Sublethal doses of 5-FU inhibit division of O-2A/OPCs. Clonal analysis was used to study the effects of low-dose 5-FU (0.05 μM for 24 h) on the division and differentiation of freshly isolated progenitor cells. O-2A/OPCs were grown at clonal density and exposed one day after plating to (a) vehicle alone or (b) 0.05 μM 5-FU for 24 h, doses that killed less than 5% of O-2A/OPCs in mass culture. The number of undifferentiated O-2A/OPCs and differentiated cells (oligodendrocytes) was determined in each individual clone from a total number of 100 clones in each condition by morphological examination and by immunostaining with A2B5 and anti-GalC antibodies (to label O-2A/OPCs and oligodendrocytes, respectively). Results are presented as three-dimensional graphs. The number of progenitors per clone is shown on the x (horizontal) axis, the number of oligodendrocytes on the z (orthogonal) axis and the number of clones with any particular composition on the y (vertical) axis. In 5-FU-treated cultures analyzed five days after initiating 5-FU exposure, there was an increase in the representation of small clones consisting wholly of oligodendrocytes and clones containing large numbers of oligodendrocytes, a reduction in the representation of large clones, a general shift of clone size towards smaller values, and a clear reduction in the total number of progenitor cells (see text for details). Experiments were performed in triplicate in at least two independent experiments.
Han et al. Journal of Biology 2008 7:12 doi:10.1186/jbiol69