Cigarette smoke potentiates the DNA-damaging effect of manmade mineral fibers.

Epidemiological and experimental studies suggest that manmade mineral fibers (MMMFs) have DNA-damaging and carcinogenic properties. To investigate the hypothesis that cigarette smoke can potentiate MMMF-induced DNA damage, we exposed isolated calf thymus DNA to cigarette smoke condensate and/or three different types of MMMFs: rockwool, glasswool, and ceramic fibers. As an index of DNA damage, the hydroxyl radical-generated formation of 8-hydroxydeoxyguanosine (8OHdG) from deoxyguanosine (dG) was used. All the three fiber types, as well as cigarette smoke condensate alone, caused hydroxylation of dG residues in DNA, and, when smoke was combined with each of the different fibers, rockwool caused a synergistically increased formation of 8OHdG. We suggest that 1) iron-containing MMMFs such as rockwool are able to enhance synergistically cigarette smoke-induced DNA-damage and 2) this damage is caused by hydroxyl radicals.