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2.
PLoS Genet ; 16(12): e1009201, 2020 12.
Artigo em Inglês | MEDLINE | ID: mdl-33383577

RESUMO

Conjunctival melanoma (CJM) is a rare but potentially lethal and highly-recurrent cancer of the eye. Similar to cutaneous melanoma (CM), it originates from melanocytes. Unlike CM, however, CJM is relatively poorly characterized from a genomic point of view. To fill this knowledge gap and gain insight into the genomic nature of CJM, we performed whole-exome (WES) or whole-genome sequencing (WGS) of tumor-normal tissue pairs in 14 affected individuals, as well as RNA sequencing in a subset of 11 tumor tissues. Our results show that, similarly to CM, CJM is also characterized by a very high mutation load, composed of approximately 500 somatic mutations in exonic regions. This, as well as the presence of a UV light-induced mutational signature, are clear signs of the role of sunlight in CJM tumorigenesis. In addition, the genomic classification of CM proposed by TCGA seems to be well-applicable to CJM, with the presence of four typical subclasses defined on the basis of the most frequently mutated genes: BRAF, NF1, RAS, and triple wild-type. In line with these results, transcriptomic analyses revealed similarities with CM as well, namely the presence of a transcriptomic subtype enriched for immune genes and a subtype enriched for genes associated with keratins and epithelial functions. Finally, in seven tumors we detected somatic mutations in ACSS3, a possible new candidate oncogene. Transfected conjunctival melanoma cells overexpressing mutant ACSS3 showed higher proliferative activity, supporting the direct involvement of this gene in the tumorigenesis of CJM. Altogether, our results provide the first unbiased and complete genomic and transcriptomic classification of CJM.


Assuntos
Neoplasias da Túnica Conjuntiva/genética , Variações do Número de Cópias de DNA , Melanoma/genética , Mutação , Transcriptoma , Linhagem Celular Tumoral , Neoplasias da Túnica Conjuntiva/metabolismo , Feminino , Humanos , Masculino , Melanoma/metabolismo , Pessoa de Meia-Idade , Neurofibromina 1/genética , Proteínas Proto-Oncogênicas B-raf/genética , Proteínas ras/genética
3.
Arq Bras Cir Dig ; 33(3): e1524, 2020.
Artigo em Inglês, Português | MEDLINE | ID: mdl-33331426

RESUMO

BACKGROUND: KRAS mutations are important events in colorectal carcinogenesis, as well as negative predictors of response to EGFR inhibitors treatment. AIM: To investigate the association of clinical-pathological features with KRAS mutations in colorectal cancer patients treated. METHODS: Data from 69 patients with colorectal cancer either metastatic at diagnosis or later, were retrospectively analyzed. The direct sequencing and pyrosequencing techniques were related to KRAS exon 2. The mutation diagnosis and its type were determined. RESULTS: KRAS mutation was identified in 43.4% of patients. The most common was c.35G>T (p.G12V), c.35G>A (p.G12D) and c.38G>A (p.G13D). No correlation was found between KRAS mutation and age (p=0.646) or gender (p=0.815). However, mutated group had higher CEA levels at admission (p=0.048) and codon 13 mutation was associated with involvement of more than one metastatic site in disease progression (p=0.029). Although there was no association between primary tumor site and mutation diagnosis (p=0.568), primary colon was associated with worse overall survival (p=0.009). CONCLUSION: The KRAS mutation was identified in almost half of patients. Mutated KRAS group had higher levels of CEA at admission and the mutation at codon 13 was associated with involvement of more than one metastatic site in the course of the disease. Colon disease was associated with the worst overall survival.


Assuntos
Neoplasias Colorretais/genética , Proteínas Proto-Oncogênicas p21(ras) , Proteínas Proto-Oncogênicas/metabolismo , Adulto , Idoso , Idoso de 80 Anos ou mais , Neoplasias Colorretais/patologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Mutação , Proteínas Proto-Oncogênicas/genética , Proteínas Proto-Oncogênicas p21(ras)/genética , Estudos Retrospectivos , Proteínas ras/genética
4.
PLoS One ; 15(12): e0243975, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33320912

