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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.
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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-TroncoRESUMO
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.
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Proliferação de Células , Fibroblastos/metabolismo , Mitocôndrias/metabolismo , Proteínas Mitocondriais/biossíntese , Pressão Osmótica , Biossíntese de Proteínas , Ribossomos/metabolismo , Adaptação Fisiológica , Trifosfato de Adenosina/metabolismo , Animais , Códon de Iniciação , Fibroblastos/patologia , Células HEK293 , Humanos , Cinética , Camundongos , Mitocôndrias/genética , Mitocôndrias/patologia , Proteínas Mitocondriais/genética , Ribossomos/genética , Transdução de SinaisRESUMO
Translational control is critical for cell fate transitions during development, lineage specification, and tumorigenesis. Here, we show that the transcription factor double homeobox protein 4 (DUX4), and its previously characterized transcriptional program, broadly regulates translation to change the cellular proteome. DUX4 is a key regulator of zygotic genome activation in human embryos, whereas misexpression of DUX4 causes facioscapulohumeral muscular dystrophy (FSHD) and is associated with MHC-I suppression and immune evasion in cancer. We report that translation initiation and elongation factors are disrupted downstream of DUX4 expression in human myoblasts. Genome-wide translation profiling identified mRNAs susceptible to DUX4-induced translation inhibition, including those encoding antigen presentation factors and muscle lineage proteins, while DUX4-induced mRNAs were robustly translated. Endogenous expression of DUX4 in human FSHD myotubes and cancer cell lines also correlated with reduced protein synthesis and MHC-I presentation. Our findings reveal that DUX4 orchestrates cell state conversion by suppressing the cellular proteome while maintaining translation of DUX4-induced mRNAs to promote an early developmental program.
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Proteínas de Homeodomínio , Distrofia Muscular Facioescapuloumeral , Fatores de Transcrição , Humanos , Proteínas de Homeodomínio/genética , Proteínas de Homeodomínio/metabolismo , Músculo Esquelético/metabolismo , Distrofia Muscular Facioescapuloumeral/genética , Distrofia Muscular Facioescapuloumeral/metabolismo , Proteoma/metabolismo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismoRESUMO
Historically, the ribosome has been viewed as a complex ribozyme with constitutive rather than regulatory capacity in mRNA translation. Here we identify mutations of the Ribosomal Protein L38 (Rpl38) gene in mice exhibiting surprising tissue-specific patterning defects, including pronounced homeotic transformations of the axial skeleton. In Rpl38 mutant embryos, global protein synthesis is unchanged; however the translation of a select subset of Homeobox mRNAs is perturbed. Our data reveal that RPL38 facilitates 80S complex formation on these mRNAs as a regulatory component of the ribosome to confer transcript-specific translational control. We further show that Rpl38 expression is markedly enriched in regions of the embryo where loss-of-function phenotypes occur. Unexpectedly, a ribosomal protein (RP) expression screen reveals dynamic regulation of individual RPs within the vertebrate embryo. Collectively, these findings suggest that RP activity may be highly regulated to impart a new layer of specificity in the control of gene expression and mammalian development.
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Padronização Corporal , Doenças do Desenvolvimento Ósseo/genética , Regulação da Expressão Gênica no Desenvolvimento , Proteínas de Homeodomínio/genética , Biossíntese de Proteínas , Proteínas Ribossômicas/metabolismo , Animais , Humanos , Camundongos , Camundongos Endogâmicos C57BL , Mutação , Organogênese , RNA Mensageiro/metabolismo , Proteínas Ribossômicas/genética , Ribossomos/metabolismo , Cauda/anormalidadesRESUMO
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.
