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1.
Exp Hematol ; : 104177, 2024 Feb 08.
Artigo em Inglês | MEDLINE | ID: mdl-38336135

RESUMO

Emerging evidence implicates the epithelial-mesenchymal transition transcription factor Zeb1 as a critical regulator of hematopoietic stem cell (HSC) differentiation. Whether Zeb1 regulates long-term maintenance of HSC function remains an open question. Using an inducible Mx-1-Cre mouse model that deletes conditional Zeb1 alleles in the adult hematopoietic system, we found that mice engineered to be deficient in Zeb1 for 32 weeks displayed expanded immunophenotypically defined adult HSCs and multipotent progenitors associated with increased abundance of lineage-biased/balanced HSC subsets and augmented cell survival characteristics. During hematopoietic differentiation, persistent Zeb1 loss increased B cells in the bone marrow and spleen and decreased monocyte generation in the peripheral blood. In competitive transplantation experiments, we found that HSCs from adult mice with long-term Zeb1 deletion displayed a cell autonomous defect in multilineage differentiation capacity. Long-term Zeb1 loss perturbed extramedullary hematopoiesis characterized by increased splenic weight and a paradoxical reduction in splenic cellularity that was accompanied by HSC exhaustion, lineage-specific defects, and an accumulation of aberrant, preleukemic like c-kit+CD16/32+ progenitors. Loss of Zeb1 for up to 42 weeks can lead to progressive splenomegaly and an accumulation of Gr-1+Mac-1+ cells, further supporting the notion that long-term expression of Zeb1 suppresses preleukemic activity. Thus, sustained Zeb1 deletion disrupts HSC functionality in vivo and impairs regulation of extramedullary hematopoiesis with potential implications for tumor suppressor functions of Zeb1 in myeloid neoplasms.

2.
Cells Tissues Organs ; 2024 Jan 09.
Artigo em Inglês | MEDLINE | ID: mdl-38194935

RESUMO

TEMTIA X, the tenth symposium organized by the EMT international Association (TEMTIA) took place in Paris on November 7th-10th, 2022. Similarly to the previous meetings, it reviewed most recent aspects of the epithelial-mesenchymal transition, a cellular process involved during distinct stages of development, but also during wound healing and fibrosis to some level. EMT steps are likewise typically described with various extents during tumor cell progression and metastasis. The meeting emphasized the intermediate stages involved in the process and their potential physiological or pathological importance, taking advantage of the expansion of molecular methods at single cell level. It also introduced new descriptions of EMT occurrences during early embryogenesis. In addition, sessions explored how EMT reflects cell metabolism and how the process can mingle with immune response, particularly during tumor progression, providing new targets, that were discussed, among others, for cancer therapy. Finally, it introduced a new perception of EMT biological meaning based on an evolutionary perspective. The meeting integrated the TEMTIA general assembly , allowing general discussion about the future of the association, starting with the site of the next meeting, now decided to take place in Seattle (US), late 2024.

3.
Semin Cancer Biol ; 97: 86-103, 2023 12.
Artigo em Inglês | MEDLINE | ID: mdl-38029866

RESUMO

TGFß signaling and the DNA damage response (DDR) are two cellular toolboxes with a strong impact on cancer biology. While TGFß as a pleiotropic cytokine affects essentially all hallmarks of cancer, the multifunctional DDR mostly orchestrates cell cycle progression, DNA repair, chromatin remodeling and cell death. One oncogenic effect of TGFß is the partial activation of epithelial-to-mesenchymal transition (EMT), conferring invasiveness, cellular plasticity and resistance to various noxae. Several reports show that both individual networks as well as their interface affect chemo-/radiotherapies. However, the underlying mechanisms remain poorly resolved. EMT often correlates with TGFß-induced slowing of proliferation, yet numerous studies demonstrate that particularly the co-activated EMT transcription factors counteract anti-proliferative signaling in a partially non-redundant manner. Collectively, evidence piled up over decades underscore a multifaceted, reciprocal inter-connection of TGFß signaling / EMT with the DDR / cell cycle progression, which we will discuss here. Altogether, we conclude that full cell cycle arrest is barely compatible with the propagation of oncogenic EMT traits and further propose that 'EMT-linked DDR plasticity' is a crucial, yet intricate facet of malignancy, decisively affecting metastasis formation and therapy resistance.


