Identification of Spectral Modifications Occurring during Reprogramming of Somatic Cells

Recent technological advances in cell reprogramming by generation of induced pluripotent stem cells (iPSC) offer major perspectives in disease modelling and future hopes for providing novel stem cells sources in regenerative medicine. However, research on iPSC still requires refining the criteria of the pluripotency stage of these cells and exploration of their equivalent functionality to human embryonic stem cells (ESC). We report here on the use of infrared microspectroscopy to follow the spectral modification of somatic cells during the reprogramming process. We show that induced pluripotent stem cells (iPSC) adopt a chemical composition leading to a spectral signature indistinguishable from that of embryonic stem cells (ESC) and entirely different from that of the original somatic cells. Similarly, this technique allows a distinction to be made between partially and fully reprogrammed cells. We conclude that infrared microspectroscopy signature is a novel methodology to evaluate induced pluripotency and can be added to the tests currently used for this purpose

Etude de la midkine dans le développement des neuroblastomes et évaluation de l'activité anti-tumorale d'un dominant négatif de la midkine

PARIS-BIUP (751062107) / SudocSudocFranceF

Stratégie antitumorale ciblant les Heparin Binding Growth Factors, par inhibition de leurs propriétés prolifératives et angiogéniques

La pléiotrophine (PTN) et la midkine (MDK) constituent la famille des Heparin Binding Growth Factor (HBGF), et activent la prolifération et l'angiogénèse lors de la tumorigenèse. Nous avons d'abord évalué un inhibiteur de la PTN: le peptide PTN 111-136, dans le modèle du carcinome mammaire. Le peptide s'est avéré être un inhibiteur efficace de la croissance tumorale, in vitro et in vivo. Il inhibe également in vitro la migration et la prolifération de cellules endothéliales humaines. Il agit donc de façon synergique sur deux mécanismes important de la tumorigenèse: la prolifération des cellules tumorales et la néoangiogenèse tumorale. Nous avons ensuite évalué un inhibiteur de la MDK: le peptide MDK 81-121 dans des tumeurs dérivées des crêtes neurales : le neuroblastome et le neurofibrosarcome. Le peptide induit une inhibition de la prolifération des cellules endothéliales et de l'angiogénèse intratumorale, et une inhibition de la prolifération des cellules tumorales in vitro et in vivo.Pleiotrophin (PTN) and Midkine belong to the Heparin Binding Growth Factors (HBGF) family, and are known to promote cells proliferation and angiogenesis along tumorigenesis process. We first evaluated a PTN inhibitor: the PTN 111-136 peptide, in breast cancer model. This peptide appeared to be an efficient inhibitor of tumor growth in vitro and in vivo. It is also able to inhibit in vitro the proliferation and migration of human endothelial cells. This peptide acts on two different important steps of angiogenesis : tumor cells proliferation, and tumor angiogenesis. We then evaluated a MDK inhibtor: the MDK 81-121 peptide, in tumors derived from neural crests: neuroblastoma and neurofibrosarcoma. The peptide induces the inhibition of endothelial cells proliferations, and of tumoral angiogenesis, and also inhibits tumor cells proliferation in vitro and in vivo.PARIS5-BU Méd.Cochin (751142101) / SudocSudocFranceF

Inhibition de l'angiogénèse tumorale par transfert de gènes angiostatiques associés ou non à une chimiothérapie

PARIS7-Bibliothèque centrale (751132105) / SudocSudocFranceF

Generation of induced pluripotent stem cell (iPSC) line from a patient with triple negative breast cancer with hereditary exon 17 deletion of BRCA1 gene

BRCA1 germline mutation confers hereditary predisposition for breast and ovarian cancer. To understand the physiopathology of mammary and ovarian epithelial cancer transformation, and to identify early driver molecular events, we have generated an iPSC line from a patient carrying a germline exon 17 deletion in BRCA1 gene (BRAC1Ex17 iPSC) in a high-risk family context. Blood cells were reprogrammed used non-integrative virus of Sendaï. The BRCA1-deleted iPSC had normal karyotype, harboured a deletion in the exon 17 of the BRCA1 gene, expressed pluripotent hallmarks and had the differentiation capacity into the three germ layers

Generation of an induced pluripotent stem cell (iPSC) line from a patient with maturity-onset diabetes of the young type 13 (MODY13) with a the potassium inwardly-rectifying channel, subfamily J, member 11 (KCNJ11) mutation

Heterozygous activating mutation (p.Glu227Lys) in KCNJ11 leads to maturity-onset diabetes of the young (MODY) type 13, that is a subtype of dominant inherited young-onset non-autoimmune diabetes due to a primary defect in pancreatic beta cells. We generated induced pluripotent stem cells (iPSCs) from a patient with KCNJ11p.Glu227Lys mutation who developed MODY at 13 years old. KCNJ11p.Glu227Lys-mutated cells that were reprogrammed by non-integrative viral transduction had normal karyotype, harboured the KCNJ11p.Glu227Lys mutation, expressed pluripotency hallmarks and had the differentiation capacity into the three germ layers