RESUMO
Metastasis is a complex and poorly understood process. In pancreatic cancer, loss of the transforming growth factor (TGF)-ß/BMP effector SMAD4 is correlated with changes in altered histopathological transitions, metastatic disease, and poor prognosis. In this study, we use isogenic cancer cell lines to identify SMAD4 regulated genes that contribute to the development of metastatic colonization. We perform an in vivo screen identifying FOSL1 as both a SMAD4 target and sufficient to drive colonization to the lung. The targeting of these genes early in treatment may provide a therapeutic benefit.
Assuntos
Regulação Neoplásica da Expressão Gênica , Neoplasias Pancreáticas/genética , Neoplasias Pancreáticas/patologia , Proteínas Proto-Oncogênicas c-fos/genética , Proteína Smad4/metabolismo , Adenocarcinoma/genética , Adenocarcinoma/patologia , Animais , Carcinoma Ductal Pancreático/genética , Carcinoma Ductal Pancreático/patologia , Linhagem Celular Tumoral , Proliferação de Células/genética , Elementos Facilitadores Genéticos/genética , Humanos , Camundongos , Metástase Neoplásica , Proteínas Proto-Oncogênicas c-fos/metabolismo , Neoplasias PancreáticasRESUMO
The mechanistic contributions of cancer-associated fibroblasts (CAFs) in breast cancer progression remain to be fully understood. While altered glucose metabolism in CAFs could fuel cancer cells, how such metabolic reprogramming emerges and is sustained needs further investigation. Studying fibroblasts isolated from patients with benign breast tissues and breast cancer, in conjunction with multiple animal models, we demonstrate that CAFs exhibit a metabolic shift toward lactate and pyruvate production and fuel biosynthetic pathways of cancer cells. The depletion or suppression of the lactate production of CAFs alter the tumor metabolic profile and impede tumor growth. The glycolytic phenotype of the CAFs is in part sustained through epigenetic reprogramming of HIF-1α and glycolytic enzymes. Hypoxia induces epigenetic reprogramming of normal fibroblasts, resulting in a pro-glycolytic, CAF-like transcriptome. Our findings suggest that the glucose metabolism of CAFs evolves during tumor progression, and their breast cancer-promoting phenotype is partly mediated by oxygen-dependent epigenetic modifications.
Assuntos
Neoplasias da Mama/patologia , Fibroblastos Associados a Câncer/metabolismo , Epigenômica , Glucose/metabolismo , Actinas/genética , Actinas/metabolismo , Animais , Neoplasias da Mama/metabolismo , Fibroblastos Associados a Câncer/citologia , Linhagem Celular Tumoral , Feminino , Glicólise , Humanos , Subunidade alfa do Fator 1 Induzível por Hipóxia/genética , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Ácido Láctico/metabolismo , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Transgênicos , Transportadores de Ácidos Monocarboxílicos/antagonistas & inibidores , Transportadores de Ácidos Monocarboxílicos/genética , Transportadores de Ácidos Monocarboxílicos/metabolismo , Piruvato Desidrogenase Quinase de Transferência de Acetil/antagonistas & inibidores , Piruvato Desidrogenase Quinase de Transferência de Acetil/genética , Piruvato Desidrogenase Quinase de Transferência de Acetil/metabolismo , Ácido Pirúvico/metabolismo , Interferência de RNA , RNA Interferente Pequeno/metabolismo , Simportadores/antagonistas & inibidores , Simportadores/genética , Simportadores/metabolismoRESUMO
Exosomes are secreted by all cell types and contain proteins and nucleic acids. Here, we report that breast cancer associated exosomes contain microRNAs (miRNAs) associated with the RISC-Loading Complex (RLC) and display cell-independent capacity to process precursor microRNAs (pre-miRNAs) into mature miRNAs. Pre-miRNAs, along with Dicer, AGO2, and TRBP, are present in exosomes of cancer cells. CD43 mediates the accumulation of Dicer specifically in cancer exosomes. Cancer exosomes mediate an efficient and rapid silencing of mRNAs to reprogram the target cell transcriptome. Exosomes derived from cells and sera of patients with breast cancer instigate nontumorigenic epithelial cells to form tumors in a Dicer-dependent manner. These findings offer opportunities for the development of exosomes based biomarkers and therapies.
Assuntos
Neoplasias da Mama/metabolismo , Carcinogênese/metabolismo , Exossomos/fisiologia , MicroRNAs/biossíntese , Animais , Proteínas Argonautas/metabolismo , Neoplasias da Mama/genética , Carboxipeptidases/metabolismo , Estudos de Casos e Controles , RNA Helicases DEAD-box/metabolismo , Feminino , Regulação Neoplásica da Expressão Gênica , Humanos , Células MCF-7 , Camundongos , Processamento Pós-Transcricional do RNA , Proteínas de Ligação a RNA/metabolismo , Ribonuclease III/metabolismo , TranscriptomaRESUMO
Cancer cells can divert metabolites into anabolic pathways to support their rapid proliferation and to accumulate the cellular building blocks required for tumour growth. However, the specific bioenergetic profile of invasive and metastatic cancer cells is unknown. Here we report that migratory/invasive cancer cells specifically favour mitochondrial respiration and increased ATP production. Invasive cancer cells use the transcription coactivator peroxisome proliferator-activated receptor gamma, coactivator 1 alpha (PPARGC1A, also known as PGC-1α) to enhance oxidative phosphorylation, mitochondrial biogenesis and the oxygen consumption rate. Clinical analysis of human invasive breast cancers revealed a strong correlation between PGC-1α expression in invasive cancer cells and the formation of distant metastases. Silencing of PGC-1α in cancer cells suspended their invasive potential and attenuated metastasis without affecting proliferation, primary tumour growth or the epithelial-to-mesenchymal program. Inherent genetics of cancer cells can determine the transcriptome framework associated with invasion and metastasis, and mitochondrial biogenesis and respiration induced by PGC-1α are also essential for functional motility of cancer cells and metastasis.
