Effect of ginsenoside Rg3 on Pim-3 and Bad proteins in human pancreatic cancer cell line PANC-1
Jie Jian, Zhi-Fang Hu and Yuan HuangDepartment of Gastroenterology, The Second Affiliated Hospital of Nanchang University, Jiangxi Provincial Key Laboratory of Molecular Medicine, Nanchang, Jiangxi, 330006, P. R. China
Background and Objective: Ginsenoside Rg3 is a traditional Chinese medicine monomer which possesses anticancer effects. This study was to investigate the effects of ginsenoside Rg3 on Pim-3 and phosphorylated Bad (pBad) proteins, pBad (Ser112) and pBad (Ser136) in human pancreatic cancer cell line PANC-1. Methods: PANC-1 cells were exposed to 10, 20, 40 and 80 μmol / L ginsenoside Rg3 for 24 h. A short hairpin RNA (shRNA) of Pim-3 was cloned and inserted into a eukaryotic expression vector pSilencer 3.1-H1 Neo to construct pSilencer 3.1-H1 Neo- Pim-3. pSilencer 3.1-H1 Neo-Pim-3 was then transfected into PANC-1 cells. Cell proliferation was measured by MTT assay; cell apoptosis was observed under an invert microscope and measured by flow cytometry with Annexin V / PI staining; protein expressions of Pim-3, Bad, pBad (Ser112) and pBad (Ser136) were measured by Western blot. Results: The inhibitory rates of 10, 20, 40 and 80 μmol/L ginsenoside Rg3 on PANC-1 cells were 20.2%, 33.4%, 52.8% and 65.3%, respectively. Typical morphological changes in apoptosis were induced by ginsenoside Rg3. The apoptotic rate of PANC-1 cells was significantly higher in the ginsenoside Rg3 treatment group (80 μmol / L) than in the control group (12.2% vs. 3.3%, P0.05). Ginsenoside Rg3 had no influence on the total Bad protein expression, but decreased both Pim-3 and pBad (Ser112) expressions in a dose-dependent manner. pBad (Ser136) was not expressed in PANC-1 cells. Compared with the control group, the percentages of early and total apoptotic cells were significantly increased in PANC-1 cells transfected with pim-3-shRNA [(11.5±3.7)% vs. (5.8±2.2)%, P0.01;(20.8±2.6)% vs.(13.0±4.1)%,P0.05], while the expressions of pim-3 and pBad (Ser112) were both decreased. Conclusion: The anti- tumor effect of ginsenoside Rg3 may be associated with the decrease of Pim- 3 and pBad (Ser112).