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1.
Mol Cell ; 81(20): 4191-4208.e8, 2021 Oct 21.
Artigo em Inglês | MEDLINE | ID: mdl-34686314

RESUMO

To survive, mammalian cells must adapt to environmental challenges. While the cellular response to mild stress has been widely studied, how cells respond to severe stress remains unclear. We show here that under severe hyperosmotic stress, cells enter a transient hibernation-like state in anticipation of recovery. We demonstrate this adaptive pausing response (APR) is a coordinated cellular response that limits ATP supply and consumption through mitochondrial fragmentation and widespread pausing of mRNA translation. This pausing is accomplished by ribosome stalling at translation initiation codons, which keeps mRNAs poised to resume translation upon recovery. We further show that recovery from severe stress involves ISR (integrated stress response) signaling that permits cell cycle progression, resumption of growth, and reversal of mitochondria fragmentation. Our findings indicate that cells can respond to severe stress via a hibernation-like mechanism that preserves vital elements of cellular function under harsh environmental conditions.

2.
Nat Commun ; 12(1): 5053, 2021 08 20.
Artigo em Inglês | MEDLINE | ID: mdl-34417459

RESUMO

Previous studies have suggested that PTEN loss is associated with p110ß signaling dependency, leading to the clinical development of p110ß-selective inhibitors. Here we use a panel pre-clinical models to reveal that PI3K isoform dependency is not governed by loss of PTEN and is impacted by feedback inhibition and concurrent PIK3CA/PIK3CB alterations. Furthermore, while pan-PI3K inhibition in PTEN-deficient tumors is efficacious, upregulation of Insulin Like Growth Factor 1 Receptor (IGF1R) promotes resistance. Importantly, we show that this resistance can be overcome through targeting AKT and we find that AKT inhibitors are superior to pan-PI3K inhibition in the context of PTEN loss. However, in the presence of wild-type PTEN and PIK3CA-activating mutations, p110α-dependent signaling is dominant and selectively inhibiting p110α is therapeutically superior to AKT inhibition. These discoveries reveal a more nuanced understanding of PI3K isoform dependency and unveil novel strategies to selectively target PI3K signaling nodes in a context-specific manner.


Assuntos
Fosfatidilinositol 3-Quinases/metabolismo , Neoplasias da Próstata/tratamento farmacológico , Neoplasias da Próstata/enzimologia , Transdução de Sinais , Animais , Linhagem Celular Tumoral , Retroalimentação Fisiológica , Humanos , Isoenzimas/metabolismo , Masculino , Camundongos , Modelos Biológicos , Organoides/efeitos dos fármacos , Organoides/metabolismo , PTEN Fosfo-Hidrolase/deficiência , PTEN Fosfo-Hidrolase/metabolismo , Fosforilação/efeitos dos fármacos , Inibidores de Proteínas Quinases/farmacologia , Receptor IGF Tipo 1/metabolismo , Regulação para Cima/efeitos dos fármacos
3.
Nat Commun ; 12(1): 4217, 2021 07 09.
Artigo em Inglês | MEDLINE | ID: mdl-34244513

RESUMO

The functional consequences of genetic variants within 5' untranslated regions (UTRs) on a genome-wide scale are poorly understood in disease. Here we develop a high-throughput multi-layer functional genomics method called PLUMAGE (Pooled full-length UTR Multiplex Assay on Gene Expression) to quantify the molecular consequences of somatic 5' UTR mutations in human prostate cancer. We show that 5' UTR mutations can control transcript levels and mRNA translation rates through the creation of DNA binding elements or RNA-based cis-regulatory motifs. We discover that point mutations can simultaneously impact transcript and translation levels of the same gene. We provide evidence that functional 5' UTR mutations in the MAP kinase signaling pathway can upregulate pathway-specific gene expression and are associated with clinical outcomes. Our study reveals the diverse mechanisms by which the mutational landscape of 5' UTRs can co-opt gene expression and demonstrates that single nucleotide alterations within 5' UTRs are functional in cancer.


