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1.
Invest New Drugs ; 39(1): 142-151, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-32556884

RESUMO

Temozolomide (TMZ) generates DNA adducts that are repaired by direct DNA and base excision repair mechanisms. Methoxyamine (MX, TRC-102) potentiates TMZ activity by binding to apurinic and apyrimidinic (AP) sites after removal of N3-methyladenine and N7-methylguanine, inhibiting site recognition of AP endonuclease. We conducted a phase I trial to determine the maximum tolerated dose and dose-limiting toxicities (DLTs) of intravenous MX when given with oral TMZ. Patients with advanced solid tumors and progression on standard treatment were enrolled to a standard 3 + 3 dose escalation trial assessing escalating doses of TMZ and MX. Tumor response was assessed per RECIST and adverse events (AEs) by CTCAEv3. Pharmacokinetics (PK) of MX and COMET assays on peripheral blood mononuclear cells were performed. 38 patients were enrolled-median age 59.5 years (38-76), mean number of cycles 2.9 [1-13]. No DLTs were observed. Cycle 1 grade 3 AEs included fatigue, lymphopenia, anemia, INR, leukopenia, neutropenia, allergic reaction, constipation, psychosis and paranoia. Cycle 2-13 grade 4 AEs included thrombocytopenia and confusion. A partial response was seen in 1 patient with a pancreatic neuroendocrine tumor (PNET) and six additional patients, each with different tumor types, demonstrated prolonged stable disease. MX PK was linear with dose and was not affected by concomitant TMZ. TMZ 200 mg/m2 daily × 5 may be safely administered with MX 150 mg/m2 intravenously once on day 1 with minimal toxicity. Further studies assessing this drug combination in select tumor types where temozolomide has activity may be warranted.


Assuntos
Antineoplásicos Alquilantes/uso terapêutico , Hidroxilaminas/uso terapêutico , Neoplasias/tratamento farmacológico , Temozolomida/uso terapêutico , Adulto , Idoso , Antineoplásicos Alquilantes/administração & dosagem , Antineoplásicos Alquilantes/efeitos adversos , Antineoplásicos Alquilantes/farmacocinética , Protocolos de Quimioterapia Combinada Antineoplásica/farmacocinética , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Área Sob a Curva , Reparo do DNA/efeitos dos fármacos , Relação Dose-Resposta a Droga , Sinergismo Farmacológico , Feminino , Meia-Vida , Humanos , Hidroxilaminas/administração & dosagem , Hidroxilaminas/efeitos adversos , Hidroxilaminas/farmacocinética , Masculino , Dose Máxima Tolerável , Taxa de Depuração Metabólica , Pessoa de Meia-Idade , Temozolomida/efeitos adversos , Temozolomida/farmacocinética
2.
Oncologist ; 18(10): 1091-2, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-24072218

RESUMO

BACKGROUND: Src, EphA2, and platelet-derived growth factor receptors α and ß are dysregulated in pancreatic ductal adenocarcinoma (PDAC). METHODS: Dasatinib is an oral multitarget tyrosine kinase inhibitor that targets BCR-ABL, c-Src, c-KIT, platelet-derived growth factor receptor ß, and EphA2. We conducted a phase II, single-arm study of dasatinib as first-line therapy in patients with metastatic PDAC. METHODS: Dasatinib (100 mg twice a day, later reduced to 70 mg twice a day because of toxicities) was orally administered continuously on a 28-day cycle. The primary endpoint was overall survival (OS). Response was measured using the Response Evaluation Criteria in Solid Tumors. Circulating tumor cells (CTCs) were also collected. RESULTS: Fifty-one patients enrolled in this study. The median OS was 4.7 months (95% confidence interval [CI]: 2.8-6.9 months). Median progression-free survival was 2.1 months (95% CI: 1.6-3.2 months). In 34 evaluable patients, the best response achieved was stable disease in 10 patients (29.4%). One patient had stable disease while on treatment for 20 months. The most common nonhematologic toxicities were fatigue and nausea. Edema and pleural effusions occurred in 29% and 6% of patients, respectively. The number of CTCs did not correlate with survival. CONCLUSION: Single-agent dasatinib does not have clinical activity in metastatic PDAC.


