Key Laboratory of Digestive System Tumors

Gansu, China

Key Laboratory of Digestive System Tumors

Gansu, China
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Zhang L.-L.,Lanzhou University | Li P.,Lanzhou University | Li P.,Key Laboratory of Digestive System Tumors | Li Y.-M.,Lanzhou University | And 2 more authors.
Drug Development and Industrial Pharmacy | Year: 2012

The aim of this study was to use alginate-chitosan (Alg-CS) hydrogel beads for developing an oral water-soluble drug delivery system, occupying pH-sensitive property and superparamagnetic. Matrine as a model drug was loaded in Alg-CS hydrogel beads to study the release character of the delivery system. The amount of matrine released from the beads was relatively low in pH 2.5 over 8h (34.90%), but nearly all of the initial drug content was released in simulated intestinal fluid (SIF, pH 6.8) within 8h. The results demonstrated that Alg-CS hydrogel beads possess unique pH-dependent swelling behaviors. In addition, the magnetic beads were characterized by Fourier transform infrared spectroscopy, scanning electron microscope, X-ray diffractometry and vibrating-sample magnetometry. Magnetometer measurements data suggested that Alg-CS beads also had superparamagnetic property as well as fast magnetic response. It can be expected that the beads can deliver and release encapsulated anticancer agent at the tumor by the weak magnetic field, and hence could be potential candidates as an orally administered drug delivery system. © 2012 Informa Healthcare USA, Inc.

Ye W.,Lanzhou University | Chen Y.,Lanzhou University | Zhou F.,CAS Lanzhou Institute of Chemical Physics | Wang C.,Lanzhou University | Li Y.,Key Laboratory of Digestive System Tumors
Journal of Materials Chemistry | Year: 2012

Although Al has a lower redox potential [Al 3+/Al, -1.67 V vs. SHE] than most metallic ions, metal galvanic replacement reactions on pure aluminum foil can be hardly observed because of the existence of the thin layer of aluminum oxide, In this work, we develop a facile, economical and general approach to achieve large-scale production of silver and gold dendrites as well as other metal hierarchical micro/nanostructures (Cu, Pt, Pd, Ni, Co and Zn) on commercial aluminum foil in the presence of NaF or NH 4F. Studies of the galvanic replacement reaction by open circuit potential-time (OCP-t) measurements demonstrate that fluoride plays an important role in etching the alumina layer and thus induces the continuous proceeding of the galvanic replacement reaction. The synthesis process is carried out at room temperature and without any templates, surfactants, or special reagents. The obtained silver and gold dendrites show significantly enhanced SERS signals of a self-assembled monolayer of 2-naphthalenethiol and 4-mercaptobenzoic acid, and also could effectively catalyze the reduction reaction of 4-nitrophenol and 2-nitrophenol at room temperature. © 2012 The Royal Society of Chemistry.

Zhang D.-K.,Lanzhou University | Yu J.-J.,Lanzhou University | Li Y.-M.,Key Laboratory of Digestive System Tumors | Wei L.-N.,Lanzhou University | And 3 more authors.
Mediators of Inflammation | Year: 2012

Background. Free radicals and proinflammatory cytokines have been shown to play a critical role in the pathogenesis of ulcerative colitis (UC). Picroliv, a Picrorhiza kurroa derivative, has been demonstrated to have antioxidant and anti-inflammatory effect. The purpose of the study was to investigate the effects of picroliv on experimental model of UC in mice. Materials and Methods. Picroliv was administrated orally by gavage to mice with colitis induced by dextran sulfate sodium (DSS). Disease activity index (DAI), colon length, and histology score were observed. Myeloperoxidase (MPO) activity, and SOD, MDA concentrations were measured by enzyme-linked immunosorbent assay (ELISA) while the expression of cytokine mRNAs was studied by real-time-quantitative polymerase chain reaction and also ELISA. The expression of NF-κB p65 was observed by immunohistochemistry staining and western blotting. Results. A significant improvement was observed in DAI and histological score in mice treated with picroliv, and incerased MPO activity, MDA concentrations, and the expression of IL-1β, TNF-α, and NF-κB p65 in mice with DSS-induced colitis were significantly reduced while decreased SOD level increased following administration of picroliv. Conclusion. The administration of picroliv leads to an amelioration of DSS-induced colitis, suggesting administration of picroliv may provide a therapeutic approach for UC. © 2012 De-Kui Zhang et al.

