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1.
Cell ; 181(6): 1395-1405.e11, 2020 06 11.
Artigo em Inglês | MEDLINE | ID: mdl-32531245

RESUMO

STK19 was proposed to be a cancer driver, and recent work by Yin et al. (2019) in Cell suggested that the frequently recurring STK19 D89N substitution represents a gain-of-function change, allowing increased phosphorylation of NRAS to enhance melanocyte transformation. Here we show that the STK19 gene has been incorrectly annotated, and that the expressed protein is 110 amino acids shorter than indicated by current databases. The "cancer driving" STK19 D89N substitution is thus outside the coding region. We also fail to detect evidence of the mutation affecting STK19 expression; instead, it is a UV signature mutation, found in the promoter of other genes as well. Furthermore, STK19 is exclusively nuclear and chromatin-associated, while no evidence for it being a kinase was found. The data in this Matters Arising article raise fundamental questions about the recently proposed role for STK19 in melanoma progression via a function as an NRAS kinase, suggested by Yin et al. (2019) in Cell. See also the response by Yin et al. (2020), published in this issue.


Assuntos
Melanoma , Recidiva Local de Neoplasia , GTP Fosfo-Hidrolases/metabolismo , Genes ras , Humanos , Melanoma/genética , Proteínas de Membrana/genética , Proteínas de Membrana/metabolismo , Mutação , Proteínas Nucleares , Fosforilação , Proteínas Serina-Treonina Quinases/genética , Transdução de Sinais
2.
Immunity ; 52(1): 14-16, 2020 01 14.
Artigo em Inglês | MEDLINE | ID: mdl-31951548

RESUMO

In the search for therapeutic combinations for the treatment of cancer, the pairing of targeted inhibitors of oncogenic driver pathways with immunotherapy has largely been overlooked. In Nature, Canon et al. (2019) describe how the novel KRAS-G12C inhibitor AMG 510 can potentiate immune rejection in combination with immune checkpoint blockade.


Assuntos
Antineoplásicos , Neoplasias , Humanos , Imunoterapia , Proteínas Proto-Oncogênicas p21(ras) , Evasão Tumoral
3.
Nature ; 616(7957): 563-573, 2023 04.
Artigo em Inglês | MEDLINE | ID: mdl-37046094

RESUMO

B cells are frequently found in the margins of solid tumours as organized follicles in ectopic lymphoid organs called tertiary lymphoid structures (TLS)1,2. Although TLS have been found to correlate with improved patient survival and response to immune checkpoint blockade (ICB), the underlying mechanisms of this association remain elusive1,2. Here we investigate lung-resident B cell responses in patients from the TRACERx 421 (Tracking Non-Small-Cell Lung Cancer Evolution Through Therapy) and other lung cancer cohorts, and in a recently established immunogenic mouse model for lung adenocarcinoma3. We find that both human and mouse lung adenocarcinomas elicit local germinal centre responses and tumour-binding antibodies, and further identify endogenous retrovirus (ERV) envelope glycoproteins as a dominant anti-tumour antibody target. ERV-targeting B cell responses are amplified by ICB in both humans and mice, and by targeted inhibition of KRAS(G12C) in the mouse model. ERV-reactive antibodies exert anti-tumour activity that extends survival in the mouse model, and ERV expression predicts the outcome of ICB in human lung adenocarcinoma. Finally, we find that effective immunotherapy in the mouse model requires CXCL13-dependent TLS formation. Conversely, therapeutic CXCL13 treatment potentiates anti-tumour immunity and synergizes with ICB. Our findings provide a possible mechanistic basis for the association of TLS with immunotherapy response.


