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1.
Mol Cancer Ther ; 23(4): 421-435, 2024 Apr 02.
Artigo em Inglês | MEDLINE | ID: mdl-38030380

RESUMO

IL12 is a proinflammatory cytokine, that has shown promising antitumor activity in humans by promoting the recruitment and activation of immune cells in tumors. However, the systemic administration of IL12 has been accompanied by considerable toxicity, prompting interest in researching alternatives to drive preferential IL12 bioactivity in the tumor. Here, we have generated XTX301, a tumor-activated IL12 linked to the human Fc protein via a protease cleavable linker that is pharmacologically inactivated by an IL12 receptor subunit beta 2 masking domain. In vitro characterization demonstrates multiple matrix metalloproteases, as well as human primary tumors cultured as cell suspensions, can effectively activate XTX301. Intravenous administration of a mouse surrogate mXTX301 demonstrated significant tumor growth inhibition (TGI) in inflamed and non-inflamed mouse models without causing systemic toxicities. The superiority of mXTX301 in mediating TGI compared with non-activatable control molecules and the greater percentage of active mXTX301 in tumors versus other organs further confirms activation by the tumor microenvironment-associated proteases in vivo. Pharmacodynamic characterization shows tumor selective increases in inflammation and upregulation of immune-related genes involved in IFNγ cell signaling, antigen processing, presentation, and adaptive immune response. XTX301 was tolerated following four repeat doses up to 2.0 mg/kg in a nonhuman primate study; XTX301 exposures were substantially higher than those at the minimally efficacious dose in mice. Thus, XTX301 has the potential to achieve potent antitumor activity while widening the therapeutic index of IL12 treatment and is currently being evaluated in a phase I clinical trial.


Assuntos
Interleucina-12 , Neoplasias , Humanos , Camundongos , Animais , Interleucina-12/metabolismo , Neoplasias/tratamento farmacológico , Citocinas , Transdução de Sinais , Índice Terapêutico , Microambiente Tumoral
2.
Acad Emerg Med ; 31(1): 71-85, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37813813

RESUMO

OBJECTIVE: The objective was to identify the highest quality global emergency medicine (GEM) research published in 2022. The top articles are compiled in a comprehensive list of all the year's GEM articles and narrative summaries are performed on those included. METHODS: A systematic PubMed search was conducted to identify all GEM articles published in 2022 and included a manual supplemental screen of 11 organizational websites for gray literature (GRAY). A team of trained reviewers and editors screened all identified titles and abstracts, based on three case definition categories: disaster and humanitarian response (DHR), emergency care in resource-limited settings (ECRLS), and emergency medicine development (EMD). Articles meeting these definitions were independently scored by two reviewers using rubrics for original research (OR), review (RE) articles, and GRAY. Articles that scored in the top 5% from each category as well as the overall top 5% of articles were included for narrative summary. RESULTS: The 2022 search identified 58,510 articles in the main review, of which 524 articles screened in for scoring, respectively, 30% and 18% increases from last year. After duplicates were removed, 36 articles were included for narrative summary. The GRAY search identified 7755 articles, of which 33 were scored and one was included for narrative summary. ECRLS remained the largest category (27; 73%), followed by DHR (7; 19%) and EMD (3; 8%). OR articles remained more common than RE articles (64% vs. 36%). CONCLUSIONS: The waning of the COVID-19 pandemic has not affected the continued growth in GEM literature. Articles related to prehospital care, mental health and resilience among patients and health care workers, streamlining pediatric infectious disease care, and disaster preparedness were featured in this year's review. The continued lack of EMD studies despite the global growth of GEM highlights a need for more scholarly dissemination of best practices.


Assuntos
Desastres , Serviços Médicos de Emergência , Medicina de Emergência , Criança , Humanos , Pandemias , Saúde Global
3.
Nat Commun ; 14(1): 7337, 2023 11 13.
Artigo em Inglês | MEDLINE | ID: mdl-37957172

RESUMO

The PIWI-interacting RNA (piRNA) pathway prevents endogenous genomic parasites, i.e. transposable elements, from damaging the genetic material of animal gonadal cells. Specific regions in the genome, called piRNA clusters, are thought to define each species' piRNA repertoire and therefore its capacity to recognize and silence specific transposon families. The unistrand cluster flamenco (flam) is essential in the somatic compartment of the Drosophila ovary to restrict Gypsy-family transposons from infecting the neighbouring germ cells. Disruption of flam results in transposon de-repression and sterility, yet it remains unknown whether this silencing mechanism is present more widely. Here, we systematically characterise 119 Drosophila species and identify five additional flam-like clusters separated by up to 45 million years of evolution. Small RNA-sequencing validated these as bona-fide unistrand piRNA clusters expressed in somatic cells of the ovary, where they selectively target transposons of the Gypsy family. Together, our study provides compelling evidence of a widely conserved transposon silencing mechanism that co-evolved with virus-like Gypsy-family transposons.


