Comparison of the global gene expression profiles produced by methylparaben, n-butylparaben and 17β-oestradiol in MCF7 human breast cancer cells

• Published in: Journal of applied toxicology 2007-01, Vol.27 (1), p.67-77
• Main Authors: Pugazhendhi, D., Sadler, A. J., Darbre, P. D.
• Format: Article
• Language: English
• Subjects: Biological and medical sciences; breast cancer cells; environmental oestrogen; global gene expression profiles; Gynecology. Andrology. Obstetrics; Mammary gland diseases; MCF7 cells; Medical sciences; microarray; parabens; Toxicology; Tumors
• ISSN: 0260-437X; 1099-1263
• DOI: 10.1002/jat.1200

Since the alkyl esters of p‐hydroxybenzoic acid (parabens) can be measured intact in the human breast and possess oestrogenic properties, it has been suggested that they could contribute to an aberrant burden of oestrogen signalling in the human breast and so play a role in the rising incidence of breast cancer. However, although parabens have been shown to regulate a few single genes (reporter genes, pS2, progesterone receptor) in a manner similar to that of 17β‐oestradiol, the question remains as to the full extent of the similarity in the overall gene profile induced in response to parabens compared with 17β‐oestradiol. The GE‐Amersham CodeLink 20 K human expression microarray system was used to profile the expression of 19881 genes in MCF7 human breast cancer cells following a 7‐day exposure to 5 × 10−4 m methylparaben, 10−5 m n‐butylparaben and 10−8 m 17β‐oestradiol. At these concentrations, the parabens gave growth responses in MCF7 cells of similar magnitude to 17β‐oestradiol. The study identified genes which are upregulated or downregulated to a similar extent by methylparaben, n‐butylparaben and 17β‐oestradiol. However, the majority of genes were not regulated in the same way by all three treatments. Some genes responded differently to parabens from 17β‐oestradiol, and furthermore, differences in expression of some genes could be detected even between the two individual parabens. Therefore, although parabens possess oestrogenic properties, their mimicry in terms of global gene expression patterns is not perfect and differences in gene expression profiles could result in consequences to the cells that are not identical to those following exposure to 17β‐oestradiol. Copyright © 2006 John Wiley & Sons, Ltd.