RESUMO

4-Hexylresorcinol (4HR) is used as a food preservative and an ingredient of toothpaste and cosmetics. The present study was performed using 233 antisera to determine the changes in protein expression induced by 4HR in human umbilical cord vein endothelial cells (HUVECs), and evaluated the 4HR-induced effects in comparison with previous results (Kim et al., 2019). Similar to RAW 264.7 cells, 4HR-treated HUVECs showed decreases in the expression of the proliferation-related proteins, cMyc/MAX/MAD network proteins, p53/RB and Wnt/ß-catenin signaling, and they showed inactivation of DNA transcription and protein translation compared to the untreated controls. 4HR upregulated growth factors (TGF-ß1, ß2, ß3, SMAD2/3, SMAD4, HGF-α, Met, IGF-1) and RAS signaling proteins (RAF-B, p38, p-p38, p-ERK-1, and Rab-1), and induced stronger expression of the cellular protection-, survival-, and differentiation-related proteins in HUVECs than in RAW 264.7 cells. 4HR suppressed NFkB signaling in a manner that suggests potential anti-inflammatory and wound healing effects by reducing M1 macrophage polarization and increasing M2 macrophage polarization in both cells. 4HR-treated HUVECs tended to increase the ER stress mediators by upregulating eIF2AK3, ATF4, ATF6, lysozyme, and LC3 and downregulating eIF2α and GADD153 (CHOP), resulting in PARP-1/AIF-mediated apoptosis. These results indicate that 4HR has similar effects on the protein expression of HUVECs and RAW 264.7 cells, but their protein expression levels differ according to cell types. The 4HR-treated cells showed global protein expression characteristic of anticancer and wound healing effects, which could be alleviated simultaneously by other proteins exerting opposite functions. These results suggest that although 4HR has similar effects on the global protein expression of HUVECs and RAW 264.7 cells, the 4HR-induced molecular interferences in those cells are complex enough to produce variable protein expression, leading different cell functions. Moreover, HUVECs have stronger wound healing potential to overcome the impact induced by 4HR than RAW 264.7 cells.


Assuntos
Anti-Helmínticos/farmacologia , Hexilresorcinol/farmacologia , Células Endoteliais da Veia Umbilical Humana/efeitos dos fármacos , Proteoma/química , Animais , Apoptose , Autofagia , Proliferação de Células , Células Endoteliais da Veia Umbilical Humana/metabolismo , Humanos , Camundongos , NF-kappa B/genética , NF-kappa B/metabolismo , Proteoma/genética , Proteoma/metabolismo , Células RAW 264.7 , Via de Sinalização Wnt , Proteínas ras/genética , Proteínas ras/metabolismo
5.
Lancet Oncol ; 21(11): 1478-1488, 2020 11.
Artigo em Inglês | MEDLINE | ID: mdl-33128873

RESUMO

BACKGROUND: CH5126766 (also known as VS-6766, and previously named RO5126766), a novel MEK-pan-RAF inhibitor, has shown antitumour activity across various solid tumours; however, its initial development was limited by toxicity. We aimed to investigate the safety and toxicity profile of intermittent dosing schedules of CH5126766, and the antitumour activity of this drug in patients with solid tumours and multiple myeloma harbouring RAS-RAF-MEK pathway mutations. METHODS: We did a single-centre, open-label, phase 1 dose-escalation and basket dose-expansion study at the Royal Marsden National Health Service Foundation Trust (London, UK). Patients were eligible for the study if they were aged 18 years or older, had cancers that were refractory to conventional treatment or for which no conventional therapy existed, and if they had a WHO performance status score of 0 or 1. For the dose-escalation phase, eligible patients had histologically or cytologically confirmed advanced or metastatic solid tumours. For the basket dose-expansion phase, eligible patients had advanced or metastatic solid tumours or multiple myeloma harbouring RAS-RAF-MEK pathway mutations. During the dose-escalation phase, we evaluated three intermittent oral schedules (28-day cycles) in patients with solid tumours: (1) 4·0 mg or 3·2 mg CH5126766 three times per week; (2) 4·0 mg CH5126766 twice per week; and (3) toxicity-guided dose interruption schedule, in which treatment at the recommended phase 2 dose (4·0 mg CH5126766 twice per week) was de-escalated to 3 weeks on followed by 1 week off if patients had prespecified toxic effects (grade 2 or worse diarrhoea, rash, or creatinine phosphokinase elevation). In the basket dose-expansion phase, we evaluated antitumour activity at the recommended phase 2 dose, determined from the dose-escalation phase, in biomarker-selected patients. The primary endpoints were the recommended phase 2 dose at which no more than one out of six patients had a treatment-related dose-limiting toxicity, and the safety and toxicity profile of each dosing schedule. The key secondary endpoint was investigator-assessed response rate in the dose-expansion phase. Patients who received at least one dose of the study drug were evaluable for safety and patients who received one cycle of the study drug and underwent baseline disease assessment were evaluable for response. This trial is registered with ClinicalTrials.gov, NCT02407509. FINDINGS: Between June 5, 2013, and Jan 10, 2019, 58 eligible patients were enrolled to the study: 29 patients with solid tumours were included in the dose-escalation cohort and 29 patients with solid tumours or multiple myeloma were included in the basket dose-expansion cohort (12 non-small-cell lung cancer, five gynaecological malignancy, four colorectal cancer, one melanoma, and seven multiple myeloma). Median follow-up at the time of data cutoff was 2·3 months (IQR 1·6-3·5). Dose-limiting toxicities included grade 3 bilateral retinal pigment epithelial detachment in one patient who received 4·0 mg CH5126766 three times per week, and grade 3 rash (in two patients) and grade 3 creatinine phosphokinase elevation (in one patient) in those who received 3·2 mg CH5126766 three times per week. 4·0 mg CH5126766 twice per week (on Monday and Thursday or Tuesday and Friday) was established as the recommended phase 2 dose. The most common grade 3-4 treatment-related adverse events were rash (11 [19%] patients), creatinine phosphokinase elevation (six [11%]), hypoalbuminaemia (six [11%]), and fatigue (four [7%]). Five (9%) patients had serious treatment-related adverse events. There were no treatment-related deaths. Eight (14%) of 57 patients died during the trial due to disease progression. Seven (27% [95% CI 11·6-47·8]) of 26 response-evaluable patients in the basket expansion achieved objective responses. INTERPRETATION: To our knowledge, this is the first study to show that highly intermittent schedules of a RAF-MEK inhibitor has antitumour activity across various cancers with RAF-RAS-MEK pathway mutations, and that this inhibitor is tolerable. CH5126766 used as a monotherapy and in combination regimens warrants further evaluation. FUNDING: Chugai Pharmaceutical.


