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Background:Previous study has found that harmine inhibited the proliferation of gastric cancer cells by down-regulating cyclooxygenase-2(COX-2)expression. However,its molecular mechanism is not fully clear. Aims:To investigate the effect of harmine on proliferation and apoptosis of gastric cancer cells,and explore the role of PTEN/Akt/MDM2 signaling pathway in this process. Methods:Human gastric adenocarcinoma cell line SGC-7901 and MKN-45 were treated with harmine at different concentrations(2,4,8,16,32 μg/mL)for 24,48,and 72 hours. The cell proliferation and apoptosis were detected by MTT assay and Hoechst staining,respectively. The expressions of PTEN,COX-2, phosphorylated Akt(p-Akt)and p-MDM2 were measured by Western blotting. Results:Harmine dose- and time-dependently inhibited proliferation and induced apoptosis of SGC-7901 and MKN-45 cells. Also,harmine dose-dependently increased PTEN expression,and inhibited p-Akt,p-MDM2 and COX-2 expressions in SGC-7901 and MKN-45 cells. Conclusions:Harmine may inhibit proliferation and induce apoptosis of gastric cancer cells via down-regulating COX-2 expression through PTEN/Akt/MDM2 signaling pathway.
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Background: Previous study has found that ursolic acid (UA) inhibited the proliferation of gastric cancer cells by the down-regulation of cyclooxygenase-2 (COX-2) expression.However,its molecular mechanism is not fully clear.Aims: To investigate the role of adenosine monophosphate-activated protein kinase (AMPK)/signal transducer and activator of transcription 3 (STAT3)/COX-2 signaling pathway in UA-mediated inhibition of gastric cancer cells proliferation.Methods: AMPK-pLVX,AMPK-shRNA,STAT3-pLVX,STAT3-shRNA plasmids were constructed,and then were transfected into human gastric cancer cell lines SGC-7901 and MKN-45,respectively.Gastric cancer cells were cultured with different concentrations of UA for different times.The expressions of phosphorylated AMPK (p-AMPK),phosphorylated STAT3 (p-STAT3) and COX-2 were measured by Western blotting,and cell proliferation was detected by CCK-8 assay.Results: UA dose-and time-dependently increased p-AMPK expression,inhibited p-STAT3 and COX-2 expressions in SGC-7901 and MKN-45 cells.Knockdown of AMPK blocked UA-induced inhibition of STAT3 phosphorylation and COX-2 expression.Overexpression of STAT3 blocked UA-induced down-regulation of COX-2 expression.Knockdown of AMPK and overexpression of STAT3 blocked UA-induced inhibition of proliferation of gastric cancer cells.Conclusions: UA may inhibit the proliferation of gastric cancer cells via down-regulation of COX-2 expression through AMPK/STAT3 pathway.
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Aim Our previous study has found that ur-solic acid( UA) increased intracellular reactive oxygen species ( ROS ) production and adenosine monophos-phate-activated protein kinase ( AMPK ) phosphoryla-tion, inhibited signal transducer and activator of tran-scription 3 ( STAT3 ) phosphorylation and cyclooxygen-ase-2 ( COX-2 ) expression in gastric cancer cells . However , the molecular mechanism by which UA in-hibits COX-2 expression in gastric cancer cells has not been fully clarified .In this study we aimed to further clarify the signal transduction pathways involved in the UA-mediated inhibition of COX-2 expression in gastric cancer cells .Methods Human gastric cancer cell lines SGC-7901 and MKN-45 were routinely cultured in RPMI-1640 medium supplemented with 10% heat-in-activated fetal calf serum .Sub-confluent cell cultures were pre-treated with antioxidant N-acetylcysteine ( NAC) , AMPK activator 5-amino-4-imida-zolecarbox-amide-riboside ( AICAR ) , AMPK inhibitor compound C, or STAT3 inhibitor WP1066 and then treated with or without UA for 24 h.The expression of AMPK and phosphorylated AMPK ( p-AMPK ) , STAT3 and phos-phorylated STAT3 ( p-STAT3 ) , as well as COX-2 was detected by Western blot analysis .Results Antioxi-dant NAC and AMPK inhibitor compound C blocked UA-induced inhibition of STAT 3 phosphorylation and down-regulation of COX-2 expression in gastric cancer cells.Both AMPK activator AICAR and UA inhibited STAT3 phosphorylation and COX-2 expression; the combination of two drugs resulted in further reduction . STAT3 inhibitor WP1066 did not affect UA-induced AMPK phosphorylation , whereas it inhibited STAT3 phosphorylation and COX-2 expression .The inhibitory effects on the STAT3 phosphorylation and COX-2 ex-pression were significantly enhanced when SGC-7901 and MKN-45 cells were treated simultaneously with WP1066 plus UA.Conclusion UA inhibits COX-2 expression in gastric cancer cells , which may be medi-ated through ROS/AMPK/STAT3 signal transduction pathway .
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Objective To evaluate the clinical application of enteral nutrition by nasojejunal tube insertion and by percutaneous endoscopic gastrostomy (PEG) in elderly patients.Methods A total of 65 elderly patients with dysphagia recruited at our department from January 2010 to November 2014 were divided into the nasojejunal tube feeding group (35 cases) and the PEG feeding group (30 cases).Differences between these two groups in nutritional indexes,immunological indexes,complications and mortality were analyzed retrospectively.Results Serum total protein,albumin and prealbumin and upper arm circumferences all increased after treatment with nasojejunal tube feeding or percutaneous endoscopic gastrostomy (P＞0.05).There was overall improvement in nutritional status,as assessed by Nutritional Risk Screening 2002 (NRS2002).Specifically,the before/one month-after-treatment ratio of scores was 3.72±0.91/1.90±0.61 (t=7.24,P＜0.01) for the nasojejunal tube feeding group and 3.52±1.23/2.02±0.53 (t=4.17,P＜0.01) for the PEG feeding group.Compared with NRS2002 scores at one month post-operation,further improvement was achieved at 3 months postoperation both for the nasojejunal tube feeding group (1.89±0.65,t=5.21,P＜0.01) and for the PEG feeding group (1.91±0.62,t=4.40,P＜0.01).There was no difference in the indexes of nutrition,immune status or mortality between the two groups (P＞0.05).Although improvement in CD3+,CD4+,CD8+,CD4+/CD8+,IgA,IgG,and IgM was seen in both groups after operation,the differences did not reach statistical significance (P＞0.05).The incidence of aspiration pneumonia was notably lower (P＜0.05) while the incidence of diarrhea was much higher (P＜0.05) in the nasojejunal tube feeding group than in the PEG feeding group at one month and three months.The two groups had similar causes of death and mortality rates.Conclusion Both nasojejunal tube and PEG feeding can improve the nutritional status of elderly patients with dysphagia.However,the choice for the route of nutrition should be individualized.