The metastasis inducer CCN1 (CYR61) activates the fatty acid synthase (FASN)-driven lipogenic phenotype in breast cancer cells

The angiogenic inducer CCN1 (Cysteine-rich 61, CYR61) is differentially activated in metastatic breast carcinomas. However, little is known about the precise mechanisms that underlie the pro-metastatic actions of CCN1. Here, we investigated the impact of CCN1 expression on fatty acid synthase (FASN), a metabolic oncogene thought to provide cancer cells with proliferative and survival advantages. Forced expression of CCN1 in MCF-7 cells robustly up-regulated FASN protein expression and also significantly increased FASN gene promoter activity 2- to 3-fold, whereas deletion of the sterol response element-binding protein (SREBP) binding site in the FASN promoter completely abrogated CCN1-driven transcriptional activation. Pharmacological blockade of MAPK or PI-3´K activation similarly prevented the ability of CCN1 to induce FASN gene activation. Pharmacological inhibition of FASN activity with the mycotoxin cerulenin or the small compound C75 reversed CCN1-induced acquisition of estrogen independence and resistance to hormone therapies such as tamoxifen and fulvestrant in anchorage-independent growth assays. This study uncovers FASNdependent endogenous lipogenesis as a new mechanism controlling the metastatic phenotype promoted by CCN1. Because estrogen independence and progression to a metastatic phenotype are hallmarks of therapeutic resistance and mortality in breast cancer, this previously unrecognized CCN1-driven lipogenic phenotype represents a novel metabolic target to clinically manage metastatic disease progression.Fil: Menendez, Javier A.. Instituto Catalán de Oncología; España. Institut d; EspañaFil: Vellón, Luciano. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental. Fundación de Instituto de Biología y Medicina Experimental. Instituto de Biología y Medicina Experimental; ArgentinaFil: Espinoza, Ingrid. University Of Mississippi; Estados UnidosFil: Lupu, Ruth. Mayo Clinic Cancer Center; Estados Unido

Understanding the influence of substrate when growing tumorspheres

Background: Cancer stem cells are important for the development of many solid tumors. These cells receive promoting and inhibitory signals that depend on the nature of their environment (their niche) and determine cell dynamics. Mechanical stresses are crucial to the initiation and interpretation of these signals. Methods: A two-population mathematical model of tumorsphere growth is used to interpret the results of a series of experiments recently carried out in Tianjin, China, and extract information about the intraspecific and interspecific interactions between cancer stem cell and differentiated cancer cell populations. Results: The model allows us to reconstruct the time evolution of the cancer stem cell fraction, which was not directly measured. We find that, in the presence of stem cell growth factors, the interspecific cooperation between cancer stem cells and differentiated cancer cells induces a positive feedback loop that determines growth, independently of substrate hardness. In a frustrated attempt to reconstitute the stem cell niche, the number of cancer stem cells increases continuously with a reproduction rate that is enhanced by a hard substrate. For growth on soft agar, intraspecific interactions are always inhibitory, but on hard agar the interactions between stem cells are collaborative while those between differentiated cells are strongly inhibitory. Evidence also suggests that a hard substrate brings about a large fraction of asymmetric stem cell divisions. In the absence of stem cell growth factors, the barrier to differentiation is broken and overall growth is faster, even if the stem cell number is conserved. Conclusions: Our interpretation of the experimental results validates the centrality of the concept of stem cell niche when tumor growth is fueled by cancer stem cells. Niche memory is found to be responsible for the characteristic population dynamics observed in tumorspheres. The model also shows why substratum stiffness has a deep influence on the behavior of cancer stem cells, stiffer substrates leading to a larger proportion of asymmetric doublings. A specific condition for the growth of the cancer stem cell number is also obtainedFil: Benitez, Lucia. Universidad Nacional de Córdoba. Facultad de Matemática, Astronomía y Física; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Física Enrique Gaviola. Universidad Nacional de Córdoba. Instituto de Física Enrique Gaviola; ArgentinaFil: Barberis, Lucas Miguel. Universidad Nacional de Córdoba. Facultad de Matemática, Astronomía y Física; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Física Enrique Gaviola. Universidad Nacional de Córdoba. Instituto de Física Enrique Gaviola; ArgentinaFil: Vellón, Luciano. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental. Fundación de Instituto de Biología y Medicina Experimental. Instituto de Biología y Medicina Experimental; ArgentinaFil: Condat, Carlos. Universidad Nacional de Córdoba. Facultad de Matemática, Astronomía y Física; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Física Enrique Gaviola. Universidad Nacional de Córdoba. Instituto de Física Enrique Gaviola; Argentin

Functional blockade of α5β1 integrin induces scattering and genomic landscape remodeling of hepatic progenitor cells

