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1.
Oncogene ; 36(42): 5852-5860, 2017 10 19.
Artigo em Inglês | MEDLINE | ID: mdl-28628118

RESUMO

Mitogen-activated protein kinase kinase 3 (MKK3) is a dual threonine/tyrosine protein kinase that regulates inflammation, proliferation and apoptosis through specific phosphorylation and activation of the p38 mitogen-activated protein kinase. However, the role of MKK3 beyond p38-signaling remains elusive. Recently, we reported a protein-protein interaction (PPI) network of cancer-associated genes, termed OncoPPi, as a resource for the scientific community to generate new biological models. Analysis of the OncoPPi connectivity identified MKK3 as one of the major hub proteins in the network. Here, we show that MKK3 interacts with a large number of proteins critical for cell growth and metabolism, including the major oncogenic driver MYC. Multiple complementary approaches were used to demonstrate the direct interaction of MKK3 with MYC in vitro and in vivo. Computational modeling and experimental studies mapped the interaction interface to the MYC helix-loop-helix domain and a novel 15-residue MYC-binding motif in MKK3 (MBM). The MBM in MKK3 is distinct from the known binding sites for p38 or upstream kinases. Functionally, MKK3 stabilized MYC protein, enhanced its transcriptional activity and increased expression of MYC-regulated genes. The defined MBM peptide mimicked the MKK3 effect in promoting MYC activity. Together, the exploration of OncoPPi led to a new biological model in which MKK3 operates by two distinct mechanisms in cellular regulation through its phosphorylation of p38 and its activation of MYC through PPI.


Assuntos
Proteínas de Ligação a DNA/metabolismo , Neoplasias Pulmonares/metabolismo , MAP Quinase Quinase 3/metabolismo , Mapas de Interação de Proteínas , Fatores de Transcrição/metabolismo , Linhagem Celular Tumoral , Proteínas de Ligação a DNA/química , Proteínas de Ligação a DNA/genética , Bases de Dados de Proteínas , Ativação Enzimática , Humanos , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/patologia , MAP Quinase Quinase 3/genética , Fosforilação , Conformação Proteica , Transdução de Sinais/genética , Fatores de Transcrição/química , Fatores de Transcrição/genética , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismo
2.
Oncogene ; 36(27): 3797-3806, 2017 07 06.
Artigo em Inglês | MEDLINE | ID: mdl-28218905

RESUMO

Metastases remain the major cause of death from cancer. Recent molecular advances have highlighted the importance of metabolic alterations in cancer cells, including the Warburg effect that describes an increased glycolysis in cancer cells. However, how this altered metabolism contributes to tumour metastasis remains elusive. Here, we report that phosphorylation-induced activation of lactate dehydrogenase A (LDHA), an enzyme that catalyses the interconversion of pyruvate and lactate, promotes cancer cell invasion, anoikis resistance and tumour metastasis. We demonstrate that LDHA is phosphorylated at tyrosine 10 by upstream kinases, HER2 and Src. Targeting HER2 or Src attenuated LDH activity as well as invasive potential in head and neck cancer and breast cancer cells. Inhibition of LDH activity by small hairpin ribonucleic acid or expression of phospho-deficient LDHA Y10F sensitized the cancer cells to anoikis induction and resulted in attenuated cell invasion and elevated reactive oxygen species, whereas such phenotypes were reversed by its product lactate or antioxidant N-acetylcysteine, suggesting that Y10 phosphorylation-mediated LDHA activity promotes cancer cell invasion and anoikis resistance through redox homeostasis. In addition, LDHA knockdown or LDHA Y10F rescue expression in human cancer cells resulted in decreased tumour metastasis in xenograft mice. Furthermore, LDHA phosphorylation at Y10 positively correlated with progression of metastatic breast cancer in clinical patient tumour samples. Our findings demonstrate that LDHA phosphorylation and activation provide pro-invasive, anti-anoikis and pro-metastatic advantages to cancer cells, suggesting that Y10 phosphorylation of LDHA may represent a promising therapeutic target and a prognostic marker for metastatic human cancers.


Assuntos
Neoplasias da Mama/enzimologia , L-Lactato Desidrogenase/metabolismo , Processamento de Proteína Pós-Traducional , Animais , Anoikis/efeitos dos fármacos , Antineoplásicos/farmacologia , Benzodioxóis/farmacologia , Neoplasias da Mama/patologia , Linhagem Celular Tumoral , Proliferação de Células , Ativação Enzimática , Feminino , Humanos , Isoenzimas/genética , Isoenzimas/metabolismo , L-Lactato Desidrogenase/genética , Lactato Desidrogenase 5 , Metástase Linfática , Camundongos Nus , Invasividade Neoplásica , Transplante de Neoplasias , Fosforilação , Quinazolinas/farmacologia , Espécies Reativas de Oxigênio , Receptor ErbB-2/metabolismo , Quinases da Família src/metabolismo
3.
Oncogene ; 36(2): 254-262, 2017 01 12.
Artigo em Inglês | MEDLINE | ID: mdl-27270429

RESUMO

The oxidative pentose phosphate pathway (PPP) is crucial for cancer cell metabolism and tumor growth. We recently reported that targeting a key oxidative PPP enzyme, 6-phosphogluconate dehydrogenase (6PGD), using our novel small-molecule 6PGD inhibitors Physcion and its derivative S3, shows anticancer effects. Notably, humans with genetic deficiency of either 6PGD or another oxidative PPP enzyme, glucose-6-phosphate dehydrogenase, exhibit non-immune hemolytic anemia upon exposure to aspirin and various antimalarial drugs. Inspired by these clinical observations, we examined the anticancer potential of combined treatment with 6PGD inhibitors and antimalarial drugs. We found that stable knockdown of 6PGD sensitizes leukemia cells to antimalarial agent dihydroartemisinin (DHA). Combined treatment with DHA and Physcion activates AMP-activated protein kinase, leading to synergistic inhibition of human leukemia cell viability. Moreover, our combined therapy synergistically attenuates tumor growth in xenograft nude mice injected with human K562 leukemia cells and cell viability of primary leukemia cells from human patients, but shows minimal toxicity to normal hematopoietic cells in mice as well as red blood cells and mononucleocytes from healthy human donors. Our findings reveal the potential for combined therapy using optimized doses of Physcion and DHA as a novel antileukemia treatment without inducing hemolysis.


