Your browser doesn't support javascript.
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 3.505
Filtrar
1.
N Engl J Med ; 381(25): 2416-2428, 2019 12 19.
Artigo em Inglês | MEDLINE | ID: mdl-31851799

RESUMO

BACKGROUND: Olaparib has shown significant clinical benefit as maintenance therapy in women with newly diagnosed advanced ovarian cancer with a BRCA mutation. The effect of combining maintenance olaparib and bevacizumab in patients regardless of BRCA mutation status is unknown. METHODS: We conducted a randomized, double-blind, international phase 3 trial. Eligible patients had newly diagnosed, advanced, high-grade ovarian cancer and were having a response after first-line platinum-taxane chemotherapy plus bevacizumab. Patients were eligible regardless of surgical outcome or BRCA mutation status. Patients were randomly assigned in a 2:1 ratio to receive olaparib tablets (300 mg twice daily) or placebo for up to 24 months; all the patients received bevacizumab at a dose of 15 mg per kilogram of body weight every 3 weeks for up to 15 months in total. The primary end point was the time from randomization until investigator-assessed disease progression or death. RESULTS: Of the 806 patients who underwent randomization, 537 were assigned to receive olaparib and 269 to receive placebo. After a median follow-up of 22.9 months, the median progression-free survival was 22.1 months with olaparib plus bevacizumab and 16.6 months with placebo plus bevacizumab (hazard ratio for disease progression or death, 0.59; 95% confidence interval [CI], 0.49 to 0.72; P<0.001). The hazard ratio (olaparib group vs. placebo group) for disease progression or death was 0.33 (95% CI, 0.25 to 0.45) in patients with tumors positive for homologous-recombination deficiency (HRD), including tumors that had BRCA mutations (median progression-free survival, 37.2 vs. 17.7 months), and 0.43 (95% CI, 0.28 to 0.66) in patients with HRD-positive tumors that did not have BRCA mutations (median progression-free survival, 28.1 vs. 16.6 months). Adverse events were consistent with the established safety profiles of olaparib and bevacizumab. CONCLUSIONS: In patients with advanced ovarian cancer receiving first-line standard therapy including bevacizumab, the addition of maintenance olaparib provided a significant progression-free survival benefit, which was substantial in patients with HRD-positive tumors, including those without a BRCA mutation. (Funded by ARCAGY Research and others; PAOLA-1 ClinicalTrials.gov number, NCT02477644.).


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Bevacizumab/administração & dosagem , Neoplasias Ovarianas/tratamento farmacológico , Ftalazinas/administração & dosagem , Piperazinas/administração & dosagem , Inibidores de Poli(ADP-Ribose) Polimerases/uso terapêutico , Adulto , Idoso , Idoso de 80 Anos ou mais , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Bevacizumab/efeitos adversos , Terapia Combinada , Método Duplo-Cego , Feminino , Humanos , Quimioterapia de Manutenção , Pessoa de Meia-Idade , Neoplasias Ovarianas/mortalidade , Neoplasias Ovarianas/cirurgia , Ftalazinas/efeitos adversos , Piperazinas/efeitos adversos , Inibidores de Poli(ADP-Ribose) Polimerases/efeitos adversos , Intervalo Livre de Progressão , Qualidade de Vida
2.
Presse Med ; 48(10): 1092-1100, 2019 Oct.
Artigo em Francês | MEDLINE | ID: mdl-31706893

RESUMO

In France, breast cancer is the most common cancer among women and the leading cause of cancer deaths. Identifying women with a "high" or "very high" breast cancer risk, according the terminology of the Haute Autorité de Santé 2014 guidelines, is essential to offer them special cares in term of screening and prevention. Women genetically predisposed have a very high risk of breast cancer. During the oncogenetic specialist consultation, familial and personal history of cancer is taken into account to evaluate the risk of hereditary Breast/Ovarian syndrome and thus the need of a genetic screening. In 2017, a list of 13 genes involved in hereditary ovarian or breast cancer has been established in France (Genetic and Cancer Group - Unicancer). Women carrying a BRCA1, BRCA2, PALB2, TP53, CDH1, PTEN mutation have a higher risk of breast cancer and are considered as "high risk". Therefore, medical breast surveillance similar to carriers of BRCA1/BRCA2 mutation is recommended for these patients (INCa guidelines 2017). However a mutation in one of those genes is only identified in approximatively 10 % of the screened families. The oncogenetic specialist's assessment distinguishes families in which women remain at a "high" risk of breast cancer (HAS 2014 for screening) from those where women have a "very high" risk (INCa guidelines 2017 for screening and prevention).


