Inhibition of MIF leads to cell cycle arrest and apoptosis in pancreatic cancer cells.
BACKGROUND
Pancreatic ductal adenocarcinoma (PDAC) is the eighth most common cancer with the lowest overall 5-y relative survival rate. Gene expression profiling of PDAC revealed an overexpression of the macrophage migration inhibitory factor (MIF), a lymphokine involved in cell-mediated immunity and inflammation, as well as in the regulation of cellular signal transduction.


METHODS
Endogenous MIF expression was silenced by treatment of pancreatic cancer cell lines using two independent MIF siRNAs. The expression of MIF RNA and protein after siRNA treatment was investigated using quantitative RT-PCR and Western blot. Induction of apoptosis was analyzed using fluorescence activated cell sorting (FACS).


RESULTS
Transfection of MiaPaCa-2 cells with MIF siRNA resulted in a reduction of MIF RNA and protein levels by more than 85%. After treatment, we observed an inhibition of cellular proliferation accompanied by induction of apoptosis. Analysis of the phosphorylation state of Akt showed a markedly increase of the phosphorylation at the Thr308 residue.


CONCLUSIONS
Using post-transcriptional silencing with small interfering RNAs, we could show that MIF acts as an autocrine growth factor involved in cell cycle progression. Since MIF is a secreted protein, a therapy directed against MIF or its receptor might lead to a significant growth reduction of PDAC.
Denz
Axel
A
Department of Visceral-, Thoracic-, and Vascular Surgery, University Hospital Carl Gustav Carus, Dresden, Germany. axel.denz@uniklinikum-dresden.de
Pilarsky
Christian
C
Muth
Daniela
D
Rückert
Felix
F
Saeger
Hans-Detlev
HD
Grützmann
Robert
R
D017209:Apoptosis; D021441:Carcinoma, Pancreatic Ductal / Q000378:metabolism*; D002453:Cell Cycle; D045744:Cell Line, Tumor; D049109:Cell Proliferation; D020869:Gene Expression Profiling; D020868:Gene Silencing; D006801:Humans; D019746:Intramolecular Oxidoreductases / Q000378:metabolism*; D008263:Macrophage Migration-Inhibitory Factors / Q000378:metabolism*; D010190:Pancreatic Neoplasms / Q000378:metabolism*; D010766:Phosphorylation; D051057:Proto-Oncogene Proteins c-akt / Q000378:metabolism; D034741:RNA, Small Interfering
D008263:Macrophage Migration-Inhibitory Factors; D034741:RNA, Small Interfering; D051057:Proto-Oncogene Proteins c-akt; D019746:Intramolecular Oxidoreductases; C515598:MIF protein, human