[Mesenchymal stem cells and regenerative medicine: future perspectives in osteoarthritis]

Mesenchymal stromal or stem cells (MSCs) are multipotent adult cells that can be isolated from a variety of adult or neonatal tissues, such as bone marrow, fat tissue, placenta or umbilical cord. A therapy based on MSCs can be justified in osteoarthritis (OA) thanks to their differentiation abilities but mostly, to their paracrine and immunosuppressive properties. Possible therapeutic strategies therefore rely on the articular injection of MSCs suspensions for trophic activity or the implantation of MSCs combined with biodegradable materials for tissue engineering applications. Depending on the mode of administration and behavior after implantation, they can decrease local inflammation, prevent chondrocyte hypertrophy and apoptosis as well as differentiate into cartilage-forming chondrocytes. In this review, we summarize pathophysiological and mechanistic data and discuss perspectives confirming the interest of MSCs as a potential therapeutic strategy in OA.

[Pediatric de novo acute megakaryoblastic leukemia: an affair of complexes]

Pediatric acute megakaryoblastic leukemia (AMKL) are generally associated with poor prognosis and the expression of fusion oncogenes involving transcriptional regulators. Recent results indicate that the ETO2-GLIS2 fusion, associated with 25-30 % of pediatric AMKL, binds and alters the activity of regulatory regions of gene expression, called "enhancers", resulting in the deregulation of GATA and ETS factors essential for the development of hematopoietic stem cells. An imbalance in GATA/ETS factor activity is also found in other AMKL subgroups. This review addresses the transcriptional bases of transformation in pediatric AMKL and therapeutic perspectives.