Wang Y.-Q.,Lanzhou University | Li Y.-M.,Lanzhou University | Li Y.-M.,Key Laboratory of Digestive System Tumors | Li X.,Lanzhou University | And 6 more authors.
World Journal of Gastroenterology | Year: 2013

Aim: To examine transforming growth factor-β1 (TGF-β1) promoter methylation in gastric cancer and to determine if Helicobacter pylori (H. pylori) or interleukin (IL)-1β could induce TGF-β1 hypermethylation in vitro. Methods: We examined the frequency and extent of TGF-β1 promoter methylation using methylationspecific PCR in the gastric tissues from 47 gastric cancer patients and 39 non-gastric cancer subjects. H. pylori infection was confirmed by a positive result from either a serological test, histological analysis or C13 urea breath test. GES-1 and MKN-45 cells co-cultured with H. pylori or treated with IL-1β for 12, 24 and 48 h in vitro tested the effects of H. pylori or IL-1β on TGF-β1. Results: Twenty-four/forty-seven (51%) cases of gastric cancer (GC) tissues showed TGF-β1 promoter methylation, 15/47 (31.9%) cases of matched noncancerous gastric mucosa tissues from the GC patients, and 11/39 (28%) case of the normal gastric mucosa tissues from non-GC subjects showed TGF-β1 promoter methylation (51% vs 28%, P < 0.05). Significantly higher levels of methylation of TGF-β1 were found in the tumor tissues than in non-tumor tissues from GC patients (0.24 ± 0.06 vs 0.17 ± 0.04, P < 0.05) and normal gastric tissues from non-GC subjects (0.24 ± 0.06 vs 0.15 ± 0.03, P < 0.05). TGF-β1 methylation was found in 48.3% of H. pylori -positive gastric mucosal tissues whereas only 23.1% of H. pylori -negative gastric mucosal tissues showed TGF-β1 methylation (48.3% vs 23.1%, P < 0.05). IL-1β appeared to induce a dose-dependent methylation of TGF-β1 and the strongest methylation was observed in GES-1 cells treated with 2.5 ng/mL of IL-1β for 48 h. Further studies showed that pre-treatment of GES-1 cells with 20 ng/mL IL-1RA for 1 h could partially abolish the effect of IL-1β on TGF-β1 methylation. Infection of GES-1 cells by H. pylori was not found to induce significant TGF-β1 promoter methylation. Conclusion: Our data revealed that TGF-β1 promoter is methylated in GC patients. IL-1β may be an important mediator for H. pylori induced gene methylation during GC development. © 2013 Baishideng. All rights reserved.

Liu T.,Lanzhou University | Liu T.,Key Laboratory of Digestive System Tumors | He W.,Lanzhou University | Yan C.,Lanzhou University | And 2 more authors.
Toxicology and Industrial Health | Year: 2011

The roles of reactive oxygen species (ROS) and mitochondrial damage in the cadmium (Cd)-induced injury of liver cells were studied by using N-acetyl-L-cysteine (NAC) and acetyl-L-carnitine hydrochloride (ALCAR). After exposure of experimental rats to cadmium (Cd) for 16 h, mitochondrial membrane potential (MMP), ROS production, glutathione peroxidase (GSH-Px) activity, glutathione (GSH) content, malondialdehyde (MDA) content and DNA single-strand break (DNA-SSB) were analyzed. Loss of MMP, increase of ROS production, inhibition of GSH-Px activity, elevation of GSH content, rise of MDA content and DNA-SSB level suggest the participation of ROS and mitochondrion in Cd-induced injury of liver cell. NAC pretreatment attenuated oxidative stress, reversed the decline in GSH-Px activity and reduced GSH and MDA levels significantly. However, Cd-induced loss in MMP was significantly exacerbated by NAC. For another, ALCAR did not perform as well as NAC in terms of reducing ROS production, restoring GSH-Px activity and reducing GSH content. Nevertheless, it significantly improved the recovery of MMP and reduction of MDA content. In addition, conspicuous DNA damage was observed in the samples treated with NAC or ALCAR, indicating Cd could attack DNA through other pathways. These results suggest that oxidative stress or mitochondrial impairment plays a main role in different injuries respectively. © The Author(s) 2011.

