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BACKGROUND: Metabolic plasticity mediates breast cancer survival, growth, and immune evasion during metastasis. However, how tumor cell metabolism is influenced by and feeds back to regulate breast cancer progression are not fully understood. We identify hypoxia-mediated suppression of pyruvate carboxylase (PC), and subsequent induction of lactate production, as a metabolic regulator of immunosuppression. METHODS: We used qPCR, immunoblot, and reporter assays to characterize repression of PC in hypoxic primary tumors. Steady state metabolomics were used to identify changes in metabolite pools upon PC depletion. In vivo tumor growth and metastasis assays were used to evaluate the impact of PC manipulation and pharmacologic inhibition of lactate transporters. Immunohistochemistry, flow cytometry, and global gene expression analyzes of tumor tissue were employed to characterize the impact of PC depletion on tumor immunity. RESULTS: PC is essential for metastatic colonization of the lungs. In contrast, depletion of PC in tumor cells promotes primary tumor growth. This effect was only observed in immune competent animals, supporting the hypothesis that repression of PC can suppress anti-tumor immunity. Exploring key differences between the pulmonary and mammary environments, we demonstrate that hypoxia potently downregulated PC. In the absence of PC, tumor cells produce more lactate and undergo less oxidative phosphorylation. Inhibition of lactate metabolism was sufficient to restore T cell populations to PC-depleted mammary tumors. CONCLUSIONS: We present a dimorphic role for PC in primary mammary tumors vs. pulmonary metastases. These findings highlight a key contextual role for PC-directed lactate production as a metabolic nexus connecting hypoxia and antitumor immunity.
Assuntos
Neoplasias da Mama , Piruvato Carboxilase , Piruvato Carboxilase/metabolismo , Piruvato Carboxilase/genética , Animais , Feminino , Camundongos , Humanos , Neoplasias da Mama/patologia , Neoplasias da Mama/metabolismo , Neoplasias da Mama/genética , Neoplasias da Mama/imunologia , Linhagem Celular Tumoral , Ácido Láctico/metabolismo , Regulação Neoplásica da Expressão Gênica , Hipóxia Celular , Neoplasias Pulmonares/metabolismo , Neoplasias Pulmonares/patologia , Neoplasias Pulmonares/genética , Tolerância ImunológicaRESUMO
Accurately replicating and analyzing cellular responses to mechanical cues is vital for exploring metastatic disease progression. However, many of the existing in vitro platforms for applying mechanical stimulation seed cells on synthetic substrates. To better recapitulate physiological conditions, a novel actuating platform is developed with the ability to apply tensile strain on cells at various amplitudes and frequencies in a high-throughput multi-well culture plate using a physiologically-relevant substrate. Suspending fibrillar fibronectin across the body of the magnetic actuator provides a matrix representative of early metastasis for 3D cell culture that is not reliant on a synthetic substrate. This platform enables the culturing and analysis of various cell types in an environment that mimics the dynamic stretching of lung tissue during normal respiration. Metabolic activity, YAP activation, and morphology of breast cancer cells are analyzed within one week of cyclic stretching or static culture. Further, matrix degradation is significantly reduced in breast cancer cell lines with metastatic potential after actuation. These new findings demonstrate a clear suppressive cellular response due to cyclic stretching that has implications for a mechanical role in the dormancy and reactivation of disseminated breast cancer cells to macrometastases.
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The deubiquitinating enzyme (DUB) UCHL1 is implicated in various disease states including neurodegenerative disease and cancer. However, there is a lack of quality probe molecules to gain a better understanding on UCHL1 biology. To this end a study was carried out to fully characterize and optimize the irreversible covalent UCHL1 inhibitor VAEFMK. Structure-activity relationship studies identified modifications to improve activity versus the target and a full cellular characterization was carried out for the first time with this scaffold. The studies produced a new inhibitor, 34, with an IC50 value of 7.7 µM against UCHL1 and no observable activity versus the closest related DUB UCHL3. The molecule was also capable of selectively inhibiting UCHL1 in cells and did not demonstrate any discernible off-target toxicity. Finally, the molecule was used for initial probe studies to assess the role of UCHL1 role in proliferation of myeloma cells and migration behavior in small cell lung cancer cells making 34 a new tool to be used in the biological evaluation of UCHL1.