Assuntos
Retrovirus Endógenos , Imunoterapia , Neoplasias Pulmonares , Animais , Humanos , Camundongos , Adenocarcinoma de Pulmão/imunologia , Adenocarcinoma de Pulmão/terapia , Adenocarcinoma de Pulmão/virologia , Carcinoma Pulmonar de Células não Pequenas/imunologia , Carcinoma Pulmonar de Células não Pequenas/terapia , Carcinoma Pulmonar de Células não Pequenas/virologia , Modelos Animais de Doenças , Retrovirus Endógenos/imunologia , Imunoterapia/métodos , Pulmão/imunologia , Neoplasias Pulmonares/imunologia , Neoplasias Pulmonares/terapia , Neoplasias Pulmonares/virologia , Microambiente Tumoral , Linfócitos B/imunologia , Estudos de Coortes , Anticorpos/imunologia , Anticorpos/uso terapêutico
4.
Cell ; 153(5): 1050-63, 2013 May 23.
Artigo em Inglês | MEDLINE | ID: mdl-23706742

RESUMO

RAS proteins are important direct activators of p110α, p110γ, and p110δ type I phosphoinositide 3-kinases (PI3Ks), interacting via an amino-terminal RAS-binding domain (RBD). Here, we investigate the regulation of the ubiquitous p110ß isoform of PI3K, implicated in G-protein-coupled receptor (GPCR) signaling, PTEN-loss-driven cancers, and thrombocyte function. Unexpectedly, RAS is unable to interact with p110ß, but instead RAC1 and CDC42 from the RHO subfamily of small GTPases bind and activate p110ß via its RBD. In fibroblasts, GPCRs couple to PI3K through Dock180/Elmo1-mediated RAC activation and subsequent interaction with p110ß. Cells from mice carrying mutations in the p110ß RBD show reduced PI3K activity and defective chemotaxis, and these mice are resistant to experimental lung fibrosis. These findings revise our understanding of the regulation of type I PI3K by showing that both RAS and RHO family GTPases directly regulate distinct ubiquitous PI3K isoforms and that RAC activates p110ß downstream of GPCRs.


Assuntos
Classe I de Fosfatidilinositol 3-Quinases/metabolismo , Fibroblastos/metabolismo , Transdução de Sinais , Proteínas ras/metabolismo , Animais , Quimiotaxia , Classe I de Fosfatidilinositol 3-Quinases/química , Fibrose/induzido quimicamente , Fibrose/prevenção & controle , Reguladores de Proteínas de Ligação ao GTP/metabolismo , Fatores de Troca do Nucleotídeo Guanina/metabolismo , Isoenzimas/metabolismo , Pulmão/patologia , Camundongos , Domínios e Motivos de Interação entre Proteínas , Proteínas rac1 de Ligação ao GTP/metabolismo , Proteínas ras/química
5.
Cell ; 149(3): 642-55, 2012 Apr 27.
Artigo em Inglês | MEDLINE | ID: mdl-22541434

RESUMO

Non-small cell lung cancer (NSCLC) is the most frequent cause of cancer deaths worldwide; nearly half contain mutations in the receptor tyrosine kinase/RAS pathway. Here we show that RAS-pathway mutant NSCLC cells depend on the transcription factor GATA2. Loss of GATA2 reduced the viability of NSCLC cells with RAS-pathway mutations, whereas wild-type cells were unaffected. Integrated gene expression and genome occupancy analyses revealed GATA2 regulation of the proteasome, and IL-1-signaling, and Rho-signaling pathways. These pathways were functionally significant, as reactivation rescued viability after GATA2 depletion. In a Kras-driven NSCLC mouse model, Gata2 loss dramatically reduced tumor development. Furthermore, Gata2 deletion in established Kras mutant tumors induced striking regression. Although GATA2 itself is likely undruggable, combined suppression of GATA2-regulated pathways with clinically approved inhibitors caused marked tumor clearance. Discovery of the nononcogene addiction of KRAS mutant lung cancers to GATA2 presents a network of druggable pathways for therapeutic exploitation.