Assuntos
Cumarínicos/administração & dosagem , Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos/patologia , Mieloma Múltiplo/tratamento farmacológico , Inibidores de Proteínas Quinases/administração & dosagem , Administração Oral , Adulto , Idoso , Cumarínicos/efeitos adversos , Relação Dose-Resposta a Droga , Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos/classificação , Feminino , Humanos , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Masculino , Pessoa de Meia-Idade , Mieloma Múltiplo/genética , Mieloma Múltiplo/patologia , Inibidores de Proteínas Quinases/efeitos adversos , Quinases raf/genética , Proteínas ras/genética
6.
Nat Commun ; 11(1): 4673, 2020 09 16.
Artigo em Inglês | MEDLINE | ID: mdl-32938917

RESUMO

RAS-MAPK signaling mediates processes critical to normal development including cell proliferation, survival, and differentiation. Germline mutation of RAS-MAPK genes lead to the Noonan-spectrum of syndromes. Here, we present a patient affected by a 6p-interstitial microdeletion with unknown underlying molecular etiology. Examination of 6p-interstitial microdeletion cases reveals shared clinical features consistent with Noonan-spectrum disorders including short stature, facial dysmorphia and cardiovascular abnormalities. We find the RAS-responsive element binding protein-1 (RREB1) is the common deleted gene in multiple 6p-interstitial microdeletion cases. Rreb1 hemizygous mice display orbital hypertelorism and cardiac hypertrophy phenocopying the human syndrome. Rreb1 haploinsufficiency leads to sensitization of MAPK signaling. Rreb1 recruits Sin3a and Kdm1a to control H3K4 methylation at MAPK pathway gene promoters. Haploinsufficiency of SIN3A and mutations in KDM1A cause syndromes similar to RREB1 haploinsufficiency suggesting genetic perturbation of the RREB1-SIN3A-KDM1A complex represents a new category of RASopathy-like syndromes arising through epigenetic reprogramming of MAPK pathway genes.


Assuntos
Proteínas de Ligação a DNA/genética , Haploinsuficiência , Sistema de Sinalização das MAP Quinases/genética , Síndrome de Noonan/etiologia , Fatores de Transcrição/genética , Proteínas ras/metabolismo , Anormalidades Múltiplas/genética , Animais , Deleção Cromossômica , Cromossomos Humanos Par 6 , Proteínas de Ligação a DNA/metabolismo , Epigênese Genética , Feminino , Fatores de Crescimento de Fibroblastos/genética , Fatores de Crescimento de Fibroblastos/metabolismo , Histona Desmetilases/genética , Histona Desmetilases/metabolismo , Histonas/metabolismo , Humanos , Masculino , Metilação , Camundongos Endogâmicos C57BL , Camundongos Knockout , Complexo Correpressor Histona Desacetilase e Sin3/genética , Complexo Correpressor Histona Desacetilase e Sin3/metabolismo , Fatores de Transcrição/metabolismo , Proteínas ras/genética
7.
Nat Commun ; 11(1): 4653, 2020 09 16.
Artigo em Inglês | MEDLINE | ID: mdl-32938923

RESUMO

Cancer cells demand excess nutrients to support their proliferation, but how tumours exploit extracellular amino acids during systemic metabolic perturbations remain incompletely understood. Here, we use a Drosophila model of high-sugar diet (HSD)-enhanced tumourigenesis to uncover a systemic host-tumour metabolic circuit that supports tumour growth. We demonstrate coordinate induction of systemic muscle wasting with tumour-autonomous Yorkie-mediated SLC36-family amino acid transporter expression as a proline-scavenging programme to drive tumourigenesis. We identify Indole-3-propionic acid as an optimal amino acid derivative to rationally target the proline-dependency of tumour growth. Insights from this whole-animal Drosophila model provide a powerful approach towards the identification and therapeutic exploitation of the amino acid vulnerabilities of tumourigenesis in the context of a perturbed systemic metabolic network.


