@article {505, title = {Mammosphere formation in breast carcinoma cell lines depends upon expression of E-cadherin.}, journal = {PLoS One}, volume = {8}, year = {2013}, month = {2013}, pages = {e77281}, abstract = {

Tumors are heterogeneous at the cellular level where the ability to maintain tumor growth resides in discrete cell populations. Floating sphere-forming assays are broadly used to test stem cell activity in tissues, tumors and cell lines. Spheroids are originated from a small population of cells with stem cell features able to grow in suspension culture and behaving as tumorigenic in mice. We tested the ability of eleven common breast cancer cell lines representing the major breast cancer subtypes to grow as mammospheres, measuring the ability to maintain cell viability upon serial non-adherent passage. Only MCF7, T47D, BT474, MDA-MB-436 and JIMT1 were successfully propagated as long-term mammosphere cultures, measured as the increase in the number of viable cells upon serial non-adherent passages. Other cell lines tested (SKBR3, MDA-MB-231, MDA-MB-468 and MDA-MB-435) formed cell clumps that can be disaggregated mechanically, but cell viability drops dramatically on their second passage. HCC1937 and HCC1569 cells formed typical mammospheres, although they could not be propagated as long-term mammosphere cultures. All the sphere forming lines but MDA-MB-436 express E-cadherin on their surface. Knock down of E-cadherin expression in MCF-7 cells abrogated its ability to grow as mammospheres, while re-expression of E-cadherin in SKBR3 cells allow them to form mammospheres. Therefore, the mammosphere assay is suitable to reveal stem like features in breast cancer cell lines that express E-cadherin.

}, keywords = {Breast Neoplasms, Cadherins, Cell Line, Tumor, Cell Proliferation, Cluster Analysis, Female, gene expression, Gene Expression Profiling, Gene Expression Regulation, Neoplastic, Gene Knockdown Techniques, Humans, MCF-7 Cells, Neoplastic Stem Cells, Spheroids, Cellular, Tumor Cells, Cultured}, issn = {1932-6203}, doi = {10.1371/journal.pone.0077281}, author = {Manuel Iglesias, Juan and Beloqui, Izaskun and Garcia-Garcia, Francisco and Leis, Olatz and Vazquez-Martin, Alejandro and Eguiara, Arrate and Cufi, Silvia and Pavon, Andres and Menendez, Javier A and Dopazo, Joaquin and Martin, Angel G} } @article {516, title = {IL1β induces mesenchymal stem cells migration and leucocyte chemotaxis through NF-κB.}, journal = {Stem Cell Rev Rep}, volume = {8}, year = {2012}, month = {2012 Sep}, pages = {905-16}, abstract = {

Mesenchymal stem cells are often transplanted into inflammatory environments where they are able to survive and modulate host immune responses through a poorly understood mechanism. In this paper we analyzed the responses of MSC to IL-1β: a representative inflammatory mediator. Microarray analysis of MSC treated with IL-1β revealed that this cytokine activateds a set of genes related to biological processes such as cell survival, cell migration, cell adhesion, chemokine production, induction of angiogenesis and modulation of the immune response. Further more detailed analysis by real-time PCR and functional assays revealed that IL-1β mainly increaseds the production of chemokines such as CCL5, CCL20, CXCL1, CXCL3, CXCL5, CXCL6, CXCL10, CXCL11 and CX(3)CL1, interleukins IL-6, IL-8, IL23A, IL32, Toll-like receptors TLR2, TLR4, CLDN1, metalloproteins MMP1 and MMP3, growth factors CSF2 and TNF-α, together with adhesion molecules ICAM1 and ICAM4. Functional analysis of MSC proliferation, migration and adhesion to extracellular matrix components revealed that IL-1β did not affect proliferation but also served to induce the secretion of trophic factors and adhesion to ECM components such as collagen and laminin. IL-1β treatment enhanced the ability of MSC to recruit monocytes and granulocytes in vitro. Blockade of NF-κβ transcription factor activation with IκB kinase beta (IKKβ) shRNA impaired MSC migration, adhesion and leucocyte recruitment, induced by IL-1β demonstrating that NF-κB pathway is an important downstream regulator of these responses. These findings are relevant to understanding the biological responses of MSC to inflammatory environments.