Assuntos
Carcinoma Pulmonar de Células não Pequenas/metabolismo , Fator de Transcrição GATA2/metabolismo , Redes Reguladoras de Genes , Neoplasias Pulmonares/metabolismo , Proteínas Proto-Oncogênicas/metabolismo , Proteínas ras/metabolismo , Animais , Carcinoma Pulmonar de Células não Pequenas/patologia , Linhagem Celular Tumoral , Fator de Transcrição GATA2/genética , Regulação Neoplásica da Expressão Gênica , Técnicas de Silenciamento de Genes , Humanos , Neoplasias Pulmonares/patologia , Camundongos , Proteínas Proto-Oncogênicas/genética , Proteínas Proto-Oncogênicas p21(ras)/genética , Proteínas Proto-Oncogênicas p21(ras)/metabolismo , Transdução de Sinais , Proteínas ras/genética
6.
Immunity ; 47(6): 1083-1099.e6, 2017 12 19.
Artigo em Inglês | MEDLINE | ID: mdl-29246442

RESUMO

The immunosuppressive protein PD-L1 is upregulated in many cancers and contributes to evasion of the host immune system. The relative importance of the tumor microenvironment and cancer cell-intrinsic signaling in the regulation of PD-L1 expression remains unclear. We report that oncogenic RAS signaling can upregulate tumor cell PD-L1 expression through a mechanism involving increases in PD-L1 mRNA stability via modulation of the AU-rich element-binding protein tristetraprolin (TTP). TTP negatively regulates PD-L1 expression through AU-rich elements in the 3' UTR of PD-L1 mRNA. MEK signaling downstream of RAS leads to phosphorylation and inhibition of TTP by the kinase MK2. In human lung and colorectal tumors, RAS pathway activation is associated with elevated PD-L1 expression. In vivo, restoration of TTP expression enhances anti-tumor immunity dependent on degradation of PD-L1 mRNA. We demonstrate that RAS can drive cell-intrinsic PD-L1 expression, thus presenting therapeutic opportunities to reverse the innately immunoresistant phenotype of RAS mutant cancers.


Assuntos
Antígeno B7-H1/imunologia , Neoplasias Colorretais/imunologia , Regulação Neoplásica da Expressão Gênica , Neoplasias Pulmonares/imunologia , Proteínas Proto-Oncogênicas p21(ras)/imunologia , Tristetraprolina/imunologia , Evasão Tumoral , Animais , Antígeno B7-H1/genética , Linhagem Celular Tumoral , Neoplasias Colorretais/genética , Neoplasias Colorretais/patologia , Células Epiteliais/imunologia , Células Epiteliais/patologia , Feminino , Humanos , Peptídeos e Proteínas de Sinalização Intracelular/genética , Peptídeos e Proteínas de Sinalização Intracelular/imunologia , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/patologia , MAP Quinase Quinase Quinases/genética , MAP Quinase Quinase Quinases/imunologia , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Transplante de Neoplasias , Ligação Proteica , Proteínas Serina-Treonina Quinases/genética , Proteínas Serina-Treonina Quinases/imunologia , Proteínas Proto-Oncogênicas p21(ras)/genética , Clivagem do RNA , Estabilidade de RNA , RNA Mensageiro/genética , RNA Mensageiro/imunologia , Transdução de Sinais , Tristetraprolina/genética
8.
J Biol Chem ; 297(3): 101096, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34418430

RESUMO

Idiopathic pulmonary fibrosis (IPF) is the prototypic progressive fibrotic lung disease with a median survival of 2 to 4 years. Injury to and/or dysfunction of the alveolar epithelium is strongly implicated in IPF disease initiation, but the factors that determine whether fibrosis progresses rather than normal tissue repair occurs remain poorly understood. We previously demonstrated that zinc finger E-box-binding homeobox 1-mediated epithelial-mesenchymal transition in human alveolar epithelial type II (ATII) cells augments transforming growth factor-ß-induced profibrogenic responses in underlying lung fibroblasts via paracrine signaling. Here, we investigated bidirectional epithelial-mesenchymal crosstalk and its potential to drive fibrosis progression. RNA-Seq of lung fibroblasts exposed to conditioned media from ATII cells undergoing RAS-induced epithelial-mesenchymal transition identified many differentially expressed genes including those involved in cell migration and extracellular matrix regulation. We confirmed that paracrine signaling between RAS-activated ATII cells and fibroblasts augmented fibroblast recruitment and demonstrated that this involved a zinc finger E-box-binding homeobox 1-tissue plasminogen activator axis. In a reciprocal fashion, paracrine signaling from transforming growth factor-ß-activated lung fibroblasts or IPF fibroblasts induced RAS activation in ATII cells, at least partially through the secreted protein acidic and rich in cysteine, which may signal via the epithelial growth factor receptor via epithelial growth factor-like repeats. Together, these data identify that aberrant bidirectional epithelial-mesenchymal crosstalk in IPF drives a chronic feedback loop that maintains a wound-healing phenotype and provides self-sustaining profibrotic signals.


