Restoration of SMAD4 by gene therapy reverses the invasive phenotype in pancreatic adenocarcinoma cells
Restoration of SMAD4 by gene therapy reverses the invasive phenotype in pancreatic adenocarcinoma cells
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DOI：
10.1038/sj.onc.1206751
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发表时间：
2003-10-09
期刊：
影响因子：
8
通讯作者：
Horii, A
中科院分区：
文献类型：
--
作者：
Duda, DG;Sunamura, M;Horii, A
SMAD4是响应tgf - β相关配体激活的信号转导通路中的关键辅助因子，调节细胞生长和分化。SMAD4失活在肿瘤中的作用突出了它作为肿瘤抑制基因的作用。然而，在无肿瘤细胞系中，SMAD4基因转移后tgf - β抗增殖途径的恢复是有争议的。在此，我们报道了SMAD4对胰腺肿瘤侵袭和血管生成的抑制作用。腺病毒将该基因转移到SMAD4纯合缺失的人胰腺肿瘤细胞系中，恢复了SMAD4蛋白的表达和功能。虽然SMAD4在体外对肿瘤增殖没有显著影响，但在免疫缺陷小鼠体内却能抑制肿瘤生长。在这种异种移植物环境中，体内肿瘤生长的差异抑制至少部分是通过下调血管内皮生长因子和明胶酶的表达来介导的。我们通过组织学和活体显微镜记录了入侵和血管生成的减少，并在信使和蛋白质水平上获得了机制见解。最后，我们发现SMAD4和ETS-1之间存在负互反调控。ETS-1被认为是肿瘤侵袭的标志。在SMAD4缺失后，我们在胰腺肿瘤细胞中检测到高水平的ETS-1表达，这表明胰腺肿瘤向侵袭性表型转变。
SMAD4 is a critical cofactor in signal transduction pathways activated in response to transforming growth factor-beta (TGF-beta)-related ligands, regulating cell growth and differentiation. The roles played by SMAD4 inactivation in tumours highlighted it as a tumour-suppressor gene. However, restoration of the TGF-beta antiproliferative pathway following SMAD4 gene transfer in null-tumour cell lines is controversial. Herein, we report the inhibitory effects of SMAD4 on pancreatic tumour invasion and angiogenesis. Adenoviral transfer of this gene in a panel of SMAD4 homozygous-deleted human pancreatic tumour cell lines restored SMAD4 protein expression and function. Although it did not affect proliferation significantly in vitro, SMAD4 inhibited in vivo tumour growth in immunodeficient mice. In this xenograft setting, differential suppression of tumour growth in vivo was mediated, at least in part, through downregulation of vascular endothelial growth factor and expression of gelatinases. We documented the reduced invasion and angiogenesis histologically and by intravital microscopy, and gained mechanistic insight at the messenger and protein level. Finally, we found a negative reciprocal regulation between SMAD4 and ETS-1. ETS-1 is considered a marker for tumour invasion. Upon SMAD4 deletion, we detected high expression levels of ETS-1 in pancreatic tumour cells, suggesting the shift of the pancreatic tumour toward an invasive phenotype.