Assuntos
Neoplasias da Mama/genética , Predisposição Genética para Doença , Mutação , Fatores Etários , Antígenos CD/genética , Neoplasias da Mama/diagnóstico , Neoplasias da Mama/terapia , Neoplasias da Mama Masculina/genética , Caderinas/genética , Saúde da Família , Proteína do Grupo de Complementação N da Anemia de Fanconi/genética , Feminino , França , Genes BRCA1 , Genes BRCA2 , Genes p53 , Testes Genéticos , Síndrome do Hamartoma Múltiplo/genética , Humanos , Síndrome de Li-Fraumeni/genética , Masculino , Neoplasias Ovarianas/genética , Inibidores de Poli(ADP-Ribose) Polimerases/uso terapêutico , Gravidez , Mastectomia Profilática , Fatores de Risco , Nanomedicina Teranóstica , Neoplasias de Mama Triplo Negativas/genética
3.
Inorg Chem ; 58(23): 16279-16291, 2019 Dec 02.
Artigo em Inglês | MEDLINE | ID: mdl-31738050

RESUMO

Many clinical trials using combinations of platinum drugs and PARP-1 inhibitors (PARPi) have been carried out, with the hope that such combinations will lead to enhanced therapeutic outcomes against tumors. Herein, we obtained seven potential PARPi with structural diversity and then conjugated them with cisplatin-based platinum(IV) complexes. Both the synthesized PARPi ligands and PARPi-Pt conjugates [PARPi-Pt(IV)] show inhibitory effects against PARP-1's catalytic activity. The PARPi-Pt(IV) conjugates are cytotoxic in a panel of human cancer cell lines, and the leading ones display the ability to overcome cisplatin resistance. A mechanistic investigation reveals that the representative PARPi-Pt(IV) conjugates efficiently enter cells, bind to genomic DNA, disturb cell cycle distribution, and induce apoptotic cell death in both cisplatin-sensitive and -resistant cells. Our study provides a strategy to improve the cytotoxicity of platinum(IV)-based anticancer complexes and overcome cisplatin resistance by using a small-molecule anticancer complex that simultaneously damages DNA and inhibits PARP.


Assuntos
Antineoplásicos/farmacologia , Compostos Organoplatínicos/farmacologia , Inibidores de Poli(ADP-Ribose) Polimerases/farmacologia , Poli(ADP-Ribose) Polimerases/metabolismo , Antineoplásicos/síntese química , Antineoplásicos/química , Apoptose/efeitos dos fármacos , Ciclo Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Cisplatino/farmacologia , Relação Dose-Resposta a Droga , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Estrutura Molecular , Compostos Organoplatínicos/síntese química , Compostos Organoplatínicos/química , Inibidores de Poli(ADP-Ribose) Polimerases/síntese química , Inibidores de Poli(ADP-Ribose) Polimerases/química , Relação Estrutura-Atividade
4.
Nucleic Acids Res ; 47(16): 8502-8520, 2019 09 19.
Artigo em Inglês | MEDLINE | ID: mdl-31616951

RESUMO

Microrchidia family CW-type zinc finger 2 (MORC2) is a newly identified chromatin remodeling enzyme with an emerging role in DNA damage response (DDR), but the underlying mechanism remains largely unknown. Here, we show that poly(ADP-ribose) polymerase 1 (PARP1), a key chromatin-associated enzyme responsible for the synthesis of poly(ADP-ribose) (PAR) polymers in mammalian cells, interacts with and PARylates MORC2 at two residues within its conserved CW-type zinc finger domain. Following DNA damage, PARP1 recruits MORC2 to DNA damage sites and catalyzes MORC2 PARylation, which stimulates its ATPase and chromatin remodeling activities. Mutation of PARylation residues in MORC2 results in reduced cell survival after DNA damage. MORC2, in turn, stabilizes PARP1 through enhancing acetyltransferase NAT10-mediated acetylation of PARP1 at lysine 949, which blocks its ubiquitination at the same residue and subsequent degradation by E3 ubiquitin ligase CHFR. Consequently, depletion of MORC2 or expression of an acetylation-defective PARP1 mutant impairs DNA damage-induced PAR production and PAR-dependent recruitment of DNA repair proteins to DNA lesions, leading to enhanced sensitivity to genotoxic stress. Collectively, these findings uncover a previously unrecognized mechanistic link between MORC2 and PARP1 in the regulation of cellular response to DNA damage.