Assuntos
Açúcares da Dieta/efeitos adversos , Músculo Esquelético/efeitos dos fármacos , Músculo Esquelético/fisiopatologia , Neoplasias Experimentais/fisiopatologia , Prolina/metabolismo , Sistemas de Transporte de Aminoácidos/genética , Sistemas de Transporte de Aminoácidos/metabolismo , Animais , Animais Geneticamente Modificados , Carcinogênese , Proteínas de Drosophila/genética , Proteínas de Drosophila/metabolismo , Drosophila melanogaster/genética , Drosophila melanogaster/metabolismo , Fatores de Crescimento de Fibroblastos/genética , Fatores de Crescimento de Fibroblastos/metabolismo , Perfilação da Expressão Gênica , Hemolinfa/efeitos dos fármacos , Hemolinfa/metabolismo , Larva , Debilidade Muscular/induzido quimicamente , Debilidade Muscular/patologia , Atrofia Muscular/induzido quimicamente , Atrofia Muscular/patologia , Neoplasias Experimentais/etiologia , Proteínas Nucleares/genética , Receptores Proteína Tirosina Quinases/metabolismo , Transativadores/genética , Proteínas ras/genética
8.
Adv Cancer Res ; 148: 69-146, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32723567

RESUMO

RAS was identified as a human oncogene in the early 1980s and subsequently found to be mutated in nearly 30% of all human cancers. More importantly, RAS plays a central role in driving tumor development and maintenance. Despite decades of effort, there remain no FDA approved drugs that directly inhibit RAS. The prevalence of RAS mutations in cancer and the lack of effective anti-RAS therapies stem from RAS' core role in growth factor signaling, unique structural features, and biochemistry. However, recent advances have brought promising new drugs to clinical trials and shone a ray of hope in the field. Here, we will exposit the details of RAS biology that illustrate its key role in cell signaling and shed light on the difficulties in therapeutically targeting RAS. Furthermore, past and current efforts to develop RAS inhibitors will be discussed in depth.


Assuntos
Antineoplásicos/uso terapêutico , Neoplasias/tratamento farmacológico , Neoplasias/metabolismo , Proteínas ras/metabolismo , Animais , Antineoplásicos/farmacologia , Humanos , Terapia de Alvo Molecular , Mutação , Neoplasias/patologia , Oncogenes , Transdução de Sinais/fisiologia , Proteínas ras/antagonistas & inibidores , Proteínas ras/genética
9.
Am J Hum Genet ; 107(3): 499-513, 2020 09 03.
Artigo em Inglês | MEDLINE | ID: mdl-32721402

RESUMO

Signal transduction through the RAF-MEK-ERK pathway, the first described mitogen-associated protein kinase (MAPK) cascade, mediates multiple cellular processes and participates in early and late developmental programs. Aberrant signaling through this cascade contributes to oncogenesis and underlies the RASopathies, a family of cancer-prone disorders. Here, we report that de novo missense variants in MAPK1, encoding the mitogen-activated protein kinase 1 (i.e., extracellular signal-regulated protein kinase 2, ERK2), cause a neurodevelopmental disease within the RASopathy phenotypic spectrum, reminiscent of Noonan syndrome in some subjects. Pathogenic variants promote increased phosphorylation of the kinase, which enhances translocation to the nucleus and boosts MAPK signaling in vitro and in vivo. Two variant classes are identified, one of which directly disrupts binding to MKP3, a dual-specificity protein phosphatase negatively regulating ERK function. Importantly, signal dysregulation driven by pathogenic MAPK1 variants is stimulus reliant and retains dependence on MEK activity. Our data support a model in which the identified pathogenic variants operate with counteracting effects on MAPK1 function by differentially impacting the ability of the kinase to interact with regulators and substrates, which likely explains the minor role of these variants as driver events contributing to oncogenesis. After nearly 20 years from the discovery of the first gene implicated in Noonan syndrome, PTPN11, the last tier of the MAPK cascade joins the group of genes mutated in RASopathies.


Assuntos
Carcinogênese/genética , Proteína Quinase 1 Ativada por Mitógeno/genética , Transtornos do Neurodesenvolvimento/genética , Síndrome de Noonan/genética , Pré-Escolar , Feminino , Humanos , Sistema de Sinalização das MAP Quinases/genética , Masculino , Mutação de Sentido Incorreto/genética , Transtornos do Neurodesenvolvimento/patologia , Síndrome de Noonan/fisiopatologia , Fenótipo , Proteína Tirosina Fosfatase não Receptora Tipo 11/genética , Transdução de Sinais , Sequenciamento Completo do Exoma , Proteínas ras/genética
10.
Nat Commun ; 11(1): 3409, 2020 07 08.
Artigo em Inglês | MEDLINE | ID: mdl-32641778

RESUMO

Pancreatic ductal adenocarcinoma (PDAC) is associated with high mortality and therapy resistance. Here, we show that low expression of κB-Ras GTPases is frequently detected in PDAC and correlates with higher histologic grade. In a model of KRasG12D-driven PDAC, loss of κB-Ras accelerates tumour development and shortens median survival. κB-Ras deficiency promotes acinar-to-ductal metaplasia (ADM) during tumour initiation as well as tumour progression through intrinsic effects on proliferation and invasion. κB-Ras proteins are also required for acinar regeneration after pancreatitis, demonstrating a general role in control of plasticity. Molecularly, upregulation of Ral GTPase activity and Sox9 expression underlies the observed phenotypes, identifying a previously unrecognized function of Ral signalling in ADM. Our results provide evidence for a tumour suppressive role of κB-Ras proteins and highlight low κB-Ras levels and consequent loss of Ral control as risk factors, thus emphasizing the necessity for therapeutic options that allow interference with Ral-driven signalling.


