title: Atbf1 regulates pubertal mammary gland development likely by inhibiting the pro-proliferative function of estrogen-ER signaling.
abstract: ATBF1 is a candidate tumor suppressor that interacts with estrogen receptor (ER) to inhibit the function of estrogen-ER signaling in gene regulation and cell proliferation control in human breast cancer cells. We therefore tested whether Atbf1 and its interaction with ER modulate the development of pubertal mammary gland, where estrogen is the predominant steroid hormone. In an in vitro model of cell differentiation, i.e., MCF10A cells cultured in Matrigel, ATBF1 expression was significantly increased, and knockdown of ATBF1 inhibited acinus formation. During mouse mammary gland development, Atbf1 was expressed at varying levels at different stages, with higher levels during puberty, lower during pregnancy, and the highest during lactation. Knockout of Atbf1 at the onset of puberty enhanced ductal elongation and bifurcation and promoted cell proliferation in both ducts and terminal end buds of pubertal mammary glands. Enhanced cell proliferation primarily occurred in ER-positive cells and was accompanied by increased expression of ER target genes. Furthermore, inactivation of Atbf1 reduced the expression of basal cell markers (CK5, CK14 and CD44) but not luminal cell markers. These findings indicate that Atbf1 plays a role in the development of pubertal mammary gland likely by modulating the function of estrogen-ER signaling in luminal cells and by modulating gene expression in basal cells.
authors.affiliation: Department of Genetics and Cell Biology, College of Life Sciences, Nankai University, Tianjin, China.
authors.forename: Mei
authors.initials: M
authors.lastname: Li
authors.forename: Xiaoying
authors.initials: X
authors.lastname: Fu
authors.forename: Gui
authors.initials: G
authors.lastname: Ma
authors.forename: Xiaodong
authors.initials: X
authors.lastname: Sun
authors.forename: Xueyuan
authors.initials: X
authors.lastname: Dong
authors.forename: Tamas
authors.initials: T
authors.lastname: Nagy
authors.forename: Changsheng
authors.initials: C
authors.lastname: Xing
authors.forename: Jie
authors.initials: J
authors.lastname: Li
authors.forename: Jin-Tang
authors.initials: JT
authors.lastname: Dong
mesh_terms: D000818:Animals; D001483:Base Sequence; D001940:Breast / Q000254:growth & development*; D045744:Cell Line, Tumor; D017931:DNA Primers; D005260:Female; D018398:Homeodomain Proteins / Q000235:genetics / Q000502:physiology*; D006801:Humans; D007150:Immunohistochemistry; D051379:Mice; D011627:Puberty; D060888:Real-Time Polymerase Chain Reaction; D011960:Receptors, Estrogen / Q000378:metabolism*; D015398:Signal Transduction
chemical_list: D017931:DNA Primers; D018398:Homeodomain Proteins; D011960:Receptors, Estrogen; C489511:Zfhx3 protein, mouse; C071660:ZFHX3 protein, human