Abstract 3273: Prolactin promotes breast lesion progression and alters tumor histotype

• Published in: Cancer research (Chicago, Ill.) Ill.), 2010-04, Vol.70 (8_Supplement), p.3273-3273
• Main Authors: O'Leary, Kathleen A., Moser, Amy R., Schuler, Linda A.
• Format: Article
• Language: English
• ISSN: 0008-5472; 1538-7445
• DOI: 10.1158/1538-7445.AM10-3273

Prolactin (PRL) is critical for mammary development and lactation. Epidemiological studies also support a role for PRL in breast cancer (1). In order to study the contributions of PRL to tumor development and progression, we developed a transgenic mouse model that expresses PRL in the mammary epithelial cells (NRL-PRL), mimicking the mammary PRL production in women (2). To explore the interactions of PRL and Wnts in mammary tumorigenesis, NRL-PRL mice were crossed with APCmin/+ mice, which have elevated canonical Wnt signals secondary to reduced β-catenin degradation. Females were administered a single ip dose of ENU (50 mg/kg body weight) at 35-40 days of age. This paradigm in the F1 (FVB/N x C57BL/6J) strain background resulted in few mammary tumors (14%) in NRL-PRL nonparous females. APCmin/+ animals developed tumors at a slightly higher incidence (27%), as previously reported (3). However, penetrance rose to 66% in NRL-PRL/APCmin/+ females, indicating that PRL potentiates APCmin/+-induced tumorigenesis (P=0.008). The presence of PRL also strongly impacted the tumor histotype (P