bcl-2-specific siRNAs restore gemcitabine sensitivity in human pancreatic cancer cells.
Gemcitabine has been shown to ameliorate disease related symptoms and to prolong overall survival in pancreatic cancer.Yet, resistance to Gemcitabine is commonly observed in this tumour entity and has been linked to increased expression of anti-apoptotic bcl-2. We therefore investigated if and to what extend silencing of bcl-2 by specific siRNAs (siBCL2) might enhance Gemcitabine effects in human pancreatic carcinoma cells. siBCL2 was transfected into the pancreatic cancer cell line YAP C alone and 72 hrs before co-incubation with different concentrations of Gemcitabine. Total protein and RNA were extracted for Western-blot analysis and quantitative polymerase chain reaction. Pancreatic cancer xenografts in male nude mice were treated intraperitoneally with siBCL2 alone, Gemcitabine and control siRNA or Gemcitabine and siBCL2 for 21 days. Combination of both methods lead to a synergistic induction of apoptosis at otherwise ineffective concentrations of Gemcitabine. Tumour growth suppression was also potentiated by the combined treatment with siBCL2 and Gemcitabine in vivo and lead to increased TUNEL positivity. In contrast, non-transformed human foreskin fibroblasts showed only minor responses to this treatment. Our results demonstrate that siRNA-mediated silencing of anti-apoptotic bcl-2 enhances chemotherapy sensitivity in human pancreatic cancer cells in vitro and might lead to improved therapy responses in advanced stages of this disease.
Okamoto
Kinya
K
Department of Medicine 1, University Hospital Erlangen, Friedrich-Alexander-University Erlangen-Nuernberg, Ulmenweg 18, D-91054 Erlangen, Germany.
Ocker
Matthias
M
Neureiter
Daniel
D
Dietze
Otto
O
Zopf
Steffen
S
Hahn
Eckhart G
EG
Herold
Christoph
C
D000230:Adenocarcinoma / Q000473:pathology; D000964:Antimetabolites, Antineoplastic / Q000494:pharmacology*; D045744:Cell Line, Tumor; D003841:Deoxycytidine / Q000031:analogs & derivatives* / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D019254:Genes, bcl-2; D006801:Humans; D010190:Pancreatic Neoplasms / Q000235:genetics / Q000473:pathology / Q000628:therapy*; D034741:RNA, Small Interfering / Q000378:metabolism / Q000627:therapeutic use*; D013997:Time Factors; D014162:Transfection; D000093542:Gemcitabine
D000964:Antimetabolites, Antineoplastic; D034741:RNA, Small Interfering; D003841:Deoxycytidine; D000093542:Gemcitabine