Mees Soeren Torge, Mardin Wolf Arif, Wendel Claudia, Baeumer Nicole, Willscher Edith, Senninger Norbert, Schleicher Christina, Colombo-Benkmann Mario, Haier Joerg
Department of General and Visceral Surgery, University Hospital of Muenster, Muenster, Germany.
Int J Cancer. 2010 Jan 1;126(1):114-24. doi: 10.1002/ijc.24695.
Genetic and epigenetic alterations during development of pancreatic ductal adenocarcinomas (PDACs) are well known. This study investigates genetic and epigenetic data together with tumor biology to find specific alterations responsible for metastasis formation. Using 16 human PDAC cell lines in a murine orthotopic PDAC model, local infiltration and metastatic spread were assessed by standardized dissemination scores. The cell lines were further classified into 3 hierarchical groups according to their metastatic potential. Their mRNA and microRNA (miRNA) expression was profiled via mRNA-microarray as well as Taqman Low Density Array, and validated by single quantitative RT-PCR and Western blotting. In the highly metastatic group, a significant induction of EP300 targeting miRNAs miR-194 (fold change: 26.88), miR-200b (fold change: 61.65), miR-200c (fold change: 19.44) and miR-429 (fold change: 21.67) (p < 0.05) was detected. Corresponding to this, decreased expression of EP300 mRNA (p < 0.0001) and protein (p < 0.05) were detected in the highly metastatic PDAC cell lines with liver metastases compared to the nonmetastatic or marginally metastatic cell lines, while no correlation with local tumor growth was found. In conclusion, epigenetic alterations with upregulated EP300 targeting miRNAs miR-194, miR-200b, miR-200c and miR-429 are related to reduced EP300 mRNA and protein in PDAC. These results demonstrate that miRNAs might be able to modulate the expression of metastasis-specific suppressor genes and metastatic behavior in PDAC, suggesting diagnostic and therapeutic opportunities for EP300 and its targeting miRNAs in PDAC.
胰腺导管腺癌（PDAC）发生发展过程中的基因和表观遗传改变已广为人知。本研究将基因和表观遗传数据与肿瘤生物学相结合，以寻找导致转移形成的特定改变。在小鼠原位PDAC模型中使用16种人PDAC细胞系，通过标准化的播散评分评估局部浸润和转移扩散情况。根据转移潜能将细胞系进一步分为3个层次组。通过mRNA微阵列以及Taqman低密度阵列对其mRNA和微小RNA（miRNA）表达进行分析，并通过单定量逆转录PCR和蛋白质免疫印迹进行验证。在高转移组中，检测到EP300靶向的miRNA miR-194（倍数变化：26.88）、miR-200b（倍数变化：61.65）、miR-200c（倍数变化：19.44）和miR-429（倍数变化：21.67）有显著诱导（p<0.05）。与此相应，与非转移或微转移细胞系相比，在有肝转移的高转移PDAC细胞系中检测到EP300 mRNA（p<0.0001）和蛋白（p<0.05）表达降低，而未发现与局部肿瘤生长相关。总之，EP300靶向的miRNA miR-194、miR-200b、miR-200c和miR-429上调的表观遗传改变与PDAC中EP300 mRNA和蛋白减少有关。这些结果表明，miRNA可能能够调节PDAC中转移特异性抑制基因的表达和转移行为，提示EP300及其靶向miRNA在PDAC中的诊断和治疗机会。