Assuntos
Antimaláricos/administração & dosagem , Protocolos de Quimioterapia Combinada Antineoplásica/administração & dosagem , Emodina/análogos & derivados , Leucemia/tratamento farmacológico , Via de Pentose Fosfato/efeitos dos fármacos , Fosfogluconato Desidrogenase/antagonistas & inibidores , Animais , Antimaláricos/farmacologia , Protocolos de Quimioterapia Combinada Antineoplásica/farmacologia , Artemisininas/administração & dosagem , Artemisininas/farmacologia , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Sinergismo Farmacológico , Emodina/administração & dosagem , Emodina/farmacologia , Feminino , Humanos , Células K562 , Leucemia/enzimologia , Camundongos , Camundongos Nus , Ensaios Antitumorais Modelo de Xenoenxerto
4.
Oncogene ; 35(41): 5412-5421, 2016 10 13.
Artigo em Inglês | MEDLINE | ID: mdl-27041561

RESUMO

Metastasis is responsible for >90% of cancer-related deaths. Complex signaling in cancer cells orchestrates the progression from a primary to a metastatic cancer. However, the mechanisms of these cellular changes remain elusive. We previously demonstrated that p90 ribosomal S6 kinase 2 (RSK2) promotes tumor metastasis. Here we investigated the role of RSK2 in the regulation of microtubule dynamics and its potential implication in cancer cell invasion and tumor metastasis. Stable knockdown of RSK2 disrupted microtubule stability and decreased phosphorylation of stathmin, a microtubule-destabilizing protein, at serine 16 in metastatic human cancer cells. We found that RSK2 directly binds and phosphorylates stathmin at the leading edge of cancer cells. Phosphorylation of stathmin by RSK2 reduced stathmin-mediated microtubule depolymerization. Moreover, overexpression of phospho-mimetic mutant stathmin S16D significantly rescued the decreased invasive and metastatic potential mediated by RSK2 knockdown in vitro and in vivo. Furthermore, stathmin phosphorylation positively correlated with RSK2 expression and metastatic cancer progression in primary patient tumor samples. Our finding demonstrates that RSK2 directly phosphorylates stathmin and regulates microtubule polymerization to provide a pro-invasive and pro-metastatic advantage to cancer cells. Therefore, the RSK2-stathmin pathway represents a promising therapeutic target and a prognostic marker for metastatic human cancers.


Assuntos
Neoplasias Pulmonares/genética , Metástase Neoplásica/genética , Proteínas Quinases S6 Ribossômicas 90-kDa/genética , Estatmina/genética , Células A549 , Movimento Celular/genética , Técnicas de Silenciamento de Genes , Humanos , Neoplasias Pulmonares/patologia , Microtúbulos/genética , Microtúbulos/patologia , Invasividade Neoplásica/genética , Invasividade Neoplásica/patologia , Metástase Neoplásica/patologia , Fosforilação , Proteínas Quinases S6 Ribossômicas 90-kDa/metabolismo , Transdução de Sinais , Estatmina/metabolismo
5.
Oncogene ; 35(5): 642-50, 2016 Feb 04.
Artigo em Inglês | MEDLINE | ID: mdl-25893295

RESUMO

Cancer cells feature increased de novo lipogenesis. Sterol regulatory element-binding protein 1 (SREBP1), when presented in its mature form (mSREBP1), enhances lipogenesis by increasing transcription of several of its target genes. Mammalian target of rapamycin (mTOR) complexes, mTORC1 and mTORC2, are master regulators of cellular survival, growth and metabolism. A role for mTORC1 in the regulation of SREBP1 activity has been suggested; however, the connection between mTORC2 and SREBP1 has not been clearly established and hence is the focus of this study. mTOR kinase inhibitors (for example, INK128), which inhibit both mTORC1 and mTORC2, decreased mSREBP1 levels in various cancer cell lines. Knockdown of rictor, but not raptor, also decreased mSREBP1. Consistently, reduced mSREBP1 levels were detected in cells deficient in rictor or Sin1 compared with parent or rictor-deficient cells with re-expression of ectopic rictor. Hence it is mTORC2 inhibition that causes mSREBP1 reduction. As a result, expression of the mSREBP1 target genes acetyl-CoA carboxylase and fatty-acid synthase was suppressed, along with suppressed lipogenesis in cells exposed to INK128. Moreover, mSREBP1 stability was reduced in cells treated with INK128 or rictor knockdown. Inhibition of proteasome, GSK3 or the E3 ubiquitin ligase, FBXW7, prevented mSREBP1 reduction induced by mTORC2 inhibition. Thus mTORC2 inhibition clearly facilitates GSK3-dependent, FBXW7-mediated mSREBP1 degradation, leading to mSREBP1 reduction. Accordingly, we conclude that mTORC2 positively regulates mSREBP1 stability and lipogenesis. Our findings reveal a novel biological function of mTORC2 in the regulation of lipogenesis and warrant further study in this direction.


