RESUMEN
The epithelial-mesenchymal transition (EMT) is an embryonic transdifferentiation process consisting of conversion of polarized epithelial cells to motile mesenchymal ones. EMT-inducing transcription factors are aberrantly expressed in multiple tumor types and are known to favor the metastatic dissemination process. Supporting oncogenic activity within primary lesions, the TWIST and ZEB proteins can prevent cells from undergoing oncogene-induced senescence and apoptosis by abolishing both p53- and RB-dependent pathways. Here we show that they also downregulate PP2A phosphatase activity and efficiently cooperate with an oncogenic version of H-RAS in malignant transformation of human mammary epithelial cells. Thus, by down-regulating crucial tumor suppressor functions, EMT inducers make cells particularly prone to malignant conversion. Importantly, by analyzing transformed cells generated in vitro and by characterizing novel transgenic mouse models, we further demonstrate that cooperation between an EMT inducer and an active form of RAS is sufficient to trigger transformation of mammary epithelial cells into malignant cells exhibiting all the characteristic features of claudin-low tumors, including low expression of tight and adherens junction genes, EMT traits, and stem cell-like characteristics. Claudin-low tumors are believed to be the most primitive breast malignancies, having arisen through transformation of an early epithelial precursor with inherent stemness properties and metaplastic features. Challenging this prevailing view, we propose that these aggressive tumors arise from cells committed to luminal differentiation, through a process driven by EMT inducers and combining malignant transformation and transdifferentiation.
Asunto(s)
Neoplasias de la Mama , Transformación Celular Neoplásica , Claudinas , Transición Epitelial-Mesenquimal , Glándulas Mamarias Humanas/metabolismo , Proteína Fosfatasa 2 , Proteína 1 Relacionada con Twist/genética , Animales , Neoplasias de la Mama/genética , Neoplasias de la Mama/metabolismo , Diferenciación Celular , Línea Celular , Transformación Celular Neoplásica/genética , Transformación Celular Neoplásica/metabolismo , Claudinas/genética , Claudinas/metabolismo , Células Epiteliales/citología , Células Epiteliales/metabolismo , Transición Epitelial-Mesenquimal/genética , Femenino , Regulación Neoplásica de la Expresión Génica , Genes ras , Proteínas de Homeodominio/genética , Proteínas de Homeodominio/metabolismo , Humanos , Glándulas Mamarias Animales/citología , Glándulas Mamarias Animales/metabolismo , Glándulas Mamarias Humanas/citología , Ratones , Ratones Transgénicos , Proteína Fosfatasa 2/antagonistas & inhibidores , Proteína Fosfatasa 2/metabolismo , Proteína de Retinoblastoma/metabolismo , Telomerasa/metabolismo , Factores de Transcripción/genética , Factores de Transcripción/metabolismo , Proteína p53 Supresora de Tumor/metabolismo , Proteína 1 Relacionada con Twist/metabolismo , Homeobox 1 de Unión a la E-Box con Dedos de ZincRESUMEN
Lysyl oxidase (LOX) is a secreted copper-dependent amine oxidase whose primary function is to drive collagen crosslinking and extracellular matrix stiffness. LOX in colorectal cancer synergizes with hypoxia-inducible factor-1 (HIF-1) to promote tumor progression. Here we investigated whether LOX/HIF1 endows colorectal cancer cells with full competence for aggressive colonization in bone. We show that a high LOX expression in primary tumors from patients with colorectal cancer was associated with poor clinical outcome, irrespective of HIF-1 In addition, LOX was expressed by tumor cells in the bone marrow from colorectal cancer patients with bone metastases. In vivo experimental studies show that LOX overexpression in colorectal cancer cells or systemic delivery of the conditioned medium from LOX-overexpressing colorectal cancer cells promoted tumor cell dissemination in the bone marrow and enhanced osteolytic lesion formation, irrespective of HIF-1 Conversely, silencing or pharmacologic inhibition of LOX activity blocked dissemination of colorectal cancer cells in the bone marrow and tumor-driven osteolytic lesion formation. In vitro, tumor-secreted LOX supported the attachment and survival of colorectal cancer cells to and in the bone matrix, and inhibited osteoblast differentiation. LOX overexpression in colorectal cancer cells also induced a robust production of IL6. In turn, both LOX and IL6 were acting in concert to promote RANKL-dependent osteoclast differentiation, thereby creating an imbalance between bone resorption and bone formation. Collectively, our findings show that LOX supports colorectal cancer cell dissemination in the bone marrow and they reveal a novel mechanism through which LOX-driven IL6 production by colorectal cancer cells impairs bone homeostasis. Cancer Res; 77(2); 268-78. ©2016 AACR.
