Lower concentrations of phthalates induce proliferation in human breast cancer cells

• Published in: Climacteric : the journal of the International Menopause Society Vol. 17; no. 4; pp. 377 - 384
• Main Authors: Chen, F.-P., Chien, M.-H.
• Format: Journal Article
• Language: English
• Published: England Informa Healthcare 01-08-2014; Taylor & Francis; Taylor & Francis Ltd
• Subjects: Apoptosis - drug effects; Bioassays; Breast cancer; BUTYL BENZYL PHTHALATE; Cell Proliferation - drug effects; Cells; DI-2-ETHYLHEXYL PHTHALATE; DI-n-BUTYL PHTHALATE; Dibutyl Phthalate - pharmacology; Diethylhexyl Phthalate - pharmacology; Dose-Response Relationship, Drug; Estrogens - pharmacology; Female; Humans; MCF-7 BREAST CANCER CELLS; MCF-7 Cells; Phosphatidylinositol 3-Kinases - analysis; Phosphatidylinositol 3-Kinases - metabolism; Phthalic Acids - pharmacology; PI3K/AKT SIGNALING PATHWAY; Plasticizers - pharmacology; Proliferating Cell Nuclear Antigen - analysis; Proliferating Cell Nuclear Antigen - metabolism; Proteins; Proto-Oncogene Proteins c-akt - analysis; Proto-Oncogene Proteins c-akt - metabolism; Signal Transduction - drug effects; Teratogens - pharmacology; Womens health; DI-n-BUTYL PHTHALATE; PI3K/AKT SIGNALING PATHWAY; MCF-7 BREAST CANCER CELLS; BUTYL BENZYL PHTHALATE; DI-2-ETHYLHEXYL PHTHALATE
• ISSN: 1369-7137; 1473-0804
• DOI: 10.3109/13697137.2013.865720

Abstract
Objective To explore the effect and pathway of phthalates on the growth of MCF-7 breast cancer cells.
Methods MCF-7 cells were treated with benzyl butyl phthalate (BBP), di-n-butyl phthalate (DBP), and di-2-ethylhexyl phthalate (DEHP) (10−10-10−4 mol/l). After incubation for 24, 48, 72, and 92 h, the cells were harvested and extracted for 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. The proteins involving proliferative and apoptotic pathways were evaluated by Western blot analysis.
Results MTT assay revealed cell toxicity at more than 10−5 mol/l for DEHP and at 10−4 mol/l for both BBP and DBP in MCF-7 cells. Cell proliferation was significantly increased at 10−8-10−5 mol/l of BBP and DBP, and at 10−8-10−6 mol/l of DEHP treatment. Proliferating cell nuclear antigen (PCNA) was substantially increased in cultures with DEHP (10−8-10−6 mol/l), BBP (10−8-10−5 mol/l), and DBP (10−7-10−5 mol/l). Obvious increases in PI3K, p-AKT, and PCNA were noted in cultures with 17β-estradiol, BBP, DBP, and DEHP. Estrogen receptor α expression was also notably increased in treatment with estradiol, BBP, DBP, and DEHP.
Conclusions The present study demonstrates that, even at a very low concentration, BBP, DBP, and DEHP were not only still capable of inducing a proliferative effect through the PI3K/AKT signaling pathway but also displaying estrogenic activity. Therefore, the current reference doses for phthalates defined by governments should be further evaluated.