Role for EPS8 in squamous carcinogenesis
Role for EPS8 in squamous carcinogenesis
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DOI：
10.1093/carcin/bgn252
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发表时间：
2009-01-01
期刊：
影响因子：
4.7
通讯作者：
Yeudall, W. Andrew
中科院分区：
文献类型：
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作者：
Wang, Huixin;Patel, Vyomesh;Yeudall, W. Andrew
我们使用模型系统和体内研究了信号中间产物Eps8在肿瘤进展中的作用。HN4原代肿瘤细胞表达低水平的Eps8，与正常角质形成细胞相似，体外对表皮生长因子的反应表现出最小的侵袭性，而HN12细胞表达高水平的Eps8，在体外具有高度的运动性和体内致瘤性。与正常角质形成细胞相比，其他独立的肿瘤细胞株也显示Eps8的表达增加。利用逆转录病毒转导技术，我们获得了表达Eps8(HN4/Eps8)的HN4细胞系，其表达水平与HN12细胞中的表达水平相当。与对照组相比，HN4/Eps8细胞的增殖和迁移增加，基质金属蛋白酶(MMP9)的表达和活性增加，这依赖于蛋白激酶B(AKT)的活性。将直接合成Eps8短发夹状RNA(ShRNA)的质粒导入HN12细胞后，这些细胞中Eps8的表达降低，这与它们在体外迁移和侵袭的能力降低有关。此外，shRNA介导的Eps8基因敲除降低了这些细胞产生的基质金属蛋白酶-9的表达和活性，并降低了基质金属蛋白酶-9的启动子活性。与对照组相比，Eps8基因敲除细胞体内的致瘤性降低，并且降低了基质金属蛋白酶-9的表达。相反，在原位移植试验中，在HN4细胞中过表达Eps8足以诱导这些非致瘤细胞的生长。此外，Eps8在鳞癌临床标本中的表达显示出不同的表达水平，并且与基质金属蛋白酶-9的表达大致平行。这些数据支持Eps8在鳞癌发生中的作用。
We have investigated the role of the signaling intermediate, EPS8, in tumor progression using a model system and in vivo. HN4 primary tumor cells express low levels of EPS8, similar to normal keratinocytes, and show minimal invasion in vitro in response to epidermal growth factor, whereas HN12 cells express high levels of EPS8 and are highly motile in vitro and tumorigenic in vivo. Additional independent tumor cell lines also showed elevated EPS8 expression compared with normal keratinocytes. Using retroviral transduction, we generated HN4 cell lines expressing EPS8 (HN4/EPS8) at levels equivalent to those present in HN12 cells. HN4/EPS8 cells showed increased proliferation and migration compared with controls, together with elevated expression and activity of matrix metalloprotease (MMP)-9, which was dependent on protein kinase B (AKT) activity. Introduction of plasmids that direct synthesis of EPS8 short hairpin RNA (shRNA) into HN12 cells resulted in decreased EPS8 expression in these cells, which correlated with a decrease in their capacity to migrate and invade in vitro. In addition, shRNA-mediated knockdown of EPS8 reduced expression and activity of MMP-9 produced by these cells and reduced MMP-9 promoter activity. EPS8 knockdown cells showed decreased tumorigenicity in vivo compared with controls and lower MMP-9 expression. Conversely, overexpression of EPS8 in HN4 cells was sufficient to induce growth of these non-tumorigenic cells in orthotopic transplantation assays. Furthermore, EPS8 expression in clinical samples of squamous cell carcinoma showed variable expression levels and broadly paralleled expression of MMP-9. The data support a role for EPS8 in squamous carcinogenesis.