Gene expression signature of atypical breast hyperplasia and regulation by SFRP1.

TitleGene expression signature of atypical breast hyperplasia and regulation by SFRP1.
Publication TypeJournal Article
Year of Publication2019
AuthorsGregory, KJ, Roberts, AL, Conlon, EM, Mayfield, JA, Hagen, MJ, Crisi, GM, Bentley, BA, Kane, JJ, Makari-Judson, G, Mason, HS, Yu, J, Zhu, LJulie, Simin, K, Johnson, JPS, Khan, A, Schneider, BR, Schneider, SS, D Jerry, J
JournalBreast Cancer Res
Date Published2019 06 27
KeywordsAdult, Animals, Biomarkers, Biomarkers, Tumor, Breast Neoplasms, Disease Models, Animal, Disease Progression, Female, Gene Expression Profiling, Gene Expression Regulation, Gene Regulatory Networks, Humans, Hyperplasia, Intercellular Signaling Peptides and Proteins, Mammary Glands, Human, Membrane Proteins, Mice, Mice, Knockout, Middle Aged, Signal Transduction, Transcriptome

BACKGROUND: Atypical breast hyperplasias (AH) have a 10-year risk of progression to invasive cancer estimated at 4-7%, with the overall risk of developing breast cancer increased by ~ 4-fold. AH lesions are estrogen receptor alpha positive (ERα+) and represent risk indicators and/or precursor lesions to low grade ERα+ tumors. Therefore, molecular profiles of AH lesions offer insights into the earliest changes in the breast epithelium, rendering it susceptible to oncogenic transformation.

METHODS: In this study, women were selected who were diagnosed with ductal or lobular AH, but no breast cancer prior to or within the 2-year follow-up. Paired AH and histologically normal benign (HNB) tissues from patients were microdissected. RNA was isolated, amplified linearly, labeled, and hybridized to whole transcriptome microarrays to determine gene expression profiles. Genes that were differentially expressed between AH and HNB were identified using a paired analysis. Gene expression signatures distinguishing AH and HNB were defined using AGNES and PAM methods. Regulation of gene networks was investigated using breast epithelial cell lines, explant cultures of normal breast tissue and mouse tissues.

RESULTS: A 99-gene signature discriminated the histologically normal and AH tissues in 81% of the cases. Network analysis identified coordinated alterations in signaling through ERα, epidermal growth factor receptors, and androgen receptor which were associated with the development of both lobular and ductal AH. Decreased expression of SFRP1 was also consistently lower in AH. Knockdown of SFRP1 in 76N-Tert cells resulted altered expression of 13 genes similarly to that observed in AH. An SFRP1-regulated network was also observed in tissues from mice lacking Sfrp1. Re-expression of SFRP1 in MCF7 cells provided further support for the SFRP1-regulated network. Treatment of breast explant cultures with rSFRP1 dampened estrogen-induced progesterone receptor levels.

CONCLUSIONS: The alterations in gene expression were observed in both ductal and lobular AH suggesting shared underlying mechanisms predisposing to AH. Loss of SFRP1 expression is a significant regulator of AH transcriptional profiles driving previously unidentified changes affecting responses to estrogen and possibly other pathways. The gene signature and pathways provide insights into alterations contributing to AH breast lesions.

Alternate JournalBreast Cancer Res
PubMed ID31248446
PubMed Central IDPMC6598287
Grant ListR01 ES015739 / ES / NIEHS NIH HHS / United States
U01 ES026140 / ES / NIEHS NIH HHS / United States