OBJECTIVES: Fluorouracil chemotherapeutic drugs are the classic treatment drugs of gastric cancer. But the problem of drug resistance severely limits their clinical application. This study aims to investigate whether hypoxia microenvironment affects gastric cancer resistance to 5-fluorouracil (5-FU) and discuss the changes of gene and proteins directly related to drug resistance under hypoxia condition. METHODS: Gastric cancer cells were treated with 5-FU in hypoxia/normoxic environment, and were divided into a Normoxic+5-FU group and a Hypoxia+5-FU group. The apoptosis assay was conducted by flow cytometry Annexin V/PI double staining. The real-time reverse transcription-polymerase chain reaction (RT-PCR) and Western blotting were used to detect the expression level of hypoxia inducible factor-1α (HIF-1α), multidrug resistance (MDR1) gene, P-glycoprotein (P-gp), and vascular endothelial growth factor (VEGF) which were related to 5-FU drug-resistance. We analyzed the effect of hypoxia on the treatment of gastric cancer with 5-FU. RESULTS: Compared with the Normoxic+5-FU group, the apoptosis of gastric cancer cells treated with 5-FU in the Hypoxia+5-FU group was significantly reduced (P<0.05), and the expression of apoptosis promoter protein caspase 8 was also decreased. Compared with the the Normoxic+5-FU group, HIF-1α mRNA expression in the Hypoxia+5-FU group was significantly increased (P<0.05), and the mRNA and protein expression levels of MDR1, P-gp and VEGF were also significantly increased (all P<0.05). The increased expression of MDR1, P-gp and VEGF had the same trend with the expression of HIF-1α. CONCLUSIONS Hypoxia is a direct influencing factor in gastric cancer resistance to 5-FU chemotherapy. Improvement of the local hypoxia microenvironment of gastric cancer may be a new idea for overcoming the resistance to 5-FU in gastric cancer.
Humans ; Fluorouracil/therapeutic use* ; Vascular Endothelial Growth Factor A/metabolism* ; Stomach Neoplasms/drug therapy* ; Drug Resistance, Multiple ; Vascular Endothelial Growth Factors/metabolism* ; Hypoxia ; ATP Binding Cassette Transporter, Subfamily B/genetics* ; ATP Binding Cassette Transporter, Subfamily B, Member 1/genetics* ; Cell Line, Tumor ; Cell Hypoxia ; RNA, Messenger/metabolism* ; Hypoxia-Inducible Factor 1, alpha Subunit/genetics* ; Tumor Microenvironment

OBJECTIVETo investigate the effect of extracellular signal-regulated kinase (ERK) signaling pathway on the endothelial differentiation of periodontal ligament stem cells (PDLSC).

METHODSHuman PDLSC was cultured in the medium with vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (b-FGF) to induce endothelial differentiation. Endothelial inducing cells was incubated with U0126, a specific p-ERK1/2 inhibitor. PDLSC from one person were randomly divided into four groups: control group, endothelial induced group, endothelial induced+DMSO group and endothelial induced+U0126 group. The protein expression of the p-EKR1/2 was analyzed by Western blotting at 0, 1, 3, 6 and 12 hours during endonthelial induction. The mRNA expressions of CD31, VE-cadherin, and VEGF were detected by quantitative real-time reverse transcriptase polymerase chain reaction (qRT-PCR) after a 7-day induction. The proportion of CD31(+) to VE-cadherin(+) cells was identified by flow cytometry, and the ability of capillary-like tubes formation was detected by Matrigel assay after a 14-day induction. The measurement data were statistically analyzed.