Assuntos
Regiões 5' não Traduzidas/genética , Análise Mutacional de DNA/métodos , Regulação Neoplásica da Expressão Gênica , Genômica/métodos , Neoplasias da Próstata/genética , Linhagem Celular Tumoral , Células HEK293 , Ensaios de Triagem em Larga Escala , Humanos , Masculino , Mutação Puntual , Próstata/patologia , Neoplasias da Próstata/patologia , Biossíntese de Proteínas/genética , RNA-Seq
4.
JCI Insight ; 6(11)2021 Jun 08.
Artigo em Inglês | MEDLINE | ID: mdl-34032633

RESUMO

Using genetically engineered mouse models, this work demonstrates that protein synthesis is essential for efficient urothelial cancer formation and growth but dispensable for bladder homeostasis. Through a candidate gene analysis for translation regulators implicated in this dependency, we discovered that phosphorylation of the translation initiation factor eIF4E at serine 209 is increased in both murine and human bladder cancer, and this phosphorylation corresponds with an increase in de novo protein synthesis. Employing an eIF4E serine 209 to alanine knock-in mutant mouse model, we show that this single posttranslational modification is critical for bladder cancer initiation and progression, despite having no impact on normal bladder tissue maintenance. Using murine and human models of advanced bladder cancer, we demonstrate that only tumors with high levels of eIF4E phosphorylation are therapeutically vulnerable to eFT508, the first clinical-grade inhibitor of MNK1 and MNK2, the upstream kinases of eIF4E. Our results show that phospho-eIF4E plays an important role in bladder cancer pathogenesis, and targeting its upstream kinases could be an effective therapeutic option for bladder cancer patients with high levels of eIF4E phosphorylation.

5.
Urol Oncol ; 39(8): 496.e1-496.e8, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-33551249

RESUMO

BACKGROUND: Perioperative blood transfusion (PBT) has been associated with worse outcomes across tumor types, including bladder cancer. We report our institutional experience with PBT utilization in the setting of radical cystectomy (RC) for patients with bladder cancer, exploring whether timing of PBT receipt influences perioperative and oncologic outcomes. METHODS: Consecutive patients with bladder cancer treated with RC were identified. PBT was defined as red blood cell transfusion during RC or the postoperative admission. Clinicopathologic and peri and/or postoperative parameters were extracted and compared between patients who did and did not receive PBT using Mann Whitney U Test, chi-square, and log-rank test. Overall (OS) and recurrence-free survival (RFS) were estimated with the Kaplan Meier method. Univariate/multivariate logistic and Cox proportional hazards regression were used to identify variables associated with postoperative and oncologic outcomes, respectively. RESULTS: The cohort consisted of 747 patients (77% men; median age 67 years). Median follow-up was 61.5 months (95% CI 55.8-67.2) At least one postoperative complication (90-day morbidity) occurred in 394 (53%) patients. Median OS and RFS were 91.8 months (95% CI: 76.0-107.6) and 66.0 months (95% CI: 48.3-83.7), respectively. On multivariate analysis, intraoperative, but not postoperative, BT was independently associated with shorter OS (HR: 1.74, 95% CI: 1.32-2.29) and RFS (HR: 1.55, 95%CI: 1.20-2.01), after adjusting for relevant clinicopathologic variables. PBT (intra- or post- operative) was significantly associated with prolonged postoperative hospitalization ≥10 days. CONCLUSIONS: Intraoperative BT was associated with inferior OS and RFS, and PBT overall was associated with prolonged hospitalization following RC. Further studies are needed to validate this finding and explore potential causes for this observation.

6.
Sci Rep ; 11(1): 4609, 2021 Feb 25.
Artigo em Inglês | MEDLINE | ID: mdl-33633154

RESUMO

Bladder cancer is among the most prevalent cancers worldwide. Currently, few bladder cancer models have undergone thorough characterization to assess their fidelity to patient tumors, especially upon propagation in the laboratory. Here, we establish and molecularly characterize CoCaB 1, an aggressive cisplatin-resistant muscle-invasive bladder cancer patient-derived xenograft (PDX) and companion organoid system. CoCaB 1 was a subcutaneous PDX model reliably transplanted in vivo and demonstrated an acceleration in growth upon serial transplantation, which was reflected in organoid and 2D cell culture systems. Transcriptome analysis revealed progression towards an increasingly proliferative and stem-like expression profile. Gene expression differences between organoid and PDX models reflected expected differences in cellular composition, with organoids enriched in lipid biosynthesis and metabolism genes and deprived of extracellular components observed in PDXs. Both PDX and organoid models maintained the histological fidelity and mutational heterogeneity of their parental tumor. This study establishes the CoCaB 1 PDX and organoid system as companion representative tumor models for the development of novel bladder cancer therapies.