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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 TratamentoRESUMO
The mammalian target of rapamycin (mTOR) kinase is a master regulator of protein synthesis that couples nutrient sensing to cell growth and cancer. However, the downstream translationally regulated nodes of gene expression that may direct cancer development are poorly characterized. Using ribosome profiling, we uncover specialized translation of the prostate cancer genome by oncogenic mTOR signalling, revealing a remarkably specific repertoire of genes involved in cell proliferation, metabolism and invasion. We extend these findings by functionally characterizing a class of translationally controlled pro-invasion messenger RNAs that we show direct prostate cancer invasion and metastasis downstream of oncogenic mTOR signalling. Furthermore, we develop a clinically relevant ATP site inhibitor of mTOR, INK128, which reprograms this gene expression signature with therapeutic benefit for prostate cancer metastasis, for which there is presently no cure. Together, these findings extend our understanding of how the 'cancerous' translation machinery steers specific cancer cell behaviours, including metastasis, and may be therapeutically targeted.
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Metástase Neoplásica , Neoplasias da Próstata/patologia , Biossíntese de Proteínas , Transdução de Sinais , Serina-Treonina Quinases TOR/metabolismo , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Animais , Benzoxazóis/farmacologia , Proteínas de Ciclo Celular , Linhagem Celular Tumoral , Movimento Celular/efeitos dos fármacos , Movimento Celular/genética , Fator de Iniciação 4E em Eucariotos/metabolismo , Fatores de Iniciação em Eucariotos/metabolismo , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Regulação Neoplásica da Expressão Gênica/genética , Genoma/genética , Humanos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Invasividade Neoplásica/genética , Metástase Neoplásica/tratamento farmacológico , Metástase Neoplásica/genética , Fosfoproteínas/metabolismo , Neoplasias da Próstata/tratamento farmacológico , Neoplasias da Próstata/genética , Pirimidinas/farmacologia , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Proteínas Repressoras/metabolismo , Serina-Treonina Quinases TOR/antagonistas & inibidoresRESUMO
LESSONS LEARNED: The combination of standard dose abiraterone acetate and BEZ235, a pan-class I PI3K and mTORC1/2 inhibitor, was poorly tolerated in men with progressive mCRPC.Although the clinical development of BEZ235 has been discontinued in prostate cancer, agents that more selectively target PI3K-AKT-mTOR signaling may have a more favorable therapeutic index and should continue to be explored. BACKGROUND: Androgen receptor (AR) and phosphatidylinositol-3 kinase (PI3K) signaling are two commonly perturbed pathways in prostate cancer. Preclinical data have shown that the two pathways compensate for each other when one is inhibited, and combined inhibition of AR and PI3K signaling may be a viable strategy to prevent or overcome castration resistance. METHODS: This phase I study evaluated the safety and tolerability of abiraterone acetate and prednisone combined with BEZ235, a dual PI3K and mTORC1/2 inhibitor, in men with progressive metastatic castration resistant prostate cancer (mCRPC) who have not received prior chemotherapy. RESULTS: Six patients (n = 6) were treated at the starting dose level of abiraterone acetate 1,000 mg with prednisone 5 mg twice daily and BEZ235 200 mg twice daily in a 3 + 3 dose escalation design. The study was terminated early because three of the six patients (50%) experienced dose-limiting toxicities: grade 3 mucositis, grade 3 hypotension, and grade 4 dyspnea and pneumonitis. All six patients had previously progressed on abiraterone/prednisone. The median treatment duration was 27 days (range: 3-130 days). No prostate-specific antigen (PSA) decline or objective response were observed. CONCLUSION: The combination of standard-dose abiraterone/prednisone with BEZ235 200 mg twice daily was poorly tolerated in patients with mCRPC. The on-target and off-target effects of dual PI3K and mTORC inhibition likely contributed to the unacceptable toxicity profile. The Oncologist 2017;22:503-e43.
