Transcriptional program activated by R1881 exposure in LNCaP cells. (a) Hierarchical cluster analysis of androgen-responsive genes in LNCaP cells treated with R1881. This is a scaled-down overview of the cluster diagram generated by querying microarray data against the list of genes generated by SAM analysis (see text). The complete image with all gene names is viewable at . Each column represents data from microarray analysis of a single RNA sample from LNCaP cells corresponding to a given time; the columns under the green heading show data in which RNA from R1881-treated and control cells were hybridized on the same microarray, while those under the black heading show experiments in which RNA from treated cells was hybridized against a common reference and normalized to the '0' time point. Numbers above each column denote specific time points. The dose of R1881 was 1 nM in all experiments. Red squares indicate transcripts with expression levels higher than that of ethanol-treated control cells; green squares, levels lower than that of controls; black, levels approximately equal to those in controls; gray, data of insufficient quality. (b) Representative androgen-regulated genes measured in microarray analysis of LNCaP cells treated with 1 nM R1881. Expression profiles of transcripts representing previously published androgen target genes are depicted. Genes listed more than once indicate that the microarray contained multiple elements representing that gene. As indicated by the scale bar, color saturation reflects magnitude of expression ratio.