title: Induction of pluripotent stem cells from adult somatic cells by protein-based dedifferentiation

status: Public on Dec 02 2008

city: Seoul

first: Hyun-Jai

last: Cho

address: 28 Yongon-Dong, Jongno-gu

department: Division of Cardiology, Department of Internal Medicine

country: South Korea

institute: Seoul National University Hospital

summary: The concept of dedifferentiation of somatic cells into pluripotent stem cells has opened a new era in regenerative medicine. Viral transduction of defined factors has successfully achieved pluripotency derived from somatic cells. However, during the generation process of induced pluripotent stem (iPS) cells, genetic integration of certain factors may cause mutagenesis or tumorigenicity, which limits further application. Therefore, there is currently ongoing an extensive search for new methods such as transient gene delivery and oocyte-free and non-viral inducers like small molecules. Here we show that the transient delivery of embryonic stem (ES) cell-derived soluble proteins enables dedifferentiation of mouse adult somatic cells converting them into pluripotent stem cells without the introduction of certain transcription factors or genetic manipulation. During the dedifferentiation, global gene expression patterns and epigenetic status were converted from the somatic to the ES-equivalent status. Dedifferentiated somatic cells were morphologically, biologically and functionally indistinguishable from ES cells. Furthermore, the dedifferentiated cells possessed in vivo differentiation and development potential. Our results provide an alternative and safe strategy for dedifferentiation of somatic cells that can be used to facilitate pluripotent stem cell-based cell therapy.

overall_design: Total RNA from mES cell (triplicate), adult fibroblast (triplicate), or dedifferentiated adult fibroblast was isolated. Samples were hybridized to a Affymetrix Mouse Gene 1.0 ST Array according to the manufacturer's protocol. After hybridization, the chips were stained and washed in a Genechip Fluidics Station 450(Affymetrix) and scanned by using a Genechip Array scanner 3000 7G (Affymetrix).

first: Choon-Soo

first: Yoo-Wook

last: Kwon

first: Jae-Seung

last: Paek

first: Sun-Young

last: Jo

first: Jin

last: Hur

first: Eun-Ju

first: Hyun-Jae

last: Kang

first: Young-Bae

last: Park

first: Hyo-Soo

last: Kim


title: Anaplastic Lymphoma Kinase signature

status: Public on Nov 22 2006

city: Torino

first: Roberto

last: Piva

address: Via Santena 7

department: Department of Pathology and CeRMS

country: Italy

institute: University of Torino

summary:
Anaplastic Large Cell Lymphomas (ALCL) represent a subset of lymphomas in which the Anaplastic Lymphoma Kinase (ALK) gene is frequently fused to the NPM gene. We previously demonstrated that the constitutive phosphorylation of ALK chimeric proteins is sufficient to induce cellular transformation in vitro and in vivo, and that ALK activity is strictly required for the survival of ALK positive ALCL cells. To elucidate the signaling pathways required for ALK-mediated transformation and tumor maintenance, we analyzed the transcriptomes of multiple ALK positive ALCL cell lines abrogating their ALK-mediated signaling by inducible ALK RNA interference (RNAi) or with potent and cell permeable ALK inhibitors. Transcripts derived from the gene expression profiling (GEP) analysis uncovered a reproducible signature, which included a novel group of ALK-regulated genes. Functional RNAi screening on a set of these ALK transcriptional targets revealed that the transcription factor C/EBPb and the anti-apoptotic protein BCL2A1 are absolutely necessary to induce cell transformation and/or to sustain the growth and survival of ALK positive ALCL cells. Thus, we proved that an experimentally controlled and functionally validated GEP analysis represents a powerful tool to identify novel pathogenetic networks and validate biologically suitable target genes for therapeutic interventions.
Keywords: other

overall_design: This series of microarray experiments contains the gene expression profiles of Anaplastic Large Cell Lymphoma (ALCL) cell lines (TS [a subclone of Sup-M2] and Su-DHL1) engineered to express ALK-A5 shRNA under a doxycycline-inducible promoter or treated with cell permeable pyrrolocarbazole-derived ALK inhibitors. A mutated ALK-A5M shRNA was used as control. Briefly, cells were transduced with pLV-DsRed-tTRKRAB, expanded, and used for transduction with pLVTH-GFP-shRNA lentiviral particles. Cells were induced with doxycycline (1 microg/ml) for 12 hours, double GFP+ DsRed+ cells selected by fluorescence-activated cell sorting. Cells expressing GFP in the absence of the inducer were removed by a second flow cytometry sorting, and expanded. shRNA expression was induced by doxycycline treatment for 72 or 84 hours. Drug treatments (300 nM), were performed in TS cells with ALK inhibitors (A2 or A3), mock compound (A1), or control diluent for 6 hours. 5 micrograms of total RNA was processed and hybridized to the Affymetrix HG-U133A chip following the manufacturer's instructions.

first: Elisa

last: Pellegrino

first: Michela

last: Mattioli

first: Luca

last: Agnelli

first: Luigia

last: Lombardi

first: Francesco

last: Boccalatte

first: Giulia

last: Costa

first: Bruce

middle: A

last: Ruggeri

first: Mengeng

last: Cheng

last: Chiarle

first: Giorgio

last: Palestro

first: Antonino

last: Neri

last: Inghirami


title: Gene expression analysis of Peripheral T-cell Lymphoma/Unspecified

status: Public on Dec 25 2006

city: bologna

first: pier paolo

last: piccaluga

address: via massarenti 9

institute: university of bologna

summary:
Peripheral T-cell lymphoma unspecified (PTCL/U), the most common form of PTCL, displays heterogeneous morphology and phenotype, poor response to treatment, and dismal prognosis. We demonstrate that PTCL/U shows a gene expression profile clearly distinct from that of normal T-cells. Comparison with the profiles of purified T-cell subpopulations [CD4+, CD8+, resting (HLA-DR-), and activated (HLA-DR+)] reveals that PTCLs/U are most closely related to activated peripheral T-lymphocytes, either CD4+ or CD8+. Interestingly, the global gene expression profile cannot be surrogated by routine CD4/CD8 immunohistochemistry. When compared with normal T-cells, PTCLs/U display deregulation of functional programs often involved in tumorigenesis (e.g. apoptosis, proliferation, cell adhesion, and matrix remodeling). Products of deregulated genes can be detected in PTCLs/U by immunohistochemistry with an ectopic, paraphysiologic or stromal location. Among others, PTCLs/U aberrantly express PDGFRA, a tyrosine-kinase receptor, whose deregulation is often related to a malignant phenotype. Notably, both phosphorylation of PDGFRA and sensitivity of cultured PTCL cells to imatinib (as well as to an inhibitor of histone-deacetylase) are found. These results, which might be extended to other rarer PTCL categories, are provided with implications for tumor pathogenesis and clinical management.
Keywords: Molecular pathogenesis, molecular classification

overall_design: 40 cases of Peripheral T-cell lymphoma (PTCL) were analyzed, including 28 PTCL/unspecified, 6 angioimmunoblastic (AITL) and 6 anaplastic large cell lymphoma cases (ALCL). Frozen lymph-nodes  collected at diagnosis (before therapy) were used. In addition, 20 samples of normal T-cells (5 CD4+, 5 CD8+, 5 HLA-DR+, and 5 HLA-DR-) collected from peripheral blood and tonsils of healthy donors were studied. The HG U133 2.0 plus microarray (Affymetrix) was adopted.

first: Pier-Paolo

last: Piccaluga

first: Stefano

last: Pileri

first: Riccardo

last: Dalla-Favera