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1.
Nature ; 539(7627): 112-117, 2016 11 03.
Artigo em Inglês | MEDLINE | ID: mdl-27595394

RESUMO

Clear cell renal cell carcinoma (ccRCC) is characterized by inactivation of the von Hippel-Lindau tumour suppressor gene (VHL). Because no other gene is mutated as frequently in ccRCC and VHL mutations are truncal, VHL inactivation is regarded as the governing event. VHL loss activates the HIF-2 transcription factor, and constitutive HIF-2 activity restores tumorigenesis in VHL-reconstituted ccRCC cells. HIF-2 has been implicated in angiogenesis and multiple other processes, but angiogenesis is the main target of drugs such as the tyrosine kinase inhibitor sunitinib. HIF-2 has been regarded as undruggable. Here we use a tumourgraft/patient-derived xenograft platform to evaluate PT2399, a selective HIF-2 antagonist that was identified using a structure-based design approach. PT2399 dissociated HIF-2 (an obligatory heterodimer of HIF-2α-HIF-1ß) in human ccRCC cells and suppressed tumorigenesis in 56% (10 out of 18) of such lines. PT2399 had greater activity than sunitinib, was active in sunitinib-progressing tumours, and was better tolerated. Unexpectedly, some VHL-mutant ccRCCs were resistant to PT2399. Resistance occurred despite HIF-2 dissociation in tumours and evidence of Hif-2 inhibition in the mouse, as determined by suppression of circulating erythropoietin, a HIF-2 target and possible pharmacodynamic marker. We identified a HIF-2-dependent gene signature in sensitive tumours. Gene expression was largely unaffected by PT2399 in resistant tumours, illustrating the specificity of the drug. Sensitive tumours exhibited a distinguishing gene expression signature and generally higher levels of HIF-2α. Prolonged PT2399 treatment led to resistance. We identified binding site and second site suppressor mutations in HIF-2α and HIF-1ß, respectively. Both mutations preserved HIF-2 dimers despite treatment with PT2399. Finally, an extensively pretreated patient whose tumour had given rise to a sensitive tumourgraft showed disease control for more than 11 months when treated with a close analogue of PT2399, PT2385. We validate HIF-2 as a target in ccRCC, show that some ccRCCs are HIF-2 independent, and set the stage for biomarker-driven clinical trials.


Assuntos
Fatores de Transcrição Hélice-Alça-Hélice Básicos/antagonistas & inibidores , Carcinoma de Células Renais/tratamento farmacológico , Carcinoma de Células Renais/metabolismo , Indanos/farmacologia , Indanos/uso terapêutico , Neoplasias Renais/tratamento farmacológico , Neoplasias Renais/metabolismo , Sulfonas/farmacologia , Sulfonas/uso terapêutico , Animais , Translocador Nuclear Receptor Aril Hidrocarboneto/genética , Translocador Nuclear Receptor Aril Hidrocarboneto/metabolismo , Fatores de Transcrição Hélice-Alça-Hélice Básicos/genética , Fatores de Transcrição Hélice-Alça-Hélice Básicos/metabolismo , Sítios de Ligação , Carcinoma de Células Renais/genética , Carcinoma de Células Renais/patologia , Linhagem Celular Tumoral , Transformação Celular Neoplásica , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Eritropoetina/antagonistas & inibidores , Eritropoetina/sangue , Feminino , Regulação Neoplásica da Expressão Gênica , Humanos , Indanos/administração & dosagem , Indóis/farmacologia , Indóis/uso terapêutico , Neoplasias Renais/genética , Neoplasias Renais/patologia , Masculino , Camundongos , Camundongos Endogâmicos NOD , Camundongos SCID , Terapia de Alvo Molecular , Mutação , Pirróis/farmacologia , Pirróis/uso terapêutico , Reprodutibilidade dos Testes , Sulfonas/administração & dosagem , Sunitinibe , Ensaios Antitumorais Modelo de Xenoenxerto
2.
Oncologist ; 22(4): 369-374, 2017 04.
Artigo em Inglês | MEDLINE | ID: mdl-28314841

RESUMO

Multiple factors critical to the effectiveness of academic phase I cancer programs were assessed among 16 academic centers in the U.S. Successful cancer centers were defined as having broad phase I and I/II clinical trial portfolios, multiple investigator-initiated studies, and correlative science. The most significant elements were institutional philanthropic support, experienced clinical research managers, robust institutional basic research, institutional administrative efforts to reduce bureaucratic regulatory delays, phase I navigators to inform patients and physicians of new studies, and a large cancer center patient base. New programs may benefit from a separate stand-alone operation, but mature phase I programs work well when many of the activities are transferred to disease-oriented teams. The metrics may be useful as a rubric for new and established academic phase I programs. The Oncologist 2017;22:369-374.


