Hierarchical clustering of primary estrogen receptor-positive breast cancers based on genome-wide microarray profiling

Copyright information:Taken from "Aging impacts transcriptomes but not genomes of hormone-dependent breast cancers"http://breast-cancer-research.com/content/9/5/R59Breast cancer research : BCR 2007;9(5):R59-R59.Published online 12 Sep 2007PMCID:PMC2216076. Unsupervised hierarchical clustering of 101 primary estrogen receptor (ER)-positive breast cancers, diagnosed in younger women (age ≤ 45 years) or older women (age ≥ 70 years), based on genome-wide microarray profiling of 6,632 variably expressed probes (~5.1 K unique genes). The cluster dendrogram defines six different transcriptome subtypes of ER-positive breast cancers (Group 1A, 1B, 2A, 2B, 3A, 3B), with significant age biases (< 0.05) but not biased by progesterone receptor (PR) status or ERBB2 status; horizontal colored bars identify the age cohort, PR status and ERBB2 status of the ER-positive samples in each column. The vertical red–green color scale shows logratios from mean centered gene expression levels. Magnified views show ESR1-containing (ER-associated) probe sets within the entire cluster diagram.