Assuntos
Proteínas de Drosophila , Retrovirus Endógenos , Humanos , Animais , Feminino , Drosophila/genética , Drosophila/metabolismo , RNA de Interação com Piwi , Retrovirus Endógenos/genética , Retrovirus Endógenos/metabolismo , Proteínas de Drosophila/genética , Proteínas de Drosophila/metabolismo , RNA Interferente Pequeno/genética , RNA Interferente Pequeno/metabolismo , Proteínas Argonautas/genética , Proteínas Argonautas/metabolismo , Elementos de DNA Transponíveis/genética , Drosophila melanogaster/genética , Drosophila melanogaster/metabolismo
4.
Sci Rep ; 13(1): 4871, 2023 03 24.
Artigo em Inglês | MEDLINE | ID: mdl-36964158

RESUMO

A new statistical analysis of large neuronal avalanches observed in mouse and rat brain tissues reveals a substantial degree of recurrent activity and cyclic patterns of activation not seen in smaller avalanches. To explain these observations, we adapted a model of structural weakening in materials. In this model, dynamical weakening of neuron firing thresholds closely replicates experimental avalanche size distributions, firing number distributions, and patterns of cyclic activity. This agreement between model and data suggests that a mechanism like dynamical weakening plays a key role in recurrent activity found in large neuronal avalanches. We expect these results to illuminate the causes and dynamics of large avalanches, like those seen in seizures.


Assuntos
Avalanche , Modelos Neurológicos , Ratos , Camundongos , Animais , Potenciais de Ação/fisiologia , Rede Nervosa/fisiologia , Neurônios/fisiologia
5.
J Immunother Cancer ; 11(12)2023 12 12.
Artigo em Inglês | MEDLINE | ID: mdl-38164757

RESUMO

INTRODUCTION: The clinical benefit of the anti-CTLA-4 monoclonal antibody (mAb) ipilimumab has been well established but limited by immune-related adverse events, especially when ipilimumab is used in combination with anti-PD-(L)1 mAb therapy. To overcome these limitations, we have developed XTX101, a tumor-activated, Fc-enhanced anti-CTLA-4 mAb. METHODS: XTX101 consists of an anti-human CTLA-4 mAb covalently linked to masking peptides that block the complementarity-determining regions, thereby minimizing the mAb binding to CTLA-4. The masking peptides are designed to be released by proteases that are typically dysregulated within the tumor microenvironment (TME), resulting in activation of XTX101 intratumorally. Mutations within the Fc region of XTX101 were included to enhance affinity for FcγRIII, which is expected to enhance potency through antibody-dependent cellular cytotoxicity. RESULTS: Biophysical, biochemical, and cell-based assays demonstrate that the function of XTX101 depends on proteolytic activation. In human CTLA-4 transgenic mice, XTX101 monotherapy demonstrated significant tumor growth inhibition (TGI) including complete responses, increased intratumoral CD8+T cells, and regulatory T cell depletion within the TME while maintaining minimal pharmacodynamic effects in the periphery. XTX101 in combination with anti-PD-1 mAb treatment resulted in significant TGI and was well tolerated in mice. XTX101 was activated in primary human tumors across a range of tumor types including melanoma, renal cell carcinoma, colon cancer and lung cancer in an ex vivo assay system. CONCLUSIONS: These data demonstrate that XTX101 retains the full potency of an Fc-enhanced CTLA-4 antagonist within the TME while minimizing the activity in non-tumor tissue, supporting the further evaluation of XTX101 in clinical studies.


