Ismair M G, Ries C, Lottspeich F, Zang C, Kolb H J, Petrides P E
Molecular Oncology Laboratory, Department of Medicine III, University of Munich Medical School Grosshadern, Germany.
Leukemia. 1998 Jul;12(7):1136-43. doi: 10.1038/sj.leu.2401042.
Matrix metalloproteinases have been reported to be involved in tumor cell invasion and metastasis. Dissemination of malignant cells in acute myeloid leukemia (AML) may be mediated by similar mechanisms. Here, we report, that the t(15/17)+ acute promyelocytic leukemia (APL) cell line NB4 constitutively expresses and releases the proenzyme form of matrix metalloproteinase-9 (MMP-9, 92 kDa type IV collagenase/gelatinase, gelatinase B), as well as tissue inhibitor of metalloproteinases-1 (TIMP-1). Both proteins were identified by N-terminal amino acid sequence analysis after purification using gelatin Sepharose affinity chromatography. Whereas 12-O-tetradecanoylphorbol-13 acetate (TPA) increased both MMP-9 and TIMP-1 mRNA levels, tumor necrosis factor-alpha (TNF-alpha) stimulated only MMP-9 gene expression in a dose- and time-dependent manner. Neutralizing monoclonal antibodies (MoABs) to TNF-alpha (anti-TNF-alpha) decreased the constitutive and TPA-dependent expression of MMP-9 but did not influence TIMP-1 expression, either in unstimulated or in TPA-treated NB4 cells. FACS analyses showed that NB4 cells express both TNF receptor 1 (TNF-R1) and TNF-R2 to a similar extent. Blocking MoABs against TNF-R 1 (anti-TNF-R1) decreased the constitutive expression of MMP-9, whereas anti-TNF-R2 had almost no effect. Our results show, that in NB4 cells the expression of MMP-9 but not of TIMP-1 is maintained by autocrine stimulation with TNF-alpha. Thus, leukemic cells may be enabled to leave the bone marrow and infiltrate peripheral tissues by a dysfunction in the regulation of the MMP-9:TIMP-1 equilibrium, possibly triggered through autostimulation by TNF-alpha.
据报道，基质金属蛋白酶参与肿瘤细胞的侵袭和转移。急性髓系白血病（AML）中恶性细胞的播散可能由类似机制介导。在此，我们报道t(15/17)+急性早幼粒细胞白血病（APL）细胞系NB4组成性表达并释放基质金属蛋白酶-9（MMP-9，92 kDa IV型胶原酶/明胶酶，明胶酶B）的酶原形式以及金属蛋白酶组织抑制剂-1（TIMP-1）。使用明胶琼脂糖亲和层析纯化后，通过N端氨基酸序列分析鉴定了这两种蛋白质。虽然12-O-十四烷酰佛波醇-13-乙酸酯（TPA）增加了MMP-9和TIMP-1的mRNA水平，但肿瘤坏死因子-α（TNF-α）仅以剂量和时间依赖性方式刺激MMP-9基因表达。抗TNF-α的中和单克隆抗体（MoABs）降低了MMP-9的组成性和TPA依赖性表达，但在未刺激或TPA处理的NB4细胞中均不影响TIMP-1的表达。流式细胞术分析表明，NB4细胞以相似程度表达TNF受体1（TNF-R1）和TNF受体2（TNF-R2）。抗TNF-R1的阻断性MoABs降低了MMP-9的组成性表达，而抗TNF-R2几乎没有作用。我们的结果表明，在NB4细胞中，MMP-9而非TIMP-1的表达通过TNF-α的自分泌刺激得以维持。因此，白血病细胞可能通过MMP-9:TIMP-1平衡调节功能障碍而能够离开骨髓并浸润外周组织，这种功能障碍可能是由TNF-α的自刺激触发的。
