The expression of phosphatase and tensin homolog (PTEN ), a tumor suppressor gene, is frequently downregulated in gastric carcinomas due to mutation, loss of heterozygosity, and promoter hypermethylation. However, it ...The expression of phosphatase and tensin homolog (PTEN ), a tumor suppressor gene, is frequently downregulated in gastric carcinomas due to mutation, loss of heterozygosity, and promoter hypermethylation. However, it is unknown if additional mechanisms may account for the down-regulation of PTEN expression. While neuronal precursor cell-expressed developmentally down-regulated 4-1 (NEDD4-1) is believed to be a potential dual regulator of PTEN, there are conflicting reports regarding their interaction. To gain further insight into the role of NEDD4-1 and its association with PTEN in gastric carcinoma development, we measured the protein expression of NEDD4-1 and PTEN in gastric mucosae with various pathological lesions and found that NEDD4-1 increased from normal gastric mucosa to intestinal metaplasia and decreased from dysplasia to gastric carcinoma. These changes did not correlate with PTEN expression changes during gastric carcinogenesis. Moreover, we found similar results in protein levels in the primary tumors and adjacent non-tumorous tissues. These results differ from a previous report showing that expression of NEDD4-1 is up-regulated in gastric carcinomas, and show a more complex pattern of NEDD4-1 gene expression during gastric carcinogenesis.展开更多
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
To examine phosphatase and tensin homology deleted in chromosome 10 (PTEN),hypoxia-inducible factor-1 alpha (HIF-1 alpha) gene expressions and their relation to vascular endothelial growth factor(VEGF) protein express...To examine phosphatase and tensin homology deleted in chromosome 10 (PTEN),hypoxia-inducible factor-1 alpha (HIF-1 alpha) gene expressions and their relation to vascular endothelial growth factor(VEGF) protein expression in the patients with human colorectal adenomas and adenocarcinomas.Methods The expression of PTEN,HIF-1 alpha gene was detected by using in situ hybridization,and the VEGF expression levels by immunohistochemistry in colorectal adenomas and primary colorectal adenocarcinoma.Results Strong expression of HIF-1 alpha was detectable in the majority of colorectal dadenocarcinoma,particularly surrounding areas of necrosis in adenocarcinoma.PTEN,HIF-1 alpha mRNA and VEGF protein were positive in 51.6%,67.7% and 59.7% respectively in 62 cases of adenocarcinomas,and 77.8%,44.4% and 33.3% respectively in 18 cases of adenomas.The positive rate of VEGF was higher in the patients with colorectal adenocarcinomas than that in those with adenomas,whereas that of PTEN mRNA was contrary.HIF-1 mRNA expression was correlated significantly with lymph node metastasis,liver metastasis,Duke’s stage and recurrence.During colorectal tumor progression,the expression of HIF-1 alpha mRNA was positively correlated with the VEGF protein expression (χ2= 4.751 ,P<0.05),but negatively with the PTEN mRNA expression(χ2=21.84,P<0.01).Conclusion The absence or low expression of PTEN and the increased levels of HIF-1α and VEGF may paly an important role in carcinogenesis and progression of colorectal carcinoma.These results suggest that VEGF upregulated by HIF-1 alpha gene may be involved in angiogenesis of colorectal adenocarcinoma.4 refs,1 tab.展开更多
