S. Paglin et al., RADIATION-INDUCED MICRONUCLEI FORMATION IN HUMAN BREAST-CANCER CELLS - DEPENDENCE ON SERUM AND CELL-CYCLE DISTRIBUTION, Biochemical and biophysical research communications, 237(3), 1997, pp. 678-684
Micronuclei (MN) formation was defined as a form of radiation-induced
damage in MCF-7 cells. MN appeared post-mitosis and were scored in bi-
nucleated cells of cytochalasin B treated cultures. MN were surrounded
by an envelope composed of inner and outer membranes, and contained f
ragmented chromosomes. However, typical features of apoptosis, such as
chromatin margination or condensation were not observed. Reducing ser
um concentration resulted in a decreased MN formation, suggesting that
serum factors directly affected MN formation and/or that serum deplet
ion decreased the availability of radiation sensitive MN-forming cells
for mitosis. Irradiation of G(1) and S phase enriched populations rev
ealed that S phase cells were more prone to MN formation than G(1) cel
ls. Radiation-induced chromosomal aberration can therefore be modulate
d by altering serum level and cell cycle distribution. (C) 1997 Academ
ic Press.