Assuntos
Adenocarcinoma/tratamento farmacológico , Metástase Neoplásica/tratamento farmacológico , Neoplasias Pancreáticas/tratamento farmacológico , Pirimidinas/administração & dosagem , Tiazóis/administração & dosagem , Adenocarcinoma/epidemiologia , Adenocarcinoma/patologia , Dasatinibe , Intervalo Livre de Doença , Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos/patologia , Humanos , Estimativa de Kaplan-Meier , Metástase Neoplásica/patologia , Células Neoplásicas Circulantes , Neoplasias Pancreáticas/epidemiologia , Neoplasias Pancreáticas/patologia , Inibidores de Proteínas Quinases/administração & dosagem , Pirimidinas/efeitos adversos , Tiazóis/efeitos adversos
3.
Invest New Drugs ; 31(5): 1244-50, 2013 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-23553066

RESUMO

INTRODUCTION: This study aimed to assess the safety and tolerability of the multitargeted tyrosine kinase inhibitor, vandetanib (V), in combination with two chemotherapeutic agents, oxaliplatin (O) and docetaxel (D) in advanced gastroesophageal (GE) cancer. METHODS: This was a Phase I study (NCT00732745) with a standard 3+3 dose escalation design. The primary aim was to determine the optimal dose of the combination of vandetanib and OD chemotherapy. RESULTS: Initial treatment for the first cohort consisted of oxaliplatin at 100 mg/m2 on day 1, docetaxel at 35 mg/m2 on days 1 and 8 and vandetanib 100 mg PO daily of 21-day treatment cycles. As dose limiting toxicity (DLT) was reached in 2 out of 3 patients in cohort 1 (one grade 3 and one grade 4 diarrhea with dehydration), 6 patients were treated then at dose level -1 (O 80 mg/m2 on day 1, D 30 mg/m2 on days 1 and 8, V 100 mg PO daily days 1-21) in which no further DLTs were observed. This dose was established as maximum tolerated dose and is the recommended phase 2 dose. 8 out of 9 enrolled patients had adenocarcinoma. At dose level 1, 1 of the 3 patients had a documented partial response and 2 patients had stable disease. At dose level -1, 1 of 6 patients achieved a complete response, 2 of 6 patients had stable disease, and 3 of 6 patients had progressive disease. CONCLUSIONS: Vandetanib added to oxaliplatin and docetaxel showed manageable toxicity and limited activity in advanced GE cancer.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/administração & dosagem , Neoplasias Gastrointestinais/tratamento farmacológico , Adulto , Idoso , Antineoplásicos/administração & dosagem , Antineoplásicos/efeitos adversos , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Docetaxel , Relação Dose-Resposta a Droga , Humanos , Masculino , Dose Máxima Tolerável , Pessoa de Meia-Idade , Compostos Organoplatínicos/administração & dosagem , Compostos Organoplatínicos/efeitos adversos , Oxaliplatina , Piperidinas/administração & dosagem , Piperidinas/efeitos adversos , Inibidores de Proteínas Quinases/administração & dosagem , Inibidores de Proteínas Quinases/efeitos adversos , Quinazolinas/administração & dosagem , Quinazolinas/efeitos adversos , Receptores de Fatores de Crescimento do Endotélio Vascular/antagonistas & inibidores , Taxoides/administração & dosagem , Taxoides/efeitos adversos
4.
Cancer Chemother Pharmacol ; 70(5): 755-61, 2012 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-22875080