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Acetato de Abiraterona/administração & dosagem , Protocolos de Quimioterapia Combinada Antineoplásica/administração & dosagem , Imidazóis/administração & dosagem , Neoplasias de Próstata Resistentes à Castração/tratamento farmacológico , Quinolinas/administração & dosagem , Acetato de Abiraterona/efeitos adversos , Idoso , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos/patologia , Humanos , Imidazóis/efeitos adversos , Masculino , Pessoa de Meia-Idade , Inibidores de Fosfoinositídeo-3 Quinase , Antígeno Prostático Específico/sangue , Neoplasias de Próstata Resistentes à Castração/sangue , Neoplasias de Próstata Resistentes à Castração/genética , Neoplasias de Próstata Resistentes à Castração/patologia , Quinolinas/efeitos adversos , Receptores Androgênicos/genética , Transdução de Sinais/efeitos dos fármacos , Serina-Treonina Quinases TOR/antagonistas & inibidoresRESUMO
MOTIVATION: The translational landscape of diverse cellular systems remains largely uncharacterized. A detailed understanding of the control of gene expression at the level of messenger RNA translation is vital to elucidating a systems-level view of complex molecular programs in the cell. Establishing the degree to which such post-transcriptional regulation can mediate specific phenotypes is similarly critical to elucidating the molecular pathogenesis of diseases such as cancer. Recently, methods for massively parallel sequencing of ribosome-bound fragments of messenger RNA have begun to uncover genome-wide translational control at codon resolution. Despite its promise for deeply characterizing mammalian proteomes, few analytical methods exist for the comprehensive analysis of this paired RNA and ribosome data. RESULTS: We describe the Babel framework, an analytical methodology for assessing the significance of changes in translational regulation within cells and between conditions. This approach facilitates the analysis of translation genome-wide while allowing statistically principled gene-level inference. Babel is based on an errors-in-variables regression model that uses the negative binomial distribution and draws inference using a parametric bootstrap approach. We demonstrate the operating characteristics of Babel on simulated data and use its gene-level inference to extend prior analyses significantly, discovering new translationally regulated modules under mammalian target of rapamycin (mTOR) pathway signaling control.
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Perfilação da Expressão Gênica , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Biossíntese de Proteínas/genética , RNA Mensageiro/metabolismo , Ribossomos/metabolismo , Software , Algoritmos , Animais , Códon/metabolismo , Simulação por Computador , Regulação da Expressão Gênica , Humanos , RNA Mensageiro/genética , Ribossomos/genética , Serina-Treonina Quinases TOR/genética , Serina-Treonina Quinases TOR/metabolismoRESUMO
RNAs undergo a complex choreography of metabolic processes in human cells that are regulated by thousands of RNA-associated proteins. While the effects of individual RNA-associated proteins on RNA metabolism have been extensively characterized, the full complement of regulators for most RNA metabolic events remain unknown. Here we present a massively parallel RNA-linked CRISPR (ReLiC) screening approach to measure the responses of diverse RNA metabolic events to knockout of 2,092 human genes encoding all known RNA-associated proteins. ReLiC screens highlight modular interactions between gene networks regulating splicing, translation, and decay of mRNAs. When combined with biochemical fractionation of polysomes, ReLiC reveals striking pathway-specific coupling between growth fitness and mRNA translation. Perturbing different components of the translation and proteostasis machineries have distinct effects on ribosome occupancy, while perturbing mRNA transcription leaves ribosome occupancy largely intact. Isoform-selective ReLiC screens capture differential regulation of intron retention and exon skipping by SF3b complex subunits. Chemogenomic screens using ReLiC decipher translational regulators upstream of mRNA decay and uncover a role for the ribosome collision sensor GCN1 during treatment with the anti-leukemic drug homoharringtonine. Our work demonstrates ReLiC as a versatile platform for discovering and dissecting regulatory principles of human RNA metabolism.
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Available genetically defined cancer models are limited in genotypic and phenotypic complexity and underrepresent the heterogeneity of human cancer. Here, we describe a combinatorial genetic strategy applied to an organoid transformation assay to rapidly generate diverse, clinically relevant bladder and prostate cancer models. Importantly, the clonal architecture of the resultant tumors can be resolved using single-cell or spatially resolved next-generation sequencing to uncover polygenic drivers of cancer phenotypes.