Assuntos
Antineoplásicos , Melanoma , Humanos , Camundongos , Animais , Antígeno CTLA-4 , Ipilimumab/uso terapêutico , Antineoplásicos/uso terapêutico , Anticorpos Monoclonais/farmacologia , Anticorpos Monoclonais/uso terapêutico , Melanoma/tratamento farmacológico , Modelos Animais de Doenças , Camundongos Transgênicos , Peptídeos/uso terapêutico , Microambiente Tumoral
6.
Proc Natl Acad Sci U S A ; 119(43): e2209563119, 2022 10 25.
Artigo em Inglês | MEDLINE | ID: mdl-36256815

RESUMO

The successful application of antibody-based therapeutics in either primary or metastatic cancer depends upon the selection of rare cell surface epitopes that distinguish cancer cells from surrounding normal epithelial cells. By contrast, as circulating tumor cells (CTCs) transit through the bloodstream, they are surrounded by hematopoietic cells with dramatically distinct cell surface proteins, greatly expanding the number of targetable epitopes. Here, we show that an antibody (23C6) against cadherin proteins effectively suppresses blood-borne metastasis in mouse isogenic and xenograft models of triple negative breast and pancreatic cancers. The 23C6 antibody is remarkable in that it recognizes both the epithelial E-cadherin (CDH1) and mesenchymal OB-cadherin (CDH11), thus overcoming considerable heterogeneity across tumor cells. Despite its efficacy against single cells in circulation, the antibody does not suppress primary tumor formation, nor does it elicit detectable toxicity in normal epithelial organs, where cadherins may be engaged within intercellular junctions and hence inaccessible for antibody binding. Antibody-mediated suppression of metastasis is comparable in matched immunocompetent and immunodeficient mouse models. Together, these studies raise the possibility of antibody targeting CTCs within the vasculature, thereby suppressing blood-borne metastasis.


Assuntos
Neoplasias da Mama , Células Neoplásicas Circulantes , Neoplasias Pancreáticas , Humanos , Animais , Camundongos , Feminino , Transição Epitelial-Mesenquimal , Linhagem Celular Tumoral , Caderinas/metabolismo , Células Neoplásicas Circulantes/patologia , Processos Neoplásicos , Neoplasias Pancreáticas/tratamento farmacológico , Camundongos Nus , Camundongos SCID , Epitopos , Neoplasias da Mama/tratamento farmacológico , Metástase Neoplásica , Neoplasias Pancreáticas
7.
Acad Emerg Med ; 29(10): 1264-1274, 2022 10.
Artigo em Inglês | MEDLINE | ID: mdl-35913419

RESUMO

OBJECTIVE: The objective was to identify the most important and impactful peer-reviewed global emergency medicine (GEM) articles published in 2021. The top articles are summarized in brief narratives and accompanied by a comprehensive list of all identified articles that address the topic during the year to serve as a reference for clinicians, researchers, and policy makers. METHODS: A systematic PubMed search was carried out to identify all GEM articles published in 2021. Title and abstract screening was performed by trained reviewers and editors to identify articles in one of three categories based on predefined criteria: disaster and humanitarian response (DHR), emergency care in resource-limited settings (ECRLS), and emergency medicine development (EMD). Included articles were each scored by two reviewers using established rubrics for original (OR) and review (RE) articles. The top 5% of articles overall and the top 5% of articles from each category (DHR, ECRLS, EMD, OR, and RE) were included for narrative summary. RESULTS: The 2021 search identified 44,839 articles, of which 444 articles screened in for scoring, 25% and 22% increases from 2020, respectively. After removal of duplicates, 23 articles were included for narrative summary. ECRLS constituted the largest category (n = 16, 70%), followed by EMD (n = 4, 17%) and DHR (n = 3, 13%). The majority of top articles were OR (n = 14, 61%) compared to RE (n = 9, 39%). CONCLUSIONS: The GEM peer-reviewed literature continued to grow at a fast rate in 2021, reflecting the continued expansion and maturation of this subspecialty of emergency medicine. Few high-quality articles focused on DHR and EMD, suggesting a need for further efforts in those fields. Future efforts should focus on improving the diversity of GEM research and equitable representation.


Assuntos
Desastres , Serviços Médicos de Emergência , Medicina de Emergência , Saúde Global , Humanos , Revisão por Pares
8.
Blood Cancer Discov ; 3(4): 298-315, 2022 07 06.
Artigo em Inglês | MEDLINE | ID: mdl-35405004

RESUMO

Approximately 20% of patients with myeloproliferative neoplasms (MPN) harbor mutations in the gene calreticulin (CALR), with 80% of those mutations classified as either type I or type II. While type II CALR-mutant proteins retain many of the Ca2+ binding sites present in the wild-type protein, type I CALR-mutant proteins lose these residues. The functional consequences of this differential loss of Ca2+ binding sites remain unexplored. Here, we show that the loss of Ca2+ binding residues in the type I mutant CALR protein directly impairs its Ca2+ binding ability, which in turn leads to depleted endoplasmic reticulum (ER) Ca2+ and subsequent activation of the IRE1α/XBP1 pathway of the unfolded protein response. Genetic or pharmacologic inhibition of IRE1α/XBP1 signaling induces cell death in type I mutant but not type II mutant or wild-type CALR-expressing cells, and abrogates type I mutant CALR-driven MPN disease progression in vivo. SIGNIFICANCE: Current targeted therapies for CALR-mutated MPNs are not curative and fail to differentiate between type I- versus type II-driven disease. To improve treatment strategies, it is critical to identify CALR mutation type-specific vulnerabilities. Here we show that IRE1α/XBP1 represents a unique, targetable dependency specific to type I CALR-mutated MPNs. This article is highlighted in the In This Issue feature, p. 265.