RESUMO

PURPOSE: To determine the safety, the maximal tolerated dose, and to assess for any clinical activity of pomalidomide given to patients with advanced solid tumors. PATIENTS AND METHODS: Patients with incurable solid tumors were enrolled. Two different dosing schedules were explored. In Cohort A patients were given pomalidomide once daily for 21 days followed by a 7 day rest. For Cohort B additional patients were recruited to receive pomalidomide given once daily for 28 consecutive days. Dose-limiting toxicity was defined as ≥grade 3 non-hematological toxicity that occurs during cycle 1 and that does not resolve to ≤grade 1 by day 35. Subjects must have received optimal symptomatic treatment for ≥grade 3 nausea, vomiting, or diarrhea to be considered a DLT. Grade 4 transaminitis was considered to be a DLT while grade 3 transaminitis must be present >7 days to be a DLT. Grade 3 febrile neutropenia was considered a DLT. Grade 4 neutropenia, without a fever, was a DLT if the neutropenia did not improve to ≤grade 1 by day 35 of cycle one. Platelet count ≤25,000/mm(3) must improve to ≥75,000/mm(3) by day 35 of cycle one in order not to be considered a DLT. If a patient did not complete one cycle of therapy, for reasons other than a DLT, a replacement subject was added to the same cohort level. RESULTS: A total of 40 patients were enrolled. In Cohort A, three patients received pomalidomide at 5 mg daily without any significant toxicity. Two patients in the 10 mg cohort experienced dose-limiting toxicities of two episodes of grade 3 dyspnea and one grade 4 neutropenia. Six patients were then enrolled at the 7 mg daily of pomalidomide, and no dose-limiting events were observed. In Cohort B, 29 patients were enrolled and the maximal tolerated dose was 4 mg once daily. Stable disease in a variety of tumors was observed. CONCLUSIONS: Pomalidomide was well tolerated and the recommended phase II dosing schedules are 7 mg daily given for 21 days followed by a 7-day rest or pomalidomide 4 mg given on an uninterrupted daily schedule.


Assuntos
Antineoplásicos/administração & dosagem , Fatores Imunológicos/administração & dosagem , Neoplasias/tratamento farmacológico , Talidomida/análogos & derivados , Adulto , Idoso , Idoso de 80 Anos ou mais , Antineoplásicos/efeitos adversos , Antineoplásicos/uso terapêutico , Estudos de Coortes , Relação Dose-Resposta a Droga , Esquema de Medicação , Feminino , Humanos , Fatores Imunológicos/efeitos adversos , Fatores Imunológicos/uso terapêutico , Masculino , Dose Máxima Tolerável , Pessoa de Meia-Idade , Neoplasias/patologia , Talidomida/administração & dosagem , Talidomida/efeitos adversos , Talidomida/uso terapêutico , Resultado do Tratamento , Adulto Jovem
5.
Cancer Chemother Pharmacol ; 70(4): 547-53, 2012 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-22868341

RESUMO

PURPOSE: Combining cytotoxic agents with bevacizumab has yielded significant benefits in a number of solid tumors. Combining small-molecule kinase inhibitors of VEGFR with chemotherapy has yet to demonstrate clinical benefit. The dose, schedule and agents used may be critical to the development of this combinatorial therapy. METHODS: We performed a phase I trial of sunitinib and gemcitabine in patients with advanced solid tumor malignancies based on strong preclinical rationale. RESULTS: Two different MTDs were determined. The schedule of gemcitabine 800 mg/m(2) on days 1, 8, 15 and sunitinib 25 mg daily was considered to be a MTD. However, omission of day 15 gemcitabine was common, and thus, a second MTD of gemcitabine of 675 mg/m(2) on days 1 and 8 with sunitinib 25 mg daily was determined to be the recommended phase II dose. Grade 4 neutropenia and thrombocytopenia occurred in 33 and 6 %, respectively. Grade 3/4 non-hematological toxicities were uncommon. Four of 33 patients had a partial response. Another 11 patients had stable disease ranging from 3 to 36 months. Thus, the recommended phase II dose of this combination is gemcitabine 675 mg/m(2) on days 1 and 8 on an every 21-day schedule along with sunitinib 25 mg continuous daily. CONCLUSIONS: This combination is well-tolerated and has significant clinical activity.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Neoplasias/tratamento farmacológico , Adulto , Idoso , Desoxicitidina/administração & dosagem , Desoxicitidina/efeitos adversos , Desoxicitidina/análogos & derivados , Feminino , Humanos , Indóis/administração & dosagem , Indóis/efeitos adversos , Masculino , Dose Máxima Tolerável , Pessoa de Meia-Idade , Pirróis/administração & dosagem , Pirróis/efeitos adversos , Sunitinibe , Gencitabina
6.
AACN Adv Crit Care ; 22(4): 323-34; quiz 335-6, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-22064581