Assuntos
Proteínas de Ciclo Celular/genética , Cromatina/metabolismo , Reparo do DNA , Proteínas de Neoplasias/genética , Poli(ADP-Ribose) Polimerase-1/genética , Proteínas de Ligação a Poli-ADP-Ribose/genética , Processamento de Proteína Pós-Traducional , Fatores de Transcrição/genética , Ubiquitina-Proteína Ligases/genética , Acetilação/efeitos dos fármacos , Proteínas de Ciclo Celular/metabolismo , Linhagem Celular Tumoral , Cromatina/química , Cromatina/efeitos dos fármacos , Montagem e Desmontagem da Cromatina/efeitos dos fármacos , Dano ao DNA , Células HEK293 , Humanos , Mutação , Acetiltransferase N-Terminal E/genética , Acetiltransferase N-Terminal E/metabolismo , Proteínas de Neoplasias/metabolismo , Ftalazinas/farmacologia , Piperazinas/farmacologia , Poli(ADP-Ribose) Polimerase-1/antagonistas & inibidores , Poli(ADP-Ribose) Polimerase-1/metabolismo , Poli Adenosina Difosfato Ribose/metabolismo , Inibidores de Poli(ADP-Ribose) Polimerases/farmacologia , Proteínas de Ligação a Poli-ADP-Ribose/metabolismo , Proteólise/efeitos dos fármacos , Transdução de Sinais , Fatores de Transcrição/metabolismo , Ubiquitina-Proteína Ligases/metabolismo , Ubiquitinação/efeitos dos fármacos
5.
EMBO J ; 38(21): e103479, 2019 10 04.
Artigo em Inglês | MEDLINE | ID: mdl-31633196

RESUMO

A new study reveals that leukemia stem cells (LSCs) in acute myeloid leukemia downregulate natural killer cell-activating receptor ligands to evade immune surveillance via the transcriptional co-factor PARP1. The inhibition of PARP1 sensitizes LSCs to immunotherapy, highlighting its potential as a therapeutic target.


Assuntos
Leucemia Mieloide Aguda , Subfamília K de Receptores Semelhantes a Lectina de Células NK , Humanos , Evasão da Resposta Imune , Imunoterapia , Ligantes , Células-Tronco Neoplásicas , Inibidores de Poli(ADP-Ribose) Polimerases
6.
Cancer Treat Rev ; 80: 101909, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31629204

RESUMO

OBJECTIVE: This meta-analysis investigated the effectiveness of PARP inhibitors (PARPis) as maintenance treatment in platinum sensitive recurrent ovarian cancer (ROC), stratifying results based on BRCA mutational status into five different categories: whole population, germ-line BRCA mutated patients, somatic BRCA mutated patients, HRD patients and wild type population. METHODS: PubMed, Medline, Scopus, EMBASE and clinicaltrials.gov, as well as meeting proceedings were searched for eligible studies that described RCTs testing the efficacy of PARPis as maintenance treatment in platinum sensitive ROC. Data were extracted independently and analysed using RevMan statistical software version 5.3. Primary end-point was progression free survival (PFS). RESULTS: The analysis confirmed the positive effect of PARPis in patients with platinum sensitive ROC in case of germinal or somatic BRCA mutations. Specifically, HR for PFS was 0.26, 95% CI 0.21-0.31, p < 0.00001 for the mutation of BRCA gene and 0.24, 95%, CI 0.12-0.48, p < 0.0001 for the somatic alteration. In addition, in the HRD population, studies that analysed the efficacy of PARPis  reported a PFS improvement with HR 0.34, 95% CI 0.26-0.43, p < 0.00001. Finally, our analysis confirms the role of these drugs in prolonging PFS in the whole population with HR 0.36, 95% CI 0.32-0.42, p < 0.00001, although to a lesser extent, with a significant improvement even in wild type cancers with HR 0.49, 95%, CI 0.41-0.59, p < 0.00001). CONCLUSIONS: PARPis are effective regardless of BRCA mutational status. Future investigations are necessary to explore the use of different PARPis as monotherapy, comparing them among each other in terms of efficacy and toxicity, and exploring their potential re-use.


Assuntos
Genes BRCA1 , Genes BRCA2 , Mutação em Linhagem Germinativa , Recidiva Local de Neoplasia/tratamento farmacológico , Recidiva Local de Neoplasia/genética , Neoplasias Ovarianas/tratamento farmacológico , Neoplasias Ovarianas/genética , Inibidores de Poli(ADP-Ribose) Polimerases/administração & dosagem , Feminino , Humanos , Quimioterapia de Manutenção , Ensaios Clínicos Controlados Aleatórios como Assunto
7.
Cancer Discov ; 9(10): 1340-1342, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31575562

RESUMO

Effective options are limited for patients with small-cell lung cancer who develop progressive disease during or after etoposide plus platinum-based therapy. In this issue of Cancer Discovery, Farago and colleagues highlight the data for temozolomide plus olaparib in this patient population and demonstrate the potential to accelerate biomarker discovery through co-clinical trials utilizing patient-derived xenografts.See related article by Farago et al., p. 1372.