Assuntos
Calreticulina , Transtornos Mieloproliferativos , Neoplasias , Resposta a Proteínas não Dobradas , Cálcio/metabolismo , Calreticulina/genética , Endorribonucleases/genética , Humanos , Proteínas Mutantes/química , Mutação , Transtornos Mieloproliferativos/genética , Proteínas Serina-Treonina Quinases/genética , Proteína 1 de Ligação a X-Box/genética
10.
Acad Emerg Med ; 28(11): 1328-1340, 2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-34310782

RESUMO

OBJECTIVE: The objective was to identify, screen, highlight, review, and summarize some of the most rigorously conducted and impactful original research (OR) and review articles (RE) in global emergency medicine (EM) published in 2020 in the peer-reviewed and gray literature. METHODS: A broad systematic search of peer-reviewed publications related to global EM indexed on PubMed and in the gray literature was conducted. The titles and abstracts of the articles on this list were screened by members of the Global Emergency Medicine Literature Review (GEMLR) Group to identify those that met our criteria of OR or RE in the domains of disaster and humanitarian response (DHR), emergency care in resource-limited settings (ECRLS), and EM development. Those articles that met these screening criteria were then scored using one of three scoring templates appropriate to the article type. Those articles that scored in the top 5% then underwent in-depth narrative summarization. RESULTS: The 2020 GEMLR search initially identified 35,970 articles, more than 50% more than last year's search. From these, 364 were scored based on their full text. Nearly three-fourths of the scored articles constituted OR, of which nearly three-fourths employed quantitative research methods. Nearly 10% of the articles identified this year were directly related to COVID-19. Research involving ECRLS again constituted most of the articles in this year's review, accounting for more than 60% of the literature scored. A total of 20 articles underwent in-depth narrative critiques. CONCLUSIONS: The number of studies relevant to global EM identified by our search was very similar to that of last year. Revisions to our methodology to identify a broader range of research were successful in identifying more qualitative research and studies related to DHR. The number of COVID-19-related articles is likely to continue to increase in subsequent years.


Assuntos
COVID-19 , Serviços Médicos de Emergência , Medicina de Emergência , Saúde Global , Humanos , SARS-CoV-2
11.
BMC Infect Dis ; 21(1): 580, 2021 Jun 16.
Artigo em Inglês | MEDLINE | ID: mdl-34134647

RESUMO

BACKGROUND: COVID-19 has resulted in significant morbidity and mortality worldwide. Lateral flow assays can detect anti-Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) antibodies to monitor transmission. However, standardized evaluation of their accuracy and tools to aid in interpreting results are needed. METHODS: We evaluated 20 IgG and IgM assays selected from available tests in April 2020. We evaluated the assays' performance using 56 pre-pandemic negative and 56 SARS-CoV-2-positive plasma samples, collected 10-40 days after symptom onset, confirmed by a molecular test and analyzed by an ultra-sensitive immunoassay. Finally, we developed a user-friendly web app to extrapolate the positive predictive values based on their accuracy and local prevalence. RESULTS: Combined IgG + IgM sensitivities ranged from 33.9 to 94.6%, while combined specificities ranged from 92.6 to 100%. The highest sensitivities were detected in Lumiquick for IgG (98.2%), BioHit for both IgM (96.4%), and combined IgG + IgM sensitivity (94.6%). Furthermore, 11 LFAs and 8 LFAs showed perfect specificity for IgG and IgM, respectively, with 15 LFAs showing perfect combined IgG + IgM specificity. Lumiquick had the lowest estimated limit-of-detection (LOD) (0.1 µg/mL), followed by a similar LOD of 1.5 µg/mL for CareHealth, Cellex, KHB, and Vivachek. CONCLUSION: We provide a public resource of the accuracy of select lateral flow assays with potential for home testing. The cost-effectiveness, scalable manufacturing process, and suitability for self-testing makes LFAs an attractive option for monitoring disease prevalence and assessing vaccine responsiveness. Our web tool provides an easy-to-use interface to demonstrate the impact of prevalence and test accuracy on the positive predictive values.


