Mengyao Ji

Thymoquinone inhibits growth and augments 5-fluorouracil-induced apoptosis in gastric cancer cells both in vitro and in vivo.

Thymoquinone (TQ), a component derived from the bioactive constituent of black seed (Nigella sativa), has been shown to exert biological activity on various types of human cancers. However, there are few studies addressing its effects on gastric cancer. Here, we present the first report describing the chemosensitizing effect of thymoquinone and 5-fluorouracil (5-FU) on gastric cancer cells both in vitro and in vivo. Studies have shown that pretreatment with TQ significantly increased the apoptotic effects induced by 5-FU in gastric cancer cell lines in vitro. Moreover, we found that TQ enhanced the 5-FU-induced killing of gastric cancer cells by mediating the downregulation of the anti-apoptotic protein bcl-2, the upregulation of the pro-apoptotic protein bax, and the activation of both caspase-3 and caspase-9. In addition to the in vitro results, it has been shown that the combined treatment of TQ with 5-FU represents a significantly more effective antitumor agent than either agent alone in a xenograft tumor mouse model. These data suggest that the TQ/5-FU combined treatment induces apoptosis by enhancing the activation of both caspase-3 and caspase-9 in gastric cancer cells. These results, which provide molecular evidence both in vitro and in vivo, support our conclusion that thymoquinone can activate caspase-3 and caspase-9 and thus result in the chemosensitisation of gastric cancer cells to 5-FU-induced cell death.

EBP50 gene transfection promotes 5-fluorouracil-induced apoptosis in gastric cancer cells through Bax- and Bcl-2-triggered mitochondrial pathways.

5-Fluorouracil (5-FU) plays an important role in the chemotherapy of advanced gastric cancer. However, genetic factors that affect therapeutic efficacy of 5-FU warrant further investigation. In the present study, using stable transfection of the ezrin-radixin-moesin-binding phosphoprotein 50 (EBP50) gene, we explored the genetic influences on 5-FU-induced apoptosis of human gastric cancer cells. Stable overexpression of the EBP50 gene was determined by reverse transcription polymerase chain reaction (RT-PCR) assay and western blot analysis. After treatment with 5-FU, cell growth activities in vitro were investigated by MTT assay. Cell apoptosis was evaluated by Hoechst 33258 staining and flow cytometry of Annexin V-FITC/PI staining. Compared with the BGC823 or BGC823/neo cells, EBP50 mRNA and protein levels in the BGC823/EBP50 cells (EBP50-transfected BGC823 cells) were markedly higher. Chemosensitivity and apoptosis rates of the BGC823/EBP50 cells were higher compared to the BGC823 and BGC823/neo cells following treatment with 5-FU. Stable overexpression of extrinsic EBP50 distinctly increases the 5-FU-induced apoptosis of gastric cancer cells, and is a novel strategy by which to improve the chemosensitivity of gastric cancer to 5-FU.

TNF-α-308 polymorphism and risk of digestive system cancers: a meta-analysis.

AIM To evaluate the association between the tumour necrosis factor alpha-308 (TNF-α-308) gene polymorphism and the risk of digestive system cancers. METHODS All eligible case-control studies published up to December 2012 were identified by searching PubMed, Web of Science, Embase and China National Knowledge Internet without language restrictions. The risk of digestive system cancers associated with the TNF-α-308 polymorphism was estimated for each study using odds ratio (OR) together with its 95%CI, respectively. Cochrane Collaboration RevMan 5.1 was used to perform the analysis. A χ²-test-based Q statistic test and an I² test were performed to assess the between-study heterogeneity. When the Q test was significant (P < 0.05) or I² > 50%, the random effects model was used, otherwise the fixed effects model was used. RESULTS Fifty-eight studies from fifty-five publications with a total of 9986 cancer patients and 15511 healthy controls were included. Overall, a significant association was found between the TNF-α-308 polymorphism and the risk of digestive system cancers [dominant model: OR = 1.23, 95%CI: 1.09-1.39, (G/A) vs (G/G): OR = 1.15, 95%CI: 1.02-1.28, (A/A) vs (G/G): OR = 1.44, 95%CI: 1.19-1.73, recessive model: OR = 1.38, 95%CI: 1.15-1.66]. Furthermore, when the analysis was stratified by ethnicity, similar results were observed in both the Asian and Caucasian populations, except for the dominant model and heterozygote comparisons in the Asian population [dominant model: OR = 1.24, 95%CI: 0.99-1.56, (G/A) vs (G/G): OR = 1.09, 95%CI: 0.96-1.24]. When the cancer type subgroups were examined, similar results were detected in gastric and hepatocellular carcinomas; however, no significant association was observed among other digestive system cancers. CONCLUSION The TNF-α-308 gene polymorphism may be significantly associated with the risk of gastric and hepatocellular carcinomas, but not colorectal, pancreatic, or oesophageal cancer, in the Asian population.

