Mammary Biology and Tumorigenesis Laboratory, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA.
Exp Cell Res. 2010 Feb 1;316(3):422-32. doi: 10.1016/j.yexcr.2009.11.006. Epub 2009 Nov 12.
Amphiregulin (AREG), a ligand for epidermal growth factor receptor, is required for mammary gland ductal morphogenesis and mediates estrogen actions in vivo, emerging as an essential growth factor during mammary gland growth and differentiation. The COMMA-D beta-geo (CDbetageo) mouse mammary cell line displays characteristics of normal mammary progenitor cells including the ability to regenerate a mammary gland when transplanted into the cleared fat pad of a juvenile mouse, nuclear label retention, and the capacity to form anchorage-independent mammospheres. We demonstrate that AREG is essential for formation of floating mammospheres by CDbetageo cells and that the mitogen activated protein kinase signaling pathway is involved in AREG-mediated mammosphere formation. Addition of exogenous AREG promotes mammosphere formation in cells where AREG expression is knocked down by siRNA and mammosphere formation by AREG(-/-) mammary epithelial cells. AREG knockdown inhibits mammosphere formation by duct-limited mammary progenitor cells but not lobule-limited mammary progenitor cells. These data demonstrate AREG mediates the function of a subset of mammary progenitor cells in vitro.
双顺反子乳腺肿瘤病毒（CDβgeo）小鼠乳腺细胞系表现出正常乳腺祖细胞的特征，包括在幼年小鼠去脂垫中移植后能再生乳腺、核标签保留和形成无锚定独立乳腺球体的能力。我们证明表皮生长因子受体配体 Amphiregulin（AREG）对 CDβgeo 细胞形成漂浮乳腺球体是必需的，并且丝裂原活化蛋白激酶信号通路参与 AREG 介导的乳腺球体形成。外源性 AREG 的添加促进了由 siRNA 敲低 AREG 表达的细胞中乳腺球体的形成，以及 AREG(-/-)乳腺上皮细胞中乳腺球体的形成。AREG 敲低抑制了管腔限制的乳腺祖细胞而不是小叶限制的乳腺祖细胞的乳腺球体形成。这些数据表明 AREG 在体外介导了乳腺祖细胞的一个亚群的功能。