Assuntos
Anticorpos Antivirais/sangue , Teste Sorológico para COVID-19/métodos , COVID-19/diagnóstico , Imunoglobulina G/sangue , Imunoglobulina M/sangue , SARS-CoV-2/imunologia , Adulto , Idoso , COVID-19/sangue , Feminino , Humanos , Limite de Detecção , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Prevalência , Sensibilidade e Especificidade , Design Centrado no Usuário , Interface Usuário-Computador
12.
J Med Chem ; 64(7): 3911-3939, 2021 04 08.
Artigo em Inglês | MEDLINE | ID: mdl-33755451

RESUMO

Protein arginine methyltransferase 5 (PRMT5) is a type II arginine methyltransferase that catalyzes the post-translational symmetric dimethylation of protein substrates. PRMT5 plays a critical role in regulating biological processes including transcription, cell cycle progression, RNA splicing, and DNA repair. As such, dysregulation of PRMT5 activity is implicated in the development and progression of multiple cancers and is a target of growing clinical interest. Described herein are the structure-based drug designs, robust synthetic efforts, and lead optimization strategies toward the identification of two novel 5,5-fused bicyclic nucleoside-derived classes of potent and efficacious PRMT5 inhibitors. Utilization of compound docking and strain energy calculations inspired novel designs, and the development of flexible synthetic approaches enabled access to complex chemotypes with five contiguous stereocenters. Additional efforts in balancing bioavailability, solubility, potency, and CYP3A4 inhibition led to the identification of diverse lead compounds with favorable profiles, promising in vivo activity, and low human dose projections.


Assuntos
Aminoquinolinas/uso terapêutico , Antineoplásicos/uso terapêutico , Inibidores Enzimáticos/uso terapêutico , Neoplasias/tratamento farmacológico , Nucleosídeos/uso terapêutico , Proteína-Arginina N-Metiltransferases/antagonistas & inibidores , Aminoquinolinas/síntese química , Aminoquinolinas/metabolismo , Animais , Antineoplásicos/síntese química , Antineoplásicos/metabolismo , Proliferação de Células/efeitos dos fármacos , Desenho de Fármacos , Inibidores Enzimáticos/síntese química , Inibidores Enzimáticos/metabolismo , Feminino , Humanos , Camundongos SCID , Simulação de Acoplamento Molecular , Estrutura Molecular , Nucleosídeos/síntese química , Nucleosídeos/metabolismo , Ligação Proteica , Proteína-Arginina N-Metiltransferases/metabolismo , Relação Estrutura-Atividade
13.
Am J Ophthalmol ; 229: 18-25, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-33626361

RESUMO

PURPOSE: To assess the incidence of unplanned return to the operating room (ROR) at ≤45 days or ≥46 days after primary retinal detachment (RD) surgery and correlate ROR with preoperative risk factors and visual outcomes. DESIGN: Retrospective cohort study. METHODS: This was a retrospective review of patients with primary RD surgery to assess for unplanned ROR between January 1, 2012 and June 30, 2014, with follow-up of 90 days to 8 years (mean, 1.5 years). We assessed 268 patients receiving 270 primary rhegmatogenous RD surgeries between January 1, 2012 and June 30, 2014 in an academic tertiary referral center. RESULTS: Of the 270 RD surgeries, 82 were complicated (history of proliferative vitreoretinopathy or trauma-related RDs at presentation) and 188 were uncomplicated (RD unrelated to trauma or proliferative vitreoretinopathy at presentation). The ROR rate for all surgeries was 12.2% (33/270) over the follow-up period, with 51.5% (17/33) having reoperations within 45 days. The complicated detachment group had a ROR rate of 14.6% (12/82) over the follow-up period, and 50% of those (6/12) had reoperations within 45 days. The uncomplicated detachment group had a ROR rate of 11.2% (21/188) over the follow-up period. Of those, 52.4% (11/21) had reoperations within 45 days. CONCLUSIONS: Given that only 51.5% of all RORs occurred within 45 days, a 45-day ROR surgical quality metric that has been previously used may be of limited value for RD surgery. Factors such as age at presentation, number of retinal breaks, number of detached clock hours, use of silicone oil tamponade for pars plana vitrectomy, history of choroidal detachment, high myopia, ocular trauma, and open globe were associated with increasing risk of ROR. Implementing risk-adjusted metrics may provide a more accurate and useful quality improvement metric for evaluating quality of surgical care in vitreoretinal surgery. Am J Ophthalmol 2021;221:•••-•••. © 2021 Elsevier Inc. All rights reserved.


