PubMed | Beijing Institute of Radiation Medicine, Chinese National Institute for Radiological Protection, Hebei Institute of Gastroenterology and Hebei Medical University
Type: Journal Article | Journal: Cancer gene therapy | Year: 2016
Radiotherapy is one of the important treatments for patients with hepatocellular carcinoma. The treatment response (or efficacy), however, is limited in many patients due to acquired radiation resistance of cancer cells. Immediate-early response 5 (IER5) is one of the genes upregulated on radiation. The gene could modulate cell cycle checkpoint, leading to a decrease of cancer cell survival in response to radiation. To better understand how IRE5 expression is regulated on radiation, this study aims to identify transcription factors that interact with IER5 promoter region in liver cancer cell line. Using bioinformatic tool, we identified promoter region of IER5 gene. Subsequent luciferase reporter assay revealed two putative GC binding factor (GCF) binding sites. We found mutations of these binding sites increased the luciferase activity, suggesting a negative regulation of GCF on IER5 transcriptional activity. The physical interaction of GCF with the gene promoter was confirmed using chromatin immunoprecipitation and electrophoretic mobility shift assay assays. Different doses of radiation were also applied in these experiments, and we found the formation of protein-DNA complex reduced with the increasing dose of radiation. Together, we propose the GCF regulated transcriptional activity, at least in part, contributed to the upregulation of IER5 on radiation. The present findings provide insights into understanding the regulatory mechanisms of IER5.
Yang C.,Hebei Medical University |
Yang C.,Hebei Institute of Gastroenterology |
Wang Y.,Hebei Medical University |
Wang Y.,Hebei Institute of Gastroenterology |
And 14 more authors.
American Journal of Translational Research | Year: 2016
Purpose: To elucidate the mechanisms of the immediate-early response gene 5 (IER5) effect on the apoptosis induced by irradiation and cisplatin (CDDP) in human hepatocellular carcinoma (HepG2) cells. Methods: We generated IER5 overexpression stable cells (HepG2/IER5) using Lipofectamine 2000 transfection HepG2 cells. Cell apoptosis was induced by irradiation and cisplatin treatments, and cell proliferation (viability) and apoptosis were evaluated by MTT and flow cytometry assays. Protein expression was determined by Western blot. Results: The growth of the IER5 overexpression cells was significantly inhibited after six days of 60Co γ-irradiation exposure (p<0.01) compared with the cell growth of vector control cells. Furthermore, the HepG2/IER5 cells were arrested at the G2/M phases. We also found that the expression of phospho-Akt was reduced, and the levels of cleaved caspase-3 and PARP were increased after the treatment of HepG2/IER5 cells with γ-irradiation and cisplatin. Conclusion: Our results suggest that the overexpression of IER5 can inhibit cell growth and enhance the cell apoptosis induced by exposure to radiation or cisplatin. The overexpression of IER5 can be utilized as a targeting strategy to improve the outcomes of radiotherapy used for the treatment of patients with liver cancer. © 2016, E-Century Publishing Corporation. All rights reserved.
Wang N.,Hebei Institute of Gastroenterology |
Wang G.,Baoding Childrens Hospital |
Hao J.,Hebei Institute of Gastroenterology |
Ma J.,Hebei Institute of Gastroenterology |
And 3 more authors.
