Simultaneous gene silencing of Bcl-2, XIAP and Survivin re-sensitizes pancreatic cancer cells towards apoptosis.
BACKGROUND
Pancreatic ductal adenocarcinoma shows a distinct apoptosis resistance, which contributes significantly to the aggressive nature of this tumor and constrains the effectiveness of new therapeutic strategies. Apoptosis resistance is determined by the net balance of the cells pro-and anti-apoptotic "control mechanisms". Numerous dysregulated anti-apoptotic genes have been identified in pancreatic cancer and seem to contribute to the high anti-apoptotic buffering capacity. We aimed to compare the benefit of simultaneous gene silencing (SGS) of several candidate genes with conventional gene silencing of single genes.


METHODS
From literature search we identified the anti-apoptotic genes XIAP, Survivin and Bcl-2 as commonly upregulated in pancreatic cancer. We performed SGS and silencing of single candidate genes using siRNA molecules in two pancreatic cancer cell lines. Effectiveness of SGS was assessed by qRT-PCR and western blotting. Apoptosis induction was measured by flow cytometry and caspase activation.


RESULTS
Simultaneous gene silencing reduced expression of the three target genes effectively. Compared to silencing of a single target or control, SGS of these genes resulted in a significant higher induction of apoptosis in pancreatic cancer cells.


CONCLUSIONS
In the present study we performed a subliminal silencing of different anti-apoptotic target genes simultaneously. Compared to silencing of single target genes, SGS had a significant higher impact on apoptosis induction in pancreatic cancer cells. Thereby, we give further evidence for the concept of an anti-apoptotic buffering capacity of pancreatic cancer cells.
Rückert
Felix
F
Department of Visceral, Thoracic and Vascular Surgery, University Hospital Carl Gustav Carus, Technische Universität Dresden, Fetscherstrasse 47, 01307 Dresden, Germany. Felix.Rueckert@uniklinikum-dresden.de
Samm
Nicole
N
Lehner
Anne-Kathrin
AK
Saeger
Hans-Detlev
HD
Grützmann
Robert
R
Pilarsky
Christian
C
D017209:Apoptosis; D015153:Blotting, Western; D021441:Carcinoma, Pancreatic Ductal / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D020169:Caspases / Q000378:metabolism; D004789:Enzyme Activation; D005434:Flow Cytometry; D020868:Gene Silencing; D006801:Humans; D051034:Inhibitor of Apoptosis Proteins; D008869:Microtubule-Associated Proteins / Q000037:antagonists & inhibitors / Q000235:genetics* / Q000378:metabolism; D010190:Pancreatic Neoplasms / Q000235:genetics* / Q000378:metabolism / Q000473:pathology*; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000037:antagonists & inhibitors / Q000235:genetics* / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics; D034741:RNA, Small Interfering / Q000494:pharmacology; D020133:Reverse Transcriptase Polymerase Chain Reaction; D000077022:Survivin; D014407:Tumor Cells, Cultured; D051636:X-Linked Inhibitor of Apoptosis Protein / Q000037:antagonists & inhibitors / Q000235:genetics* / Q000378:metabolism
C107489:BIRC5 protein, human; D051034:Inhibitor of Apoptosis Proteins; D008869:Microtubule-Associated Proteins; D019253:Proto-Oncogene Proteins c-bcl-2; D012333:RNA, Messenger; D034741:RNA, Small Interfering; D000077022:Survivin; D051636:X-Linked Inhibitor of Apoptosis Protein; C496866:XIAP protein, human; D020169:Caspases