Rowley D R, Dang T D, Larsen M, Gerdes M J, McBride L, Lu B
Department of Cell Biology, Baylor College of Medicine, Houston, Texas 77030, USA.
J Biol Chem. 1995 Sep 15;270(37):22058-65. doi: 10.1074/jbc.270.37.22058.
Our previous studies have characterized mesenchyme-derived proteins to identify biologically active proteins and novel markers for stromal cell paracrine action relative to stromal-epithelial interactions. Previous reports have characterized properties of a growth inhibitory activity (to bladder and prostatic epithelial cells), secreted by U4F fetal rat urogenital sinus mesenchymal cells, not cross-reactive with antibodies to known cytokines, and provisionally termed UGIF. The present study reports the characterization, purification, and biological properties of a 20-21-kDa protein responsible for UGIF activity. The 20-21-kDa protein (termed ps20) was purified to near homogeneity, the amino-terminal sequence was determined, and biological properties were characterized in vitro. Amino-terminal sequence analysis indicated no direct matches or regions of homology with known proteins. Purified ps20 induced a linear and saturable inhibition of [3H]thymidine incorporation in PC-3 prostatic carcinoma cells (half-maximal activity at 2.6 nM), inhibited cell proliferation (increased population doubling time from 19.8 to 25.8 h), and induced a 210% stimulation in the synthesis of secreted proteins. These data suggest that ps20 may be a candidate paracrine effector protein and may play a role in stromal-epithelial cell interaction in the prostate gland.
我们之前的研究已对间充质来源的蛋白质进行了表征，以鉴定生物活性蛋白以及与基质 - 上皮相互作用相关的基质细胞旁分泌作用的新型标志物。先前的报道已对一种生长抑制活性（对膀胱和前列腺上皮细胞）的特性进行了表征，该活性由U4F胎鼠泌尿生殖窦间充质细胞分泌，与已知细胞因子的抗体无交叉反应，暂称为UGIF。本研究报道了负责UGIF活性的一种20 - 21 kDa蛋白的表征、纯化及生物学特性。将20 - 21 kDa蛋白（称为ps20）纯化至接近均一性，测定了其氨基末端序列，并在体外对其生物学特性进行了表征。氨基末端序列分析表明与已知蛋白无直接匹配或同源区域。纯化的ps20对PC - 3前列腺癌细胞中[3H]胸苷掺入产生线性且饱和的抑制作用（在2.6 nM时达到半数最大活性），抑制细胞增殖（使群体倍增时间从19.8小时增加到25.8小时），并使分泌蛋白的合成增加210%。这些数据表明ps20可能是一种旁分泌效应蛋白候选物，可能在前列腺的基质 - 上皮细胞相互作用中发挥作用。