7.
Clin Genitourin Cancer ; 19(2): 144-154, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-33160889

RESUMO

BACKGROUND: Micropapillary urothelial carcinoma (MPC) is a rare urothelial carcinoma variant with conflicting data guiding clinical practice. In this study, we explored oncologic outcomes in relation to neoadjuvant chemotherapy (NAC) in a retrospective cohort of patients with MPC, alongside data from Surveillance, Epidemiology, and End Results (SEER)-Medicare. PATIENTS AND METHODS: We retrospectively identified patients with MPC or conventional urothelial carcinoma (CUC) without any variant histology undergoing radical cystectomy (RC) in our institution (2003-2018). SEER-Medicare was also queried to identify patients diagnosed with MPC (2004-2015). Clinicopathologic data and treatment modalities were extracted. Overall survival (OS) was estimated with the Kaplan-Meier method. Mann-Whitney-Wilcoxon and chi-square tests were used for comparative analysis and Cox regression for identifying clinical covariates associated with OS. RESULTS: Our institutional database yielded 46 patients with MPC and 457 with CUC. In SEER-Medicare, 183 patients with MPC were identified, and 63 (34%) underwent RC. In the institutional cohort, patients with MPC had significantly higher incidence of cN+ (17% vs. 8%), pN+ stage (30% vs. 17%), carcinoma-in-situ (43% vs. 25%), and lymphovascular invasion (30% vs. 16%) at RC versus those with CUC (all P < .05). Pathologic complete response (ypT0N0) to NAC was 33% for MPC and 35% for CUC (P = .899). Median OS was lower for institutional MPC versus CUC in univariate analysis (43.6 vs. 105.3 months, P = .006); however, MPC was not independently associated with OS in the multivariate model. Median OS was 25 months in the SEER MPC cohort for patients undergoing RC, while NAC was not associated with improved OS in that group. CONCLUSION: Pathologic response to NAC was not significantly different between MPC and CUC, while MPC histology was not an independent predictor of OS. Further studies are needed to better understand biological mechanisms behind its aggressive features as well as the role of NAC in this histology variant.

8.
Curr Biol ; 31(1): 128-137.e5, 2021 Jan 11.
Artigo em Inglês | MEDLINE | ID: mdl-33157031

RESUMO

The translation machinery is composed of a myriad of proteins and RNAs whose levels must be coordinated to efficiently produce proteins without wasting energy or substrate. However, protein synthesis is clearly not always perfectly tuned to its environment, as disruption of translation machinery components can lengthen lifespan and stress survival. While much has been learned from bacteria and yeast about translational regulation, much less is known in metazoans. In a screen for mutations protecting C. elegans from hypoxic stress, we isolated multiple genes impacting protein synthesis: a ribosomal RNA helicase gene, tRNA biosynthesis genes, and a gene controlling amino acid availability. To define better the mechanisms by which these genes impact protein synthesis, we performed a second screen for suppressors of the conditional developmental arrest phenotype of the RNA helicase mutant and identified genes involved in ribosome biogenesis. Surprisingly, these suppressor mutations restored normal hypoxic sensitivity and protein synthesis to the tRNA biogenesis mutants, but not to the mutant reducing amino acid uptake. Proteomic analysis demonstrated that reduced tRNA biosynthetic activity produces a selective homeostatic reduction in ribosomal subunits, thereby offering a mechanism for the suppression results. Our study uncovers an unrecognized higher-order-translation regulatory mechanism in a metazoan whereby ribosome biogenesis genes communicate with genes controlling tRNA abundance matching the global rate of protein synthesis with available resources.

9.
Cell Stem Cell ; 27(2): 270-283.e7, 2020 08 06.
Artigo em Inglês | MEDLINE | ID: mdl-32516567

RESUMO

Human skin tolerates a surprisingly high burden of oncogenic lesions. Although adult epidermis can suppress the expansion of individual mutant clones, the mechanisms behind tolerance to oncogene activation across broader regions of tissue are unclear. Here, we uncover a dynamic translational mechanism that coordinates oncogenic HRAS-induced hyperproliferation with loss of progenitor self-renewal to restrain aberrant growth and tumorigenesis. We identify translation initiator eIF2B5 as a central co-regulator of HRAS proliferation and cell fate choice. By coupling in vivo ribosome profiling with genetic screening, we provide direct evidence that oncogene-induced loss of progenitor self-renewal is driven by eIF2B5-mediated translation of ubiquitination genes. Ubiquitin ligase FBXO32 specifically inhibits epidermal renewal without affecting overall proliferation, thus restraining HRAS-driven tumorigenesis while maintaining normal tissue growth. Thus, oncogene-driven translation is not necessarily inherently tumor promoting but instead can manage widespread oncogenic stress by steering progenitor fate to prolong normal tissue growth.