Assuntos
Antineoplásicos/farmacologia , Inibidores de Proteases/farmacologia , Ubiquitina Tiolesterase/antagonistas & inibidores , Antineoplásicos/síntese química , Antineoplásicos/química , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Relação Dose-Resposta a Droga , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Modelos Moleculares , Estrutura Molecular , Inibidores de Proteases/síntese química , Inibidores de Proteases/química , Relação Estrutura-Atividade , Ubiquitina Tiolesterase/metabolismoRESUMO
The deubiquitinase (DUB) ubiquitin C-terminal hydrolase L1 (UCHL1) is expressed primarily in the central nervous system under normal physiological conditions. However, UCHL1 is overexpressed in various aggressive forms of cancer with strong evidence supporting UCHL1 as an oncogene in lung, glioma, and blood cancers. In particular, the level of UCHL1 expression in these cancers correlates with increased invasiveness and metastatic behavior, as well as poor patient prognosis. Although UCHL1 is considered an oncogene with potential as a therapeutic target, there remains a significant lack of useful small-molecule probes to pharmacologically validate in vivo targeting of the enzyme. Herein, we describe the characterization of a new covalent cyanopyrrolidine-based UCHL1 inhibitory scaffold in biochemical and cellular studies to better understand the utility of this inhibitor in elucidating the role of UCHL1 in cancer biology.
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Inibidores Enzimáticos , Ubiquitina Tiolesterase , Sítios de Ligação , Linhagem Celular , Inibidores Enzimáticos/síntese química , Inibidores Enzimáticos/química , Inibidores Enzimáticos/metabolismo , Humanos , Estrutura Molecular , Ligação Proteica , Estrutura Secundária de Proteína , Ubiquitina Tiolesterase/antagonistas & inibidores , Ubiquitina Tiolesterase/metabolismoRESUMO
The state of protein phosphorylation can be a key determinant of cellular physiology such as early-stage cancer, but the development of phosphoproteins in biofluids for disease diagnosis remains elusive. Here we demonstrate a strategy to isolate and identify phosphoproteins in extracellular vesicles (EVs) from human plasma as potential markers to differentiate disease from healthy states. We identified close to 10,000 unique phosphopeptides in EVs isolated from small volumes of plasma samples. Using label-free quantitative phosphoproteomics, we identified 144 phosphoproteins in plasma EVs that are significantly higher in patients diagnosed with breast cancer compared with healthy controls. Several biomarkers were validated in individual patients using paralleled reaction monitoring for targeted quantitation. This study demonstrates that the development of phosphoproteins in plasma EV as disease biomarkers is highly feasible and may transform cancer screening and monitoring.
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Biomarcadores Tumorais , Neoplasias da Mama/metabolismo , Vesículas Extracelulares/metabolismo , Fosfoproteínas/metabolismo , Biomarcadores , Proteínas Sanguíneas , Neoplasias da Mama/sangue , Estudos de Casos e Controles , Análise por Conglomerados , Biologia Computacional/métodos , Exossomos/metabolismo , Feminino , Humanos , Fosfopeptídeos/metabolismo , Proteoma , Proteômica/métodos , Reprodutibilidade dos Testes , Espectrometria de Massas em Tandem , Fluxo de TrabalhoRESUMO
We report the selection of DNA-encoded small molecule libraries against protein targets within the cytosol and on the surface of live cells. The approach relies on generation of a covalent linkage of the DNA to protein targets by affinity labeling. This cross-linking event enables subsequent copurification by a tag on the recombinant protein. To access targets within cells, a cyclic cell-penetrating peptide is appended to DNA-encoded libraries for delivery across the cell membrane. As this approach assesses binding of DELs to targets in live cells, it provides a strategy for selection of DELs against challenging targets that cannot be expressed and purified as active.