Assuntos
Células Acinares/metabolismo , Carcinoma Ductal Pancreático/genética , GTP Fosfo-Hidrolases/genética , Neoplasias Pancreáticas/genética , Pancreatite/genética , Proteínas/genética , Células Acinares/patologia , Idoso , Animais , Carcinoma Ductal Pancreático/metabolismo , Carcinoma Ductal Pancreático/patologia , Linhagem Celular Tumoral , Feminino , GTP Fosfo-Hidrolases/metabolismo , Regulação da Expressão Gênica , Humanos , Proteínas I-kappa B/genética , Proteínas I-kappa B/metabolismo , Estimativa de Kaplan-Meier , Masculino , Metaplasia/genética , Metaplasia/metabolismo , Camundongos Endogâmicos C57BL , Camundongos Knockout , Pessoa de Meia-Idade , Neoplasias Pancreáticas/metabolismo , Neoplasias Pancreáticas/patologia , Pancreatite/metabolismo , Proteínas/metabolismo , Fatores de Transcrição SOX9/genética , Fatores de Transcrição SOX9/metabolismo , Proteínas ral de Ligação ao GTP/genética , Proteínas ral de Ligação ao GTP/metabolismo , Proteínas ras/genética , Proteínas ras/metabolismo
11.
Am J Chin Med ; 48(5): 1221-1241, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32668964

RESUMO

Tamoxifen is one of the most common hormone therapy drug for estrogen receptor (ER)-positive breast cancer. Tumor cells with drug resistance often cause recurrence and metastasis in cancer patients. Luteolin is a natural compound found from various types of vegetables and exhibit anticancer activity in different cancers. This study demonstrated that luteolin inhibits the proliferation and induces apoptosis of tamoxifen-resistant ER-positive breast cancer cells. Luteolin also causes cell cycle arrest at the G2/M phase and decreases mitochondrial membrane potential. Besides, luteolin reduces the levels of activated PI3K/AKT/mTOR signaling pathway. The combination treatment of luteolin and PI3K, AKT, or mTOR inhibitors synergistically increases apoptosis in tamoxifen-resistant ER-positive breast cancer cells. Ras gene family (K-Ras, H-Ras, and N-Ras), an activator of PI3K, was transcriptionally repressed by luteolin via induction of tumor suppressor mixed-lineage leukemia 3 (MLL3) expression. MLL3 increases the level of monomethylation of Histone 3 Lysine 4 on the enhancer and promoter region of Ras genes, thus causes repression of Ras expressions. Our finding implies that luteolin was a promising natural agent against tamoxifen resistance of breast cancer.


Assuntos
Apoptose/efeitos dos fármacos , Apoptose/genética , Neoplasias da Mama/genética , Neoplasias da Mama/patologia , Proteínas de Ligação a DNA/fisiologia , Expressão Gênica/efeitos dos fármacos , Luteolina/farmacologia , Antineoplásicos Fitogênicos , Linhagem Celular Tumoral , Proteínas de Ligação a DNA/genética , Regulação para Baixo/efeitos dos fármacos , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Feminino , Humanos , Metilação/efeitos dos fármacos , Fosfatidilinositol 3-Quinases/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Transdução de Sinais/efeitos dos fármacos , Serina-Treonina Quinases TOR , Tamoxifeno/farmacologia , Proteínas ras/genética , Proteínas ras/metabolismo
12.
Nat Commun ; 11(1): 3568, 2020 07 16.
Artigo em Inglês | MEDLINE | ID: mdl-32678085

RESUMO

Dissemination of transformed cells is a key process in metastasis. Despite its importance, how transformed cells disseminate from an intact tissue and enter the circulation is poorly understood. Here, we use a fully developed tissue, Drosophila midgut, and describe the morphologically distinct steps and the cellular events occurring over the course of RasV12-transformed cell dissemination. Notably, RasV12-transformed cells formed the Actin- and Cortactin-rich invasive protrusions that were important for breaching the extracellular matrix (ECM) and visceral muscle. Furthermore, we uncovered the essential roles of the mechanosensory channel Piezo in orchestrating dissemination of RasV12-transformed cells. Collectively, our study establishes an in vivo model for studying how transformed cells migrate out from a complex tissue and provides unique insights into the roles of Piezo in invasive cell behavior.