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Neoplasias , Masculino , Humanos , Genótipo , Fenótipo , Neoplasias/genética , Estudos de Associação GenéticaRESUMO
Introduction: Bladder preservation with concurrent chemoradiotherapy after maximum transurethral resection of bladder tumor is an alternative to radical cystectomy in select patients with muscle invasive bladder cancer (MIBC). Concurrent administration of radio-sensitizing chemotherapy and radiation therapy (RT) has been shown to have superior disease control compared with RT alone and can often be administered with modest added toxicity. We sought to describe national patterns of chemotherapy use. Methods: The linked surveillance, epidemiology, and end results (SEER)-Medicare database was used to identify patients with cT2-4, N0/X, M0/X BC who received radiation between 2004 and 2018. Data on demographics, clinicopathologic factors, therapy and outcomes were extracted. Concurrent utilization of chemotherapy with RT was also identified (CRT). Multivariate logistic regression (MVA) models were used to explore factors associated with receipt of chemotherapy and overall survival (OS). Results: 2190 patients met inclusion criteria. Of these, 850 (38.8%) received no chemotherapy. Among those receiving chemotherapy, the most frequent regimens were single agent carboplatin, cisplatin, or gemcitabine. Factors that were independently associated with decreased likelihood of chemotherapy use were increasing age (OR 0.93, CI 0.92 - 0.95), Hispanic race (compared with White, OR 0.62, CI 0.39 - 0.99), cT3 or T4 (compared with cT2, OR 0.70, CI 0.55 - 0.90), and lower National Cancer Institute comorbidity index (OR 0.60, CI 0.51 - 0.70) (p < 0.05). Variables independently associated with increased likelihood of receipt of chemotherapy were married status (OR 1.28, CI 1.06 - 1.54), higher socioeconomic status (OR 1.31, CI 1.06 - 1.64), and later year of diagnosis (OR 1.09, CI 1.06 - 1.12). Receipt of concurrent chemotherapy with RT was associated with superior OS compared with RT alone. Conclusion: Over a third of patients >/65 years old receiving curative-intent RT for MIBC do not receive concurrent chemotherapy. Considering the improvement in oncologic outcomes with CRT over RT alone and more options, such as low dose gemcitabine which can be administered with modest toxicity, efforts are needed to identify barriers to utilization and increase the use of radio-sensitizing chemotherapy.
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OBJECTIVES: Patients with histologic subtype bladder cancer (HSBC) suffer worse outcomes than those with conventional urothelial carcinoma (UC). We sought to characterize the use of adjuvant chemotherapy (AC) in HSBC after radical cystectomy (RC) using the National Cancer Database (NCDB). MATERIALS AND METHODS: We retrospectively queried the NCDB (2006-2019) for patients with non-metastatic bladder cancer (BC) who underwent RC (N = 45,797). Patients were stratified by histologic subtype and receipt of AC. Multivariable logistic regression determined associations of demographic and clinicopathologic features with receipt of AC. Multivariable Cox regression evaluated associations between receipt of any AC and overall survival (OS). RESULTS: We identified 4,469 patients with HSBC classified as squamous, adenocarcinoma, small cell, sarcomatoid, micropapillary, or plasmacytoid. Squamous comprised 31% of the HSBC cohort, followed by small cells and micropapillary. Black patients were presented with a higher prevalence of adenocarcinoma (119/322, 37.0%). Use of AC was highest in plasmacytoid and small cell (30% each) and lowest in squamous (11%). Neuroendocrine histology was independently associated with greater odds of receiving AC (HR 1.6, 95% CI 1.37-1.87), while squamous cell histology was associated with lower odds (HR 0.61, 95% CI 0.53-0.71). On multivariable Cox regression analysis, treatment with AC was associated with significantly longer OS (HR 0.69, 95% CI 0.59-0.81) and for squamous, sarcomatoid, and micropapillary cohorts after stratified by subtype. CONCLUSIONS: AC was variably used among patients with HSBC and was associated with OS benefit in such patients.
