Effect of valproic acid on the proliferation of human pancreatic cancer cell PaTu8988 and dose-effect relationship

Objective To investigate the effects of valproic acid ( VPA) on cell proliferation and cell cycle in human pancreatic cancer cell line PaTu8988 in vitro. Methods PaTu8988 cells were treated with VPA in concentration of 0, 0.2, 1.0 or 5.0 mmol/L for 24 h and 48 h respectively. Cell viability was measured by WST-8 assay. Cell cycles were detected by flow cytometery. Dimethyl sulfoxide added to the medium was used as blank control group, while PBS added to the medium was used as PBS group. Results After VPA treatment for 24 h, the inhibition rate of VPA 5.0 mmol/L group was 18.9% , which was significantly higher than those in control group, PBS group and VPA 0.2, 1.0 mmol/L group (0, 4.4% , 6.8%, 6.1% , P <0.05). After 48 h, the inhibition rates of VPA 1.0, 5.0 mmol/L were 12.9%, 25.9% , which was significantly higher than those in control group, PBS group and VPA 0.2 mmol/L group (0, 6.2% , 4.6% , P <0.01). After VPA treatment for 24 h, the proportions of G2 phase cell in VPA 1.0, 5.0 mmol/L group were ( 26.57 ± 1.88) % , ( 34.11 ± 4.74 ) % , which was significantly higher than those in PBS group, control group, VPA 0.2 mmol/L group [(10.72 ± 2.02)% , ( 13.53 ± 2.28)% , (13.81 ±2.40)%, P <0.01 ], the changes 48 h after VPA treatment was consistent with the changes 24 h after VPA treatment. Conclusions VPA may significantly suppress the cell proliferation of human pancreatic cancer cell line PaTu8988, and induce cell cycle arrest in G2 phase in a time and dose-dependent manner. Key words: Pancreatic neoplasm;  Valproic acid;  Acetylation;  Cell proliferation;  Cell cycle