He W.,Lanzhou University | He W.,Key Laboratory of Digestive System Tumors | Liu T.,Key Laboratory of Digestive System Tumors | Liu T.,Lanzhou University | And 4 more authors.
Molecular Diagnosis and Therapy | Year: 2012

Background and Objective: Poly(adenosine diphosphate [ADP]-ribose) polymerase 1 (PARP1), a protein involved in the DNA repair mechanism, plays an important role in carcinogenesis. In this study, we investigated whether single nucleotide polymorphisms of PARP1 contribute to gastric cancer (GC) and its precursor lesions (gastric precancerous lesions; GPL) in a case-control study conducted in the Hexi area of China, a high-risk area for GC. Methods: PARP1 162C>G(Phe54Leu) and 2819A>G(Lys940Arg) polymorphisms were genotyped by realtime PCR using a TaqMan assay in 140 GC cases, 110 GPL cases, and 120 controls. Data were statistically analyzed using the chi-squared test and a logistic regression model. Results: The presence of the PARP1 2819G allele was associated with an increased risk of GC (odds ratio [OR] 2.354; 95% CI 1.140, 4.861; p = 0.018), especially for cardia GC and diffuse-type GC (ORs 2.988 and 3.784, respectively). We also observed an interaction between Helicobacter pylori infection, GC family history, and the presence of the PARP1 2819G allele. In contrast, the PARP1 162C>G polymorphism was not significantly associated with GPL or GC. Conclusion: The study suggests that the PARP1 2819G allele is associated with an increased risk of GC. In addition, H. pylori-positive status and family history jointly contribute to a higher risk of GC. ©2012 Adis Data Information BV. All rights reserved.

Li Y.,Lanzhou University | Li Y.,Key Laboratory of Digestive System Tumors | Zhang H.,Lanzhou University | Chen Y.,Key Laboratory of Digestive System Tumors | Chen Y.,Lanzhou University
PLoS ONE | Year: 2011

MicroRNAs (miRNAs) are small, noncoding RNAs that play an important role in many key biological processes, including development, cell differentiation, the cell cycle and apoptosis, as central post-transcriptional regulators of gene expression. Recent studies have shown that miRNAs can act as oncogenes and tumor suppressors depending on the context. The present work focuses on the physiological significance of miRNAs and their role in regulating the switching behavior. We illustrate an abstract model of the Myc/E2F/miR-17-92 network presented by Agudaet al. (2008), which is composed of coupling between the E2F/Myc positive feedback loops and the E2F/Myc/miR-17-92 negative feedback loop. By systematically analyzing the network in close association with plausible experimental parameters, we show that, in the presence of miRNAs, the system bistability emerges from the system, with a bistable switch and a one-way switch presented by Agudaet al. instead of a single one-way switch. Moreover, the miRNAs can optimize the switching process. The model produces a diverse array of response-signal behaviors in response to various potential regulating scenarios. The model predicts that this transition exists, one from cell death or the cancerous phenotype directly to cell quiescence, due to the existence of miRNAs. It was also found that the network involving miR-17-92 exhibits high noise sensitivity due to a positive feedback loop and also maintains resistance to noise from a negative feedback loop. © 2011 Li et al.