Assuntos
Proteínas de Drosophila/metabolismo , Canais Iônicos/metabolismo , Mecanotransdução Celular , Invasividade Neoplásica/patologia , Proteínas ras/metabolismo , Animais , Membrana Basal/metabolismo , Membrana Basal/patologia , Transformação Celular Neoplásica , Modelos Animais de Doenças , Drosophila , Proteínas de Drosophila/genética , Vesículas Extracelulares/metabolismo , Trato Gastrointestinal/patologia , Genes ras , Canais Iônicos/genética , Metástase Neoplásica/patologia , Podossomos/metabolismo , Proteínas ras/genética
13.
Proc Natl Acad Sci U S A ; 117(29): 16938-16948, 2020 07 21.
Artigo em Inglês | MEDLINE | ID: mdl-32616570

RESUMO

Despite nearly four decades of effort, broad inhibition of oncogenic RAS using small-molecule approaches has proven to be a major challenge. Here we describe the development of a pan-RAS biologic inhibitor composed of the RAS-RAP1-specific endopeptidase fused to the protein delivery machinery of diphtheria toxin. We show that this engineered chimeric toxin irreversibly cleaves and inactivates intracellular RAS at low picomolar concentrations terminating downstream signaling in receptor-bearing cells. Furthermore, we demonstrate in vivo target engagement and reduction of tumor burden in three mouse xenograft models driven by either wild-type or mutant RAS Intracellular delivery of a potent anti-RAS biologic through a receptor-mediated mechanism represents a promising approach to developing RAS therapeutics against a broad array of cancers.


Assuntos
Toxina Diftérica/metabolismo , Endopeptidases/metabolismo , Neoplasias Experimentais/tratamento farmacológico , Proteólise , Proteínas rap1 de Ligação ao GTP/metabolismo , Proteínas ras/metabolismo , Animais , Antineoplásicos/uso terapêutico , Células Cultivadas , Toxina Diftérica/química , Toxina Diftérica/genética , Endopeptidases/química , Endopeptidases/genética , Feminino , Células HCT116 , Humanos , Masculino , Camundongos , Camundongos Nus , Mutação , Sinais Direcionadores de Proteínas , Proteínas Recombinantes/uso terapêutico , Proteínas ras/genética
14.
Nat Rev Drug Discov ; 19(8): 533-552, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32528145

RESUMO

RAS (KRAS, NRAS and HRAS) is the most frequently mutated gene family in cancers, and, consequently, investigators have sought an effective RAS inhibitor for more than three decades. Even 10 years ago, RAS inhibitors were so elusive that RAS was termed 'undruggable'. Now, with the success of allele-specific covalent inhibitors against the most frequently mutated version of RAS in non-small-cell lung cancer, KRASG12C, we have the opportunity to evaluate the best therapeutic strategies to treat RAS-driven cancers. Mutation-specific biochemical properties, as well as the tissue of origin, are likely to affect the effectiveness of such treatments. Currently, direct inhibition of mutant RAS through allele-specific inhibitors provides the best therapeutic approach. Therapies that target RAS-activating pathways or RAS effector pathways could be combined with these direct RAS inhibitors, immune checkpoint inhibitors or T cell-targeting approaches to treat RAS-mutant tumours. Here we review recent advances in therapies that target mutant RAS proteins and discuss the future challenges of these therapies, including combination strategies.


Assuntos
Antineoplásicos/farmacologia , Sistemas de Liberação de Medicamentos , Neoplasias/tratamento farmacológico , Proteínas ras/antagonistas & inibidores , Animais , Humanos , Mutação , Neoplasias/genética , Proteínas ras/genética
15.
PLoS Genet ; 16(6): e1008838, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32544191

RESUMO

Reactive oxygen species (ROS) are signalling molecules whose study in intact organisms has been hampered by their potential toxicity. This has prevented a full understanding of their role in organismal processes such as development, aging and disease. In Caenorhabditis elegans, the development of the vulva is regulated by a signalling cascade that includes LET-60ras (homologue of mammalian Ras), MPK-1 (ERK1/2) and LIN-1 (an ETS transcription factor). We show that both mitochondrial and cytoplasmic ROS act on a gain-of-function (gf) mutant of the LET-60ras protein through a redox-sensitive cysteine (C118) previously identified in mammals. We show that the prooxidant paraquat as well as isp-1, nuo-6 and sod-2 mutants, which increase mitochondrial ROS, inhibit the activity of LET-60rasgf on vulval development. In contrast, the antioxidant NAC and loss of sod-1, both of which decrease cytoplasmic H202, enhance the activity of LET-60rasgf. CRISPR replacement of C118 with a non-oxidizable serine (C118S) stimulates LET-60rasgf activity, whereas replacement of C118 with aspartate (C118D), which mimics a strongly oxidised cysteine, inhibits LET-60rasgf. These data strongly suggest that C118 is oxidized by cytoplasmic H202 generated from dismutation of mitochondrial and/or cytoplasmic superoxide, and that this oxidation inhibits LET-60ras. This contrasts with results in cultured mammalian cells where it is mostly nitric oxide, which is not found in worms, that oxidizes C118 and activates Ras. Interestingly, PQ, NAC and the C118S mutation do not act on the phosphorylation of MPK-1, suggesting that oxidation of LET-60ras acts on an as yet uncharacterized MPK-1-independent pathway. We also show that elevated cytoplasmic superoxide promotes vulva formation independently of C118 of LET-60ras and downstream of LIN-1. Finally, we uncover a role for the NADPH oxidases (BLI-3 and DUOX-2) and their redox-sensitive activator CED-10rac in stimulating vulva development. Thus, there are at least three genetically separable pathways by which ROS regulates vulval development.


