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1.
Arch Virol ; 165(3): 683-690, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32002668

RESUMO

In the search for new antiviral therapies against human immunodeficiency virus type 1 (HIV-1), several cellular targets are being investigated. Ataxia telangiectasia and Rad3-related protein (ATR) has been implicated in HIV-1 replication, namely during retroviral DNA integration. We studied the effect of the ATR inhibitor ETP-46464 on HIV-1 replication in peripheral blood mononuclear cells (PBMCs) and in the persistently HIV-1-infected cell line H61-D. After treatment with ETP-46464, a significant decrease in virus production was observed in both cell systems. Quantification of viral DNA forms in the acutely infected PBMCs suggests that inhibition could take place in the early phase of the viral life cycle before viral DNA integration. Moreover, after treatment of H61-D cells with 3'-azido-3'-deoxythymidine (AZT), which blocks new reverse transcription events, ETP-46464 decreased viral production, suggesting that inhibition of viral replication occurred in the late phase of the life cycle after viral DNA integration. A decrease in virus production after transfection of 293T cells with an HIV-1 infectious molecular clone also suggested that the effect of ETP-46464 is exerted at a post-integration step. We propose that ETP-46464 produces its inhibitory effect on HIV-1 replication by acting in both the early and late phases of the retroviral replication cycle. Thus, ATR could represent a new target for inhibition of HIV-1 replication.


Assuntos
Antivirais/farmacologia , Proteínas Mutadas de Ataxia Telangiectasia/antagonistas & inibidores , HIV-1/efeitos dos fármacos , Oxazinas/farmacologia , Quinolinas/farmacologia , Replicação Viral/efeitos dos fármacos , Linhagem Celular , Humanos
2.
Mutat Res ; 816-818: 111678, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-31557599

RESUMO

The ATR protein kinase is known to protect cells from DNA damage induced during the replicative phase of the cell cycle. Small molecule ATR kinase inhibitors have therefore been developed to improve the effectiveness of DNA damage-based chemotherapy regimens aimed at killing rapidly proliferating tumor cells. However, whether ATR functions in a similar manner in non-replicating cells has not been examined and is important considering the fact that most cells in the body, including cancer stem cells in solid tumors, normally reside in either a quiescent or differentiated non-replicating state. Using cultured human cell lines maintained in a quiescent or slowly growing state in vitro, ATR was found to be activated following treatment with the common anti-cancer drug cisplatin in a manner dependent on the nucleotide excision repair (NER) system. Moreover, treatment with the ATR kinase inhibitors VE-821 and AZD6738 enhanced quiescent cell killing and apoptotic signaling induced by cisplatin. However, ATR kinase inhibition in quiescent cells treated with a low concentration of cisplatin also elevated the level of mutagenesis at the hypoxanthine phosphoribosyltransferase locus and resulted in increased levels of PCNA mono-ubiquitination. These results suggest that the excision gaps generated by NER may require a greater utilization of potentially mutagenic translesion synthesis polymerases in the absence of ATR kinase function. Thus, though ATR kinase inhibitors can aid in the killing of cisplatin-treated quiescent cells, such treatments may also result in a greater reliance on alternative mutagenic DNA polymerases to complete the repair of cisplatin-DNA adducts.


Assuntos
Proteínas Mutadas de Ataxia Telangiectasia/antagonistas & inibidores , Sobrevivência Celular/efeitos dos fármacos , Cisplatino/farmacologia , Mutagênese/efeitos dos fármacos , Inibidores de Proteínas Quinases/farmacologia , Antineoplásicos/farmacologia , Apoptose/efeitos dos fármacos , Ciclo Celular/efeitos dos fármacos , Linhagem Celular , Linhagem Celular Tumoral , Adutos de DNA/farmacologia , Dano ao DNA/efeitos dos fármacos , Reparo do DNA/efeitos dos fármacos , Humanos , Pirazinas/farmacologia , Pirimidinas/farmacologia , Transdução de Sinais/efeitos dos fármacos , Sulfonas/farmacologia , Sulfóxidos/farmacologia
3.
Int J Mol Sci ; 20(15)2019 Jul 29.
Artigo em Inglês | MEDLINE | ID: mdl-31362335

RESUMO

Checkpoint kinase 1 (CHK1) is a central mediator of the DNA damage response (DDR) at the S and G2/M cell cycle checkpoints, and plays a crucial role in preserving genomic integrity. CHK1 overexpression is thought to contribute to cancer aggressiveness, and several selective inhibitors of this kinase are in clinical development for various cancers, including neuroblastoma (NB). Here, we examined the sensitivity of MYCN-amplified NB cell lines to the CHK1 inhibitor PF-477736 and explored mechanisms to increase its efficacy. PF-477736 treatment of two sensitive NB cell lines, SMS-SAN and CHP134, increased the expression of two pro-apoptotic proteins, BAX and PUMA, providing a mechanism for the effect of the CHK1 inhibitor. In contrast, in NB-39-nu and SK-N-BE cell lines, PF-477736 induced DNA double-strand breaks and activated the ataxia telangiectasia mutated serine/threonine kinase (ATM)-p53-p21 axis of the DDR pathway, which rendered the cells relatively insensitive to the antiproliferative effects of the CHK1 inhibitor. Interestingly, combined treatment with PF-477736 and the ATM inhibitor Ku55933 overcame the insensitivity of NB-39-nu and SK-N-BE cells to CHK1 inhibition and induced mitotic cell death. Similarly, co-treatment with PF-477736 and NU7441, a pharmacological inhibitor of DNA-PK, which is also essential for the DDR pathway, rendered the cells sensitive to CHK1 inhibition. Taken together, our results suggest that synthetic lethality between inhibitors of CHK1 and the DDR drives G2/M checkpoint abrogation and could be a novel potential therapeutic strategy for NB.