Assuntos
Cistectomia , Neoplasias da Bexiga Urinária , Humanos , Neoplasias da Bexiga Urinária/patologia , Neoplasias da Bexiga Urinária/cirurgia , Neoplasias da Bexiga Urinária/mortalidade , Neoplasias da Bexiga Urinária/tratamento farmacológico , Masculino , Feminino , Idoso , Quimioterapia Adjuvante/estatística & dados numéricos , Estudos Retrospectivos , Pessoa de Meia-Idade , Carcinoma de Células de Transição/cirurgia , Carcinoma de Células de Transição/mortalidade , Carcinoma de Células de Transição/patologia , Carcinoma de Células de Transição/tratamento farmacológico , Taxa de SobrevidaRESUMO
Stentenbach and colleagues have unveiled a functional role of a human germline mutation found in the ribonuclease (RNase) Z enzyme, ELAC2, in prostate cancer. Here, we discuss the importance of these findings in enhancing our understanding of how risk variants enable prostate cancer progression and the post-transcriptional mechanisms underlying oncogenesis.
Assuntos
Neoplasias da Próstata , Masculino , Humanos , Alelos , Neoplasias da Próstata/genética , Predisposição Genética para Doença , Proteínas de Neoplasias/genéticaRESUMO
Prolonged treatment with androgen deprivation therapy (ADT) inevitably leads to castration-resistant prostate cancer (CRPC). Development of novel androgen-targeting agents and chemo/radiotherapies has resulted in improved survival. However, metastatic CRPC remains incurable. New therapeutics are greatly needed, and exploration of novel pathways such as the mechanisms underlying prostate cancer cell proliferation could potentially augment the natural course of CRPC. In the latest issue of Cancer Research, Rawat and colleagues delved deeply into the mechanistic role of citron kinase (CIT) in orchestrating prostate cancer proliferation and revealed its catalytic activity as a druggable target for treatment-resistant prostate cancer. The researchers utilized in vitro and in vivo methodologies to elucidate the function of CIT in mediating uncontrolled interphase progression and prostate cancer growth. Furthermore, the authors employed both androgen receptor-dependent and independent models to validate the significance of CIT kinase activity as a crucial factor in driving treatment-resistant prostate cancer growth. At a mechanistic level they determined that the E2F2-Skp2-p27 axis regulates CIT expression. Finally, they defined the landscape of CIT substrates in prostate cancer that encompasses a spectrum of cellular functions that spans key proliferation regulators to alternative splicing events. This comprehensive work provides insights into CIT as a potential biomarker for prostate cancer treatment resistance and disease progression and establishes the CIT kinase domain as a druggable target in CRPC. See related article by Rawat et al., p. 4142.
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Neoplasias de Próstata Resistentes à Castração , Masculino , Humanos , Neoplasias de Próstata Resistentes à Castração/metabolismo , Androgênios , Antagonistas de Androgênios , Receptores Androgênicos/metabolismo , Próstata/patologia , Linhagem Celular TumoralRESUMO
3' untranslated region (3' UTR) somatic mutations represent a largely unexplored avenue of alternative oncogenic gene dysregulation. To determine the significance of 3' UTR mutations in disease, we identify 3' UTR somatic variants across 185 advanced prostate tumors, discovering 14,497 single-nucleotide mutations enriched in oncogenic pathways and 3' UTR regulatory elements. By developing two complementary massively parallel reporter assays, we measure how thousands of patient-based mutations affect mRNA translation and stability and identify hundreds of functional variants that allow us to define determinants of mutation significance. We demonstrate the clinical relevance of these mutations, observing that CRISPR-Cas9 endogenous editing of distinct variants increases cellular stress resistance and that patients harboring oncogenic 3' UTR mutations have a particularly poor prognosis. This work represents an expansive view of the extent to which disease-relevant 3' UTR mutations affect mRNA stability, translation, and cancer progression, uncovering principles of regulatory functionality and potential therapeutic targets in previously unexplored regulatory regions.