Hugl-1 induces apoptosis in esophageal carcinoma cells both in vitro and in vivo.

AIM To determine whether the human giant larvae homolog 1 gene (Hugl-1/Llg1/Lgl1) exerts tumor suppressor effects in esophageal cancer. METHODS We constructed a Hugl-1 expression plasmid, pEZ-M29-Hugl1, for gene transfection. We transfected the pEZ-M29-Hugl1 plasmid into Eca109 esophageal cancer cell lines with Lipofectamine 2000 to overexpress Hugl-1. Real-time reverse transcription-polymerase chain reaction (RT-PCR) and Western blotting were performed to determine the effects of the plasmid on Hugl-1 expression. In vitro cell proliferation and apoptosis were examined separately by cell counting Kit-8 (CCK-8) assay, flow cytometry, and Western blotting before and after the transfection of the plasmid into Eca109 cells. Cell cycle distribution was assessed with flow cytometry. The effect of Hugl-1 overexpressing on tumor growth in vivo was performed with a xenograft tumor model in nude mice. Expression of Hugl-1 in xenograft tumor was analyzed by immunohistochemistry. The transferase-mediated dUTP nick end-labeling (TUNEL) technique was performed to detect and quantitate apoptotic cell. RESULTS The transfection efficiency was confirmed with real-time RT-PCR and Western blotting. Our results show that compared with control groups the mRNA levels and protein levels of Hugl-1 in pEZ-M29-Hugl1-treated group were remarkably increased (P < 0.05). The CCK-8 assay demonstrated that the growth of cells overexpressing Hugl-1 was significantly lower than control cells. Cell cycle distribution showed there was a G0/G1 cell cycle arrest in cells overexpressing Hugl-1 (64.09% ± 3.14% vs 50.32% ± 4.60%, 64.09% ± 3.14% vs 49.13% ± 2.24%). Annexin V-fluorescein isothiocyanate revealed that apoptosis was significantly increased in cells overexpressing Hugl-1 compared with control group (17.33% ± 4.76% vs 6.90% ± 1.61%, 17.33% ± 4.76% vs 6.27% ± 0.38%). Moreover, we found that Hugl-1 changes the level of the anti-apoptotic protein Bcl-2 and the pro-apoptotic protein Bax and the activation of both caspase-3 and caspase-9. With a TUNEL assay, we found that Hugl-1 markedly increased the apoptosis rate of Eca109 cells in vivo (60.50% ± 9.11% vs 25.00% ± 12.25%). It was shown that Hugl-1 represents a significantly more effective tumor suppressor gene alone in a xenograft tumor mouse model. This data suggest that Hugl-1 inhibited tumor growth and induced cell apoptosis in vivo. CONCLUSION These results suggest that Hugl-1 induces growth suppression and apoptosis in a human esophageal squamous cell carcinoma cell line both in vitro and in vivo.

