RESUMO
Extrapituitary prolactin (Prl) is produced in humans and rodents; however, little is known about its in vivo regulation or physiological function. We now report that autocrine prolactin is required for terminal mammary epithelial differentiation during pregnancy and that its production is regulated by the Pten-PI3K-Akt pathway. Conditional activation of the PI3K-Akt pathway in the mammary glands of virgin mice by either Akt1 expression or Pten deletion rapidly induced terminal mammary epithelial differentiation accompanied by the synthesis of milk despite the absence of lobuloalveolar development. Surprisingly, we found that mammary differentiation was due to the PI3K-Akt-dependent synthesis and secretion of autocrine prolactin and downstream activation of the prolactin receptor (Prlr)-Jak-Stat5 pathway. Consistent with this, Akt-induced mammary differentiation was abrogated in Prl(-/-), Prlr(-/-), and Stat5(-/-) mice. Furthermore, cells treated with conditioned medium from mammary glands in which Akt had been activated underwent rapid Stat5 phosphorylation in a manner that was blocked by inhibition of Jak2, treatment with an anti-Prl antibody, or deletion of the prolactin gene. Demonstrating a physiological requirement for autocrine prolactin, mammary glands from lactation-defective Akt1(-/-);Akt2(+/-) mice failed to express autocrine prolactin or activate Stat5 during late pregnancy despite normal levels of circulating serum prolactin and pituitary prolactin production. Our findings reveal that PI3K-Akt pathway activation is necessary and sufficient to induce autocrine prolactin production in the mammary gland, Stat5 activation, and terminal mammary epithelial differentiation, even in the absence of the normal developmental program that prepares the mammary gland for lactation. Together, these findings identify a function for autocrine prolactin during normal development and demonstrate its endogenous regulation by the PI3K-Akt pathway.
Assuntos
Regulação da Expressão Gênica , Lactação/fisiologia , Prolactina/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Fator de Transcrição STAT5/metabolismo , Animais , Comunicação Autócrina/fisiologia , Diferenciação Celular , Células Cultivadas , Regulação para Baixo , Feminino , Deleção de Genes , Lactação/genética , Glândulas Mamárias Animais/citologia , Glândulas Mamárias Animais/metabolismo , Camundongos , Proteínas do Leite/metabolismo , PTEN Fosfo-Hidrolase/genética , Gravidez , Prolactina/genética , Proteínas Proto-Oncogênicas c-akt/genéticaRESUMO
Mouse models that faithfully recapitulate human cancers are indispensable tools for studying the molecular mechanisms of tumorigenesis and testing potential anticancer therapies. In this issue of Cancer Cell, Derksen et al. describe a new mouse model that mimics multiple features of invasive lobular carcinoma of the breast (ILC), a histological subtype of human breast cancer for which no mouse model currently exists. This model further reveals an important causal link between E-cadherin loss and tumor initiation and metastasis and, in doing so, provides a valuable entrée into the tumor-suppressive functions of E-cadherin as well as the molecular underpinnings of ILC.
Assuntos
Neoplasias da Mama/patologia , Carcinoma Lobular/patologia , Modelos Animais de Doenças , Glândulas Mamárias Humanas/patologia , Animais , Neoplasias da Mama/fisiopatologia , Caderinas/genética , Caderinas/metabolismo , Carcinoma Lobular/fisiopatologia , Feminino , Humanos , Camundongos , Invasividade Neoplásica , Metástase Neoplásica , Proteína Supressora de Tumor p53/genética , Proteína Supressora de Tumor p53/metabolismoRESUMO
Fewer than 20% of triple-negative breast cancer patients experience long-term responses to mainstay chemotherapy. Resistant tumor subpopulations use alternative metabolic pathways to escape therapy, survive, and eventually recur. Here, we show in vivo, longitudinal metabolic reprogramming in residual disease and recurrence of triple-negative breast cancer xenografts with varying sensitivities to the chemotherapeutic drug paclitaxel. Optical imaging coupled with metabolomics reported an increase in non-glucose-driven mitochondrial metabolism and an increase in intratumoral metabolic heterogeneity during regression and residual disease in resistant MDA-MB-231 tumors. Conversely, sensitive HCC-1806 tumors were primarily reliant on glucose uptake and minimal changes in metabolism or heterogeneity were observed over the tumors' therapeutic life cycles. Further, day-matched resistant HCC-1806 tumors revealed a higher reliance on mitochondrial metabolism and elevated metabolic heterogeneity compared to sensitive HCC-1806 tumors. Together, metabolic flexibility, increased reliance on mitochondrial metabolism, and increased metabolic heterogeneity are defining characteristics of persistent residual disease, features that will inform the appropriate type and timing of therapies.