Assuntos
Antineoplásicos/farmacologia , Apoptose/efeitos dos fármacos , Apoptose/genética , Quinase 1 do Ponto de Checagem/antagonistas & inibidores , Dano ao DNA/efeitos dos fármacos , Inibidores de Proteínas Quinases/farmacologia , Proteínas Mutadas de Ataxia Telangiectasia/antagonistas & inibidores , Proteínas Mutadas de Ataxia Telangiectasia/metabolismo , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Quinase 1 do Ponto de Checagem/genética , Quinase 1 do Ponto de Checagem/metabolismo , Quebras de DNA de Cadeia Dupla , Resistencia a Medicamentos Antineoplásicos , Regulação Neoplásica da Expressão Gênica , Humanos , Neuroblastoma/genética , Neuroblastoma/metabolismo , Ligação Proteica , Transdução de Sinais/efeitos dos fármacos , Ativação Transcricional , Proteína Supressora de Tumor p53/metabolismo
4.
Int J Radiat Oncol Biol Phys ; 105(4): 861-874, 2019 11 15.
Artigo em Inglês | MEDLINE | ID: mdl-31419512

RESUMO

PURPOSE: Telomerase is reactivated in non-small cell lung cancer (NSCLC), and it increases cell resistance to irradiation through protecting damaged telomeres and enhancing DNA damage repair. We investigated the radiosensitizing effect of BIBR1532, a highly selective telomerase inhibitor, and its corresponding mechanism in NSCLC. METHODS AND MATERIALS: Cell proliferation, telomerase activity, and telomere dysfunction-induced foci were measured with CCK-8 assay, real-time fluorescent quantitative polymerase chain reaction, and immunofluorescence. The effect of BIBR1532 on the response of NSCLC cells to radiation was analyzed using clonogenic survival and xenograft tumor assays. Cell death and cell senescence induced by BIBR1532 or ionizing radiation (IR), or both, were detected with western blotting, flow cytometry, and senescence-association ß-galactosidase staining assay. RESULTS: We observed dose-dependent direct cytotoxicity of BIBR1532 at relatively high concentrations in NSCLC cells. Low concentrations of BIBR1532 did not appear toxic to NSCLC cells; however, they substantially increased the therapeutic efficacy of IR in vitro by enhancing IR-induced apoptosis, senescence, and mitotic catastrophe. Moreover, in a mouse xenograft model, BIBR1532 treatment synergized with IR at nontoxic dose levels promoted the antitumor efficacy of IR without toxicity to hematologic and internal organs. Mechanistically, lower concentrations of BIBR1532 effectively inhibited telomerase activity and increased IR-induced telomere dysfunction, resulting in disruption of chromosomal stability and inhibition of the ATM/CHK1 (ataxia-telangiectasia-mutated/Checkpoint kinase 1) pathway, which impaired DNA damage repair. CONCLUSIONS: Our findings demonstrate that disturbances in telomerase function by nontoxic dose levels of BIBR1532 effectively enhance the radiosensitivity of NSCLC cells. This finding provides a rationale for the clinical assessment of BIBR1532 as a radiosensitizer.


Assuntos
Aminobenzoatos/farmacologia , Carcinoma Pulmonar de Células não Pequenas/radioterapia , Neoplasias Pulmonares/radioterapia , Naftalenos/farmacologia , Tolerância a Radiação/efeitos dos fármacos , Radiossensibilizantes/farmacologia , Telomerase/antagonistas & inibidores , Aminobenzoatos/administração & dosagem , Animais , Proteínas Mutadas de Ataxia Telangiectasia/antagonistas & inibidores , Carcinoma Pulmonar de Células não Pequenas/enzimologia , Morte Celular , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Senescência Celular/efeitos dos fármacos , Dano ao DNA/efeitos dos fármacos , Reparo do DNA/efeitos dos fármacos , Relação Dose-Resposta a Droga , Ativação Enzimática/efeitos dos fármacos , Inibidores Enzimáticos/administração & dosagem , Inibidores Enzimáticos/farmacologia , Reativadores Enzimáticos/farmacologia , Feminino , Humanos , Neoplasias Pulmonares/enzimologia , Camundongos , Camundongos Nus , Naftalenos/administração & dosagem , Fosforilação/efeitos dos fármacos , Sincalida , Telomerase/metabolismo , Telômero/efeitos dos fármacos , Homeostase do Telômero/efeitos dos fármacos , Ensaios Antitumorais Modelo de Xenoenxerto
5.
J Ovarian Res ; 12(1): 60, 2019 Jul 05.
Artigo em Inglês | MEDLINE | ID: mdl-31277702

RESUMO

OBJECTIVE: To investigate whether miR-203a-3p can regulate the biological behaviors of ovarian cancer cells by targeting ATM to affect the Akt/GSK-3ß/Snail signaling pathway. METHODS: The expression levels of miR-203a-3p and ATM were detected by qRT-PCR, immunohistochemical staining and Western blotting in ovarian cancer tissues and adjacent normal tissues obtained from 152 subjects. A dual-luciferase reporter gene assay was performed to verify the relationship between miR-203a-3p and ATM. Human ovarian cancer cell lines (A2780 and SKOV3) were used to generate the Blank, miR-NC, miR-203a-3p mimic, Control siRNA, ATM siRNA, and miR-203a-3p inhibitor + ATM siRNA groups. The biological behaviors of ovarian cancer cells were evaluated by CCK-8, wound healing, and Transwell invasion assays, annexin V-FITC/PI staining and flow cytometry. The levels of Akt/GSK-3ß/Snail pathway-related proteins were assessed by Western blotting. RESULTS: Ovarian cancer tissues showed lower miR-203a-3p levels and higher ATM levels than adjacent normal tissues, both of which were associated with the FIGO stage, grade and prognosis of ovarian cancer. As confirmed by a dual-luciferase reporter gene assay, miR-203a-3p could target ATM. Furthermore, the miR-203a-3p mimic had multiple effects, including the inhibition of the proliferation, invasion and migration of A2780 and SKOV3 cells, the promotion of cell apoptosis, the arrest of the cell cycle at the G1 phase, and the blockage of the Akt/GSK-3ß/Snail signaling pathway. ATM siRNA had similar effects on the biological behaviors of ovarian cancer cells, and these effects could be reversed by a miR-203a-3p inhibitor. CONCLUSION: miR-203a-3p was capable of hindering proliferation, migration, and invasion and facilitating the apoptosis of ovarian cancer cells through its modulation of the Akt/GSK-3ß/Snail signaling pathway by targeting ATM, and therefore it could serve as a potential therapeutic option for ovarian cancer.