Assuntos
Centros Médicos Acadêmicos , Neoplasias/epidemiologia , Ensaios Clínicos como Assunto , Humanos , Neoplasias/genética , Desenvolvimento de Programas , Estados Unidos
3.
Transfus Apher Sci ; 56(3): 431-433, 2017 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-28512017

RESUMO

Von Willebrand disease (VWD) is the most common congenital bleeding disorder and is due to quantitative or qualitative defects of von Willebrand factor (VWF). Acquired defects of VWF, termed acquired von Willebrand syndrome (AVWS), are due to a host of different mechanisms. Autoantibody-mediated AVWS may be associated with lymphoproliferative or immunological disorders, such as systemic lupus erythematosus (SLE). A large majority of AVWS cases are type 1 or type 2A-like and patients tend to have a mild to moderate bleeding tendency. We report a case of severe autoimmune AVWS in a woman with SLE who presented with clinical and laboratory features of type 3 VWD (undetectable VWF antigen, ristocetin cofactor activity, and VWF multimers). A mixing study demonstrated an inhibitor to VWF (6BU/mL). Her bleeds were managed with antifibrinolytics, recombinant activated factor VII, and activated prothrombin complex concentrate. She was initially treated with steroids and intravenous immunoglobulin therapy. However, her bleeding symptoms continued until she was treated with rituximab, and her VWF parameters normalized. She relapsed two years later due to non-compliance with her immunosuppressive medications and expired another two years later secondary to complications of sepsis and uremic pericarditis. This case emphasizes the importance of aggressive initial therapy of SLE to reduce secondary complications, frequent patient monitoring, and continued treatment of the underlying autoimmune disorder in patients with AVWS.


Assuntos
Doenças Autoimunes/diagnóstico , Doenças de von Willebrand/diagnóstico , Adulto , Doenças Autoimunes/mortalidade , Doenças Autoimunes/patologia , Feminino , Humanos , Análise de Sobrevida , Adulto Jovem , Doenças de von Willebrand/mortalidade , Doenças de von Willebrand/patologia
4.
J Urol ; 195(1): 180-7, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26300218

RESUMO

PURPOSE: In clear cell renal cell carcinoma BAP1 and PBRM1 are 2 of the most commonly mutated genes (10% to 15% and 40% to 50%, respectively). We sought to determine the prognostic significance of PBRM1 and BAP1 expression in clear cell renal cell carcinoma. MATERIALS AND METHODS: We used immunohistochemistry to assess PBRM1 protein expression in 1,479 primary clear cell renal cell carcinoma tumors that were previously stained for BAP1. A centralized pathologist reviewed all cases and categorized tumors as positive or deficient for PBRM1 and BAP1. Kaplan-Meier and Cox regression models were used to evaluate association of PBRM1 and BAP1 expression with the risk of death from renal cell carcinoma and the risk of metastasis after adjustment for age and the Mayo Clinic SSIGN (stage, size, grade and necrosis) score. RESULTS: PBRM1 and BAP1 expression was PBRM1+ BAP1+ in 40.1% of tumors, PBRM1- BAP1+ in 48.6%, PBRM1+ BAP1- in 8.7% and PBRM1- BAP1- in 1.8%. The incidence of PBRM1 and BAP1 loss in the same tumor was significantly lower than expected (actual 1.8% vs expected 5.3%, p <0.0001). Compared to patients with PBRM1+ BAP1+ tumors those with PBRM1- BAP1+ lesions were more likely to die of renal cell carcinoma (HR 1.39, p = 0.035), followed by those with PBRM1+ BAP1- and PBRM1- BAP1- tumors (HR 3.25 and 5.2, respectively, each p <0.001). PBRM1 and BAP1 expression did not add independent prognostic information to the SSIGN score. CONCLUSIONS: PBRM1 and BAP1 expression identified 4 clinical subgroups of patients with clear cell renal cell carcinoma who had divergent clinical outcomes. The clinical value of these biomarkers will be fully realized when therapies targeting pathways downstream of PBRM1 and BAP1 are developed.