Assuntos
Peptídeos Penetradores de Células/química , Proteínas/genética , Proteínas/metabolismo , Bibliotecas de Moléculas Pequenas/farmacologia , Peptídeos Penetradores de Células/metabolismo , Reagentes de Ligações Cruzadas/química , Citosol/efeitos dos fármacos , Citosol/metabolismo , DNA/química , Fluoresceínas/química , Células HEK293 , Humanos , Lipídeos , Peptídeos Cíclicos/química , Reação em Cadeia da Polimerase , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/metabolismo , Bibliotecas de Moléculas Pequenas/química , Tetra-Hidrofolato Desidrogenase/genética , Transfecção , Trimetoprima/farmacologiaRESUMO
As aberrant activity of protein kinases is observed in many disease states, these enzymes are common targets for therapeutics and detection of activity levels. The development of non-natural protein kinase substrates offers an approach to protein substrate competitive inhibitors, a class of kinase inhibitors with promise for improved specificity. Also, kinase activity detection approaches would benefit from substrates with improved activity and specificity. Here, we apply a substrate-mediated selection to a peptidomimetic DNA-encoded chemical library for enrichment of molecules that can be phosphorylated by the protein tyrosine kinase, c-Src. Several substrates were identified and characterized for activity. A lead compound (SrcDEL10) showed both the ability to serve as a substrate and to promote ATP hydrolysis by the kinase. In inhibition assays, compounds displayed IC50's ranging from of 8-100 µM. NMR analysis of SrcDEL10 bound to the c-Src:ATP complex was conducted to characterize the binding mode. An ester derivative of the lead compound demonstrated cellular activity with inhibition of Src-dependent signaling in cell culture. Together, the results show the potential for substrate-mediated selections of DNA-encoded libraries to discover molecules with functions other than simple protein binding and offer a new discovery method for development of synthetic tyrosine kinase substrates.
Assuntos
Técnicas de Química Combinatória , DNA/química , Peptidomiméticos/síntese química , Bibliotecas de Moléculas Pequenas/química , Quinases da Família src/química , Trifosfato de Adenosina/química , Anticorpos Monoclonais/química , DNA/metabolismo , Genes Reporter , Humanos , Hidrólise , Cinética , Luciferases/genética , Luciferases/metabolismo , Peptidomiméticos/metabolismo , Fosforilação , Ligação Proteica , Bibliotecas de Moléculas Pequenas/metabolismo , Relação Estrutura-Atividade , Especificidade por Substrato , Quinases da Família src/metabolismoRESUMO
BACKGROUND: Overcoming systemic dormancy and initiating secondary tumor grow under unique microenvironmental conditions is a major rate-limiting step in metastatic progression. Disseminated tumor cells encounter major changes in nutrient supplies and oxidative stresses compared to the primary tumor and must demonstrate significant metabolic plasticity to adapt to specific metastatic sites. Recent studies suggest that differential utilization of pyruvate sits as a critical node in determining the organotropism of metastatic breast cancer. Pyruvate carboxylase (PC) is key enzyme that converts pyruvate into oxaloacetate for utilization in gluconeogenesis and replenishment of the TCA cycle. METHODS: Patient survival was analyzed with respect to gene copy number alterations and differential mRNA expression levels of PC. Expression of PC was analyzed in the MCF-10A, D2-HAN and the 4 T1 breast cancer progression series under in vitro and in vivo growth conditions. PC expression was depleted via shRNAs and the impact on in vitro cell growth, mammary fat pad tumor growth, and pulmonary and non-pulmonary metastasis was assessed by bioluminescent imaging. Changes in glycolytic capacity, oxygen consumption, and response to oxidative stress were quantified upon PC depletion. RESULTS: Genomic copy number increases in PC were observed in 16-30% of metastatic breast cancer patients. High expression of PC mRNA was associated with decreased patient survival in the MCTI and METABRIC patient datasets. Enhanced expression of PC was not recapitulated in breast cancer progression models when analyzed under glucose-rich in vitro culture conditions. In contrast, PC expression was dramatically enhanced upon glucose deprivation and in vivo in pulmonary metastases. Depletion of PC led to a dramatic decrease in 4 T1 pulmonary metastasis, but did not affect orthotopic primary tumor growth. Tail vein inoculations confirmed the role of PC in facilitating pulmonary, but not extrapulmonary tumor initiation. PC-depleted cells demonstrated a decrease in glycolytic capacity and oxygen consumption rates and an enhanced sensitivity to oxidative stress. CONCLUSIONS: Our studies indicate that PC is specifically required for the growth of breast cancer that has disseminated to the lungs. Overall, these findings point to the potential of targeting PC for the treatment of pulmonary metastatic breast cancer.