Assuntos
Neoplasias , Fator de Crescimento Transformador beta , Humanos , Fator de Crescimento Transformador beta/metabolismo , Transdução de Sinais , Fatores de Transcrição , Neoplasias/genética , Ciclo Celular/genética , Transição Epitelial-Mesenquimal/genética
4.
Int J Mol Sci ; 24(17)2023 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-37686224

RESUMO

An induction in the expression of the cell adhesion receptor L1, a Wnt target gene, is a characteristic feature of Wnt/ß-catenin activation in colon cancer cells at later stages of the disease. We investigated the proteins secreted following L1 expression in colon cancer cells and identified Mucin2 among the most abundant secreted proteins. We found that suppressing Mucin2 expression in L1-expressing colon cancer cells inhibits cell proliferation, motility, tumorigenesis, and liver metastasis. We detected several signaling pathways involved in Mucin2 induction in L1-expressing cells. In human colon cancer tissue, Mucin2 expression was significantly reduced or lost in the adenocarcinoma tissue, while in the mucinous subtype of colon cancer tissue, Mucin2 expression was increased. An increased signature of L1/Mucin2 expression reduced the survival rate of human colon cancer patients. Thus, induction of Mucin2 expression by L1 is required during mucinous colon cancer progression and can serve as a marker for diagnosis and a target for therapy.


Assuntos
Neoplasias do Colo , Neoplasias Hepáticas , Humanos , Carcinogênese , Transformação Celular Neoplásica , Neoplasias do Colo/genética
5.
Cancer Gene Ther ; 30(9): 1234-1248, 2023 09.
Artigo em Inglês | MEDLINE | ID: mdl-37268816

RESUMO

Limb-Bud and Heart (LBH) is a developmental transcription co-factor deregulated in cancer, with reported oncogenic and tumor suppressive effects. However, LBH expression in most cancer types remains unknown, impeding understanding of its mechanistic function Here, we performed systematic bioinformatic and TMA analysis for LBH in >20 different cancer types. LBH was overexpressed in most cancers compared to normal tissues (>1.5-fold; p < 0.05), including colon-rectal, pancreatic, esophageal, liver, stomach, bladder, kidney, prostate, testicular, brain, head & neck cancers, and sarcoma, correlating with poor prognosis. The cancer types showing LBH downregulation were lung, melanoma, ovarian, cervical, and uterine cancer, while both LBH over- and under-expression were observed in hematopoietic malignancies. In cancers with LBH overexpression, the LBH locus was frequently hypomethylated, identifying DNA hypomethylation as a potential mechanism for LBH dysregulation. Pathway analysis identified a universal, prognostically significant correlation between LBH overexpression and the WNT-Integrin signaling pathways. Validation of the clinical association of LBH with WNT activation in gastrointestinal cancer cell lines, and in colorectal patient samples by IHC uncovered that LBH is specifically expressed in tumor cells with nuclear beta-catenin at the invasive front. Collectively, these data reveal a high degree of LBH dysregulation in cancer and establish LBH as pan-cancer biomarker for detecting WNT hyperactivation in clinical specimens.


Assuntos
Neoplasias , Fatores de Transcrição , Masculino , Humanos , beta Catenina , Metilação de DNA , Linhagem Celular , Via de Sinalização Wnt/genética , DNA , Linhagem Celular Tumoral , Regulação Neoplásica da Expressão Gênica , Neoplasias/genética
6.
Cell Rep ; 41(11): 111819, 2022 12 13.
Artigo em Inglês | MEDLINE | ID: mdl-36516781

RESUMO

The DNA damage response (DDR) and epithelial-to-mesenchymal transition (EMT) are two crucial cellular programs in cancer biology. While the DDR orchestrates cell-cycle progression, DNA repair, and cell death, EMT promotes invasiveness, cellular plasticity, and intratumor heterogeneity. Therapeutic targeting of EMT transcription factors, such as ZEB1, remains challenging, but tumor-promoting DDR alterations elicit specific vulnerabilities. Using multi-omics, inhibitors, and high-content microscopy, we discover a chemoresistant ZEB1-high-expressing sub-population (ZEB1hi) with co-rewired cell-cycle progression and proficient DDR across tumor entities. ZEB1 stimulates accelerated S-phase entry via CDK6, inflicting endogenous DNA replication stress. However, DDR buildups involving constitutive MRE11-dependent fork resection allow homeostatic cycling and enrichment of ZEB1hi cells during transforming growth factor ß (TGF-ß)-induced EMT and chemotherapy. Thus, ZEB1 promotes G1/S transition to launch a progressive DDR benefitting stress tolerance, which concurrently manifests a targetable vulnerability in chemoresistant ZEB1hi cells. Our study thus highlights the translationally relevant intercept of the DDR and EMT.


