title: Stanniocalcin 2 is an estrogen-responsive gene coexpressed with the estrogen receptor in human breast cancer.
abstract: Differences in gene expression are likely to explain the phenotypic variation between hormone-responsive and hormone-unresponsive breast cancers. In this study, DNA microarray analysis of approximately 10,000 known genes and 25,000 expressed sequence tag clusters was performed to identify genes induced by estrogen and repressed by the pure antiestrogen ICI 182 780 in vitro that correlated with estrogen receptor (ER) expression in primary breast carcinomas in vivo. Stanniocalcin (STC) 2 was identified as one of the genes that fulfilled these criteria. DNA microarray hybridization showed a 3-fold induction of STC2 mRNA expression in MCF-7 cells in < or = 3 h of estrogen exposure and a 3-fold repression in the presence of antiestrogen (one-way ANOVA, P < 0.0005). In 13 ER-positive and 12 ER-negative breast carcinomas, the microarray-derived mRNA levels observed for STC2 correlated with tumor ER mRNA (Pearson's correlation, r = 0.85; P < 0.0001) and ER protein status (Spearman's rank correlation, r = 0.73; P < 0.0001). The expression profile of STC2 was further confirmed by in situ hybridization and immunohistochemistry on a larger cohort of 236 unselected breast carcinomas using tissue microarrays. STC2 mRNA and protein expression were found to be associated with tumor ER status (Fisher's exact test, P < 0.005). The related gene, STC1, was also examined and shown to be associated with ER status in breast carcinomas (Fisher's exact test, P < 0.05). This study demonstrates the feasibility of using global gene expression data derived from an in vitro model to pinpoint novel estrogen-responsive genes of potential clinical relevance.
authors.affiliation: Cancer Functional Genomics Unit, Murdoch Children's Research Institute, 10 Floor Royal Children's Hospital, Parkville, Victoria 3052, Australia. bourast@murdoch.rch.unimelb.edu.au
authors.forename: Toula
authors.initials: T
authors.lastname: Bouras
authors.forename: Melissa C
authors.initials: MC
authors.lastname: Southey
authors.forename: Andy C
authors.initials: AC
authors.lastname: Chang
authors.forename: Roger R
authors.initials: RR
authors.lastname: Reddel
authors.forename: Dorian
authors.initials: D
authors.lastname: Willhite
authors.forename: Richard
authors.initials: R
authors.lastname: Glynne
authors.forename: Michael A
authors.initials: MA
authors.lastname: Henderson
authors.forename: Jane E
authors.initials: JE
authors.lastname: Armes
authors.forename: Deon J
authors.initials: DJ
authors.lastname: Venter
mesh_terms: D001943:Breast Neoplasms / Q000737:chemistry / Q000235:genetics*; D004958:Estradiol / Q000031:analogs & derivatives* / Q000494:pharmacology; D004967:Estrogens / Q000494:pharmacology*; D005260:Female; D000077267:Fulvestrant; D006023:Glycoproteins / Q000032:analysis / Q000235:genetics*; D006801:Humans; D036341:Intercellular Signaling Peptides and Proteins; D020411:Oligonucleotide Array Sequence Analysis; D011506:Proteins / Q000032:analysis; D012333:RNA, Messenger / Q000032:analysis*; D011960:Receptors, Estrogen / Q000032:analysis / Q000235:genetics*; D000071163:Trefoil Factor-1; D014407:Tumor Cells, Cultured; D025521:Tumor Suppressor Proteins
chemical_list: D004967:Estrogens; D006023:Glycoproteins; D036341:Intercellular Signaling Peptides and Proteins; D011506:Proteins; D012333:RNA, Messenger; D011960:Receptors, Estrogen; C114997:STC2 protein, human; C051838:TFF1 protein, human; D000071163:Trefoil Factor-1; D025521:Tumor Suppressor Proteins; D000077267:Fulvestrant; D004958:Estradiol