Assuntos
Antineoplásicos , Carcinoma Hepatocelular , Neoplasias Hepáticas , Neoplasias de Mama Triplo Negativas , Humanos , Reprogramação Metabólica , Neoplasias de Mama Triplo Negativas/tratamento farmacológico , Neoplasias de Mama Triplo Negativas/genética , Neoplasias de Mama Triplo Negativas/patologia , Carcinoma Hepatocelular/tratamento farmacológico , Neoplasias Hepáticas/tratamento farmacológico , Antineoplásicos/farmacologia , Imagem Óptica , Linhagem Celular TumoralRESUMO
Tumor recurrence following potentially curative therapy constitutes a major obstacle to achieving cures in patients with cancer. Recurrent tumors frequently arise from a population of residual cancer cells - also referred to as minimal residual disease (RD) or persister cells - that survive therapy and persist for prolonged periods prior to tumor relapse. While there has been significant recent progress in deciphering tumor-cell-intrinsic pathways that regulate residual cancer cell survival and recurrence, much less is known about how the tumor microenvironment (TME) of residual tumors impacts persister cancer cells or tumor recurrence. In this review, we highlight recent studies exploring the regulation and function of immune cells in RD and discuss therapeutic opportunities to target immune cells in residual tumors.
Assuntos
Recidiva Local de Neoplasia , Microambiente Tumoral , Humanos , Neoplasia Residual , Recidiva Local de Neoplasia/patologia , Linhagem Celular Tumoral , Sobrevivência CelularRESUMO
APOBEC mutagenesis is one of the most common endogenous sources of mutations in human cancer and is a major source of genetic intratumor heterogeneity. High levels of APOBEC mutagenesis are associated with poor prognosis and aggressive disease across diverse cancers, but the mechanistic and functional impacts of APOBEC mutagenesis on tumor evolution and therapy resistance remain relatively unexplored. To address this, we investigated the contribution of APOBEC mutagenesis to acquired therapy resistance in a model of EGFR-mutant non-small cell lung cancer. We find that inhibition of EGFR in lung cancer cells leads to a rapid and pronounced induction of APOBEC3 expression and activity. Functionally, APOBEC expression promotes the survival of drug-tolerant persister cells (DTPs) following EGFR inhibition. Constitutive expression of APOBEC3B alters the evolutionary trajectory of acquired resistance to the EGFR inhibitor gefitinib, making it more likely that resistance arises through de novo acquisition of the T790M gatekeeper mutation and squamous transdifferentiation during the DTP state. APOBEC3B expression is associated with increased expression of the squamous cell transcription factor ΔNp63 and squamous cell transdifferentiation in gefitinib-resistant cells. Knockout of ΔNp63 in gefitinibresistant cells reduces the expression of the p63 target genes IL1a/b and sensitizes these cells to the thirdgeneration EGFR inhibitor osimertinib. These results suggest that APOBEC activity promotes acquired resistance by facilitating evolution and transdifferentiation in DTPs, and suggest that approaches to target ΔNp63 in gefitinib-resistant lung cancers may have therapeutic benefit.
RESUMO
The APOBEC family of cytidine deaminases is one of the most common endogenous sources of mutations in human cancer. Genomic studies of tumors have found that APOBEC mutational signatures are enriched in the HER2 subtype of breast cancer and are associated with immunotherapy response in diverse cancer types. However, the direct consequences of APOBEC mutagenesis on the tumor immune microenvironment have not been thoroughly investigated. To address this, we developed syngeneic murine mammary tumor models with inducible expression of APOBEC3B. We found that APOBEC activity induced antitumor adaptive immune responses and CD4+ T cell-mediated, antigen-specific tumor growth inhibition. Although polyclonal APOBEC tumors had a moderate growth defect, clonal APOBEC tumors were almost completely rejected, suggesting that APOBEC-mediated genetic heterogeneity limits antitumor adaptive immune responses. Consistent with the observed immune infiltration in APOBEC tumors, APOBEC activity sensitized HER2-driven breast tumors to anti-CTLA-4 checkpoint inhibition and led to a complete response to combination anti-CTLA-4 and anti-HER2 therapy. In human breast cancers, the relationship between APOBEC mutagenesis and immunogenicity varied by breast cancer subtype and the frequency of subclonal mutations. This work provides a mechanistic basis for the sensitivity of APOBEC tumors to checkpoint inhibitors and suggests a rationale for using APOBEC mutational signatures and clonality as biomarkers predicting immunotherapy response in HER2-positive (HER2+) breast cancers.
