ZEB1 Coordinately Regulates Laminin-332 and β4 Integrin Expression Altering the Invasive Phenotype of Prostate Cancer Cells
ZEB1 Coordinately Regulates Laminin-332 and β4 Integrin Expression Altering the Invasive Phenotype of Prostate Cancer Cells
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DOI：
10.1074/jbc.m110.136044
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发表时间：
2010-10-29
影响因子：
4.8
通讯作者：
Henry, Michael D.
中科院分区：
文献类型：
--
作者：
Drake, Justin M.;Barnes, J. Matthew;Henry, Michael D.
转移涉及癌细胞跨越细胞外基质和细胞屏障的侵袭，并且一个不断发展的主题是上皮-间充质转化（EMT）可以介导侵袭性细胞行为。之前，我们分离并分析了PC-3前列腺癌细胞TEM 4 -18的亚群，发现这些细胞更有效地侵入内皮屏障，并在体内表现出增强的转移性定植。这些细胞的跨内皮迁移依赖于ZEB 1的表达，ZEB 1是一种已知的EMT调节因子。令人惊讶的是，在涉及基质屏障的测定中，这些细胞的侵袭性比亲本PC-3细胞低得多。在这里，我们报告说，TEM 4 -18细胞表达层粘连蛋白-332（β 3和γ 2）的两个亚基的水平显着降低，外源性层粘连蛋白-332，或与层粘连蛋白-332表达细胞共培养，挽救了这些细胞的体外侵袭表型。稳定敲除前列腺癌细胞中的ZEB 1上调LAMC 2和ITGB 4 mRNA和蛋白，并导致Transwell迁移的伴随增加。使用染色质免疫沉淀（ChIP），我们发现ZEB 1直接与LAMC 2和ITGB 4的启动子相互作用。这些结果为临床前列腺癌标本中观察到的层粘连蛋白-332减少提供了新的分子基础，并证明了EMT在侵袭性细胞行为中的上下文依赖性作用。
Metastasis involves the invasion of cancer cells across both the extracellular matrix and cellular barriers, and an evolving theme is that epithelial-to-mesenchymal transition (EMT) may mediate invasive cellular behavior. Previously, we isolated and analyzed a subpopulation of PC-3 prostate cancer cells, TEM4-18, and found that these cells both invaded an endothelial barrier more efficiently and exhibited enhanced metastatic colonization in vivo. Transendothelial migration of these cells depended on expression of ZEB1, a known regulator of EMT. Surprisingly, these cells were much less invasive than parental PC-3 cells in assays that involve matrix barriers. Here, we report that TEM4-18 cells express significantly reduced levels of two subunits of laminin-332 (beta 3 and gamma 2) and that exogenous laminin-332, or co-culture with laminin-332-expressing cells, rescues the in vitro invasion phenotype in these cells. Stable knockdown of ZEB1 in prostate cancer cells up-regulated LAMC2 and ITGB4 mRNA and protein and resulted in a concomitant increase in Transwell migration. Using chromatin immunopre-cipitation (ChIP), we show that ZEB1 directly interacts with the promoters of LAMC2 and ITGB4. These results provide a novel molecular basis for reduced laminin-332 observed in clinical prostate cancer specimens and demonstrate a context-dependent role for EMT in invasive cellular behavior.