Assuntos
Transição Epitelial-Mesenquimal/fisiologia , Fibrose Pulmonar Idiopática/fisiopatologia , Movimento Celular , Células Epiteliais/metabolismo , Matriz Extracelular/metabolismo , Feminino , Fibroblastos/metabolismo , Fibrose/fisiopatologia , Humanos , Fibrose Pulmonar Idiopática/metabolismo , Pulmão/patologia , Masculino , Cultura Primária de Células , Fibrose Pulmonar/metabolismo , Ativador de Plasminogênio Tecidual/metabolismo , Fator de Crescimento Transformador beta/metabolismo , Homeobox 1 de Ligação a E-box em Dedo de Zinco/metabolismo
9.
Genet Med ; 23(9): 1636-1647, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34145395

RESUMO

PURPOSE: Much of the heredity of melanoma remains unexplained. We sought predisposing germline copy-number variants using a rare disease approach. METHODS: Whole-genome copy-number findings in patients with melanoma predisposition syndrome congenital melanocytic nevus were extrapolated to a sporadic melanoma cohort. Functional effects of duplications in PPP2R3B were investigated using immunohistochemistry, transcriptomics, and stable inducible cellular models, themselves characterized using RNAseq, quantitative real-time polymerase chain reaction (qRT-PCR), reverse phase protein arrays, immunoblotting, RNA interference, immunocytochemistry, proliferation, and migration assays. RESULTS: We identify here a previously unreported genetic susceptibility to melanoma and melanocytic nevi, familial duplications of gene PPP2R3B. This encodes PR70, a regulatory unit of critical phosphatase PP2A. Duplications increase expression of PR70 in human nevus, and increased expression in melanoma tissue correlates with survival via a nonimmunological mechanism. PPP2R3B overexpression induces pigment cell switching toward proliferation and away from migration. Importantly, this is independent of the known microphthalmia-associated transcription factor (MITF)-controlled switch, instead driven by C21orf91. Finally, C21orf91 is demonstrated to be downstream of MITF as well as PR70. CONCLUSION: This work confirms the power of a rare disease approach, identifying a previously unreported copy-number change predisposing to melanocytic neoplasia, and discovers C21orf91 as a potentially targetable hub in the control of phenotype switching.


Assuntos
Melanoma , Nevo , Neoplasias Cutâneas , Humanos , Imuno-Histoquímica , Melanoma/genética , Fenótipo , Neoplasias Cutâneas/genética
11.
Nature ; 505(7482): 212-7, 2014 Jan 09.
Artigo em Inglês | MEDLINE | ID: mdl-24305048

RESUMO

Non-small-cell lung cancer (NSCLC) is the most prevalent histological cancer subtype worldwide. As the majority of patients present with invasive, metastatic disease, it is vital to understand the basis for lung cancer progression. Hmga2 is highly expressed in metastatic lung adenocarcinoma, in which it contributes to cancer progression and metastasis. Here we show that Hmga2 promotes lung cancer progression in mouse and human cells by operating as a competing endogenous RNA (ceRNA) for the let-7 microRNA (miRNA) family. Hmga2 can promote the transformation of lung cancer cells independent of protein-coding function but dependent upon the presence of let-7 sites; this occurs without changes in the levels of let-7 isoforms, suggesting that Hmga2 affects let-7 activity by altering miRNA targeting. These effects are also observed in vivo, where Hmga2 ceRNA activity drives lung cancer growth, invasion and dissemination. Integrated analysis of miRNA target prediction algorithms and metastatic lung cancer gene expression data reveals the TGF-ß co-receptor Tgfbr3 (ref. 12) as a putative target of Hmga2 ceRNA function. Tgfbr3 expression is regulated by the Hmga2 ceRNA through differential recruitment to Argonaute 2 (Ago2), and TGF-ß signalling driven by Tgfbr3 is important for Hmga2 to promote lung cancer progression. Finally, analysis of NSCLC-patient gene-expression data reveals that HMGA2 and TGFBR3 are coordinately regulated in NSCLC-patient material, a vital corollary to ceRNA function. Taken together, these results suggest that Hmga2 promotes lung carcinogenesis both as a protein-coding gene and as a non-coding RNA; such dual-function regulation of gene-expression networks reflects a novel means by which oncogenes promote disease progression.