Asunto(s)
Neoplasias Óseas/secundario , Neoplasias Colorrectales/enzimología , Neoplasias Colorrectales/secundario , Invasividad Neoplásica/patología , Proteína-Lisina 6-Oxidasa/metabolismo , Animales , Western Blotting , Huesos/metabolismo , Huesos/patología , Línea Celular Tumoral , Ensayo de Inmunoadsorción Enzimática , Femenino , Xenoinjertos , Humanos , Inmunohistoquímica , Interleucina-6/metabolismo , Ratones , Ratones Endogámicos BALB C , Ratones Desnudos , Reacción en Cadena en Tiempo Real de la PolimerasaRESUMEN
Basal-like breast cancers (BLBCs) exhibit hyperactivation of the phosphoinositide 3-kinase (PI3K) signaling pathway because of the frequent mutational activation of the PIK3CA catalytic subunit and the genetic loss of its negative regulators PTEN (phosphatase and tensin homolog) and INPP4B (inositol polyphosphate-4-phosphatase type II). However, PI3K inhibitors have had limited clinical efficacy in BLBC management because of compensatory amplification of PI3K downstream signaling loops. Therefore, identification of critical PI3K mediators is paramount to the development of effective BLBC therapeutics. Using transcriptomic analysis of activated PIK3CA-expressing BLBC cells, we identified the gene encoding the humoral pattern recognition molecule pentraxin-3 (PTX3) as a critical target of oncogenic PI3K signaling. We found that PTX3 abundance is stimulated, in part, through AKT- and nuclear factor κB (NF-κB)-dependent pathways and that presence of PTX3 is necessary for PI3K-induced stem cell-like traits. We further showed that PTX3 expression is greater in tumor samples from patients with BLBC and that it is prognostic of poor patient survival. Our results thus reveal PTX3 as a newly identified PI3K-regulated biomarker and a potential therapeutic target in BLBC.
Asunto(s)
Biomarcadores de Tumor/metabolismo , Neoplasias de la Mama/metabolismo , Proteína C-Reactiva/metabolismo , Fosfatidilinositol 3-Quinasa Clase I/metabolismo , Células Madre Neoplásicas/metabolismo , Componente Amiloide P Sérico/metabolismo , Transducción de Señal , Biomarcadores de Tumor/genética , Neoplasias de la Mama/genética , Neoplasias de la Mama/patología , Neoplasias de la Mama/terapia , Proteína C-Reactiva/genética , Línea Celular Tumoral , Fosfatidilinositol 3-Quinasa Clase I/genética , Femenino , Humanos , Células Madre Neoplásicas/patología , Monoéster Fosfórico Hidrolasas/genética , Monoéster Fosfórico Hidrolasas/metabolismo , Proteínas Proto-Oncogénicas c-akt/genética , Proteínas Proto-Oncogénicas c-akt/metabolismo , Sitios de Carácter Cuantitativo , Componente Amiloide P Sérico/genéticaRESUMEN
A simple, yet powerful magnetic-levitation-based device is reported for real-time, label-free separation, as well as high-resolution monitoring of cell populations based on their unique magnetic and density signatures. This method allows a wide variety of cellular processes to be studied, accompanied by transient or permanent changes in cells' fundamental characteristics as a biological material.
Asunto(s)
Citometría de Imagen/instrumentación , Fenómenos Magnéticos , Eritrocitos/citología , Humanos , Microscopía Fluorescente , Factores de TiempoRESUMEN
The proinflammatory cytokine Interleukin 17A (hereafter named IL-17A) or IL-17A producing cells are elevated in breast tumors environment and correlate with poor prognosis. Increased IL-17A is associated with ER(-) or triple negative tumors and reduced Disease Free Survival. However, the pathophysiological role of IL-17A in breast cancer remains unclear although several studies suggested its involvement in cancer cell dissemination. Here we demonstrated that a subset of breast tumors is infiltrated with IL-17A-producing cells. Increased IL-17A seems mainly associated to ER(-) and triple negative/basal-like tumors. Isolation of tumor infiltrating T lymphocytes (TILs) from breast cancer biopsies revealed that these cells secreted significant amounts of IL-17A. We further established that recombinant IL-17A recruits the MAPK pathway by upregulating phosphorylated ERK1/2 in human breast cancer cell lines thereby promoting proliferation and resistance to conventional chemotherapeutic agents such as docetaxel. We also confirmed here that recombinant IL-17A stimulates migration and invasion of breast cancer cells as previously reported. Importantly, TILs also induced tumor cell proliferation, chemoresistance and migration and treatment with IL-17A-neutralizing antibodies abrogated these effects. Altogether these results demonstrated the pathophysiological role of IL-17A-producing cell infiltrate in a subset of breast cancers. Therefore, IL-17A appears as potential therapeutic target for breast cancer.