Assuntos
Carcinoma de Células Renais/classificação , Carcinoma de Células Renais/genética , Neoplasias Renais/classificação , Neoplasias Renais/genética , Proteínas Nucleares/genética , Fatores de Transcrição/genética , Proteínas Supressoras de Tumor/genética , Ubiquitina Tiolesterase/genética , Adulto , Idoso , Idoso de 80 Anos ou mais , Proteínas de Ligação a DNA , Feminino , Regulação Neoplásica da Expressão Gênica , Humanos , Masculino , Pessoa de Meia-Idade , Prognóstico , Células Tumorais Cultivadas , Adulto Jovem
5.
Blood ; 121(14): 2669-77, 2013 Apr 04.
Artigo em Inglês | MEDLINE | ID: mdl-23365458

RESUMO

Mutations in the transcription factor GATA2 underlie the syndrome of monocytopenia and B- and natural killer (NK)-cell lymphopenia associated with opportunistic infections and cancers. In addition, patients have recurrent and severe viral infections. NK cells play a critical role in mediating antiviral immunity. Human NK cells are thought to mature in a linear fashion, with the CD56(bright) stage preceding terminal maturation to the CD56(dim) stage, considered the most enabled for cytotoxicity. Here we report an NK cell functional defect in GATA2-deficient patients and extend this genetic lesion to what is considered to be the original NK cell-deficient patient. In most cases, GATA2 deficiency is accompanied by a severe reduction in peripheral blood NK cells and marked functional impairment. The NK cells detected in peripheral blood of some GATA2-deficient patients are exclusively of the CD56(dim) subset, which is recapitulated on in vitro NK cell differentiation. In vivo, interferon α treatment increased NK cell number and partially restored function but did not correct the paucity of CD56(bright) cells. Thus, GATA2 is required for the maturation of human NK cells and the maintenance of the CD56(bright) pool in the periphery. Defects in GATA2 are a novel cause of profound NK cell dysfunction.


Assuntos
Antígeno CD56/imunologia , Diferenciação Celular/imunologia , Fator de Transcrição GATA2/genética , Células Matadoras Naturais/imunologia , Linfopenia/genética , Antígenos CD34/metabolismo , Antígeno CD56/metabolismo , Citotoxicidade Imunológica/imunologia , Fator de Transcrição GATA2/imunologia , Fator de Transcrição GATA2/metabolismo , Humanos , Imunofenotipagem , Células K562 , Células Matadoras Naturais/citologia , Células Matadoras Naturais/metabolismo , Ativação Linfocitária/imunologia , Contagem de Linfócitos , Linfopenia/imunologia , Linfopenia/metabolismo , Células Estromais/citologia , Subpopulações de Linfócitos T/citologia , Subpopulações de Linfócitos T/imunologia , Subpopulações de Linfócitos T/metabolismo
6.
Cancer Sci ; 105(8): 1040-8, 2014 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-24837299

RESUMO

Epidermal growth factor receptor (EGFR) and human epidermal growth factor receptor 2 (HER2) are validated molecular targets in cancer therapy. Dual blockade has been explored and one such agent, lapatinib, is in clinical practice but with modest activity. Through chemical screening, we discovered a novel EGFR and HER2 inhibitor, S-222611, that selectively inhibited both kinases with IC50 s below 10 nmol/L. S-222611 also inhibited intracellular kinase activity and the growth of EGFR-expressing and HER2-expressing cancer cells. In addition, S-222611 showed potent antitumor activity over lapatinib in a variety of xenograft models. In evaluations with two patient-oriented models, the intrafemoral implantation model and the intracranial implantation model, S-222611 exhibited excellent activity and could be effective against bone and brain metastasis. Compared to neratinib and afatinib, irreversible EGFR/HER2 inhibitors, S-222611 showed equivalent or slightly weaker antitumor activity but a safer profile. These results indicated that S-222611 is a potent EGFR and HER2 inhibitor with substantially better antitumor activity than lapatinib at clinically relevant doses. Considering the safer profile than for irreversible inhibitors, S-222611 could be an important option in future cancer therapy.


Assuntos
Antineoplásicos/farmacologia , Receptores ErbB/antagonistas & inibidores , Inibidores de Proteínas Quinases/farmacologia , Quinazolinas/farmacologia , Receptor ErbB-2/antagonistas & inibidores , Animais , Linhagem Celular Tumoral , Modelos Animais de Doenças , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Camundongos , Camundongos Nus , Camundongos SCID , Ensaios Antitumorais Modelo de Xenoenxerto
7.
Cancer ; 120(7): 1059-67, 2014 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-24382589

