Search

Background. Extremely low gestational age neonates (ELGAN, i.e., neonates born before 28 weeks of gestation), are at high risk of developing retinopathy of prematurity (ROP), with potential long-life visual impairment. Due to concomitant anemia, ELGANs need repeated red blood cell (RBC) transfusions. These produce a progressive replacement of fetal hemoglobin (HbF) by adult hemoglobin (HbA). Furthermore, a close association exists between low levels of HbF and severe ROP, suggesting that a perturbation of the HbF-mediated oxygen release may derange retinal angiogenesis and promote ROP. Methods/design. BORN (umBilical blOod to tRansfuse preterm Neonates) is a multicenter double-blinded randomized controlled trial in ELGANs, to assess the effect of allogeneic cord blood RBC transfusions (CB-RBCs) on severe ROP development. Recruitment, consent and randomization take place at 10 Neonatology Intensive Care Units (NICUs) of 8 Italian tertiary Hospitals. ELGANs with gestational age at birth comprised between 24 + 0 and 27 + 6 weeks are randomly allocated into two groups: 1) standard RBC transfusions (adult-RBCs) (control arm); 2) CB-RBCs (intervention arm). In case of transfusion need, enrolled patients receive transfusions according to the allocation arm, unless an ABO/RhD CB-RBC is unavailable. Nine Italian public CB banks cooperate to make available a suitable amount of CB-RBC units for all participating NICUs. The primary outcome is the incidence of severe ROP (stage 3 or higher) at discharge or 40 weeks of post-menstrual age, which occurs first. Discussion. BORN is a ground-breaking trial, pioneering a new transfusion approach dedicated to ELGANs at high risk for severe ROP. In previous non-randomized trials, this transfusion approach was proven feasible and able to prevent the HbF decrease in patients requiring multiple transfusions. Should the BORN trial confirm the efficacy of CB-RBCs in reducing ROP severity, this transfusion strategy would became the preferential blood product to be used in severely preterm neonates. Trial registration: ClinicalTrials.gov Identifier: NCT05100212

Tumor progression is deeply influenced by epi- genetic changes induced by tumor stroma. Cancer- associated fibroblasts (CAFs) have been reported to promote epithelial-mesenchymal transition in cancer cells, thereby enhancing their aggressiveness and stem-like properties. As CAFs are able to recruit endothelial progenitor cells (EPCs) to tumor site, we aim to investigate their interplay for prostate carcinoma progression. Both prostate CAFs and cancer cells actively recruit EPCs, known to affect tumor progression through increased vasculogenesis. EPCs syner- gize with CAFs to further promote epigenetic plasticity of cancer cells, through a mesenchymal-to-amoeboid transi- tion. Indeed, after fibroblasts have engaged epithelial-mes- enchymal transition in cancer cells, a further shift towards amoeboid motility is promoted by EPCs through contact- mediated triggering of the bidirectional ephrinA1/EphA2 signaling. The activation of ephrinA1 reverse pathway enhances EPC-induced neo-vascularization, thus promoting tumor growth, while EphA2 forward signaling elicits mes- enchymal-amoeboid transition in cancer cells, favoring their adhesion to endothelium, transendothelial migration, and lung metastatic colonization. We therefore underscore that the metastatic advantage given by tumor microenviron- ment embraces different motility strategies and propose EphA2-targeted tools as useful adjuvants in anti-metastatic treatments.

Endothelial urokinase-type plasminogen activator receptor (uPAR) is thought to provide a regulatory mechanism in angiogenesis. Here we studied the proangiogenic role of uPAR in endothelial colony-forming cells (ECFCs), a cell population identified in human umbilical blood that embodies all of the properties of an endothelial progenitor cell matched with a high proliferative rate. By using caveolae-disrupting agents and by caveolin-1 silencing, we have shown that the angiogenic properties of ECFCs depend on caveolae integrity and on the presence of full-length uPAR in such specialized membrane invaginations. Inhibition of uPAR expression by antisense oligonucleotides promoted caveolae disruption, suggesting that uPAR is an inducer of caveolae organization. Vascular endothelial growth factor (VEGF) promoted accumulation of uPAR in ECFC caveolae in its undegraded form. We also demonstrated that VEGF-dependent ERK phosphorylation required integrity of caveolae as well as caveolar uPAR expression. VEGF activity depends on inhibition of ECFC MMP12 production, which results in impairment of MMP12-dependent uPAR truncation. Further, MMP12 overexpression in ECFC inhibited vascularization in vitro and in vivo. Our data suggest that intratumor homing of ECFCs suitably engineered to overexpress MMP12 could have the chance to control uPAR-dependent activities required for tumor angiogenesis and malignant cells spreading.

The human mesenchymal stromal cell (hMSC), a type of adult stem cell with a fibroblast-like appearance, has the potential to differentiate along the mesenchymal lineage and also along other cell lineages. These abilities make hMSC a promising candidate for use in regenerative medicine. As the hMSC represents a very rare population in vivo, in vitro expansion is necessary for any clinical use. hMSC characterization is commonly carried out through the expression of specific markers and by the capability of differentiating toward at least adipo-, osteo- and chondrocytic lineages. Commitment processes also result in significant changes in the ultrastructure in order to acquire new functional abilities; however, few studies have dealt with the ultrastructural characteristics of hMSC according to the time of incubation and type of media.The immunophenotype, functional characteristics and ultrastructural features of bone marrow (BM) hMSC cultured in two different media were investigated. The media chosen were Iscove's modified Dulbecco's medium (IMDM) and the Dulbecco's modified Eagle medium (DMEM). The latter has been recommended recently by two international transplantation and cytotherapy societies, the International Society of Cellular Therapy (ISCT) and European Group for Blood and Bone Marrow Transplantation (EBMT), for hMSC expansion for clinical applications.The present results indicate that culture conditions greatly influence hMSC ultrastructural features, proliferation, growth and differentiation. In particular, our findings demonstrate that DMEM preserves the hMSC stem features better. Furthermore, the results obtained in IMDM suggest that a small size does not always correlate with conditions of cell immaturity and a greater proliferative potential.