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Genômica , Sequências Reguladoras de Ácido Nucleico , Humanos , Regiões 3' não Traduzidas/genética , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Mutação/genética , Regiões 5' não TraduzidasRESUMO
Available genetically-defined cancer models are limited in genotypic and phenotypic complexity and underrepresent the heterogeneity of human cancer. Herein, we describe a combinatorial genetic strategy applied to an organoid transformation assay to rapidly generate diverse, clinically relevant bladder and prostate cancer models. Importantly, the clonal architecture of the resultant tumors can be resolved using single-cell or spatially resolved next-generation sequencing to uncover polygenic drivers of cancer phenotypes.
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BACKGROUND: Nectin-4 and Trop-2 are transmembrane targets of FDA-approved antibody-drug conjugates (ADC) Enfortumab-vedotin (EV) and Sacituzumab govitecan (SG), respectively, for the treatment of metastatic urothelial carcinoma (mUC). The expression and role of Nectin-4 and Trop-2 in mUC variant histology is poorly described. MATERIALS AND METHODS: We evaluate membranous and cytoplasmic protein expression, and mRNA levels of Nectin-4 and Trop-2 within matched primary and metastatic mUC samples to determine heterogeneity of ADC targets in mUC variants. RESULTS: Patients with mUC were consented for rapid autopsy immediately after death. Tissues from matched primary and metastatic lesions were collected. A total of 67 specimens from 20 patients were analyzed: 27 were UC, 17 plasmacytoid (PUC), 18 UC with squamous differentiation (UCSD), and 5 neuroendocrine (NE); 10 from primary and 57 from metastatic sites. All histology except NE expressed moderate-high levels of Nectin-4 and Trop-2 by both immunohistochemistry and RNAseq. Nectin-4 demonstrated prominent cytoplasmic staining in metastatic PUC and UCSD. Trop-2 demonstrated strong cytoplasmic and membrane staining in primary and metastatic tumors. Interestingly, Nectin-4 and Trop-2 expression are positively correlated at both mRNA and protein levels. CONCLUSION: UC and non-NE variants express notable level of Nectin-4 and Trop-2 in both primary and metastatic lesions. Membrane staining of Nectin-4 and Trop-2 is present but cytoplasmic staining is a more common event in both mUC and mUC variant histology. These findings support evaluation of EV and SG in heavily treated variant histology BC and urge attention on the clinical relevance of cytoplasmic localization of ADC targets.
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Carcinoma de Células de Transição , Imunoconjugados , Neoplasias da Bexiga Urinária , Humanos , Nectinas , Carcinoma de Células de Transição/tratamento farmacológico , Autopsia , Neoplasias da Bexiga Urinária/genética , Neoplasias da Bexiga Urinária/tratamento farmacológico , Imunoconjugados/uso terapêutico , RNA Mensageiro/genéticaRESUMO
We uncover a tumor-suppressive process in urothelium called transcriptional-translational conflict caused by deregulation of the central chromatin remodeling component ARID1A. Loss of Arid1a triggers an increase in a nexus of pro-proliferation transcripts, but a simultaneous inhibition of the eukaryotic elongation factor 2 (eEF2), which results in tumor suppression. Resolution of this conflict through enhancing translation elongation speed enables the efficient and precise synthesis of a network of poised mRNAs resulting in uncontrolled proliferation, clonogenic growth, and bladder cancer progression. We observe a similar phenomenon in patients with ARID1A-low tumors, which also exhibit increased translation elongation activity through eEF2. These findings have important clinical implications because ARID1A-deficient, but not ARID1A-proficient, tumors are sensitive to pharmacologic inhibition of protein synthesis. These discoveries reveal an oncogenic stress created by transcriptional-translational conflict and provide a unified gene expression model that unveils the importance of the crosstalk between transcription and translation in promoting cancer.