RESUMO

BACKGROUND: The majority of patients diagnosed with clear cell renal cell carcinoma (ccRCC) have low-risk disease with a < 10% chance of ccRCC-specific death. DNA sequencing revealed that mutations in BAP1 (BRCA1 associated protein-1) occur in 5% to 15% of ccRCC cases and are associated with poor outcomes. The vast majority of BAP1 mutations abolish protein expression. In this study, we used a highly sensitive and specific immunohistochemistry (IHC) assay to test whether BAP1 expression is an independent marker of ccRCC-specific survival, particularly in patients with low-risk disease. METHODS: BAP1 expression was assessed, using IHC, in 1479 patients who underwent nephrectomy to treat clinically localized ccRCC. A centralized pathologist dichotomized patients as either BAP1-positive or BAP1-negative. The authors employed Kaplan-Meier and Cox regression models to associate BAP1 expression with cancer-specific survival. RESULTS: A total of 10.5% of tumors were BAP1-negative, 84.8% of tumors were BAP1-positive, and 4.6% of tumors had ambiguous staining for BAP1. Patients with BAP1-negative tumors have an increased risk of ccRCC-related death (hazard ratio [HR] = 3.06; 95% confidence interval [CI] = 2.28-4.10; P = 6.77 × 10(-14) ). BAP1 expression remained an independent marker of prognosis after adjusting for the UCLA integrated staging system (UISS) (HR = 1.67; 95% CI = 1.24-2.25; P < .001). Finally, BAP1 was an independent prognostic marker in low-risk patients with a Mayo Clinic stage, size, grade, and necrosis (SSIGN) score of ≤ 3 (HR = 3.24; 95% CI = 1.26-8.33; P = .015). CONCLUSIONS: This study used a large patient cohort to demonstrate that BAP1 expression is an independent marker of prognosis in patients with low-risk (SSIGN≤ 3) ccRCC.


Assuntos
Carcinoma de Células Renais/metabolismo , Neoplasias Renais/metabolismo , Proteínas Supressoras de Tumor/biossíntese , Ubiquitina Tiolesterase/biossíntese , Adulto , Idoso , Idoso de 80 Anos ou mais , Biomarcadores Tumorais/biossíntese , Biomarcadores Tumorais/genética , Carcinoma de Células Renais/genética , Estudos de Coortes , Feminino , Humanos , Imuno-Histoquímica , Neoplasias Renais/genética , Masculino , Pessoa de Meia-Idade , Prognóstico , Fatores de Risco , Análise de Sobrevida , Proteínas Supressoras de Tumor/genética , Ubiquitina Tiolesterase/genética
8.
Biomed Microdevices ; 15(4): 673-681, 2013 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-23109037

RESUMO

Combining the power of immunomagnetic assay and microfluidic microchip operations, we successfully detected rare CTCs from clinical blood samples. The microfluidic system is operated in a flip-flop mode, where a computer-controlled rotational holder with an array of microfluidic chips inverts the microchannels. We have demonstrated both theoretically and experimentally that the direction of red blood cell (RBC) sedimentation with regards to the magnetic force required for cell separation is important for capture efficiency, throughput, and purity. The flip-flop operation reduces the stagnation of RBCs and non-specific binding on the capture surface by alternating the direction of the magnetic field with respect to gravity. The developed immunomagnetic microchip-based screening system exhibits high capture rates (more than 90%) for SkBr3, PC3, and Colo205 cell lines in spiked screening experiments and successfully isolates CTCs from patient blood samples. The proposed motion controlled microchip-based immunomagnetic system shows great promise as a clinical tool for cancer diagnosis and prognosis.


Assuntos
Separação Imunomagnética/instrumentação , Técnicas Analíticas Microfluídicas/instrumentação , Movimento (Física) , Nanotecnologia/instrumentação , Células Neoplásicas Circulantes/patologia , Sedimentação Sanguínea , Linhagem Celular Tumoral , Eritrócitos/citologia , Humanos , Campos Magnéticos , Neoplasias/sangue , Viscosidade
9.
Int J Cancer ; 128(12): 2823-32, 2011 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-20734393

RESUMO

Conventional chemotherapy is commonly used for advanced stages of bladder cancer with modest success and high morbidity. Identifying markers of resistance will allow clinicians to tailor treatment to a specific patient population. T24-tumorigenic cell line was grown orthotopically in nude mice and monitored using bioluminescence imaging and microcomputed tomography until they developed metastases. Stable sublines were then developed from primary bladder (T24-P), lung (T24-L) and bone (T24-B) tissues. Chromosomal analysis and DNA microarray were used to characterize these sublines. Real-time quantitative polymerase chain reaction and immunohistochemistry were used for validation. Epigenetic modifiers were used to study gene regulation. The cell viability was quantified with MTT assay. Chromosomal analysis revealed multiple alterations in metastatic cell lines compared to T24-P. DNA microarray analysis showed that taxol resistance-associated gene (TRAG) 3 was the most upregulated gene. From real-time quantitative polymerase chain reaction and immunohistochemistry, TRAG3 was significantly higher in T24-L and T24-B than T24-P. TRAG3 gene expression is likely controlled by DNA methylation but not histone acetylation. Interestingly, T24-B and T24-L cells were more resistant than T24-P to treatment with antimicrotubule agents such as docetaxel, paclitaxel and vinblastine. TRAG3 mRNA expression was higher in 20% of patients with ≤ pT2 (n = 10) and 60% of patients with ≥ pT3 (n = 20) compared to normal adjacent tissue (p = 0.05). In addition, the median TRAG3 expression was 6.7-fold higher in ≥ pT3 tumors compared to ≤ pT2 tumors. Knowing the status of TRAG3 expression could help clinicians tailor treatment to a particular patient population that could benefit from treatment, while allocating patients with resistant tumors to new experimental therapies.