Assuntos
Neoplasias Pulmonares , Inibidores de Poli(ADP-Ribose) Polimerases , Animais , Biomarcadores , Linhagem Celular Tumoral , Xenoenxertos , Humanos , Recidiva Local de Neoplasia , Ftalazinas , Piperazinas , Temozolomida , Ensaios Antitumorais Modelo de Xenoenxerto
8.
Cancer Sci ; 110(11): 3543-3552, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31541611

RESUMO

Poly ADP-ribose polymerase inhibitors (PARPi) have shown promising therapeutic efficacy in triple-negative breast cancer (TNBC) patients. However, resistance ultimately develops, preventing a curative effect from being attained. Extensive investigations have indicated the diversity in the mechanisms underlying the PARPi sensitivity of breast cancer. In this study, we found that DNA damage binding protein 2 (DDB2), a DNA damage-recognition factor, could protect TNBC cells from PARPi by regulating DNA double-strand break repair through the homologous recombination pathway, whereas the depletion of DDB2 sensitizes TNBC cells to PARPi. Furthermore, we found that DDB2 was able to stabilize Rad51 by physical association and disrupting its ubiquitination pathway-induced proteasomal degradation. These findings highlight an essential role of DDB2 in modulating homologous recombination pathway activity and suggest a promising therapeutic target for TNBC.


Assuntos
Quebras de DNA de Cadeia Dupla , Proteínas de Ligação a DNA/metabolismo , Inibidores de Poli(ADP-Ribose) Polimerases/farmacologia , Rad51 Recombinase/metabolismo , Reparo de DNA por Recombinação , Neoplasias de Mama Triplo Negativas/tratamento farmacológico , Neoplasias de Mama Triplo Negativas/metabolismo , Linhagem Celular Tumoral , Reparo do DNA , Proteínas de Ligação a DNA/deficiência , Resistencia a Medicamentos Antineoplásicos , Feminino , Humanos , Proteínas de Neoplasias/metabolismo , Ubiquitinação
9.
N Engl J Med ; 381(25): 2391-2402, 2019 12 19.
Artigo em Inglês | MEDLINE | ID: mdl-31562799

RESUMO

BACKGROUND: Niraparib, an inhibitor of poly(adenosine diphosphate [ADP]-ribose) polymerase (PARP), has been associated with significantly increased progression-free survival among patients with recurrent ovarian cancer after platinum-based chemotherapy, regardless of the presence or absence of BRCA mutations. The efficacy of niraparib in patients with newly diagnosed advanced ovarian cancer after a response to first-line platinum-based chemotherapy is unknown. METHODS: In this randomized, double-blind, phase 3 trial, we randomly assigned patients with newly diagnosed advanced ovarian cancer in a 2:1 ratio to receive niraparib or placebo once daily after a response to platinum-based chemotherapy. The primary end point was progression-free survival in patients who had tumors with homologous-recombination deficiency and in those in the overall population, as determined on hierarchical testing. A prespecified interim analysis for overall survival was conducted at the time of the primary analysis of progression-free survival. RESULTS: Of the 733 patients who underwent randomization, 373 (50.9%) had tumors with homologous-recombination deficiency. Among the patients in this category, the median progression-free survival was significantly longer in the niraparib group than in the placebo group (21.9 months vs. 10.4 months; hazard ratio for disease progression or death, 0.43; 95% confidence interval [CI], 0.31 to 0.59; P<0.001). In the overall population, the corresponding progression-free survival was 13.8 months and 8.2 months (hazard ratio, 0.62; 95% CI, 0.50 to 0.76; P<0.001). At the 24-month interim analysis, the rate of overall survival was 84% in the niraparib group and 77% in the placebo group (hazard ratio, 0.70; 95% CI, 0.44 to 1.11). The most common adverse events of grade 3 or higher were anemia (in 31.0% of the patients), thrombocytopenia (in 28.7%), and neutropenia (in 12.8%). No treatment-related deaths occurred. CONCLUSIONS: Among patients with newly diagnosed advanced ovarian cancer who had a response to platinum-based chemotherapy, those who received niraparib had significantly longer progression-free survival than those who received placebo, regardless of the presence or absence of homologous-recombination deficiency. (Funded by GlaxoSmithKline; PRIMA/ENGOT-OV26/GOG-3012 ClinicalTrials.gov number, NCT02655016.).