}, keywords = {Cell Adhesion, Cell Movement, Cell Proliferation, Chemokines, Chemotaxis, Leukocyte, Collagen, Fibronectins, Gene Expression Profiling, Gene Knockdown Techniques, HEK293 Cells, Humans, I-kappa B Kinase, Inflammation Mediators, Intercellular Signaling Peptides and Proteins, Interleukin-1beta, Laminin, Leukocytes, Mesenchymal Stem Cells, NF-kappa B, Oligonucleotide Array Sequence Analysis, RNA Interference, Signal Transduction}, issn = {2629-3277}, doi = {10.1007/s12015-012-9364-9}, author = {Carrero, Rub{\'e}n and Cerrada, Inmaculada and Lled{\'o}, Elisa and Dopazo, Joaquin and Garcia-Garcia, Francisco and Rubio, Mari-Paz and Trigueros, C{\'e}sar and Dorronsoro, Akaitz and Ruiz-Sauri, Amparo and Montero, Jos{\'e} Anastasio and Sep{\'u}lveda, Pilar} } @article {531, title = {Early peroxisome proliferator-activated receptor gamma regulated genes involved in expansion of pancreatic beta cell mass.}, journal = {BMC Med Genomics}, volume = {4}, year = {2011}, month = {2011 Dec 30}, pages = {86}, abstract = {

BACKGROUND: The progression towards type 2 diabetes depends on the allostatic response of pancreatic beta cells to synthesise and secrete enough insulin to compensate for insulin resistance. The endocrine pancreas is a plastic tissue able to expand or regress in response to the requirements imposed by physiological and pathophysiological states associated to insulin resistance such as pregnancy, obesity or ageing, but the mechanisms mediating beta cell mass expansion in these scenarios are not well defined. We have recently shown that ob/ob mice with genetic ablation of PPARγ2, a mouse model known as the POKO mouse failed to expand its beta cell mass. This phenotype contrasted with the appropriate expansion of the beta cell mass observed in their obese littermate ob/ob mice. Thus, comparison of these models islets particularly at early ages could provide some new insights on early PPARγ dependent transcriptional responses involved in the process of beta cell mass expansion

RESULTS: Here we have investigated PPARγ dependent transcriptional responses occurring during the early stages of beta cell adaptation to insulin resistance in wild type, ob/ob, PPARγ2 KO and POKO mice. We have identified genes known to regulate both the rate of proliferation and the survival signals of beta cells. Moreover we have also identified new pathways induced in ob/ob islets that remained unchanged in POKO islets, suggesting an important role for PPARγ in maintenance/activation of mechanisms essential for the continued function of the beta cell.

CONCLUSIONS: Our data suggest that the expansion of beta cell mass observed in ob/ob islets is associated with the activation of an immune response that fails to occur in POKO islets. We have also indentified other PPARγ dependent differentially regulated pathways including cholesterol biosynthesis, apoptosis through TGF-β signaling and decreased oxidative phosphorylation.

}, keywords = {Animals, Cell Proliferation, Cell Survival, Cholesterol, Down-Regulation, Female, Gene Expression Regulation, Gene Knockout Techniques, Insulin Resistance, Insulin-Secreting Cells, Mice, obesity, Oxidation-Reduction, Phosphorylation, PPAR gamma, Signal Transduction, Transcription, Genetic, Transforming Growth Factor beta}, issn = {1755-8794}, doi = {10.1186/1755-8794-4-86}, author = {Vivas, Yurena and Martinez-Garcia, Cristina and Izquierdo, Adriana and Garcia-Garcia, Francisco and Callejas, Sergio and Velasco, Ismael and Campbell, Mark and Ros, Manuel and Dopazo, Ana and Dopazo, Joaquin and Vidal-Puig, Antonio and Medina-Gomez, Gema} }