EP300--a miRNA-regulated metastasis suppressor gene in ductal adenocarcinomas of the pancreas.
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.
Mees
Soeren Torge
ST
Department of General and Visceral Surgery, University Hospital of Muenster, Muenster, Germany. soerentorge.mees@ukmuenster.de
Mardin
Wolf Arif
WA
Wendel
Claudia
C
Baeumer
Nicole
N
Willscher
Edith
E
Senninger
Norbert
N
Schleicher
Christina
C
Colombo-Benkmann
Mario
M
Haier
Joerg
J
D000818:Animals; D015153:Blotting, Western; D021441:Carcinoma, Pancreatic Ductal / Q000235:genetics* / Q000473:pathology; D045744:Cell Line, Tumor; D050881:E1A-Associated p300 Protein / Q000235:genetics*; D020869:Gene Expression Profiling; D006801:Humans; D008297:Male; D051379:Mice; D008819:Mice, Nude; D035683:MicroRNAs / Q000235:genetics*; D009362:Neoplasm Metastasis / Q000235:genetics*; D020411:Oligonucleotide Array Sequence Analysis; D010190:Pancreatic Neoplasms / Q000235:genetics* / Q000473:pathology; D020133:Reverse Transcriptase Polymerase Chain Reaction
D035683:MicroRNAs; D050881:E1A-Associated p300 Protein; C494360:EP300 protein, human