Suppression of in vivo tumor growth and induction of suspension cell death by tissue inhibitor of metalloproteinases (TIMP)-3
Suppression of in vivo tumor growth and induction of suspension cell death by tissue inhibitor of metalloproteinases (TIMP)-3
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DOI：
10.1093/carcin/17.9.1805
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发表时间：
1996-09-01
期刊：
影响因子：
4.7
通讯作者：
Sun, Y
中科院分区：
文献类型：
--
作者：
Bian, JH;Wang, YL;Sun, Y
金属蛋白酶组织抑制剂-3（TIMP-3）是TIMP家族基因的一个新成员，最近已被克隆并显示在肿瘤前而非肿瘤小鼠JB 6表皮细胞中表达（Sun艾德等人，1994 Cancer Res.，54，11139）。该基因的这种下调似乎至少部分归因于基因甲基化的改变（Sun等，1995 J. Biol. Chem.，270，19312），然而，关于TIMP-3在人类癌症中的作用知之甚少。我们筛选了几种TIMP-3表达的人类肿瘤细胞系，并发现结肠癌细胞系DLD-1不表达TIMP-3。如果TIMP-3的下调与癌发生有因果关系，则通过转染的再表达可以逆转肿瘤细胞表型，因此，我们在DLD-1细胞中过表达人TIMP-3，TIMP-3转染子在单层培养中显示血清依赖性生长抑制，并以依赖于TIMP-3表达水平的方式降低裸鼠的生长潜力，表达高水平活性hTIMP-3的转染子在皮下注射后完全丧失形成肿瘤的能力。我们还测试了TIMP-3表达细胞和新对照TIMP-3阴性细胞在液体悬浮培养物中生长的能力，因为这两种细胞都在半固体软琼脂中生长。与新对照细胞相比，TIMP-3过表达者形成大的聚集体，随后细胞死亡。这种作用不能被BB 94（一种广谱MMP抑制剂）模拟，我们从这项研究中得出结论，（i）TIMP-3在人结肠癌细胞中的过表达诱导低血清条件下的生长停滞并抑制体内肿瘤生长，（ii）TIMP-3诱导的大聚集体形成和随后的悬浮生长下的细胞死亡不能用其MMP抑制活性来解释。
Tissue inhibitor of metalloproteinases-3(TIMP-3), a novel member of TIMP family genes, has been recently cloned and shown to be expressed in preneoplastic but not in neoplastic mouse JB6 epidermal cells (Sun ed al. 1994 Cancer Res., 54, 11139), This down regulation of the gene appears to be attributable at least in part to alteration of gene methylation (Sun et al, 1995 J. Biol. Chem., 270, 19312), Little is known, however, about the role of TIMP-3 in human cancers, We screened several human tumor cell lines for TIMP-3 expression and found that a colon carcinoma line, DLD-1, did not express TIMP-3, If down regulation of TIMP-3 is causally related to carcinogenesis, re-expression by transfection may reverse the tumor cell phenotype, We therefore overexpressed human TIMP-3 in DLD-1 cells, TIMP-3 transfectants showed a serum-dependent growth inhibition in monolayer culture and a decreased growth potential in nude mice in a manner dependent on the level of TIMP-3 expression, A transfectant expressing a high level of active hTIMP-3 completely lost the ability to form tumors following s.c. injection into nude mice, We also tested TIMP-3 expressing cells and neocontrol TIMP-3 negative cells for their ability to grow in liquid suspension culture, since both cells grew in semi-solid soft agar, As compared to neocontrol cells, TIMP-3 overexpressors formed large aggregates, followed by cell death, This effect was not mimicked by BB94, a broad MMP inhibitor, We conclude from this study that (i) TIMP-3 overexpression in human colon carcinoma cells induces growth arrest in low serum conditions and inhibits in vivo tumor growth and (ii) the TIMP-3-induced large aggregate formation and subsequent cell death under suspension growth cannot be explained by its MMP inhibitory activity.