Assuntos
Carcinogênese , Células Epidérmicas , Carcinogênese/genética , Diferenciação Celular , Proliferação de Células , Humanos , Oncogenes
10.
Bladder Cancer ; 6(1): 71-81, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-34109262

RESUMO

BACKGROUND: Plasmacytoid urothelial carcinoma is a rare bladder cancer variant with scarce data on outcomes and prognostic factors. OBJECTIVE: We report our institutional experience with this histology to determine response to neoadjuvant chemotherapy, definitive surgery and survival. METHODS: We conducted a retrospective chart review of consecutive patients with plasmacytoid, as well as conventional urothelial carcinoma (for comparison) seen in our institution (2007 - 2018). Baseline characteristics, clinicopathologic and treatment data were captured. T-test, chi-squared and log-rank test was used for group comparison. Kaplan Meier method was used for estimation of overall survival and Cox regression for identification of prognostic factors. RESULTS: 64 patients with plasmacytoid and 418 with conventional urothelial histology were identified; 53% of those with plasmacytoid presented with cT3/4 stage and 67% underwent extirpative surgery. Patients with plasmacytoid histology had higher rates of pT3/4 (65% vs. 28%), nodal disease (37% vs. 16%) and positive surgical margins (23% vs. 5%) compared to urothelial group (p < 0.01), as well as higher incidence of post-operative recurrence (47% vs. 29%, p = 0.05) and lower ypT0N0 rates after neoadjuvant chemotherapy (10% vs. 33%, p = 0.03). Plasmacytoid histology was associated with lower median overall survival compared to conventional urothelial (24 vs. 154 months, p < 0.01). CONCLUSIONS: Plasmacytoid urothelial carcinoma frequently presented with advanced stage at diagnosis and extirpative surgery, poor pathologic response to neoadjuvant chemotherapy, and inferior outcomes, when compared to conventional urothelial. Prospective trials evaluating upfront cystectomy versus preoperative chemotherapy and/or novel treatments should be considered.

11.
Nat Commun ; 10(1): 4596, 2019 10 10.
Artigo em Inglês | MEDLINE | ID: mdl-31601799

RESUMO

Many of the regulatory features governing erythrocyte specification, maturation, and associated disorders remain enigmatic. To identify new regulators of erythropoiesis, we utilize a functional genomic screen for genes affecting expression of the erythroid marker CD235a/GYPA. Among validating hits are genes coding for the N6-methyladenosine (m6A) mRNA methyltransferase (MTase) complex, including, METTL14, METTL3, and WTAP. We demonstrate that m6A MTase activity promotes erythroid gene expression programs through selective translation of ~300 m6A marked mRNAs, including those coding for SETD histone methyltransferases, ribosomal components, and polyA RNA binding proteins. Remarkably, loss of m6A marks results in dramatic loss of H3K4me3 marks across key erythroid-specific KLF1 transcriptional targets (e.g., Heme biosynthesis genes). Further, each m6A MTase subunit and a subset of their mRNAs targets are required for human erythroid specification in primary bone-marrow derived progenitors. Thus, m6A mRNA marks promote the translation of a network of genes required for human erythropoiesis.


Assuntos
Adenosina/análogos & derivados , Eritropoese/genética , Biossíntese de Proteínas , Adenosina/genética , Antígenos CD34/genética , Antígenos CD34/metabolismo , Células da Medula Óssea/fisiologia , Sistemas CRISPR-Cas , Proteínas de Ciclo Celular/genética , Linhagem Celular Tumoral , Regulação da Expressão Gênica , Histonas/genética , Histonas/metabolismo , Humanos , Fatores de Transcrição Kruppel-Like/genética , Fatores de Transcrição Kruppel-Like/metabolismo , Leucemia Eritroblástica Aguda/genética , Metiltransferases/genética , Regiões Promotoras Genéticas , Fatores de Processamento de RNA/genética , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Regulon
12.
Sci Transl Med ; 11(503)2019 07 31.
Artigo em Inglês | MEDLINE | ID: mdl-31366581