Assuntos
Carcinoma de Células de Transição/genética , Proteínas de Neoplasias/genética , Regulação para Cima , Neoplasias da Bexiga Urinária/genética , Adulto , Idoso , Idoso de 80 Anos ou mais , Animais , Sequência de Bases , Carcinoma de Células de Transição/patologia , Primers do DNA , Feminino , Humanos , Masculino , Camundongos , Camundongos Nus , Pessoa de Meia-Idade , Metástase Neoplásica , Análise de Sequência com Séries de Oligonucleotídeos , Reação em Cadeia da Polimerase , Neoplasias da Bexiga Urinária/patologia
10.
Platelets ; 21(6): 460-3, 2010.
Artigo em Inglês | MEDLINE | ID: mdl-20536288

RESUMO

Platelet aggregation study is performed to investigate platelet function abnormality. A normal healthy control sample is usually run with the patient sample as a quality control measure. At our institution, we observed variations in platelet aggregation responses in our normal repeat controls. Therefore, we analysed aggregation parameters in these controls. Whole blood aggregation studies were performed with adenosine diphosphate (ADP), arachidonic acid (AA), collagen and ristocetin. Adenosine triphosphate (ATP) secretion was also measured simultaneously by leuciferin-leuciferase reaction. During a 5-year period, a total of 86 studies were performed on seven controls. Aggregations were within the acceptable range in 67% of the time. Collagen was the most affected agonist in our study. On five occasions, four controls had subnormal aggregations with two agonists. All abnormal responses were hypoaggregation except for two who had hyperaggregation with collagen and AA. Only one out of seven controls was always normal. In the presence of a subnormal control result, a new control was run before releasing the patient's platelet aggregation results. These findings suggest that many physiological factors, other than medications, may affect platelet function even in normal individuals. Therefore, a repeat study at a later date to demonstrate a reproducible abnormality would be prudent before labeling a patient's platelets abnormal.


Assuntos
Plaquetas/fisiologia , Agregação Plaquetária/fisiologia , Difosfato de Adenosina/farmacologia , Trifosfato de Adenosina/sangue , Trifosfato de Adenosina/metabolismo , Adulto , Ácido Araquidônico/farmacologia , Plaquetas/efeitos dos fármacos , Plaquetas/metabolismo , Colágeno/farmacologia , Feminino , Programas Gente Saudável , Humanos , Masculino , Pessoa de Meia-Idade , Agregação Plaquetária/efeitos dos fármacos , Testes de Função Plaquetária/métodos , Controle de Qualidade , Estudos Retrospectivos , Ristocetina/farmacologia
11.
Clin Cancer Res ; 14(4): 1200-7, 2008 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-18281555

RESUMO

PURPOSE: Romidepsin (FK228, depsipeptide, FR901228), a unique cyclic depsipeptide with a histone deacetylase inhibitor (HDACI) activity, is a potential cancer therapeutic agent and currently under clinical trials for several types of cancer. For bladder cancer, romidepsin seems to be a potent antitumor agent from our recent study. In this study, we further delineate a new agent that can enhance both HDACI and antitumor activity of romidepsin. EXPERIMENTAL DESIGN: We screened a chemical library to identify candidate(s) that could enhance romidepsin activity. Chemical synthesis and purification were carried out to produce pure compound to examine its biochemical and antitumor effect on bladder cancer cell lines both in vitro and in vivo. RESULTS: Tranilast, N-(acetoacetyl) anthranilic acid, was first identified as a lead compound from screening, and then, one of the analogues, 2,3-dimethoxycinnamoyl azide (DMCA), seems to be more potent than tranilast. Our data indicate that DMCA can potentiate the HDACI activity of romidepsin and other biological activities, such as cell cycle arrest and apoptosis; these effects were accompanied with the expression of various key cell cycle regulators in different bladder cancer cells. Consistently, DMCA can enhance the in vivo antitumor effect of romidepsin without causing any more weight loss than romidepsin alone. CONCLUSION: DMCA is able to enhance the antitumor effect of romidepsin on bladder cancer from in vitro and in vivo.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/farmacologia , Azidas/administração & dosagem , Cinamatos/administração & dosagem , Neoplasias da Bexiga Urinária/tratamento farmacológico , Animais , Apoptose/efeitos dos fármacos , Western Blotting , Ciclo Celular/efeitos dos fármacos , Proliferação de Células , Depsipeptídeos/administração & dosagem , Inibidores Enzimáticos/administração & dosagem , Histona Desacetilases/metabolismo , Humanos , Camundongos , Camundongos Nus , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Ensaios Antitumorais Modelo de Xenoenxerto , ortoaminobenzoatos/química
12.
Methods Mol Biol ; 1866: 163-171, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30725415