Assuntos
Desaminases APOBEC/genética , Neoplasias da Mama/imunologia , Neoplasias da Mama/terapia , Imunoterapia/métodos , Linfócitos T/imunologia , Desaminases APOBEC/imunologia , Animais , Antígenos de Neoplasias , Neoplasias da Mama/genética , Linhagem Celular Tumoral , Feminino , Regulação Neoplásica da Expressão Gênica , Humanos , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Mutagênese/imunologia , Mutação , Microambiente Tumoral/imunologia , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
Recurrent cancer cells that evade therapy is a leading cause of death in breast cancer patients. This risk is high for women showing an overexpression of human epidermal growth factor receptor 2 (Her2). Cells that persist can rely on different substrates for energy production relative to their primary tumor counterpart. Here, we characterize metabolic reprogramming related to tumor dormancy and recurrence in a doxycycline-induced Her2+/Neu model of breast cancer with varying times to recurrence using longitudinal fluorescence microscopy. Glucose uptake (2-NBDG) and mitochondrial membrane potential (TMRE) imaging metabolically phenotype mammary tumors as they transition to regression, dormancy, and recurrence. "Fast-recurrence" tumors (time to recurrence ~55 days), transition from glycolysis to mitochondrial metabolism during regression and this persists upon recurrence. "Slow-recurrence" tumors (time to recurrence ~100 days) rely on both glycolysis and mitochondrial metabolism during recurrence. The increase in mitochondrial activity in fast-recurrence tumors is attributed to a switch from glucose to fatty acids as the primary energy source for mitochondrial metabolism. Consequently, when fast-recurrence tumors receive treatment with a fatty acid inhibitor, Etomoxir, tumors report an increase in glucose uptake and lipid synthesis during regression. Treatment with Etomoxir ultimately prolongs survival. We show that metabolic reprogramming reports on tumor recurrence characteristics, particularly at time points that are essential for actionable targets. The temporal characteristics of metabolic reprogramming will be critical in determining the use of an appropriate timing for potential therapies; namely, the notion that metabolic-targeted inhibition during regression reports long-term therapeutic benefit.
RESUMO
Whole-genome duplication (WGD) generates polyploid cells possessing more than two copies of the genome and is among the most common genetic abnormalities in cancer. The frequency of WGD increases in advanced and metastatic tumors, and WGD is associated with poor prognosis in diverse tumor types, suggesting a functional role for polyploidy in tumor progression. Experimental evidence suggests that polyploidy has both tumor-promoting and suppressing effects, but how polyploidy regulates tumor progression remains unclear. Using a genetically engineered mouse model of Her2-driven breast cancer, we explored the prevalence and consequences of whole-genome duplication during tumor growth and recurrence. While primary tumors in this model are invariably diploid, nearly 40% of recurrent tumors undergo WGD. WGD in recurrent tumors was associated with increased chromosomal instability, decreased proliferation and increased survival in stress conditions. The effects of WGD on tumor growth were dependent on tumor stage. Surprisingly, in recurrent tumor cells WGD slowed tumor formation, growth rate and opposed the process of recurrence, while WGD promoted the growth of primary tumors. These findings highlight the importance of identifying conditions that promote the growth of polyploid tumors, including the cooperating genetic mutations that allow cells to overcome the barriers to WGD tumor cell growth and proliferation.
Assuntos
Duplicação Gênica , Hibridização in Situ Fluorescente/métodos , Cariotipagem/métodos , Neoplasias Mamárias Experimentais/genética , Receptor ErbB-2/genética , Animais , Linhagem Celular Tumoral , Proliferação de Células , Instabilidade Cromossômica , Evolução Molecular , Feminino , Humanos , Camundongos , Camundongos Transgênicos , PoliploidiaRESUMO
Recurrent breast cancer presents significant challenges with aggressive phenotypes and treatment resistance. Therefore, novel therapeutics are urgently needed. Here, we report that murine recurrent breast tumor cells, when compared with primary tumor cells, are highly sensitive to ferroptosis. Discoidin Domain Receptor Tyrosine Kinase 2 (DDR2), the receptor for collagen I, is highly expressed in ferroptosis-sensitive recurrent tumor cells and human mesenchymal breast cancer cells. EMT regulators, TWIST and SNAIL, significantly induce DDR2 expression and sensitize ferroptosis in a DDR2-dependent manner. Erastin treatment induces DDR2 upregulation and phosphorylation, independent of collagen I. Furthermore, DDR2 knockdown in recurrent tumor cells reduces clonogenic proliferation. Importantly, both the ferroptosis protection and reduced clonogenic growth may be compatible with the compromised YAP/TAZ upon DDR2 inhibition. Collectively, these findings identify the important role of EMT-driven DDR2 upregulation in recurrent tumors in maintaining growth advantage but activating YAP/TAZ-mediated ferroptosis susceptibility, providing potential strategies to eradicate recurrent breast cancer cells with mesenchymal features.
