ObjectiveTo explore the influence mechanism of proliferation and invasion in colon cancer cell after silence of phosphatase and tensin homolog deleted on chromosome 10 (PTEN) gene. MethodsRT-PCR or Western blot method was used to detect the expression of PTEN mRNA or protein among four colon cancer cell lines (HT-29, WiDr, CaCo-2, and Colo320 cell lines). small interfering RNA (siRNA) was used to synthetize PTEN siRNA and transfect it into colon cancer cells. The expression of PTEN protein after transfecting was detected by Western blot. WsT-1 and invasion assay were used to examine the effects of PTEN siRNA silence on proliferation and invasion in colon cancer cells. ResultsPTEN mRNA and protein were expressed in all the four colon cancer cell lines. After PTEN siRNA transfected into the colon cancer cells, the expressions of PTEN proteins were inhibited in all the four colon cancer cell lines (P < 0.01), and the proliferation and invasion of colon cancer cells were enhanced significantly (P < 0.01). ConclusionsPTEN siRNA play an important role in metastasis process of colon cancer via enhanced its proliferation and invasion. Therefore, the understanding biologic mechanisms for regulation of PTEN might enable better molecular target therapy of treating the colon cancer patients with metastasis.
ObjectiveTo study effects of oxymatrine on proliferation and apoptosis of gastric cancer cell line BGC-823 and explore role of endoplasmic reticulum stress in apoptosis of gastric cancer cells induced by oxymatrine and elucidate its mechanism.MethodsThe gastric cancer BGC-823 cells at the logarithmic phase were divided into a control group, oxymatrine alone group (oxymatrine at 10, 30, 60 and 90 μmol/L concentrations), and combination group (oxymatrine at various concentrations combined with 2 μmol/L endoplasmic reticulum stress inhibitor salubrinal). The MTT assay was used to observe the inhibitory effect of the oxymatrine on the growth of BGC-823 cells. The flow cytometry was used to analyze the apoptosis and cell cycle. The Western blot and RT-PCR methods were used to detect the expressions of GRP78/Bip and the caspase-12 protein and gene, respectively.Results① Compared with the control group, the oxymatrine could significantly inhibit the growth of gastric cancer BGC-823 cells in a concentration-time dependent manner (P<0.05) and its IC50 (48 h) value was (59.5±0.5) μmol/L. The inhibitory effect of the combination group of 30, 60, and 90 μmol/L oxymatrine was significantly weakened as compared with the the corresponding oxymatrine alone group (P<0.05). ② The oxymatrine could significantly induce the apoptosis and arrest the G2/M phase in the gastric cancer BGC-823 cells in a concentration-dependent manner (P<0.05). The combination group of 60 μmol/L oxymatrine could significantly decreased the apoptosis rate and the number of cells in the G2/M phase in the gastric cancer BGC-823 cells after treating 48 h (P<0.05). ③ The protein and gene levels of GRP78/Bip and caspase-12 showed significant increases with the increase of oxymatrine concentrations in the oxymatrine alone group (except the protein and gene levels of caspase-12 at 10 μmol/L oxymatrine) as compared with the control group (P<0.05), which in the combination group of 60 μmol/L and 90 μmol/L oxymatrines were significantly decreased as compared with the corresponding oxymatrine alone group (P<0.05).ConclusionOxymatrine can inhibit growth of human gastric cancer cell line BGC-823, which maybe related to caspase-12-dependent induction of apoptosis and up-regulation of GRP78/Bip expression, which needs further experimental verification.