Assuntos
Neoplasias da Mama/genética , Neoplasias Pulmonares/genética , Piruvato Carboxilase/genética , Tropismo/genética , Animais , Neoplasias da Mama/metabolismo , Neoplasias da Mama/patologia , Linhagem Celular Tumoral , Proliferação de Células/genética , Ciclo do Ácido Cítrico/genética , Feminino , Glucose/genética , Glucose/metabolismo , Glicólise/genética , Humanos , Neoplasias Pulmonares/metabolismo , Neoplasias Pulmonares/patologia , Neoplasias Pulmonares/secundário , Estresse Oxidativo , Ácido Pirúvico/metabolismoRESUMO
Glycoproteins comprise more than half of current FDA-approved protein cancer markers, but the development of new glycoproteins as disease biomarkers has been stagnant. Here we present a pipeline to develop glycoproteins from extracellular vesicles (EVs) through integrating quantitative glycoproteomics with a novel reverse phase glycoprotein array and then apply it to identify novel biomarkers for breast cancer. EV glycoproteomics show promise in circumventing the problems plaguing current serum/plasma glycoproteomics and allowed us to identify hundreds of glycoproteins that have not been identified in blood. We identified 1,453 unique glycopeptides representing 556 glycoproteins in EVs, among which 20 were verified significantly higher in individual breast cancer patients. We further applied a novel glyco-specific reverse phase protein array to quantify a subset of the candidates. Together, this study demonstrates the great potential of this integrated pipeline for biomarker discovery.
Assuntos
Biomarcadores Tumorais/sangue , Neoplasias da Mama/diagnóstico por imagem , Vesículas Extracelulares/química , Glicoproteínas/sangue , Cromatografia Líquida , Feminino , Humanos , Espectrometria de Massas em TandemRESUMO
We previously established that overexpression of the EGF receptor (EGFR) is sufficient to induce tumor formation by otherwise nontransformed mammary epithelial cells, and that the initiation of epithelial-mesenchymal transition (EMT) is capable of increasing the invasion and metastasis of these cells. Using this breast cancer (BC) model, we find that in addition to EGF, adhesion to fibronectin (FN) activates signal transducer and activator of transcription 3 (STAT3) through EGFR-dependent and -independent mechanisms. Importantly, EMT facilitated a signaling switch from SRC-dependent EGFR:STAT3 signaling in pre-EMT cells to EGFR-independent FN:JAK2:STAT3 signaling in their post-EMT counterparts, thereby sensitizing these cells to JAK2 inhibition. Accordingly, human metastatic BC cells that failed to activate STAT3 downstream of EGFR did display robust STAT3 activity upon adhesion to FN. Furthermore, FN enhanced outgrowth in three-dimensional organotypic cultures via a mechanism that is dependent upon ß1 integrin, Janus kinase 2 (JAK2), and STAT3 but not EGFR. Collectively, our data demonstrate that matrix-initiated signaling is sufficient to drive STAT3 activation, a reaction that is facilitated by EMT during BC metastatic progression.
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Neoplasias da Mama/metabolismo , Transição Epitelial-Mesenquimal , Fibronectinas/metabolismo , Fator de Transcrição STAT3/metabolismo , Transdução de Sinais , Animais , Neoplasias da Mama/genética , Neoplasias da Mama/patologia , Adesão Celular/genética , Linhagem Celular , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Transformação Celular Neoplásica/genética , Receptores ErbB/genética , Receptores ErbB/metabolismo , Feminino , Fibronectinas/genética , Quinase 2 de Adesão Focal/genética , Quinase 2 de Adesão Focal/metabolismo , Perfilação da Expressão Gênica , Humanos , Immunoblotting , Janus Quinase 2/genética , Janus Quinase 2/metabolismo , Camundongos , Camundongos Nus , Células NIH 3T3 , Análise de Sequência com Séries de Oligonucleotídeos , Fator de Transcrição STAT3/genética , Fator de Crescimento Transformador beta1/farmacologiaRESUMO
Targeting the function of epidermal growth factor receptor (EGFR) has failed as an effective clinical option for breast cancer. Understanding the drivers of inherent resistance has been a challenge. One possible mechanism is the acquisition of stem-like properties through the process of epithelial-mesenchymal transition. A recent study by Seguin and colleagues adds to our understanding of this process by demonstrating a functional role for unligated αvß3 integrin in mediating a stem-like phenotype and facilitating resistance to EGFR-targeted therapy via enhanced downstream coupling to a KRAS:RalB:NF-κB pathway. Importantly, the identified mechanism may reveal a possible strategy for sensitizing breast cancer cells to EGFR-targeted therapies.
