Université Libre de Bruxelles, IRIBHM, Brussels B-1070, Belgium.
Nature. 2011 Oct 9;479(7372):189-93. doi: 10.1038/nature10573.
The mammary epithelium is composed of several cell lineages including luminal, alveolar and myoepithelial cells. Transplantation studies have suggested that the mammary epithelium is maintained by the presence of multipotent mammary stem cells. To define the cellular hierarchy of the mammary gland during physiological conditions, we performed genetic lineage-tracing experiments and clonal analysis of the mouse mammary gland during development, adulthood and pregnancy. We found that in postnatal unperturbed mammary gland, both luminal and myoepithelial lineages contain long-lived unipotent stem cells that display extensive renewing capacities, as demonstrated by their ability to clonally expand during morphogenesis and adult life as well as undergo massive expansion during several cycles of pregnancy. The demonstration that the mammary gland contains different types of long-lived stem cells has profound implications for our understanding of mammary gland physiology and will be instrumental in unravelling the cells at the origin of breast cancers.
乳腺上皮由多个细胞谱系组成，包括腔细胞、肺泡细胞和肌上皮细胞。移植研究表明，乳腺上皮由多能乳腺干细胞的存在维持。为了在生理条件下定义乳腺的细胞层次结构，我们在发育、成年和怀孕期间对小鼠乳腺进行了遗传谱系追踪实验和克隆分析。我们发现，在出生后未受干扰的乳腺中，腔细胞和肌上皮谱系都包含寿命长的单能干细胞，这些干细胞具有广泛的更新能力，这表现在它们在形态发生和成年期以及在多次怀孕周期中能够克隆性扩张的能力上。证明乳腺中含有不同类型的长寿干细胞，这对我们理解乳腺生理学具有深远的意义，并将有助于揭示乳腺癌起源细胞。