Assuntos
Proteínas Mutadas de Ataxia Telangiectasia/genética , MicroRNAs/metabolismo , Neoplasias Ovarianas/fisiopatologia , Proteínas Proto-Oncogênicas c-akt/metabolismo , Transdução de Sinais , Adulto , Idoso , Proteínas Mutadas de Ataxia Telangiectasia/antagonistas & inibidores , Proteínas Mutadas de Ataxia Telangiectasia/metabolismo , Linhagem Celular Tumoral , Movimento Celular/genética , Proliferação de Células/genética , Feminino , Regulação Neoplásica da Expressão Gênica , Glicogênio Sintase Quinase 3 beta/genética , Glicogênio Sintase Quinase 3 beta/metabolismo , Humanos , MicroRNAs/antagonistas & inibidores , MicroRNAs/genética , Pessoa de Meia-Idade , Invasividade Neoplásica/genética , Neoplasias Ovarianas/genética , Neoplasias Ovarianas/metabolismo , Fosforilação , Prognóstico , Proteínas Proto-Oncogênicas c-akt/genética , RNA Interferente Pequeno , Fatores de Transcrição da Família Snail/genética
6.
Int J Radiat Oncol Biol Phys ; 105(2): 410-422, 2019 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-31255687

RESUMO

PURPOSE: Fibroblast growth factor receptor 2 (FGFR2) has been previously reported to be overexpressed in several types of cancer, whereas the expression in normal tissue is considered to be moderate to low. Thus, FGFR2 is regarded as an attractive tumor antigen for targeted alpha therapy. This study reports the evaluation of an FGFR2-targeted thorium-227 conjugate (FGFR2-TTC, BAY 2304058) comprising an anti-FGFR2 antibody, a chelator moiety covalently conjugated to the antibody, and the alpha particle-emitting radionuclide thorium-227. FGFR2-TTC was assessed as a monotherapy and in combination with the DNA damage response inhibitor ATRi BAY 1895344. METHODS AND MATERIALS: The in vitro cytotoxicity and mechanism of action were evaluated by determining cell viability, the DNA damage response marker γH2A.X, and cell cycle analyses. The in vivo efficacy was determined using human tumor xenograft models in nude mice. RESULTS: In vitro mechanistic assays demonstrated upregulation of γH2A.X and induction of cell cycle arrest in several FGFR2-expressing cancer cell lines after treatment with FGFR2-TTC. In vivo, FGFR2-TTC significantly inhibited tumor growth at a dose of 500 kBq/kg in the xenograft models NCI-H716, SNU-16, and MFM-223. By combining FGFR2-TTC with the ATR inhibitor BAY 1895344, an increased potency was observed in vitro, as were elevated levels of γH2A.X and inhibition of FGFR2-TTC-mediated cell cycle arrest. In the MFM-223 tumor xenograft model, combination of the ATRi BAY 1895344 with FGFR2-TTC resulted in significant tumor growth inhibition at doses at which the single agents had no effect. CONCLUSIONS: The data provide a mechanism-based rationale for combining the FGFR2-TTC with the ATRi BAY 1895344 as a new therapeutic approach for treatment of FGFR2-positive tumors from different cancer indications.


Assuntos
Anticorpos Monoclonais Humanizados/uso terapêutico , Proteínas Mutadas de Ataxia Telangiectasia/antagonistas & inibidores , Neoplasias da Mama/radioterapia , Inibidores de Proteínas Quinases/uso terapêutico , Radioimunoterapia/métodos , Receptor Tipo 2 de Fator de Crescimento de Fibroblastos/uso terapêutico , Tório/uso terapêutico , Animais , Neoplasias da Mama/metabolismo , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Quelantes/uso terapêutico , Dano ao DNA , Combinação de Medicamentos , Sinergismo Farmacológico , Pontos de Checagem da Fase G2 do Ciclo Celular/efeitos da radiação , Histonas/metabolismo , Humanos , Imunoconjugados/química , Imunoconjugados/farmacocinética , Imunoconjugados/uso terapêutico , Camundongos , Camundongos Nus , Terapia de Alvo Molecular/métodos , Receptor Tipo 2 de Fator de Crescimento de Fibroblastos/antagonistas & inibidores , Receptor Tipo 2 de Fator de Crescimento de Fibroblastos/metabolismo , Tório/farmacocinética , Compostos de Tório/uso terapêutico , Regulação para Cima , Ensaios Antitumorais Modelo de Xenoenxerto
7.
Crit Rev Oncol Hematol ; 138: 214-222, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31092378

RESUMO

The Ataxia Telangiectasia Mutated (ATM)-mediated DNA damage response (DDR) is a major mechanism of resistance of glioblastoma (GB) - initiating cells (GICs) to radiotherapy. The closely related Ataxia Telangiectasia and Rad3-related protein (ATR) is also involved in tumor resistance to radio- and chemotherapy. It has been shown that pharmacological inhibition of ATM protein may overcome the DDR-mediated resistance in GICs and significantly radiosensitize GIC-driven GB. Albeit not essential for life as shown by the decade-long lifespan of AT patients, the ATM protein may be involved in a number of important functions other than the response to DNA damage. We discuss our current knowledge about the toxicity of pharmacologic inhibition of ATM and ATR proteins.


Assuntos
Proteínas Mutadas de Ataxia Telangiectasia/antagonistas & inibidores , Neoplasias Encefálicas/patologia , Glioblastoma/patologia , Radiossensibilizantes/farmacologia , Adulto , Animais , Dano ao DNA/efeitos dos fármacos , Humanos , Células-Tronco Neoplásicas/efeitos dos fármacos , Tolerância a Radiação/efeitos dos fármacos
8.
J Exp Clin Cancer Res ; 38(1): 149, 2019 Apr 08.
Artigo em Inglês | MEDLINE | ID: mdl-30961670