Assuntos
Neoplasias da Mama/genética , Receptor com Domínio Discoidina 2/genética , Ferroptose/genética , Recidiva Local de Neoplasia/genética , Animais , Neoplasias da Mama/patologia , Proteínas de Ciclo Celular/genética , Linhagem Celular Tumoral , Movimento Celular/genética , Feminino , Fibroblastos/metabolismo , Fibroblastos/patologia , Regulação Neoplásica da Expressão Gênica/genética , Via de Sinalização Hippo , Humanos , Peptídeos e Proteínas de Sinalização Intracelular/genética , Camundongos , Recidiva Local de Neoplasia/patologia , Proteínas Nucleares/genética , Fosforilação , Piperazinas/farmacologia , Proteínas Serina-Treonina Quinases/genética , Transdução de Sinais/genética , Fatores de Transcrição da Família Snail/genética , Fatores de Transcrição/genética , Proteínas com Motivo de Ligação a PDZ com Coativador Transcricional , Proteína 1 Relacionada a Twist/genéticaRESUMO
INTRODUCTION: The Akt pathway plays a central role in regulating cell survival, proliferation and metabolism, and is one of the most commonly activated pathways in human cancer. A role for Akt in epithelial differentiation, however, has not been established. We previously reported that mice lacking Akt1, but not Akt2, exhibit a pronounced metabolic defect during late pregnancy and lactation that results from a failure to upregulate Glut1 as well as several lipid synthetic enzymes. Despite this metabolic defect, however, both Akt1-deficient and Akt2-deficient mice exhibit normal mammary epithelial differentiation and Stat5 activation. METHODS: In light of the overlapping functions of Akt family members, we considered the possibility that Akt may play an essential role in regulating mammary epithelial development that is not evident in Akt1-deficient mice due to compensation by other Akt isoforms. To address this possibility, we interbred mice bearing targeted deletions in Akt1 and Akt2 and determined the effect on mammary differentiation during pregnancy and lactation. RESULTS: Deletion of one allele of Akt2 in Akt1-deficient mice resulted in a severe defect in Stat5 activation during late pregnancy that was accompanied by a global failure of terminal mammary epithelial cell differentiation, as manifested by the near-complete loss in production of the three principal components of milk: lactose, lipid, and milk proteins. This defect was due, in part, to a failure of pregnant Akt1(-/-);Akt2(+/-) mice to upregulate the positive regulator of Prlr-Jak-Stat5 signaling, Id2, or to downregulate the negative regulators of Prlr-Jak-Stat5 signaling, caveolin-1 and Socs2. CONCLUSIONS: Our findings demonstrate an unexpected requirement for Akt in Prlr-Jak-Stat5 signaling and establish Akt as an essential central regulator of mammary epithelial differentiation and lactation.
Assuntos
Glândulas Mamárias Animais/citologia , Glândulas Mamárias Animais/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Fator de Transcrição STAT5/metabolismo , Animais , Diferenciação Celular , Proliferação de Células , Sobrevivência Celular , Feminino , Janus Quinases/metabolismo , Lactação , Camundongos , Camundongos Knockout , Proteínas do Leite/biossíntese , Técnicas de Cultura de Órgãos , Proteínas Proto-Oncogênicas c-akt/genética , Transdução de SinaisRESUMO
Dysregulated gene expression is a common feature of cancer and may underlie some aspects of tumor progression, including tumor relapse. Here, we show that recurrent mammary tumors exhibit global changes in gene expression and histone modifications and acquire dependence on the G9a histone methyltransferase. Genetic ablation of G9a delays tumor recurrence, and pharmacologic inhibition of G9a slows the growth of recurrent tumors. Mechanistically, G9a activity is required to silence pro-inflammatory cytokines, including tumor necrosis factor (TNF), through H3K9 methylation at gene promoters. G9a inhibition induces re-expression of these cytokines, leading to p53 activation and necroptosis. Recurrent tumors upregulate receptor interacting protein kinase-3 (RIPK3) expression and are dependent upon RIPK3 activity. High RIPK3 expression renders recurrent tumors sensitive to necroptosis following G9a inhibition. These findings demonstrate that G9a-mediated silencing of pro-necroptotic proteins is a critical step in tumor recurrence and suggest that G9a is a targetable dependency in recurrent breast cancer.
