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Highlights d The Striga genome reflects a three-phase model of parasitic plant genome evolution d A family of strigolactone receptors has undergone a striking expansion in Striga d Genes in lateral root development are coordinately induced in a parasitic organ d Host genes and retrotransposons are horizontally transferred into Striga

Acute myelogenous leukemia (AML) is a heterogeneous disorder characterized by clonal proliferation of stem cell-like blasts in bone marrow (BM); however, their unique cellular interaction within the BM microenvironment and its functional significance remain unclear. Here, we assessed the BM microenvironment of AML patients and demonstrate that the leukemia stem cells induce a change in the transcriptional programming of the normal mesenchymal stromal cells (MSC). The modified leukemic niche alters the expressions of cross-talk molecules (i.e., CXCL12 and JAG1) in MSCs to provide a distinct cross-talk between normal and leukemia cells, selectively suppressing normal primitive hematopoietic cells while supporting leukemogenesis and chemoresistance. Of note, AML patients exhibited distinct heterogeneity in the alteration of mesenchymal stroma in BM. The distinct pattern of stromal changes in leukemic BM at initial diagnosis was associated with a heterogeneous posttreatment clinical course with respect to the maintenance of complete remission for 5 to 8 years and early or late relapse. Thus, remodeling of mesenchymal niche by leukemia cells is an intrinsic self-reinforcing process of leukemogenesis that can be a parameter for the heterogeneity in the clinical course of leukemia and hence serve as a potential prognostic factor. Cancer Res; 75(11); 2222-31. Ó2015 AACR.

When large engineered tissue structures are used to achieve tissue regeneration, formation of vasculature is an essential process. We report a technique that combines 3D printing with spatial and temporal control of dual growth factors to prevascularize bone tissue. Human dental pulp stem cells (DPSCs) that have both osteogenic and vasculogenic potential were printed with bone morphogenetic protein-2 (BMP-2) in the peripheral zone of the 3D printed construct, and with the vascular endothelial growth factor (VEGF) in the central zone, in which a hypoxic area forms. The structure was implanted in the back of a mouse and tissue regeneration was assessed after 28 d. Microvessels were newly formed in the hypoxic area of the printed large volume structure, and angiogenesis from the host tissue was also observed. Bone regeneration was faster in prevascularized structures than in nonvascularized structures. The 3D-printed prevascularized structure could be a promising approach to overcome the size limitation of tissue implants and to enhance bone regeneration.