Jian Jie, Hu Zhi-Fang, Huang Yuan
Department of Gastroenterology, The Second Affiliated Hospital of Nanchang University, Jiangxi Provincial Key Laboratory of Molecular Medicine, Nanchang, Jiangxi, China.
Ai Zheng. 2009 May;28(5):461-5.
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.
PANC-1 cells were exposed to 10, 20, 40 and 80 micromol/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.
The inhibitory rates of 10, 20, 40 and 80 micromol/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 micromol/L) than in the control group (12.2% vs. 3.3%, P<0.05). 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)%,P<0.01;(20.8+/-2.6)% vs.(13.0+/-4.1)%,P<0.05], while the expressions of pim-3 and pBad (Ser112) were both decreased.
The anti-tumor effect of ginsenoside Rg3 may be associated with the decrease of Pim-3 and pBad (Ser112).
人参皂苷Rg3是一种具有抗癌作用的中药单体。本研究旨在探讨人参皂苷Rg3对人胰腺癌细胞系PANC-1中Pim-3和磷酸化Bad（pBad）蛋白、pBad（Ser112）和pBad（Ser136）的影响。
将PANC-1细胞分别用10、20、40和80 μmol/L人参皂苷Rg3处理24小时。克隆Pim-3的短发夹RNA（shRNA）并插入真核表达载体pSilencer 3.1-H1 Neo中构建pSilencer 3.1-H1 Neo-Pim-3。然后将pSilencer 3.1-H1 Neo-Pim-3转染到PANC-1细胞中。采用MTT法检测细胞增殖；在倒置显微镜下观察细胞凋亡情况，并通过Annexin V/PI染色的流式细胞术进行检测；采用蛋白质免疫印迹法检测Pim-3、Bad、pBad（Ser112）和pBad（Ser136）的蛋白表达。
10、20、40和80 μmol/L人参皂苷Rg3对PANC-1细胞的抑制率分别为20.2%、33.4%、52.8%和65.3%。人参皂苷Rg3诱导了典型的凋亡形态学变化。人参皂苷Rg3处理组（80 μmol/L）PANC-1细胞的凋亡率显著高于对照组（12.2%对3.3%，P<0.05）。人参皂苷Rg3对总Bad蛋白表达无影响，但以剂量依赖方式降低了Pim-3和pBad（Ser112）的表达。pBad（Ser136）在PANC-1细胞中未表达。与对照组相比，转染pim-3-shRNA的PANC-1细胞早期凋亡和总凋亡细胞百分比显著增加[（11.5±3.7）%对（5.8±2.2）%，P<0.01；（20.8±2.6）%对（13.0±4.1）%，P<0.05]，而pim-3和pBad（Ser112）的表达均降低。
人参皂苷Rg3的抗肿瘤作用可能与Pim-3和pBad（Ser112）的降低有关。