Background:Studies have reported mitophagy activation in renal tubular epithelial cells(RTECs)in acute kidney injury(AKI).Phosphatase and tensin homolog-induced putative kinase 1(PINK1)and E3 ubiquitin-protein ligase ...Background:Studies have reported mitophagy activation in renal tubular epithelial cells(RTECs)in acute kidney injury(AKI).Phosphatase and tensin homolog-induced putative kinase 1(PINK1)and E3 ubiquitin-protein ligase Parkin are involved in mitophagy regulation;however,little is known about the role of PINK1-Parkin mitophagy in septic AKI.Here we investigated whether the PINK1-Parkin mitophagy pathway is involved in septic AKI and its effects on cell apoptosis in vitro and on renal functions in vivo.Methods:Mitophagy-related gene expression was determined using Western blot assay in human RTEC cell line HK-2 stimulated with bacterial lipopolysaccharide(LPS)and in RTECs from septic AKI rats induced by cecal ligation and perforation(CLP).Autophagy-related ultrastructural features in rat RTECs were observed using electron microscopy.Gain-and loss-of-function approaches were performed to investigate the role of the PINK1-Parkin pathway in HK-2 cell mitophagy.Autophagy activators and inhibitors were used to assess the effects of mitophagy modulation on cell apoptosis in vitro and on renal functions in vivo.Results:LPS stimulation could significantly induce LC3-II and BECN-1 protein expression(LC3-II:1.72±0.05 vs.1.00±0.05,P<0.05;BECN-1:5.33±0.57 vs.1.00±0.14,P<0.05)at 4 h in vitro.Similarly,LC3-II,and BECN-1 protein levels were significantly increased and peaked at 2 h after CLP(LC3-II:3.33±0.12 vs.1.03±0.15,P<0.05;BECN-1:1.57±0.26 vs.1.02±0.11,P<0.05)in vivo compared with those after sham operation.Mitochondrial deformation and mitolysosome-mediated mitochondria clearance were observed in RTECs from septic rats.PINK1 knockdown significantly attenuated LC3-II protein expression(1.35±0.21 vs.2.38±0.22,P<0.05),whereas PINK1 overexpression markedly enhanced LC3-II protein expression(2.07±0.21 vs.1.29±0.19,P<0.05)compared with LPS-stimulated HK-2 cells.LPS-induced proapoptotic protein expression remained unchanged in autophagy activator-treated HK-2 cells and was significantly attenuated in PINK1-overexpressing cells,but was remarkably upregulated in autophagy inhibitor-treated and in PINK1-depleted cells.Consistent results were observed in flow cytometric apoptosis assay and in renal function indicators in rats.Conclusion:PINK1-Parkin-mediated mitophagy might play a protective role in septic AKI,serving as a potential therapeutic target for septic AKI.展开更多
基金Supported by Grants from the National Natural Science Foundation of China, No. 81060038the Graduate Innovative Fund of Jiangxi Province, No. YC10A020
文摘The expression of phosphatase and tensin homolog (PTEN ), a tumor suppressor gene, is frequently downregulated in gastric carcinomas due to mutation, loss of heterozygosity, and promoter hypermethylation. However, it is unknown if additional mechanisms may account for the down-regulation of PTEN expression. While neuronal precursor cell-expressed developmentally down-regulated 4-1 (NEDD4-1) is believed to be a potential dual regulator of PTEN, there are conflicting reports regarding their interaction. To gain further insight into the role of NEDD4-1 and its association with PTEN in gastric carcinoma development, we measured the protein expression of NEDD4-1 and PTEN in gastric mucosae with various pathological lesions and found that NEDD4-1 increased from normal gastric mucosa to intestinal metaplasia and decreased from dysplasia to gastric carcinoma. These changes did not correlate with PTEN expression changes during gastric carcinogenesis. Moreover, we found similar results in protein levels in the primary tumors and adjacent non-tumorous tissues. These results differ from a previous report showing that expression of NEDD4-1 is up-regulated in gastric carcinomas, and show a more complex pattern of NEDD4-1 gene expression during gastric carcinogenesis.
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.
