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

• Published in: Journal of applied toxicology Vol. 27; no. 1; pp. 67 - 77
• Main Authors: Pugazhendhi, D, Sadler, A J, Darbre, P D
• Format: Journal Article
• Language: English
• Published: 01-01-2007
• ISSN: 0260-437X
• 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 17[beta]-oestradiol, the question remains as to the full extent of the similarity in the overall gene profile induced in response to parabens compared with 17[beta]-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 X 10 super(-4) m methylparaben, 10 super(-5) m n-butylparaben and 10 super(-8) m 17[beta]- oestradiol. At these concentrations, the parabens gave growth responses in MCF7 cells of similar magnitude to 17[beta]-oestradiol. The study identified genes which are upregulated or downregulated to a similar extent by methylparaben, n-butylparaben and 17[beta]-oestradiol. However, the majority of genes were not regulated in the same way by all three treatments. Some genes responded differently to parabens from 17[beta]-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 17[beta]-oestradiol.