Assuntos
Fatores de Transcrição , Homeobox 1 de Ligação a E-box em Dedo de Zinco , Fatores de Transcrição/metabolismo , Homeobox 1 de Ligação a E-box em Dedo de Zinco/genética , Homeobox 1 de Ligação a E-box em Dedo de Zinco/metabolismo , Linhagem Celular Tumoral , Transição Epitelial-Mesenquimal/genética , Replicação do DNA
7.
Cancers (Basel) ; 14(18)2022 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-36139637

RESUMO

The immunoglobulin family cell adhesion receptor L1 is induced in CRC cells at the invasive front of the tumor tissue, and confers enhanced proliferation, motility, tumorigenesis, and liver metastasis. To identify putative tumor suppressors whose expression is downregulated in L1-expressing CRC cells, we blocked the L1-ezrin-NF-κB signaling pathway and searched for genes induced under these conditions. We found that TFF1, a protein involved in protecting the mucus epithelial layer of the colon, is downregulated in L1-expressing cells and displays characteristics of a tumor suppressor. Overexpression of TFF1 in L1-transfected human CRC cells blocks the pro-tumorigenic and metastatic properties conferred by L1 by suppressing NF-κB signaling. Immunohistochemical analyses revealed that human CRC tissue samples often lose the expression of TFF1, while the normal mucosa displays TFF1 in goblet cells. Identifying TFF1 as a tumor suppressor in CRC cells could provide a novel marker for L1-mediated CRC development and a potential target for therapy.

8.
J Cell Sci ; 135(20)2022 10 15.
Artigo em Inglês | MEDLINE | ID: mdl-36148682

RESUMO

The ligand-activated transcription factor aryl hydrocarbon receptor (AHR) regulates cellular detoxification, proliferation and immune evasion in a range of cell types and tissues, including cancer cells. In this study, we used RNA-sequencing to identify the signature of the AHR target genes regulated by the pollutant 2,3,7,8-tetrachlorodibenzodioxin (TCDD) and the endogenous ligand kynurenine (Kyn), a tryptophan-derived metabolite. This approach identified a signature of six genes (CYP1A1, ALDH1A3, ABCG2, ADGRF1 and SCIN) as commonly activated by endogenous or exogenous ligands of AHR in multiple colon cancer cell lines. Among these, the actin-severing protein scinderin (SCIN) was necessary for cell proliferation; SCIN downregulation limited cell proliferation and its expression increased it. SCIN expression was elevated in a subset of colon cancer patient samples, which also contained elevated ß-catenin levels. Remarkably, SCIN expression promoted nuclear translocation of ß-catenin and activates the WNT pathway. Our study identifies a new mechanism for adhesion-mediated signaling in which SCIN, likely via its ability to alter the actin cytoskeleton, facilitates the nuclear translocation of ß-catenin. This article has an associated First Person interview with the first authors of the paper.


Assuntos
Neoplasias do Colo , Poluentes Ambientais , Dibenzodioxinas Policloradas , Humanos , Receptores de Hidrocarboneto Arílico/genética , Receptores de Hidrocarboneto Arílico/metabolismo , beta Catenina/genética , beta Catenina/metabolismo , Via de Sinalização Wnt/genética , Citocromo P-450 CYP1A1/genética , Citocromo P-450 CYP1A1/metabolismo , Ligantes , Cinurenina , Triptofano , Actinas/metabolismo , Neoplasias do Colo/genética , RNA
9.
Cell Rep ; 38(2): 110240, 2022 01 11.
Artigo em Inglês | MEDLINE | ID: mdl-35021086

RESUMO

Maintenance of undifferentiated, long-lived, and often quiescent stem cells in the basal compartment is important for homeostasis and regeneration of multiple epithelial tissues, but the molecular mechanisms that coordinately control basal cell fate and stem cell quiescence are elusive. Here, we report an epithelium-intrinsic requirement for Zeb1, a core transcriptional inducer of epithelial-to-mesenchymal transition, for mammary epithelial ductal side branching and for basal cell regenerative capacity. Our findings uncover an evolutionarily conserved role of Zeb1 in promoting basal cell fate over luminal differentiation. We show that Zeb1 loss results in increased basal cell proliferation at the expense of quiescence and self-renewal. Moreover, Zeb1 cooperates with YAP to activate Axin2 expression, and inhibition of Wnt signaling partially restores stem cell function to Zeb1-deficient basal cells. Thus, Zeb1 is a transcriptional regulator that maintains both basal cell fate and stem cell quiescence, and it functions in part through suppressing Wnt signaling.


