Angiostatin generation by cathepsin D secreted by human prostate carcinoma cells
Angiostatin generation by cathepsin D secreted by human prostate carcinoma cells
复制标题
DOI：
10.1074/jbc.m005402200
复制
发表时间：
2000-12-08
影响因子：
4.8
通讯作者：
Kuwano, M
中科院分区：
文献类型：
--
作者：
Morikawa, W;Yamamoto, K;Kuwano, M
血管生成抑制素是一种有效的内源性血管生成抑制剂，由肿瘤介导的纤溶酶原蛋白水解产生。人前列腺癌细胞的培养基，当在各种pH值下与纤溶酶原孵育时，产生血管生成抑制肽和微纤溶酶原。负责该反应的酶被纯化并鉴定为组织蛋白酶原D。纯化的组织蛋白酶D原以及组织蛋白酶D在体外在3.0-6.8的pH范围内产生两种具有相同的NH 2-末端氨基酸序列并包含纤溶酶原的kringle 1-4的血管抑制肽，在pH 4.0时最强烈。该反应需要同时将组织蛋白酶原D转化为催化活性的假组织蛋白酶D。通过延长孵育未观察到假组织蛋白酶D向成熟组织蛋白酶D的转化。亲和纯化的血管生成抑制肽在体外和体内均抑制血管生成。重要的是，人乳腺癌细胞分泌的组织蛋白原D显示出比人前列腺癌细胞显著更低的血管抑素生成活性。由于前列腺癌和乳腺癌细胞的去糖基化的组织蛋白酶原D表现出类似的低血管抑素生成活性，这种差异似乎归因于两种细胞类型之间的组织蛋白酶原D分子的碳水化合物结构的差异。前列腺癌患者的精囊液中含有成熟的组织蛋白酶D和组织蛋白酶D原，但不含有假组织蛋白酶D，表明假组织蛋白酶D不是组织蛋白酶D原在体内加工的正常中间体。本研究首次提供证据表明，由人前列腺癌细胞分泌的组织蛋白酶D负责血管抑素的生成，从而防止肿瘤生长和转移的血管生成依赖性生长。
Angiostatin, a potent endogenous inhibitor of angiogenesis, is generated by cancer-mediated proteolysis of plasminogen. The culture medium of human prostate carcinoma cells, when incubated with plasminogen at a variety of pH values, generated angiostatic peptides and miniplasminogen. The enzyme(s) responsible for this reaction was purified and identified as procathepsin D. The purified procathepsin D, as well as cathepsin D, generated two angiostatic peptides having the same NH2-terminal amino acid sequences and comprising kringles 1-4 of plasminogen in the pH range of 3.0-6.8, most strongly at pH 4.0 in vitro. This reaction required the concomitant conversion of procathepsin D to catalytically active pseudocathepsin D. The conversion of pseudocathepsin D to the mature cathepsin D was not observed by the prolonged incubation. The affinity-purified angiostatic peptides inhibited angiogenesis both in vitro and in vivo. Importantly, procathepsin D secreted by human breast carcinoma cells showed a significantly lower angiostatin-generating activity than that by human prostate carcinoma cells. Since deglycosylated procathepsin D from both prostate and breast carcinoma cells exhibited a similar low angiostatin-generating activity, this discrepancy appeared to be attributed to the difference in carbohydrate structures of procathepsin D molecules between the two cell types. The seminal vesicle fluid from patients with prostate carcinoma contained the mature cathepsin D and procathepsin D, but not pseudocathepsin D, suggesting that pseudocathepsin D is not a normal intermediate of procathepsin D processing in vivo. The present study provides evidence for the first time that cathepsin D secreted by human prostate carcinoma cells is responsible for angiostatin generation, thereby causing the prevention of tumor growth and angiogenesis-dependent growth of metastases.