AUTOCRINE INDUCTION OF TUMOR PROTEASE PRODUCTION AND INVASION BY A METALLOTHIONEIN-REGULATED TGF-BETA-1 (SER223, 225)
AUTOCRINE INDUCTION OF TUMOR PROTEASE PRODUCTION AND INVASION BY A METALLOTHIONEIN-REGULATED TGF-BETA-1 (SER223, 225)
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DOI：
10.1002/j.1460-2075.1992.tb05205.x
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发表时间：
1992-04-01
期刊：
影响因子：
11.4
通讯作者：
GREENBERG, AH
中科院分区：
文献类型：
--
作者：
SAMUEL, SK;HURTA, RAR;GREENBERG, AH
构建了表达载体，其中TGF-β-1置于金属硫蛋白启动子的控制下。 TGF-β-1 前肽中的 Cys223 和 Cys225 转化为丝氨酸，突变导致前肽解离并分泌生物活性 TGF-β-1 [Brunner,A.M.、Marquardt,H.、Malacko,A.R.、Lioubin,M.N.和 Purchio，A.F. (1989) J.Biol。化学，264，13660-13664]。用该质粒转染纤维肉瘤并选择克隆(17.18)，其中TGF-β-1 mRNA在硫酸锌处理后能够被诱导六倍。这些细胞将生物活性 TGF-β-1 的分泌增加了 14 倍，并且同时出现了 jun-B mRNA 表达的增加，这表明分泌的 TGF-β-1 正在通过自分泌激活来诱导这种早期反应基因。硫酸锌诱导后，肿瘤细胞变得越来越活跃并且能够侵入胶原蛋白凝胶。与不带有TGF-β-1表达载体的亲代肿瘤相反，克隆17.18的硫酸锌刺激增强了胶原酶IV和组织蛋白酶L mRNA水平并且增强了许多溶胶蛋白酶向培养基中的分泌。由于 TGF-β 的作用通常通过抑制蛋白酶转录来减少蛋白水解，因此我们比较了正常亲代成纤维细胞对 ras 转化的纤维肉瘤的反应，并证实 TGF-β 可以极大地增强胶原酶 IV 和组织蛋白酶 L mRNA 水平，而对非转化成纤维细胞几乎没有影响。这些实验表明，诱导TGF-β分泌可以通过自分泌激活增强运动性和蛋白酶产生，从而增加纤维肉瘤的侵袭潜力。
An expression vector was constructed in which TGF-beta-1 was placed under the control of the metallothionein promoter. Cys223 and Cys225 in the TGF-beta-1 propeptide were converted to serines, mutations which result in dissociation of the pro-peptide and secretion of bioactive TGF-beta-1 [Brunner,A.M., Marquardt,H., Malacko,A.R., Lioubin,M.N. and Purchio,A.F. (1989) J. Biol. Chem., 264, 13660-13664]. A fibrosarcoma was transfected with this plasmid and a clone (17.18) was selected in which TGF-beta-1 mRNA was able to be induced six-fold following zinc sulphate treatment. These cells increased the secretion of bioactive TGF-beta-1 14-fold and exhibited a coincidental increase in jun-B mRNA expression, suggesting that secreted TGF-beta-1 was acting to induce this early response gene by autocrine activation. Following zinc sulphate induction, the tumor cells became progressively more motile and able to invade collagen gels. In contrast to parental tumor not bearing the TGF-beta-1 expression vector, zinc sulphate stimulation of clone 17.18 enhanced collagenase IV and procathepsin L mRNA levels and enhanced the secretion of many collagenolytic proteases into the medium. Since the action of TGF-beta generally decreases proteolysis by suppression of protease transcription, we compared the response of normal parental fibroblasts to ras-transformed fibrosarcomas and confirmed that TGF-beta could greatly enhance collagenase IV and procathepsin L mRNA levels while having little effect on non-transformed fibroblasts. These experiments indicate that induction of TGF-beta secretion can enhance motility and protease production through autocrine activation, thus increasing the invasion potential of fibrosarcomas.