Assuntos
Histona-Lisina N-Metiltransferase/metabolismo , Inflamação/patologia , Neoplasias Mamárias Animais/enzimologia , Neoplasias Mamárias Animais/patologia , Recidiva Local de Neoplasia/patologia , Animais , Morte Celular , Sobrevivência Celular , Epigênese Genética , Feminino , Regulação Neoplásica da Expressão Gênica , Inativação Gênica , Histona-Lisina N-Metiltransferase/antagonistas & inibidores , Neoplasias Mamárias Animais/genética , Camundongos Nus , Necroptose , Proteína Serina-Treonina Quinases de Interação com Receptores/metabolismo , Fatores de Risco , Transcrição Gênica , Fator de Necrose Tumoral alfa/metabolismo , Proteína Supressora de Tumor p53/metabolismoRESUMO
The molecular and genetic basis of tumor recurrence is complex and poorly understood. RIPK3 is a key effector in programmed necrotic cell death and, therefore, its expression is frequently suppressed in primary tumors. In a transcriptome profiling between primary and recurrent breast tumor cells from a murine model of breast cancer recurrence, we found that RIPK3, while absent in primary tumor cells, is dramatically reexpressed in recurrent breast tumor cells by an epigenetic mechanism. Unexpectedly, we found that RIPK3 knockdown in recurrent tumor cells reduced clonogenic growth, causing cytokinesis failure, p53 stabilization, and repressed the activities of YAP/TAZ. These data uncover a surprising role of the pro-necroptotic RIPK3 kinase in enabling productive cell cycle during tumor recurrence. Remarkably, high RIPK3 expression also rendered recurrent tumor cells exquisitely dependent on extracellular cystine and undergo necroptosis upon cystine deprivation. The induction of RIPK3 in recurrent tumors unravels an unexpected mechanism that paradoxically confers on tumors both growth advantage and necrotic vulnerability, providing potential strategies to eradicate recurrent tumors.
Assuntos
Cistina/metabolismo , Neoplasias Mamárias Animais/patologia , Recidiva Local de Neoplasia/patologia , Proteína Serina-Treonina Quinases de Interação com Receptores/genética , Regulação para Cima/genética , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Animais , Proliferação de Células/efeitos dos fármacos , Epigênese Genética/efeitos dos fármacos , Feminino , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Neoplasias Mamárias Animais/genética , Mitose/efeitos dos fármacos , Recidiva Local de Neoplasia/genética , Piperazinas/farmacologia , Proteína Serina-Treonina Quinases de Interação com Receptores/metabolismo , Transdução de Sinais/efeitos dos fármacos , Transcriptoma/genética , Ensaio Tumoral de Célula-Tronco , Proteína Supressora de Tumor p53/metabolismo , Regulação para Cima/efeitos dos fármacos , Proteínas de Sinalização YAPRESUMO
The survival and recurrence of dormant tumour cells following therapy is a leading cause of death in cancer patients. The metabolic properties of these cells are likely distinct from those of rapidly growing tumours. Here we show that Her2 down-regulation in breast cancer cells promotes changes in cellular metabolism, culminating in oxidative stress and compensatory upregulation of the antioxidant transcription factor, NRF2. NRF2 is activated during dormancy and in recurrent tumours in animal models and breast cancer patients with poor prognosis. Constitutive activation of NRF2 accelerates recurrence, while suppression of NRF2 impairs it. In recurrent tumours, NRF2 signalling induces a transcriptional metabolic reprogramming to re-establish redox homeostasis and upregulate de novo nucleotide synthesis. The NRF2-driven metabolic state renders recurrent tumour cells sensitive to glutaminase inhibition, which prevents reactivation of dormant tumour cells in vitro, suggesting that NRF2-high dormant and recurrent tumours may be targeted. These data provide evidence that NRF2-driven metabolic reprogramming promotes the recurrence of dormant breast cancer.