RESUMO

BACKGROUND: The cisplatin-resistance is still a main course for chemotherapy failure of lung cancer patients. Cisplatin-resistant cancer cells own higher malignance and exhibited increased metastatic ability, but the mechanism is not clear. In this study, we investigated the effects of Ataxia Telangiectasia Mutated (ATM) on lung cancer metastasis. MATERIALS AND METHODS: Cisplatin-resistant A549CisR and H157CisR cell line were generated by long-term treating parental A549 and H157 cells (A549P and H157P) with cisplatin. Cell growth, cell migration and cell invasion were determined. Gene expressions were determined by Western Blot and qPCR. Tumor metastasis was investigated using a xenograft mouse model. RESULTS: The IC50 of the cisplatin-resistant cells (A549CisR and H157CisR cells) to cisplatin was 6-8 higher than parental cells. The A549CisR and H157CisR cells expressed lower level of E-cadherin and higher levels of N-cadherin, Vimentin and Snail compared to the parental A549P and H157P cells, and exhibited stronger capabilities of metastatic potential compared to the parental cells. The ATM expression was upregulated in A549CisR and H157CisR cells and cisplatin treatment also upregulated expression of ATM in parental cells, The inhibition of ATM by using specific ATM inhibitor CP466722 or knock-down ATM by siRNA suppressed Epithelial-to-Mesenchymal transition (EMT) and metastatic potential of A549CisR and H157CisR cells. These data suggest that ATM mediates the cisplatin-resistance in lung cancer cells. Expressions of JAK1,2,、 STAT3 、PD-L1 and ATM were increased in A549CisR and H157CisR cells and could by induced by cisplatin in parental lung cancer cells. Interestedly, ATM upregulated PD-L1 expression via JAK1,2/STAT3 pathway and inhibition of ATM decreased JAK/STAT3 signaling and decreased PD-L1 expression. The treatment of PD-L1 neutralizing Ab reduced EMT and cell invasion. Inhibition of JAK1,2/STAT3 signaling by specific inhibitors suppressed ATM-induced PD-L1 expression, EMT and cell invasion. Importantly, inhibition of ATM suppressed EMT and tumor metastasis in cisplatin-resistant lung cancer cells in an orthotopic xenograft mouse model. CONCLUSIONS: Our results show that ATM regulates PD-L1 expression through activation of JAK/STAT3 signaling in cisplatin-resistant cells. Overexpression of ATM contributes to cisplatin-resistance in lung cancer cells. Inhibition of ATM reversed EMT and inhibited cell invasion and tumor metastasis. Thus, ATM may be a potential target for the treatment of cisplatin-resistant lung cancer.


Assuntos
Proteínas Mutadas de Ataxia Telangiectasia/antagonistas & inibidores , Ataxia Telangiectasia/genética , Transição Epitelial-Mesenquimal/efeitos dos fármacos , Neoplasias Pulmonares/genética , Fator de Transcrição STAT3/metabolismo , Animais , Ataxia Telangiectasia/patologia , Humanos , Neoplasias Pulmonares/patologia , Camundongos , Metástase Neoplásica
9.
Biochem Pharmacol ; 164: 273-282, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-31014753

RESUMO

Resistance to standard induction therapy and relapse remain the primary challenges for improving therapeutic effects in acute myeloid leukemia (AML); thus, novel therapeutic strategies are urgently required. Ataxia telangiectasia and Rad3-related protein (ATR) is a key regulator of different types of DNA damage, which is crucial for the maintenance of genomic integrity. The ATR-selective inhibitor VE-822 has proper solubility, potency, and pharmacokinetic properties. In this study, we investigated the anti-leukemic effects of VE-822 alone or combined with Wee1-selective inhibitor AZD1775 in AML cells. Our results showed that VE-822 inhibited AML cell proliferation and induced apoptosis in a dose-dependent manner. AZD1775 significantly promoted VE-822-induced inhibition of AML cell proliferation and led to a decreased number of cells in the G2/M phase. VE-822 and AZD1775 decreased the protein levels of ribonucleotide reductase M1 (RRM1) and M2 (RRM2) subunits, key enzymes in the synthesis of deoxyribonucleoside triphosphate, which increased DNA replication stress. VE-822 combined with AZD1775 synergistically induced AML cell apoptosis and led to replication stress and DNA damage in AML cell lines. Our study demonstrated that AZD1775 synergistically promotes VE-822-induced anti-leukemic activity in AML cell lines and provides support for clinical research on VE-822 in combination with AZD1775 for the treatment of AML patients.


Assuntos
Apoptose/fisiologia , Proteínas Mutadas de Ataxia Telangiectasia/metabolismo , Proteínas de Ciclo Celular/metabolismo , Dano ao DNA/fisiologia , Isoxazóis/farmacologia , Leucemia Mieloide Aguda/metabolismo , Proteínas Tirosina Quinases/metabolismo , Pirazinas/farmacologia , Apoptose/efeitos dos fármacos , Proteínas Mutadas de Ataxia Telangiectasia/antagonistas & inibidores , Proteínas de Ciclo Celular/antagonistas & inibidores , Dano ao DNA/efeitos dos fármacos , Relação Dose-Resposta a Droga , Humanos , Leucemia Mieloide Aguda/patologia , Proteínas Tirosina Quinases/antagonistas & inibidores , Células U937
10.
Leukemia ; 33(10): 2365-2378, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-30940905

RESUMO

Bone marrow (BM) niche responds to chemotherapy-induced cytokines secreted from acute lymphoblastic leukemia (ALL) cells and protects the residual cells from chemotherapeutics in vivo. However, the underlying molecular mechanisms for the induction of cytokines by chemotherapy remain unknown. Here, we found that chemotherapeutic drugs (e.g., Ara-C, DNR, 6-MP) induced the expression of niche-protecting cytokines (GDF15, CCL3 and CCL4) in both ALL cell lines and primary cells in vitro. The ATM and NF-κB pathways were activated after chemotherapy treatment, and the pharmacological or genetic inhibition of these pathways significantly reversed the cytokine upregulation. Besides, chemotherapy-induced NF-κB activation was dependent on ATM-TRAF6 signaling, and NF-κB transcription factor p65 directly regulated the cytokines expression. Furthermore, we found that both pharmacological and genetic perturbation of ATM and p65 significantly decreased the residual ALL cells after Ara-C treatment in ALL xenograft mouse models. Together, these results demonstrated that ATM-dependent NF-κB activation mediated the cytokines induction by chemotherapy and ALL resistance to chemotherapeutics. Inhibition of ATM-dependent NF-κB pathway can sensitize ALL to chemotherapeutics, providing a new strategy to eradicate residual chemo-resistant ALL cells.