<p>Abstract</p> <p>Background</p> <p>Cell scattering is a physiological process executed by stem and progenitor cells during embryonic liver development and postnatal organ regeneration. Here, we investigated the genomic events occurring during this process induced by functional blockade of α₅β₁integrin in liver progenitor cells.</p> <p>Results</p> <p>Cells treated with a specific antibody against α₅β₁integrin exhibited cell spreading and scattering, over-expression of liver stem/progenitor cell markers and activation of the ERK1/2 and p38 MAPKs signaling cascades, in a similar manner to the process triggered by HGF/SF1 stimulation. Gene expression profiling revealed marked transcriptional changes of genes involved in cell adhesion and migration, as well as genes encoding chromatin remodeling factors. These responses were accompanied by conspicuous spatial reorganization of centromeres, while integrin genes conserved their spatial positioning in the interphase nucleus.</p> <p>Conclusion</p> <p>Collectively, our results demonstrate that α₅β₁integrin functional blockade induces cell migration of hepatic progenitor cells, and that this involves a dramatic remodeling of the nuclear landscape.</p

Heregulin drives endocrine resistance by altering il-8 expression in er-positive breast cancer

Sustained HER2/HER3 signaling due to the overproduction of the HER3 ligand heregulin (HRG) is proposed as a key contributor to endocrine resistance in estrogen receptor-positive (ER+) breast cancer. The molecular mechanisms linking HER2 transactivation by HRG-bound HER3 to the acquisition of a hormone-independent phenotype in ER+ breast cancer is, however, largely unknown. Here, we explored the possibility that autocrine HRG signaling drives cytokine-related endocrine resistance in ER+ breast cancer cells. We used human cytokine antibody arrays to semi-quantitatively measure the expression level of 60 cytokines and growth factors in the extracellular milieu of MCF-7 cells engineered to overexpress full-length HRGβ2 (MCF-7/HRG cells). Interleukin-8 (IL-8), a chemokine closely linked to ER inaction, emerged as one the most differentially expressed cytokines. Cytokine profiling using structural deletion mutants lacking both the N-terminus and the cytoplasmic-transmembrane region of HRGβ2—which is not secreted and cannot transactivate HER2—or lacking a nuclear localization signal at the N-terminus—which cannot localize at the nucleus but is actively secreted and transactivates HER2—revealed that the HRG-driven activation of IL-8 expression in ER+ cells required HRG secretion and transactivation of HER2 but not HRG nuclear localization. The functional blockade of IL-8 with a specific antibody inversely regulated ERα-driven transcriptional activation in endocrine-sensitive MCF-7 cells and endocrine-resistant MCF-7/HRG cells. Overall, these findings suggest that IL-8 participates in the HRG-driven endocrine resistance program in ER+/HER2- breast cancer and might illuminate a potential clinical setting for IL8- or CXCR1/2-neutralizing antibodies.Fil: Papadimitropoulou, Adriana. Academy of Athens; GreciaFil: Vellón, Luciano. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental. Fundación de Instituto de Biología y Medicina Experimental. Instituto de Biología y Medicina Experimental; ArgentinaFil: Atlas, Ella. University of Ottawa; CanadáFil: Steen, Travis Vander. Mayo Clinic; Estados UnidosFil: Cuyàs, Elisabet. Institut D'investigació Biomèdica de Girona Dr. Josep Trueta; España. Institut Català d'Oncologia; EspañaFil: Verdura, Sara. Institut Català d'Oncologia; España. Institut D'investigació Biomèdica de Girona Dr. Josep Trueta; EspañaFil: Espinoza, Ingrid. University of Mississippi; Estados UnidosFil: Menendez, Javier A.. Institut Català d'Oncologia; España. Institut D'investigació Biomèdica de Girona Dr. Josep Trueta; EspañaFil: Lupu, Ruth. Mayo Clinic; Estados Unidos. University of Ottawa; Canadá. Mayo Clinic Cancer Center; Estados Unido

Binding of the angiogenic/senescence inducer CCN1/CYR61 to integrin α6β1 drives endocrine resistance in breast cancer cells

