Mechanisms of expression of neuroendocrine phenotype in the mammary gland

本研究的目的是阐明嗜铬粒蛋白/分泌粒蛋白mRNA是否在正常乳腺和乳腺肿瘤中表达。使用的乳腺处于休止、妊娠、哺乳期和复旧状态。乳腺肿瘤为纤维腺瘤和腺癌。结果：(1)电镜观察未发现明显的神经内分泌颗粒。(2) CgA、SgI和SgII mRNA的表达在妊娠后期得到检测。CgA mRNA在哺乳期早期也有表达。(3) CgA和SgII mRNA在两种大鼠乳腺肿瘤中均有表达，但SgI mRNA未表达。(4)雌二醇（5、50、500、1000 μg/kg/周，1 ~ 4周）对CgA、SgI和SgII mRNA均无诱导作用。(5)同时检测PRL mRNA。PRL mRNA的表达贯穿妊娠中期至哺乳期。(6)在乳腺肿瘤（纤维腺瘤和腺癌）中也发现了PRL mRNA。

The aim of the present study is to clarify whether chromogranin/secretogranin mRNA expresses in the normal mammary gland and mammary gland tumors. The mammary gland used was under the condition of resting, pregnancy, lactation and involution. The mammary gland tumors were fibroadenoma and adenocarcinoma. Results were (1) No apparent neuroendocrine granules were identified by electronmicroscopical study. (2) CgA, SgI and SgII mRNA expression was identified in the late pregnancy. CgA mRNA expression was additionally found in the early phase of the lactation. (3) CgA and SgII mRNA expression were identified in both of the rat mammary gland tumors, although SgI mRNA expression was not detected. (4) CgA, SgI and SgII mRNA were not induced by treatment of estradiol (5, 50, 500, 1000 μg/kg/week, 1-4 weeks). (5) At the same time, PRL mRNA was examined. PRL mRNA was expressed through mid pregnancy to lacatation. (6) PRL mRNA was also identified in mammary gland tumors (fibroadenoma and adenocarcinoma).