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 investigate the role of hepatitis B virus X-protein(HBx)-induced reactive oxygen species(ROS)on liver carcinogenesis in HBx transgenic mice and HepG2-HBx cells.METHODS:Cell growth rate was analyzed,and through ...AIM:To investigate the role of hepatitis B virus X-protein(HBx)-induced reactive oxygen species(ROS)on liver carcinogenesis in HBx transgenic mice and HepG2-HBx cells.METHODS:Cell growth rate was analyzed,and through western blotting,mitogenic signaling was observed.Endogenous ROS from wild and HBx transgenic mice and HepG2-Mock and HBx cells were assayed by FACS-calibur.Identification of oxidized and reduced phosphatase and tensin homolog(PTEN)was analyzed through N-ethylmaleimide alkylation,nonreducing electrophoresis.RESULTS:We observed that the cell-proliferation-related phosphoinositide 3-kinase/Akt pathway is activated by HBx in vivo and in vitro.Increased ROS were detected by HBx.Tumor suppressor PTEN,via dephosphorylation of Akt,was oxidized and inactivated by increased ROS.Increased oxidized PTEN activated the mitogenic pathway through over-activated Akt.However,treatment with ROS scavenger N-acetyl cysteine can reverse PTEN to a reduced form.Endogenously produced ROS also stimulated HBx expression.CONCLUSION:HBx induced ROS promoted Akt pathways via oxidized inactive PTEN.HBx and ROS maintained a positive regulatory loop,which aggravated carcinogenesis.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 The 21st century Frontier Program in the Functional Human Genome Project,No.HGM0200934the International Collaboration Program of Science and Technology,No. FGM0600914+1 种基金the Research Program for New Drug Target Discovery Grant from the Ministry of Education,Science & Technology,No.NBM3300711the KRIBB Research Initiative Program Grant,No.KGM3320911
文摘AIM:To investigate the role of hepatitis B virus X-protein(HBx)-induced reactive oxygen species(ROS)on liver carcinogenesis in HBx transgenic mice and HepG2-HBx cells.METHODS:Cell growth rate was analyzed,and through western blotting,mitogenic signaling was observed.Endogenous ROS from wild and HBx transgenic mice and HepG2-Mock and HBx cells were assayed by FACS-calibur.Identification of oxidized and reduced phosphatase and tensin homolog(PTEN)was analyzed through N-ethylmaleimide alkylation,nonreducing electrophoresis.RESULTS:We observed that the cell-proliferation-related phosphoinositide 3-kinase/Akt pathway is activated by HBx in vivo and in vitro.Increased ROS were detected by HBx.Tumor suppressor PTEN,via dephosphorylation of Akt,was oxidized and inactivated by increased ROS.Increased oxidized PTEN activated the mitogenic pathway through over-activated Akt.However,treatment with ROS scavenger N-acetyl cysteine can reverse PTEN to a reduced form.Endogenously produced ROS also stimulated HBx expression.CONCLUSION:HBx induced ROS promoted Akt pathways via oxidized inactive PTEN.HBx and ROS maintained a positive regulatory loop,which aggravated carcinogenesis.