Assuntos
Indazóis/uso terapêutico , Neoplasias Ovarianas/tratamento farmacológico , Piperidinas/uso terapêutico , Inibidores de Poli(ADP-Ribose) Polimerases/uso terapêutico , Administração Oral , Adulto , Idoso , Idoso de 80 Anos ou mais , Antineoplásicos/uso terapêutico , Terapia Combinada , Método Duplo-Cego , Feminino , Humanos , Indazóis/efeitos adversos , Quimioterapia de Manutenção , Pessoa de Meia-Idade , Náusea/induzido quimicamente , Neoplasias Ovarianas/mortalidade , Neoplasias Ovarianas/cirurgia , Piperidinas/efeitos adversos , Inibidores de Poli(ADP-Ribose) Polimerases/efeitos adversos , Intervalo Livre de Progressão , Qualidade de Vida , Análise de Sobrevida
10.
N Engl J Med ; 381(25): 2403-2415, 2019 12 19.
Artigo em Inglês | MEDLINE | ID: mdl-31562800

RESUMO

BACKGROUND: Data are limited regarding the use of poly(adenosine diphosphate [ADP]-ribose) polymerase inhibitors, such as veliparib, in combination with chemotherapy followed by maintenance as initial treatment in patients with high-grade serous ovarian carcinoma. METHODS: In an international, phase 3, placebo-controlled trial, we assessed the efficacy of veliparib added to first-line induction chemotherapy with carboplatin and paclitaxel and continued as maintenance monotherapy in patients with previously untreated stage III or IV high-grade serous ovarian carcinoma. Patients were randomly assigned in a 1:1:1 ratio to receive chemotherapy plus placebo followed by placebo maintenance (control), chemotherapy plus veliparib followed by placebo maintenance (veliparib combination only), or chemotherapy plus veliparib followed by veliparib maintenance (veliparib throughout). Cytoreductive surgery could be performed before initiation or after 3 cycles of trial treatment. Combination chemotherapy was 6 cycles, and maintenance therapy was 30 additional cycles. The primary end point was investigator-assessed progression-free survival in the veliparib-throughout group as compared with the control group, analyzed sequentially in the BRCA-mutation cohort, the cohort with homologous-recombination deficiency (HRD) (which included the BRCA-mutation cohort), and the intention-to-treat population. RESULTS: A total of 1140 patients underwent randomization. In the BRCA-mutation cohort, the median progression-free survival was 34.7 months in the veliparib-throughout group and 22.0 months in the control group (hazard ratio for progression or death, 0.44; 95% confidence interval [CI], 0.28 to 0.68; P<0.001); in the HRD cohort, it was 31.9 months and 20.5 months, respectively (hazard ratio, 0.57; 95 CI, 0.43 to 0.76; P<0.001); and in the intention-to-treat population, it was 23.5 months and 17.3 months (hazard ratio, 0.68; 95% CI, 0.56 to 0.83; P<0.001). Veliparib led to a higher incidence of anemia and thrombocytopenia when combined with chemotherapy as well as of nausea and fatigue overall. CONCLUSIONS: Across all trial populations, a regimen of carboplatin, paclitaxel, and veliparib induction therapy followed by veliparib maintenance therapy led to significantly longer progression-free survival than carboplatin plus paclitaxel induction therapy alone. The independent value of adding veliparib during induction therapy without veliparib maintenance was less clear. (Funded by AbbVie; VELIA/GOG-3005 ClinicalTrials.gov number, NCT02470585.).


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Benzimidazóis/uso terapêutico , Cistadenocarcinoma Seroso/tratamento farmacológico , Neoplasias Ovarianas/tratamento farmacológico , Inibidores de Poli(ADP-Ribose) Polimerases/uso terapêutico , Administração Oral , Adulto , Idoso , Idoso de 80 Anos ou mais , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Benzimidazóis/efeitos adversos , Carboplatina/administração & dosagem , Terapia Combinada , Cistadenocarcinoma Seroso/genética , Cistadenocarcinoma Seroso/cirurgia , Método Duplo-Cego , Feminino , Genes BRCA1 , Genes BRCA2 , Humanos , Análise de Intenção de Tratamento , Quimioterapia de Manutenção , Pessoa de Meia-Idade , Mutação , Neoplasias Ovarianas/genética , Neoplasias Ovarianas/cirurgia , Paclitaxel/administração & dosagem , Inibidores de Poli(ADP-Ribose) Polimerases/efeitos adversos , Intervalo Livre de Progressão , Qualidade de Vida
11.
Mol Cell ; 75(6): 1089-1091, 2019 09 19.
Artigo em Inglês | MEDLINE | ID: mdl-31539506

RESUMO

In this issue of Molecular Cell, Kim et al. (2019) identify small nucleolar RNAs (snoRNAs) as activators of poly(ADP-ribose) (PAR) synthesis, demonstrating that this snoRNA-PAR partnership promotes cancer cell growth independent of DNA repair pathways.