Assuntos
Proteínas Mutadas de Ataxia Telangiectasia/antagonistas & inibidores , NF-kappa B/antagonistas & inibidores , Leucemia-Linfoma Linfoblástico de Células Precursoras/tratamento farmacológico , Transdução de Sinais/efeitos dos fármacos , Animais , Antineoplásicos , Linhagem Celular Tumoral , Criança , Citocinas/metabolismo , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Feminino , Regulação Leucêmica da Expressão Gênica/efeitos dos fármacos , Humanos , Camundongos , Camundongos Endogâmicos NOD , Camundongos SCID , Leucemia-Linfoma Linfoblástico de Células Precursoras/metabolismo , Fator 6 Associado a Receptor de TNF/metabolismo
11.
Nat Commun ; 10(1): 1686, 2019 04 11.
Artigo em Inglês | MEDLINE | ID: mdl-30975996

RESUMO

Cohesin is a multiprotein ring that is responsible for cohesion of sister chromatids and formation of DNA loops to regulate gene expression. Genomic analyses have identified that the cohesin subunit STAG2 is frequently inactivated by mutations in cancer. However, the reason STAG2 mutations are selected during tumorigenesis and strategies for therapeutically targeting mutant cancer cells are largely unknown. Here we show that STAG2 is essential for DNA replication fork progression, whereby STAG2 inactivation in non-transformed cells leads to replication fork stalling and collapse with disruption of interaction between the cohesin ring and the replication machinery as well as failure to establish SMC3 acetylation. As a consequence, STAG2 mutation confers synthetic lethality with DNA double-strand break repair genes and increased sensitivity to select cytotoxic chemotherapeutic agents and PARP or ATR inhibitors. These studies identify a critical role for STAG2 in replication fork procession and elucidate a potential therapeutic strategy for cohesin-mutant cancers.


Assuntos
Antígenos Nucleares/metabolismo , Antineoplásicos/farmacologia , Proteínas de Ciclo Celular/genética , Proteínas Cromossômicas não Histona/genética , Neoplasias/genética , Mutações Sintéticas Letais , Antígenos Nucleares/genética , Antineoplásicos/uso terapêutico , Proteínas Mutadas de Ataxia Telangiectasia/antagonistas & inibidores , Proteínas Mutadas de Ataxia Telangiectasia/metabolismo , Carcinogênese/genética , Linhagem Celular Tumoral , Cromátides/metabolismo , Quebras de DNA de Cadeia Dupla , Replicação do DNA , Ensaios de Seleção de Medicamentos Antitumorais , Técnicas de Inativação de Genes , Humanos , Mutagênese , Neoplasias/tratamento farmacológico , Inibidores de Poli(ADP-Ribose) Polimerases/farmacologia , Inibidores de Poli(ADP-Ribose) Polimerases/uso terapêutico , Poli(ADP-Ribose) Polimerases/metabolismo , RNA Interferente Pequeno/metabolismo , Reparo de DNA por Recombinação
12.
Cancer Lett ; 451: 23-33, 2019 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-30872077

RESUMO

Targeting cell cycle has become one of the major challenges in cancer therapy, being Palbociclib, a CDK4/6 inhibitor, an excellent example. Recently, it has been reported that Palbociclib could be a novel radiosensitizer agent. In an attempt to clarify the molecular basis of this effect we have used cell lines from colorectal (HT29, HCT116) lung (A549, H1299) and breast cancer (MCF-7). Our results indicate that the presence of a p53 wild type is strictly required for Palbociclib to exert its radiosensitizing effect, independently of the inhibitory effect exerted on CDK4/6. In fact, abrogation of p53 in cells with functional p53 blocks the radiosensitizing effect of Palbociclib. Moreover, no radiosensitizing effect is observed in cells with non-functional p53, but restoration of p53 function promotes radiosensitivity associated to Palbociclib. Furthermore, the presence of Palbociclib blocks the transcriptional activity of p53 in an ATM-dependent-fashion after ionizing radiation exposure, as the blockage of p21/WAF1 expression demonstrates. These observations are a proof of concept for a more selective therapy, based on the combination of CDK4/6 inhibition and radiotherapy, which would only benefit to those patients with a functional p53 pathway.


Assuntos
Piperazinas/farmacologia , Piridinas/farmacologia , Radiossensibilizantes/farmacologia , Proteína Supressora de Tumor p53/metabolismo , Proteínas Mutadas de Ataxia Telangiectasia/antagonistas & inibidores , Proteínas Mutadas de Ataxia Telangiectasia/metabolismo , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Quinase 4 Dependente de Ciclina/antagonistas & inibidores , Quinase 6 Dependente de Ciclina/antagonistas & inibidores , Humanos , Transdução de Sinais/efeitos dos fármacos
13.
Mol Cancer Ther ; 18(4): 762-770, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30872379

RESUMO

Small cell lung cancer (SCLC) is generally regarded as very difficult to treat, mostly due to the development of metastases early in the disease and a quick relapse with resistant disease. SCLC patients initially show a good response to treatment with the DNA damaging agents cisplatin and etoposide. This is, however, quickly followed by the development of resistant disease, which urges the development of novel therapies for this type of cancer. In this study, we set out to compile a comprehensive overview of the vulnerabilities of SCLC. A functional genome-wide screen where all individual genes were knocked out was performed to identify novel vulnerabilities of SCLC. By analysis of the knockouts that were lethal to these cancer cells, we identified several processes to be synthetic vulnerabilities in SCLC. We were able to validate the vulnerability to inhibition of the replication stress response machinery by use of Chk1 and ATR inhibitors. Strikingly, SCLC cells were more sensitive to these inhibitors than nontransformed cells. In addition, these inhibitors work synergistically with either etoposide and cisplatin, where the interaction is largest with the latter. ATR inhibition by VE-822 treatment in combination with cisplatin also outperforms the combination of cisplatin with etoposide in vivo Altogether, our study uncovered a critical dependence of SCLC on the replication stress response and urges the validation of ATR inhibitors in combination with cisplatin in a clinical setting.


Assuntos
Antineoplásicos/uso terapêutico , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Cisplatino/uso terapêutico , Isoxazóis/uso terapêutico , Neoplasias Pulmonares/tratamento farmacológico , Inibidores de Proteínas Quinases/uso terapêutico , Pirazinas/uso terapêutico , Carcinoma de Pequenas Células do Pulmão/tratamento farmacológico , Células A549 , Animais , Antineoplásicos/administração & dosagem , Protocolos de Quimioterapia Combinada Antineoplásica/administração & dosagem , Proteínas Mutadas de Ataxia Telangiectasia/antagonistas & inibidores , Proteína 9 Associada à CRISPR/genética , Sobrevivência Celular/efeitos dos fármacos , Quinase 1 do Ponto de Checagem/antagonistas & inibidores , Cisplatino/administração & dosagem , Dano ao DNA/efeitos dos fármacos , Sinergismo Farmacológico , Etoposídeo/administração & dosagem , Etoposídeo/uso terapêutico , Humanos , Isoxazóis/administração & dosagem , Isoxazóis/farmacologia , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Inibidores de Proteínas Quinases/administração & dosagem , Inibidores de Proteínas Quinases/farmacologia , Pirazinas/administração & dosagem , Pirazinas/farmacologia , Carga Tumoral/efeitos dos fármacos , Ensaios Antitumorais Modelo de Xenoenxerto
14.
Breast Cancer Res Treat ; 175(2): 339-351, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30826934