Assuntos
Proteínas de Ciclo Celular/metabolismo , Proteínas F-Box/metabolismo , Quinase 3 da Glicogênio Sintase/metabolismo , Complexos Multiproteicos/antagonistas & inibidores , Proteína de Ligação a Elemento Regulador de Esterol 1/metabolismo , Serina-Treonina Quinases TOR/antagonistas & inibidores , Ubiquitina-Proteína Ligases/metabolismo , Proteínas de Ciclo Celular/genética , Linhagem Celular Tumoral , Inibidores Enzimáticos/farmacologia , Proteínas F-Box/genética , Proteína 7 com Repetições F-Box-WD , Técnicas de Silenciamento de Genes , Células HCT116 , Humanos , Indóis/farmacologia , Lipogênese , Maleimidas/farmacologia , Alvo Mecanístico do Complexo 2 de Rapamicina , Complexos Multiproteicos/metabolismo , Neoplasias/tratamento farmacológico , Neoplasias/metabolismo , Neoplasias/patologia , Serina-Treonina Quinases TOR/metabolismo , Transfecção , Ubiquitina-Proteína Ligases/genética
6.
Oncogene ; 35(4): 459-67, 2016 Jan 28.
Artigo em Inglês | MEDLINE | ID: mdl-25867065

RESUMO

Inhibition of B-Raf/MEK/ERK signaling is an effective therapeutic strategy against certain types of cancers such as melanoma and thyroid cancer. While demonstrated to be effective anticancer agents, B-Raf or MEK inhibitors have also been associated with early tumor progression and development of secondary neoplasms. The ligation of tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) with its receptor, death receptor 5 (DR5), leading to induction of apoptosis, offers a promising anticancer strategy. Importantly, this is also a natural immunosurveillance mechanism against cancer development. We previously demonstrated that activated B-Raf/MEK/ERK signaling positively regulates DR5 expression. Hence, our current work sought to address whether B-Raf/MEK/ERK inhibition and the consequent suppression of DR5 expression impede cancer cell response to DR5 activation-induced apoptosis and activated immune cell-induced killing. We found that both B-Raf (for example, PLX4032) and MEK inhibitors (for example, AZD6244 and PD0325901) effectively inhibited ERK1/2 phosphorylation and reduced DR5 levels in both human thyroid cancer and melanoma cells. Similar to the observed effect of genetic knockdown of the B-Raf gene, pre-treatment of cancer cell lines with either B-Raf or MEK inhibitors attenuated or abolished cellular apoptotic response induced by TRAIL or the DR5 agonistic antibody AMG655 or cell killing by activated T cells. Our findings clearly show that inhibition of B-Raf/MEK/ERK signaling suppresses DR5 expression and impairs DR5 activation-induced apoptosis and T cell-mediated killing of cancer cells. These findings suggest a potential negative impact of B-Raf or MEK inhibition on TRAIL- or DR5-mediated anticancer therapy and on TRAIL/DR5-mediated immune-clearance of cancer cells.


Assuntos
Inibidores Enzimáticos/farmacologia , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , MAP Quinase Quinase Quinases/metabolismo , Proteínas Proto-Oncogênicas B-raf/antagonistas & inibidores , Receptores do Ligante Indutor de Apoptose Relacionado a TNF/metabolismo , Apoptose/efeitos dos fármacos , Benzimidazóis/farmacologia , Linhagem Celular Tumoral/efeitos dos fármacos , MAP Quinases Reguladas por Sinal Extracelular/antagonistas & inibidores , Humanos , Indóis/farmacologia , MAP Quinase Quinase Quinases/antagonistas & inibidores , Proteínas Proto-Oncogênicas B-raf/genética , Proteínas Proto-Oncogênicas B-raf/metabolismo , RNA Interferente Pequeno , Receptores do Ligante Indutor de Apoptose Relacionado a TNF/genética , Transdução de Sinais/efeitos dos fármacos , Sulfonamidas/farmacologia , Linfócitos T/efeitos dos fármacos , Linfócitos T/metabolismo , Ligante Indutor de Apoptose Relacionado a TNF/metabolismo , Vemurafenib
7.
Ann Oncol ; 26(8): 1741-8, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-25997818

RESUMO

BACKGROUND: This trial was designed to evaluate the activity and safety of ganetespib in combination with docetaxel in advanced non-small cell lung cancer (NSCLC) and to identify patient populations most likely to benefit from the combination. PATIENTS AND METHODS: Patients with one prior systemic therapy for advanced disease were eligible. Docetaxel (75 mg/m(2) on day 1) was administered alone or with ganetespib (150 mg/m(2) on days 1 and 15) every 3 weeks. The primary end points were progression-free survival (PFS) in two subgroups of the adenocarcinoma population: patients with elevated lactate dehydrogenase (eLDH) and mutated KRAS (mKRAS). RESULTS: Of 385 patients enrolled, 381 were treated. Early in the trial, increased hemoptysis and lack of efficacy were observed in nonadenocarcinoma patients (n = 71); therefore, only patients with adenocarcinoma histology were subsequently enrolled. Neutropenia was the most common grade ≥3 adverse event: 41% in the combination arm versus 42% in docetaxel alone. There was no improvement in PFS for the combination arm in the eLDH (N = 114, adjusted hazard ratio (HR) = 0.77, P = 0.1134) or mKRAS (N = 89, adjusted HR = 1.11, P = 0.3384) subgroups. In the intent-to-treat adenocarcinoma population, there was a trend in favor of the combination, with PFS (N = 253, adjusted HR = 0.82, P = 0.0784) and overall survival (OS) (adjusted HR = 0.84, P = 0.1139). Exploratory analyses showed significant benefit of the ganetespib combination in the prespecified subgroup of adenocarcinoma patients diagnosed with advanced disease >6 months before study entry (N = 177): PFS (adjusted HR = 0.74, P = 0.0417); OS (adjusted HR = 0.69, P = 0.0191). CONCLUSION: Advanced lung adenocarcinoma patients treated with ganetespib in combination with docetaxel had an acceptable safety profile. While the study's primary end points were not met, significant prolongation of PFS and OS was observed in patients >6 months from diagnosis of advanced disease, a subgroup chosen as the target population for the phase III study.