RESUMO

The start of the 21st century has produced advances in cancer care that have improved both survival rates and quality of life for many persons diagnosed with cancer. Targeted therapy has given new hope for controlling cancer as a chronic illness. Alone, or in combination with traditional therapies such as surgery, radiation, and/or chemotherapy, this new form of therapy targets malignant cells, halting tumor growth and the potential metastatic spread of disease. Toxicities are limited, but some are serious and may require intensive care. It is imperative for the experienced critical care nurse to have an understanding of these new treatment options and those on the horizon, as these therapies are the future of cancer care. Whereas in previous decades, patients with cancer may not have survived an intensive care admission for treatment complications or advanced disease, many patients now are recovering from life-threatening events, continuing treatment for their disease, and going on to live meaningful, good-quality lives.


Assuntos
Neoplasias/tratamento farmacológico , Antineoplásicos/efeitos adversos , Antineoplásicos/uso terapêutico , Educação Continuada , Humanos , Neoplasias/fisiopatologia , Qualidade de Vida , Taxa de Sobrevida
7.
Invest New Drugs ; 29(1): 126-30, 2011 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-19774342

RESUMO

Rebeccamycin analog (RA) is an antitumor antibiotic with both topoisomerase I and II inhibiting activity. Topoisomerase inhibitors have demonstrated synergy with platinum agents. We performed a phase I trial of combination RA with oxaliplatin in patients with refractory solid tumors. RA was administered as a 1-hour infusion daily on days 1-5 with oxaliplatin administered on day 5. Cycles were repeated every 21 days. A total of 17 patients were enrolled. The MTD for RA was 80 mg/m(2)/d for five days along with oxaliplatin 130 mg/m(2) on day 5. Myelosuppression was a common occurrence but was mild except in one instance. Dose limiting toxicities included atrial fibrillation and hypophosphatemia. There was evidence of antitumor activity including 3 partial responses in patients with esophageal, gallbladder and hepato-cellular carcinoma; 5 additional patients had stable disease. Thus, the combination of RA and oxaliplatin is both tolerable and has evidence of clinical activity, but given the lack of significant activity for single agent RA across a variety of disease sites, it is unlikely to proceed to phase II development.


Assuntos
Antineoplásicos/uso terapêutico , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Carbazóis/uso terapêutico , Resistencia a Medicamentos Antineoplásicos , Glucosídeos/uso terapêutico , Neoplasias/tratamento farmacológico , Compostos Organoplatínicos/uso terapêutico , Adulto , Idoso , Idoso de 80 Anos ou mais , Antineoplásicos/administração & dosagem , Antineoplásicos/efeitos adversos , Protocolos de Quimioterapia Combinada Antineoplásica/administração & dosagem , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Carbazóis/administração & dosagem , Carbazóis/efeitos adversos , Relação Dose-Resposta a Droga , Feminino , Glucosídeos/administração & dosagem , Glucosídeos/efeitos adversos , Humanos , Masculino , Pessoa de Meia-Idade , Compostos Organoplatínicos/administração & dosagem , Compostos Organoplatínicos/efeitos adversos , Oxaliplatina
9.
Clin Cancer Res ; 15(19): 6277-83, 2009 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-19773375

