title: Filtered, tar-free and aerosol-free cigarette-smoke causes accumulation of the tumor-suppressor protein p53 in rodent cells.
abstract: Cigarette smoke was filtered with a Cambridge glass fiber filter retaining 99.9% of the tar and aerosol fraction and diluted 1:5 with air. The murine cell line L929 was exposed to this smoke preparation for periods of up to 10 min. Thereafter the following parameters were determined at different times: Nuclear accumulation of the tumor suppressor protein p53 indicating chromatin injury (by immunostaining); apoptotic DNA fragmentation (by DNA end labelling with biotin-16-dUTP in the presence of terminal deoxyribonucleotidyl transferase); the intracellular level of reactive oxygen intermediates (ROI) (by cytofluorimetry with the fluorigenic stain 2',7'-dichlorofluorescin diacetate). After 1 min exposure to 1:5 air-diluted filtered cigarette smoke maximal p53 accumulation occured about 20 h later, whereas maximal DNA fragmentation and apoptosis and maximal ROI levels were found after 10 min of exposure. Obviously, even the diluted, tar- and aerosol-free fraction of cigarette smoke has the potency, after 1 min of exposure only, to exert severe DNA damage, a potential transformation risk for the surviving cell fraction, in murine cell cultures as indicated by stabilization and accumulation of the tumor suppressor protein p53.
authors.affiliation: UNIV FREIBURG, INST MED MIKROBIOL & HYG, VIROL ABT, W-7900 FREIBURG, GERMANY.
authors.forename: A
authors.initials: A
authors.lastname: Schulzelutum
authors.forename: J
authors.initials: J
authors.lastname: Siegel
authors.forename: R
authors.initials: R
authors.lastname: Schmidt
authors.forename: B
authors.initials: B
authors.lastname: Plaumann
authors.forename: C
authors.initials: C
authors.lastname: Braun
authors.forename: C
authors.initials: C
authors.lastname: Haessler
authors.forename: G
authors.initials: G
authors.lastname: Brandner
authors.forename: R
authors.initials: R
authors.lastname: Hess