Assuntos
Fator 2 Relacionado a NF-E2/metabolismo , Nucleotídeos/metabolismo , Animais , Neoplasias da Mama/metabolismo , Neoplasias da Mama/patologia , Morte Celular , Linhagem Celular Tumoral , Regulação para Baixo , Feminino , Homeostase , Humanos , Camundongos , Recidiva Local de Neoplasia , Oxirredução , Espécies Reativas de Oxigênio/metabolismo , Receptor ErbB-2/metabolismo , Transdução de Sinais , Transcrição GênicaRESUMO
The survival and recurrence of residual tumor cells following therapy constitutes one of the biggest obstacles to obtaining cures in breast cancer, but it remains unclear how the clonal composition of tumors changes during relapse. We use cellular barcoding to monitor clonal dynamics during tumor recurrence in vivo. We find that clonal diversity decreases during tumor regression, residual disease, and recurrence. The recurrence of dormant residual cells follows several distinct routes. Approximately half of the recurrent tumors exhibit clonal dominance with a small number of subclones comprising the vast majority of the tumor; these clonal recurrences are frequently dependent upon Met gene amplification. A second group of recurrent tumors comprises thousands of subclones, has a clonal architecture similar to primary tumors, and is dependent upon the Jak/Stat pathway. Thus the regrowth of dormant tumors proceeds via multiple routes, producing recurrent tumors with distinct clonal composition, genetic alterations, and drug sensitivities.
Assuntos
Neoplasias da Mama/patologia , Regulação Neoplásica da Expressão Gênica , Recidiva Local de Neoplasia/genética , Recidiva Local de Neoplasia/patologia , Animais , Linhagem Celular Tumoral , Crizotinibe/farmacologia , Doxiciclina/farmacologia , Transição Epitelial-Mesenquimal/genética , Feminino , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Neoplasias Pulmonares/patologia , Neoplasias Pulmonares/secundário , Camundongos Nus , Recidiva Local de Neoplasia/tratamento farmacológico , Proteínas Proto-Oncogênicas c-met/antagonistas & inibidores , Proteínas Proto-Oncogênicas c-met/genética , Receptor ErbB-2/genética , Análise de Célula Única , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
Over half of breast-cancer-related deaths are due to recurrence 5 or more years after initial diagnosis and treatment. This latency suggests that a population of residual tumor cells can survive treatment and persist in a dormant state for many years. The role of the microenvironment in regulating the survival and proliferation of residual cells following therapy remains unexplored. Using a conditional mouse model for Her2-driven breast cancer, we identify interactions between residual tumor cells and their microenvironment as critical for promoting tumor recurrence. Her2 downregulation leads to an inflammatory program driven by TNFα/NFκB signaling, which promotes immune cell infiltration in regressing and residual tumors. The cytokine CCL5 is elevated following Her2 downregulation and remains high in residual tumors. CCL5 promotes tumor recurrence by recruiting CCR5-expressing macrophages, which may contribute to collagen deposition in residual tumors. Blocking this TNFα-CCL5-macrophage axis may be efficacious in preventing breast cancer recurrence.
Assuntos
Neoplasias da Mama/fisiopatologia , Quimiocina CCL5/metabolismo , Animais , Modelos Animais de Doenças , Macrófagos/imunologia , Camundongos , Neoplasia Residual/fisiopatologia , Receptor ErbB-2/metabolismo , Recidiva , Fator de Necrose Tumoral alfa/metabolismoRESUMO
With the large number of women diagnosed and treated for breast cancer each year, the importance of studying recurrence has become evident due to most deaths from breast cancer resulting from tumor recurrence following therapy. To mitigate this, cellular and molecular pathways used by residual disease prior to recurrence must be studied. An altered metabolism has long been considered a hallmark of cancer, and several recent studies have gone further to report metabolic dysfunction and alterations as key to understanding the underlying behavior of dormant and recurrent cancer cells. Our group has used two probes, 2-[N-(7-nitrobenz-2-oxa-1, 3-diaxol-4-yl) amino]-2-deoxyglucose (2-NBDG) and tetramethyl rhodamine ethyl ester (TMRE), to image glucose uptake and mitochondrial membrane potential, respectively, to report changes in metabolism between primary tumors, regression, residual disease, and after regrowth in genetically engineered mouse (GEM)-derived mammospheres. Imaging revealed unique metabolic phenotypes across the stages of tumor development. Although primary mammospheres overexpressing Her2 maintained increased glucose uptake ("Warburg effect"), after Her2 downregulation, during regression and residual disease, mammospheres appeared to switch to oxidative phosphorylation. Interestingly, in mammospheres where Her2 overexpression was turned back on to model recurrence, glucose uptake was lowest, indicating a potential change in substrate preference following the reactivation of Her2, reeliciting growth. Our findings highlight the importance of imaging metabolic adaptions to gain insight into the fundamental behaviors of residual and recurrent disease. IMPLICATIONS: This study demonstrates these functional fluorescent probes' ability to report metabolic adaptations during primary tumor growth, regression, residual disease, and regrowth in Her2 breast tumors.
