Rochefort H, Capony F, Augereau P, Cavailles V, Garcia M, Morisset M, Freiss G, Maudelonde T, Vignon F
Unité d'Endocrinologie Cellulaire et Moléculaire de l'INSERM (U 158), Montpellier, France.
Int J Rad Appl Instrum B. 1987;14(4):377-84. doi: 10.1016/0883-2897(87)90015-8.
We have studied estrogen-regulated proteins in an attempt to understand the mechanism by which estrogens stimulate cell proliferation and mammary carcinogenesis. In estrogen receptor positive human breast cancer cell lines (MCF7, ZR75-1) estrogens specifically increase the production into the culture medium of a 52,000 daltons (52K) glycoprotein. Several high affinity monoclonal antibodies to the partially purified secretory 52K protein have allowed to purify to homogeneity this protein and its cellular processed products. The 52K protein has been identified as the secreted precursor of a cathepsin-D like protease bearing mannose-6-phosphate signals and routed to lysosomes via mannose-6-phosphate receptor. The protease is mitogenic in vitro on estrogen deprived MCF7 cells and is able to degrade basement membrane and proteoglycans following its activation. The cellular related proteins, as detected by immunohistochemistry and immunoassay are more concentrated in proliferative mammary ducts than in resting ducts and their concentration in breast cancer cytosol appears to be more correlated with lymph nodes invasion and disease free survival (with S. Thorpe, Copenhagen) than with the estrogen receptor (RE) level. The protein is also produced constitutively by RE-negative cell lines, while in some antiestrogen resistant variants, it becomes inducible by tamoxifen, contrary to the wild type MCF7 cells. Cloning of its cDNA in lambda gt11 has allowed to show that the mRNA is rapidly induced by estrogens and to sequence the protein and compare it to that of the normal human kidney cathepsin-D.(ABSTRACT TRUNCATED AT 250 WORDS)
我们研究了雌激素调节蛋白，试图了解雌激素刺激细胞增殖和引发乳腺癌的机制。在雌激素受体阳性的人乳腺癌细胞系（MCF7、ZR75-1）中，雌激素能特异性增加一种52,000道尔顿（52K）糖蛋白分泌到培养基中的量。针对部分纯化的分泌型52K蛋白的几种高亲和力单克隆抗体，使得我们能够将该蛋白及其细胞加工产物纯化至同质。52K蛋白已被鉴定为一种组织蛋白酶D样蛋白酶的分泌前体，该蛋白酶带有甘露糖-6-磷酸信号，并通过甘露糖-6-磷酸受体被转运至溶酶体。这种蛋白酶在体外对雌激素剥夺的MCF7细胞具有促有丝分裂作用，激活后能够降解基底膜和蛋白聚糖。通过免疫组织化学和免疫测定检测到的细胞相关蛋白，在增殖的乳腺导管中比在静止的导管中更集中，并且它们在乳腺癌细胞溶质中的浓度似乎与淋巴结侵袭和无病生存期（与哥本哈根的S. Thorpe合作）的相关性比与雌激素受体（RE）水平的相关性更高。RE阴性细胞系也能组成性产生这种蛋白，而在一些抗雌激素耐药变体中，与野生型MCF7细胞相反，它可被他莫昔芬诱导产生。将其cDNA克隆到λgt11中，使得我们能够证明mRNA可被雌激素快速诱导，并对该蛋白进行测序，还能将其与正常人肾组织蛋白酶D的序列进行比较。（摘要截短至250字）
