K. Yoshida et al., Mitochondrial genotypes and radiation-induced micronucleus formation in human osteosarcoma cells in vitro, ONCOL REP, 8(3), 2001, pp. 615-619
We investigated whether or not the mitochondrial genotypes affect radiation
-induced micronucleus (MN) formation. For that purpose, the rho (+), KT1 an
d rho (0) human osteosarcoma cell lines were used, which carry the wild-typ
e mitochondrial DNA (mtDNA), the tRNA(Lys) mutant mtDNA and no mtDNA, respe
ctively. Despite no significant difference in the clonogenic radiosensitivi
ty, the rho (+), KT1 and rho (0) cells exhibited high, intermediate and low
radiosensitivities, respectively, to the MN induction in cytokinesis-block
ed binucleated cells. Such differential MN inductions were correlated with
high, intermediate and low levels of cellular ATP in the rho (+), KT1 and r
ho (0) cells, respectively, but not exactly with ROS production. Antimycin
A that inhibits the respiratory complex III reduced the rate of radiation-i
nduced MN induction in the rho (+) and KT1, but not rho (0) cells. Thus, th
e functional status of the mtDNA to produce ATP appears to play a significa
nt role for radiation-induced MN.