RESUMO

PURPOSE: Bevacizumab is an antibody against vascular endothelial growth factor; sunitinib is an inhibitor of vascular endothelial growth factor and related receptors. The safety and maximum tolerated dose of sunitinib plus bevacizumab was assessed in this phase I trial. EXPERIMENTAL DESIGN: Patients with advanced solid tumors were treated on a 3+3 trial design. Patients received sunitinib daily (starting dose level, 25 mg) for 4 weeks on followed by 2 weeks off and bevacizumab (starting dose level, 5 mg/kg) on days 1, 15, and 29 of a 42-day cycle. Dose-limiting toxicities during the first 6-week cycle were used to determine the maximum tolerated dose. RESULTS: Thirty-eight patients were enrolled. Patients received a median of 3 cycles of treatment (range, 1-17(+)). There was one dose-limiting toxicity (grade 4 hypertension) at 37.5 mg sunitinib and 5 mg/kg bevacizumab. Grade 3 or greater toxicity was observed in 87% of patients including hypertension (47%), fatigue (24%), thrombocytopenia (18%), proteinuria (13%), and hand-foot syndrome (13%). Dose modifications and delays were common at higher dose levels. No clinical or laboratory evidence of microangiopathic hemolytic anemia was observed. Seven patients had a confirmed Response Evaluation Criteria in Solid Tumors-defined partial response (18%; 95% confidence interval, 8-34%). Nineteen of the 32 patients with a postbaseline scan (59%) had at least some reduction in overall tumor burden (median, 32%; range, 3-73%). CONCLUSIONS: The combination of sunitinib and bevacizumab in patients with advanced solid tumors is feasible, albeit with toxicity at higher dose levels and requiring dose modification with continued therapy. Antitumor activity was observed across multiple solid tumors.


Assuntos
Anticorpos Monoclonais/administração & dosagem , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Indóis/administração & dosagem , Neoplasias/tratamento farmacológico , Pirróis/administração & dosagem , Adulto , Idoso , Idoso de 80 Anos ou mais , Anticorpos Monoclonais/efeitos adversos , Anticorpos Monoclonais Humanizados , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Bevacizumab , Relação Dose-Resposta a Droga , Feminino , Humanos , Indóis/efeitos adversos , Masculino , Dose Máxima Tolerável , Pessoa de Meia-Idade , Neoplasias/patologia , Pirróis/efeitos adversos , Sunitinibe , Resultado do Tratamento , Carga Tumoral/efeitos dos fármacos
10.
Thyroid ; 19(3): 233-40, 2009 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-19265494

