ABSTRACT
AIM:To investigate the effect of doublecortin-like kinase 1(DCLK1)on the biological properties of gastric cancer stem cells,and to explore its possible mechanism.METHODS:Serum-free suspension culture of gastric cancer stem cells and targeted inhibition of DCLK1 activity in gastric cancer stem cells with DCLK1 inhibitor DCLK1-IN-1 were performed.The expression levels of DCLK1,stemness-related proteins(SOX2 and OCT4),proliferation-related pro-teins(cyclin D1 and c-MYC),drug resistance-related proteins(ABCG2 and TOP2A),epithelial-mesenchymal transition-related proteins(E-cadherin,vimentin and Snail),and PI3K/AKT/mTOR signaling pathway-related proteins in gastric cancer stem cells were examined by Western blot.The effects of DCLK1 on viability and drug resistance of gastric cancer stem cells were determined by CCK-8 assay,and the effects of DCLK1 on self-renewal of gastric cancer stem cells were de-termined by methylcellulose spheroid-forming assay.Wound-healing and Transwell assays were performed to assess the ef-fect of DCLK1 on the migration and invasion of gastric cancer stem cells.RESULTS:The expression levels of DCLK1 and stemness-related proteins SOX2 and OCT4 in gastric cancer stem cells were significantly higher than those in parental cells(P＜0.01).The proliferation,drug resistance,migration and invasion of gastric cancer stem cells in DCLK1 inhibi-tion group were significantly lower than those in Sphere cell group(P＜0.01).The expression levels of proliferation-related proteins(c-MYC and cyclin D1)and drug resistance-related proteins(TOP2A and ABCG2)were down-regulated,the ex-pression of epithelial marker E-cadherin was up-regulated,the expression of mesenchymal markers vimentin and Snail was down-regulated,and the expression levels of PI3K/AKT/mTOR signaling pathway-related proteins and their phosphoryla-tion levels were reduced in DCLK1 inhibition group(P＜0.05).CONCLUSION:DCLK1 is highly expressed in gastric cancer stem cells,which may be involved in the proliferation,drug resistance and invasion of gastric cancer stem cells by regulating PI3K/AKT/mTOR signaling pathway.It suggests that DCLK1 can be used as a potential target for gastric cancer stem cells.
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Objective:To investigate the biological characteristics of monoclonal antibodies against avian influenza virus (AIV).Methods:Monoclonal antibodies (mAbs) against AIV H5N1 were prepared and it′s characteristics were identified including subtype,titer,hemagglutination inhibition activity and cross-reactivity with other influenza viruses.Besides,Western blot and immuno-histochemical staining methods were conducted to test the combination of antibodies and antigen ( H5N1 ) and human normal tissues.Results:Immunohistochemical analysis showed that 2 mAbs (H5-32 and H5-35) cross-reacted with human tissues kidney and pancreas respectively.Conclusion:These data indicated that there have some association between the AIV H 5N1 with human tissues, which may provide reference for the study on avian influenza virus infection and pathogenicity .
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[ ABSTRACT] AIM:To study the role of Radix Pseudostellariae polysaccharide ( RPP) in hepatic insulin resist-ance.METHODS:Six-week-old C57BL/6J mice were randomly divided into low-fat diet (LFD) control group and high-fat diet ( HFD) model group.After 16 weeks, intraperitoneal pyruvate tolerance test ( IPPTT) was performed to determine the establishment of the HFD-induced hepatic insulin resistance model.HFD containing RPP (500 mg/kg) was given for 4 consecutive weeks.IPPTT, liver malondialdehyde ( MDA) level and liver mitochondrial MDA level were measured.The protein levels of p-AKT (Ser473/Thr308), p-AMPK, nuclear factor E2-related factor 2 (Nrf2), NQO1 and IκBαin the liver tissues were measured by Western blot.RESULTS:After administration of RPP, a significant reduction in the levels of blood glucose and hepatic mitochondrial MDA was observed.The levels of p-AKT ( Ser473/Thr308) and p-AMPK were significantly elevated in the liver tissues.The hepatic IκBαlevels were up-regulated.RPP also enhanced the expression of Nrf2 system-regulated proteins NQO1 and HO-1 in the liver tissues.CONCLUSION:Radix Pseudostellariae polysaccha-rides effectively reduce HFD-induced hepatic insulin resistance in C57BL/6J mice and improves liver glucose metabolism by ameliorating HFD-impaired hepatic transduction of insulin signaling, activating Nrf2-associated signaling and inhibiting the expression of inflammatory signaling proteins.