Decreased EGR3 expression is related to poor prognosis in patients with gastric cancer

The early growth response (EGR) family has a highly conserved DNA-binding domain and encodes zinc finger proteins, which show suppressive effects on tumour growth. However, the expression and significance of EGR3 in gastric cancer are still unknown. In this study, real-time PCR, immunohistochemistry and western blot assays were performed to detect the expression of EGR3 in gastric cancer tissues and matched non-tumour tissues and to further analyse the EGR3 expression associated with clinical pathological factors, including prognosis. Our results showed that EGR3 expression was significantly lower in gastric cancer tissues compared with matched non-tumour tissues and that patients with lower EGR3 expression had a poorer prognosis compared with patients with higher EGR3 expression. Our results suggest that decreased EGR3 expression might play a critical role in the differentiation, proliferation, metastasis and progression of gastric cancer cells and may also be a potential diagnostic marker for gastric cancer.

Tumor suppressor function of ezrin-radixin-moesin-binding phosphoprotein-50 through β-catenin/E-cadherin pathway in human hepatocellular cancer.

AIM To determine the effect and molecular mechanism of ezrin-radixin-moesin-binding phosphoprotein-50 (EBP50) in hepatocellular carcinoma (HCC). METHODS Three human HCC cell lines, i.e., SM-MC7721, HepG2 and Hep3B, were used. We transfected the Pbk-CMV-HA-EBP50 plasmid into SMMC7721 cells with Lipofectamine 2000 to overexpress EBP50. Western blotting were performed to determine the effects of the plasmid on EBP50 expression and to detect the expression of β-catenin and E-cadherin before and after the transfection of the plasmid into SMMC7721 cells. In vitro cell proliferation was assessed with a Cell Counting Kit-8 (CCK-8) assay. Cell cycle distribution was assessed with flow cytometry. Invasion and migration ability of before and after the transfection were determined with a transwell assay. Cell apoptosis was demonstrated with Annexin V-FITC. The effect of EBP50 overexpressing on tumor growth in vivo was performed with a xenograft tumor model in nude mice. RESULTS The transfection efficiency was confirmed with Western blotting (1.36 ± 0.07 vs 0.81 ± 0.09, P < 0.01). The CCK8 assay demonstrated that the growth of cells overexpressing EBP50 was significantly lower than control cells (P < 0.01). Cell cycle distribution showed there was a G0/G1 cell cycle arrest in cells overexpressing EBP50 (61.3% ± 3.1% vs 54.0% ± 2.4%, P < 0.05). The transwell assay showed that cell invasion and migration were significantly inhibited in cells overexpressing EBP50 compared with control cells (5.8 ± 0.8 vs 21.6 ± 1.3, P < 0.01). Annexin V-FITC revealed that apoptosis was significantly increased in cells overexpressing EBP50 compared with control cells (14.8% ± 2.7% vs 3.4% ± 1.3%, P < 0.05). The expression of β-catenin was downregulated and E-cadherin was upregulated in cells overexpressing EBP50 compared with control cells (0.28 ± 0.07 vs 0.56 ± 0.12, P < 0.05; 0.55 ± 0.08 vs 0.39 ± 0.07, P < 0.05). In vivo tumor growth assay confirmed that up-regulation of EBP50 could obviously slow the growth of HCC derived from SMMC7721 cells (28.9 ± 7.2 vs 70.1 ± 7.2, P < 0.01). CONCLUSION The overexpression of EBP50 could inhibit the growth of SMMC7721 cells and promote apoptosis by modulating β-catenin, E-cadherin. EBP50 may serve as a potential therapeutic target in HCC.

EBP50 regulates the apoptosis of pancreatic cancer cells by decreasing the expression levels of Bcl-2.

Increasing evidence has demonstrated that ezrin-radixin-moesin (ERM)-binding phosphoprotein 50 (EBP50) is involved in the malignant transformation of numerous human cancers. The present study investigated the involvement of EBP50 overexpression in the tumorigenicity of pancreatic cancer (PC). The results revealed that overexpression of EBP50 suppressed cell growth, promoted cell apoptosis and arrested G1-to-S phase progression in two human PC cell lines. Overexpression of EBP50 also suppressed B-cell lymphoma 2 (Bcl-2) expression. Furthermore, nude mouse tumor xenograft models were established by the subcutaneous injection of cell lines stably transfected with an EBP50-expressing plasmid. The in vivo data indicated that overexpression of EBP50 inhibited the growth of the PC tumors and induced cell apoptosis. Thus, the present study demonstrated that EBP50 overexpression induces growth inhibition and apoptosis in PC by decreasing Bcl-2 expression. The results suggest that EBP50 may function as a potential tumor suppressor in vivo and in vitro.

