. . . . . . . . . . "Tissu adipeux -- Greffe" . . . . . "Th\u00E8ses et \u00E9crits acad\u00E9miques" . "Cancer du sein" . . "La Greffe de Tissu Adipeux (GTA) est une technique de reconstruction tissulaire couramment utilis\u00E9e en chirurgie plastique. Cependant, l'innocuit\u00E9 de la GTA dans un contexte post-tumoral demeure incertaine. Suite \u00E0 l'observation au CHU de Nantes d'un cas de r\u00E9cidive locale et tardive d'un ost\u00E9osarcome 13 ans apr\u00E8s la premi\u00E8re tumeur et 18 mois apr\u00E8s une GTA, des \u00E9tudes pr\u00E9cliniques ont \u00E9t\u00E9 r\u00E9alis\u00E9es, identifiant un effet pro-tumoral du TA sur l'ost\u00E9osarcome. Le TA contient de nombreux \u00E9l\u00E9ments pouvant interagir avec des cellules tumorales : adipocytes, Cellules Souches M\u00E9senchymateuses (CSM) ou encore cytokines. Les travaux pr\u00E9sent\u00E9s dans cette th\u00E8se montrent un effet pro-prolif\u00E9ratif des facteurs solubles du TA sur les cellules d'ost\u00E9osarcome ainsi qu'un effet pro-tumoral exerc\u00E9 in vivo et in vitro par les CSM. Apr\u00E8s une GTA, la r\u00E9cidive tumorale peut s'expliquer par la r\u00E9activation de cellules souches canc\u00E9reuses (CSC) r\u00E9siduelles quiescentes. Un mod\u00E8le in vitro de culture en sph\u00E8res a permis d'obtenir des cellules d'ost\u00E9osarcome quiescentes au ph\u00E9notype de CSC. Dans ces conditions, les facteurs solubles produits par le TA et les CSM n'induisaient pas de reprise de la prolif\u00E9ration des cellules tumorales. La GTA post-tumorale \u00E9tant principalement utilis\u00E9e apr\u00E8s un cancer du sein, les travaux ont \u00E9t\u00E9 \u00E9tendus aux cellules de carcinome mammaire. Ainsi les facteurs solubles du TA exercent un effet pro-prolif\u00E9ratif sur les cellules de carcinome mammaire et favorisent la reprise de la prolif\u00E9ration et la Transition \u00C9pith\u00E9lio-M\u00E9senchymateuse (TEM) des cellules tumorales quiescentes." . "Lipofiling or Adipose Tissue Transfer (ATT) is a commonly used procedure in plastic surgery to correct tissue defects. However, the safety of lipofilling used in a post-neoplasic context remains still unclear. Facing an unexpected case of a late and local osteosarcoma recurrence reported by Nantes University Hospital, 13 years after the first tumor treatment and 18 months after the patient received a lipofilling, preclinical studies have been established. Previous experiments performed in our laboratory showed a pro-tumor effect of AT on osteosarcoma. Many components of the AT are known to interact with cancer cells: adipocytes, Mesenchymal Stem Cells (MSC), cytokines and other soluble factors. The work presented here focused on the pro-proliferation effect of soluble factors produced by AT on osteosarcoma cells and on the pro-tumor effect of MSC on osteosarcoma, both in vivo and in vitro. In the case of a recurrence following lipofilling, tumor formation can be explained by quiescent Cancer Stem Cells (CSC) being stimulated by AT injection. Quiescent osteosarcoma cells with CSC characteristics have been obtained with an in vitro model of oncosphere culturing. In this model, AT and MSC soluble components were not able to make cells proliferate again. As lipofilling procedure is mainly used after a breast cancer, experiments have been performed on mammary carcinoma cells. Thus, AT soluble factors exhibited a pro-proliferation effect on growing cells and could promote the proliferation and Epithelial to Mesenchymal Transition (EMT) of quiescent cells." . . . "Cellules souches tumorales -- Dissertation universitaire" . "Impact du transfert de tissu adipeux et de cellules souches m\u00E9senchymateuses sur le risque carcinologique" . . . "Impact du transfert de tissu adipeux et de cellules souches m\u00E9senchymateuses sur le risque carcinologique" . "2015" . . . . . "Impact of adipose tissue and mesenchymal stem cell transfer on carcinological risk" . . "Ost\u00E9osarcome" . "Text" . "Cellules stromales m\u00E9senchymateuses" . .