Assuntos
Proteínas de Caenorhabditis elegans/genética , Caenorhabditis elegans/crescimento & desenvolvimento , Regulação da Expressão Gênica no Desenvolvimento , Peróxidos/metabolismo , Vulva/crescimento & desenvolvimento , Proteínas ras/genética , Animais , Animais Geneticamente Modificados , Caenorhabditis elegans/genética , Proteínas de Caenorhabditis elegans/metabolismo , Feminino , Mutação com Ganho de Função , Genes de Helmintos/genética , Oxirredução , Oxirredutases/metabolismo , Peróxidos/análise , Transdução de Sinais/genética , Fatores de Transcrição/metabolismo , Proteínas rac de Ligação ao GTP/metabolismo , Proteínas ras/metabolismo
16.
PLoS Genet ; 16(6): e1008715, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32559233

RESUMO

Dysregulation of the Ras oncogene in development causes developmental disorders, "Rasopathies," whereas mutational activation or amplification of Ras in differentiated tissues causes cancer. Rabex-5 (also called RabGEF1) inhibits Ras by promoting Ras mono- and di-ubiquitination. We report here that Rabex-5-mediated Ras ubiquitination requires Ras Tyrosine 4 (Y4), a site of known phosphorylation. Ras substitution mutants insensitive to Y4 phosphorylation did not undergo Rabex-5-mediated ubiquitination in cells and exhibited Ras gain-of-function phenotypes in vivo. Ras Y4 phosphomimic substitution increased Rabex-5-mediated ubiquitination in cells. Y4 phosphomimic substitution in oncogenic Ras blocked the morphological phenotypes associated with oncogenic Ras in vivo dependent on the presence of Rabex-5. We developed polyclonal antibodies raised against an N-terminal Ras peptide phosphorylated at Y4. These anti-phospho-Y4 antibodies showed dramatic recognition of recombinant wild-type Ras and RasG12V proteins when incubated with JAK2 or SRC kinases but not of RasY4F or RasY4F,G12V recombinant proteins suggesting that JAK2 and SRC could promote phosphorylation of Ras proteins at Y4 in vitro. Anti-phospho-Y4 antibodies also showed recognition of RasG12V protein, but not wild-type Ras, when incubated with EGFR. A role for JAK2, SRC, and EGFR (kinases with well-known roles to activate signaling through Ras), to promote Ras Y4 phosphorylation could represent a feedback mechanism to limit Ras activation and thus establish Ras homeostasis. Notably, rare variants of Ras at Y4 have been found in cerebellar glioblastomas. Therefore, our work identifies a physiologically relevant Ras ubiquitination signal and highlights a requirement for Y4 for Ras inhibition by Rabex-5 to maintain Ras pathway homeostasis and to prevent tissue transformation.


Assuntos
Proteínas de Drosophila/metabolismo , Transdução de Sinais , Ubiquitina-Proteína Ligases/metabolismo , Proteínas ras/metabolismo , Animais , Células Cultivadas , Sequência Conservada , Drosophila , Receptores ErbB/metabolismo , Retroalimentação Fisiológica , Janus Quinase 2/metabolismo , Fosforilação , Tirosina/química , Tirosina/genética , Ubiquitinação , Proteínas ras/química , Proteínas ras/genética , Quinases da Família src/metabolismo
17.
J Cancer Res Clin Oncol ; 146(8): 2077-2087, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32561975

RESUMO

PURPOSE: Although biomarkers for patients with metastatic colorectal cancer exist, the benefit patients with RAS mutated tumors derive from established regimens is unclear. METHODS: Efficacy of therapeutic strategies available for RAS mutated patients (addition of chemotherapeutic agents and/or anti angiogenic agents) were investigated in fourteen randomized controlled phase III trials at trial level by meta-analysing individual study hazard ratios and 95% confidence intervals (95% CI) for overall survival (OS) and progression free survival (PFS). RESULTS: 6810 of 10,748 patients (63.3%) were available (48.5% RAS wildtype, 51.5% RAS mutated). Across all treatment lines, additional treatment efficacy (chemotherapy and/or anti angiogenic agents) was significantly smaller in RAS mutated compared to wildtype tumors for OS and PFS. In detail, patients with RAS mutated metastatic colorectal cancer derived significant benefit in PFS but not in OS by the addition of either chemotherapy or anti angiogenic agents to the respective comparator. In patients with RAS wildtype metastatic colorectal cancer, PFS and OS were improved by the addition of chemotherapy or anti angiogenic agent. CONCLUSION: The therapeutic benefit of additional substances is less distinct in patients with RAS mutated as compared to RAS wildtype metastatic colorectal cancer, especially with regard to OS.


