AIM: To explore the regulatory mechanism of the target gene of micro RNA-21(mi R-21), phosphatase gene(p TEN), and its downstream proteins, protein kinase B(AKT) and phosphatidylinositol 3-kinase(p I3K), in colorectal...AIM: To explore the regulatory mechanism of the target gene of micro RNA-21(mi R-21), phosphatase gene(p TEN), and its downstream proteins, protein kinase B(AKT) and phosphatidylinositol 3-kinase(p I3K), in colorectal cancer(CRC) cells. METHODS: Quantitative real-time p CR(q RT-p CR) and Western blot were used to detect the expression levels of mi R-21 and p TEN in HCT116, HT29, Colo32 and SW480 CRC cell lines. Also, the expression levels of p TEN m RNA and its downstream proteins AKT and p I3 K in HCT116 cells after downregulating mi R-21 were investigated. RESULTS: Comparing the mi R-21 expression in CRC cells, the expression levels of mi R-21 were highest in HCT116 cells, and the expression levels of mi R-21 were lowest in SW480 cells. In comparing mi R-21 and p TEN expression in CRC cells, we found that the protein expression levels of mi R-21 and p TEN were inversely correlated(p < 0.05); when mi R-21 expression was reduced, m RNA expression levels of p TEN did not significantly change(p > 0.05), but the expression levels of its protein significantly increased(p < 0.05). In comparing the levels of p TEN protein and downstream AKT and p I3 K in HCT116 cells after downregulation of mi R-21 expression, the levels of AKT and p I3 K protein expression significantly decreased(p < 0.05). CONCLUSION: p TEN is one of the direct target genesof mi R-21. Thus, phosphatase gene and its downstream AKT and p I3 K expression levels can be regulated by regulating the expression levels of mi R-21, which in turn regulates the development of CRC.展开更多
AIM: To determine the expression of micro RNA-210(mi R-210) in hepatocellular carcinoma(HCC) and to examine its role using HCC cells.METHODS: The expression of mi R-210 was determined in 21 pairs of HCC samples and th...AIM: To determine the expression of micro RNA-210(mi R-210) in hepatocellular carcinoma(HCC) and to examine its role using HCC cells.METHODS: The expression of mi R-210 was determined in 21 pairs of HCC samples and the corresponding surrounding non-tumor tissues. The effects of mi R-210 on proliferation and cell cycle progression were examined using Hep G2 and Hu H7 cells. Overexpression and inhibition of mi R-210 was achieved by transfection of the cells with mi R-210 mimic or inhibitor. Luciferase reporter constructs were used to identify the mi R-210 interacting site on Yes1. Yes1 expression was examined after mi R-210 transfection,as well as in the HCC samples.RESULTS: mi R-210 was significantly up-regulated by 3.4 fold(P < 0.01) in the tumor samples. The over-expression of mi R-210 significantly reduced cell proliferation compared to the mock-treated cells(68.9% ± 7.4% and 53.6% ± 5.0%,P < 0.05 for the Hep G2 and Hu H7 cells respectively). Analysis of the Hu H7 cells transfected with mi R-210 mimic by flow cytometry showed that the cells took a longer time to reach the G2/M phase. The interaction between mi R-210 and the 3'UTR of the Yes1 transcript was confirmed using a luciferase reporter assay. Over-expression of mi R-210 reduced the expression of Yes1 protein in both Hu H7 and Hep G2 cells. Tumors with a greater than fourfold increase in the expression of mi R-210 showed consistently lower expressions of Yes1 in the tumors.In nocodazole-treated cells with a significant G2/M cell population,Yes1 protein was significantly reduced and pre-inhibition of mi R-210 in Hu H7 cells was able to prevent the reduction of Yes1 protein expression. Knock-down of Yes1 by si RNA also led to reduced cell proliferation(70.8% ± 7.5%,P < 0.05 in the Hu H7 cells).CONCLUSION: Up-regulation of mi R-210 inhibits cell proliferation. Yes1 is a target of mi R-210 and affects cell proliferation in HCC.展开更多
文摘AIM: To explore the regulatory mechanism of the target gene of micro RNA-21(mi R-21), phosphatase gene(p TEN), and its downstream proteins, protein kinase B(AKT) and phosphatidylinositol 3-kinase(p I3K), in colorectal cancer(CRC) cells. METHODS: Quantitative real-time p CR(q RT-p CR) and Western blot were used to detect the expression levels of mi R-21 and p TEN in HCT116, HT29, Colo32 and SW480 CRC cell lines. Also, the expression levels of p TEN m RNA and its downstream proteins AKT and p I3 K in HCT116 cells after downregulating mi R-21 were investigated. RESULTS: Comparing the mi R-21 expression in CRC cells, the expression levels of mi R-21 were highest in HCT116 cells, and the expression levels of mi R-21 were lowest in SW480 cells. In comparing mi R-21 and p TEN expression in CRC cells, we found that the protein expression levels of mi R-21 and p TEN were inversely correlated(p < 0.05); when mi R-21 expression was reduced, m RNA expression levels of p TEN did not significantly change(p > 0.05), but the expression levels of its protein significantly increased(p < 0.05). In comparing the levels of p TEN protein and downstream AKT and p I3 K in HCT116 cells after downregulation of mi R-21 expression, the levels of AKT and p I3 K protein expression significantly decreased(p < 0.05). CONCLUSION: p TEN is one of the direct target genesof mi R-21. Thus, phosphatase gene and its downstream AKT and p I3 K expression levels can be regulated by regulating the expression levels of mi R-21, which in turn regulates the development of CRC.
基金Supported by Biomedical Research Council and Ministry of Education(Tier 1)awarded to Tan TM
文摘AIM: To determine the expression of micro RNA-210(mi R-210) in hepatocellular carcinoma(HCC) and to examine its role using HCC cells.METHODS: The expression of mi R-210 was determined in 21 pairs of HCC samples and the corresponding surrounding non-tumor tissues. The effects of mi R-210 on proliferation and cell cycle progression were examined using Hep G2 and Hu H7 cells. Overexpression and inhibition of mi R-210 was achieved by transfection of the cells with mi R-210 mimic or inhibitor. Luciferase reporter constructs were used to identify the mi R-210 interacting site on Yes1. Yes1 expression was examined after mi R-210 transfection,as well as in the HCC samples.RESULTS: mi R-210 was significantly up-regulated by 3.4 fold(P < 0.01) in the tumor samples. The over-expression of mi R-210 significantly reduced cell proliferation compared to the mock-treated cells(68.9% ± 7.4% and 53.6% ± 5.0%,P < 0.05 for the Hep G2 and Hu H7 cells respectively). Analysis of the Hu H7 cells transfected with mi R-210 mimic by flow cytometry showed that the cells took a longer time to reach the G2/M phase. The interaction between mi R-210 and the 3'UTR of the Yes1 transcript was confirmed using a luciferase reporter assay. Over-expression of mi R-210 reduced the expression of Yes1 protein in both Hu H7 and Hep G2 cells. Tumors with a greater than fourfold increase in the expression of mi R-210 showed consistently lower expressions of Yes1 in the tumors.In nocodazole-treated cells with a significant G2/M cell population,Yes1 protein was significantly reduced and pre-inhibition of mi R-210 in Hu H7 cells was able to prevent the reduction of Yes1 protein expression. Knock-down of Yes1 by si RNA also led to reduced cell proliferation(70.8% ± 7.5%,P < 0.05 in the Hu H7 cells).CONCLUSION: Up-regulation of mi R-210 inhibits cell proliferation. Yes1 is a target of mi R-210 and affects cell proliferation in HCC.
