RESUMO
BACKGROUND & AIMS: A disintegrin and metalloproteinase domain-containing protein 10 (ADAM10) is a cell surface sheddase that regulates physiologic processes, including Notch signaling. ADAM10 is expressed in all intestinal epithelial cell types, but the requirement for ADAM10 signaling in crypt homeostasis is not well defined. METHODS: We analyzed intestinal tissues from mice with constitutive (Vil-Cre;Adam10(f/f) mice) and conditional (Vil-CreER;Adam10(f/f) and Leucine-rich repeat-containing GPCR5 [Lgr5]-CreER;Adam10(f/f) mice) deletion of ADAM10. We performed cell lineage-tracing experiments in mice that expressed a gain-of-function allele of Notch in the intestine (Rosa26(NICD)), or mice with intestine-specific disruption of Notch (Rosa26(DN-MAML)), to examine the effects of ADAM10 deletion on cell fate specification and intestinal stem cell maintenance. RESULTS: Loss of ADAM10 from developing and adult intestine caused lethality associated with altered intestinal morphology, reduced progenitor cell proliferation, and increased secretory cell differentiation. ADAM10 deletion led to the replacement of intestinal cell progenitors with 2 distinct, post-mitotic, secretory cell lineages: intermediate-like (Paneth/goblet) and enteroendocrine cells. Based on analysis of Rosa26(NICD) and Rosa26(DN-MAML) mice, we determined that ADAM10 controls these cell fate decisions by regulating Notch signaling. Cell lineage-tracing experiments showed that ADAM10 is required for survival of Lgr5(+) crypt-based columnar cells. Our findings indicate that Notch-activated stem cells have a competitive advantage for occupation of the stem cell niche. CONCLUSIONS: ADAM10 acts in a cell autonomous manner within the intestinal crypt compartment to regulate Notch signaling. This process is required for progenitor cell lineage specification and crypt-based columnar cell maintenance.
Assuntos
Proteínas ADAM/metabolismo , Secretases da Proteína Precursora do Amiloide/metabolismo , Intestinos/enzimologia , Proteínas de Membrana/metabolismo , Receptores Notch/metabolismo , Nicho de Células-Tronco , Células-Tronco/enzimologia , Proteínas ADAM/deficiência , Proteínas ADAM/genética , Proteína ADAM10 , Secretases da Proteína Precursora do Amiloide/deficiência , Secretases da Proteína Precursora do Amiloide/genética , Animais , Diferenciação Celular , Linhagem Celular , Linhagem da Célula , Proliferação de Células , Sobrevivência Celular , Células Enteroendócrinas/enzimologia , Células Caliciformes/enzimologia , Intestinos/citologia , Proteínas de Membrana/deficiência , Proteínas de Membrana/genética , Camundongos , Camundongos Knockout , Organoides , Celulas de Paneth/enzimologia , Fenótipo , Transdução de Sinais , Fatores de TempoRESUMO
We screened 124 genes that are amplified in human hepatocellular carcinoma (HCC) using a mouse hepatoblast model and identified 18 tumor-promoting genes, including CCND1 and its neighbor on 11q13.3, FGF19. Although it is widely assumed that CCND1 is the main driving oncogene of this common amplicon (15% frequency in HCC), both forward-transformation assays and RNAi-mediated inhibition in human HCC cells established that FGF19 is an equally important driver gene in HCC. Furthermore, clonal growth and tumorigenicity of HCC cells harboring the 11q13.3 amplicon were selectively inhibited by RNAi-mediated knockdown of CCND1 or FGF19, as well as by an anti-FGF19 antibody. These results show that 11q13.3 amplification could be an effective biomarker for patients most likely to respond to anti-FGF19 therapy.
