Characteristics of myeloid differentiation and maturation pathway derived from human hematopoietic stem cells exposed to different linear energy transfer radiation types.

Exposure of hematopoietic stem/progenitor cells (HSPCs) to ionizing radiation causes a marked suppression of mature functional blood cell production in a linear energy transfer (LET)- and/or dose-dependent manner. However, little information about LET effects on the proliferation and differentiation of HSPCs has been reported. With the aim of characterizing the effects of different types of LET radiations on human myeloid hematopoiesis, in vitro hematopoiesis in Human CD34(+) cells exposed to carbon-ion beams or X-rays was compared.

Terminal maturation of megakaryocytes and platelet production by hematopoietic stem cells irradiated with heavy-ion beams.

Hematopoietic processes, especially megakaryocytopoiesis and thrombopoiesis, are highly sensitive to high-linear energy transfer (LET) radiations such as heavy-ion beams that have greater biological effects than low-LET radiation. This study examined the terminal maturation of megakaryocytes and platelet production derived from hematopoietic stem cells irradiated with heavy-ion beams. CD34(+) cells derived from human placental/umbilical cord blood were exposed to monoenergetic carbon-ion beams (LET  =  50 keV/µm) and then cultured in a serum-free medium supplemented with thrombopoietin and interleukin-3.

Heavy ion beam irradiation regulates the mRNA expression in megakaryocytopoiesis from human hematopoietic stem/progenitor cells.

Heavy ion beams are a high-LET radiation that has greater biological effect than electron beams or X-rays. However, little is known about the effect of heavy ion beams on the proliferation and differentiation of human hematopoietic stem/progenitor cells (HSPCs). The present study examined the effect of heavy ion beams on gene expression in human HSPCs, especially during early stage of megakaryocytopoiesis.

Heavy-ion-induced mutations in the gpt delta transgenic mouse: effect of p53 gene knockout.

The influence of the loss of p53 gene on heavy-ion-induced mutations was examined by constructing a new line of transgenic mice, p53 knockout (p53(-/-)) gpt delta. In this mouse model, deletions in lambda DNA integrated into the mouse genome are preferentially selected as Spi(-) phages, which can then be subjected to molecular analysis. Mice were exposed to 10 Gy of whole-body carbon-ion irradiation.