Assuntos
Adenocarcinoma/tratamento farmacológico , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Neoplasias Pulmonares/tratamento farmacológico , Adenocarcinoma/genética , Adenocarcinoma/metabolismo , Adenocarcinoma/patologia , Idoso , Carcinoma Pulmonar de Células não Pequenas/metabolismo , Carcinoma Pulmonar de Células não Pequenas/patologia , Intervalo Livre de Doença , Docetaxel , Feminino , Proteínas de Choque Térmico HSP90/antagonistas & inibidores , Humanos , L-Lactato Desidrogenase/metabolismo , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/metabolismo , Neoplasias Pulmonares/patologia , Masculino , Pessoa de Meia-Idade , Modelos de Riscos Proporcionais , Proteínas Proto-Oncogênicas p21(ras)/genética , Taxoides/administração & dosagem , Resultado do Tratamento , Triazóis/administração & dosagem
8.
Oncogene ; 34(19): 2538-45, 2015 May 07.
Artigo em Inglês | MEDLINE | ID: mdl-24975575

RESUMO

The cyclin-dependent kinase (CDK) inhibitor 1A, p21/Cip1, is a vital cell cycle regulator, dysregulation of which has been associated with a large number of human malignancies. One critical mechanism that controls p21 function is through its degradation, which allows the activation of its associated cell cycle-promoting kinases, CDK2 and CDK4. Thus delineating how p21 is stabilized and degraded will enhance our understanding of cell growth control and offer a basis for potential therapeutic interventions. Here we report a novel regulatory mechanism that controls the dynamic status of p21 through its interaction with Cdk5 and Abl enzyme substrate 1 (Cables1). Cables1 has a proposed role as a tumor suppressor. We found that upregulation of Cables1 protein was correlated with increased half-life of p21 protein, which was attributed to Cables1/p21 complex formation and supported by their co-localization in the nucleus. Mechanistically, Cables1 interferes with the proteasome (Prosome, Macropain) subunit alpha type 3 (PSMA3) binding to p21 and protects p21 from PSMA3-mediated proteasomal degradation. Moreover, silencing of p21 partially reverses the ability of Cables1 to induce cell death and inhibit cell proliferation. In further support of a potential pathophysiological role of Cables1, the expression level of Cables1 is tightly associated with p21 in both cancer cell lines and human lung cancer patient tumor samples. Together, these results suggest Cables1 as a novel p21 regulator through maintaining p21 stability and support the model that the tumor-suppressive function of Cables1 occurs at least in part through enhancing the tumor-suppressive activity of p21.


Assuntos
Proteínas de Transporte/metabolismo , Inibidor de Quinase Dependente de Ciclina p21/metabolismo , Ciclinas/metabolismo , Neoplasias Pulmonares/patologia , Fosfoproteínas/metabolismo , Proteínas Supressoras de Tumor/metabolismo , Apoptose/genética , Proteínas de Transporte/biossíntese , Proteínas de Transporte/genética , Linhagem Celular Tumoral , Proliferação de Células/genética , Quinase 2 Dependente de Ciclina/metabolismo , Quinase 4 Dependente de Ciclina/metabolismo , Inibidor de Quinase Dependente de Ciclina p21/genética , Ciclinas/biossíntese , Ciclinas/genética , Células HEK293 , Humanos , Neoplasias Pulmonares/genética , Fosfoproteínas/biossíntese , Fosfoproteínas/genética , Complexo de Endopeptidases do Proteassoma/metabolismo , Ligação Proteica , Proteólise , Interferência de RNA , RNA Interferente Pequeno , Proteínas Supressoras de Tumor/genética
9.
Cell Death Differ ; 21(7): 1160-9, 2014 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-24769731

RESUMO

Mcl-1 is a unique antiapoptotic Bcl2 family member with a short half-life due to its rapid turnover through ubiquitination. We discovered that Ku70, a DNA double-strand break repair protein, functions as a deubiquitinase to stabilize Mcl-1. Ku70 knockout in mouse embryonic fibroblast (MEF) cells or depletion from human lung cancer H1299 cells leads to the accumulation of polyubiquitinated Mcl-1 and a reduction in its half-life and protein expression. Conversely, expression of exogenous Ku70 in Ku70(-/-) MEF cells restores Mcl-1 expression. Subcellular fractionation indicates that Ku70 extensively colocalizes with Mcl-1 in mitochondria, endoplasmic reticulum and nucleus in H1299 cells. Ku70 directly interacts with Mcl-1 via its C terminus (that is, aa 536-609), which is required and sufficient for deubiquitination and stabilization of Mcl-1, leading to suppression of apoptosis. Purified Ku70 protein directly deubiquitinates Mcl-1 by removing K48-linked polyubiquitin chains. Ku70 knockdown not only promotes Mcl-1 turnover but also enhances antitumor efficacy of the BH3-mimetic ABT-737 in human lung cancer xenografts. These findings identify Ku70 as a novel Mcl-1 deubiquitinase that could be a potential target for cancer therapy by manipulating Mcl-1 deubiquitination.


