乳腺干细胞的识别、再生、分化及其调控

乳腺发育与再生取决于乳腺干细胞的再生。乳腺干细胞及其龛于乳腺导管发育时期分布在乳腺原基导管终端芽（TEB）帽区，在成体乳腺，以规则性的间距分布在整个乳腺导管系统，而主要位于终末导管（TD）。可利用表型标记、Sp分析及体外培养乳腺球形成以识别乳腺干细胞。乳腺干细胞后代的级别分化首先是双能祖细胞，而后，腔限制性与肌限制性细胞。妊娠可诱发具自我更新性与多能性的上皮细胞亚型PI．MEC。小鼠乳腺干细胞在青春期与妊娠期分别由雌激素与孕激素调控。乳腺干／祖细胞的自我更新与分化受wnt、Hedgehog、Notch与TGF．beta等信号转导系统相关的诸多因素调控。

Identification, regeneration, differentiation and regulation of breast stem cell

The development and regeneration of the breast depend upon the proliferation of the breast stem cell （BSC）. BSCs with their niches are in the cap areas of the terminal end buds （TEBs） in the primordial duct system of the breast rudimentum in embryos, and distributed with regular interval in the duct system, mainly in the terminal duct areas of the adult breast. The BSCs may be identified by using phenotypic markers, Sp analysis and mammosphere formation in vitro. The hierarchy-differentiation of the progeny of BSC is firstly bi- potential progenitors, then, lumen-restricted and myo-restricted cells. Pregnancy can induce PI-MEC with self- renewal and multipotential ability. The BSCs in puberty and pregnancy are controlled separately by estrogen and progesterone. The self-renewal and differentiation ability of the stem cells or the progenitors of the breast epithelium are controlled by some factors of several signal transduction systems, such as Wnt, Hedgehog, Notch and TGF-beta etc.