Assuntos
Linhagem da Célula/genética , Células-Tronco/metabolismo , Homeobox 1 de Ligação a E-box em Dedo de Zinco/metabolismo , Células 3T3 , Animais , Proteína Axina/metabolismo , Diferenciação Celular , Proliferação de Células , Células Epiteliais/metabolismo , Transição Epitelial-Mesenquimal/genética , Células HEK293 , Humanos , Camundongos , Camundongos Endogâmicos C57BL , Fatores de Transcrição , Via de Sinalização Wnt/fisiologia , Homeobox 1 de Ligação a E-box em Dedo de Zinco/genética
10.
Front Cell Dev Biol ; 9: 753456, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34888306

RESUMO

Pancreatic cancer is a very aggressive disease with 5-year survival rates of less than 10%. The constantly increasing incidence and stagnant patient outcomes despite changes in treatment regimens emphasize the requirement of a better understanding of the disease mechanisms. Challenges in treating pancreatic cancer include diagnosis at already progressed disease states due to the lack of early detection methods, rapid acquisition of therapy resistance, and high metastatic competence. Pancreatic ductal adenocarcinoma, the most prevalent type of pancreatic cancer, frequently shows dominant-active mutations in KRAS and TP53 as well as inactivation of genes involved in differentiation and cell-cycle regulation (e.g. SMAD4 and CDKN2A). Besides somatic mutations, deregulated transcription factor activities strongly contribute to disease progression. Specifically, transcriptional regulatory networks essential for proper lineage specification and differentiation during pancreas development are reactivated or become deregulated in the context of cancer and exacerbate progression towards an aggressive phenotype. This review summarizes the recent literature on transcription factor networks and epigenetic gene regulation that play a crucial role during tumorigenesis.

11.
PLoS Biol ; 19(9): e3001394, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34550965

RESUMO

The ZEB2 transcription factor has been demonstrated to play important roles in hematopoiesis and leukemic transformation. ZEB1 is a close family member of ZEB2 but has remained more enigmatic concerning its roles in hematopoiesis. Here, we show using conditional loss-of-function approaches and bone marrow (BM) reconstitution experiments that ZEB1 plays a cell-autonomous role in hematopoietic lineage differentiation, particularly as a positive regulator of monocyte development in addition to its previously reported important role in T-cell differentiation. Analysis of existing single-cell (sc) RNA sequencing (RNA-seq) data of early hematopoiesis has revealed distinctive expression differences between Zeb1 and Zeb2 in hematopoietic stem and progenitor cell (HSPC) differentiation, with Zeb2 being more highly and broadly expressed than Zeb1 except at a key transition point (short-term HSC [ST-HSC]➔MPP1), whereby Zeb1 appears to be the dominantly expressed family member. Inducible genetic inactivation of both Zeb1 and Zeb2 using a tamoxifen-inducible Cre-mediated approach leads to acute BM failure at this transition point with increased long-term and short-term hematopoietic stem cell numbers and an accompanying decrease in all hematopoietic lineage differentiation. Bioinformatics analysis of RNA-seq data has revealed that ZEB2 acts predominantly as a transcriptional repressor involved in restraining mature hematopoietic lineage gene expression programs from being expressed too early in HSPCs. ZEB1 appears to fine-tune this repressive role during hematopoiesis to ensure hematopoietic lineage fidelity. Analysis of Rosa26 locus-based transgenic models has revealed that Zeb1 as well as Zeb2 cDNA-based overexpression within the hematopoietic system can drive extramedullary hematopoiesis/splenomegaly and enhance monocyte development. Finally, inactivation of Zeb2 alone or Zeb1/2 together was found to enhance survival in secondary MLL-AF9 acute myeloid leukemia (AML) models attesting to the oncogenic role of ZEB1/2 in AML.


Assuntos
Linhagem da Célula , Células-Tronco Hematopoéticas/metabolismo , Leucemia Mieloide Aguda/metabolismo , Homeobox 2 de Ligação a E-box com Dedos de Zinco/metabolismo , Homeobox 1 de Ligação a E-box em Dedo de Zinco/metabolismo , Animais , Células da Medula Óssea/patologia , Diferenciação Celular , Regulação Neoplásica da Expressão Gênica , Hematopoese , Células-Tronco Hematopoéticas/patologia , Leucemia Mieloide Aguda/patologia , Camundongos , Camundongos Transgênicos , RNA-Seq , Homeobox 2 de Ligação a E-box com Dedos de Zinco/genética , Homeobox 1 de Ligação a E-box em Dedo de Zinco/genética
12.
EMBO J ; 40(18): e108647, 2021 09 15.
Artigo em Inglês | MEDLINE | ID: mdl-34459003

RESUMO

The process of epithelial-mesenchymal transition (EMT) is fundamental for embryonic morphogenesis. Cells undergoing it lose epithelial characteristics and integrity, acquire mesenchymal features, and become motile. In cancer, this program is hijacked to confer essential changes in morphology and motility that fuel invasion. In addition, EMT is increasingly understood to orchestrate a large variety of complementary cancer features, such as tumor cell stemness, tumorigenicity, resistance to therapy and adaptation to changes in the microenvironment. In this review, we summarize recent findings related to these various classical and non-classical functions, and introduce EMT as a true tumorigenic multi-tool, involved in many aspects of cancer. We suggest that therapeutic targeting of the EMT process will-if acknowledging these complexities-be a possibility to concurrently interfere with tumor progression on many levels.


Assuntos
Transição Epitelial-Mesenquimal , Neoplasias/etiologia , Neoplasias/patologia , Microambiente Tumoral , Animais , Biomarcadores , Transformação Celular Neoplásica , Progressão da Doença , Transição Epitelial-Mesenquimal/genética , Regulação Neoplásica da Expressão Gênica , Humanos , Neoplasias/metabolismo , Transdução de Sinais , Microambiente Tumoral/genética
13.
Cell Death Discov ; 7(1): 138, 2021 Jun 11.
Artigo em Inglês | MEDLINE | ID: mdl-34112759

RESUMO

The pancreas is comprised of exocrine and endocrine compartments releasing digestive enzymes into the duodenum and regulating blood glucose levels by insulin and glucagon release. Tissue homeostasis is depending on transcription factor networks, involving Ptf1α, Ngn3, Nkx6.1, and Sox9, which are already activated during organogenesis. However, proper organ function is challenged by diets of high sugar and fat content, increasing the risk of type 2 diabetes and other disorders. A detailed understanding of processes that are important for homeostasis and are impaired during type 2 diabetes is lacking. Here, we show that Zeb1-a transcription factor known for its pivotal role in epithelial-mesenchymal transition, cell plasticity, and metastasis in cancer-is expressed at low levels in epithelial cells of the pancreas and is crucial for organogenesis and pancreas function. Loss of Zeb1 in these cells result in an increase of islet mass, impaired glucose tolerance, and sensitizes to develop liver and pancreas steatosis during diabetes and obesity. Interestingly, moderate overexpression of Zeb1 results in severe pancreas agenesis and lethality after birth, due to islet insufficiency and lack of acinar structures. We show that Zeb1 induction interferes with proper differentiation, cell survival, and proliferation during pancreas formation, due to deregulated expression of endocrine-specific transcription factors. In summary, our analysis suggests a novel role of Zeb1 for homeostasis in epithelial cells that is indispensable for pancreas morphogenesis and proper organ function involving a tight regulation of Zeb1 expression.

14.
Int J Mol Sci ; 22(7)2021 Mar 29.
Artigo em Inglês | MEDLINE | ID: mdl-33805564

RESUMO

The overactivation of Wnt/ß-catenin signaling is a hallmark of colorectal cancer (CRC) development. We identified the cell adhesion molecule L1CAM (L1) as a target of ß-catenin-TCF transactivation in CRC cells. The overexpression of L1 in CRC cells confers enhanced proliferation, motility, tumorigenesis and liver metastasis, and L1 is exclusively localized in the invasive areas of human CRC tissue. A number of genes are induced after L1 transfection into CRC cells by a mechanism involving the cytoskeletal protein ezrin and the NF-κB pathway. When studying the changes in gene expression in CRC cells overexpressing L1 in which ezrin levels were suppressed by shRNA to ezrin, we discovered the collagen-modifying enzyme lysyl hydroxylase 2 (PLOD2) among these genes. We found that increased PLOD2 expression was required for the cellular processes conferred by L1, including enhanced proliferation, motility, tumorigenesis and liver metastasis, since the suppression of endogenous PLOD2 expression, or its enzymatic activity, blocked the enhanced tumorigenic properties conferred by L1. The mechanism involved in increased PLOD2 expression by L1 involves ezrin signaling and PLOD2 that affect the SMAD2/3 pathway. We found that PLOD2 is localized in the colonic crypts in the stem cell compartment of the normal mucosa and is found at increased levels in invasive areas of the tumor and, in some cases, throughout the tumor tissue. The therapeutic strategies to target PLOD2 expression might provide a useful approach for CRC treatment.


Assuntos
Neoplasias do Colo/patologia , Pró-Colágeno-Lisina 2-Oxoglutarato 5-Dioxigenase/metabolismo , Animais , Linhagem Celular Tumoral , Movimento Celular , Colágeno/metabolismo , Neoplasias do Colo/genética , Neoplasias do Colo/metabolismo , Proteínas do Citoesqueleto/metabolismo , Regulação Neoplásica da Expressão Gênica , Mucosa Intestinal/metabolismo , Mucosa Intestinal/patologia , Neoplasias Hepáticas/patologia , Neoplasias Hepáticas/secundário , Masculino , Camundongos Nus , Molécula L1 de Adesão de Célula Nervosa/metabolismo , Pró-Colágeno-Lisina 2-Oxoglutarato 5-Dioxigenase/genética , Proteína Smad2/metabolismo , Proteína Smad3/metabolismo , Ensaios Antitumorais Modelo de Xenoenxerto
15.
Life Sci Alliance ; 4(6)2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-33758075

RESUMO

Citrate is important for lipid synthesis and epigenetic regulation in addition to ATP production. We have previously reported that cancer cells import extracellular citrate via the pmCiC transporter to support their metabolism. Here, we show for the first time that citrate is supplied to cancer by cancer-associated stroma (CAS) and also that citrate synthesis and release is one of the latter's major metabolic tasks. Citrate release from CAS is controlled by cancer cells through cross-cellular communication. The availability of citrate from CAS regulated the cytokine profile, metabolism and features of cellular invasion. Moreover, citrate released by CAS is involved in inducing cancer progression especially enhancing invasiveness and organ colonisation. In line with the in vitro observations, we show that depriving cancer cells of citrate using gluconate, a specific inhibitor of pmCiC, significantly reduced the growth and metastatic spread of human pancreatic cancer cells in vivo and muted stromal activation and angiogenesis. We conclude that citrate is supplied to tumour cells by CAS and citrate uptake plays a significant role in cancer metastatic progression.


Assuntos
Fibroblastos Associados a Câncer/metabolismo , Ácido Cítrico/metabolismo , Neoplasias Pancreáticas/metabolismo , Fibroblastos Associados a Câncer/fisiologia , Linhagem Celular Tumoral , Epigênese Genética , Humanos , Metástase Neoplásica/genética , Metástase Neoplásica/patologia , Neoplasias Pancreáticas/patologia , Células Estromais/metabolismo , Microambiente Tumoral/fisiologia , Neoplasias Pancreáticas
16.
J Pathol ; 254(2): 199-211, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-33675037

RESUMO

Osteosarcoma is an often-fatal mesenchyme-derived malignancy in children and young adults. Overexpression of EMT-transcription factors (EMT-TFs) has been associated with poor clinical outcome. Here, we demonstrated that the EMT-TF ZEB1 is able to block osteoblastic differentiation in normal bone development as well as in osteosarcoma cells. Consequently, overexpression of ZEB1 in osteosarcoma characterizes poorly differentiated, highly metastatic subgroups and its depletion induces differentiation of osteosarcoma cells. Overexpression of ZEB1 in osteosarcoma is frequently associated with silencing of the imprinted DLK-DIO3 locus, which encodes for microRNAs targeting ZEB1. Epigenetic reactivation of this locus in osteosarcoma cells reduces ZEB1 expression, induces differentiation, and sensitizes to standard treatment, thus indicating therapeutic options for ZEB1-driven osteosarcomas. © 2021 The Authors. The Journal of Pathology published by John Wiley & Sons, Ltd. on behalf of The Pathological Society of Great Britain and Ireland.


Assuntos
Neoplasias Ósseas/patologia , Regulação Neoplásica da Expressão Gênica , MicroRNAs/genética , Osteossarcoma/patologia , Homeobox 1 de Ligação a E-box em Dedo de Zinco/metabolismo , Animais , Desenvolvimento Ósseo , Neoplasias Ósseas/tratamento farmacológico , Diferenciação Celular , Linhagem Celular , Proliferação de Células , Epigenômica , Expressão Gênica , Humanos , Células-Tronco Mesenquimais/patologia , Camundongos , Osteoblastos/patologia , Osteossarcoma/tratamento farmacológico , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Homeobox 1 de Ligação a E-box em Dedo de Zinco/genética
17.
Oncogene ; 40(12): 2309-2322, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-33654197

RESUMO

Since their discovery, microRNAs (miRNAs) have been widely studied in almost every aspect of biology and medicine, leading to the identification of important gene regulation circuits and cellular mechanisms. However, investigations are generally focused on the analysis of their downstream targets and biological functions in overexpression and knockdown approaches, while miRNAs endogenous levels and activity remain poorly understood. Here, we used the cellular plasticity-regulating process of epithelial-to-mesenchymal transition (EMT) as a model to show the efficacy of a fluorescent sensor to separate cells with distinct EMT signatures, based on miR-200b/c activity. The system was further combined with a CRISPR-Cas9 screening platform to unbiasedly identify miR-200b/c upstream regulating genes. The sensor allows to infer miRNAs fundamental biological properties, as profiling of sorted cells indicated miR-200b/c as a molecular switch between EMT differentiation and proliferation, and suggested a role for metabolic enzymes in miR-200/EMT regulation. Analysis of miRNAs endogenous levels and activity for in vitro and in vivo applications could lead to a better understanding of their biological role in physiology and disease.


Assuntos
Plasticidade Celular/genética , Neoplasias Colorretais/genética , Transição Epitelial-Mesenquimal/genética , MicroRNAs/genética , Diferenciação Celular/genética , Proliferação de Células/genética , Neoplasias Colorretais/patologia , Células HCT116 , Humanos
18.
Int J Mol Sci ; 23(1)2021 Dec 31.
Artigo em Inglês | MEDLINE | ID: mdl-35008869

RESUMO

Aberrant activation of Wnt/ß-catenin signaling and downstream ß-catenin-TCF target genes is a hallmark of colorectal cancer (CRC) development. We identified the immunoglobulin-like cell adhesion receptor L1CAM (L1) as a target of ß-catenin-TCF transactivation in CRC cells. Overexpression of L1 in CRC cells confers enhanced proliferation, motility, tumorigenesis, and liver metastasis, and L1 is exclusively localized at invasive areas of human CRC tissue. Several genes are induced after L1 transfection into CRC cells by a mechanism involving the L1-ezrin-NF-κB pathway. We conducted a secretomic analysis of the proteins in the culture medium of L1-overexpressing CRC cells. We detected a highly increased level of biglycan, a small leucine-rich ECM component, and a signaling molecule. We found that induction of biglycan is required for the cellular processes conferred by L1, including enhanced proliferation, motility, tumorigenesis, and liver metastasis. The suppression of endogenous biglycan levels or a point mutation in the L1 ectodomain that regulates cell-cell adhesion mediated by L1 blocked the enhanced tumorigenic properties conferred by L1. The mechanism of biglycan induction by L1 involves the L1-NF-κB pathway. Blocking NF-κB signaling in L1 expressing cells suppressed the induction of biglycan and the tumorigenic properties conferred by L1. Biglycan expression was undetectable in the normal colonic mucosa, but expressed at highly increased levels in the tumor tissue, especially in the stroma. The therapeutic strategies to target biglycan expression might provide a useful approach for CRC treatment in L1-overexpressing tumors.