RESUMO

PURPOSE: Triple-negative breast cancer (TNBC) lacks the receptor targets estrogen receptor, progesterone receptor, and human epidermal growth factor receptor 2, and thus, it does not respond to receptor-targeted treatments. TNBC has higher recurrence, metastasis, and mortality rates than other subtypes of breast cancer. Mounting data suggest that the MAPK (also known as RAS-RAF-MEK-ERK) pathway is an important therapeutic target in TNBC. METHODS: To evaluate anti-tumor and anti-metastasis efficacy of E6201, we used cell proliferation assay, soft agar assay, cell cycle assay, Annexin V staining assay, immunoblotting analysis, immunohistochemistry, migration assay, invasion assay, mammary fat pad xenograft, and experimental and spontaneous metastasis xenograft models. We also evaluated the anti-tumor efficacy of E6201 plus CDK4/6 inhibitor, mTOR inhibitor, or ATR inhibitor. RESULTS: E6201 inhibited TNBC cell colony formation, migration, and invasion in a dose-dependent manner. E6201 induced G1 cell cycle arrest and apoptosis. E6201 inhibited TNBC xenograft growth and inhibited TNBC lung metastasis and improved mouse survival in experimental metastasis and spontaneous metastasis assays. Immunohistochemical staining demonstrated that E6201 decreased the metastatic burden in the lung and decreased phosphorylated ERK expression in a dose-dependent manner. Combination of E6201 with CDK4/6 inhibitor or mTOR inhibitor enhanced E6201's in vitro anti-tumor efficacy. CONCLUSION: These results indicate that E6201 exhibits anti-tumor efficacy against TNBC in vitro and anti-metastasis efficacy against TNBC in vivo. These results provide a rationale for further clinical development of E6201 as a MAPK-pathway-targeted therapy for TNBC.


Assuntos
Proliferação de Células/efeitos dos fármacos , Lactonas/farmacologia , MAP Quinase Quinase 1/genética , Neoplasias de Mama Triplo Negativas/tratamento farmacológico , Animais , Apoptose/efeitos dos fármacos , Proteínas Mutadas de Ataxia Telangiectasia/antagonistas & inibidores , Proteínas Mutadas de Ataxia Telangiectasia/genética , Pontos de Checagem do Ciclo Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Quinase 4 Dependente de Ciclina/antagonistas & inibidores , Quinase 4 Dependente de Ciclina/genética , Feminino , Xenoenxertos , Humanos , MAP Quinase Quinase 1/antagonistas & inibidores , Camundongos , Metástase Neoplásica , Inibidores de Proteínas Quinases/farmacologia , Serina-Treonina Quinases TOR/antagonistas & inibidores , Serina-Treonina Quinases TOR/genética , Neoplasias de Mama Triplo Negativas/genética , Neoplasias de Mama Triplo Negativas/patologia
15.
EBioMedicine ; 41: 370-383, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30799198

RESUMO

BACKGROUND: Cancer-associated fibroblasts (CAFs) are the predominant residents in the breast tumor microenvironment. In our work, we found activation of DNA damage-independent ATM (oxidized ATM), enhanced glycolysis and aberrant metabolism-associated gene expressions in breast CAFs. Nevertheless, whether and how oxidized ATM regulates the glycolytic activity of CAFs keep in unveil. Recently, a reverse Warburg effect was observed in tumor tissues, in which host cells (such as CAFs, PSCs) in the tumor microenvironment have been found to "fuel" the cancer cells via metabolites transfer. However, the molecular mechanisms of the metabolites from stromal cells playing a role to the progression of cancer cells remain to be determined. METHODS: Oxidized ATM activation in stromal CAFs was assessed by western blotting and immunofluorescence. The increased glycolytic ability of CAFs was validated by measurements of OCR and ECAR and detections of glucose consumption and lactate production. Kinase assay and western blotting were performed to confirm the phosphorylation of GLUT1. The membrane location of phosphorylated GLUT1 was determined by biotin pull-down assay and immunofluorescence staining. The regulation of PKM2 through oxidized ATM was evaluated by western blots. In addition, the impact of lactate derived from hypoxic CAFs on cancer cell invasion was investigated both in vitro (transwell assays, western blots) and in vivo (orthotopic xenografts). FINDINGS: Hypoxia-induced oxidized ATM promotes glycolytic activity of CAFs by phosphorylating GLUT1 at S490 and increasing PKM2 expression. Moreover, lactate derived from hypoxic CAFs, acting as a metabolic coupling between CAFs and breast cancer cells, promotes breast cancer cell invasion by activating the TGFß1/p38 MAPK/MMP2/9 signaling axis and fueling the mitochondrial activity in cancer cells. INTERPRETATION: Our work shows that oxidized ATM-mediated glycolysis enhancement in hypoxic stromal fibroblasts plays an essential role in cancer cell invasion and metastasis and may implicate oxidized ATM as a target for breast tumor treatment. FUND: This research was supported by National Natural Science Foundation of China.


Assuntos
Proteínas Mutadas de Ataxia Telangiectasia/metabolismo , Ácido Láctico/metabolismo , Animais , Proteínas Mutadas de Ataxia Telangiectasia/antagonistas & inibidores , Proteínas Mutadas de Ataxia Telangiectasia/genética , Neoplasias da Mama/patologia , Fibroblastos Associados a Câncer/citologia , Fibroblastos Associados a Câncer/metabolismo , Proteínas de Transporte/antagonistas & inibidores , Proteínas de Transporte/genética , Proteínas de Transporte/metabolismo , Hipóxia Celular , Movimento Celular , Células Cultivadas , Feminino , Glucose/metabolismo , Transportador de Glucose Tipo 1/antagonistas & inibidores , Transportador de Glucose Tipo 1/genética , Transportador de Glucose Tipo 1/metabolismo , Glicólise , Humanos , Proteínas de Membrana/antagonistas & inibidores , Proteínas de Membrana/genética , Proteínas de Membrana/metabolismo , Camundongos , Mitocôndrias/metabolismo , Fosforilação Oxidativa , Interferência de RNA , RNA Interferente Pequeno/metabolismo , Transdução de Sinais , Hormônios Tireóideos/genética , Hormônios Tireóideos/metabolismo
16.
Mol Cells ; 42(3): 210-217, 2019 Mar 31.
Artigo em Inglês | MEDLINE | ID: mdl-30726661

