Secretion of prosaposin, a multifunctional protein, by breast cancer cells
Secretion of prosaposin, a multifunctional protein, by breast cancer cells
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DOI：
10.1016/s0304-4165(99)00036-7
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发表时间：
1999-05-24
影响因子：
3
通讯作者：
Patton, S
中科院分区：
文献类型：
--
作者：
Campana, WM;O'Brien, JS;Patton, S
用Western blotting和三种抗体的免疫检测方法检测乳腺癌细胞(MDA231 MDA435，MCF-7)条件培养液中存在于牛奶中的溶酶体蛋白丙皂苷。在这些细胞和SV40转化的乳腺上皮细胞HBL100的培养液中很容易检测到它，但在人神经肿瘤细胞(SK-N-MC)的培养液中不能检测到它。在培养的MCF-7细胞中，随着时间的推移，丙皂素的分泌模式与另一种存在于牛奶中的溶酶体蛋白原D的分泌模式非常相似。添加17β-雌二醇(0.1-100 nM)的培养液在48h后呈剂量依赖性地增加这两种蛋白的分泌，而对细胞存活率没有影响。17β-雌二醇对细胞分泌的影响可能与丙皂苷在细胞分化和细胞死亡保护中的营养活性有关。与肿瘤环境中的其他溶酶体蛋白(如Proathepsin D)相结合，丙皂苷可能是一个因素，通过促进膜糖脂的水解来消除肿瘤转移的障碍，已知的乳腺癌细胞分泌的乳蛋白数量正在增加。有证据表明，在正常的、非哺乳期的乳房中，至少有一部分可能是以内分泌方式分泌的。(C)1999 Elsevier Science B.V.保留所有权利。
Western blotting and immunodetection with three antibodies were used to probe conditioned media of breast cancer cells (MDA231 MDA435, MCF-7) for prosaposin, a lysosomal protein that occurs in milk. It was readily detected in media from these cells, and from that of an sv40-transformed mammary epithelial cell, HBL100, but not from medium of human neural tumor cells (SK-N-MC). In cultures of MCF-7 cells, the prosaposin pattern of secretion over time closely resembled that of procathepsin D, another lysosomal protein occurring in milk. Supplementing medium with 17 beta-estradiol (0.1-100 nM) dose dependently increased secretion of both proteins after 48 h without changes in cell viability. The influence of 17 beta-estradiol on secretion could play a role in the trophic activity of prosaposin in cellular differentiation and cell death protection. In concert with other lysosomal proteins in the tumor environment, such as procathepsin D, prosaposin may be a factor in eliminating barriers to tumor metastasis by facilitating hydrolysis of membrane glycolipids, The number of milk proteins known to be secreted by breast cancer cells is growing. There is evidence that at least some of these may be secreted in an endocrine manner in the normal, non-lactating breast. (C) 1999 Elsevier Science B.V. All rights reserved.