RESUMO

The androgen receptor (AR) is a driver of cellular differentiation and prostate cancer development. An extensive body of work has linked these normal and aberrant cellular processes to mRNA transcription; however, the extent to which AR regulates posttranscriptional gene regulation remains unknown. Here, we demonstrate that AR uses the translation machinery to shape the cellular proteome. We show that AR is a negative regulator of protein synthesis and identify an unexpected relationship between AR and the process of translation initiation in vivo. This is mediated through direct transcriptional control of the translation inhibitor 4EBP1. We demonstrate that lowering AR abundance increases the assembly of the eIF4F translation initiation complex, which drives enhanced tumor cell proliferation. Furthermore, we uncover a network of pro-proliferation mRNAs characterized by a guanine-rich cis-regulatory element that is particularly sensitive to eIF4F hyperactivity. Using both genetic and pharmacologic methods, we demonstrate that dissociation of the eIF4F complex reverses the proliferation program, resulting in decreased tumor growth and improved survival in preclinical models. Our findings reveal a druggable nexus that functionally links the processes of mRNA transcription and translation initiation in an emerging class of lethal AR-deficient prostate cancer.


Assuntos
Neoplasias da Próstata/metabolismo , Receptores Androgênicos/metabolismo , Regulon/fisiologia , Proteínas Adaptadoras de Transdução de Sinal/genética , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Animais , Proteínas de Ciclo Celular/genética , Proteínas de Ciclo Celular/metabolismo , Proliferação de Células/genética , Proliferação de Células/fisiologia , Humanos , Técnicas In Vitro , Íntrons/genética , Masculino , Camundongos , Neoplasias da Próstata/genética , Receptores Androgênicos/genética , Regulon/genética
13.
J Clin Invest ; 129(10): 4492-4505, 2019 07 30.
Artigo em Inglês | MEDLINE | ID: mdl-31361600

RESUMO

Metastatic castration-resistant prostate cancer (mCRPC) is a heterogeneous disease with diverse drivers of disease progression and mechanisms of therapeutic resistance. We conducted deep phenotypic characterization of CRPC metastases and patient-derived xenograft (PDX) lines using whole genome RNA sequencing, gene set enrichment analysis and immunohistochemistry. Our analyses revealed five mCRPC phenotypes based on the expression of well-characterized androgen receptor (AR) or neuroendocrine (NE) genes: (i) AR-high tumors (ARPC), (ii) AR-low tumors (ARLPC), (iii) amphicrine tumors composed of cells co-expressing AR and NE genes (AMPC), (iv) double-negative tumors (i.e. AR-/NE-; DNPC) and (v) tumors with small cell or NE gene expression without AR activity (SCNPC). RE1-silencing transcription factor (REST) activity, which suppresses NE gene expression, was lost in AMPC and SCNPC PDX models. However, knockdown of REST in cell lines revealed that attenuated REST activity drives the AMPC phenotype but is not sufficient for SCNPC conversion. We also identified a subtype of DNPC tumors with squamous differentiation and generated an encompassing 26-gene transcriptional signature that distinguished the five mCRPC phenotypes. Together, our data highlight the central role of AR and REST in classifying treatment-resistant mCRPC phenotypes. These molecular classifications could potentially guide future therapeutic studies and clinical trial design.


Assuntos
Perfilação da Expressão Gênica , Regulação Neoplásica da Expressão Gênica , Proteínas de Neoplasias , Neoplasias de Próstata Resistentes à Castração , Transcrição Genética , Humanos , Masculino , Metástase Neoplásica , Proteínas de Neoplasias/biossíntese , Proteínas de Neoplasias/genética , Células PC-3 , Neoplasias de Próstata Resistentes à Castração/classificação , Neoplasias de Próstata Resistentes à Castração/genética , Neoplasias de Próstata Resistentes à Castração/metabolismo , Neoplasias de Próstata Resistentes à Castração/patologia
14.
JCI Insight ; 52019 05 30.
Artigo em Inglês | MEDLINE | ID: mdl-31145100