Assuntos
Antígenos Nucleares/fisiologia , Apoptose , Proteínas de Ligação a DNA/fisiologia , Proteína de Sequência 1 de Leucemia de Células Mieloides/metabolismo , Ubiquitinação , Animais , Antineoplásicos/farmacologia , Compostos de Bifenilo/farmacologia , Sobrevivência Celular , Células HCT116 , Células HEK293 , Meia-Vida , Humanos , Autoantígeno Ku , Camundongos , Camundongos Nus , Nitrofenóis/farmacologia , Piperazinas/farmacologia , Domínios e Motivos de Interação entre Proteínas , Estabilidade Proteica , Transporte Proteico , Estaurosporina/farmacologia , Sulfonamidas/farmacologia , Ensaios Antitumorais Modelo de Xenoenxerto
10.
Br J Cancer ; 108(4): 762-5, 2013 Mar 05.
Artigo em Inglês | MEDLINE | ID: mdl-23322195

RESUMO

BACKGROUND: This phase 1 trial utilising a Bayesian continual reassessment method evaluated bortezomib and sunitinib to determine the maximum tolerated dose (MTD), dose-limiting toxicities (DLT), and recommended doses of the combination. METHODS: Patients with advanced solid organ malignancies were enrolled and received bortezomib weekly with sunitinib daily for 4 weeks, every 6 weeks. Initial doses were sunitinib 25 mg and bortezomib 1 mg m(-2). Cohort size and dose level estimation was performed utilising the Escalation with Overdose Control (EWOC) adaptive method. Seven dose levels were evaluated; initially, sunitinib was increased to a goal dose of 50 mg with fixed bortezomib, then bortezomib was increased. Efficacy assessment occurred after each cycle using RECIST criteria. RESULTS: Thirty patients were evaluable. During sunitinib escalation, DLTs of grade 4 thrombocytopenia (14%) and neutropenia (6%) at sunitinib 50 mg and bortezomib 1.3 mg m(-2) were seen. Subsequent experience showed tolerability and activity for sunitinib 37.5 mg and bortezomib 1.9 mg m(-2). Common grade 3/4 toxicities were neutropenia, thrombocytopenia, hypertension, and diarrhoea. The recommended doses for further study are bortezomib 1.9 mg m(-2) and sunitinib 37.5 mg. Four partial responses were seen. Stable disease >6 months was noted in an additional six patients. CONCLUSION: Bortezomib and sunitinib are well tolerated and have anticancer activity, particularly in thyroid cancer. A phase 2 study of this combination in thyroid cancer patients is planned.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Ácidos Borônicos/administração & dosagem , Indóis/administração & dosagem , Pirazinas/administração & dosagem , Pirróis/administração & dosagem , Adulto , Idoso , Idoso de 80 Anos ou mais , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Teorema de Bayes , Bortezomib , Esquema de Medicação , Feminino , Humanos , Masculino , Dose Máxima Tolerável , Pessoa de Meia-Idade , Neoplasias/tratamento farmacológico , Sunitinibe , Neoplasias da Glândula Tireoide/tratamento farmacológico
11.
Oncogene ; 30(35): 3802-12, 2011 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-21478903

RESUMO

Cancer progression involves multiple complex and interdependent steps, including progressive proliferation, angiogenesis and metastases. The complexity of these processes requires a comprehensive elucidation of the integrated signaling networks for better understanding. EAPII interacts with multiple cancer-related proteins, but its biological significance in cancer development remains unknown. In this report we identified the elevated level of EAPII protein in non-small-cell lung carcinoma (NSCLC) patients and NSCLC cell lines in culture. The oncogenic role of EAPII in lung cancer development was demonstrated using NSCLC cells with genetic manipulations that influence EAPII expression: EAPII overexpression increases proliferation of NSCLC cells with an accelerated transition of cell cycle and facilitates xenograft tumor growth in vivo; EAPII knockdown results in apoptosis of NSCLC cells and reduces xenograft tumor formation. To further explore the mechanism of EAPII's oncogenic role in lung cancer development and to elucidate the potential signaling pathway(s) that EAPII may impact, we employed antibody array to investigate the alternation of the major signaling pathways in NSCLC cells with altered EAPII level. We found that EAPII overexpression significantly activated Raf1 and ERK1/2, but not c-Jun N-terminal kinase and p38 pathways. Consistently, the protein and mRNA levels of MYC and cyclin D1, which are targets of the mitogen-activated protein kinase/extracellular signal-regulated kinase (MAPK-ERK) pathway, are significantly increased by EAPII overexpression. Taken together, we demonstrated that EAPII is an oncogenic factor and the activation of MAPK-ERK signaling pathway by EAPII may contribute to lung cancer development.


Assuntos
Carcinoma Pulmonar de Células não Pequenas/metabolismo , Neoplasias Pulmonares/metabolismo , Quinases de Proteína Quinase Ativadas por Mitógeno/biossíntese , Proteínas Nucleares/fisiologia , Oncogenes/fisiologia , Fatores de Transcrição/fisiologia , Apoptose/genética , Carcinoma Pulmonar de Células não Pequenas/genética , Carcinoma Pulmonar de Células não Pequenas/patologia , Linhagem Celular Tumoral , Proliferação de Células , Proteínas de Ligação a DNA , Ativação Enzimática , Técnicas de Silenciamento de Genes , Humanos , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/patologia , Proteínas Nucleares/genética , Oncogenes/genética , Diester Fosfórico Hidrolases , Fatores de Transcrição/genética
12.
Oncogene ; 29(6): 822-30, 2010 Feb 11.
Artigo em Inglês | MEDLINE | ID: mdl-19935702

RESUMO

Faithful and efficient transmission of biological signals through mitogen-activated protein kinase (MAPK) pathways requires engagement of highly regulated cellular machinery in response to diverse environmental cues. Here, we report a novel mechanism controlling signal relay between two MAP3Ks, apoptosis signal-regulating kinase (ASK) 1 and ASK2. We show that ASK2 specifically interacts with 14-3-3 proteins through phosphorylated S964. Although a 14-3-3-binding defective mutant of ASK1 (S967A) has no effect on the ASK2/14-3-3 interaction, both overexpression of the analogous ASK2 (S964A) mutant and knockdown of ASK2 dramatically reduced the amount of ASK1 complexed with 14-3-3. These data suggest a dominant role of ASK2 in 14-3-3 control of ASK1 function. Indeed, ASK2 S964A-induced dissociation of 14-3-3 from ASK1 correlated with enhanced phosphorylation of ASK1 at T838 and increased c-Jun N-terminal kinase phosphorylation, the two biological readouts of ASK1 activation. Our results suggest a model in which upstream signals couple ASK2 S964 phosphorylation to the ASK1 signalosome through dual engagement of 14-3-3.


