CFU-s and CFU-c proliferation after treatment of normal bone marrow cells with Ehrlich ascitic fluid.

The possible role of some soluble factor produced by tumor cells or by tumor-host interaction on homeostatic mechanism of normal bone marrow was investigated. Our data show that the in vitro pretreatment of normal bone marrow cells with Ehrlich acellular ascitic fluid (EAF) produces a severe reduction of the number of colonies either in CFU-s (colony-forming unit-spleen assay for pluripotent stem cell compartment) or in CFU-c (colony-forming unit-culture test for granulocytic committed compartment). The differentiation of CFU-s and CFU-c was also affected in respect to the controls. In fact, when normal bone marrow cells were pretreated with EAF the proportion of erythroid colonies deriving from CFU-s changed in favor of the undifferentiated one, while the proportion of pure granulocytic colonies was increased in the CFU-c assay.