Assuntos
Inibidores de Poli(ADP-Ribose) Polimerases , RNA Nucleolar Pequeno , Poli(ADP-Ribose) Polimerase-1 , Poli(ADP-Ribose) Polimerases , RNA Helicases , Ribossomos
12.
Int J Radiat Biol ; 95(12): 1597-1612, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31490091

RESUMO

Background and purpose: Poly(ADP-ribose)polymerase-1 (PARP1) and DNA-dependent protein kinase (DNA-PK) play key roles in the repair of radiation-induced DNA double strand breaks, but it is unclear which is the preferred therapeutic target in radiotherapy. Here we compare small molecule inhibitors of both as radiosensitizers of head and neck squamous cell carcinoma (HNSCC) cell lines.Methods: Two PARP1 inhibitors (olaparib, veliparib) and two DNA-PK inhibitors (KU57788, IC87361) were tested in 14 HNSCC cell lines and two non-tumorigenic lines (HEK-293 and WI-38/Va-13), with drug exposure for 6 or 24 h post-irradiation, using regrowth assays. For three lines (UT-SCC-54C, -74B, -76B), radiosensitization was also assessed by clonogenic assay under oxia and acute (6 h) anoxia, and for 54C cells under chronic hypoxia (0.2% O2 for 48 h). Relationships between sensitizer enhancement ratios (SER) and gene expression, assessed by RNA sequencing, were evaluated.Results: The inhibitors were minimally cytotoxic in the absence of radiation, with 74B and 54C cells the most sensitive to both olaparib and KU57788. Median SER values for each inhibitor at 1.1 µM were 1.12 (range 1.02-1.24) for olaparib, 1.08 (1.04-1.13) for veliparib, 1.35 (1.10-1.64) for IC87361 and 1.77 (1.41-2.38) for KU57788. The higher SER values for the DNA-PK inhibitors were observed with all cell lines (except HEK-293) and all concentrations tested and were confirmed by clonogenic assay. Radiosensitization by the DNA-PK inhibitors correlated with expression of SLFN11 mRNA. Radiosensitization by IC87361 and olaparib was significantly enhanced under acute anoxia and chronic hypoxia.Conclusions: The DNA-PK inhibitors KU57788 and IC87361 are more effective radiosensitizers than the PARP-1 inhibitors olaparib and veliparib at non-cytotoxic concentrations in HNSCC cell cultures and their activity is enhanced by SLFN11 and hypoxia.


Assuntos
Proteína Quinase Ativada por DNA/antagonistas & inibidores , Proteínas Nucleares/metabolismo , Poli(ADP-Ribose) Polimerase-1/antagonistas & inibidores , Radiossensibilizantes/farmacologia , Carcinoma de Células Escamosas de Cabeça e Pescoço/patologia , Hipóxia Tumoral/efeitos dos fármacos , Hipóxia Tumoral/efeitos da radiação , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Proliferação de Células/efeitos da radiação , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Regulação Neoplásica da Expressão Gênica/efeitos da radiação , Humanos , Inibidores de Poli(ADP-Ribose) Polimerases/farmacologia , Inibidores de Proteínas Quinases/farmacologia , Fatores de Tempo
13.
Gynecol Oncol ; 155(1): 144-150, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31434613

RESUMO

OBJECTIVES: Cervical cancer (CC) remains a major health problem worldwide. Poly (adenosine diphosphate [ADP]-ribose) polymerase (PARP) inhibitors (PARPi) have emerged as a promising class of chemotherapeutics in ovarian cancer. We explored the preclinical in vitro and in vivo activity of olaparib against multiple primary whole exome sequenced (WES) CC cells lines and xenografts. METHODS: Olaparib cell-cycle, apoptosis, homologous-recombination-deficiency (HRD), PARP trapping and cytotoxicity activity was evaluated against 9 primary CC cell lines in vitro. PARP and PAR expression were analyzed by Western blot assays. Finally, olaparib in vivo antitumor activity was tested against CC xenografts. RESULTS: While none of the cell lines demonstrated HRD, three out of 9 (33.3%) primary CC cell lines showed strong PARylation activity and demonstrated high sensitivity to olaparib in vitro treatment (cutoff IC50 values < 2 µM, p = 0.0012). Olaparib suppressed CC cell growth through cell cycle arrest in the G2/M phase and caused apoptosis (p < 0.0001). Olaparib activity in CC involved both PARP enzyme inhibition and trapping. In vivo, olaparib significantly impaired CC xenografts tumor growth (p = 0.0017) and increased overall animal survival (p = 0.008). CONCLUSIONS: A subset of CC primary cell lines is highly responsive to olaparib treatment in vitro and in vivo. High level of PARylation correlated with olaparib preclinical activity and may represent a useful biomarker for the identification of CC patients benefitting the most from PARPi.