Assuntos
Descolamento Retiniano , Humanos , Salas Cirúrgicas , Descolamento Retiniano/cirurgia , Estudos Retrospectivos , Fatores de Risco , Óleos de Silicone , Resultado do Tratamento , Vitrectomia
14.
Nat Commun ; 11(1): 3303, 2020 07 03.
Artigo em Inglês | MEDLINE | ID: mdl-32620742

RESUMO

Pancreatic ductal adenocarcinoma (PDAC) lethality is due to metastatic dissemination. Characterization of rare, heterogeneous circulating tumor cells (CTCs) can provide insight into metastasis and guide development of novel therapies. Using the CTC-iChip to purify CTCs from PDAC patients for RNA-seq characterization, we identify three major correlated gene sets, with stemness genes LIN28B/KLF4, WNT5A, and LGALS3 enriched in each correlated gene set; only LIN28B CTC expression was prognostic. CRISPR knockout of LIN28B-an oncofetal RNA-binding protein exerting diverse effects via negative regulation of let-7 miRNAs and other RNA targets-in cell and animal models confers a less aggressive/metastatic phenotype. This correlates with de-repression of let-7 miRNAs and is mimicked by silencing of downstream let-7 target HMGA2 or chemical inhibition of LIN28B/let-7 binding. Molecular characterization of CTCs provides a unique opportunity to correlated gene set metastatic profiles, identify drivers of dissemination, and develop therapies targeting the "seeds" of metastasis.


Assuntos
Carcinoma Ductal Pancreático/genética , Proteína HMGA2/genética , MicroRNAs/genética , Células Neoplásicas Circulantes/metabolismo , Neoplasias Pancreáticas/genética , Proteínas de Ligação a RNA/genética , Adulto , Idoso , Animais , Carcinoma Ductal Pancreático/tratamento farmacológico , Carcinoma Ductal Pancreático/metabolismo , Linhagem Celular Tumoral , Movimento Celular/genética , Feminino , Regulação Neoplásica da Expressão Gênica , Proteína HMGA2/metabolismo , Humanos , Estimativa de Kaplan-Meier , Fator 4 Semelhante a Kruppel , Masculino , Camundongos Endogâmicos NOD , Camundongos Knockout , Camundongos SCID , Pessoa de Meia-Idade , Metástase Neoplásica , Neoplasias Pancreáticas/tratamento farmacológico , Neoplasias Pancreáticas/metabolismo , Proteínas de Ligação a RNA/metabolismo
15.
Genome Biol ; 21(1): 33, 2020 02 10.
Artigo em Inglês | MEDLINE | ID: mdl-32039742

RESUMO

BACKGROUND: Quiescence (G0) is a transient, cell cycle-arrested state. By entering G0, cancer cells survive unfavorable conditions such as chemotherapy and cause relapse. While G0 cells have been studied at the transcriptome level, how post-transcriptional regulation contributes to their chemoresistance remains unknown. RESULTS: We induce chemoresistant and G0 leukemic cells by serum starvation or chemotherapy treatment. To study post-transcriptional regulation in G0 leukemic cells, we systematically analyzed their transcriptome, translatome, and proteome. We find that our resistant G0 cells recapitulate gene expression profiles of in vivo chemoresistant leukemic and G0 models. In G0 cells, canonical translation initiation is inhibited; yet we find that inflammatory genes are highly translated, indicating alternative post-transcriptional regulation. Importantly, AU-rich elements (AREs) are significantly enriched in the upregulated G0 translatome and transcriptome. Mechanistically, we find the stress-responsive p38 MAPK-MK2 signaling pathway stabilizes ARE mRNAs by phosphorylation and inactivation of mRNA decay factor, Tristetraprolin (TTP) in G0. This permits expression of ARE mRNAs that promote chemoresistance. Conversely, inhibition of TTP phosphorylation by p38 MAPK inhibitors and non-phosphorylatable TTP mutant decreases ARE-bearing TNFα and DUSP1 mRNAs and sensitizes leukemic cells to chemotherapy. Furthermore, co-inhibiting p38 MAPK and TNFα prior to or along with chemotherapy substantially reduces chemoresistance in primary leukemic cells ex vivo and in vivo. CONCLUSIONS: These studies uncover post-transcriptional regulation underlying chemoresistance in leukemia. Our data reveal the p38 MAPK-MK2-TTP axis as a key regulator of expression of ARE-bearing mRNAs that promote chemoresistance. By disrupting this pathway, we develop an effective combination therapy against chemosurvival.