RESUMO

BACKGROUND: Little is known about the genomic differences between metastatic urothelial carcinoma (LTUC) and upper tract urothelial carcinoma (UTUC). We compare genomic features of primary and metastatic UTUC and LTUC tumors in a cohort of patients with end stage disease. METHODS: We performed whole exome sequencing on matched primary and metastatic tumor samples (N=37) from 7 patients with metastatic UC collected via rapid autopsy. Inter- and intra-patient mutational burden, mutational signatures, predicted deleterious mutations, and somatic copy alterations (sCNV) were analyzed. RESULTS: We investigated 3 patients with UTUC (3 primary samples, 13 metastases) and 4 patients with LTUC (4 primary samples, 17 metastases). We found that sSNV burden was higher in metastatic LTUC compared to UTUC. Moreover, the APOBEC mutational signature was pervasive in metastatic LTUC and less so in UTUC. Despite a lower overall sSNV burden, UTUC displayed greater inter- and intra-individual genomic distances at the copy number level between primary and metastatic tumors than LTUC. Our data also indicate that metastatic UTUC lesions can arise from small clonal populations present in the primary cancer. Importantly, putative druggable mutations were found across patients with the majority shared across all metastases within a patient. CONCLUSIONS: Metastatic UTUC demonstrated a lower overall mutational burden but greater structural variability compared to LTUC. Our findings suggest that metastatic UTUC displays a greater spectrum of copy number divergence from LTUC. Importantly, we identified druggable lesions shared across metastatic samples, which demonstrate a level of targetable homogeneity within individual patients.


Assuntos
Carcinoma de Células de Transição/genética , Genômica , Neoplasias Urológicas/genética , Idoso , Autopsia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Mutação , Análise de Sequência , Sequenciamento Completo do Exoma
15.
Artigo em Inglês | MEDLINE | ID: mdl-31123724

RESUMO

PURPOSE: Ductal prostate cancer (dPC) is a rare variant of prostatic adenocarcinoma associated with poor outcomes. Although its histopathologic features are well characterized, the underlying molecular hallmarks of this aggressive subtype are not well described. We sought to provide a comprehensive overview of the spectrum of mutations associated with dPC. METHODS: Three case series across multiple institutions were assembled. All patients had a diagnosis of dPC, and histopathologic classification was confirmed by an expert genitourinary pathologist. Case series 1 included men who were prospectively enrolled in a tumor sequencing study at the University of Washington (n = 22). Case series 2 and 3 included archival samples from men treated at Johns Hopkins Hospital (n = 21) and University of Calgary (n = 8), respectively. Tumor tissue was sequenced on a targeted next-generation sequencing assay, UW-OncoPlex, according to previously published methods. The frequency of pathogenic/likely pathogenic mutations are reported. RESULTS: Overall, 25 patients (49%) had at least one DNA damage repair gene alteration, including seven (14%) with a mismatch repair gene mutation and 16 (31%) with a homologous repair mutation. Germline autosomal dominant mutations were confirmed or suspected in 10 patients (20%). Activating mutations in the PI3K pathway (n = 19; 37%), WNT pathway (n = 16; 31%), and MAPK pathway (n = 8; 16%) were common. CONCLUSION: This study strongly suggests that dPCs are enriched for actionable mutations, with approximately 50% of patients demonstrating DNA damage repair pathway alteration(s). Patients with dPC should be offered next-generation sequencing to guide standard-of-care treatment (eg, immune checkpoint inhibitors) or triaged toward an appropriate clinical trial (eg, poly [ADP-ribose] polymerase inhibitors).

16.
Trends Cancer ; 5(4): 245-262, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30961831

RESUMO

The 5' and 3' untranslated regions (UTRs) regulate crucial aspects of post-transcriptional gene regulation that are necessary for the maintenance of cellular homeostasis. When these processes go awry through mutation or misexpression of certain regulatory elements, the subsequent deregulation of oncogenic gene expression can drive or enhance cancer pathogenesis. Although the number of known cancer-related mutations in UTR regulatory elements has recently increased markedly as a result of advances in whole-genome sequencing, little is known about how the majority of these genetic aberrations contribute functionally to disease. In this review we explore the regulatory functions of UTRs, how they are co-opted in cancer, new technologies to interrogate cancerous UTRs, and potential therapeutic opportunities stemming from these regions.