Assuntos
Progressão da Doença , Proteína HMGA2/genética , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/patologia , Animais , Proteínas Argonautas/metabolismo , Ligação Competitiva/genética , Carcinoma Pulmonar de Células não Pequenas/genética , Carcinoma Pulmonar de Células não Pequenas/patologia , Linhagem Celular Tumoral , Proliferação de Células , Modelos Animais de Doenças , Regulação Neoplásica da Expressão Gênica/genética , Humanos , Camundongos , MicroRNAs/genética , MicroRNAs/metabolismo , Invasividade Neoplásica/genética , Metástase Neoplásica/genética , Proteoglicanas/biossíntese , Proteoglicanas/deficiência , Proteoglicanas/genética , Isoformas de RNA/genética , Isoformas de RNA/metabolismo , Receptores de Fatores de Crescimento Transformadores beta/biossíntese , Receptores de Fatores de Crescimento Transformadores beta/deficiência , Receptores de Fatores de Crescimento Transformadores beta/genética , Transcrição Gênica/genética , Fator de Crescimento Transformador beta/metabolismo
12.
Mol Cell ; 44(6): 846-8, 2011 Dec 23.
Artigo em Inglês | MEDLINE | ID: mdl-22195959

RESUMO

In this issue of Molecular Cell, Hitosugi et al. (2011) show that the switch from oxidative phosphorylation to glycolysis in cancer cells is regulated by tyrosine phosphorylation of PDHK1.

13.
Biochem J ; 480(18): 1475-1478, 2023 Sep 27.
Artigo em Inglês | MEDLINE | ID: mdl-37732645
14.
Proc Natl Acad Sci U S A ; 113(46): 13156-13161, 2016 11 15.
Artigo em Inglês | MEDLINE | ID: mdl-27799550

RESUMO

Deficiency in PTEN (phosphatase and tensin homolog deleted on chromosome 10) is the underlying cause of PTEN hamartoma tumor syndrome and a wide variety of human cancers. In skin epidermis, we have previously identified an autocrine FGF signaling induced by loss of Pten in keratinocytes. In this study, we demonstrate that skin hyperplasia requires FGF receptor adaptor protein Frs2α and tyrosine phosphatase Shp2, two upstream regulators of Ras signaling. Although the PI3-kinase regulatory subunits p85α and p85ß are dispensable, the PI3-kinase catalytic subunit p110α requires interaction with Ras to promote hyperplasia in Pten-deficient skin, thus demonstrating an important cross-talk between Ras and PI3K pathways. Furthermore, genetic and pharmacological inhibition of Ras-MAPK pathway impeded epidermal hyperplasia in Pten animals. These results reveal a positive feedback loop connecting Pten and Ras pathways and suggest that FGF-activated Ras-MAPK pathway is an effective therapeutic target for preventing skin tumor induced by aberrant Pten signaling.


Assuntos
Fatores de Crescimento de Fibroblastos/metabolismo , PTEN Fosfo-Hidrolase/metabolismo , Neoplasias Cutâneas/metabolismo , Proteínas ras/metabolismo , Animais , Células Cultivadas , Queratinócitos/metabolismo , Proteínas de Membrana/metabolismo , Camundongos Transgênicos , Proteínas Quinases Ativadas por Mitógeno/metabolismo , PTEN Fosfo-Hidrolase/deficiência , PTEN Fosfo-Hidrolase/genética , Proteína Tirosina Fosfatase não Receptora Tipo 11/metabolismo , Transdução de Sinais , Pele/metabolismo
15.
Cell ; 133(7): 1292-1292.e1, 2008 Jun 27.
Artigo em Inglês | MEDLINE | ID: mdl-18585361
16.
Mol Cell ; 33(5): 627-38, 2009 Mar 13.
Artigo em Inglês | MEDLINE | ID: mdl-19285945