文摘To examine phosphatase and tensin homology deleted in chromosome 10 (PTEN),hypoxia-inducible factor-1 alpha (HIF-1 alpha) gene expressions and their relation to vascular endothelial growth factor(VEGF) protein expression in the patients with human colorectal adenomas and adenocarcinomas.Methods The expression of PTEN,HIF-1 alpha gene was detected by using in situ hybridization,and the VEGF expression levels by immunohistochemistry in colorectal adenomas and primary colorectal adenocarcinoma.Results Strong expression of HIF-1 alpha was detectable in the majority of colorectal dadenocarcinoma,particularly surrounding areas of necrosis in adenocarcinoma.PTEN,HIF-1 alpha mRNA and VEGF protein were positive in 51.6%,67.7% and 59.7% respectively in 62 cases of adenocarcinomas,and 77.8%,44.4% and 33.3% respectively in 18 cases of adenomas.The positive rate of VEGF was higher in the patients with colorectal adenocarcinomas than that in those with adenomas,whereas that of PTEN mRNA was contrary.HIF-1 mRNA expression was correlated significantly with lymph node metastasis,liver metastasis,Duke’s stage and recurrence.During colorectal tumor progression,the expression of HIF-1 alpha mRNA was positively correlated with the VEGF protein expression (χ2= 4.751 ,P<0.05),but negatively with the PTEN mRNA expression(χ2=21.84,P<0.01).Conclusion The absence or low expression of PTEN and the increased levels of HIF-1α and VEGF may paly an important role in carcinogenesis and progression of colorectal carcinoma.These results suggest that VEGF upregulated by HIF-1 alpha gene may be involved in angiogenesis of colorectal adenocarcinoma.4 refs,1 tab.
基金This work was supported by grants from the National Natural Science Foundation of China(Nos.81601708,81671960)the Natural Science Foundation of Hunan Province,China(No.2018JJ2014).
文摘Background:Studies have reported mitophagy activation in renal tubular epithelial cells(RTECs)in acute kidney injury(AKI).Phosphatase and tensin homolog-induced putative kinase 1(PINK1)and E3 ubiquitin-protein ligase Parkin are involved in mitophagy regulation;however,little is known about the role of PINK1-Parkin mitophagy in septic AKI.Here we investigated whether the PINK1-Parkin mitophagy pathway is involved in septic AKI and its effects on cell apoptosis in vitro and on renal functions in vivo.Methods:Mitophagy-related gene expression was determined using Western blot assay in human RTEC cell line HK-2 stimulated with bacterial lipopolysaccharide(LPS)and in RTECs from septic AKI rats induced by cecal ligation and perforation(CLP).Autophagy-related ultrastructural features in rat RTECs were observed using electron microscopy.Gain-and loss-of-function approaches were performed to investigate the role of the PINK1-Parkin pathway in HK-2 cell mitophagy.Autophagy activators and inhibitors were used to assess the effects of mitophagy modulation on cell apoptosis in vitro and on renal functions in vivo.Results:LPS stimulation could significantly induce LC3-II and BECN-1 protein expression(LC3-II:1.72±0.05 vs.1.00±0.05,P<0.05;BECN-1:5.33±0.57 vs.1.00±0.14,P<0.05)at 4 h in vitro.Similarly,LC3-II,and BECN-1 protein levels were significantly increased and peaked at 2 h after CLP(LC3-II:3.33±0.12 vs.1.03±0.15,P<0.05;BECN-1:1.57±0.26 vs.1.02±0.11,P<0.05)in vivo compared with those after sham operation.Mitochondrial deformation and mitolysosome-mediated mitochondria clearance were observed in RTECs from septic rats.PINK1 knockdown significantly attenuated LC3-II protein expression(1.35±0.21 vs.2.38±0.22,P<0.05),whereas PINK1 overexpression markedly enhanced LC3-II protein expression(2.07±0.21 vs.1.29±0.19,P<0.05)compared with LPS-stimulated HK-2 cells.LPS-induced proapoptotic protein expression remained unchanged in autophagy activator-treated HK-2 cells and was significantly attenuated in PINK1-overexpressing cells,but was remarkably upregulated in autophagy inhibitor-treated and in PINK1-depleted cells.Consistent results were observed in flow cytometric apoptosis assay and in renal function indicators in rats.Conclusion:PINK1-Parkin-mediated mitophagy might play a protective role in septic AKI,serving as a potential therapeutic target for septic AKI.