Assuntos
Neoplasias da Mama/genética , Glucose/metabolismo , Recidiva Local de Neoplasia/genética , Receptor ErbB-2/genética , 4-Cloro-7-nitrobenzofurazano/análogos & derivados , 4-Cloro-7-nitrobenzofurazano/farmacologia , Animais , Animais Geneticamente Modificados , Neoplasias da Mama/metabolismo , Neoplasias da Mama/patologia , Linhagem Celular Tumoral , Proliferação de Células/genética , Desoxiglucose/análogos & derivados , Desoxiglucose/farmacologia , Feminino , Regulação Neoplásica da Expressão Gênica , Glucose/genética , Humanos , Glândulas Mamárias Animais/metabolismo , Glândulas Mamárias Animais/patologia , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Recidiva Local de Neoplasia/metabolismo , Compostos Organometálicos/farmacologia , FenótipoRESUMO
Somatic mutations in the epidermal growth factor receptor (EGFR) occur frequently in lung cancer and confer sensitivity to EGFR kinase inhibitors gefitinib and erlotinib. These mutations, which occur in the kinase domain of the protein, also render EGFR constitutively active and transforming. Signal transducers and activators of transcription 3 (STAT3) transduces signals from a number of oncogenic tyrosine kinases and contributes to a wide spectrum of human malignancies. Here, we show that STAT3 is activated by mutant EGFRs and is necessary for its downstream phenotypic effects. Inhibiting STAT3 function in fibroblasts abrogates transformation by mutant EGFR. In non-small-cell lung cancer cells, STAT3 activity is regulated by EGFR through modulation of STAT3 serine phosphorylation. Inhibiting STAT3 function increases apoptosis of these cells, suggesting that STAT3 is necessary for their survival. Finally, a group of genes constituting a STAT3 signature is enriched in lung tumors with EGFR mutations. Thus, STAT3 is a critical mediator of the oncogenic effects of somatic EGFR mutations and targeting STAT3 may be an effective strategy for treating tumors characterized by these mutations.
Assuntos
Carcinoma Pulmonar de Células não Pequenas/genética , Receptores ErbB/genética , Neoplasias Pulmonares/genética , Fator de Transcrição STAT3/fisiologia , Animais , Carcinoma Pulmonar de Células não Pequenas/metabolismo , Carcinoma Pulmonar de Células não Pequenas/patologia , Linhagem Celular Tumoral , Sobrevivência Celular/fisiologia , Transformação Celular Neoplásica/genética , Transformação Celular Neoplásica/metabolismo , Receptores ErbB/biossíntese , Receptores ErbB/metabolismo , Humanos , Neoplasias Pulmonares/metabolismo , Neoplasias Pulmonares/patologia , Camundongos , Mutação , Células NIH 3T3 , Fosforilação , Fator de Transcrição STAT3/antagonistas & inibidores , Fator de Transcrição STAT3/genética , Fator de Transcrição STAT3/metabolismoRESUMO
Tumor recurrence is a leading cause of death and is thought to arise from a population of residual cells that survive treatment. These residual cancer cells can persist, locally or at distant sites, for years or decades. Therefore, understanding the pathways that regulate residual cancer cell survival may suggest opportunities for targeting these cells to prevent recurrence. Previously, it was observed that the proapoptotic protein (PAWR/Par-4) negatively regulates residual cell survival and recurrence in mice and humans. However, the mechanistic underpinnings on how Par-4 expression is regulated are unclear. Here, it is demonstrated that Par-4 is transcriptionally upregulated following treatment with multiple drugs targeting the PI3K-Akt-mTOR signaling pathway, and identify the Forkhead family of transcription factors as mediators of this upregulation. Mechanistically, Foxo3a directly binds to the Par-4 promoter and activates its transcription following inhibition of the PI3K-Akt pathway. This Foxo-dependent Par-4 upregulation limits the long-term survival of residual cells following treatment with therapeutics that target the PI3K-Akt pathway. Taken together, these results indicate that residual breast cancer tumor cell survival and recurrence requires circumventing Foxo-driven Par-4 upregulation and suggest that approaches to enforce Par-4 expression may prevent residual cell survival and recurrence. Mol Cancer Res; 16(4); 599-609. ©2018 AACR.
