Vasiljeva Olga, Papazoglou Anna, Krüger Achim, Brodoefel Harald, Korovin Matvey, Deussing Jan, Augustin Nicole, Nielsen Boye S, Almholt Kasper, Bogyo Matthew, Peters Christoph, Reinheckel Thomas
Institut für Molekulare Medizin und Zellforschung and Institut für Biometrie und Medizinische Informatik, Albert-Ludwigs-Universität Freiburg, Freiburg, Germany.
Cancer Res. 2006 May 15;66(10):5242-50. doi: 10.1158/0008-5472.CAN-05-4463.
Proteolysis in close vicinity of tumor cells is a hallmark of cancer invasion and metastasis. We show here that mouse mammary tumor virus-polyoma middle T antigen (PyMT) transgenic mice deficient for the cysteine protease cathepsin B (CTSB) exhibited a significantly delayed onset and reduced growth rate of mammary cancers compared with wild-type PyMT mice. Lung metastasis volumes were significantly reduced in PyMT;ctsb(+/-), an effect that was not further enhanced in PyMT;ctsb(-/-) mice. Furthermore, lung colonization studies of PyMT cells with different CTSB genotypes injected into congenic wild-type mice and in vitro Matrigel invasion assays confirmed a specific role for tumor-derived CTSB in invasion and metastasis. Interestingly, cell surface labeling of cysteine cathepsins by the active site probe DCG-04 detected up-regulation of cathepsin X on PyMT;ctsb(-/-) cells. Treatment of cells with a neutralizing anti-cathepsin X antibody significantly reduced Matrigel invasion of PyMT;ctsb(-/-) cells but did not affect invasion of PyMT;ctsb(+/+) or PyMT;ctsb(+/-) cells, indicating a compensatory function of cathepsin X in CTSB-deficient tumor cells. Finally, an adoptive transfer model, in which ctsb(+/+), ctsb(+/-), and ctsb(-/-) recipient mice were challenged with PyMT;ctsb(+/+) cells, was used to address the role of stroma-derived CTSB in lung metastasis formation. Notably, ctsb(-/-) mice showed reduced number and volume of lung colonies, and infiltrating macrophages showed a strongly up-regulated expression of CTSB within metastatic cell populations. These results indicate that both cancer cell-derived and stroma cell-derived (i.e., macrophages) CTSB plays an important role in tumor progression and metastasis.
肿瘤细胞附近的蛋白水解是癌症侵袭和转移的一个标志。我们在此表明，与野生型PyMT小鼠相比，缺乏半胱氨酸蛋白酶组织蛋白酶B（CTSB）的小鼠乳腺肿瘤病毒-多瘤中间T抗原（PyMT）转基因小鼠的乳腺癌发病明显延迟且生长速度降低。PyMT;ctsb(+/-)小鼠的肺转移体积显著减少，在PyMT;ctsb(-/-)小鼠中这一效应并未进一步增强。此外，将不同CTSB基因型的PyMT细胞注射到同基因野生型小鼠中进行肺定植研究以及体外基质胶侵袭试验证实了肿瘤来源的CTSB在侵袭和转移中的特定作用。有趣的是，活性位点探针DCG-04对半胱氨酸组织蛋白酶的细胞表面标记检测到PyMT;ctsb(-/-)细胞上组织蛋白酶X上调。用中和性抗组织蛋白酶X抗体处理细胞可显著降低PyMT;ctsb(-/-)细胞的基质胶侵袭，但不影响PyMT;ctsb(+/+)或PyMT;ctsb(+/-)细胞的侵袭，表明组织蛋白酶X在CTSB缺陷肿瘤细胞中具有补偿功能。最后，采用一种过继转移模型，用PyMT;ctsb(+/+)细胞攻击ctsb(+/+)、ctsb(+/-)和ctsb(-/-)受体小鼠，以探讨基质来源的CTSB在肺转移形成中的作用。值得注意的是，ctsb(-/-)小鼠的肺集落数量和体积减少，浸润的巨噬细胞在转移细胞群体中显示出CTSB的强烈上调表达。这些结果表明，癌细胞来源和基质细胞来源（即巨噬细胞）的CTSB在肿瘤进展和转移中都起着重要作用。
