Mode of Action of 5-Bromodeoxyuridine on Mammalian Cells in Culture

Abstract

The effects of 5-bromouracil, an analogue of thymine, have been extensively studied in microbial systems. The incorporation of this analogue into the deoxyribonucleic acid of several strains of bacteria has been demonstrated (l-5). This phenomenon was shown to be associated with morphological changes caused by unbalanced growth (1,2,5), with decrease in viability (1, 5) and with the occurrence of 6-methylaminopurine as a structural part of DNA (2). The deoxyribonucleoside of 5-bromouracil, an analogue of thymidiie, has also been studied in bacterial systems and found to be both an inhibitor (6-8) and a growth factor (8). This compound has been shown to inhibit the incorporation of labeled formaldehyde (Q), formate, erotic acid, and thymidine (10) into DNA-thymine of mammalian tissues in vitro and of labeled formaldehyde into DNA-thymine of spleen and tumor t,issues in u-iuo (9). In the present study, the incorporation of 5-bromodeoxyuridine into DNA of HeLa cells was demonstrated and this phenomenon was shown to be associated with unbalanced growth and loss of viability of the cell. A preliminary report on these findings has been presented (11).