RESUMO

This chapter reviews how total methionine (MET) restriction (MR) of a human brain tumor xenograft, effected by the combination of recombinant L-methionine-α-deamino-γ-lyase (rMETase) and a MET-free diet, greatly potentiates standard chemotherapy for brain tumors in mouse models. The growth of human brain tumor Daoy, SWB77, and D-54 xenografts in nude mice was arrested after the depletion of mouse plasma methionine (MET) with a combination of an MR diet and rMETase and homocysteine to rescue normal cells and tissues. MET was depleted to below 5 µm by this treatment. MR for 10-12 days inhibited tumor growth, but did not prevent tumor regrowth after treatment cessation. A single dose of N,N'-bis(2-chloroethyl)-N-nitrosourea (BCNU), which was ineffective alone, was administered at the end of the MR regimen, and caused a more than 80-day growth delay for Daoy and D-54 and a 20-day growth delay for SWB77. The total MR treatment regimens also increased the efficacy of temozolomide (TMZ) against the SWB77 xenograft when administered at the end of the MET regimen.


Assuntos
Metionina/deficiência , Neoplasias/dietoterapia , Animais , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Colina , Homocisteína/metabolismo , Humanos , Fígado/efeitos dos fármacos , Fígado/patologia , Metionina/sangue , Camundongos Nus , Neoplasias/tratamento farmacológico , Neoplasias/patologia , Temozolomida/farmacologia , Temozolomida/uso terapêutico , Ensaios Antitumorais Modelo de Xenoenxerto
13.
Cancer Epidemiol Biomarkers Prev ; 17(4): 995-1000, 2008 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-18398044

RESUMO

Detection of cancer cells at early stages could potentially increase survival rates in cancer patients. Aberrant promoter hypermethylation is a major mechanism for silencing tumor suppressor genes in many kinds of human cancers. A recent report from our laboratory described the use of quantitative methylation-specific PCR assays for discriminating patients with lung cancer from those without lung cancer using lung biopsies as well as sputum samples. TCF21 is known to be essential for differentiation of epithelial cells adjacent to mesenchyme. Using restriction landmark genomic scanning, a recent study identified TCF21 as candidate tumor suppressor at 6q23-q24 that is epigenetically inactivated in lung and head and neck cancers. Using DNA sequencing technique, we narrowed down a short CpG-rich segment (eight specific CpG sites in the CpG island within exon 1) of the TCF21 gene, which was unmethylated in normal lung epithelial cells but predominantly methylated in lung cancer cell lines. We specifically targeted this short CpG-rich sequence and developed a quantitative methylation-specific PCR assay suitable for high-throughput analysis. We showed the usefulness of this assay in discriminating patients with lung cancer from those without lung cancer using biopsies and sputum samples. We further showed similar applications with multiple other malignancies. Our assay might have important implications in early detection and surveillance of multiple malignancies.


Assuntos
Fatores de Transcrição Hélice-Alça-Hélice Básicos/genética , Biomarcadores Tumorais/genética , Metilação de DNA , Éxons/genética , Neoplasias/genética , Humanos
14.
Urol Oncol ; 26(1): 57-64, 2008.
Artigo em Inglês | MEDLINE | ID: mdl-18190833

RESUMO

Nanoparticles (size in nanometer range) provide a new mode of cancer drug delivery functioning as a carrier for entry through fenestrations in tumor vasculature allowing direct cell access. These particles allow exquisite modification for binding to cancer cell membranes, the microenvironment, or to cytoplasmic or nuclear receptor sites. This results in delivery of high drug concentrations to the targeted cancer cell, with reduced toxicity of normal tissue. Several such engineered drugs are in clinical practice, including liposomal doxorubicin and albumin conjugate paclitaxel. The carrier mediated paclitaxel has already shown significant efficacy in taxane resistant cancers, an approach highly relevant in prostate cancer, where taxanes are the treatment of choice. Other modifications including transferrin receptor and folate receptor targeted drug delivery molecules are in study. This new technology provides many exciting therapeutic approaches for targeted high concentration drug delivery to cancer cells with reduced injury of normal cells.


