Mutations induced in a shuttle vector plasmid exposed to monofunctionally activated mitomycin C

✍ Scribed by Alexander E. MacCubbin; Anuradha Mudipalli; Srikanth S. Nadadur; Noreen Ersing; Hira L. Gurtoo

• Book ID: 101264450
• Publisher: John Wiley and Sons
• Year: 1997
• Tongue: English
• Weight: 151 KB
• Volume: 29
• Category: Article
• ISSN: 0893-6692
• DOI: 10.1002/(sici)1098-2280(1997)29:2<143::aid-em5>3.0.co;2-f

✦ Synopsis

Reductive activation of mitomycin C leads to its co-guanine. When pSP189 was exposed to monofuncvalent binding to DNA, forming monoadducts and tionally activated mitomycin C, increases in adduct cross-links. The cytotoxicity of mitomycin C has been levels and mutation frequency were found to be reattributed to cross-link formation, whereas monoad-lated to mitomycin C concentration. The majority ducts are assumed to cause mutagenicity. We have of the mutations involved single bases, with base developed a 32 P-postlabeling technique to measure substitutions making up 59.1% of the total mutations mitomycin C DNA adducts. Using this technique, observed. Of the base substitutions, 67.2% were we have measured monoadduct formation in the transversions and 32.8% were transitions, with shuttle vector plasmid pSP189 and have deter-nearly 80% of all base substitutions involving G:C mined mutations induced by monoadduct forma-base pairs. Deletions, either as single bases or large tion. The shuttle vector plasmid was incubated with deletions, also involved G:C base pairs the majority mitomycin C under conditions favoring monofunc-of the time. The observed bias of mutations at tional activation of mitomycin C. The plasmid was G:C and the formation of a mitomycin C/DNA then replicated in human Ad293 cells, rescued in monoadduct involving guanine suggests that monobacteria, and analyzed for mutations in the supF adduct formation may be responsible for the muta-tRNA gene sequence of pSP189. One major mito-tions. Environ. Mol. Mutagen. 29:143-151, mycin C/DNA adduct was observed by 32 P-postla-1997 ᭧ 1997 Wiley-Liss, Inc. beling and was characterized as a monoadduct of