RESUMO

Mutations in PINK1 cause autosomal recessive Parkinson's disease. PINK1 is a mitochondrial kinase of unknown function. We investigated calcium homeostasis and mitochondrial function in PINK1-deficient mammalian neurons. We demonstrate physiologically that PINK1 regulates calcium efflux from the mitochondria via the mitochondrial Na(+)/Ca(2+) exchanger. PINK1 deficiency causes mitochondrial accumulation of calcium, resulting in mitochondrial calcium overload. We show that calcium overload stimulates reactive oxygen species (ROS) production via NADPH oxidase. ROS production inhibits the glucose transporter, reducing substrate delivery and causing impaired respiration. We demonstrate that impaired respiration may be restored by provision of mitochondrial complex I and II substrates. Taken together, reduced mitochondrial calcium capacity and increased ROS lower the threshold of opening of the mitochondrial permeability transition pore (mPTP) such that physiological calcium stimuli become sufficient to induce mPTP opening in PINK1-deficient cells. Our findings propose a mechanism by which PINK1 dysfunction renders neurons vulnerable to cell death.


Assuntos
Apoptose , Cálcio/metabolismo , Células-Tronco Fetais/enzimologia , Mitocôndrias/enzimologia , Neurônios/enzimologia , Transtornos Parkinsonianos/enzimologia , Proteínas Quinases/metabolismo , Animais , Apoptose/efeitos dos fármacos , Apoptose/efeitos da radiação , Linhagem Celular Tumoral , Células Cultivadas , Citosol/metabolismo , Metabolismo Energético , Células-Tronco Fetais/efeitos dos fármacos , Células-Tronco Fetais/patologia , Células-Tronco Fetais/efeitos da radiação , Proteínas Facilitadoras de Transporte de Glucose/metabolismo , Homeostase , Humanos , Potencial da Membrana Mitocondrial , Mesencéfalo/embriologia , Mesencéfalo/enzimologia , Camundongos , Camundongos Knockout , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/patologia , Mitocôndrias/efeitos da radiação , Proteínas de Transporte da Membrana Mitocondrial/metabolismo , Poro de Transição de Permeabilidade Mitocondrial , NADPH Oxidases/metabolismo , Neurônios/efeitos dos fármacos , Neurônios/patologia , Neurônios/efeitos da radiação , Oxirredução , Estresse Oxidativo , Transtornos Parkinsonianos/genética , Transtornos Parkinsonianos/patologia , Proteínas Quinases/deficiência , Proteínas Quinases/genética , Interferência de RNA , RNA Interferente Pequeno/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Trocador de Sódio e Cálcio/metabolismo , Fatores de Tempo , Raios Ultravioleta
17.
Cancer Cell ; 13(2): 83-5, 2008 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-18242507

RESUMO

Despite the proven benefit of antiestrogen drugs in breast cancer treatment, resistant disease ultimately develops in advanced breast cancer. In this issue of Cancer Cell, Iorns et al. find that loss of CDK10 expression promotes resistance of cells to tamoxifen and is associated with poor outcome in breast cancer patients treated with the drug. CDK10 loss increases the activity of the transcription factor ETS2 on the promoter of the RAF1 gene, elevating ERK/MAPK kinase pathway activity and relieving tamoxifen-induced G1 arrest. CDK10 is thus a potential biomarker for sensitivity in prospective clinical trials of patients treated with endocrine therapies.


