Shen Xiao-Ming, Wu Yu-Peng, Feng Yan-Bin, Luo Man-Li, Du Xiao-Li, Zhang Yu, Cai Yan, Xu Xin, Han Ya-Ling, Zhang Xun, Zhan Qi-Min, Wang Ming-Rong
State Key Laboratory of Molecular Oncology, Cancer Institute (Hospital), Peking Union Medical College and Chinese Academy of Medical Sciences, Beijing 100021, China.
Clin Exp Metastasis. 2007;24(7):541-50. doi: 10.1007/s10585-007-9091-9. Epub 2007 Aug 1.
To gain insights into metastatic mechanisms in esophageal squamous cell carcinoma (ESCC), we established sublines (MLuB1 and MLuC1) with different capacity of spontaneous lung metastasis by subcutaneous injection of a human ESCC cell line (EC 9706) into nude mices. The incidence of the mice with lung metastasis produced by MLuC1 (87%) was significantly higher than that of MLuB1 (22%). The gene expression profiles of the two sublines were compared with cDNA arrays containing 5,000 known genes, and 47 genes were differentially expressed > or =2.0 fold. Laminin-5gamma2 chain (Ln-5gamma2) was one of the up-regulated genes in MLuC1 cells. Proteolytically processed forms of gamma2 are known to promote migration of a multitude of epithelial cells in vitro. Western-blotting analysis revealed that degraded fragments of Ln-5gamma2 and active form of membrane-type matrix metalloproteinase-1 (MT1-MMP) in MLuC1 was significantly higher than those in MLuB1. Expression of MT1-MMP was observed in 60 of 75 Ln-5gamma2-positive carcinoma tissues (80%). Co-expression of the two proteins was significantly associated with depth of invasion (P = 0.012). Moreover, proteolytic fragments of Ln-5gamma2 and active forms of MT1-MMP were frequently found in tumor tissues, whereas in the corresponding normal esophageal tissues there were only intact forms of gamma2 and MT1-MMP. siRNA-mediated silencing of MT1-MMP significantly reduced production of gamma2' and gamma2x in MLuC1 cells and inhibited cell migration. The results suggest that MT1-MMP is an enzyme responsible for Ln-5gamma2 cleavage in ESCC, and interaction between them may play a critical role in promoting invasion and metastasis of human ESCC.
为深入了解食管鳞状细胞癌（ESCC）的转移机制，我们通过将人ESCC细胞系（EC 9706）皮下注射到裸鼠体内，建立了具有不同自发肺转移能力的亚系（MLuB1和MLuC1）。由MLuC1产生的肺转移小鼠发生率（87%）显著高于MLuB1（22%）。将这两个亚系的基因表达谱与包含5000个已知基因的cDNA阵列进行比较，有47个基因的差异表达≥2.0倍。层粘连蛋白-5γ2链（Ln-5γ2）是MLuC1细胞中上调的基因之一。已知γ2的蛋白水解加工形式在体外可促进多种上皮细胞的迁移。蛋白质印迹分析显示，MLuC1中Ln-5γ2的降解片段和膜型基质金属蛋白酶-1（MT1-MMP）的活性形式显著高于MLuB1。在75个Ln-5γ2阳性癌组织中的60个（80%）中观察到MT1-MMP的表达。这两种蛋白的共表达与浸润深度显著相关（P = 0.012）。此外，在肿瘤组织中经常发现Ln-5γ2的蛋白水解片段和MT1-MMP的活性形式，而在相应的正常食管组织中仅存在完整形式的γ2和MT1-MMP。siRNA介导的MT1-MMP沉默显著降低了MLuC1细胞中γ2'和γ2x的产生，并抑制了细胞迁移。结果表明，MT1-MMP是ESCC中负责Ln-5γ2切割的酶，它们之间的相互作用可能在促进人ESCC的侵袭和转移中起关键作用。