Asunto(s)
Neoplasias de la Mama/inmunología , Neoplasias de la Mama/metabolismo , Resistencia a Antineoplásicos , Interleucina-17/biosíntesis , Linfocitos Infiltrantes de Tumor/inmunología , Linfocitos Infiltrantes de Tumor/metabolismo , Sistema de Señalización de MAP Quinasas , Antineoplásicos/farmacología , Biopsia , Neoplasias de la Mama/tratamiento farmacológico , Neoplasias de la Mama/patología , Línea Celular Tumoral , Movimiento Celular/efectos de los fármacos , Proliferación Celular/efectos de los fármacos , Docetaxel , Femenino , Humanos , Interleucina-17/genética , Sistema de Señalización de MAP Quinasas/efectos de los fármacos , Proteína Quinasa 1 Activada por Mitógenos , Proteína Quinasa 3 Activada por Mitógenos , Receptores de Estrógenos/metabolismo , Taxoides/farmacologíaAsunto(s)
Transición Epitelial-Mesenquimal , Células Madre Mesenquimatosas/metabolismo , Proteína-Lisina 6-Oxidasa/metabolismo , Neoplasias de la Mama/metabolismo , Neoplasias de la Mama/patología , Humanos , Ácido Hialurónico/metabolismo , Células Madre Mesenquimatosas/patología , Modelos Biológicos , Proteína 1 Relacionada con Twist/metabolismoRESUMEN
Metastasis is the main cause of death by cancer. Hence, establishing predictive markers constitutes a major clinical objective. The capacity for a tumor cell to migrate and survive from a primary tumor is often described as the ultimate step of Darwinian selection. These metastatic cells are believed to emerge from a subpopulation of cells present in a primary tumor. In line with this hypothesis, various gene "signatures" associated with poor prognosis and/or with tumors displaying high metastatic potential have been promoted. However, over the last few years, a growing body of evidence supports the idea that metastatic cells disseminate early from the primordial tumor and evolve independently of it. Herein, we propose to review to the data favoring this alternative model and discuss the interplay between metastatic mechanisms and failsafe mechanism pathways.
Asunto(s)
Metástasis de la Neoplasia/patología , Lesiones Precancerosas/patología , Animales , Epitelio/patología , Humanos , Mesodermo/patología , Metástasis de la Neoplasia/diagnóstico , PronósticoRESUMEN
Recently, two novel concepts have emerged in cancer biology: the role of so-called "cancer stem cells" in tumor initiation, and the involvement of an epithelial-mesenchymal transition (EMT) in the metastatic dissemination of epithelial cancer cells. Using a mammary tumor progression model, we show that cells possessing both stem and tumorigenic characteristics of "cancer stem cells" can be derived from human mammary epithelial cells following the activation of the Ras-MAPK pathway. The acquisition of these stem and tumorigenic characters is driven by EMT induction.
Asunto(s)
Neoplasias de la Mama/patología , Células Epiteliales/patología , Mesodermo/patología , Células Madre/patología , Mama/citología , Neoplasias de la Mama/virología , Antígeno CD24/análisis , Antígeno CD24/genética , División Celular , Ensayo de Unidades Formadoras de Colonias , Células Epiteliales/citología , Células Epiteliales/virología , Femenino , Citometría de Flujo , Humanos , Receptores de Hialuranos/análisis , Metástasis de la Neoplasia , Retroviridae , Células Madre/citología , Células Madre/virología , Células Tumorales CultivadasRESUMEN
Twist1 and Twist2 are major regulators of embryogenesis. Twist1 has been shown to favor the metastatic dissemination of cancer cells through its ability to induce an epithelial-mesenchymal transition (EMT). Here, we show that a large fraction of human cancers overexpress Twist1 and/or Twist2. Both proteins override oncogene-induced premature senescence by abrogating key regulators of the p53- and Rb-dependent pathways. Twist1 and Twist2 cooperate with Ras to transform mouse embryonic fibroblasts. Interestingly, in epithelial cells, the oncogenic cooperation between Twist proteins and activated mitogenic oncoproteins, such as Ras or ErbB2, leads to complete EMT. These findings suggest an unanticipated direct link between early escape from failsafe programs and the acquisition of invasive features by cancer cells.