Assuntos
Antineoplásicos Hormonais/uso terapêutico , Neoplasias da Mama/genética , Quinases Ciclina-Dependentes/metabolismo , Resistencia a Medicamentos Antineoplásicos/genética , Genômica , Antineoplásicos Hormonais/farmacologia , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/enzimologia , Proteínas de Ligação a DNA/metabolismo , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Estrogênios/deficiência , Humanos , Proteínas Proto-Oncogênicas c-raf/metabolismo , RNA Interferente Pequeno/metabolismo , Proteínas Repressoras/metabolismo , Tamoxifeno/farmacologia , Tamoxifeno/uso terapêutico , Fatores de Transcrição/metabolismo
19.
Angew Chem Int Ed Engl ; 55(42): 13174-13179, 2016 10 10.
Artigo em Inglês | MEDLINE | ID: mdl-27654901

RESUMO

We have developed a convenient method for the direct synthesis of peptide thioesters, versatile intermediates for peptide ligation and cyclic peptide synthesis. The technology uses a modified Boc SPPS strategy that avoids the use of anhydrous HF. Boc in situ neutralization protocols are used in combination with Merrifield hydroxymethyl resin and TFA/TMSBr cleavage. Avoiding HF extends the scope of Boc SPPS to post-translational modifications that are compatible with the milder cleavage conditions, demonstrated here with the synthesis of the phosphorylated protein CHK2. Peptide thioesters give easy, direct, access to cyclic peptides, illustrated by the synthesis of cyclorasin, a KRAS inhibitor.


Assuntos
Ésteres/química , Ésteres do Ácido Fórmico/síntese química , Peptídeos/química , Compostos de Sulfidrila/química , Ciclização , Ésteres do Ácido Fórmico/química , Estrutura Molecular
20.
N Engl J Med ; 366(10): 883-892, 2012 Mar 08.
Artigo em Inglês | MEDLINE | ID: mdl-22397650

RESUMO

BACKGROUND: Intratumor heterogeneity may foster tumor evolution and adaptation and hinder personalized-medicine strategies that depend on results from single tumor-biopsy samples. METHODS: To examine intratumor heterogeneity, we performed exome sequencing, chromosome aberration analysis, and ploidy profiling on multiple spatially separated samples obtained from primary renal carcinomas and associated metastatic sites. We characterized the consequences of intratumor heterogeneity using immunohistochemical analysis, mutation functional analysis, and profiling of messenger RNA expression. RESULTS: Phylogenetic reconstruction revealed branched evolutionary tumor growth, with 63 to 69% of all somatic mutations not detectable across every tumor region. Intratumor heterogeneity was observed for a mutation within an autoinhibitory domain of the mammalian target of rapamycin (mTOR) kinase, correlating with S6 and 4EBP phosphorylation in vivo and constitutive activation of mTOR kinase activity in vitro. Mutational intratumor heterogeneity was seen for multiple tumor-suppressor genes converging on loss of function; SETD2, PTEN, and KDM5C underwent multiple distinct and spatially separated inactivating mutations within a single tumor, suggesting convergent phenotypic evolution. Gene-expression signatures of good and poor prognosis were detected in different regions of the same tumor. Allelic composition and ploidy profiling analysis revealed extensive intratumor heterogeneity, with 26 of 30 tumor samples from four tumors harboring divergent allelic-imbalance profiles and with ploidy heterogeneity in two of four tumors. CONCLUSIONS: Intratumor heterogeneity can lead to underestimation of the tumor genomics landscape portrayed from single tumor-biopsy samples and may present major challenges to personalized-medicine and biomarker development. Intratumor heterogeneity, associated with heterogeneous protein function, may foster tumor adaptation and therapeutic failure through Darwinian selection. (Funded by the Medical Research Council and others.).


Assuntos
Carcinoma de Células Renais/genética , Evolução Molecular , Heterogeneidade Genética , Neoplasias Renais/genética , Fenótipo , Biomarcadores Tumorais , Biópsia , Carcinoma de Células Renais/patologia , Carcinoma de Células Renais/secundário , Aberrações Cromossômicas , Everolimo , Exoma , Heterogeneidade Genética/efeitos dos fármacos , Humanos , Imunossupressores/farmacologia , Rim/patologia , Neoplasias Renais/patologia , Mutação , Metástase Neoplásica/genética , Metástase Neoplásica/patologia , Filogenia , Ploidias , Polimorfismo de Nucleotídeo Único , Análise de Sequência de DNA , Sirolimo/análogos & derivados , Sirolimo/farmacologia
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