RESUMO

BACKGROUND: Fosbretabulin is a novel vascular-disrupting agent that has antitumor activity against anaplastic thyroid cancer (ATC) cell lines, xenografts, and demonstrable efficacy in a phase I trial. This phase II study determined the efficacy and safety of fosbretabulin in patients with advanced ATC and whether fosbretabulin altered the natural history of ATC by virtue of doubling the median survival. A secondary aim evaluated the prognostic value of serum soluble intracellular adhesion molecule-1 (sICAM). METHODS: Twenty-six patients received fosbretabulin 45 mg/m(2) as a 10-minute intravenous infusion on days 1, 8, and 15 of a 28-day cycle. sICAM levels were obtained at baseline, over the first two cycles, and end of therapy. Treatment was continued until disease progression. RESULTS: Fosbretabulin was well tolerated; grade 3 toxicity was observed in nine patients (35%), and grade 4 toxicity in one (4%). QTc prolongation delayed treatment in four causing one to stop treatment. Median survival was 4.7 months with 34% and 23% alive at 6 and 12 months, respectively. Median duration of stable disease in seven patients was 12.3 months (range, 4.4-37.9 months). Baseline serum sICAM levels were measured in 24 patients with a median 253.5 ng/mL. There was a significant difference in event-free survival among tertiles of baseline sICAM levels (p < 0.009). CONCLUSIONS: There were no objective responses seen with single-agent fosbretabulin as administered in this trial, and we did not observe a doubling of survival as our primary endpoint. This is among the largest prospective trials ever conducted for ATC. Fosbretabulin has an acceptable safety profile in patients with advanced ATC, and one-third survived more than 6 months. Despite a small sample size, low baseline sICAM levels were predictive of event-free survival. Further prospective validation of sICAM as a therapeutic biomarker and exploring combination regimens with fosbretabulin are warranted.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Bibenzilas/uso terapêutico , Carcinoma/tratamento farmacológico , Moléculas de Adesão de Célula Nervosa/metabolismo , Compostos Organofosforados/uso terapêutico , Neoplasias da Glândula Tireoide/tratamento farmacológico , Adulto , Idoso , Antineoplásicos/administração & dosagem , Antineoplásicos Fitogênicos/administração & dosagem , Protocolos de Quimioterapia Combinada Antineoplásica/administração & dosagem , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Antígeno CD56 , Carboplatina/administração & dosagem , Carcinoma/patologia , Feminino , Humanos , Estimativa de Kaplan-Meier , Masculino , Pessoa de Meia-Idade , Metástase Neoplásica , Paclitaxel/administração & dosagem , Estilbenos , Sobreviventes , Neoplasias da Glândula Tireoide/patologia , Resultado do Tratamento , Adulto Jovem
11.
Invest New Drugs ; 27(5): 453-60, 2009 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-19011760

RESUMO

PURPOSE: Cytotoxic and anti-angiogenic drugs are efficacious in malignancies. This trial was undertaken to evaluate the toxicity of a novel regimen combining docetaxel and lenalidomide. PATIENTS AND METHODS: Patients with advanced solid tumors were eligible. Docetaxel was administered on day 1, and lenalidomide was given on days 1-14 of each 21-day cycle. Since significant myelosuppression occurred, pegfilgrastim was added on day 2. Dose limiting toxicity (DLT) was defined as >or=grade 3 non-hematologic toxicity, grade 4 neutropenia with fever, or grade 4 anemia or thrombocytopenia. RESULTS: Thirty-three patients were enrolled. DLTs included neutropenia, nausea/vomiting, and dyspnea. Of the evaluable patients, 69% had stable disease, and 3% had partial response. CONCLUSIONS: This regimen was well tolerated and provided stable disease in the majority of advanced cancer patients. The recommended phase II dosing is docetaxel 75 mg/m(2) on day 1, lenalidomide 25 mg on days 1-14, and pegfilgrastim 6 mg on day 2, given every 3 weeks.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Neoplasias/tratamento farmacológico , Adulto , Idoso , Idoso de 80 Anos ou mais , Docetaxel , Relação Dose-Resposta a Droga , Feminino , Humanos , Lenalidomida , Masculino , Dose Máxima Tolerável , Pessoa de Meia-Idade , Prognóstico , Taxoides/administração & dosagem , Talidomida/administração & dosagem , Talidomida/análogos & derivados , Resultado do Tratamento , Adulto Jovem
12.
Invest New Drugs ; 26(4): 355-62, 2008 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-18470481