Assuntos
Proteínas 14-3-3/metabolismo , MAP Quinase Quinase Quinase 5/metabolismo , MAP Quinase Quinase Quinases/metabolismo , Transdução de Sinais , Motivos de Aminoácidos , Sequência de Aminoácidos , Animais , Células COS , Chlorocebus aethiops , Células HeLa , Humanos , MAP Quinase Quinase Quinases/química , Fosforilação , Especificidade por Substrato
13.
J Clin Pharm Ther ; 31(4): 401-6, 2006 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-16882113

RESUMO

Chronic myelomonocytic leukaemia (CMML) is a preleukaemic condition with myeloproliferative features, and classified as a part of myelodysplastic syndrome (MDS). Other than alkylating agents and topoisomerase II inhibitors, there is less evidence that chemotherapeutic drugs are associated with therapy-related CMML, acute leukaemia or MDS. We present a patient who developed CMML within 2 years of platinum-based chemotherapy for a metastatic non-small cell lung cancer. He received a cumulative dose of 240 mg/m(2) of cisplatin, and 1123 mg/m(2) of carboplatin before developing CMML. The cytogenetic study revealed trisomy 8. This is the first reported case that links platinum-based therapy with development of CMML with trisomy 8. Although the relationship between platinum therapy and the development of CMML is difficult to assess due to combinational nature of therapy in most cases, physicians should consider the possibility of CMML in patients with symptoms or signs suggestive of haematologic malignancy after platinum therapy.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Cisplatino/efeitos adversos , Leucemia Mielomonocítica Crônica/induzido quimicamente , Neoplasias Pulmonares/tratamento farmacológico , Etoposídeo/administração & dosagem , Evolução Fatal , Humanos , Leucemia Mielomonocítica Crônica/fisiopatologia , Masculino , Pessoa de Meia-Idade
14.
Ann Oncol ; 15(8): 1187-93, 2004 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-15277257

RESUMO

BACKGROUND: R115777 (tipifarnib, Zarnestra) is a farnesyl transferase inhibitor that blocks the farnesylation of proteins involved in signal transduction pathways critical for cell proliferation and survival. This multicenter phase II study was conducted to determine the efficacy, tolerability and pharmacokinetics of R115777 in patients with relapsed small-cell lung cancer (SCLC). PATIENTS AND METHODS: Patients who had a partial or complete response to their initial chemotherapy regimen, followed by at least 3 months off treatment before relapse (sensitive relapse) were eligible. R115777 was administered in 3-week cycles at a dose of 400 mg orally twice daily for 14 consecutive days followed by 7 days off treatment. RESULTS: Twenty-two patients were enrolled. The median progression-free survival was 1.4 months and median overall survival was 6.8 months. Non-hematological toxicities were predominantly grade 1-2 and included nausea (64%) and fatigue (60%). Grade 3-4 granulocytopenia and thrombocytopenia occurred in 27% and 23% of patients, respectively. Febrile neutropenia was not observed. Pharmacokinetic studies demonstrated peak plasma concentrations of R115777 2.6-4.5 h after oral dosing and no significant drug accumulation. The trial was terminated because no objective responses were observed in 20 patients evaluable for response. CONCLUSIONS: R115777 showed no significant antitumor activity as a single agent in sensitive-relapse SCLC.


Assuntos
Carcinoma de Células Pequenas/tratamento farmacológico , Neoplasias Pulmonares/tratamento farmacológico , Quinolonas/uso terapêutico , Adulto , Idoso , Idoso de 80 Anos ou mais , Alquil e Aril Transferases/antagonistas & inibidores , Alquil e Aril Transferases/farmacologia , Carcinoma de Células Pequenas/patologia , Intervalo Livre de Doença , Farnesiltranstransferase , Feminino , Humanos , Neoplasias Pulmonares/patologia , Masculino , Pessoa de Meia-Idade , Quinolonas/efeitos adversos , Quinolonas/farmacocinética , Recidiva , Transdução de Sinais , Resultado do Tratamento
15.
Endocr Relat Cancer ; 11(2): 191-205, 2004 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-15163298

RESUMO

The ras family of proto-oncogenes are upstream mediators of several essential cellular signal transduction pathways involved in cell proliferation and survival. Point mutations of ras oncogenes result in constitutively active Ras and have been shown to be oncogenic. However, ras activation can occur in the absence of ras mutations secondary to upstream receptor activation. The first important step in Ras activation is farnesylation by farnesyl transferase, and inhibitors of this enzyme have been demonstrated to inhibit Ras signaling, and have anti-tumor effects. However, it is now clear that farnesyl transferase inhibitors (FTIs) have activity independent of Ras, most likely due to effects on prenylated proteins downstream of Ras, which explains their activity in several malignancies, including breast cancer, where ras mutations are rare. Several FTIs are in clinical development for the treatment of solid tumors. Preclinical evidence suggests that FTIs can inhibit breast cancers in vitro and in vivo, and a phase II trial of the FTI, R115777, in patients with advanced breast cancer produced encouraging results. Based on prior successful outcomes with agents targeting the estrogen and epidermal growth factor receptor pathways in breast cancer, the FTIs, used alone or more likely with other agents, may be the next exciting targeted therapy in breast cancer.