Digestive Diseases and Sciences | Year: 2012
Background: Disruption of epithelial tight junctions (TJ) followed by loss of barrier function is of crucial importance in the pathogenesis of a variety of gastrointestinal disorders. Heme oxygenase-1 (HO-1), which can be induced by curcumin (Cur), provides protection against various forms of oxidative stress. Aims: The protective effect of Cur on oxidative stressinduced intestinal barrier disruption in human intestinal epithelial cells was elucidated in this study. Methods: H 2O 2-induced Caco-2 enterocytic monolayers were incubated in the presence or absence of Cur and/or zinc protoporphyrin (ZnPP). The trans-epithelial electrical resistance (TEER) and the flux of sodium fluorescein in the filtergrown Caco-2 cell monolayers were measured. The expression and localization of the TJ protein occludin and zonula occluden-1 (ZO-1) were evaluated by western blot and immunofluorescence microscopy. The mRNA and protein levels of HO-1 were analyzed by real-time PCR and western blot. Results: Cur attenuated H 2O 2-induced disruption of paracellular permeability (TEER 52.02 ± 10.15% vs 22.71 ± 3.11%; sodium fluorescein flux 12.41 ± 2.19% vs 32.00 ± 4.97%, P < 0.05) and induced HO-1 mRNA (6.64 ± 0.48 vs 3.22 ± 0.28, P < 0.05) and protein (291.00 ± 9.17% vs 99.00 ± 10.00%, P < 0.05) expression in Caco-2 cells. After administration of H2O2, occludin and ZO-1 proteins were restored by Cur (occludin 175.67 ± 29.50% vs 53.67 ± 24.19%, P < 0.05; ZO-1 139.67 ± 33.71% vs 36.00 ± 15.88%, P < 0.05) and this effect was blocked by HO-1 inhibitor, ZnPP (occludin 54.67 ± 10.02% vs 168.33 ± 36.47%, P < 0.05; ZO-1 50.00 ± 15.13% vs 117.67 ± 38.81%, P < 0.05). Conclusion: Cur protects human intestinal epithelial cells against H 2O 2-induced disruption of TJ and barrier dysfunction via the HO-1 pathway. © Springer Science+Business Media, LLC 2012.
Zhao L.-M.,Hebei Medical University |
Zhao L.-M.,Hebei Institute of Gastroenterology |
Feng Z.-J.,Hebei Medical University |
Feng Z.-J.,Hebei Institute of Gastroenterology |
And 4 more authors.
World Chinese Journal of Digestology | Year: 2010
AIM: To explore the inhibitory effect of α-lipoic acid (ALA) on hepatic injury in rats with acute pancreatitis (AP). METHODS: A rat model of AP was established by retrograde injection of 3.5% sodium taurocholate into the biliopancreatic duct. Fifty-four Wistar rats (n = 54) were randomly divided into three groups: sham-operation group (SO group, n = 18), acute pancreatitis group (AP group, n = 18), and ALA treatment group (ALA group, n = 18). The ALA group was intraperitoneally injected with 1 mg/kg ALA. Each group were further divided into 3 subgroups (n = 6) for testing at 3, 6 and 12 h after treatment. The levels of serum amylase, alanine aminotransferase (ALT) and aspartate aminotransferase (AST) were determined using an automatic biochemical analyzer. The SOD activity and MDA level in liver tissue were measured by colorimetry. Pancreatic gland and liver histological changes were evaluated by hematoxylin and eosin (HE) staining. The expression of ICAM-1 and VCAM-1 in liver tissue was determined by immunohistochemistry. RESULTS: The levels of serum amylase, ALT, AST and hepatic MDA at all time points were significantly increased (3 h: 1 525.17 ± 370.36 vs 134.67 ± 37.46, 101.17 ± 22.33 vs 35.40 ± 5.71, 62.71 ± 19.16 vs 38.25 ± 4.63 and 2.83 ± 0.6 vs 2.12 ± 0.41, all P < 0.01 or 0.05) and SOD activity was decreased (3 h: 43.12 ± 5.87 vs 50.49 ± 7.08, P < 0.05) in the AP group compared with the SO group. Histological examination showed multifocal necrosis and inflammatory cell infiltration in the AP group. The expression of ICAM-1 and VCAM-1 in liver tissue was enhanced in the AP group, but was undetectable in the SO group. In the ALA group, the levels of serum amylase, ALT, AST and hepatic MDA were significantly decreased (3 h: 1 141.50 ± 617.01, 78.11 ± 15.50, 47.16 ± 12.25 and 2.37 ± 0.48, all P < 0.05) and SOD activity was increased (3 h: 45.36 ± 5.67, P < 0.05) compared with the AP group. Hepatic injury was improved and the expression of ICAM-1 and VCAM-1 was significantly decreased in the ALA group compared with the AP group. CONCLUSION: ALA exerts a protective effect against hepatic injury in rats with acute pancreatitis possibly by resisting oxidation and decreasing hepatic expression of ICAM-1 and VCAM-1.