Assuntos
Carcinoma Hepatocelular/genética , Fatores de Crescimento de Fibroblastos/genética , Neoplasias Hepáticas/genética , Proteínas Oncogênicas/genética , Animais , Anticorpos Monoclonais/imunologia , Anticorpos Monoclonais/farmacologia , Carcinoma Hepatocelular/tratamento farmacológico , Carcinoma Hepatocelular/patologia , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Cromossomos Humanos Par 11/genética , Ciclina D1/genética , Ciclina D1/metabolismo , Feminino , Fatores de Crescimento de Fibroblastos/imunologia , Fatores de Crescimento de Fibroblastos/metabolismo , Amplificação de Genes , Regulação Neoplásica da Expressão Gênica , Predisposição Genética para Doença , Genômica/métodos , Humanos , Immunoblotting , Neoplasias Hepáticas/tratamento farmacológico , Neoplasias Hepáticas/patologia , Camundongos , Camundongos Nus , Proteínas Oncogênicas/metabolismo , Interferência de RNA , Carga Tumoral/efeitos dos fármacos , Ensaios Antitumorais Modelo de XenoenxertoAssuntos
Antineoplásicos/uso terapêutico , Neoplasias/tratamento farmacológico , Medicina de Precisão , Animais , Modelos Animais de Doenças , Descoberta de Drogas , Redes Reguladoras de Genes/genética , Humanos , Camundongos , National Cancer Institute (U.S.) , Proteínas de Neoplasias/metabolismo , Neoplasias/genética , RNA Interferente Pequeno/metabolismo , Estados UnidosRESUMO
Notch signaling is involved both in development as well as in multiple cancers, including pancreatic cancer. Its activity has been implicated early in pancreatic disease, shown to be essential for a pre-cancerous transdifferentiation event known as acinar-to-ductal metaplasia (ADM). Recently, we have shown that matrix metalloproteinase-7 (MMP-7) is essential for ADM by activating the Notch pathway, challenging the notion that ADAM metalloproteinases are the sole enzymes responsible for initiating Notch activity. In ADM, ADAMs do not compensate for the absence of MMP-7 activity. We propose that during development and stem cell maintenance, Notch activation is highly regulated by the binding of Notch ligand to receptor and employs the ubiquitously-expressed ADAMs, whereas in a disease state, high levels of induced MMP-7 activity can lead to aberrant ligand-independent Notch activation. Therefore, if ADM or PDA is to be blocked by inhibiting Notch, treatment with ADAM-specific inhibitors alone will be inadequate. Other approaches for Notch inhibition, including by gamma-secretase and broad-spectrum MMP inhibitors, will be discussed.
Assuntos
Proteínas ADAM/metabolismo , Linhagem da Célula , Receptores Notch/metabolismo , Secretases da Proteína Precursora do Amiloide/metabolismo , Animais , Células COS , Carcinoma Ductal Pancreático/enzimologia , Carcinoma Ductal Pancreático/patologia , Chlorocebus aethiops , Humanos , Metaloproteinase 3 da Matriz/metabolismo , Metaloproteinase 7 da Matriz/metabolismo , Camundongos , Modelos Biológicos , Neoplasias Pancreáticas/enzimologia , Neoplasias Pancreáticas/patologia , Estrutura Terciária de Proteína , Receptores Notch/químicaRESUMO
Acinar-to-ductal metaplasia in the pancreas is associated with an increased risk for tumorigenesis. Molecular dissection of this process in vitro has shown that primary acinar cells, in response to EGF receptor ligands, can transdifferentiate into duct-like epithelia, passing through a nestin-positive intermediate, in a Notch pathway-dependent manner. Here, we show that in vitro acinar transdifferentiation depends on matrix metalloproteinase 7 (MMP-7), a proteinase expressed in most metaplastic epithelia in vivo. MMP-7 was found to be required for Notch activation, which leads to dedifferentiation of acinar cells to the nestin-positive transitional cell. Besides being necessary for acinar transdifferentiation, it was found that MMP-7 activity was sufficient to induce the process, indicating that molecular signals capable of initiating MMP-7 expression also have the potential to induce formation of metaplastic epithelia in the pancreas.