CCN1/CYR61 promotes angiogenesis, tumor growth and chemoresistance by binding to its integrin receptor αvβ3 in endothelial and breast cancer (BC) cells. CCN1 controls also tissue regeneration by engaging its integrin receptorα6β1 to induce fibroblast senescence. Here, we explored if the ability of CCN1 to drive an endocrine resistancephenotype in estrogen receptor-positive BC cells relies on interactions with either αvβ3 or α6β1. First, we tookadvantage of site-specific mutagenesis abolishing the CCN1 receptor-binding sites to αvβ3 and α6β1 to determine theintegrin partner responsible for CCN1-driven endocrine resistance. Second, we explored a putative nuclear role ofCCN1 in regulating ERα-driven transcriptional responses. Retroviral forced expression of a CCN1 derivative with asingle amino acid change (D125A) that abrogates binding to αvβ3 partially phenocopied the endocrine resistancephenotype induced upon overexpression of wild-type (WT) CCN1. Forced expression of the CCN1 mutant TM,which abrogates all the T1, H1, and H2 binding sites to α6β1, failed to bypass the estrogen requirement foranchorage-independent growth or to promote resistance to tamoxifen. Wild-type CCN1 promoted estradiol-independent transcriptional activity of ERα and enhanced ERα agonist response to tamoxifen. The α6β1-binding-defective TM-CCN1 mutant lost the ERα co-activator-like behavior of WT-CCN1. Co-immunoprecipitation assaysrevealed a direct interaction between endogenous CCN1 and ERα, and in vitro approaches confirmed the ability ofrecombinant CCN1 to bind ERα. CCN1 signaling via α6β1, but not via αvβ3, drives an endocrine resistance phenotypethat involves a direct binding of CCN1 to ERα to regulate itstranscriptional activity in ER+ BC cells.Fil: Espinoza, Ingrid. University of Mississippi; Estados Unidos. Mayo Clinic ; Estados UnidosFil: Yang, Lin. Mayo Clinic ; Estados UnidosFil: Steen, Travis Vander. Mayo Clinic ; Estados UnidosFil: Vellón, Luciano. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental. Fundación de Instituto de Biología y Medicina Experimental. Instituto de Biología y Medicina Experimental; ArgentinaFil: Cuyàs, Elisabet. Institut D`investigació Biomedica de Girona Dr. Josep Trueta (idib`gi); EspañaFil: Verdura, Sara. Institut D`investigació Biomedica de Girona Dr. Josep Trueta (idib`gi); EspañaFil: Lau, Lester. Institut D`investigació Biomedica de Girona Dr. Josep Trueta (idib`gi); España. University of Illinois; Estados UnidosFil: Menendez, Javier A.. Institut D`investigació Biomedica de Girona Dr. Josep Trueta (idib`gi); EspañaFil: Lupu, Ruth. Institut D`investigació Biomedica de Girona Dr. Josep Trueta (idib`gi); Españ

Progesterone receptor isoform-dependent cross-talk between prolactin and fatty acid synthase in breast cancer

Progesterone receptor (PR) isoforms can drive unique phenotypes in luminal breast cancer (BC). Here, we hypothesized that PR-B and PR-A isoforms differentially modify the cross-talk between prolactin and fatty acid synthase (FASN) in BC. We profiled the responsiveness of the FASN gene promoter to prolactin in T47Dco BC cells constitutively expressing PR-A and PR-B, in the PR-null variant T47D-Y cell line, and in PR-null T47D-Y cells engineered to stably re-express PR-A (T47D-YA) or PR-B (T47D-YB). The capacity of prolactin to up-regulate FASN gene promoter activity in T47Dco cells was lost in T47D-Y and TD47-YA cells. Constitutively up-regulated FASN gene expression in T47-YB cells and its further stimulation by prolactin were both suppressed by the prolactin receptor antagonist hPRL-G129R. The ability of the FASN inhibitor C75 to decrease prolactin secretion was more conspicuous in T47-YB cells. In T47D-Y cells, which secreted notably less prolactin and downregulated prolactin receptor expression relative to T47Dco cells, FASN blockade resulted in an augmented secretion of prolactin and up-regulation of prolactin receptor expression. Our data reveal unforeseen PR-B isoform-specific regulatory actions in the cross-talk between prolactin and FASN signaling in BC. These findings might provide new PR-B/FASN-centered predictive and therapeutic modalities in luminal intrinsic BC subtypesFil: Menendez, Javier A.. Institut Català d'Oncologia; España. Institut d’Investigació Biomèdica de Girona; EspañaFil: Peirce, Susan K.. Clemson University. Pearce Center Professional Communication; Estados UnidosFil: Papadimitropoulou, Adriana. Biomedical Research Foundation Academy of Athens; GreciaFil: Cuyàs, Elisabet. Institut Català d'Oncologia; España. Institut d’Investigació Biomèdica de Girona; EspañaFil: Steen, Travis Vander. Mayo Foundation for Medical Education and Research. Mayo Clinic; Estados UnidosFil: Verdura, Sara. Institut Català d'Oncologia; España. Institut d’Investigació Biomèdica de Girona; EspañaFil: Vellón, Luciano. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental. Fundación de Instituto de Biología y Medicina Experimental. Instituto de Biología y Medicina Experimental; ArgentinaFil: Chen, Wen Y.. Clemson University; Estados UnidosFil: Lupu, Ruth. Mayo Foundation for Medical Education and Research. Mayo Clinic; Estados Unidos. Clemson University; Estados Unidos. Mayo Clinic Cancer Center; Estados Unido

