Hofmann A, Laue S, Rost A K, Scherbaum W A, Aust G
Department of Internal Medicine III, University of Leipzig, Germany.
Thyroid. 1998 Mar;8(3):203-14. doi: 10.1089/thy.1998.8.203.
Thyroid cancer can degrade basement membranes and invade tissues. This depends on a cascade of matrix metalloproteinases involving membrane-type 1 matrix metalloproteinase (MT1-MMP), MMP-2, and MMP-9. We analyzed the expression and role of these MMPs and their specific inhibitors TIMP-2 and TIMP-3 in human highly purified thyroid epithelial, C 643, HTh 74, SW 1736, and 8505 C thyroid carcinoma and thyroid-derived fibroblast cell cultures. The effect of phorbol-myristate acetate (PMA), and of the inflammatory cytokines interleukin-1 (IL-1) and tumor necrosis factor-alpha (TNF-alpha) on MMP and TIMP mRNA levels were monitored by semiquantitative reverse transcriptase-polymerase chain reaction (RT-PCR) including an internal homologous competitor fragment. The highest MT1-MMP mRNA levels were found in thyroid-derived fibroblasts. The MT1-MMP mRNA expression was increased up to 10-fold by PMA, while all other growth factors tested had only negligible effects. The thyroid carcinoma cells themselves did not seem to play a crucial role in the production of MT1-MMP in thyroid tumors. Higher MMP-2 mRNA levels were found in all cell types investigated. The highest MMP-2 mRNA levels were determined in thyroid-derived fibroblasts and HTh 74 cells. We found a lack of MMP-2 response to IL-1, TNF-alpha, and phorbol esters. In unstimulated cells, MMP-9 mRNA was found near the detection limit or at low levels. In nearly all cell types, treatment with PMA, IL-1, and TNF-alpha caused an increase of the MMP-9 mRNA levels. The results of basal and stimulated MMP-2 and MMP-9 mRNA expression were confirmed at the protein level by gelatin zymography. TIMP-2 and TIMP-3 mRNAs were expressed at high levels. In contrast to the basal TIMP-3 mRNA levels, which varied over a great range, there were no striking differences the cell types from analyzing TIMP-2 mRNA. There were no or only slight stimulatory effects on TIMP-2 and TIMP-3 mRNA expression by IL-1, TNF-alpha, and PMA. Taken together, most enzymes of the MT-MMP/MMP class of proteases facilitating invasion of thyroid tumor cells seem to have been produced by fibroblasts, not by the tumor cells themselves. However, some dedifferentiated thyroid tumor cell lines may be capable of secreting some of these enzymes, as in the case of HTh 74 cells.
甲状腺癌能够降解基底膜并侵袭组织。这依赖于一系列基质金属蛋白酶，包括膜型1基质金属蛋白酶（MT1-MMP）、MMP-2和MMP-9。我们分析了这些基质金属蛋白酶及其特异性抑制剂TIMP-2和TIMP-3在人高度纯化的甲状腺上皮细胞、C 643、HTh 74、SW 1736和8505 C甲状腺癌细胞以及甲状腺来源的成纤维细胞培养物中的表达及作用。通过包括内部同源竞争片段的半定量逆转录聚合酶链反应（RT-PCR）监测佛波酯肉豆蔻酸乙酸酯（PMA）、炎性细胞因子白细胞介素-1（IL-1）和肿瘤坏死因子-α（TNF-α）对基质金属蛋白酶和TIMP mRNA水平的影响。在甲状腺来源的成纤维细胞中发现MT1-MMP mRNA水平最高。PMA可使MT1-MMP mRNA表达增加至10倍，而所测试的所有其他生长因子的影响可忽略不计。甲状腺癌细胞本身似乎在甲状腺肿瘤中MT1-MMP的产生中不起关键作用。在所有研究细胞类型中均发现较高的MMP-2 mRNA水平。在甲状腺来源的成纤维细胞和HTh 74细胞中测定到最高的MMP-2 mRNA水平。我们发现MMP-2对IL-1、TNF-α和佛波酯无反应。在未刺激的细胞中，MMP-9 mRNA接近检测限或处于低水平。在几乎所有细胞类型中，用PMA、IL-1和TNF-α处理均可导致MMP-9 mRNA水平升高。通过明胶酶谱法在蛋白质水平证实了基础和刺激状态下MMP-2和MMP-9 mRNA表达的结果。TIMP-2和TIMP-3 mRNA高水平表达。与基础TIMP-3 mRNA水平在很大范围内变化不同，分析TIMP-2 mRNA时各细胞类型之间没有显著差异。IL-1、TNF-α和PMA对TIMP-2和TIMP- mRNA表达没有或仅有轻微的刺激作用。综上所述，促进甲状腺肿瘤细胞侵袭的MT-MMP/MMP类蛋白酶中的大多数似乎是由成纤维细胞产生的，而非肿瘤细胞自身。然而，一些去分化的甲状腺肿瘤细胞系可能能够分泌其中一些酶，如HTh 74细胞的情况。
