Expression profiling of the estrogen responsive genes in response to phytoestrogens using a customized DNA microarray

Here, we examined phytoestrogens, isoflavones (genistein, daidzein, glycitein, biochanin A and ipriflavone), flavones (chrysin, luteolin and apigenin), flavonols (kaempferol and quercetin), and a coumestan, a flavanone and a chalcone (coumestrol, naringenin and phloretin, respectively) by means of a DNA microarray assay. A total of 172 estrogen responsive genes were monitored with a customized DNA microarray and their expression profiles for the above phytoestrogens were compared with that for 17β-estradiol (E2) using correlation coefficients, or R values, after a correlation analysis by linear regression. While R values indicate the similarity of the response by the genes, we also examined the genes by cluster analysis and by their specificity to phytoestrogens (specific to genistein, daidzein or glycitein) or gene functions. Several genes were selected from p53-related genes (CDKN1A, TP53I11 and CDC14), Akt2-related genes (PRKCD, BRCA1, TRIB3 and APPL), mitogen-activated protein kinase-related genes (RSK and SH3BP5), Ras superfamily genes (RAP1GA1, RHOC and ARHGDIA) and AP-1 family and related genes (RIP140, FOS, ATF3, JUN and FRA2). We further examined the extracts from two local crops of soy beans (Kuro-daizu or Mochi-daizu) by comparing the gene expression profiles with those of E2 or phytoestrogens as a first step in utilizing the expression profiles for various applications.