Assuntos
Regulação Neoplásica da Expressão Gênica , Predisposição Genética para Doença , Neoplasias/genética , RNA Mensageiro/genética , Regiões não Traduzidas , Regiões 3' não Traduzidas , Regiões 5' não Traduzidas , Animais , Sítios de Ligação , Estudos de Associação Genética , Humanos , Sítios Internos de Entrada Ribossomal , MicroRNAs/genética , Neoplasias/metabolismo , Neoplasias/patologia , Poliadenilação , Biossíntese de Proteínas , Sequências Reguladoras de Ácido Ribonucleico
17.
Sci Transl Med ; 10(439)2018 05 02.
Artigo em Inglês | MEDLINE | ID: mdl-29720449

RESUMO

Oncogenic lesions up-regulate bioenergetically demanding cellular processes, such as protein synthesis, to drive cancer cell growth and continued proliferation. However, the hijacking of these key processes by oncogenic pathways imposes onerous cell stress that must be mitigated by adaptive responses for cell survival. The mechanism by which these adaptive responses are established, their functional consequences for tumor development, and their implications for therapeutic interventions remain largely unknown. Using murine and humanized models of prostate cancer (PCa), we show that one of the three branches of the unfolded protein response is selectively activated in advanced PCa. This adaptive response activates the phosphorylation of the eukaryotic initiation factor 2-α (P-eIF2α) to reset global protein synthesis to a level that fosters aggressive tumor development and is a marker of poor patient survival upon the acquisition of multiple oncogenic lesions. Using patient-derived xenograft models and an inhibitor of P-eIF2α activity, ISRIB, our data show that targeting this adaptive brake for protein synthesis selectively triggers cytotoxicity against aggressive metastatic PCa, a disease for which presently there is no cure.


Assuntos
Fator de Iniciação 2 em Eucariotos/metabolismo , Neoplasias da Próstata/metabolismo , Animais , Antineoplásicos/uso terapêutico , Humanos , Masculino , Camundongos , Neoplasias da Próstata/tratamento farmacológico , Resposta a Proteínas não Dobradas/efeitos dos fármacos , Resposta a Proteínas não Dobradas/fisiologia
18.
Urol Oncol ; 36(7): 342.e7-342.e14, 2018 07.
Artigo em Inglês | MEDLINE | ID: mdl-29657089

RESUMO

BACKGROUND: The mechanistic target of rapamycin (mTOR) has been implicated in driving tumor biology in multiple malignancies, including urothelial carcinoma (UC). We investigate how mTOR and phosphorylated mTOR (pmTOR) protein expression correlate with chemoresponsiveness in the tumor and its microenvironment at final pathologic staging after neoadjuvant chemotherapy (NAC). METHODS: A single-institution retrospective analysis was performed on 62 patients with cT2-4Nany UC undergoing NAC followed by radical cystectomy. Diagnostic (transurethral resection specimens, TURBT) and postchemotherapy radical cystectomy specimens were evaluated for mTOR and pmTOR protein expression using immunohistochemistry of the tumor, peritumoral stroma, and normal surrounding stroma. Protein expression levels were compared between clinical and pathologic stage. Whole transcriptome analysis was performed to evaluate mRNA expression relative to mTOR pathway activation. RESULTS: Baseline levels of mTOR and pmTOR within TURBT specimens were not associated with clinical stage and response to chemotherapy overall. Nonresponders with advanced pathologic stage at cystectomy (ypT2-4/ypTanyN+) had significantly elevated mTOR tumor staining (P = 0.006) and a sustained mTOR and pmTOR staining in the peritumoral and surrounding normal stroma (NS). Several genes relevant to mTOR activity were found to be up-regulated in the tumors of nonresponders. Remarkably, complete responders at cystectomy (ypT0) had significant decreases in both mTOR and pmTOR protein expression in the peritumoral and normal stroma (P = 0.01-0.03). CONCLUSIONS: Our results suggest that mTOR pathway activity is increased in tumor and sustained in its microenvironment in patients with adverse pathologic findings at cystectomy. These findings suggest the relevance of targeting this pathway in bladder cancer.


Assuntos
Biomarcadores Tumorais/metabolismo , Cistectomia/métodos , Serina-Treonina Quinases TOR/metabolismo , Microambiente Tumoral , Neoplasias da Bexiga Urinária/patologia , Idoso , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Estudos Retrospectivos , Taxa de Sobrevida , Resultado do Tratamento , Neoplasias da Bexiga Urinária/cirurgia
19.
Cell ; 173(5): 1204-1216.e26, 2018 05 17.
Artigo em Inglês | MEDLINE | ID: mdl-29628141