Assuntos
Antineoplásicos/uso terapêutico , Sistemas de Liberação de Medicamentos/métodos , Nanopartículas , Neoplasias/tratamento farmacológico , Antineoplásicos/administração & dosagem , Desenho de Fármacos , Resistência a Múltiplos Medicamentos/fisiologia , Humanos , Lipossomos , Nanocápsulas
15.
Hematol Oncol Clin North Am ; 21(4): 647-61, vi, 2007 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-17666283

RESUMO

Acquired platelet dysfunction is encountered frequently in clinical practice. The usual clinical presentation is that of mucosal bleeding, epistaxis, or superficial epidermal bleeds. Often, the dysfunctional platelets are related to a medication or a systemic disorder. Normally, when platelets are exposed to damaged endothelium, they adhere to the exposed basement membrane collagen and change their shape from smooth disks to spheres with pseudopodia. Then, they secrete the contents of their granules, a process referred to as the release reaction. Additional platelets form aggregates on those platelets that have adhered to the vessel wall. As a result, the primary hemostatic plug is formed, and bleeding is arrested. This article reviews the various forms of acquired platelet dysfunction that result in decreased platelet aggregation, adhesion, or secretion.


Assuntos
Transtornos Plaquetários/etiologia , Ponte Cardiopulmonar/efeitos adversos , Doença , Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos , Humanos
16.
Neoplasia ; 19(10): 848-855, 2017 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-28923537

RESUMO

This is the first prospective study of the effects of human gut microbiota and metabolites on immune checkpoint inhibitor (ICT) response in metastatic melanoma patients. Whereas many melanoma patients exhibit profound response to ICT, there are fewer options for patients failing ICT-particularly with BRAF-wild-type disease. In preclinical studies, specific gut microbiota promotes regression of melanoma in mice. We therefore conducted a study of the effects of pretreatment gut microbiota and metabolites on ICT Response Evaluation Criteria in Solid Tumors response in 39 metastatic melanoma patients treated with ipilimumab, nivolumab, ipilimumab plus nivolumab (IN), or pembrolizumab (P). IN yielded 67% responses and 8% stable disease; P achieved 23% responses and 23% stable disease. ICT responders for all types of therapies were enriched for Bacteroides caccae. Among IN responders, the gut microbiome was enriched for Faecalibacterium prausnitzii, Bacteroides thetaiotamicron, and Holdemania filiformis. Among P responders, the microbiome was enriched for Dorea formicogenerans. Unbiased shotgun metabolomics revealed high levels of anacardic acid in ICT responders. Based on these pilot studies, both additional confirmatory clinical studies and preclinical testing of these bacterial species and metabolites are warranted to confirm their ICT enhancing activity.


Assuntos
Microbioma Gastrointestinal , Melanoma/etiologia , Melanoma/metabolismo , Metabolômica , Metagenoma , Metagenômica , Adulto , Idoso , Idoso de 80 Anos ou mais , Antineoplásicos Imunológicos/farmacologia , Antineoplásicos Imunológicos/uso terapêutico , Biomarcadores Tumorais , Cromatografia Líquida de Alta Pressão , Análise por Conglomerados , Feminino , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Masculino , Melanoma/tratamento farmacológico , Melanoma/patologia , Metabolômica/métodos , Metagenômica/métodos , Pessoa de Meia-Idade , Terapia de Alvo Molecular , Metástase Neoplásica , Estadiamento de Neoplasias , Prognóstico , Espectrometria de Massas em Tandem , Resultado do Tratamento
17.
Cancer Lett ; 242(2): 222-30, 2006 Oct 28.
Artigo em Inglês | MEDLINE | ID: mdl-16458425

RESUMO

We investigated aberrant methylation in 101 prostate cancers(PCa) and 32 histologically normal prostate tissues. We focused on genes largely in the apoptotic pathway. Methylation frequencies of the genes were Reprimo, 54%; TMS1, 47%; DcR1, 45%; RRAD, 37%; DcR2, 37%; CRBP1, 34%; HPP1, 32%; RIZ1, 31%; DRM/Gremlin, 21%; SOCS1, 20%; DR4, 5%; DR5, 1%. Methylation of Reprimo and TMS1 correlate with preoperative serum prostate-specific antigen. Methylation of TMS1, DcR1, DcR2, and CRBP1 correlate with Gleason score. Methylation of TMS1 and unmethylation of both DcR1 and DcR2 correlate with poorer disease free survival by univariate and multivariate analyses. Our data suggest that methylation of multiple genes may be involved in pathogenesis and correlate with prognosis of PCa.


