Division of Haematology and Transfusion Medicine, Paul-Ehrlich-Institut, Paul-Ehrlich-Straße 51-59, 63225 Langen, Germany.
J Cancer Res Clin Oncol. 2012 Apr;138(4):695-703. doi: 10.1007/s00432-011-1139-1. Epub 2012 Jan 12.
Tissue factor (TF), the transmembrane receptor for factor VIIa (FVIIa), has key regulatory functions in coagulation as well as in tumour progression and metastasis. Small-cell lung cancer (SCLC) metastasises more aggressively than non-small-cell lung cancer (NSCLC). Previously, we described the transition of SCLC cell line H69 to adherent growth and TF expression. Here, we explored the differential expression of TF and its functional impact on morphology and matrix metalloproteinase (MMP) secretion.
The constitutional TF expression was evaluated in a panel of established NSCLC and SCLC cell lines. Furthermore, in three stress-selected adherent SCLC H69 cells, TF and MMP expressions were determined by mRNA, protein, and activity measurements. RNA interference-mediated TF down-regulation and FVIIa stimulation were used to study the impact of TF on cellular functions.
NSCLC cells expressed high TF antigen (median 3.75 ng/mg; range 0.31-65.2 ng/mg protein, n = 8), while SCLC expressed none or low TF (median 0.07 ng/mg; range 0-0.39 ng/mg protein, n = 6). However, selected H69 adherent cells markedly expressed TF (range: 4.8-44.3 ng/mg protein, n = 3) and secreted MMP-2 and MMP-9. FVIIa stimulated MMP-2 and MMP-9 secretion in H69adh cells, whereas TF down-regulation diminished MMP-2 and MMP-9 expression and promoted reversion to suspension growth.
Our data show the significance of TF expression in the reversible growth phenotype of H69. Because TF, MMP expression, and adherence are highly relevant to cancer metastasis, this study suggests a novel mechanism of adaptation, thereby adding to the understanding of SCLC biology and its aggressiveness.
组织因子（TF）是因子 VIIa（FVIIa）的跨膜受体，在凝血以及肿瘤进展和转移中具有关键的调节功能。小细胞肺癌（SCLC）比非小细胞肺癌（NSCLC）更具侵袭性。此前，我们描述了 SCLC 细胞系 H69 向贴壁生长和 TF 表达的转变。在这里，我们探索了 TF 的差异表达及其对形态和基质金属蛋白酶（MMP）分泌的功能影响。
在一系列已建立的 NSCLC 和 SCLC 细胞系中评估了 TF 的组成型表达。此外，在三种应激选择的贴壁 SCLC H69 细胞中，通过 mRNA、蛋白质和活性测量来确定 TF 和 MMP 的表达。使用 RNA 干扰介导的 TF 下调和 FVIIa 刺激来研究 TF 对细胞功能的影响。
NSCLC 细胞表达高水平的 TF 抗原（中位数 3.75ng/mg；范围 0.31-65.2ng/mg 蛋白，n=8），而 SCLC 则不表达或低表达 TF（中位数 0.07ng/mg；范围 0-0.39ng/mg 蛋白，n=6）。然而，选定的 H69 贴壁细胞明显表达 TF（范围：4.8-44.3ng/mg 蛋白，n=3）并分泌 MMP-2 和 MMP-9。FVIIa 刺激 H69adh 细胞中 MMP-2 和 MMP-9 的分泌，而 TF 下调则减少 MMP-2 和 MMP-9 的表达并促进恢复为悬浮生长。
我们的数据表明 TF 表达在 H69 的可逆生长表型中的重要性。由于 TF、MMP 表达和粘附与癌症转移高度相关，因此这项研究提出了一种新的适应机制，从而增加了对 SCLC 生物学及其侵袭性的理解。