RESUMO

Pseudouridylation (Ψ) is the most abundant and widespread type of RNA epigenetic modification in living organisms; however, the biological role of Ψ remains poorly understood. Here, we show that a Ψ-driven posttranscriptional program steers translation control to impact stem cell commitment during early embryogenesis. Mechanistically, the Ψ "writer" PUS7 modifies and activates a novel network of tRNA-derived small fragments (tRFs) targeting the translation initiation complex. PUS7 inactivation in embryonic stem cells impairs tRF-mediated translation regulation, leading to increased protein biosynthesis and defective germ layer specification. Remarkably, dysregulation of this posttranscriptional regulatory circuitry impairs hematopoietic stem cell commitment and is common to aggressive subtypes of human myelodysplastic syndromes. Our findings unveil a critical function of Ψ in directing translation control in stem cells with important implications for development and disease.


Assuntos
Transferases Intramoleculares/metabolismo , Biossíntese de Proteínas , Pseudouridina/metabolismo , RNA de Transferência/metabolismo , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Animais , Proteínas de Ciclo Celular , Diferenciação Celular , Fatores de Iniciação em Eucariotos/metabolismo , Células-Tronco Hematopoéticas/citologia , Células-Tronco Hematopoéticas/metabolismo , Células-Tronco Embrionárias Humanas/citologia , Células-Tronco Embrionárias Humanas/metabolismo , Humanos , Transferases Intramoleculares/antagonistas & inibidores , Transferases Intramoleculares/genética , Camundongos , Camundongos Endogâmicos NOD , Camundongos SCID , Síndromes Mielodisplásicas/patologia , Conformação de Ácido Nucleico , Fosfoproteínas/metabolismo , Proteína I de Ligação a Poli(A)/antagonistas & inibidores , Proteína I de Ligação a Poli(A)/genética , Proteína I de Ligação a Poli(A)/metabolismo , Interferência de RNA , RNA Interferente Pequeno/metabolismo , Nicho de Células-Tronco
20.
Invest New Drugs ; 36(3): 458-467, 2018 06.
Artigo em Inglês | MEDLINE | ID: mdl-29508246

RESUMO

Background MLN0128 is a first-in-class, dual mTOR inhibitor with potential to outperform standard rapalogs through inhibition of TORC1 and TORC2. This phase II study was designed to assess antitumor activity of MLN0128 in metastatic castration-resistant prostate cancer (mCRPC). Methods Eligible patients had mCRPC previously treated with abiraterone acetate and/or enzalutamide. Five patients started MLN0128 at 5 mg once daily, subsequently dose reduced to 4 mg because of toxicity. Four subsequent patients started MLN0128 at 4 mg daily. Primary endpoint was progression-free survival at 6 months. Results Nine patients were enrolled and median time on treatment was 11 weeks (range: 3-30). Best response was stable disease. All patients had a rise in PSA on treatment, with a median 159% increase from baseline (range: 12-620%). Median baseline circulating tumor cell count was 1 cell/mL (range: 0-40); none had a decrease in cell count posttreatment. Grade ≤ 2 adverse events included fatigue, anorexia, and rash. The most common serious adverse events were grade 3 dyspnea and maculopapular rash. Eight patients discontinued treatment early because of radiographic progression (n = 1), grade 3 toxicity (n = 5), or investigator discretion (n = 2). Four patients had immediate PSA decline following drug discontinuation, suggesting MLN0128 could cause compensatory increase of androgen receptor (AR) activity. Correlative studies of pretreatment and posttreatment biopsy specimens revealed limited inhibition of AKT phosphorylation, 4EBP1 phosphorylation, and eIF4E activity. Conclusions Clinical efficacy of MLN0128 in mCRPC was limited likely due to dose reductions secondary to toxicity, PSA kinetics suggesting AR activation resulting from mTOR inhibition, and poor inhibition of mTOR signaling targets.


Assuntos
Benzoxazóis/uso terapêutico , Neoplasias de Próstata Resistentes à Castração/tratamento farmacológico , Neoplasias de Próstata Resistentes à Castração/patologia , Pirimidinas/uso terapêutico , Serina-Treonina Quinases TOR/antagonistas & inibidores , Idoso , Benzoxazóis/efeitos adversos , Fator de Iniciação 4E em Eucariotos/metabolismo , Humanos , Masculino , Pessoa de Meia-Idade , Metástase Neoplásica , Células Neoplásicas Circulantes/patologia , Antígeno Prostático Específico/metabolismo , Pirimidinas/efeitos adversos , Transdução de Sinais , Resultado do Tratamento
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