Assuntos
Elementos Ricos em Adenilato e Uridilato , Resistencia a Medicamentos Antineoplásicos , Processamento Pós-Transcricional do RNA , Tristetraprolina/metabolismo , Animais , Ciclo Celular , Células Cultivadas , Fosfatase 1 de Especificidade Dupla/genética , Fosfatase 1 de Especificidade Dupla/metabolismo , Células Hep G2 , Humanos , Peptídeos e Proteínas de Sinalização Intracelular/genética , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Células K562 , Células MCF-7 , Camundongos , Camundongos Endogâmicos C57BL , Proteínas Serina-Treonina Quinases/genética , Proteínas Serina-Treonina Quinases/metabolismo , Proteoma/genética , Proteoma/metabolismo , Células THP-1 , Transcriptoma , Tristetraprolina/genética , Fator de Necrose Tumoral alfa/metabolismo , Proteínas Quinases p38 Ativadas por Mitógeno/genética , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismo
16.
Science ; 367(6485): 1468-1473, 2020 03 27.
Artigo em Inglês | MEDLINE | ID: mdl-32029688

RESUMO

Circulating tumor cells (CTCs) are shed into the bloodstream from primary tumors, but only a small subset of these cells generates metastases. We conducted an in vivo genome-wide CRISPR activation screen in CTCs from breast cancer patients to identify genes that promote distant metastasis in mice. Genes coding for ribosomal proteins and regulators of translation were enriched in this screen. Overexpression of RPL15, which encodes a component of the large ribosomal subunit, increased metastatic growth in multiple organs and selectively enhanced translation of other ribosomal proteins and cell cycle regulators. RNA sequencing of freshly isolated CTCs from breast cancer patients revealed a subset with strong ribosome and protein synthesis signatures; these CTCs expressed proliferation and epithelial markers and correlated with poor clinical outcome. Therapies targeting this aggressive subset of CTCs may merit exploration as potential suppressors of metastatic progression.


Assuntos
Neoplasias da Mama/patologia , Metástase Neoplásica , Células Neoplásicas Circulantes/patologia , Proteínas Ribossômicas/genética , Animais , Neoplasias da Mama/genética , Sistemas CRISPR-Cas , Linhagem Celular Tumoral , Feminino , Regulação Neoplásica da Expressão Gênica , Humanos , Camundongos , Transplante de Neoplasias , Análise de Sequência de RNA
17.
Nat Commun ; 10(1): 5759, 2019 12 17.
Artigo em Inglês | MEDLINE | ID: mdl-31848333

RESUMO

PRDM9 is a PR domain containing protein which trimethylates histone 3 on lysine 4 and 36. Its normal expression is restricted to germ cells and attenuation of its activity results in altered meiotic gene transcription, impairment of double-stranded breaks and pairing between homologous chromosomes. There is growing evidence for a role of aberrant expression of PRDM9 in oncogenesis and genome instability. Here we report the discovery of MRK-740, a potent (IC50: 80 ± 16 nM), selective and cell-active PRDM9 inhibitor (Chemical Probe). MRK-740 binds in the substrate-binding pocket, with unusually extensive interactions with the cofactor S-adenosylmethionine (SAM), conferring SAM-dependent substrate-competitive inhibition. In cells, MRK-740 specifically and directly inhibits H3K4 methylation at endogenous PRDM9 target loci, whereas the closely related inactive control compound, MRK-740-NC, does not. The discovery of MRK-740 as a chemical probe for the PRDM subfamily of methyltransferases highlights the potential for exploiting SAM in targeting SAM-dependent methyltransferases.


Assuntos
Descoberta de Drogas/métodos , Inibidores Enzimáticos/farmacologia , Histona-Lisina N-Metiltransferase/antagonistas & inibidores , Sondas Moleculares/farmacologia , Cristalografia por Raios X , Metilação de DNA/efeitos dos fármacos , Inibidores Enzimáticos/química , Células HEK293 , Histona-Lisina N-Metiltransferase/metabolismo , Histona-Lisina N-Metiltransferase/ultraestrutura , Histonas/metabolismo , Humanos , Concentração Inibidora 50 , Simulação de Dinâmica Molecular , Sondas Moleculares/química , Domínios Proteicos , S-Adenosilmetionina/metabolismo
18.
J Cell Mol Med ; 23(10): 7063-7077, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31449347