Assuntos
Ftalazinas/farmacologia , Piperazinas/farmacologia , Poli(ADP-Ribose) Polimerase-1/metabolismo , Inibidores de Poli(ADP-Ribose) Polimerases/farmacologia , Neoplasias do Colo do Útero/tratamento farmacológico , Neoplasias do Colo do Útero/enzimologia , Adulto , Animais , Apoptose/efeitos dos fármacos , Processos de Crescimento Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Relação Dose-Resposta a Droga , Resistencia a Medicamentos Antineoplásicos , Feminino , Pontos de Checagem da Fase G2 do Ciclo Celular/efeitos dos fármacos , Humanos , Pontos de Checagem da Fase M do Ciclo Celular/efeitos dos fármacos , Camundongos SCID , Pessoa de Meia-Idade , Neoplasias do Colo do Útero/patologia , Ensaios Antitumorais Modelo de Xenoenxerto , Adulto Jovem
16.
Drugs Today (Barc) ; 55(7): 459-467, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31347614

RESUMO

Talazoparib tosylate (BMN-673, Talzenna; Pfizer) is an oral poly [ADP-ribose] polymerase (PARP) inhibitor (PARPi) that has been approved by the U.S. Food and Drug Administration (FDA) and the European Medicines Agency (EMA) for the treatment of germline BRCA-mutated locally advanced or metastatic breast cancer (BC). In preclinical and clinical studies, talazoparib exerted superior efficacy and offered a significant clinical benefit in advanced or metastatic BC patients harboring germline BRCA mutations compared with other PARPi and standard chemotherapy regimens through the concept of synthetic lethality. Thus, this review provides insight into the results of preclinical and clinical studies, highlights the current challenges of talazoparib and suggests innovative approaches to further improve its clinical efficacy and expand the use of talazoparib in advanced BC and/or triple-negative BC treatments beyond BRCA mutations.


Assuntos
Neoplasias da Mama/tratamento farmacológico , Ftalazinas/uso terapêutico , Inibidores de Poli(ADP-Ribose) Polimerases/uso terapêutico , Proteína BRCA1/genética , Neoplasias da Mama/genética , Humanos , Mutação
17.
Nucleic Acids Res ; 47(17): 9132-9143, 2019 09 26.
Artigo em Inglês | MEDLINE | ID: mdl-31329989

RESUMO

Poly(ADP-ribose) polymerases (PARPs) facilitate the repair of DNA single-strand breaks (SSBs). When PARPs are inhibited, unrepaired SSBs colliding with replication forks give rise to cytotoxic double-strand breaks. These are normally rescued by homologous recombination (HR), but, in cells with suboptimal HR, PARP inhibition leads to genomic instability and cell death, a phenomenon currently exploited in the therapy of ovarian cancers in BRCA1/2 mutation carriers. In spite of their promise, resistance to PARP inhibitors (PARPis) has already emerged. In order to identify the possible underlying causes of the resistance, we set out to identify the endogenous source of DNA damage that activates PARPs. We argued that if the toxicity of PARPis is indeed caused by unrepaired SSBs, these breaks must arise spontaneously, because PARPis are used as single agents. We now show that a significant contributor to PARPi toxicity is oxygen metabolism. While BRCA1-depleted or -mutated cells were hypersensitive to the clinically approved PARPi olaparib, its toxicity was significantly attenuated by depletion of OGG1 or MYH DNA glycosylases, as well as by treatment with reactive oxygen species scavengers, growth under hypoxic conditions or chemical OGG1 inhibition. Thus, clinical resistance to PARPi therapy may emerge simply through reduced efficiency of oxidative damage repair.


Assuntos
Proteína BRCA1/genética , DNA Glicosilases/genética , Neoplasias Ovarianas/tratamento farmacológico , Poli(ADP-Ribose) Polimerases/genética , Linhagem Celular Tumoral , Quebras de DNA de Cadeia Simples/efeitos dos fármacos , Dano ao DNA/efeitos dos fármacos , DNA Glicosilases/antagonistas & inibidores , Resistencia a Medicamentos Antineoplásicos/genética , Feminino , Recombinação Homóloga/efeitos dos fármacos , Recombinação Homóloga/genética , Humanos , Neoplasias Ovarianas/genética , Neoplasias Ovarianas/patologia , Oxirredução/efeitos dos fármacos , Ftalazinas/efeitos adversos , Ftalazinas/farmacologia , Piperazinas/efeitos adversos , Piperazinas/farmacologia , Inibidores de Poli(ADP-Ribose) Polimerases/farmacologia , Espécies Reativas de Oxigênio/metabolismo , Mutações Sintéticas Letais/genética
19.
Nature ; 572(7768): 254-259, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31316209

