Gemcitabine induces Notch signaling pathway activation in pancreatic cancer cell lines SW1990 and BxPC3

Abstract

Objective To investigate the changes of Notch signaling pathway activity in human pancreatic cancer cell lines (SW1990, BxPC3 )after gemcitabine induction, and to study its relationship with pancreatic cancer resistant to gemcitabine chemotherapy. Methods The pancreatic cancer cell lines SW1990 and BxPC3 were cultured with different concentrations of gemcitabine for 48 hours. The Notch signaling pathway receptors ( Notch1, Notch2, Notch3, Notch4), ligands (Jagged1, Jagged2) and downstream target Hesl mRNAs expression were detected by quantitative real-time PCR (Q-PCR). Protein levels of Hes1 were determined by Western blotting. Results After treatment with 2 μmol/L gemcitabine for 48 hours, the expression of Notch1, Notch2, Notch3, Jagged1, Jagged2 and Hes1 mRNAs in SW1990 cells were 8.26 ±0.48, 39.12 ±4.87, 0.84 ±0.06, 105.8 ± 17.92, 6.59 ±0.32 and 17.30 ±2.96, which were significantly elevated when compared with those without gemcitabine treatment ( 1.02 ± 0. 15, 15.25 ± 1.28, 0. 12 ± 0.02,32.66 ± 1.98, 1.88 ± 0.29 and 5.02 ± 0.64, P < 0.05 or P < 0. 01 ); the expression in BxPC3 cells was 7.87 ±0.59, 109.4 ± 10.98, 0.74 ±0.19, 62.73 ± 13.50, 2.09 ±0.16 and 15.38 ± 1.06, which were significantly elevated when compared with those without gemcitabine treatment ( 1.14 ±0.43, 58.96 ±2.63,0.10 ± 0.02, 16.95 ± 3.79, 0.98 ± 0.02 and 2.04 ± 0.16, P < 0.05 or P < 0.01 ). The expressions of Hes1protein in SW1990 cells after 1, 2 μmol/L gemcitabine treatment for 48 h were 0.30 ±0.03, 0.42 ±0.03;and the expressions in BxPC3 cells were 0.33 ± 0.02, 0.45 ± 0.03, which were significantly increased when compared with those without gemcitabine treatment (0.13 ± 0.01, F = 33.71,0.09 ± 0.02, F = 38.54, P <0.01 ). Conclusions The Notch signaling pathway is significantly activated in pancreatic cancer cells SW1990 and BxPC3 by gemcitabine, which may be one of the mechanisms of chemoresistance. Key words: Pancreatic neoplasms; Gemcitabine; Notch receptors; Signal transducing