title: Estrogen receptor status in breast cancer is associated with remarkably distinct gene expression patterns.
abstract: To investigate the phenotype associated with estrogen receptor alpha (ER) expression in breast carcinoma, gene expression profiles of 58 node-negative breast carcinomas discordant for ER status were determined using DNA microarray technology. Using artificial neural networks as well as standard hierarchical clustering techniques, the tumors could be classified according to ER status, and a list of genes which discriminate tumors according to ER status was generated. The artificial neural networks could accurately predict ER status even when excluding top discriminator genes, including ER itself. By reference to the serial analysis of gene expression database, we found that only a small proportion of the 100 most important ER discriminator genes were also regulated by estradiol in MCF-7 cells. The results provide evidence that ER+ and ER- tumors display remarkably different gene-expression phenotypes not solely explained by differences in estrogen responsiveness.
authors.affiliation: Department of Oncology, Lund University, SE-221 00 Lund, Sweden.
authors.forename: S
authors.initials: S
authors.lastname: Gruvberger
authors.forename: M
authors.initials: M
authors.lastname: Ringnér
authors.forename: Y
authors.initials: Y
authors.lastname: Chen
authors.forename: S
authors.initials: S
authors.lastname: Panavally
authors.forename: L H
authors.initials: LH
authors.lastname: Saal
authors.lastname: Borg A
authors.forename: M
authors.initials: M
authors.lastname: Fernö
authors.forename: C
authors.initials: C
authors.lastname: Peterson
authors.forename: P S
authors.initials: PS
authors.lastname: Meltzer
mesh_terms: D001943:Breast Neoplasms / Q000235:genetics* / Q000378:metabolism* / Q000473:pathology; D002138:Calibration; D019070:Cell Lineage; D016000:Cluster Analysis; D004958:Estradiol / Q000494:pharmacology; D047628:Estrogen Receptor alpha; D005260:Female; D015870:Gene Expression / Q000187:drug effects; D020869:Gene Expression Profiling; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D008957:Models, Genetic; D016571:Neural Networks, Computer; D020411:Oligonucleotide Array Sequence Analysis; D010641:Phenotype; D011960:Receptors, Estrogen / Q000096:biosynthesis* / Q000235:genetics; D015203:Reproducibility of Results; D014407:Tumor Cells, Cultured
chemical_list: D047628:Estrogen Receptor alpha; D011960:Receptors, Estrogen; D004958:Estradiol