RESUMO

PURPOSE: Pre-clinical models have demonstrated the benefit of metronomic schedules of cytotoxic chemotherapy combined with anti-angiogenic compounds. This trial was undertaken to determine the toxicity of a low dose regimen using docetaxel and thalidomide. PATIENTS AND METHODS: Patients with advanced solid tumors were enrolled. Thalidomide 100mg twice daily was given with escalating doses of docetaxel from 10 to 30 mg/m(2)/week. One cycle consisted of 12 consecutive weeks of therapy. The maximal tolerated dose (MTD) was defined as the dose of thalidomide along with docetaxel that caused < or =grade 1 non-hematologic or < or =grade 2 hematologic toxicity for cycle one. RESULTS: Twenty-six patients were enrolled. Dose-limiting toxicities (DLTs) were bradycardia, fatigue, fever, hyperbilirubinemia, leukopenia, myocardial infarction, and neutropenia. Prolonged freedom from disease progression was observed in 44.4% of the evaluable patients. CONCLUSIONS: This anti-angiogenic regimen was well tolerated and demonstrated clinical benefit. The recommended phase II dosing schedule is thalidomide 100 mg twice daily with docetaxel 25 mg/m(2)/week.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Neoplasias/tratamento farmacológico , Neovascularização Patológica/tratamento farmacológico , Adulto , Idoso , Inibidores da Angiogênese/administração & dosagem , Inibidores da Angiogênese/efeitos adversos , Inibidores da Angiogênese/uso terapêutico , Protocolos de Quimioterapia Combinada Antineoplásica/administração & dosagem , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Progressão da Doença , Intervalo Livre de Doença , Relação Dose-Resposta a Droga , Feminino , Humanos , Masculino , Dose Máxima Tolerável , Pessoa de Meia-Idade , Neoplasias/fisiopatologia , Neovascularização Patológica/fisiopatologia , Paclitaxel/administração & dosagem , Talidomida/administração & dosagem
13.
Nucleic Acids Res ; 30(20): 4509-18, 2002 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-12384598

RESUMO

N6-methyladenosine (m6A) is present at internal sites in mRNA isolated from all higher eukaryotes, but has not previously been detected in the mRNA of the yeast Saccharomyces cerevisiae. This nucleoside modification occurs only in a sequence- specific context that appears to be conserved across diverse species. The function of this modification is not fully established, but there is some indirect evidence that m6A may play a role in the efficiency of mRNA splicing, transport or translation. The S.cerevisiae gene IME4, which is important for induction of sporulation, is very similar to the human gene MT-A70, which has been shown to be a critical subunit of the human mRNA [N6-adenosine]-methyltransferase. This observation led to the hypothesis that yeast sporulation may be dependent upon methylation of yeast mRNA, mediated by Ime4p. In this study we show that induction of sporulation leads to the appearance of low levels of m6A in yeast mRNA and that this modification requires IME4. Moreover, single amino acid substitutions in the putative catalytic residues of Ime4p lead to severe sporulation defects in a strain whose sporulation ability is completely dependent on this protein. Collectively, these data suggest very strongly that the activation of sporulation by Ime4p is the result of its proposed methyltransferase activity and provide the most direct evidence to date of a physiologic role of m6A in a gene regulatory pathway.


Assuntos
Adenosina/análogos & derivados , Adenosina/biossíntese , Metiltransferases/metabolismo , RNA Fúngico/química , RNA Mensageiro/química , Proteínas de Saccharomyces cerevisiae , Saccharomyces cerevisiae/genética , Fatores de Transcrição , Motivos de Aminoácidos , Sequência de Aminoácidos , Animais , Cromatografia Líquida de Alta Pressão , Sequência Conservada , Proteínas Fúngicas/biossíntese , Proteínas Fúngicas/genética , Genes Fúngicos , Humanos , Cinética , Meiose , Metiltransferases/química , Metiltransferases/genética , Dados de Sequência Molecular , Mutagênese Sítio-Dirigida , Proteínas Nucleares/biossíntese , Proteínas Nucleares/genética , Nucleosídeos/análise , Poliadenilação , RNA Fúngico/metabolismo , RNA Mensageiro/metabolismo , Saccharomyces cerevisiae/enzimologia , Saccharomyces cerevisiae/fisiologia , Homologia de Sequência de Aminoácidos , Esporos Fúngicos/genética
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