RESUMO

This study reports the establishment of a bone marrow mononuclear cell (BMMC) 3D culture model and the application of this model to define sensitivity and resistance biomarkers of acute myeloid leukaemia (AML) patient bone marrow samples in response to Cytarabine (Ara-C) treatment. By mimicking physiological bone marrow microenvironment, the growth conditions were optimized by using frozen BMMCs derived from healthy donors. Healthy BMMCs are capable of differentiating into major hematopoietic lineages and various types of stromal cells in this platform. Cryopreserved BMMC samples from 49 AML patients were characterized for ex vivo growth and sensitivity to Ara-C. RNA sequencing was performed for 3D and 2D cultures to determine differential gene expression patterns. Specific genetic mutations and/or gene expression signatures associated with the ability of the ex vivo expansion and response to Ara-C were elucidated by whole-exome and RNA sequencing. Data analysis identified unique gene expression signatures and novel genetic mutations associated with sensitivity to Ara-C treatment of proliferating AML specimens and can be used as predictive therapeutic biomarkers to determine the optimal treatment regimens. Furthermore, these data demonstrate the translational value of this ex vivo platform which should be widely applicable to evaluate other therapies in AML.


Assuntos
Citarabina/uso terapêutico , Leucemia Mieloide Aguda/tratamento farmacológico , Leucemia Mieloide Aguda/genética , Modelos Biológicos , Adulto , Idoso , Idoso de 80 Anos ou mais , Células da Medula Óssea/metabolismo , Linhagem Celular Tumoral , Citarabina/farmacologia , Feminino , Regulação Leucêmica da Expressão Gênica/efeitos dos fármacos , Humanos , Concentração Inibidora 50 , Masculino , Pessoa de Meia-Idade , Mutação/genética , Proteínas de Fusão Oncogênica/genética , Proteínas de Fusão Oncogênica/metabolismo , Resultado do Tratamento
19.
J Spec Oper Med ; 19(1): 66-69, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30859530

RESUMO

Current prolonged field care (PFC) training routinely occurs in simulated physical locations that force providers to continue care until evacuation to definitive care, as based on the staged Ruck-Truck-House-Plane model. As PFC-capable teams move further forward into austere environments in support of the fight, they are in physical locations that do not fit this staged model and may require teams to execute their own casualty evacuation through rough terrain. The physical constraints that come specifically with austere, mountainous terrain can challenge PFC providers to initiate resuscitative interventions and challenge their ability to sustain these interventions during lengthy, dismounted movement over unimproved terrain. In this brief report, we describe our experience with a novel training course designed for PFC-capable medical teams to integrate their level of advanced resuscitative care within a mountainous, rough terrain evacuation-training program. Our goals were to identify training gaps for Special Operations Forces medical units tasked to operate in a cold-weather, mountain environment with limited evacuation resources and the challenges related to maintaining PFC interventions during dismounted casualty movement.


Assuntos
Cuidados Críticos , Medicina Militar/educação , Montanhismo , Guerra , Medicina Selvagem/educação , Currículo , Humanos , Ressuscitação
20.
Semin Ophthalmol ; 33(6): 804-807, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30067427

RESUMO

PURPOSE: Retrospective cohort study to identify clinical characteristics associated with poor visual acuity in central serous chorioretinopathy (CSC). MATERIALS AND METHODS: Charts of patients in a tertiary referral clinic diagnosed with CSC over a 13-year period were reviewed. Multivariate logistic regression analyses were performed to assess the relationship between several clinical characteristics and final visual acuity. RESULTS: Of 353 subjects with CSC, 258 had a minimum of 2 clinical assessments and adequate follow-up. Multivariate analysis showed that the followings were significantly associated with worse final visual acuity: older age at diagnosis, history of photodynamic therapy, choroidal neovascularization (CNV), hypertension, and either prostate cancer or benign prostatic hypertrophy. Diabetes mellitus was associated with better final visual acuity. In a subgroup analysis of 150 subjects with at least 1 year of follow-up, CNV, hypertension, and gastroesophageal reflux disease were significantly associated with worsening of visual acuity over the study period. Use of a psychiatric medication at presentation was protective. CONCLUSION: Poor visual outcomes in CSC are associated with older age at diagnosis, CNV, hypertension, and history of prostate disease. Several clinical characteristics that have been identified as risk factors for developing CSC also appear to be associated with worse visual outcomes.


Assuntos
Coriorretinopatia Serosa Central/diagnóstico , Corioide/patologia , Técnicas de Diagnóstico Oftalmológico , Retina/patologia , Acuidade Visual/fisiologia , Coriorretinopatia Serosa Central/fisiopatologia , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Prognóstico , Estudos Retrospectivos , Fatores de Tempo
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