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To study the effect of Tibetan medicine Zuotai on the activity, protein and mRNA expression of CYP1A2 and NAT2, three different doses (1.2, 3.8 and 12 mg x kg(-1)) of Zuotai were administrated orally to rats once a day or once daily for twelve days, separately. Rats were administrated orally caffeine (CF) on the second day after Zuotai administration, and the urine concentration of CF metabolite 5-acetylamino-6-formylamino-3-methyl-uracil (AFMU), 1-methyluric acid (1U), 1-methylxanthine (1X), 1, 7-dimethylxanthine (17U) at 5 h after study drug administration was determined by RP-HPLC. The activity of CYP1A2 and NAT2 was evaluated by the ratio of metabolites (AFMU+1X+1U)/17U and the ratio of AFMU/(AFMU+1X+1U), respectively. The protein and mRNA expression of CYP1A2 and NAT2 were determined by ELISA and RT-PCR method, respectively. After single administration of Zuotai 3.8 mg x kg(-1) and repeated administration of Zuotai 3.8 and 12 mg x kg(-1), the activity of CYP1A2 and NAT2 decreased significantly compared with control group and there was no significant difference between other dose group and control group. The protein expression of CYP1A2 was significant lower than that in control group after repeated administration of Zuotai 12 mg x kg(-1), and the mRNA expression of CYP1A2 decreased significantly compared with that of control group after single administration of Zuotai 3.8 mg x kg(-1) and repeated admistration of Zuotai 12 mg x kg(-1), separately. The protein expression of NAT2 decreased significantly compared with that of control group after single and repeated administration of Zuotai 3.8 mg x kg(-1), respectively, and the mRNA expression of CYP1A2 decreased significantly compared with control group after single administration of Zuotai 3.8 mg x kg(-1). This study found that Tibetan medicine Zuotai had significant effect on the activity, protein and mRNA expression of CYP1A2 and NAT2.
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This study is to investigate the effect of high altitude hypoxia on the activity and protein expression of CYP2C9 and CYP2C19. Rats from plain (P) and rats with acute middle altitude hypoxia (AMH), chronic middle altitude hypoxia (CMH), acute high altitude hypoxia (AHH) and chronic high altitude hypoxia (CHH) were administered orally phenytoin sodium (PHT) and omeprazole (OMZ) to evaluate the activity of CYP2C9 and CYP2C19, separately. The serum concentrations of PHT and metabolite 4'-hydroxyphenytoin (HPPH) at 12 h after treatment and the serum concentrations of OMZ and metabolite 5-hydroxy omeprazole (5-OHOMZ) at 3 h after treatment were determined by RP-HPLC. The activity of CYP2C9 and CYP2C19 was evaluated by the ratio of HPPH to PHT and the ratio of 5-OHOMZ to OMZ, respectively. The protein expressions of CYP2C9 and CYP2C19 were determined by ELISA method. The activities of CYP2C9 (HPPH/PHT) in P, AMH, CMH, AHH and CHH were 0.67 +/- 0.31, 0.75 +/- 0.29, 0.76 +/- 0.23, 0.79 +/- 0.31 and 0.75 +/- 0.18, respectively, and the activities of CYP2C19 (5-OHOMZ/OMZ) in P, AMH, CMH, AHH and CHH were 0.17 +/- 0.06, 0.20 +/- 0.10, 0.11 +/- 0.05, 0.37 +/- 0.13 and 0.19 +/- 0.05, respectively. The protein expressions of CYP2C9 in P, AMH, CMH, AHH and CHH were 4.20 +/- 1.27, 3.95 +/- 0.81, 3.93 +/- 1.11, 4.32 +/- 1.03 and 4.12 +/- 0.86 ng x g(-1), respectively, and the protein expressions of CYP2C19 in P, AMH, CMH, AHH and CHH were 3.91 +/- 1.82, 3.63 +/- 2.07, 2.55 +/- 0.85, 4.78 +/- 2.37 and 3.51 +/- 1.03 ng x g(-1), respectively. The activities and protein expressions of CYP2C9 in AMH, CMH, AHH and CHH were not significantly different with those of P. The protein expressions of CYP2C19 in AMH, CMH, AHH and CHH were not significantly different with those of P, but the activity of CYP2C19 in AHH was significantly higher than that of P. This study found significant changes in the activity of CYP2C19 under the special environment of acute high altitude hypoxia.
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The paper is to report the pharmacokinetics of sulfamethoxazole in healthy Han volunteers living at plain (PH) and native Han and Tibetan healthy volunteers living at high altitude (HNH and HNT). After healthy volunteers were administrated orally cotrimoxazole tablets, plasma concentration of sulfamethoxazole and metabolite N4-acetylsulfamethoxazole was determined by RP-HPLC, and plasma concentration-time data were analyzed by DAS 2.0 software to get the related pharmacokinetic parameters. The main pharmacokinetic parameters t(1/2) of sulfamethoxazole in PH, HNH and HNT were, respectively, 9.30 +/- 1.11, 10.99 +/- 1.23 and 10.44 +/- 1.05 h; tmax were 1.4 +/- 0.3, 2.0 +/- 1.1 and 1.8 +/- 0.4 h; Cmax were 94.42 +/- 15.26, 89.33 +/- 7.67 and 87.43 +/- 11.61 micro x mL(-1); AUC(0-t) were 1202.5 +/- 238.3, 1 434.7 +/- 193.9 and 1302.8 +/- 103.0 microg x h x mL(-1); AUC(0-infinity) were 1240.7 +/- 255.3, 1511.5 +/- 211.9 and 1363.9 +/- 116.5 microg x h x mL(-1); CL were 1.01 +/- 0.22, 0.81 +/- 0.12 and 0.89 +/- 0.08 L x h(-1) x kg(-1); V were 13.27 +/- 1.73, 12.81 +/- 2.15 and 13.28 +/- 1.20 L x kg(-1). Sulfamethoxazole pharmacokinetic parameters of HNH and HNT were significantly different from that of PH. The t(1/2) was significantly higher and the CL was significantly lower in HNH and HNT than that in PH, and the AUC(0-infinity) was significantly lower in HNT compared with HNH. This study found significant changes in the disposition of sulfamethoxazole under the special environment of high altitude hypoxia. This finding may provide some references for clinical rational application of sulfamethoxazole in HNH and HNT.