Improvement of megakaryocytic progenitor culture for toxicological investigations

The aim of this work was to obtain an in vitro test for the evaluation of x enobiotic toxicity on the proliferation and on the differentiation of megak aryocyte progenitors. The rapid rate of blood cell renewal makes the hemato poietic system a susceptible target for xenobiotic toxicity. Hematotoxic mo lecules can affect one or more hematopoietic, lineages leading to blood dis orders. Megakaryocytopoiesis in vitro models applied to toxicological inves tigations needs to be accurate, precise, reproducible, sensitive and specif ic, Human hematopoietic progenitors from umbilical cord blood were seeded i n a collagen medium. Three solvents have been selected (ethanol, methanol, acetone), and one (dimethyl sulfoxide; DMSO) has been eliminated due to its cytotoxicity at tested concentrations. Cryopreservation did not affect the sensitivity of CFU-MK to xenobiotics. An overnight incubation of cell susp ensions as cell suspension enrichment before plating gave better cloning ef ficiency than CD34(+) cells negative selection. Comparison between differen t parameters allowed us to propose a protocol suitable for an in vitro mega karyocytopoiesis model in toxicological investigations. The effects of thre e toxins were studied on CFU-MK development in order to verify the efficien cy of this clonogenic assays for toxicity testing. The CFU-MK culture condi tions defined revealed their usefulness for investigating. drug cytoxicity towards megakaryocytic progenitors and disturbance of their proliferation. (C) 2001 Elsevier Science Ltd. All, rights reserved.