Assuntos
Movimento Celular , Mitocôndrias/metabolismo , Fosforilação Oxidativa , Fatores de Transcrição/metabolismo , Animais , Western Blotting , Neoplasias da Mama/genética , Neoplasias da Mama/metabolismo , Neoplasias da Mama/patologia , Linhagem Celular Tumoral , Feminino , Perfilação da Expressão Gênica , Regulação Neoplásica da Expressão Gênica , Humanos , Imuno-Histoquímica , Masculino , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Camundongos Nus , Microscopia Eletrônica de Transmissão , Pessoa de Meia-Idade , Invasividade Neoplásica , Metástase Neoplásica , Neoplasias/genética , Neoplasias/metabolismo , Neoplasias/ultraestrutura , Consumo de Oxigênio , Coativador 1-alfa do Receptor gama Ativado por Proliferador de Peroxissomo , Interferência de RNA , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Fatores de Transcrição/genéticaRESUMO
The functional role of pericytes in cancer progression remains unknown. Clinical studies suggest that low numbers of vessel-associated pericytes correlated with a drop in overall survival of patients with invasive breast cancer. Using genetic mouse models or pharmacological inhibitors, pericyte depletion suppressed tumor growth but enhanced metastasis. Pericyte depletion was further associated with increased hypoxia, epithelial-to-mesenchymal transition (EMT), and Met receptor activation. Silencing of Twist or use of a Met inhibitor suppressed hypoxia and EMT/Met-driven metastasis. In addition, poor pericyte coverage coupled with high Met expression in cancer cells speculates the worst prognosis for patients with invasive breast cancer. Collectively, our study suggests that pericytes within the primary tumor microenvironment likely serve as important gatekeepers against cancer progression and metastasis.
Assuntos
Transição Epitelial-Mesenquimal , Metástase Neoplásica , Pericitos/fisiologia , Proteínas Proto-Oncogênicas c-met/fisiologia , Animais , Antineoplásicos/farmacologia , Benzamidas , Benzenossulfonatos/farmacologia , Neoplasias da Mama/patologia , Hipóxia Celular , Linhagem Celular Tumoral , Crizotinibe , Feminino , Humanos , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Subunidade alfa do Fator 1 Induzível por Hipóxia/fisiologia , Mesilato de Imatinib , Indóis/farmacologia , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Niacinamida/análogos & derivados , Pericitos/patologia , Compostos de Fenilureia , Piperazinas/farmacologia , Piperidinas/farmacologia , Inibidores de Proteínas Quinases/farmacologia , Proteínas Proto-Oncogênicas c-met/antagonistas & inibidores , Proteínas Proto-Oncogênicas c-met/metabolismo , Pirazóis , Piridinas/farmacologia , Pirimidinas/farmacologia , Pirróis/farmacologia , Transdução de Sinais , Sorafenibe , Sunitinibe , Células Tumorais CultivadasRESUMO
Increased numbers of S100A4(+) cells are associated with poor prognosis in patients who have cancer. Although the metastatic capabilities of S100A4(+) cancer cells have been examined, the functional role of S100A4(+) stromal cells in metastasis is largely unknown. To study the contribution of S100A4(+) stromal cells in metastasis, we used transgenic mice that express viral thymidine kinase under control of the S100A4 promoter to specifically ablate S100A4(+) stromal cells. Depletion of S100A4(+) stromal cells significantly reduced metastatic colonization without affecting primary tumor growth. Multiple bone marrow transplantation studies demonstrated that these effects of S100A4(+) stromal cells are attributable to local non-bone marrow-derived S100A4(+) cells, which are likely fibroblasts in this setting. Reduction in metastasis due to the loss of S100A4(+) fibroblasts correlated with a concomitant decrease in the expression of several ECM molecules and growth factors, particularly Tenascin-C and VEGF-A. The functional importance of stromal Tenascin-C and S100A4(+) fibroblast-derived VEGF-A in metastasis was established by examining Tenascin-C null mice and transgenic mice expressing Cre recombinase under control of the S100A4 promoter crossed with mice carrying VEGF-A alleles flanked by loxP sites, which exhibited a significant decrease in metastatic colonization without effects on primary tumor growth. In particular, S100A4(+) fibroblast-derived VEGF-A plays an important role in the establishment of an angiogenic microenvironment at the metastatic site to facilitate colonization, whereas stromal Tenascin-C may provide protection from apoptosis. Our study demonstrates a crucial role for local S100A4(+) fibroblasts in providing the permissive "soil" for metastatic colonization, a challenging step in the metastatic cascade.