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Resistencia a Medicamentos Antineoplásicos , Receptores ErbB/antagonistas & inibidores , Integrina beta3/metabolismo , Neoplasias Pulmonares/tratamento farmacológico , Células-Tronco Neoplásicas/efeitos dos fármacos , Inibidores de Proteínas Quinases/uso terapêutico , Proteínas Proto-Oncogênicas/metabolismo , Proteínas ral de Ligação ao GTP/metabolismo , Proteínas ras/metabolismo , Animais , Feminino , HumanosRESUMO
INTRODUCTION: Epithelial-mesenchymal transition (EMT) and mesenchymal-epithelial transition (MET) facilitate breast cancer (BC) metastasis; however, stable molecular changes that result as a consequence of these processes remain poorly defined. Therefore, with the hope of targeting unique aspects of metastatic tumor outgrowth, we sought to identify molecular markers that could identify tumor cells that had completed the EMT:MET cycle. METHODS: An in vivo reporter system for epithelial cadherin (E-cad) expression was used to quantify its regulation in metastatic BC cells during primary and metastatic tumor growth. Exogenous addition of transforming growth factor ß1 (TGF-ß1) was used to induce EMT in an in situ model of BC. Microarray analysis was employed to examine gene expression changes in cells chronically treated with and withdrawn from TGF-ß1, thus completing one full EMT:MET cycle. Changes in fibroblast growth factor receptor type 1 (FGFR1) isoform expression were validated using PCR analyses of patient-derived tumor tissues versus matched normal tissues. FGFR1 gene expression was manipulated using short hairpin RNA depletion and cDNA rescue. Preclinical pharmacological inhibition of FGFR kinase was employed using the orally available compound BGJ-398. RESULTS: Metastatic BC cells undergo spontaneous downregulation of E-cad during primary tumor growth, and its expression subsequently returns following initiation of metastatic outgrowth. Exogenous exposure to TGF-ß1 was sufficient to drive the metastasis of an otherwise in situ model of BC and was similarly associated with a depletion and return of E-cad expression during metastatic progression. BC cells treated and withdrawn from TGF-ß stably upregulate a truncated FGFR1-ß splice variant that lacks the outermost extracellular immunoglobulin domain. Identification of this FGFR1 splice variant was verified in metastatic human BC cell lines and patient-derived tumor samples. Expression of FGFR1-ß was also dominant in a model of metastatic outgrowth where depletion of FGFR1 and pharmacologic inhibition of FGFR kinase activity both inhibited pulmonary tumor outgrowth. Highlighting the dichotomous nature of FGFR splice variants and recombinant expression of full-length FGFR1-α also blocked pulmonary tumor outgrowth. CONCLUSION: The results of our study strongly suggest that FGFR1-ß is required for the pulmonary outgrowth of metastatic BC. Moreover, FGFR1 isoform expression can be used as a predictive biomarker for therapeutic application of its kinase inhibitors.
