Cunha G R
Department of Anatomy and Reproductive Endocrinology Center, University of California, San Francisco.
Cancer. 1994 Aug 1;74(3 Suppl):1030-44. doi: 10.1002/1097-0142(19940801)74:3+<1030::aid-cncr2820741510>3.0.co;2-q.
Development of the mammary gland (MG) and prostate occurs via mesenchymal-epithelia interactions. Epithelial MG buds are induced in ventral epidermis by mammary mesenchyme, which ultimately specifies the functional expression of the ability to produce milk. Mammary ductal branching is induced by embryonic mammary mesenchyme and is promoted by the mammary fat pad postnatally. These influences of connective tissue on the differentiation of mammary epithelium (ME) begin prenatally, but in adulthood, the connective tissue environment of adult ME profoundly influences epithelial growth, ductal branching, epithelial differentiation, and the ability of adult ME to produce milk. In a similar fashion, prostatic development occurs via mesenchymal-epithelial interactions in which urogenital sinus mesenchyme (UGM) induces epithelial morphogenesis, regulates epithelial proliferation, and evokes the expression of epithelial androgen receptors and prostate-specific secretory proteins. Although prostatic development is induced by androgens, androgenic effects on epithelial development are elicited via androgen receptors of UGM. As in MG, mesenchymal-epithelial interactions in the prostate begin during fetal periods, but continue into adulthood. The responsiveness of adult epithelial cells from various glands to stroma raises the possibility that carcinomas also may be regulated by connective tissue. Indeed, UGM can induce a rat prostatic carcinoma (Dunning tumor) to undergo striking changes in differentiation, which are accompanied by a reduction in growth rate and an apparent loss of tumorigenesis. Although the mechanism of mesenchymal-epithelial interactions remains unknown, the communication between the epithelium and stroma undoubtedly is multifactorial, involving the extracellular matrix, soluble growth or differentiation, and angiogenesis.
乳腺（MG）和前列腺的发育是通过间充质-上皮相互作用实现的。乳腺间充质在腹侧表皮诱导上皮性乳腺芽的形成，最终决定产生乳汁能力的功能性表达。胚胎期乳腺间充质诱导乳腺导管分支，出生后乳腺脂肪垫促进其生长。结缔组织对乳腺上皮（ME）分化的这些影响在出生前就开始了，但在成年期，成年ME的结缔组织环境深刻影响上皮生长、导管分支、上皮分化以及成年ME产生乳汁的能力。同样，前列腺的发育也是通过间充质-上皮相互作用进行的，其中泌尿生殖窦间充质（UGM）诱导上皮形态发生、调节上皮增殖，并引发上皮雄激素受体和前列腺特异性分泌蛋白的表达。虽然前列腺的发育是由雄激素诱导的，但雄激素对上皮发育的作用是通过UGM的雄激素受体介导的。与乳腺一样，前列腺中的间充质-上皮相互作用在胎儿期开始，但持续到成年期。来自各种腺体的成年上皮细胞对基质的反应性增加了癌症也可能受结缔组织调节的可能性。事实上，UGM可以诱导大鼠前列腺癌（邓宁肿瘤）在分化上发生显著变化，同时伴随着生长速率的降低和肿瘤发生能力的明显丧失。虽然间充质-上皮相互作用的机制尚不清楚，但上皮和基质之间的通讯无疑是多因素的，涉及细胞外基质、可溶性生长或分化因子以及血管生成。
