In vitro studies of haematopoietic colony-forming capacity of human fetal liver cells at exposure to cytotoxic and immunomodulatory drugs.

OBJECTIVE

Intrauterine transplantation with haematopoietic stem cells (SC) as a treatment for immunological, haematological and metabolic inherited disorders has not been effective in fetuses with a normal immunological status. Inhibition of the fetal haematopoiesis or immunosuppression might therefore be a therapeutic alternative in fetal SC transplantation. The aim of the present study was to evaluate the effects of drugs that might be considered as therapeutic options in fetal transplantations on the colony-forming capacity of fetal haematopoietic SC.

METHODS

Fetal liver cells were incubated with doxorubicin, daunorubicin, antithymocyte-globulin (ATG), OKT-3 (Orthoclone) and betamethasone. The effects of these drugs on colony formation by fetal hematopoietic SC were evaluated. Colony-forming capacity assays were cultured during 10 days after drug incubation on day 1 and evaluated for differences in number of colonies compared to unexposed cells. For betamethasone, similar studies were performed with adult bone marrow.

RESULTS

A significant reduction in fetal liver haematopoietic colony formation of BFU-E, CFU-GM and CFU- GEMM was detected when 0.1 M doxorubicin (p < 0.05) and 0.5 microM daunorubicin (p < 0.05) were added. OKT-3 (5 microg/ml) and ATG (4 microg/ml) significantly reduced BFU-E, CFU-GM and CFU-GEMM (p < 0.05). A concentration of 0.2 microg/ml betamethasone caused a significant reduction of BFU-E, CFU-GM and CFU-GEMM (p < 0.05).

CONCLUSIONS

The drugs investigated in this in vitro study were capable to different degrees to decrease the colony-forming capacity of fetal haematopoietic progenitor cells. Whether this strategy will become an alternative in fetal SC transplantations is an open question and further studies are required to elucidate the potential use of these drugs in fetal transplantation.