Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
24
pubmed:dateCreated
2007-12-19
pubmed:abstractText
The use of agents to prevent the onset of and/or the progression to breast cancer has the potential to lower breast cancer risk. We have previously shown that the tumor-suppressor gene p53 is a potential mediator of hormone (estrogen/progesterone)-induced protection against chemical carcinogen-induced mammary carcinogenesis in animal models. Here, we show for the first time a breast cancer-protective effect of chloroquine in an animal model. Chloroquine significantly reduced the incidence of N-methyl-N-nitrosourea-induced mammary tumors in our animal model similar to estrogen/progesterone treatment. No protection was seen in our BALB/c p53-null mammary epithelium model, indicating a p53 dependency for the chloroquine effect. Using a human nontumorigenic mammary gland epithelial cell line, MCF10A, we confirm that in the absence of detectable DNA damage, chloroquine activates the tumor-suppressor p53 and the p53 downstream target gene p21, resulting in G(1) cell cycle arrest. p53 activation occurs at a posttranslational level via chloroquine-dependent phosphorylation of the checkpoint protein kinase, ataxia telangiectasia-mutated (ATM), leading to ATM-dependent phosphorylation of p53. In primary mammary gland epithelial cells isolated from p53-null mice, chloroquine does not induce G(1) cell cycle arrest compared with cells isolated from wild-type mice, also indicating a p53 dependency. Our results indicate that a short prior exposure to chloroquine may have a preventative application for mammary carcinogenesis.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Dec
pubmed:issn
1538-7445
pubmed:author
pubmed:issnType
Electronic
pubmed:day
15
pubmed:volume
67
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
12026-33
pubmed:dateRevised
2011-11-2
pubmed:meshHeading
pubmed:year
2007
pubmed:articleTitle
Ataxia telangiectasia-mutated and p53 are potential mediators of chloroquine-induced resistance to mammary carcinogenesis.
pubmed:affiliation
Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, Texas 77030, USA.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't, Research Support, N.I.H., Extramural