Assuntos
Biomarcadores Tumorais/genética , Neoplasias da Mama/genética , Receptor Tipo 1 de Fator de Crescimento de Fibroblastos/genética , Fator de Crescimento Transformador beta1/farmacologia , Processamento Alternativo , Animais , Biomarcadores Tumorais/metabolismo , Neoplasias da Mama/metabolismo , Neoplasias da Mama/patologia , Caderinas/genética , Caderinas/metabolismo , Linhagem Celular , Linhagem Celular Tumoral , Células Cultivadas , Transição Epitelial-Mesenquimal/efeitos dos fármacos , Transição Epitelial-Mesenquimal/genética , Feminino , Perfilação da Expressão Gênica , Regulação Neoplásica da Expressão Gênica , Humanos , Células MCF-7 , Glândulas Mamárias Animais/citologia , Glândulas Mamárias Animais/metabolismo , Neoplasias Mamárias Experimentais/genética , Neoplasias Mamárias Experimentais/metabolismo , Neoplasias Mamárias Experimentais/patologia , Camundongos Endogâmicos BALB C , Camundongos Nus , Metástase Neoplásica , Análise de Sequência com Séries de Oligonucleotídeos , Compostos de Fenilureia/farmacologia , Isoformas de Proteínas/antagonistas & inibidores , Isoformas de Proteínas/genética , Isoformas de Proteínas/metabolismo , Pirimidinas/farmacologia , Receptor Tipo 1 de Fator de Crescimento de Fibroblastos/antagonistas & inibidores , Receptor Tipo 1 de Fator de Crescimento de Fibroblastos/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase ReversaRESUMO
Epithelial-mesenchymal transitions (EMTs) are thought to promote metastasis via downregulation of E-cadherin and upregulation of mesenchymal markers such as N-cadherin and vimentin. Contrary to this, E-cadherin is retained in many invasive carcinomas and promotes collective cell invasion. To investigate how E-cadherin regulates metastasis, we examined the highly metastatic, E-cadherin-positive murine 4T1 breast cancer model, together with the less metastatic, 4T1-related cell lines, 4T07, 168FARN, and 67NR. We found that 4T1 cells display a hybrid-E/M phenotype with co-expression of epithelial and mesenchymal markers, while 4T07, 168FARN, and 67NR display progressively more mesenchymal phenotypes in vitro that relate inversely to their metastatic capacity in vivo. Using RNA interference and constitutive expression, we demonstrate that the expression level of E-cadherin does not determine 4T1 or 4T07 cell metastatic capacity in mice. Mechanistically, 4T1 cells possess highly dynamic, unstable cell-cell junctions and can undergo collective invasion without E-cadherin downregulation. However, 4T1 orthotopic tumors in vivo also contain subregions of EMT-like loss of E-cadherin. Thus, 4T1 cells function as a model for carcinomas with a hybrid-E/M phenotype that promotes invasion and metastasis.
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Limiting cellular plasticity is of key importance for the therapeutic targeting of metastatic breast cancer (MBC). Fibroblast growth receptor (FGFR) is a critical molecule in cellular plasticity and potent inhibitors of FGFR enzymatic activity have been developed, but kinase independent functions for this receptor also contribute to MBC progression. Herein, we evaluated several FGFR inhibitors and find that while FGFR-targeted kinase inhibitors are effective at blocking ligand-induced cell growth, dormant cells persist eventually giving rise to MBC progression. To more broadly target FGFR and cellular plasticity, we examined the FGFR1 proximal promoter, and found several sequences with potential to form G-quadruplex secondary structures. Circular dichroism was used to verify formation of G-quadruplex in the FGFR1 proximal promoter. Importantly, use of the clinical G-quadruplex-stabilizing compound, CX-5461, stabilized the FGFR1 G-quadruplex structures, blocked the transcriptional activity of the FGFR1 proximal promoter, decreased FGFR1 expression, and resulted in potent inhibition of pulmonary tumor formation. Overall, our findings suggest G-quadruplex-targeted compounds could be a potential therapeutic strategy to limit the cellular plasticity of FGFR1 overexpressing MBC.