RESUMO

The maintenance of mitochondrial function is closely linked to the control of senescence. In our previous study, we uncovered a novel mechanism in which senescence amelioration in normal aging cells is mediated by the recovered mitochondrial function upon Ataxia telangiectasia mutated (ATM) inhibition. However, it remains elusive whether this mechanism is also applicable to senescence amelioration in accelerated aging cells. In this study, we examined the role of ATM inhibition on mitochondrial function in Hutchinson-Gilford progeria syndrome (HGPS) and Werner syndrome (WS) cells. We found that ATM inhibition induced mitochondrial functional recovery accompanied by metabolic reprogramming, which has been known to be a prerequisite for senescence alleviation in normal aging cells. Indeed, the induced mitochondrial metabolic reprogramming was coupled with senescence amelioration in accelerated aging cells. Furthermore, the therapeutic effect via ATM inhibition was observed in HGPS as evidenced by reduced progerin accumulation with concomitant decrease of abnormal nuclear morphology. Taken together, our data indicate that the mitochondrial functional recovery by ATM inhibition might represent a promising strategy to ameliorate the accelerated aging phenotypes and to treat age-related disease.


Assuntos
Envelhecimento/metabolismo , Proteínas Mutadas de Ataxia Telangiectasia/antagonistas & inibidores , Senescência Celular , Modelos Biológicos , Proteínas Mutadas de Ataxia Telangiectasia/metabolismo , Forma do Núcleo Celular , Quebras de DNA de Cadeia Dupla , Fibroblastos/patologia , Humanos , Lamina Tipo A/metabolismo , Mitocôndrias/metabolismo , Progéria/patologia
17.
J Virol ; 93(9)2019 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-30787154

RESUMO

Oncogenic virus replication often leads to genomic instability, causing DNA damage and inducing the DNA damage response (DDR) pathway. The DDR pathway is a cellular pathway that senses DNA damage and regulates the cell cycle to maintain genomic stability. Therefore, the DDR pathway is critical for the viral lifecycle and tumorigenesis. Marek's disease virus (MDV), an alphaherpesvirus that causes lymphoma in chickens, has been shown to induce DNA damage in infected cells. However, the interaction between MDV and the host DDR is unclear. In this study, we observed that MDV infection causes DNA strand breakage in chicken fibroblast (CEF) cells along with an increase in the DNA damage markers p53 and p21. Interestingly, we showed that phosphorylation of STAT3 was increased during MDV infection, concomitantly with a decrease of Chk1 phosphorylation. In addition, we found that MDV infection was enhanced by VE-821, an ATR-specific inhibitor, but attenuated by hydroxyurea, an ATR activator. Moreover, inhibition of STAT3 phosphorylation by Stattic eliminates the ability of MDV to inhibit Chk1 phosphorylation. Finally, we showed that MDV replication was decreased by Stattic treatment. Taken together, these results suggest that MDV disables the ATR-Chk1 pathway through STAT3 activation to benefit its replication.IMPORTANCE MDV is used as a biomedical model to study virus-induced lymphoma due to the similar genomic structures and physiological characteristics of MDV and human herpesviruses. Upon infection, MDV induces DNA damage, which may activate the DDR pathway. The DDR pathway has a dual impact on viruses because it manipulates repair and recombination factors to facilitate viral replication and also initiates antiviral action by regulating other signaling pathways. Many DNA viruses evolve to manipulate the DDR pathway to promote virus replication. In this study, we identified a mechanism used by MDV to inhibit ATR-Chk1 pathways. ATR is a cellular kinase that responds to broken single-stranded DNA, which has been less studied in MDV infection. Our results suggest that MDV infection activates STAT3 to disable the ATR-Chk1 pathway, which is conducive to viral replication. This finding provides new insight into the role of STAT3 in interrupting the ATR-Chk1 pathway during MDV replication.


Assuntos
Proteínas Mutadas de Ataxia Telangiectasia/metabolismo , Proteínas Aviárias/metabolismo , Quinase 1 do Ponto de Checagem/metabolismo , Mardivirus/fisiologia , Doença de Marek/metabolismo , Fator de Transcrição STAT3/metabolismo , Replicação Viral/fisiologia , Animais , Proteínas Mutadas de Ataxia Telangiectasia/antagonistas & inibidores , Proteínas Mutadas de Ataxia Telangiectasia/genética , Proteínas Aviárias/genética , Linhagem Celular , Quinase 1 do Ponto de Checagem/genética , Galinhas , Inibidor de Quinase Dependente de Ciclina p21/genética , Inibidor de Quinase Dependente de Ciclina p21/metabolismo , Dano ao DNA , Doença de Marek/genética , Doença de Marek/patologia , Pirazinas/farmacologia , Fator de Transcrição STAT3/genética , Sulfonas/farmacologia , Proteína Supressora de Tumor p53/genética , Proteína Supressora de Tumor p53/metabolismo , Replicação Viral/efeitos dos fármacos
18.
Nucleic Acids Res ; 47(6): 2739-2756, 2019 04 08.
Artigo em Inglês | MEDLINE | ID: mdl-30759257

RESUMO

G-quadruplex ligands exert their antiproliferative effects through telomere-dependent and telomere-independent mechanisms, but the inter-relationships among autophagy, cell growth arrest and cell death induced by these ligands remain largely unexplored. Here, we demonstrate that the G-quadruplex ligand 20A causes growth arrest of cancer cells in culture and in a HeLa cell xenografted mouse model. This response is associated with the induction of senescence and apoptosis. Transcriptomic analysis of 20A treated cells reveals a significant functional enrichment of biological pathways related to growth arrest, DNA damage response and the lysosomal pathway. 20A elicits global DNA damage but not telomeric damage and activates the ATM and autophagy pathways. Loss of ATM following 20A treatment inhibits both autophagy and senescence and sensitizes cells to death. Moreover, disruption of autophagy by deletion of two essential autophagy genes ATG5 and ATG7 leads to failure of CHK1 activation by 20A and subsequently increased cell death. Our results, therefore, identify the activation of ATM by 20A as a critical player in the balance between senescence and apoptosis and autophagy as one of the key mediators of such regulation. Thus, targeting the ATM/autophagy pathway might be a promising strategy to achieve the maximal anticancer effect of this compound.


