Effect of erythropoietin on chemo-sensitivity of pancreatic cancer cell line SW1990 to gemcitabine

Objective To investigate the effect of erythropoietin (Epo) on cellular proliferation and chemo-sensitivity to gemcitabine of pancreatic cancer cell line SW1990,and to explore the possible mechanisms.Methods The expression of EpoR in SW1990 was detected by immunocytochemical method,cancer cell line SW1990 was interfered by different concentrations of Epo,the cellular proliferation and chemosensitivity to gemcitabine of SW1990 was detected by MTT method,the expression of MDR-1 mRNA,RRM1 mRNA was detected by RT-PCR.Results EpoR was expressed in SW1990.The average A630 were 0.597±0.043,0.645±0.073,0.690±0.094,0.630±0.073 in 0,2,4,10 U/ml Epo groups,respectively,but the difference didn't reach statistical significance.The average inhibitory rate (IR) in Epo treatment groups were (64.7±0.142)%,(35.6±0.076)%,(33.1±0.140)%,(29.9±0.082)%,MDR-1 mRNA expressions were 0.42±0.10,0.58±0.08,0.60±0.04,0.68±0.13;RRM1 mRNA expressions were 1.32 ±0.17,1.64±0.15,1.57±0.11,1.67±0.18.The Irs of SW1990 in 2,4,10 U/ml Epo groups were statistically lower than 0 U/ml Epo group,while the expressions of MDR-1 mRNA,RRM1 mRNA were significantly increased (P<0.01 or<0.05).The IR of gemcitabine on SW1990 was negatively related with the expressions of MDR-1 mRNA,RRM1 mRNA (r =-0.964,P=0.036;r=-0.968,P=0.032).Conclusions Epo might decrease the chemo-sensitivity of SW1990 to gemcitabine possibly by up-regulating the expressions of MDR-1 and RRM1. Key words: Pancreatic neoplasms; Erythropoietin; C; emeitabine; MDR genes; Ribonucleotide reductase subunit M1