Apoptosis and catastrophic cell death in benzo[a]pyrene-transformed human breast epithelial cells.
Apoptosis and mitotic death, bi- and multinucleation, giant cells and micronucleation were investigated in human breast epithelial cell lines transformed by benzo[a]pyrene (BP) (BP1, BP1-E and BP1-E1 cells) and in BP1 cells transfected with the c-Ha-ras oncogene (BP1-Tras cells). Since BP induces apoptosis and the abnormal expression of ras genes elicits catastrophic mitosis, both cell death phenomena were expected to occur in this system, especially in BP1-Tras cells. Regardless of the cell line considered, single-nucleate cells were found to be eliminated preferentially through apoptosis, while bi- and multinucleate cells were eliminated through catastrophic mitosis. Apoptosis and catastrophic mitosis were observed in all cell lines but were significantly more frequent in BP1-Tras cells. The abnormal expression of Ha-ras in the latter cells may enhance in this system the effects of the BP apoptosis path reported for BP-transformed Hepa 1c1c7 hepatoma cells. Transfection with the ras oncogene also enhanced the mitotic disturbances, which produced multi- and micronucleation and mitotic death, possibly because of the genomic instability promoted by this oncogene in the BP-transformed cell line.
Barbisan
L F
LF
Department of Cell Biology, Institute of Biology, UNICAMP, Campinas, SP, Brazil.
Mello
M L
ML
Russo
J
J
Vidal
B C
BC
D017209:Apoptosis / Q000187:drug effects / Q000235:genetics; D001564:Benzo(a)pyrene / Q000633:toxicity*; D001940:Breast / Q000166:cytology* / Q000187:drug effects* / Q000473:pathology; D016923:Cell Death / Q000187:drug effects / Q000235:genetics; D002461:Cell Line, Transformed / Q000187:drug effects; D002467:Cell Nucleus / Q000187:drug effects; D002471:Cell Transformation, Neoplastic; D004847:Epithelial Cells / Q000166:cytology / Q000187:drug effects / Q000473:pathology; D011905:Genes, ras; D006801:Humans; D008938:Mitosis / Q000187:drug effects; D008940:Mitotic Index; D014162:Transfection
D001564:Benzo(a)pyrene