RESUMO

Patients with acute myeloid leukaemia (AML) often achieve remission after therapy, but subsequently die of relapse1 that is driven by chemotherapy-resistant leukaemic stem cells (LSCs)2,3. LSCs are defined by their capacity to initiate leukaemia in immunocompromised mice4. However, this precludes analyses of their interaction with lymphocytes as components of anti-tumour immunity5, which LSCs must escape to induce cancer. Here we demonstrate that stemness and immune evasion are closely intertwined in AML. Using xenografts of human AML as well as syngeneic mouse models of leukaemia, we show that ligands of the danger detector NKG2D-a critical mediator of anti-tumour immunity by cytotoxic lymphocytes, such as NK cells6-9-are generally expressed on bulk AML cells but not on LSCs. AML cells with LSC properties can be isolated by their lack of expression of NKG2D ligands (NKG2DLs) in both CD34-expressing and non-CD34-expressing cases of AML. AML cells that express NKG2DLs are cleared by NK cells, whereas NKG2DL-negative leukaemic cells isolated from the same individual escape cell killing by NK cells. These NKG2DL-negative AML cells show an immature morphology, display molecular and functional stemness characteristics, and can initiate serially re-transplantable leukaemia and survive chemotherapy in patient-derived xenotransplant models. Mechanistically, poly-ADP-ribose polymerase 1 (PARP1) represses expression of NKG2DLs. Genetic or pharmacologic inhibition of PARP1 induces NKG2DLs on the LSC surface but not on healthy or pre-leukaemic cells. Treatment with PARP1 inhibitors, followed by transfer of polyclonal NK cells, suppresses leukaemogenesis in patient-derived xenotransplant models. In summary, our data link the LSC concept to immune escape and provide a strong rationale for targeting therapy-resistant LSCs by PARP1 inhibition, which renders them amenable to control by NK cells in vivo.


Assuntos
Evasão da Resposta Imune , Leucemia Mieloide Aguda/patologia , Subfamília K de Receptores Semelhantes a Lectina de Células NK/metabolismo , Células-Tronco Neoplásicas/imunologia , Células-Tronco Neoplásicas/patologia , Evasão Tumoral , Animais , Antígenos CD34/metabolismo , Modelos Animais de Doenças , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Feminino , Humanos , Células Matadoras Naturais/imunologia , Leucemia Mieloide Aguda/imunologia , Ligantes , Masculino , Camundongos , Células-Tronco Neoplásicas/metabolismo , Poli(ADP-Ribose) Polimerase-1/antagonistas & inibidores , Poli(ADP-Ribose) Polimerase-1/metabolismo , Inibidores de Poli(ADP-Ribose) Polimerases/farmacologia , Ensaios Antitumorais Modelo de Xenoenxerto
20.
Nat Commun ; 10(1): 2910, 2019 07 02.
Artigo em Inglês | MEDLINE | ID: mdl-31266951

RESUMO

PARP inhibitors (PARPis) have clinical efficacy in BRCA-deficient cancers, but not BRCA-intact tumors, including glioblastoma (GBM). We show that MYC or MYCN amplification in patient-derived glioblastoma stem-like cells (GSCs) generates sensitivity to PARPi via Myc-mediated transcriptional repression of CDK18, while most tumors without amplification are not sensitive. In response to PARPi, CDK18 facilitates ATR activation by interacting with ATR and regulating ATR-Rad9/ATR-ETAA1 interactions; thereby promoting homologous recombination (HR) and PARPi resistance. CDK18 knockdown or ATR inhibition in GSCs suppressed HR and conferred PARPi sensitivity, with ATR inhibitors synergizing with PARPis or sensitizing GSCs. ATR inhibitor VE822 combined with PARPi extended survival of mice bearing GSC-derived orthotopic tumors, irrespective of PARPi-sensitivity. These studies identify a role of CDK18 in ATR-regulated HR. We propose that combined blockade of ATR and PARP is an effective strategy for GBM, even for low-Myc GSCs that do not respond to PARPi alone, and potentially other PARPi-refractory tumors.


Assuntos
Proteínas Mutadas de Ataxia Telangiectasia/genética , Quinases Ciclina-Dependentes/genética , Resistencia a Medicamentos Antineoplásicos , Glioblastoma/metabolismo , Recombinação Homóloga , Inibidores de Poli(ADP-Ribose) Polimerases/administração & dosagem , Proteínas Proto-Oncogênicas c-myc/metabolismo , Animais , Antígenos de Superfície/genética , Antígenos de Superfície/metabolismo , Proteínas Mutadas de Ataxia Telangiectasia/metabolismo , Proteínas de Ciclo Celular/genética , Proteínas de Ciclo Celular/metabolismo , Quinases Ciclina-Dependentes/metabolismo , Feminino , Glioblastoma/tratamento farmacológico , Glioblastoma/genética , Humanos , Camundongos , Camundongos SCID , Proteína Proto-Oncogênica N-Myc/genética , Proteína Proto-Oncogênica N-Myc/metabolismo , Células-Tronco Neoplásicas/metabolismo , Poli(ADP-Ribose) Polimerase-1/genética , Poli(ADP-Ribose) Polimerase-1/metabolismo , Ligação Proteica , Proteínas Proto-Oncogênicas c-myc/genética , Ensaios Antitumorais Modelo de Xenoenxerto
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA