Stem Cells and Cancer Group

Madrid, Spain

Stem Cells and Cancer Group

Madrid, Spain
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Sainz B.,Stem Cells and Cancer Group | Sainz B.,Autonomous University of Madrid | Martin B.,Autonomous University of Madrid | Tatari M.,Stem Cells and Cancer Group | And 3 more authors.
Cancer Research | Year: 2014

Cancer stem cells (CSC) are thought to play a major role in the development and metastatic progression of pancreatic ductal adenocarcinoma (PDAC), one of the deadliest solid tumors. Likewise, the tumor microenvironment contributes critical support in this setting, including from tumor stromal cells and tumor-associated macrophages (TAM) that contribute structural and paracrine-mediated supports, respectively. Here, we show that TAMs secrete the IFN-stimulated factor ISG15, which enhances CSC phenotypes in PDAC in vitro and in vivo. ISG15 was preferentially and highly expressed by TAM present in primary PDAC tumors resected from patients. ISG15 was secreted by macrophages in response to secretion of IFNb by CSC, thereby reinforcing CSC selfrenewal, invasive capacity, and tumorigenic potential. Overall, our work demonstrates that ISG15 is a previously unrecognized support factor for CSC in the PDAC microenvironment with a key role in pathogenesis and progression. ©2014 AACR.

Miranda-Lorenzo I.,Stem Cells and Cancer Group | Dorado J.,Stem Cells and Cancer Group | Lonardo E.,Stem Cells and Cancer Group | Alcala S.,Stem Cells and Cancer Group | And 13 more authors.
Nature Methods | Year: 2014

Cancer stem cells (CSCs) are thought to drive tumor growth, metastasis and chemoresistance. Although surface markers such as CD133 and CD44 have been successfully used to isolate CSCs, their expression is not exclusively linked to the CSC phenotype and is prone to environmental alteration. We identified cells with an autofluorescent subcellular compartment that exclusively showed CSC features across different human tumor types. Primary tumor-derived autofluorescent cells did not overlap with side-population (SP) cells, were enriched in sphere culture and during chemotherapy, strongly expressed pluripotency-associated genes, were highly metastatic and showed long-term in vivo tumorigenicity, even at the single-cell level. Autofluorescence was due to riboflavin accumulation in membrane-bounded cytoplasmic structures bearing ATP-dependent ABCG2 transporters. In summary, we identified and characterized an intrinsic autofluorescent phenotype in CSCs of diverse epithelial cancers and used this marker to isolate and characterize these cells. © 2014 Nature America, Inc.

Cioffi M.,Stem Cells and Cancer Group | Trabulo S.M.,Stem Cells and Cancer Group | Sanchez-Ripoll Y.,Stem Cells and Cancer Group | Miranda-Lorenzo I.,Stem Cells and Cancer Group | And 10 more authors.
Gut | Year: 2015

Objective Cancer stem cells (CSCs) represent the root of many solid cancers including pancreatic ductal adenocarcinoma, are highly chemoresistant and represent the cellular source for disease relapse. However the mechanisms involved in these processes still need to be fully elucidated. Understanding the mechanisms implicated in chemoresistance and metastasis of pancreatic cancer is critical to improving patient outcomes. Design Micro-RNA (miRNA) expression analyses were performed to identify functionally defining epigenetic signatures in pancreatic CSC-enriched sphere-derived cells and gemcitabine-resistant pancreatic CSCs. Results We found the miR-17-92 cluster to be downregulated in chemoresistant CSCs versus non-CSCs and demonstrate its crucial relevance for CSC biology. In particular, overexpression of miR-17-92 reduced CSC self-renewal capacity, in vivo tumourigenicity and chemoresistance by targeting multiple NODAL/ACTIVIN/TGF-β1 signalling cascade members as well as directly inhibiting the downstream targets p21, p57 and TBX3. Overexpression of miR-17-92 translated into increased CSC proliferation and their eventual exhaustion via downregulation of p21 and p57. Finally, the translational impact of our findings could be confirmed in preclinical models for pancreatic cancer. Conclusions Our findings therefore identify the miR-17-92 cluster as a functionally determining family of miRNAs in CSCs, and highlight the putative potential of developing modulators of this cluster to overcome drug resistance in pancreatic CSCs.

Cioffi M.,Stem Cells and Cancer Group | Trabulo S.,Stem Cells and Cancer Group | Trabulo S.,Barts Cancer Institute | Hidalgo M.,Gastrointestinal Cancer Clinical Research Unit | And 8 more authors.
Clinical Cancer Research | Year: 2015

Purpose: Pancreatic ductal adenocarcinoma (PDAC) is a cancer of the exocrine pancreas with unmet medical need and is strongly promoted by tumor-Associated macrophages (TAM). The presence of TAMs is associated with poor clinical outcome, and their overall role, therefore, appears to be protumorigenic. The don't eat me signal CD47 on cancer cells communicates to the signal regulatory protein-A on macrophages and prevents their phagocytosis. Thus, inhibition of CD47 may offer a new opportunity to turn TAMs against PDAC cells, including cancer stem cells (CSC), as the exclusively tumorigenic population. Experimental Design: We studied in vitro and in vivo the effects ofCD47inhibition on CSCs using a large set of primary pancreatic cancer (stem) cells as well as xenografts of primary human PDAC tissue. Results: CD47 was highly expressed on CSCs, but not on other nonmalignant cells in the pancreas. Targeting CD47 efficiently enhanced phagocytosis of a representative set of primary human pancreatic cancer (stem) cells and, even more intriguingly, also directly induced their apoptosis in the absence of macrophages during long-Term inhibition of CD47. In patient-derived xenograft models, CD47 targeting alone did not result in relevant slowing of tumor growth, but the addition of gemcitabine or Abraxane resulted in sustained tumor regression and prevention of disease relapse long after discontinuation of treatment. Conclusions: These data are consistent with efficient in vivo targeting of CSCs, and strongly suggest that CD47 inhibition could be a novel adjuvant treatment strategy for PDAC independent of underlying and highly variable driver mutations. © 2015 American Association for Cancer Research.

Lonardo E.,Stem Cells and Cancer Group | Cioffi M.,Stem Cells and Cancer Group | Sancho P.,Stem Cells and Cancer Group | Sanchez-Ripoll Y.,Stem Cells and Cancer Group | And 5 more authors.
PLoS ONE | Year: 2013

Pancreatic ductal adenocarcinomas contain a subset of exclusively tumorigenic cancer stem cells (CSCs), which are capable of repopulating the entire heterogeneous cancer cell populations and are highly resistant to standard chemotherapy. Here we demonstrate that metformin selectively ablated pancreatic CSCs as evidenced by diminished expression of pluripotency-associated genes and CSC-associated surface markers. Subsequently, the ability of metformin-treated CSCs to clonally expand in vitro was irreversibly abrogated by inducing apoptosis. In contrast, non-CSCs preferentially responded by cell cycle arrest, but were not eliminated by metformin treatment. Mechanistically, metformin increased reactive oxygen species production in CSC and reduced their mitochondrial transmembrane potential. The subsequent induction of lethal energy crisis in CSCs was independent of AMPK/mTOR. Finally, in primary cancer tissue xenograft models metformin effectively reduced tumor burden and prevented disease progression; if combined with a stroma-targeting smoothened inhibitor for enhanced tissue penetration, while gemcitabine actually appeared dispensable. © 2013 Lonardo et al.

Cioffi M.,Stem Cells and Cancer Group | Dorado J.,Stem Cells and Cancer Group | Baeuerle P.A.,Micromet Inc. | Heeschen C.,Stem Cells and Cancer Group
Clinical Cancer Research | Year: 2012

Purpose: Tumor-initiating cells with stem-like properties, also termed cancer stem cells (CSC), have been shown to sustain tumor growth as well as metastasis and are highly resistant to chemotherapy. Because pancreatic CSCs have been isolated on the basis of EpCAM expression, we investigated whether a targeted immunotherapy to EpCAM using the bispecific T-cell-engaging antibody MT110 is capable of eradicating CSCs. Experimental Design: Westudied in vitro and in vivo the effects of MT110 on CSCs using both established cell lines as well as primary cells of human pancreatic cancer. Results: Although established cell lines were more responsive to MT110-engaged T cells, also primary cells showed a time- and dose-dependent response to treatment with the bispecific antibody. In addition, the population of highly tumorigenic CSCs was efficiently targeted by the EpCAM/CD3-bispecific antibody MT110 in vitro and in vivo using a mouse model of established primary pancreatic cancer. Pancreatic cancer cells derived from metastases were slightly more resistant to MT110 treatment on the basis of in vivo tumorigenicity studies. This appeared to be related to a higher frequency of an EpCAM-negative subpopulation of CSCs. Conclusions: Cytotoxic T cells can be effectively redirected against primary human pancreatic cancer cells by T-cell-engaging BiTE antibody MT110 including a subpopulation of highly tumorigenic CSCs. ©2011 AACR.

