Metalloestrogenic effects of quantum dots.
OBJECTIVE
To investigate the metalloestrogenic effects of cadmium telluride quantum dots (QDs) in both human breast cancer cells and in vivo in mice.


METHODS
Human breast cancer cells (MCF-7 cells) were utilized to study QDs, cadmium and 17β-estradiol induced estrogen-related genomic and nongenomic signaling. Female prepubescent and ovariectomized adult mice were treated with CdTe QDs to assess whether QD-induced estrogenicity would lead to uterine changes.


CONCLUSIONS
Our findings demonstrate that in vitro cadmium-containing QDs induce cellular proliferation, estrogen receptor α activation, and biphasic phosphorylation of AKT and ERK1/2, comparable with 17β-estradiol. Green QDs elicited a more robust estrogenic response than orange QDs. Addition of the selective estrogen receptor antagonist, ICI 182780, completely abolished all QD-induced estrogenic effects, suggesting that QD-induced estrogenic signaling is mediated via the estrogen receptor. In vivo, chronic treatment of mice with QDs led to a two- to three-fold increase in uterine weight, comparable or greater than 17β-estradiol.


CONCLUSIONS
These findings suggest that certain cadmium-containing nanocrystals are endocrine disruptors, whose effects can exceed those induced by ionic cadmium or 17β-estradiol.
Department of Pharmacology & Therapeutics, McGill University, 3655 Promenade Sir-William-Osler, McIntyre Medical Sciences Building, Room 1314, Montreal, QC, H3G 1Y6, Canada.
Manasi P
MP
Jain
Farida
F
Vaisheva
Dusica
D
Maysinger
D000818:Animals; D019187:Cadmium Compounds / Q000008:administration & dosage*; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D004958:Estradiol / Q000031:analogs & derivatives / Q000494:pharmacology; D005260:Female; D000077267:Fulvestrant; D006801:Humans; D020935:MAP Kinase Signaling System / Q000187:drug effects; D051379:Mice; D051058:Oncogene Protein v-akt / Q000187:drug effects / Q000378:metabolism; D010766:Phosphorylation / Q000187:drug effects; D045663:Quantum Dots; D011960:Receptors, Estrogen / Q000037:antagonists & inhibitors* / Q000187:drug effects / Q000378:metabolism*; D013691:Tellurium / Q000008:administration & dosage*; D014599:Uterus / Q000187:drug effects
D019187:Cadmium Compounds; D011960:Receptors, Estrogen; D000077267:Fulvestrant; D004958:Estradiol; D051058:Oncogene Protein v-akt; D013691:Tellurium; C028337:cadmium telluride