Gemcitabine-resistant Human Pancreatic Cancer Cell Line Overexpresses APE1/Ref-1 / 胃肠病学

ABSTRACT

Background:Gemcitabine is the main drug for chemotherapy of advanced pancreatic cancer,however,the prognosis of pancreatic cancer patients has not been changed obviously because of the high innate and acquired resistance of cancer cells to gemcitabine. Aims:To investigate the correlation of DNA repair and expression of human APE1 / Ref-1(apurinic/apyrimidinic endonuclease 1 / redox factor-1),the key enzyme in base excision repair pathway,with the resistance of pancreatic cancer to gemcitabine. Methods:A gemcitabine-resistant human pancreatic cancer cell line SW1990-0. 5 with a resistance index of 9. 32 and its parental cell line SW1990 were treated with gemcitabine. DNA injury was assessed by comet assay. Expressions of APE1 / Ref-1 mRNA and protein were determined by real-time PCR and Western blotting, respectively. Results:In comet assay,after treated with gemcitabine for 24 hours,OTM value of SW1990-0. 5 and SW1990 cells were 0. 32 ± 0. 13 and 26. 96 ± 6. 83,respectively. Expression level of APE1 / Ref-1 mRNA in SW1990-0. 5 cells was 2. 48 ± 0. 49;and expression levels of APE1 / Ref-1 protein in SW1990-0. 5 and SW1990 cells were 1. 57 ± 0. 08 and 0. 84 ± 0. 06,respectively. Statistically significant differences were existed in all these parameters between SW1990-0. 5 and SW1990 cells(P all < 0. 05). Conclusions:DNA repair might be correlated with the resistance of pancreatic cancer to gemcitabine,and up-regulation of APE1 / Ref-1 might contribute to this resistance by its function on DNA repair.