Inactivation of Ink4a/Arf leads to deregulated expression of miRNAs in K-Ras transgenic mouse model of pancreatic cancer.
Human pancreatic cancer (PC) is an aggressive disease, which has been recapitulated in transgenic animal model that provides unique opportunity for mechanistic understanding of disease progression and also for testing the efficacy of novel therapeutics. Emerging evidence suggests deregulated expression of microRNAs (miRNAs) in human PC, and thus we investigated the expression of miRNAs in pancreas tissues obtained from transgenic mouse models of K-Ras (K), Pdx1-Cre (C), K-Ras;Pdx1-Cre (KC), and K-Ras;Pdx1-Cre;INK4a/Arf (KCI), initially from pooled RNA samples using miRNA profiling, and further confirmed in individual specimens by quantitative RT-PCR. We found over-expression of miR-21, miR-221, miR-27a, miR-27b, and miR-155, and down-regulation of miR-216a, miR-216b, miR-217, and miR-146a expression in tumors derived from KC and KCI mouse model, which was consistent with data from KCI-derived RInk-1 cells. Mechanistic investigations revealed a significant induction of EGFR, K-Ras, and MT1-MMP protein expression in tissues from both KC and KCI mouse compared to tissues from K or C, and these results were consistent with similar findings in RInk-1 cells compared to human MIAPaCa-2 cells. Furthermore, miR-155 knock-down in RInk-1 cells resulted in the inhibition of cell growth and colony formation consistent with down-regulation of EGFR, MT1-MMP, and K-Ras expression. In addition, miR-216b which target Ras, and forced re-expression of miR-216b in RInk-1 cells showed inhibition of cell proliferation and colony formation, which was correlated with reduced expression of Ras, EGFR, and MT1-MMP. These findings suggest that these models would be useful for preclinical evaluation of novel miRNA-targeted agents for designing personalized therapy for PC.
Department of Oncology, Karmanos Cancer Institute, Wayne State University, Detroit, MI, USA.
Shadan
S
Ali
Sanjeev
S
Banerjee
Farah
F
Logna
Bin
B
Bao
Philip A
PA
Philip
Murray
M
Korc
Fazlul H
FH
Sarkar
D000818:Animals; D002460:Cell Line; D049109:Cell Proliferation; D019941:Cyclin-Dependent Kinase Inhibitor p16 / Q000235:genetics / Q000378:metabolism*; D015536:Down-Regulation / Q000235:genetics*; D066246:ErbB Receptors / Q000235:genetics / Q000378:metabolism; D015972:Gene Expression Regulation, Neoplastic / Q000235:genetics; D011905:Genes, ras; D006801:Humans; D053511:Matrix Metalloproteinase 14 / Q000235:genetics / Q000378:metabolism; D051379:Mice; D008822:Mice, Transgenic / Q000235:genetics / Q000378:metabolism; D035683:MicroRNAs / Q000235:genetics* / Q000378:metabolism; D010179:Pancreas / Q000378:metabolism; D010190:Pancreatic Neoplasms / Q000235:genetics* / Q000378:metabolism; D013234:Stem Cells / Q000378:metabolism
D019941:Cyclin-Dependent Kinase Inhibitor p16; D035683:MicroRNAs; C507096:Mmp14 protein, mouse; C541485:EGFR protein, mouse; D066246:ErbB Receptors; D053511:Matrix Metalloproteinase 14