CDCP1 identifies a broad spectrum of normal and malignant stem/progenitor cell subsets of hematopoietic and nonhematopoietic origin.

CUB-domain-containing protein 1 (CDCP1) is a novel transmembrane molecule that is expressed in metastatic colon and breast tumors as well as on the surface of hematopoietic stem cells. In this study, we used multiparameter flow cytometry and antibodies against CDCP1 to analyze the expression of CDCP1 on defined hematopoietic cell subsets of different sources. In addition, CDCP1 expression on leukemic blasts and on cells with nonhematopoietic stem/progenitor cell phenotypes was determined.

Additional transplantation of ex vivo generated megakaryocytic cells after high-dose chemotherapy.

The additional transplantation of ex vivo generated hematopoietic (post)-progenitor cells represents a possible approach to ameliorate high-dose chemotherapy induced cytopenia. We investigated the feasibility of the large-scale expansion and transplantation of autologous megakaryocytic cells in four patients with advanced solid tumors. Up to 1,460x10(6) ex vivo generated cells were administered without adverse effects but no clear cut effect on platelet recovery was observed.

Human plasma thrombopoietin levels are regulated by binding to platelet thrombopoietin receptors in vivo.

Background: Data from several studies support the hypothesis that thrombopoietin (TPO) plasma levels are regulated via circulating platelet (PLT) numbers by binding to PLT TPO receptors (TPO-Rs). In this study, PLT numbers and TPO plasma levels were measured following the transfusion of unmanipulated, sham-saturated, and TPO-R-saturated PLT preparations to provide additional in vivo evidence for this regulatory mechanism.

Study Design And Methods: Following in vitro experiments to characterize pegylated recombinant human megakaryocyte growth and development factor (PEG-rHuMGDF) binding characteristics, PLT numbers and TPO plasma levels were measured following the transfusion of unmanipulated, sham-saturated, and TPO-R-saturated PLT preparations in thrombocytopenic patients.