Assuntos
Apoptose , Metilação de DNA , Neoplasias da Próstata/genética , Neoplasias da Próstata/patologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Sequência de Bases , DNA/química , DNA/metabolismo , Primers do DNA/química , Intervalo Livre de Doença , Humanos , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Prognóstico , Neoplasias da Próstata/diagnóstico
18.
Urol Oncol ; 24(2): 152-60, 2006.
Artigo em Inglês | MEDLINE | ID: mdl-16520279

RESUMO

Prostate cancer and transitional cell carcinoma (TCC) of bladder are the 2 most common malignancies in the male adult urogenital system. Epigenetic gene silencing, particularly tumor suppressor genes, has become a new area of cancer research. Agents such as deoxyribonucleic acid methyltransferase inhibitors or histone deacetylase inhibitors are epigenetic modifiers that can restore gene expression and alter the malignant phenotype of cancer. They provide a new therapeutic avenue for prostate cancer and TCC. It is also likely that combination regimens using epigenetic modifiers with other classes of agents may have higher therapeutic efficacy for prostate cancer and TCC, especially metastatic and/or refractory cases. We review current knowledge of epigenetic event in prostate cancer and TCC, and discuss the possible clinical implications for these 2 diseases.


Assuntos
Carcinoma de Células de Transição/terapia , Terapia Genética , Inibidores de Histona Desacetilases , Neoplasias da Próstata/terapia , Neoplasias da Bexiga Urinária/terapia , Carcinoma de Células de Transição/genética , Epigênese Genética , Humanos , Masculino , Neoplasias da Próstata/genética , Neoplasias da Bexiga Urinária/genética
19.
Cancer Res ; 63(24): 8680-6, 2003 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-14695181

RESUMO

Coxsackie and adenovirus receptor (CAR) is not only a high-affinity receptor for adenovirus, but also a tumor inhibitor in both prostate and bladder cancer lines. Decreased CAR gene expression is often detected in cancer specimens; however, the mechanism(s) is still unknown. In this study, we cloned the entire CAR gene and characterized the core promoter sequence of the CAR gene. The CAR gene promoter activity correlated with the differential expression of CAR mRNA levels from several urogenital cancer cell lines, indicating that the down-regulation of CAR gene expression is mediated by transcriptional regulation. It is known that epigenetic control, such as DNA methylation and histone acetylation of chromatin structure, dictates gene expression. Data from this study indicate that the activation of the CAR gene promoter is modulated by histone acetylation, but not by DNA methylation, in urogenital cancer cells. Also, a potent cancer chemotherapeutic agent (FR901228), a histone deacetylase inhibitor, was able to induce endogenous CAR gene expression in several urogenital cancer cells. Taken together, epigenetic control of CAR gene underlies the down-regulation of this gene in urogenital cancers.


Assuntos
Carcinoma de Células de Transição/genética , Regulação Neoplásica da Expressão Gênica , Receptores Virais/genética , Neoplasias da Bexiga Urinária/genética , Sequência de Bases , Carcinoma de Células de Transição/metabolismo , Linhagem Celular Tumoral , Clonagem Molecular , Proteína de Membrana Semelhante a Receptor de Coxsackie e Adenovirus , Humanos , Dados de Sequência Molecular , Regiões Promotoras Genéticas , Receptores Virais/biossíntese , Neoplasias da Bexiga Urinária/metabolismo
20.
Cancer Res ; 64(4): 1425-30, 2004 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-14973053

RESUMO

Laminin-5 (LN5) anchors epithelial cells to the underlying basement membrane, and it is encoded by three distinct genes: LAMA3, LAMB3, and LAMC2. To metastasize and grow, cancer cells must invade and destroy the basement membrane. Our previous work has shown that epigenetic inactivation is a major mechanism of silencing LN5 genes in lung cancers. We extended our methylation studies to resected bladder tumors (n = 128) and exfoliated cell samples (bladder washes and voided urine; n = 71) and correlated the data with clinicopathologic findings. Nonmalignant urothelium had uniform expression of LN5 genes and lacked methylation. The methylation frequencies for LN5 genes in tumors were 21-45%, and there was excellent concordance between methylation in tumors and corresponding exfoliated cells. Methylation of LAMA3 and LAMB3 and the methylation index were correlated significantly with several parameters of poor prognosis (tumor grade, growth pattern, muscle invasion, tumor stage, and ploidy pattern), whereas methylation of LAMC2 and methylation index were associated with shortened patient survival. Of particular interest, methylation frequencies of LAMA3 helped to distinguish invasive (72%) from noninvasive (12%) tumors. These results suggest that methylation of LN5 genes has potential clinical applications in bladder cancers.


Assuntos
Metilação de DNA , Laminina/genética , Regiões Promotoras Genéticas , Neoplasias da Bexiga Urinária/genética , Linhagem Celular Tumoral , Humanos , Invasividade Neoplásica , Metástase Neoplásica , Prognóstico , Fatores de Risco , Neoplasias da Bexiga Urinária/patologia
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