Stem Cell Biobanks for Research

The collection and storage of human tissue samples has been present in medicine for centuries, however, biobanking has recently become a dedicated activity. The technological developments that have allowed the isolation, storage and long term viability of human cells ex vivo, and to obtain relevant scientific information, including genetic information, open tremendous possibilities for advancing biomedical research. At the same time, these possibilities have raised complex ethical issues regarding tissue donors, researchers using samples and society awareness of biobanking as a whole. This article aims to review the operation of stem cell biobanks, related ethical issues and the legal framework in Spain. Special consideration will be given to the new but revolutionary appearance of induced pluripotent stem cells. Most of the topics discussed here will be in the framework of banking adult derived stem cells, which do not entail in themselves any significant ethical dilemma

iPSCs: From Bench to Clinical Bed

Induced pluripotent stem cells (iPSC) have been acknowledged as a milestone in the field of stem cell biology and regenerative medicine, providing an excellent tool to tackle fundamental biological issues regarding reproduction, regeneration, and (de)differentiation at genetic and epigenetic levels, and the valuable cell sources for tissue regeneration, human disease modeling, and drug discovery. Furthermore, iPSC generation with patient-specific somatic cells holds great promise for autologous cell replacement therapy and organ transplantations.Fil: Li, Yuging. University Of Emory; Estados UnidosFil: Park, Changwon. University Of Emory; Estados UnidosFil: Vellón, Luciano. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental. Fundación de Instituto de Biología y Medicina Experimental. Instituto de Biología y Medicina Experimental; ArgentinaFil: Li, Xuekun. Zhejiang University School of Medicine; Chin

Additive apoptotic effect of STI571 with the cytoprotective agent amifostine in K-562 cell line

Purpose: To study the apoptotic effect of the 2-phenylaminopyrimidine derivative STI571 in combination with antioxidant agents on K-562 cell line derived from a Philadelphia chromosome-positive chronic myeloid leukemia patient. Materials and methods: K-562 (BCR/ABL+), U-937, and HL60 (BCR/ABL-) leukemic cell lines were incubated with STI571 and the antioxidant agents catalase, glutathione, superoxide dismutase, and amifostine (AMI). Apoptotic effect was analyzed by morphological and flow cytometric criteria. Results: STI571 at concentrations higher than 0.25 μmol L-1 produced apoptosis (P<0.05) in K-562 cells only after treatment for 72 h. At the mentioned concentrations, STI571 also induced an increase in the loss of mitochondrial transmembrane potential from 24.6 to 40%. Combination of STI571 (0.5 μmol L-1) with antioxidant agents showed that the cytoprotective agent AMI (0.75 mg mL-1) produced an additive effect in the proapoptotic activity of STI571 in K-562 cells at nuclear (58.8%±2.0 vs. 28.9%±3.3) and mitochondrial (53.3%±3.6 vs. 29.5%±1.2) levels. Conclusions: Our results show that only AMI in combination with STI571, at submicromolar concentration, has an additive effect in K-562 cell line, and it does not have severe toxic effects on Philadelphia chromosome negative cells. © Springer-Verlag 2005.Fil: Vellón, Luciano. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Academia Nacional de Medicina de Buenos Aires. Instituto de Investigaciones Hematológicas ; ArgentinaFil: Gonzalez Cid, Marcela Beatriz. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Academia Nacional de Medicina de Buenos Aires. Instituto de Investigaciones Hematológicas ; ArgentinaFil: de Campos Nebel, Ildefonso Marcelo. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Academia Nacional de Medicina de Buenos Aires. Instituto de Investigaciones Hematológicas ; ArgentinaFil: Larripa, Irene Beatriz. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Academia Nacional de Medicina de Buenos Aires. Instituto de Investigaciones Hematológicas ; Argentin

Assessing the distribution of cancer stem cells in tumorspheres

Abstract Cancer Stem Cells presumably drive tumor growth and resistance to conventional cancer treatments. From a previous computational model, we inferred that these cells are not uniformly distributed in the bulk of a tumorsphere. To confirm this result, we cultivated tumorspheres enriched in stem cells, and performed immunofluorescent detection of the stemness marker SOX2 using confocal microscopy. In this article, we present an image processing method that reconstructs the amount and location of the Cancer Stem Cells in the spheroids. Its advantage is the use of a statistical criterion to classify the cells in Stem and Differentiated, instead of setting an arbitrary threshold. Moreover, the analysis of the experimental images presented in this work agrees with the results from our computational models, thus enforcing the notion that the distribution of Cancer Stem Cells in a tumorsphere is non-homogeneous. Additionally, the method presented here provides a useful tool for analyzing any image in which different kinds of cells are stained with different markers