Assuntos
Inibidores da Angiogênese/uso terapêutico , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Neoplasias Colorretais/tratamento farmacológico , Neoplasias Colorretais/genética , Mutação , Proteínas ras/genética , Inibidores da Angiogênese/administração & dosagem , Ensaios Clínicos Fase III como Assunto , Genes ras , Humanos , Ensaios Clínicos Controlados Aleatórios como Assunto
18.
Nat Commun ; 11(1): 2189, 2020 05 04.
Artigo em Inglês | MEDLINE | ID: mdl-32366847

RESUMO

While most testicular germ cell tumours (TGCTs) exhibit exquisite sensitivity to platinum chemotherapy, ~10% are platinum resistant. To gain insight into the underlying mechanisms, we undertake whole exome sequencing and copy number analysis in 40 tumours from 26 cases with platinum-resistant TGCT, and combine this with published genomic data on an additional 624 TGCTs. We integrate analyses for driver mutations, mutational burden, global, arm-level and focal copy number (CN) events, and SNV and CN signatures. Albeit preliminary and observational in nature, these analyses provide support for a possible mechanistic link between early driver mutations in RAS and KIT and the widespread copy number events by which TGCT is characterised.


Assuntos
Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Genômica/métodos , Neoplasias Embrionárias de Células Germinativas/tratamento farmacológico , Platina/uso terapêutico , Neoplasias Testiculares/tratamento farmacológico , Variações do Número de Cópias de DNA , Predisposição Genética para Doença/genética , Humanos , Masculino , Mutação , Neoplasias Embrionárias de Células Germinativas/genética , Neoplasias Embrionárias de Células Germinativas/metabolismo , Compostos Organoplatínicos/uso terapêutico , Proteínas Proto-Oncogênicas c-kit/genética , Proteínas Proto-Oncogênicas c-kit/metabolismo , Transdução de Sinais/genética , Neoplasias Testiculares/genética , Neoplasias Testiculares/metabolismo , Sequenciamento Completo do Exoma/métodos , Proteínas ras/genética , Proteínas ras/metabolismo
19.
Am J Physiol Endocrinol Metab ; 319(1): E232-E244, 2020 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-32369417

RESUMO

Voltage-gated Ca2+ (CaV) channels are expressed in endocrine cells where they contribute to hormone secretion. Diverse chemical messengers, including epidermal growth factor (EGF), are known to affect the expression of CaV channels. Previous studies have shown that EGF increases Ca2+ currents in GH3 pituitary cells by increasing the number of high voltage-activated (HVA) CaV channels at the cell membrane, which results in enhanced prolactin (PRL) secretion. However, little is known regarding the mechanisms underlying this regulation. Here, we show that EGF actually increases the expression of the CaVα2δ-1 subunit, a key molecular component of HVA channels. The analysis of the gene promoter encoding CaVα2δ-1 (CACNA2D1) revealed binding sites for transcription factors activated by the Ras/Raf/MEK/ERK signaling cascade. Chromatin immunoprecipitation and site-directed mutagenesis showed that ELK-1 is crucial for the transcriptional regulation of CACNA2D1 in response to EGF. Furthermore, we found that EGF increases the membrane expression of CaVα2δ-1 and that ELK-1 overexpression increases HVA current density, whereas ELK-1 knockdown decreases the functional expression of the channels. Hormone release assays revealed that CaVα2δ-1 overexpression increases PRL secretion. These results suggest a mechanism for how EGF, by activating the Ras/Raf/MEK/ERK/ELK-1 pathway, may influence the expression of HVA channels and the secretory behavior of pituitary cells.


Assuntos
Canais de Cálcio Tipo L/genética , Fator de Crescimento Epidérmico/metabolismo , Regulação da Expressão Gênica , Sistema de Sinalização das MAP Quinases/genética , Proteínas Elk-1 do Domínio ets/genética , Quinases raf/genética , Proteínas ras/genética , Animais , Canais de Cálcio Tipo L/metabolismo , Linhagem Celular Tumoral , Imunoprecipitação da Cromatina , Proteína de Ligação ao Elemento de Resposta ao AMP Cíclico/genética , Proteína de Ligação ao Elemento de Resposta ao AMP Cíclico/metabolismo , Técnicas de Silenciamento de Genes , Mutagênese Sítio-Dirigida , Regiões Promotoras Genéticas , Ratos , Transdução de Sinais , Proteínas Elk-1 do Domínio ets/metabolismo , Quinases raf/metabolismo , Proteínas ras/metabolismo
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