TY - JOUR
T1 - Loss of Limb-Bud-and-Heart (LBH) attenuates mammary hyperplasia and tumor development in MMTV-Wnt1 transgenic mice
AU - Ashad-Bishop, Kilan
AU - Garikapati, Koteswararao
AU - Lindley, Linsey E.
AU - Jorda, Merce
AU - Briegel, Karoline J.
N1 - Funding Information:
This work was supported by the National Institute of General Medical Science of the National Institutes of Health (Award Number R01GM113256 ). We thank Dr. Xin-Hai Pei for comments on the manuscript.
PY - 2019/1/8
Y1 - 2019/1/8
N2 - WNT/β-catenin signaling plays pivotal roles in mammary development and tumorigenesis; and aberrant activation of this pathway is frequently observed in human breast cancer, correlating with poor outcome. However, the mechanisms underlying WNT-driven mammary tumorigenesis remain incompletely understood. Here, we used mouse mammary tumor virus (MMTV)-Wnt1 transgenic mice, which develop aggressive mammary adenocarcinomas, to examine whether Limb-Bud-and-Heart (LBH) - a WNT/β-catenin target transcription co-factor overexpressed in human triple-negative breast cancers with WNT pathway hyperactivation, contributes to WNT-induced tumorigenesis. We found LBH is specifically overexpressed in basal epithelial tumor cells of MMTV-Wnt1 mammary tumors reminiscent of its basal cell-restricted expression in the normal postnatal mammary gland. To determine the role of LBH in mammary tumorigenesis, we crossed MMTV-Wnt1 mice with basal epithelial-specific Keratin 14/K14-Cre;LbhloxP knockout mice. Mammary glands from virgin LBH-deficient MMTV-Wnt1 mice exhibited reduced hyperplasia, cell proliferation and increased apoptosis. Importantly, LBH inactivation in mammary epithelium significantly delayed tumor onset in MMTV-Wnt1 transgenic mice, with a median tumor-free survival of 32.5 weeks compared to 22.5 weeks in control LBH wild type MMTV-Wnt1 mice (p < 0.05). This data provides the first evidence that LBH plays an essential role in WNT-induced mammary tumorigenesis by promoting hyperplastic growth and tumor formation.
AB - WNT/β-catenin signaling plays pivotal roles in mammary development and tumorigenesis; and aberrant activation of this pathway is frequently observed in human breast cancer, correlating with poor outcome. However, the mechanisms underlying WNT-driven mammary tumorigenesis remain incompletely understood. Here, we used mouse mammary tumor virus (MMTV)-Wnt1 transgenic mice, which develop aggressive mammary adenocarcinomas, to examine whether Limb-Bud-and-Heart (LBH) - a WNT/β-catenin target transcription co-factor overexpressed in human triple-negative breast cancers with WNT pathway hyperactivation, contributes to WNT-induced tumorigenesis. We found LBH is specifically overexpressed in basal epithelial tumor cells of MMTV-Wnt1 mammary tumors reminiscent of its basal cell-restricted expression in the normal postnatal mammary gland. To determine the role of LBH in mammary tumorigenesis, we crossed MMTV-Wnt1 mice with basal epithelial-specific Keratin 14/K14-Cre;LbhloxP knockout mice. Mammary glands from virgin LBH-deficient MMTV-Wnt1 mice exhibited reduced hyperplasia, cell proliferation and increased apoptosis. Importantly, LBH inactivation in mammary epithelium significantly delayed tumor onset in MMTV-Wnt1 transgenic mice, with a median tumor-free survival of 32.5 weeks compared to 22.5 weeks in control LBH wild type MMTV-Wnt1 mice (p < 0.05). This data provides the first evidence that LBH plays an essential role in WNT-induced mammary tumorigenesis by promoting hyperplastic growth and tumor formation.
KW - Breast cancer
KW - Limb-Bud-and-Heart
KW - Mammary tumorigenesis
KW - Mouse model
KW - WNT/β-catenin signaling
UR - http://www.scopus.com/inward/record.url?scp=85057492621&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85057492621&partnerID=8YFLogxK
U2 - 10.1016/j.bbrc.2018.11.155
DO - 10.1016/j.bbrc.2018.11.155
M3 - Article
C2 - 30509497
AN - SCOPUS:85057492621
VL - 508
SP - 536
EP - 542
JO - Biochemical and Biophysical Research Communications
JF - Biochemical and Biophysical Research Communications
SN - 0006-291X
IS - 2
ER -