Dipyridamole intervention of breast cell carcinogenesis.
Dietary prevention is a cost-efficient strategy to reduce the risk of human cancers. More than 85% breast cancers are sporadic and attributable to long-term exposure to environmental carcinogens through a multistep and multiyear disease process. We used our chronically induced cellular carcinogenesis model as a target to search for preventive agents capable of blocking breast cell carcinogenesis. Dipyridamole (DPM), at a non-cytotoxic physiologically achievable dose of 10  nmol/L, effectively blocked breast cell carcinogenesis induced by cumulative exposures to three unrelated carcinogens 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP), benzo[a]pyrene (B[a]P), and 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK). The ability of DPM to block H-Ras upregulation, thus blocking ERK pathway activation, reactive oxygen species (ROS) elevation, and DNA damage in each exposure, may account for its mechanisms in intervention of carcinogenesis induced by cumulative exposures to PhIP. Likewise, DPM's ability to block ROS elevation and DNA damage may account for its mechanisms in intervention of carcinogenesis chronically induced by NNK and B[a]P, as well. DPM is approved by the Food and Drug Administration to control platelet aggregation and vasoconstriction in patients. Our study revealed, for the first time, the novel ability of DPM to block breast cell carcinogenesis induced by three unrelated carcinogens. DPM should be seriously considered as a chemopreventive agent in development of strategies for reducing the risk of sporadic breast cancer associated with long-term exposure to environmental carcinogens.
Anticancer Molecular Oncology Laboratory, Department of Biomedical and Diagnostic Sciences, College of Veterinary Medicine, The University of Tennessee, Knoxville, Tennessee.
Shambhunath
S
Choudhary
Shilpa
S
Sood
Hwa-Chain Robert
HC
Wang
D017209:Apoptosis / Q000187:drug effects; D001564:Benzo(a)pyrene / Q000009:adverse effects; D015153:Blotting, Western; D001940:Breast / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology; D001943:Breast Neoplasms / Q000139:chemically induced / Q000188:drug therapy* / Q000378:metabolism / Q000473:pathology; D002273:Carcinogens / Q000494:pharmacology*; D002448:Cell Adhesion / Q000187:drug effects; D002465:Cell Movement / Q000187:drug effects; D049109:Cell Proliferation / Q000187:drug effects; D002471:Cell Transformation, Neoplastic / Q000187:drug effects*; D002478:Cells, Cultured; D004249:DNA Damage / Q000187:drug effects; D004176:Dipyridamole / Q000494:pharmacology*; D005260:Female; D006801:Humans; D007093:Imidazoles / Q000009:adverse effects; D020935:MAP Kinase Signaling System / Q000187:drug effects; D009602:Nitrosamines / Q000009:adverse effects; D017382:Reactive Oxygen Species / Q000378:metabolism; D014665:Vasodilator Agents / Q000494:pharmacology*
D002273:Carcinogens; D007093:Imidazoles; D009602:Nitrosamines; D017382:Reactive Oxygen Species; D014665:Vasodilator Agents; D001564:Benzo(a)pyrene; D004176:Dipyridamole; C016583:4-(N-methyl-N-nitrosamino)-1-(3-pyridyl)-1-butanone; C049584:2-amino-1-methyl-6-phenylimidazo(4,5-b)pyridine