Assuntos
Apoptose/efeitos dos fármacos , Proteínas Mutadas de Ataxia Telangiectasia , Autofagia/efeitos dos fármacos , Senescência Celular/efeitos dos fármacos , Quadruplex G , Neoplasias/patologia , Células A549 , Animais , Apoptose/genética , Proteínas Mutadas de Ataxia Telangiectasia/antagonistas & inibidores , Proteínas Mutadas de Ataxia Telangiectasia/metabolismo , Autofagia/genética , Linhagem Celular Tumoral , Senescência Celular/genética , Dano ao DNA/efeitos dos fármacos , Células HeLa , Humanos , Ligantes , Masculino , Camundongos , Camundongos Endogâmicos NOD , Camundongos Knockout , Camundongos SCID , Neoplasias/genética , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/genética , Ensaios Antitumorais Modelo de Xenoenxerto
19.
BMB Rep ; 52(3): 208-213, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30638177

RESUMO

Chemoresistance is the primary obstacle in the treatment of locally advanced and metastatic nasopharyngeal carcinoma (NPC). Recent evidence suggests that the transcription factor forkhead box M1 (FoxM1) is involved in chemoresistance. Our group previously confirmed that FoxM1 is overexpressed in NPC. In this study, we investigated the role of FoxM1 in cisplatin resistance of the cell lines 5-8F and HONE-1 and explored its possible mechanism. Our results showed that FoxM1 and NBS1 were both overexpressed in NPC tissues based on data from the GSE cohort (GSE12452). Then, we measured FoxM1 levels in NPC cells and found FoxM1 was overexpressed in NPC cell lines and could be stimulated by cisplatin. MTT and clonogenic assays, flow cytometry, γH2AX immunofluorescence, qRT-PCR, and western blotting revealed that downregulation of FoxM1 sensitized NPC cells to cisplatin and reduced the repair of cisplatin-induced DNA double-strand breaks via inhibition of the MRN (MRE11-RAD50-NBS1)-ATM axis, which might be related to the ability of FoxM1 to regulate NBS1. Subsequently, we demonstrated that enhanced sensitivity of FoxM1 knockdown cells could be reduced by overexpression of NBS1. Taken together, our data demonstrate that downregulation of FoxM1 could improve the sensitivity of NPC cells to cisplatin through inhibition of MRN-ATM-mediated DNA repair, which could be related to FoxM1-dependent regulation of NBS1. [BMB Reports 2019; 52(3): 208-213].


Assuntos
Proteínas Mutadas de Ataxia Telangiectasia/antagonistas & inibidores , Cisplatino/farmacologia , Reparo do DNA , Proteína Forkhead Box M1/genética , Carcinoma Nasofaríngeo/tratamento farmacológico , Carcinoma Nasofaríngeo/metabolismo , Antineoplásicos/farmacologia , Proteínas Mutadas de Ataxia Telangiectasia/biossíntese , Proteínas Mutadas de Ataxia Telangiectasia/genética , Proteínas de Ciclo Celular/antagonistas & inibidores , Proteínas de Ciclo Celular/biossíntese , Proteínas de Ciclo Celular/genética , Proteínas de Ciclo Celular/metabolismo , Linhagem Celular Tumoral , Enzimas Reparadoras do DNA/antagonistas & inibidores , Enzimas Reparadoras do DNA/biossíntese , Enzimas Reparadoras do DNA/genética , Proteínas de Ligação a DNA/antagonistas & inibidores , Proteínas de Ligação a DNA/biossíntese , Proteínas de Ligação a DNA/genética , Regulação para Baixo , Resistencia a Medicamentos Antineoplásicos , Proteína Forkhead Box M1/biossíntese , Proteína Forkhead Box M1/metabolismo , Humanos , Proteína Homóloga a MRE11/antagonistas & inibidores , Proteína Homóloga a MRE11/biossíntese , Proteína Homóloga a MRE11/genética , Carcinoma Nasofaríngeo/genética , Proteínas Nucleares/antagonistas & inibidores , Proteínas Nucleares/biossíntese , Proteínas Nucleares/genética , Proteínas Nucleares/metabolismo
20.
J Clin Invest ; 129(3): 1329-1344, 2019 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-30645202

RESUMO

We used the cancer-intrinsic property of oncogene-induced DNA damage as the base for a conditional synthetic lethality approach. To target mechanisms important for cancer cell adaptation to genotoxic stress and thereby to achieve cancer cell-specific killing, we combined inhibition of the kinases ATR and Wee1. Wee1 regulates cell cycle progression, whereas ATR is an apical kinase in the DNA-damage response. In an orthotopic breast cancer model, tumor-selective synthetic lethality of the combination of bioavailable ATR and Wee1 inhibitors led to tumor remission and inhibited metastasis with minimal side effects. ATR and Wee1 inhibition had a higher synergistic effect in cancer stem cells than in bulk cancer cells, compensating for the lower sensitivity of cancer stem cells to the individual drugs. Mechanistically, the combination treatment caused cells with unrepaired or under-replicated DNA to enter mitosis leading to mitotic catastrophe. As these inhibitors of ATR and Wee1 are already in phase I/II clinical trials, this knowledge could soon be translated into the clinic, especially as we showed that the combination treatment targets a wide range of tumor cells. Particularly, the antimetastatic effect of combined Wee1/ATR inhibition and the low toxicity of ATR inhibitors compared with Chk1 inhibitors have great clinical potential.


Assuntos
Proteínas Mutadas de Ataxia Telangiectasia/antagonistas & inibidores , Neoplasias da Mama/tratamento farmacológico , Proteínas de Ciclo Celular/antagonistas & inibidores , Inibidores Enzimáticos/farmacologia , Proteínas de Neoplasias/antagonistas & inibidores , Células-Tronco Neoplásicas/enzimologia , Proteínas Tirosina Quinases/antagonistas & inibidores , Animais , Proteínas Mutadas de Ataxia Telangiectasia/metabolismo , Neoplasias da Mama/enzimologia , Neoplasias da Mama/patologia , Proteínas de Ciclo Celular/metabolismo , Linhagem Celular Tumoral , Feminino , Humanos , Camundongos , Camundongos Endogâmicos NOD , Metástase Neoplásica , Proteínas de Neoplasias/metabolismo , Células-Tronco Neoplásicas/patologia , Proteínas Tirosina Quinases/metabolismo , Ensaios Antitumorais Modelo de Xenoenxerto
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