Assuntos
Alquil e Aril Transferases/antagonistas & inibidores , Antineoplásicos/farmacologia , Neoplasias da Mama/tratamento farmacológico , Inibidores Enzimáticos/farmacologia , Alquil e Aril Transferases/metabolismo , Animais , Neoplasias da Mama/enzimologia , Farnesiltranstransferase , Feminino , Humanos
16.
Support Care Cancer ; 12(5): 338-46, 2004 May.
Artigo em Inglês | MEDLINE | ID: mdl-15064931

RESUMO

The findings presented contribute to quality of life (QOL) research by highlighting the significance of factors affecting the communication by patients with primary-stage squamous cell carcinoma of the head and neck cancer (SCCHN) of their experiences of suffering after treatment to their clinicians. Qualitative research methodology based on open-ended interviews with 18 survivors of American Joint Committee on Cancer primary stage I and II SCCHN were used. The interviews were transcribed verbatim and thematically analyzed. Three important themes emerged: (1). a diminished self (2). fears of addiction, and (3). hopelessness and the loss of meaning in life after SCCHN. The findings indicate that SCCHN patients under-report their experiences mainly due to fear. As a consequence, and perhaps due to a failure on the part of clinicians and patients to adequately address such fears, SCCHN patients may experience greater psychological morbidity, becoming increasingly fatalistic about biomedicine's ability to restore them to health after cancer despite being "cured", or to relieve related symptoms. This qualitative study provides a perspective as to why such under-reporting occurs, thereby potentially enhancing clinician-patient communication and the QOL of SCCHN patients who present with curable disease.


Assuntos
Carcinoma de Células Escamosas/fisiopatologia , Neoplasias de Cabeça e Pescoço/fisiopatologia , Carcinoma de Células Escamosas/terapia , Feminino , Neoplasias de Cabeça e Pescoço/terapia , Humanos , Masculino , Dor/fisiopatologia , Pesquisa Qualitativa , Texas
17.
Eur J Cancer Care (Engl) ; 13(1): 53-64, 2004 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-14961776

RESUMO

The findings presented in this discussion seek to make a contribution to quality of life (QOL) research, by highlighting the import of factors affecting the communication of primary stage head and neck cancer patient's experiences of suffering after treatments by their clinicians. Qualitative research methodology based on open-ended interviews with 18 survivors of American Joint Committee on Cancer (AJCC) Stage I and Stage II, squamous cell carcinoma of the head and neck (SCCHN) were used. The interviews were transcribed verbatim and thematically analysed. In this preliminary analysis, three important themes emerged: (1) a self diminished by cancer; (2) the fear of addiction to pain medications; and (3) hopelessness and the loss of meaning in life after SCCHN. Our present findings indicate that SCCHN patients understand their experiences of cancer and under-report their experiences of suffering mainly because of fear. These include fears of: being further diminished by SCCHN, fears of addiction, and an inability to cope with the additional losses associated with SCCHN. As a consequence, and perhaps, because of a failure the part of clinicians and patients to adequately address these fears, SCCHN patients may also experience greater psychological morbidity, becoming fatalistic about biomedicine's ability to restore them to health after cancer, or related symptoms, including pain, despite being 'cured.' This study provides a perspective on why this under-reporting occurs, thereby potentially enhancing clinician-patient communication and the QOL of SCCHN patients who present with curable disease.


Assuntos
Carcinoma de Células Escamosas/psicologia , Neoplasias de Cabeça e Pescoço/psicologia , Qualidade de Vida , Adulto , Idoso , Idoso de 80 Anos ou mais , Comunicação , Medo/psicologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Dor/etiologia , Satisfação do Paciente , Relações Médico-Paciente , Grupos de Autoajuda
18.
Semin Radiat Oncol ; 12(1 Suppl 1): 46-9, 2002 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-11917284

RESUMO

A prospective randomized study was conducted to determine whether amifostine (Ethyol) reduces the rate of severe esophagitis and hematologic and pulmonary toxicity associated with chemoradiation or improves control of non-small cell lung cancer (NSCLC). Sixty patients with inoperable stage II or III NSCLC were treated with concurrent chemoradiotherapy. Both groups received thoracic radiation therapy (TRT) with 1.2 Gy/fraction, 2 fraction per day, 5 days per week for a total dose 69.6 Gy. All patients received oral etoposide (VP-16), 50 mg Bid, 30 minutes before TRT beginning day 1 for 10 days, repeated on day 29, and cisplatin 50 mg/m(2) intravenously on days 1, 8, 29, and 36. Patients in the study group received amifostine, 500 mg intravenously, twice weekly before chemoradiation (arm 1); patients in the control group received chemoradiation without amifostine (arm 2). Patient and tumor characteristics were distributed equally in both groups. Of the 60 patients enrolled, 53 were evaluable (27 in arm 1, 26 in arm 2) with a median follow-up of 6 months. Median survival times were 26 months for arm 1 and 15 months for arm 2, not statistically significantly different. Morphine intake to reduce severe esophagitis was significantly lower in arm 1 (2 of 27, 7.4%) than arm 2 (8 of 26, 31%; P =.03). Acute pneumonitis was significantly lower in arm 1 (1 of 27, 3.7%) than in arm 2 (6 of 26, 23%; P =.037). Hypotension (20 mm Hg decrease from baseline blood pressure) was significantly more frequent in arm 1 (19 of 27, 70%) than arm 2 (1 of 26, 3.8%; P =.0001). Only 1 patient discontinued treatment because of hypotension. These preliminary results showed that amifostine significantly reduced acute severe esophagitis and pneumonitis. Further observation is required to assess long-term efficacy.