Assuntos
Biglicano/metabolismo , Moléculas de Adesão Celular/metabolismo , Neoplasias Colorretais/metabolismo , NF-kappa B/metabolismo , Animais , Adesão Celular , Linhagem Celular Tumoral , Movimento Celular , Humanos , Masculino , Camundongos , Camundongos Nus
19.
J Clin Invest ; 131(1)2021 01 04.
Artigo em Inglês | MEDLINE | ID: mdl-33108352

RESUMO

Zeb1, a zinc finger E-box binding homeobox epithelial-mesenchymal transition (EMT) transcription factor, confers properties of "stemness," such as self-renewal, in cancer. Yet little is known about the function of Zeb1 in adult stem cells. Here, we used the hematopoietic system as a well-established paradigm of stem cell biology to evaluate Zeb1-mediated regulation of adult stem cells. We employed a conditional genetic approach using the Mx1-Cre system to specifically knock out (KO) Zeb1 in adult hematopoietic stem cells (HSCs) and their downstream progeny. Acute genetic deletion of Zeb1 led to rapid-onset thymic atrophy and apoptosis-driven loss of thymocytes and T cells. A profound cell-autonomous self-renewal defect and multilineage differentiation block were observed in Zeb1-KO HSCs. Loss of Zeb1 in HSCs activated transcriptional programs of deregulated HSC maintenance and multilineage differentiation genes and of cell polarity consisting of cytoskeleton-, lipid metabolism/lipid membrane-, and cell adhesion-related genes. Notably, epithelial cell adhesion molecule (EpCAM) expression was prodigiously upregulated in Zeb1-KO HSCs, which correlated with enhanced cell survival, diminished mitochondrial metabolism, ribosome biogenesis, and differentiation capacity and an activated transcriptomic signature associated with acute myeloid leukemia (AML) signaling. ZEB1 expression was downregulated in AML patients, and Zeb1 KO in the malignant counterparts of HSCs - leukemic stem cells (LSCs) - accelerated MLL-AF9- and Meis1a/Hoxa9-driven AML progression, implicating Zeb1 as a tumor suppressor in AML LSCs. Thus, Zeb1 acts as a transcriptional regulator in hematopoiesis, critically coordinating HSC self-renewal, apoptotic, and multilineage differentiation fates required to suppress leukemic potential in AML.


Assuntos
Células-Tronco Hematopoéticas/metabolismo , Leucemia Mieloide Aguda/metabolismo , Células-Tronco Neoplásicas/metabolismo , Proteínas Supressoras de Tumor/metabolismo , Homeobox 1 de Ligação a E-box em Dedo de Zinco/metabolismo , Animais , Deleção de Genes , Células-Tronco Hematopoéticas/patologia , Leucemia Mieloide Aguda/genética , Leucemia Mieloide Aguda/patologia , Camundongos , Camundongos Knockout , Células-Tronco Neoplásicas/patologia , Proteínas Supressoras de Tumor/genética , Homeobox 1 de Ligação a E-box em Dedo de Zinco/genética
20.
Nat Protoc ; 16(1): 61-85, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-33318692

RESUMO

Despite advances in the detection and therapy of colorectal cancer (CRC) in recent years, CRC has remained a major challenge in clinical practice. Although alternative methods for modeling CRC have been developed, animal models of CRC remain helpful when analyzing molecular aspects of pathogenesis and are often used to perform preclinical in vivo studies of potential therapeutics. This protocol updates our protocol published in 2007, which provided an azoxymethane (AOM)-based setup for investigations into sporadic (Step 5A) and, when combined with dextran sodium sulfate (Step 5B), inflammation-associated tumor growth. This update also extends the applications beyond those of the original protocol by including an option in which AOM is serially applied to mice with p53 deficiency in the intestinal epithelium (Step 5C). In this model, the combination of p53 deficiency and AOM promotes tumor development, including growth of invasive cancers and lymph node metastasis. It also provides details on analysis of colorectal tumor growth and metastasis, including analysis of partial epithelial-to-mesenchymal transition, cell isolation and co-culture studies, high-resolution mini-endoscopy, light-sheet fluorescence microscopy and micro-CT imaging in mice. The target audience for our protocol is researchers who plan in vivo studies to address mechanisms influencing sporadic or inflammation-driven tumor development, including the analysis of local invasiveness and lymph node metastasis. It is suitable for preclinical in vivo testing of novel drugs and other interventional strategies for clinical translation, plus the evaluation of emerging imaging devices/modalities. It can be completed within 24 weeks (using Step 5A/C) or 10 weeks (using Step 5B).


Assuntos
Neoplasias do Colo/patologia , Inflamação/patologia , Metástase Linfática/patologia , Animais , Azoximetano , Neoplasias do Colo/induzido quimicamente , Neoplasias do Colo/complicações , Sulfato de Dextrana , Modelos Animais de Doenças , Progressão da Doença , Feminino , Inflamação/induzido quimicamente , Inflamação/complicações , Masculino , Camundongos , Camundongos Endogâmicos C57BL
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