Assuntos
Neoplasias da Mama , Quadruplex G , Regiões Promotoras Genéticas , Receptor Tipo 1 de Fator de Crescimento de Fibroblastos , Quadruplex G/efeitos dos fármacos , Humanos , Neoplasias da Mama/patologia , Neoplasias da Mama/genética , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/metabolismo , Feminino , Receptor Tipo 1 de Fator de Crescimento de Fibroblastos/metabolismo , Receptor Tipo 1 de Fator de Crescimento de Fibroblastos/genética , Animais , Linhagem Celular Tumoral , Camundongos , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Metástase NeoplásicaRESUMO
Prostate cancer (PCa) is the most prevalent cancer affecting American men. Castration-resistant prostate cancer (CRPC) can emerge during hormone therapy for PCa, manifesting with elevated serum prostate-specific antigen (PSA) levels, continued disease progression, and/or metastasis to the new sites, resulting in a poor prognosis. A subset of CRPC patients shows a neuroendocrine (NE) phenotype, signifying reduced or no reliance on androgen receptor (AR) signaling and a particularly unfavorable prognosis. In this study, we incorporated computational approaches based on both gene expression profiles and protein-protein interaction (PPI) networks. We identified 500 potential marker genes, which are significantly enriched in cell cycle and neuronal processes. The top 40 candidates, collectively named as CDHu40, demonstrated superior performance in distinguishing NE prostate cancer (NEPC) and non-NEPC samples based on gene expression profiles compared to other published marker sets. Notably, some novel marker genes in CDHu40, absent in the other marker sets, have been reported to be associated with NEPC in the literature, such as DDC, FOLH1, BEX1, MAST1, and CACNA1A. Importantly, elevated CDHu40 scores derived from our predictive model showed a robust correlation with unfavorable survival outcomes in patients, indicating the potential of the CDHu40 score as a promising indicator for predicting the survival prognosis of those patients with the NE phenotype. Motif enrichment analysis on the top candidates suggests that REST and E2F6 may serve as key regulators in the NEPC progression. Significance: our study integrates gene expression variances in multiple NEPC studies and protein-protein interaction network to pinpoint a specific set of NEPC maker genes namely CDHu40. These genes and scores based on their gene expression levels effectively distinguish NEPC samples and underscore the clinical prognostic significance and potential mechanism.
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Survival of dormant, disseminated breast cancer cells contributes to tumor relapse and metastasis. Women with a body mass index greater than 35 have an increased risk of developing metastatic recurrence. Herein, we investigated the effect of diet-induced obesity (DIO) on primary tumor growth and metastatic progression using both metastatic and systemically dormant mouse models of breast cancer. This approach led to increased PT growth and pulmonary metastasis. We developed a novel protocol to induce obesity in Balb/c mice by combining dietary and hormonal interventions with a thermoneutral housing strategy. In contrast to standard housing conditions, ovariectomized Balb/c mice fed a high-fat diet under thermoneutral conditions became obese over a period of 10 weeks, resulting in a 250% gain in fat mass. Obese mice injected with the D2.OR model developed macroscopic pulmonary nodules compared with the dormant phenotype of these cells in mice fed a control diet. Analysis of the serum from obese Balb/c mice revealed increased levels of FGF2 as compared with lean mice. We demonstrate that serum from obese animals, exogenous FGF stimulation, or constitutive stimulation through autocrine and paracrine FGF2 is sufficient to break dormancy and drive pulmonary outgrowth. Blockade of FGFR signaling or specific depletion of FGFR1 prevented obesity-associated outgrowth of the D2.OR model. IMPLICATIONS: Overall, this study developed a novel DIO model that allowed for demonstration of FGF2:FGFR1 signaling as a key molecular mechanism connecting obesity to breakage of systemic tumor dormancy and metastatic progression.
Assuntos
Neoplasias da Mama , Humanos , Feminino , Animais , Camundongos , Neoplasias da Mama/genética , Fator 2 de Crescimento de Fibroblastos , Recidiva Local de Neoplasia , Obesidade/complicações , Transdução de Sinais , Camundongos Endogâmicos BALB C , Receptor Tipo 1 de Fator de Crescimento de Fibroblastos/genéticaRESUMO
Dysregulation of the ubiquitin-proteasome systems is a hallmark of various disease states including neurodegenerative diseases and cancer. Ubiquitin C-terminal hydrolase L1 (UCHL1), a deubiquitinating enzyme, is expressed primarily in the central nervous system under normal physiological conditions, however, is considered an oncogene in various cancers, including melanoma, lung, breast, and lymphoma. Thus, UCHL1 inhibitors could serve as a viable treatment strategy against these aggressive cancers. Herein, we describe a covalent fragment screen that identified the chloroacetohydrazide scaffold as a covalent UCHL1 inhibitor. Subsequent optimization provided an improved fragment with single-digit micromolar potency against UCHL1 and selectivity over the closely related UCHL3. The molecule demonstrated efficacy in cellular assays of metastasis. Additionally, we report a ligand-bound crystal structure of the most potent molecule in complex with UCHL1, providing insight into the binding mode and information for future optimization.