Trakala M.,Cell Division and Cancer Group | Fernandez-Miranda G.,Cell Division and Cancer Group | De Castro I.P.,Cell Division and Cancer Group | Heeschen C.,Stem Cells and Cancer Group | Malumbres M.,Cell Division and Cancer Group
Cell Cycle | Year: 2013

Aurora kinase B is a critical component of the chromosomal passenger complex, which is involved in the regulation of microtubule-kinetochore attachments and cytokinesis. By using conditional knockout cells and chemical inhibition, we show here that inactivation of Aurora B results in delayed G 1/S transition and premature mitotic exit. Aurora B deficiency results in delayed DNA replication in cultured fibroblasts as well as liver cells after hepatectomy. This is accompanied by increased transcription of the cell cycle inhibitor p21Cip1. Lack of Aurora B does not prevent mitotic entry but results in a premature exit from prometaphase in the presence of increased p21Cip1-Cdk1 inactive complexes. Aurora B-null cells display reduced degradation of cyclin B1, suggesting the presence of phenomenon known as adaptation to the mitotic checkpoint, previously described in yeast. Elimination of p21Cip1 rescues Cdk1 activity and prevents premature mitotic exit in Aurora B-deficient cells. These results suggest that Aurora B represses p21Cip1, preventing delayed DNA replication, Cdk inhibition and premature mitotic exit. The upregulation of p21Cip1 observed after inhibitio of Aurora B may haves important implications in cell cycle progression, tetraploidy, senescence or cancer therapy. Copyright © 2013 Landes Bioscience.

Lonardo E.,Stem Cells and Cancer Group | Frias-Aldeguer J.,Stem Cells and Cancer Group | Hermann P.C.,Stem Cells and Cancer Group | Heeschen C.,Stem Cells and Cancer Group
Cell Cycle | Year: 2012

Chronic pancreatitis and pancreatic ductal adenocarcinoma (PDAC) are characterized by extensive fibrosis. Importantly, in PDAC, this results in poor vascularization and impaired drug delivery to the cancer cells. Therefore, the combined targeting of pancreatic tumor stroma and chemotherapy should enhance response rates, but the negative outcome of a recent phase III clinical trial for the combination of chemotherapy and hedgehog pathway inhibition suggests that other means also need to be considered. Emerging data indicate that elimination of cancer stem cells as the root of the cancer is of pivotal importance for efficient treatment of pancreatic cancer. Recently, we demonstrated in a highly relevant preclinical mouse model for primary human pancreatic cancers that the combination of cancer stem cell-targeting strategies in combination with a stroma-targeting agent, such as a hedgehog pathway inhibitor and chemotherapy, results in significantly enhanced long-term and progression-free survival. In the present study, we demonstrate mechanistically that Nodal/Activinexpressing pancreatic stellate cells are an important component of the tumor stroma for creating a paracrine niche for pancreatic cancer stem cells. Secretion of the embryonic morphogens Nodal/Activin by pancreatic stellate cells promoted in vitro sphere formation and invasiveness of pancreatic cancer stem cells in an Alk4 receptor-dependent manner. These data imply that the pancreatic cancer stem cell phenotype is promoted by paracrine Nodal/Activin signaling at the tumor-stroma interface. Therefore, targeting the tumor microenvironment is not only able to improve drug delivery but, even more importantly, destroys the cancer stem cell niche and, therefore, should be an integral part of cancer stem cell-based treatment strategies. © 2012 Landes Bioscience.

Cioffi M.,Stem Cells and Cancer Group | Heeschen C.,Stem Cells and Cancer Group
OncoImmunology | Year: 2012

Pancreatic cancer is a highly aggressive and deadly disease harboring a distinct population of cancer stem cells (CSC) that is not affected by conventional therapies. A new therapeutic approach using the EpCAM/CD3-bispecific antibody MT110 is capable of activating and redirecting cytotoxic T cells to eliminate primary human pancreatic cancer stem cells, which resulted in long-term survival of preclinical xenografts models. © 2012 Landes Bioscience.

Dorado J.,Stem Cells and Cancer Group | Lonardo E.,Stem Cells and Cancer Group | Miranda-Lorenzo I.,Stem Cells and Cancer Group | Heeschen C.,Stem Cells and Cancer Group
Journal of Gastroenterology | Year: 2011

Since the identification of self-renewing cells in the hematopoietic system several decades ago, stem cells have changed the way we study biology and medicine. Solid tumors contain a distinct subpopulation of cells that have stem cell characteristics and are exclusively responsible for tumorigenicity. This discovery has led to the development of the stem cell concept of cancer, which proposes that a subpopulation of self-renewing tumor cells, also termed cancer stem cells, is responsible for tumorigenesis and metastasis. This contrasts with the stochastic model of tumor development, which holds that all tumor cells are capable of tumor initiation. Different subpopulations of cancer stem cells have been identified in pancreatic ductal adenocarcinoma, based on the use of combinations of surface markers that allow their isolation, propagation, and further characterization. Importantly, cancer stem cells are not only capable of self-renewal and differentiation, but may also confer virulence via immune system evasion and multidrug resistance, and potentially via vasculogenic mimicry and transition to migratory and metastasizing derivatives. Therapeutic targeting of this subset of cells and the pathways defining their virulence holds great promise for the development of more effective strategies for the amelioration and eradication of this most lethal form of cancer. © 2011 Springer.

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