Assuntos
Amifostina/uso terapêutico , Antineoplásicos Fitogênicos/uso terapêutico , Carcinoma Pulmonar de Células não Pequenas/radioterapia , Etoposídeo/uso terapêutico , Neoplasias Pulmonares/radioterapia , Lesões por Radiação/prevenção & controle , Protetores contra Radiação/uso terapêutico , Adulto , Idoso , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Carcinoma Pulmonar de Células não Pequenas/mortalidade , Terapia Combinada , Esofagite/etiologia , Esofagite/prevenção & controle , Feminino , Humanos , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/mortalidade , Masculino , Pessoa de Meia-Idade , Pneumonite por Radiação/prevenção & controle
19.
Cancer ; 92(9): 2364-73, 2001 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-11745292

RESUMO

BACKGROUND: Thalidomide has been shown to have antiangiogenic effects in preclinical models as well as a significant antitumor effect in hematologic tumors such as multiple myeloma. The authors performed this Phase II study to determine the activity, toxicity profile, and antiangiogenic effect of thalidomide in patients with locoregionally recurrent or metastatic squamous cell carcinoma of the head and neck. METHODS: Twenty-one patients with recurrent or metastatic squamous cell carcinoma of the head and neck were treated with single-agent thalidomide. All patients had received radiation therapy, and most had undergone surgery (95%) and/or chemotherapy (90%). Thalidomide was initiated at 200 mg;3>daily and increased to a target dose of 1000 mg daily. Patients continued treatment until disease progression, unacceptable toxicity, or death occurred. RESULTS: All 21 patients eventually developed progressive disease. Median time to progression was 50 days (95% confidence interval, 28-70), with median overall survival time of 194 days (95% lower confidence boundary, 151), similar to the progression and survival times reported for this patient group with other agents. Thalidomide was generally well tolerated, with few patients experiencing Grades 3 to 4 toxicities. Serum vascular endothelial growth factor and basic fibroblast growth factor levels increased in six of seven patients, for whom paired serum samples were available and all of whom had progressive disease. CONCLUSIONS: In this heavily pretreated population of patients with advanced squamous cell carcinoma of the head and neck, thalidomide does not appear to have single-agent antitumor activity. Further evaluation of the mechanism of action of thalidomide is indicated. Potentially, future evaluations of thalidomide may be performed in combination with other antiangiogenic or cytotoxic agents in patients with earlier stage disease or in patients with minimal residual disease.


Assuntos
Inibidores da Angiogênese/farmacologia , Carcinoma de Células Escamosas/tratamento farmacológico , Neoplasias de Cabeça e Pescoço/tratamento farmacológico , Recidiva Local de Neoplasia/tratamento farmacológico , Talidomida/farmacologia , Administração Oral , Adulto , Idoso , Idoso de 80 Anos ou mais , Inibidores da Angiogênese/efeitos adversos , Carcinoma de Células Escamosas/patologia , Progressão da Doença , Feminino , Neoplasias de Cabeça e Pescoço/patologia , Humanos , Masculino , Pessoa de Meia-Idade , Análise de Sobrevida , Talidomida/efeitos adversos , Resultado do Tratamento
20.
Ethn Health ; 6(3-4): 165-77, 2001.
Artigo em Inglês | MEDLINE | ID: mdl-11696928

RESUMO

BACKGROUND: This study was designed to determine if race and age are independent prognostic factors for survival in patients treated for squamous cell carcinoma of the oral cavity and pharynx. METHODS: Retrospective study. RESULTS: Out of 909 patients registered, 815 (90%) were white and 94 (10%) were African-American. The median age was 60 years (range 19-93). The African-American patients had a significantly lower 5 year survival rate of 27.6% (95% CI 19.9-38.3) compared with white patients with a survival rate of 52.0% (95% CI 48.7-55.6) (P < 0.001). The greatest racial disparities in survival were observed in patients under 60 years of age [29.2% (95% CI 19.5-43.6) vs 60.9% (95% CI 56.3-66.0) for African-American and white patients, respectively, P < 0.001], and in African-American men compared with white men [20.2% (95% CI 12.6-30.2) vs 51.0% (95% CI 46.7-53.0), P < 0.001]. A multivariate Cox model, stratified according to stage of disease, indicated that race, age, and type of treatment were statistically significant predictors of survival. After adjusting for race and treatment received, African-American patients had a relative risk of dying of 1.61 (95% CI 1.23-2.10) compared with white patients. All patients 60 years of age and older had a higher risk of dying 1.59 (95% CI 1.31-1.92). Compared with surgical treatment alone, radiotherapy and other treatments were both associated with increased risk of dying with respective relative risks of 1.34 (95% CI 1.01-1.76) and 1.94 (95% CI 1.52-1.48). CONCLUSIONS: African-American patients had poorer survival outcomes, with race and age emerging as significant independent predictors of survival after treatment for oral and pharyngeal cancer, compared with their white counterparts. Primary and secondary prevention programs that target younger patients at high risk might reduce environmental risk factors such as smoking and alcohol consumption, which may play a greater role in the acquired susceptibility for oral and pharyngeal cancer in African-American males.


Assuntos
População Negra , Carcinoma de Células Escamosas/mortalidade , Neoplasias Bucais/mortalidade , Neoplasias Faríngeas/mortalidade , População Branca , Adulto , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Carcinoma de Células Escamosas/etnologia , Carcinoma de Células Escamosas/patologia , Distribuição de Qui-Quadrado , Feminino , Humanos , Estilo de Vida , Masculino , Pessoa de Meia-Idade , Neoplasias Bucais/etnologia , Neoplasias Bucais/patologia , Análise Multivariada , Neoplasias Faríngeas/etnologia , Neoplasias Faríngeas/patologia , Prognóstico , Modelos de Riscos Proporcionais , Fatores de Risco , Fatores Socioeconômicos , Taxa de Sobrevida , Texas/epidemiologia
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