Assuntos
Neoplasias , Ubiquitina Tiolesterase , Humanos , Ubiquitina Tiolesterase/química , Ubiquitina Tiolesterase/metabolismo , Ubiquitina/metabolismo , Mama , Complexo de Endopeptidases do ProteassomaRESUMO
Breast cancer is the second leading cause of cancer death in women in the United States. Metastasis accounts for the death of ~90 % of these patients, yet the mechanisms underlying this event remain poorly defined. WAVE3 belongs to the WASP/WAVE family of actin-binding proteins that play essential roles in regulating cell morphology, actin polymerization, cytoskeleton remodeling, cell motility, and invasion. Accordingly, we demonstrated previously that WAVE3 promotes the acquisition of invasive and metastatic phenotypes by human breast cancers. Herein, we show that transforming growth factor-ß (TGF-ß) selectively and robustly induced the expression of WAVE3 in metastatic breast cancer cells, but not in their nonmetastatic counterparts. Moreover, the induction of WAVE3 expression in human and mouse triple-negative breast cancer cells (TNBCs) by TGF-ß likely reflects its coupling to microRNA expression via a Smad2- and ß3 integrin-dependent mechanism. We further demonstrate the requirement for WAVE3 expression in mediating the initiation of epithelial-mesenchymal transition (EMT) programs stimulated by TGF-ß. Indeed, stable depletion of WAVE3 expression in human TNBC cells prevented TGF-ß from inducing EMT programs and from stimulating the proliferation, migration, and the formation of lamellipodia in metastatic TNBC cells. Lastly, we observed WAVE3 deficiency to abrogate the outgrowth of TNBC cell organoids in 3-dimensional organotypic cultures as well as to decrease the growth and metastasis of 4T1 tumors produced in syngeneic Balb/C mice. Indeed, WAVE3 deficiency significantly reduced the presence of sarcomatoid morphologies indicative of EMT phenotypes in pulmonary TNBC tumors as compared to those detected in their parental counterparts. Collectively, these findings indicate the necessity for WAVE3 expression and activity during EMT programs stimulated by TGF-ß; they also suggest that measures capable of inactivating WAVE3 may play a role in alleviating metastasis stimulated by TGF-ß.
Assuntos
Fator de Crescimento Transformador beta/metabolismo , Neoplasias de Mama Triplo Negativas/metabolismo , Neoplasias de Mama Triplo Negativas/patologia , Família de Proteínas da Síndrome de Wiskott-Aldrich/metabolismo , Animais , Movimento Celular/genética , Proliferação de Células , Transição Epitelial-Mesenquimal , Feminino , Humanos , Integrina beta3/metabolismo , Camundongos , Camundongos Endogâmicos BALB C , Proteína Smad2/metabolismo , Regulação para Cima , Família de Proteínas da Síndrome de Wiskott-Aldrich/genética , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
Transforming growth factor-ß (TGF-ß) is a potent pleiotropic cytokine that regulates mammalian development, differentiation, and homeostasis in essentially all cell types and tissues. TGF-ß normally exerts anticancer activities by prohibiting cell proliferation and by creating cell microenvironments that inhibit cell motility, invasion, and metastasis. However, accumulating evidence indicates that the process of tumorigenesis, particularly that associated with metastatic progression, confers TGF-ß with oncogenic activities, a functional switch known as the "TGF-ß paradox." The molecular determinants governing the TGF-ß paradox are complex and represent an intense area of investigation by researchers in academic and industrial settings. Recent findings link genetic and epigenetic events in mediating the acquisition of oncogenic activity by TGF-ß, as do aberrant alterations within tumor microenvironments. These events coalesce to enable TGF-ß to direct metastatic progression via the stimulation of epithelial-mesenchymal transition (EMT), which permits carcinoma cells to abandon polarized epithelial phenotypes in favor of apolar mesenchymal-like phenotypes. Attempts to deconstruct the EMT process induced by TGF-ß have identified numerous signaling molecules, transcription factors, and microRNAs operant in mediating the initiation and resolution of this complex transdifferentiation event. In addition to its ability to enhance carcinoma cell invasion and metastasis, EMT also endows transitioned cells with stem-like properties, including the acquisition of self-renewal and tumor-initiating capabilities coupled to chemoresistance. Here, we review recent findings that delineate the pathophysiological mechanisms whereby EMT stimulated by TGF-ß promotes metastatic progression and disease recurrence in human carcinomas.