Wołczynski S, Surazyński A, Swiatecka J, Pałka J
Department of Gynecological Endocrinology, Medical Academy of Białystok, Skłodowskiej 24A, 15-276 Białystok, Poland.
Gynecol Endocrinol. 2001 Jun;15(3):225-33.
We compared the effects of different concentrations of raloxifene (1, 4 and 10 microM) on collagen biosynthesis, gelatinolytic and prolidase activities and matrix metalloproteinase (MMP) expression (MMP-2 and MMP-9) in estradiol-stimulated (2 nM) breast cancer MCF-7 cells. Raloxifene inhibited in a dose-dependent manner the proliferation of MCF-7 cells, independently of the presence or absence of estradiol in the growth medium. Raloxifene at concentrations of 1 microM and 4 microM inhibited collagen biosynthesis by about 10-fold and prolidase activity by about 50%, while at a concentration of 10 microM it inhibited these processes by only about 25%. This phenomenon was accompanied by differences in gelatinolytic activity and MMP (MMP-2 and MMP-9) expression as demonstrated by zymography and Western immunoblot analysis, respectively. In estrogen-stimulated MCF-7 cells, cultured in the presence of 1 microM raloxifene, a dramatic increase in the activity of both collagenases was found. In contrast, addition of raloxifene at a concentration of 10 microM to the medium of the cells resulted in restoration of gelatinolytic activity to that found in control cells. Similarly, but at both doses (1 and 10 microM), raloxifene was able to reduce MMP-2 expression in the cells. However, when used alone (without estradiol) a concentration of 1 microM raloxifene strongly stimulated MMP-2 expression, while at a concentration of 10 microM the effect was not observed. In the case of MMP-9, only trace amounts of this gelatinase were detected, although in contrast to MMP-2, an increase in its expression was noticed at a concentration of 10 microM raloxifene. The data raise the possibility that in estrogen-stimulated MCF-7 cells, raloxifene at low concentrations (1 and 4 microM) evokes antiestrogenic effect on collagen biosynthesis and prolidase activity on the one hand, and an estrogenic effect on gelatinolytic activity on the other, while at higher concentrations (about 10 microM) it evokes an estrogenic effect on collagen biosynthesis and prolidase activity, and an antiestrogenic effect on gelatinolytic activity. Our data suggest that the effects of raloxifene on collagen synthesis, prolidase and metalloproteinase activities in breast cancer may explain its role in the prevention of breast cancer development.
我们比较了不同浓度（1、4和10微摩尔）的雷洛昔芬对雌二醇刺激（2纳摩尔）的乳腺癌MCF - 7细胞中胶原蛋白生物合成、明胶酶解活性和脯氨酰二肽酶活性以及基质金属蛋白酶（MMP）表达（MMP - 2和MMP - 9）的影响。雷洛昔芬以剂量依赖的方式抑制MCF - 7细胞的增殖，与生长培养基中是否存在雌二醇无关。1微摩尔和4微摩尔浓度的雷洛昔芬分别使胶原蛋白生物合成抑制约10倍，脯氨酰二肽酶活性抑制约50%，而在10微摩尔浓度时，它仅使这些过程抑制约25%。这种现象伴随着明胶酶解活性和MMP（MMP - 2和MMP - 9）表达的差异，分别通过酶谱分析和Western免疫印迹分析得以证明。在存在1微摩尔雷洛昔芬的情况下培养的雌激素刺激的MCF - 7细胞中，发现两种胶原酶的活性都显著增加。相反，向细胞培养基中添加10微摩尔浓度的雷洛昔芬导致明胶酶解活性恢复到对照细胞中的水平。同样，但在两种剂量（1和10微摩尔）下，雷洛昔芬都能够降低细胞中MMP - 2的表达。然而，单独使用（无雌二醇）时，1微摩尔浓度的雷洛昔芬强烈刺激MMP - 2的表达，而在10微摩尔浓度时未观察到这种效果。对于MMP - 9，仅检测到微量的这种明胶酶，尽管与MMP - 2相反，在10微摩尔浓度的雷洛昔芬下其表达有所增加。这些数据提出了一种可能性，即在雌激素刺激的MCF - 7细胞中，低浓度（1和4微摩尔）的雷洛昔芬一方面对胶原蛋白生物合成和脯氨酰二肽酶活性产生抗雌激素作用，另一方面对明胶酶解活性产生雌激素作用，而在较高浓度（约10微摩尔）时，它对胶原蛋白生物合成和脯氨酰二肽酶活性产生雌激素作用，对明胶酶解活性产生抗雌激素作用。我们的数据表明，雷洛昔芬对乳腺癌中胶原蛋白合成、脯氨酰二肽酶和金属蛋白酶活性的影响可能解释了它在预防乳腺癌发展中的作用。