Assuntos
Proteínas Reguladoras de Apoptose/genética , Neoplasias da Mama/metabolismo , Fatores de Transcrição Forkhead/metabolismo , Lapatinib/farmacologia , Recidiva Local de Neoplasia/metabolismo , Regulação para Cima , Proteínas Reguladoras de Apoptose/metabolismo , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Feminino , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , Células MCF-7 , Fosfatidilinositol 3-Quinases/metabolismo , Regiões Promotoras Genéticas , Proteínas Proto-Oncogênicas c-akt/metabolismo , Transdução de Sinais/efeitos dos fármacosRESUMO
Tumor relapse is the leading cause of death in breast cancer, largely due to the fact that recurrent tumors are frequently resistant to chemotherapy. We previously reported that downregulation of the proapoptotic protein Par-4 promotes tumor recurrence in genetically engineered mouse models of breast cancer recurrence. In the present study, we examined the mechanism and functional significance of Par-4 downregulation in recurrent tumors. We found that epithelial-to-mesenchymal transition (EMT) promotes epigenetic silencing of Par-4 in recurrent tumors. Par-4 silencing proceeded through binding of the EMT transcription factor Twist to the Par-4 promoter, where Twist induced a unique bivalent chromatin domain. This bivalent configuration conferred plasticity at the Par-4 promoter, and Par-4 silencing could be reversed with pharmacologic inhibitors of Ezh2 and HDAC1/2. Using an epigenome editing approach to reexpress Par-4 by specifically reversing the histone modifications found in recurrent tumors, we found that Par-4 reexpression sensitized recurrent tumors to chemotherapy in vitro and in vivo. Upon reexpression, Par-4 bound to the protein phosphatase PP1, caused widespread changes in phosphorylation of cytoskeletal proteins, and cooperated with microtubule-targeting drugs to induce mitotic defects. These results identify Twist-induced epigenetic silencing of Par-4 as a targetable axis that promotes chemoresistance in recurrent breast cancer.
Assuntos
Proteínas Reguladoras de Apoptose/biossíntese , Neoplasias da Mama/metabolismo , Resistencia a Medicamentos Antineoplásicos , Transição Epitelial-Mesenquimal , Regulação Neoplásica da Expressão Gênica , Inativação Gênica , Recidiva Local de Neoplasia/metabolismo , Proteínas Supressoras de Tumor/biossíntese , Animais , Antineoplásicos/farmacologia , Proteínas Reguladoras de Apoptose/genética , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/genética , Neoplasias da Mama/patologia , Linhagem Celular Tumoral , Proteína Potenciadora do Homólogo 2 de Zeste/genética , Proteína Potenciadora do Homólogo 2 de Zeste/metabolismo , Feminino , Histona Desacetilase 1/genética , Histona Desacetilase 1/metabolismo , Histona Desacetilase 2/genética , Histona Desacetilase 2/metabolismo , Humanos , Camundongos , Camundongos Nus , Recidiva Local de Neoplasia/tratamento farmacológico , Recidiva Local de Neoplasia/genética , Recidiva Local de Neoplasia/patologia , Proteínas Nucleares/genética , Proteínas Nucleares/metabolismo , Proteínas Supressoras de Tumor/genética , Proteína 1 Relacionada a Twist/genética , Proteína 1 Relacionada a Twist/metabolismoRESUMO
Signal transducer and activator of transcription 3 (STAT3) is a transcription factor that is activated in diverse human tumors and may play a direct role in malignant transformation. However, the full complement of target genes that STAT3 regulates to promote oncogenesis is not known. We created a system to express a constitutively active form of STAT3, STAT3-C, in mouse fibroblasts and used it to identify STAT3 targets. We showed that a subset of these targets, which include transcription factors regulating cell growth, survival, and differentiation, are coexpressed in a range of human tumors. Using immunohistochemical staining of tissue microarrays, we showed that these targets are enriched in breast and prostate tumors harboring activated STAT3. Finally, we showed that STAT3 is required for the expression of these genes in a breast cancer cell line. Taken together, these results identify a cohort of STAT3 targets that may mediate its role in oncogenesis.