUMO

AIMS: To evaluate the potential therapeutic utility of histone deacetylase inhibitors (HDACi) in targeting VEGF receptors in non-small-cell lung cancer. MATERIALS & METHODS: Non-small-cell lung cancer cells were screened for the VEGF receptors at the mRNA and protein levels, while cellular responses to various HDACi were examined. RESULTS: Significant effects on the regulation of the VEGF receptors were observed in response to HDACi. These were associated with decreased secretion of VEGF, decreased cellular proliferation and increased apoptosis which could not be rescued by addition of exogenous recombinant VEGF. Direct remodeling of the VEGFR1 and VEGFR2 promoters was observed. In contrast, HDACi treatments resulted in significant downregulation of the Neuropilin receptors. CONCLUSION: Epigenetic targeting of the Neuropilin receptors may offer an effective treatment for lung cancer patients in the clinical setting.


Assuntos
Carcinoma Pulmonar de Células não Pequenas/genética , Neoplasias Pulmonares/genética , Fator A de Crescimento do Endotélio Vascular/genética , Acetilação , Apoptose/efeitos dos fármacos , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Carcinoma Pulmonar de Células não Pequenas/metabolismo , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/genética , Montagem e Desmontagem da Cromatina/genética , Epigênese Genética/efeitos dos fármacos , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Inibidores de Histona Desacetilases/farmacologia , Histonas/metabolismo , Humanos , Ácidos Hidroxâmicos/farmacologia , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/metabolismo , Terapia de Alvo Molecular , Receptores de Fatores de Crescimento do Endotélio Vascular/genética , Receptores de Fatores de Crescimento do Endotélio Vascular/metabolismo , Fator A de Crescimento do Endotélio Vascular/metabolismo , Vorinostat
19.
Mol Cancer ; 14: 45, 2015 Feb 20.
Artigo em Inglês | MEDLINE | ID: mdl-25889301

RESUMO

BACKGROUND: The VEGF pathway has become an important therapeutic target in lung cancer, where VEGF has long been established as a potent pro-angiogenic growth factor expressed by many types of tumors. While Bevacizumab (Avastin) has proven successful in increasing the objective tumor response rate and in prolonging progression and overall survival in patients with NSCLC, the survival benefit is however relatively short and the majority of patients eventually relapse. The current use of tyrosine kinase inhibitors alone and in combination with chemotherapy has been underwhelming, highlighting an urgent need for new targeted therapies. In this study, we examined the mechanisms of VEGF-mediated survival in NSCLC cells and the role of the Neuropilin receptors in this process. METHODS: NSCLC cells were screened for expression of VEGF and its receptors. The effects of recombinant VEGF and its blockade on lung tumor cell proliferation and cell cycle were examined. Phosphorylation of Akt and Erk1/2 proteins was examined by high content analysis and confocal microscopy. The effects of silencing VEGF on cell proliferation and survival signaling were also assessed. A Neuropilin-1 stable-transfected cell line was generated. Cell growth characteristics in addition to pAkt and pErk1/2 signaling were studied in response to VEGF and its blockade. Tumor growth studies were carried out in nude mice following subcutaneous injection of NP1 over-expressing cells. RESULTS: Inhibition of the VEGF pathway with anti-VEGF and anti-VEGFR-2 antibodies or siRNA to VEGF, NP1 and NP2 resulted in growth inhibition of NP1 positive tumor cell lines associated with down-regulation of PI3K and MAPK kinase signaling. Stable transfection of NP1 negative cells with NP1 induced proliferation in vitro, which was further enhanced by exogenous VEGF. In vivo, NP1 over-expressing cells significantly increased tumor growth in xenografts compared to controls. CONCLUSIONS: Our data demonstrate that VEGF is an autocrine growth factor in NSCLC signaling, at least in part, through NP1. Targeting this VEGF receptor may offer potential as a novel therapeutic approach and also support the evaluation of the role of NP1 as a biomarker predicting sensitivity or resistance to VEGF and VEGFR-targeted therapies in the clinical arena.


Assuntos
Proteína C-Reativa/genética , Carcinoma Pulmonar de Células não Pequenas/genética , Neoplasias Pulmonares/genética , Proteínas do Tecido Nervoso/genética , Transdução de Sinais/genética , Fator A de Crescimento do Endotélio Vascular/genética , Animais , Linhagem Celular Tumoral , Proliferação de Células/genética , Regulação para Baixo/genética , Feminino , Humanos , Sistema de Sinalização das MAP Quinases/genética , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Quinases de Proteína Quinase Ativadas por Mitógeno/genética , Fosfatidilinositol 3-Quinases/genética , Receptores de Fatores de Crescimento do Endotélio Vascular/genética
20.
Cancer Treat Rev ; 41(2): 160-9, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-25592062

RESUMO

One of the major challenges in the treatment of lung cancer is the development of drug resistance. This represents a major obstacle in the treatment of patients, limiting the efficacy of both conventional chemotherapy and biological therapies. Deciphering the mechanisms of resistance is critical to further understanding the multifactorial pathways involved, and in developing more specific targeted treatments. To date, numerous studies have reported the potential role of microRNAs (miRNAs) in resistance to various cancer treatments. MicroRNAs are a family of small non-coding RNAs that regulate gene expression by sequence-specific targeting of mRNAs causing translational repression or mRNA degradation. More than 1200 validated human miRNAs have been identified to date. While as little as one miRNA can regulate hundreds of targets, a single target can also be affected by multiple miRNAs. Evidence suggests that dysregulation of specific miRNAs may be involved in the acquisition of resistance to a number of cancer treatments, thereby modulating the sensitivity of cancer cells to such therapies. Therefore, targeting miRNAs may be an attractive strategy for developing novel and more effective individualized therapies, improving drug efficiency, and for predicting patient response to different treatments. In this review, we provide an overview on the role of miRNAs in resistance to current lung cancer therapies and novel biological agents.


Assuntos
Antineoplásicos/farmacologia , Resistencia a Medicamentos Antineoplásicos , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/genética , MicroRNAs/metabolismo , Inibidores da Angiogênese/farmacologia , Antimetabólitos Antineoplásicos/farmacologia , Antineoplásicos/uso terapêutico , Apoptose/efeitos dos fármacos , Apoptose/genética , Receptores ErbB/antagonistas & inibidores , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , Neoplasias Pulmonares/mortalidade , Compostos de Platina/farmacologia , Tolerância a Radiação , Radioterapia Adjuvante , Ligante Indutor de Apoptose Relacionado a TNF/genética , Ligante Indutor de Apoptose Relacionado a TNF/metabolismo , Taxoides/farmacologia
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