Growth-inhibition by TGF-β1 in BxPC-3 pancreatic carcinoma cell line and the primary mechanisms

Objective To observe the growth-inhibitory effect of TGF-β1 in BxPC-3 pancreatic carcinoma cell line and demonstrate its primary mechanisms involved.Methods To observe the dose-dependant manner,BxPC-3 pancreatic carcinoma cells were inoculated into the 96-well-plates.They were treated with 0,1.0,2.0,4.0,6.0 and 8.0 mg/L TGF-β1 respectively.MTT assay were performed after 4 days and the growth-inhibition rates were measured compared to the 0mg/L group as control.To observe the time-dependant manner,BxPC-3 cells were incubated with 2.0 mg/L TGF-β1 from 24 hours to 7 days,while the BxPC-3 cells without TGF-β1 incubation were considered as control.The growth curves were drawn in both groups with MTT assay.Meanwhile,cell cycle distribution was determined by flow cytometry after PI staining and Cyclin D1 expression was measured by Western blot assay in both control group and 2.0 mg/L TGF-β1 incubation group on the 4th day.Results Compared with controls,BxPC-3 cells with 2 ng/mL TGF-β1 incubation for seven days caused a mild growth inhibition,and the maximal inhibitory rate was 12.5%,which was discovered on the 4th day.FCM analysis showed G1/S arrest of the cell cycle in TGF-β1-treated cells,while the CyclinD1 protein was also down-regulated significantly.Conclusions Although smad4 is depleted in BxPC-3 cells,exogenous TGF-β1 can still produce a mild growth inhibition in BxPC-3 pancreatic carcinoma cells,possibly through G1/S cell cycle arrest and Cyclin D1 down-regulation.