Protease inhibitors reduce the frequency of spontaneous chromosome abnormalities in cells from patients with Bloom syndrome.

Bloom syndrome is an autosomal recessive genetic disease. Cells from patients with this disease are characterized by high levels of chromosome aberrations and sister chromatid exchanges. We show here that the frequency of these chromosomal changes is markedly reduced when the cells are grown in the presence of certain protease inhibitors. In relation to other published data, our results suggest that the primary defect of Bloom syndrome cells may be related to the production of abnormally large amounts of agents, presumably active oxygen species, which are capable of acting like tumor promoters.