Proton pump inhibitor for non-erosive reflux disease: a meta-analysis.

AIM To evaluate the efficacy, safety and influential factors of proton pump inhibitor (PPI) treatment for non-erosive reflux disease (NERD). METHODS PubMed, MEDLINE, EMBASE and the Cochrane Library were searched up to April 2013 to identify eligible randomized controlled trials (RCTs) that probed into the efficacy, safety and influential factors of PPI treatment for NERD. The rates of symptomatic relief and adverse events were measured as the outcomes. After RCT selection, assessment and data collection, the pooled RRs and 95%CI were calculated. This meta-analysis was performed using the Stata 12.0 software (Stata Corporation, College Station, Texas, United States). The level of evidence was estimated by the Grading of Recommendations Assessment, Development and Evaluation system. RESULTS Seventeen RCTs including 6072 patients met the inclusion criteria. The results of the meta-analysis showed that PPI treatment was significantly superior to H2 receptor antagonists (H2RA) treatment (RR = 1.629, 95%CI: 1.422-1.867, P = 0.000) and placebo (RR = 1.903, 95%CI: 1.573-2.302, P = 0.000) for the symptomatic relief of NERD. However, there were no obvious differences between PPI and H2RA (RR = 0.928, 95%CI: 0.776-1.110, P = 0.414) or PPI and the placebo (RR = 1.000, 95%CI: 0.896-1.116, P = 0.997) regarding the rate of adverse events. The overall rate of symptomatic relief of PPI against NERD was 51.4% (95%CI: 0.433-0.595, P = 0.000), and relief was influenced by hiatal hernia (P = 0.030). The adverse rate of PPI against NERD was 21.0% (95%CI: 0.152-0.208, P = 0.000), and was affected by hiatal hernia (P = 0.081) and drinking (P = 0.053). CONCLUSION PPI overmatched H2RA on symptomatic relief rate but not on adverse rate for NERD. Its relief rate and adverse rate were influenced by hiatal hernia and drinking.

Adiponectin polymorphisms and non-alcoholic fatty liver disease risk: A meta-analysis

The adiponectin polymorphism has been implicated in susceptibility to non‐alcoholic fatty liver disease (NAFLD), but the results remain inconclusive. The aim of this meta‐analysis is to investigate the association between adiponectin polymorphisms and NAFLD risk.

EBP50 inhibits pancreatic cancer cell growth and invasion by targeting the β-catenin/E-cadherin pathway

Ezrin-radixin-moesin (ERM)-binding phosphoprotein 50 (EBP50) has previously been demonstrated to be associated with the malignant transformation of numerous types of human cancer. The aim of the present study was to investigate the effect of EBP50 overexpression on pancreatic cancer and the underlying mechanism. Reverse transcription-quantitative polymerase chain reaction was used to detect the expression of EBP50 in human pancreatic cancer tissue specimens. Furthermore, pBK-CMV-HA-EBP50 and the pBK-CMV-HA vectors were transfected into pancreatic cancer cells and the effect of EBP50 upregulation on the proliferation and invasion of the cells was investigated. In addition, the effect of EBP50 overexpression on β-catenin and E-cadherin expression was evaluated. The results revealed that overexpression of EBP50 suppressed cell growth and invasion in two human pancreatic cancer cell lines. Overexpression of EBP50 also suppressed β-catenin expression and increased E-cadherin expression. Thus, the present study demonstrated that EBP50 inhibits pancreatic cancer cell growth and invasion through targeting the β-catenin/E-cadherin pathway. The results suggest that EBP50 may function as a potential tumor suppressor and thus may serve as a potential therapeutic target.