Sun P.,Lanzhou University | Sun P.,Key Laboratory of Digestive System Tumors | Li P.,Lanzhou University | Li P.,Key Laboratory of Digestive System Tumors | And 4 more authors.
Journal of Biomedical Materials Research - Part B Applied Biomaterials | Year: 2011

A chitosan(CS)-tripolyphosphate (TPP) hydrogel bead was prepared by the ionic gelation method for the controlled delivery of glipizide. The structure and surface morphology of the beads were characterized by FT-IR and SEM, separately. Factors influencing the swelling behavior of the hydrogel beads were also investigated, such as CS concentration (X1), TPP concentration (X2), the weight ratio of drug to polymer (X3), crosslinking time (X4), and the volume ratio of CS to TPP (X 5). In addition, the swelling property and the delivery behavior of the hydrogel bead was studied as well. With decreasing of pH value, the swelling ratio of the bead was increasing. The swelling ratio of hydrogel bead at pH 1.5 was relatively high, while this value was low at pH 6.8. The amount of glipizide released from the hydrogel bead at pH 1.5 was about 90%, while this value approached 36% at pH 6.8. The results clearly suggested that the CS-TPP hydrogel beads were used as a pH-sensitive controlled release system for the delivery of glipizide. © 2011 Wiley Periodicals, Inc.

Meng W.-B.,Key Laboratory of Digestive System Tumors | Meng W.-B.,Lanzhou University | Li X.,Key Laboratory of Digestive System Tumors | Li X.,Lanzhou University | And 6 more authors.
World Journal of Gastroenterology | Year: 2011

AIM: To compare non-liquid and clear-liquid diets, and to assess whether the latter is the optimal treatment for mild acute pancreatitis. METHODS: The Cochrane Library, PUBMED, EMBASE, EBM review databases, Science Citation Index Expanded, and several Chinese databases were searched up to March 2011. Randomized controlled trials (RCTs) that compared non-liquid with clear-liquid diets in patients with mild acute pancreatitis were included. A meta-analysis was performed using available evidence from RCTs. RESULTS: Three RCTs of adequate quality involving a total of 362 participants were included in the final analysis. Compared to liquid diet, non-liquid diet significantly decreased the length of hospitalization [mean difference (MD): 1.18, 95% CI: 0.82-1.55; P<0.00001] and total length of hospitalization (MD: 1.31, 95% CI: 0.45-2.17; P = 0.003). The subgroup analysis showed solid diet was more favorable than clear liquid diet in the length of hospitalization, with a pooled MD being -1.05 (95% CI: -1.43 to -0.66; P<0.00001). However, compared with clear liquid diet, both soft and solid diets did not show any significant differences for recurrence of pain after re-feeding, either alone [relative risk (RR): 0.95; 95% CI: 0.51-1.87; P = 0.88] and (RR: 1.22; 95% CI: 0.69-2.16; P = 0.49), respectively, or analyzed together as non-liquid diet (RR: 0.80; 95% CI: 0.47-1.36; P = 0.41). CONCLUSION: The non-liquid soft or solid diet did not increase pain recurrence after re-feeding, compared with the clear-liquid diet. The non-liquid diet reduced hospitalization. © 2011 Baishideng. All rights reserved.

He W.-T.,Lanzhou University | He W.-T.,Key Laboratory of Digestive System Tumors | Liu T.,Lanzhou University | Liu T.,Key Laboratory of Digestive System Tumors | And 3 more authors.
Asian Pacific Journal of Cancer Prevention | Year: 2014

Background: The Chinese Hui ethnic group has diverse origins, including Arab, Persian, Central Asian, and Mongol. The standardized mortality rate of gastric cancer in the Hui population is higher than the overall Chinese population. In this study, we investigated whether COX-2-765G>C polymorphism, an extensively studied polymorphism, contributes to gastric cancer and its precursor lesions (GPL) in the Chinese Hui ethnic group. Materials and Methods: COX-2-765G>C polymorphism was determined by pyrosequencing in 100 gastric cancer cases, 102 gastric cancerand its precursor lesions cases and 105 controls. Data were statistically analyzed using Chi-square tests and logistic regression models. Results: Among the Chinese Hui ethnic group COX-2 -765 C allele carriers were at increased risk for gastric cancer (OR=1.977, 95%CI=1.104-3.541). We also found an interaction between COX-2 -765 C carriers and Helicobacter pylori infection and eating pickled vegetables. Conclusions: Our findings suggest a multi-step process of gene-environment interaction contributes to gastric carcinogenesis.

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