Cleavage of lumican by membrane-type matrix metalloproteinase-1 abrogates this proteoglycan-mediated suppression of tumor cell colony formation in soft agar
Cleavage of lumican by membrane-type matrix metalloproteinase-1 abrogates this proteoglycan-mediated suppression of tumor cell colony formation in soft agar
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DOI：
10.1158/0008-5472.can-04-1038
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发表时间：
2004-10-01
期刊：
影响因子：
11.2
通讯作者：
Sato, H
中科院分区：
文献类型：
--
作者：
Li, YY;Aoki, T;Sato, H
通过表达克隆方法从人胎盘 cDNA 文库中鉴定出富含亮氨酸的小蛋白多糖 lumican，作为与膜型基质金属蛋白酶-1 (MT1-MMP) 相互作用的基因产物。 HEK293T细胞中MT1-MMP与lumican的共表达降低了分泌到培养基中的lumican的浓度，并且通过添加MMP抑制剂BB94消除了这种降低。来自牛角膜的 Lumican 蛋白和与谷胱甘肽 S-转移酶融合的重组 Lumican 核心蛋白被证明可被重组 MT1-MMP 在多个位点切割。 HEK293 细胞中 lumican 的瞬时表达诱导肿瘤抑制基因产物 p21/Waf-1 的表达，这种表达可通过 MT1-MMP 的共表达以及培养基中 lumican 浓度的降低而消除。 HeLa 细胞中 lumican 的稳定表达诱导了 p21 的表达和软琼脂中集落形成的减少，而这两种情况均被 MT1-MMP 的表达所消除。稳定转染lumican cDNA（HT1080/Lum）的HT1080纤维肉瘤细胞，表达内源性MT1-MMP，分泌中等水平的lumican；然而，用 BB94 处理 HT1080/Lum 细胞会导致培养基中 lumican 的积累。 HT1080/Lum中p21的表达水平与分泌的lumican的浓度成正比，并且与软琼脂中的集落形成呈反向相关。这些结果表明，MT1-MMP 通过降解这种蛋白多糖，消除软琼脂中 lumican 介导的肿瘤细胞集落形成抑制，蛋白多糖通过诱导 p21 下调它。
The small leucine-rich proteoglycan lumican was identified from a human placenta cDNA library by the expression cloning method as a gene product that interacts with membrane-type matrix metalloproteinase-1 (MT1-MMP). Coexpression of MT1-MMP with lumican in HEK293T cells reduced the concentration of lumican secreted into culture medium, and this reduction was abolished by addition of the MMP inhibitor BB94. Lumican protein from bovine cornea and recombinant lumican core protein fused to glutathione S-transferase was shown to be cleaved at multiple sites by recombinant MT1-MMP. Transient expression of lumican in HEK293 cells induced expression of tumor suppressor gene product p21/Waf-1, which was abrogated by the coexpression of MT1-MMP concomitant with a reduction in lumican concentration in culture medium. Stable expression of lumican in HeLa cells induced expression of p21 and reduction of colony formation in soft agar, which were both abolished by the expression of MT1-MMP. HT1080 fibrosarcoma cells stably transfected with the lumican cDNA (HT1080/Lum), which express endogenous MT1-MMP, secreted moderate levels of lumican; however, treatment of HT1080/Lum cells with BB94 resulted in accumulation of lumican in culture medium. The expression levels of p21 in HT1080/Lum were proportional to the concentration of secreted lumican and showed reverse corelation with colony formation in soft agar. These results suggest that MT1-MMP abrogates lumican-mediated suppression of tumor cell colony formation in soft agar by degrading this proteoglycan, which down-regulates it through the induction of p21.