Effect of cerulenin combined with gemcitabine on proliferation and apoptosis in human pancreatic cell line BxPC3

Objective To investigate the effect and mechanism of action in pancreatic cancer BxPC3 cell treated by cerulenin in combination with gemcitabine.Methods BxPC3 cells were cultivated with 10 μg/ml cerulenin,20 μmol/L gemcitabine or 10 μg/ml cerulenin + 20 μmol/L gemcitabine for 48 h,and cells without treatment were control.Cell proliferation was detected by CCK-8 assay,and early apoptosis was detected by AnnexinV/PI double staining method.The expression of Bcl-2 mRNA and Bax mRNA were detected by RT-PCR,and the protein level of Bcl-2,Bax were detected by Western Blot.Results The inhibition rate of BxPC3 cells were 0,(51.28 ± 1.84) ％,(53.59 ± 1.62) ％,(84.57 ± 1.01) ％ in control,cerulenin group,gemcitabine group,combination group; and the rate of early apoptosis was (0.83 ± 0.31) ％,(31.37 ± 1.04) ％,(38.33 ± 0.75) ％,(69.43 ± 0.83) ％,and the expression of Bcl-2 mRNA was 0.67 ± 0.01,0.44 ±0.01,0.36 ±0.08,0.27 ±0.07,and the expression of Bax mRNA was 0.14 ±0.01,0.31 ± 0.02,0.32 ± 0.03,0.91 ± 0.06 ; while the ratio of Bcl-2 mRNA/Bax mRNA was 4.78 ± 0.13,1.39 ± 0.04,1.15 ± 0.02,0.30 ± 0.02 ; the expression of Bcl-2 protein was 1.24 ± 0.04,0.51 ± 0.02,0.42 ± 0.02,0.13 ±0.01 ; and the expression of Bax protein was 0.20 ± 0.05,0.47 ± 0.01,0.54 ± 0.01,1.21 ± 0.03 ; while the ratio of Bcl-2/Bax was 6.00 ± 0.11,1.11 ± 0.01,0.77 ± 0.03,0.10 ± 0.06.And the difference among the groups was statistically significant (P ＜ 0.01).Conclusions Cerulenin combined with gemcitabin has synergistic effect on the inhibition of BxPC cells proliferation.Its mechanisms may be up-regulation of Bax,down-regulation of Bcl-2,and promoting apoptosis of cells through the decrease of Bcl-2/Bax ratio. Key words: Pancreatic neoplasms;  Cerulenin;  Gemcitabine;  Drug synergism;  Apoptosis