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Cromatina , Neoplasias da Bexiga Urinária , Humanos , Neoplasias da Bexiga Urinária/genéticaRESUMO
INTRODUCTION: To examine oncologic outcomes and response to neoadjuvant chemotherapy (NAC) in patients with sarcomatoid urothelial carcinoma (SUC) treated with radical cystectomy (RC). MATERIALS AND METHODS: We retrospectively queried our institutional database (2003-18) and Surveillance, Epidemiology, and End Results (SEER)-Medicare (2004-2015) for patients with cT2-4, N0-2, M0 SUC and conventional UC (CUC) treated with RC. Clinicopathologic characteristics were described using descriptive statistics (t test, χ2-test and log-rank-test for group comparison). Overall (OS) and recurrence-free-survival (RFS) after RC were estimated with the Kaplan Meier method and associations with OS were evaluated with Cox proportional hazards models. RESULTS: We identified 38 patients with SUC and 287 patients with CUC in our database, and 190 patients with SUC in SEER-Medicare. In the institutional cohort, patients with SUC versus CUC had higher rates of pT3/4 stage (66% vs. 35%, P < 0.001), lower rates of ypT0N0 (6% vs. 35%, P = .02), and worse median OS (17.5 vs. 120 months, P < .001). Further, patients with SUC in the institutional versus SEER-Medicare cohort had similar median OS (17.5 vs. 21 months). In both cohorts, OS was comparable between patients with SUC undergoing NAC+RC vs. RC alone (17.5 vs. 18.4 months, P = .98, institutional cohort; 24 vs. 20 months, P = .56, SEER cohort). In Cox proportional hazards models for the institutional RC cohort, SUC was independently associated with worse OS (HR 2.3, CI 1.4-3.8, P = .001). CONCLUSION: SUC demonstrates poor pathologic response to NAC and worse OS compared with CUC, with no OS benefit associated with NAC. A unique pattern of rapid abdominopelvic cystic recurrence was identified.
Assuntos
Carcinoma de Células de Transição , Neoplasias da Bexiga Urinária , Humanos , Idoso , Estados Unidos/epidemiologia , Carcinoma de Células de Transição/tratamento farmacológico , Carcinoma de Células de Transição/cirurgia , Neoplasias da Bexiga Urinária/tratamento farmacológico , Neoplasias da Bexiga Urinária/cirurgia , Neoplasias da Bexiga Urinária/patologia , Cistectomia/métodos , Estudos Retrospectivos , Terapia Neoadjuvante , Estimativa de Kaplan-Meier , MedicareRESUMO
Pancreatic ductal adenocarcinoma (PDAC) is classified into two key subtypes, classical and basal, with basal PDAC predicting worse survival. Using in vitro drug assays, genetic manipulation experiments, and in vivo drug studies in human patient-derived xenografts (PDXs) of PDAC, we found that basal PDACs were uniquely sensitive to transcriptional inhibition by targeting cyclin-dependent kinase 7 (CDK7) and CDK9, and this sensitivity was recapitulated in the basal subtype of breast cancer. We showed in cell lines, PDXs, and publicly available patient datasets that basal PDAC was characterized by inactivation of the integrated stress response (ISR), which leads to a higher rate of global mRNA translation. Moreover, we identified the histone deacetylase sirtuin 6 (SIRT6) as a critical regulator of a constitutively active ISR. Using expression analysis, polysome sequencing, immunofluorescence, and cycloheximide chase experiments, we found that SIRT6 regulated protein stability by binding activating transcription factor 4 (ATF4) in nuclear speckles and protecting it from proteasomal degradation. In human PDAC cell lines and organoids as well as in murine PDAC genetically engineered mouse models where SIRT6 was deleted or down-regulated, we demonstrated that SIRT6 loss both defined the basal PDAC subtype and led to reduced ATF4 protein stability and a nonfunctional ISR, causing a marked vulnerability to CDK7 and CDK9 inhibitors. Thus, we have uncovered an important mechanism regulating a stress-induced transcriptional program that may be exploited with targeted therapies in particularly aggressive PDAC.