RESULTSPhosphorylated ERK1/2 protein level in PDLSC was increased to 1.24±0.12 and 1.03±0.24 at 1 h and 3 h respectively, during the endothelial induction (P<0.01). The mRNA expressions of CD31 and VEGF in induced+U0126 group were decreased to 0.09±0.18 and 0.49±0.17, which were both significantly different with those in induced group (P<0.05). The proportion of CD31(+) to VE-cadherin(+) cells of induced+U0126 group were decreased to 5.22±0.85 and 3.56±0.87, which were both significantly different with those in induced group (P<0.05). In Matrigel assay, the branching points, tube number and tube length were decreased to 7.0±2.7, 33.5±6.4, and (15 951.0±758.1) pixels, which were all significantly different with those in induced group (P<0.05).

CONCLUSIONSThe endothelial differentiation of PDLSC is positively regulated by ERK signaling pathway. Inhibition of ERK1/2 phosphorylation could suppress endothelial differentiation of PDLSC.

Antigens, CD ; genetics ; metabolism ; Butadienes ; pharmacology ; Cadherins ; genetics ; metabolism ; Cell Differentiation ; Endothelial Cells ; cytology ; physiology ; Enzyme Inhibitors ; pharmacology ; Extracellular Signal-Regulated MAP Kinases ; physiology ; Fibroblast Growth Factor 2 ; pharmacology ; Humans ; Mitogen-Activated Protein Kinase 3 ; antagonists & inhibitors ; metabolism ; Nitriles ; pharmacology ; Periodontal Ligament ; cytology ; metabolism ; Phosphorylation ; Platelet Endothelial Cell Adhesion Molecule-1 ; genetics ; metabolism ; RNA, Messenger ; metabolism ; Random Allocation ; Signal Transduction ; Stem Cells ; cytology ; physiology ; Time Factors ; Vascular Endothelial Growth Factor A ; genetics ; metabolism ; pharmacology

Abnormal proliferation of vascular smooth muscle cells (VSMCs) plays an important role in several pathological processes of cardiovascular diseases. In this study, the effects of XCT790, a potent and selective inverse agonist of estrogen-related receptor alpha (ERRalpha), on rat VSMCs proliferation and related signal pathways were investigated. The proliferative activity of VSMCs was determined by CCK-8 assay. The mRNA levels of ERRalpha, PGC-1alpha, OPN and MCAD were assayed by RT-PCR. The protein levels of ERRalpha, ERK2 and p-ERK1/2 were evaluated by Western blotting. ELISA was used to assess the protein expression of VEGF. The results showed that XCT790 (5-20 micromol x L(-1)) inhibited rat VSMCs proliferation, and the expression of ERRalpha and its target genes, as well as p-ERK1/2, were also inhibited. XCT790 inhibited VSMCs proliferation in a dose-dependent manner at the dose range from 5 to 20 micromol x L(-1) and in a time-dependent manner at the dose range from 10 to 20 micromol x L(-1). These findings demonstrate that XCT790 inhibits rat VSMCs proliferation by down-regulating the gene level of ERRalpha and thus inhibiting the ERK signal pathway, suggesting that ERRalpha may be a novel potential target for therapeutic approaches to inhibit VSMCs proliferation, which plays an important role in several cardiovascular diseases.
Animals ; Cadherins ; genetics ; metabolism ; Cell Proliferation ; drug effects ; Cells, Cultured ; Cytoskeletal Proteins ; genetics ; metabolism ; Dose-Response Relationship, Drug ; GTPase-Activating Proteins ; genetics ; metabolism ; MAP Kinase Signaling System ; Male ; Muscle, Smooth, Vascular ; cytology ; Myocytes, Smooth Muscle ; cytology ; drug effects ; metabolism ; Nitriles ; administration & dosage ; pharmacology ; Nuclear Proteins ; genetics ; metabolism ; Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1-alpha ; Phosphorylation ; RNA, Messenger ; metabolism ; Rats ; Rats, Sprague-Dawley ; Receptors, Estrogen ; genetics ; metabolism ; Thiazoles ; administration & dosage ; pharmacology ; Transcription Factors ; genetics ; metabolism ; Vascular Endothelial Growth Factor A ; genetics ; metabolism

BACKGROUNDBreast cancer is one of the most common malignant female diseases worldwide. It is a significant threat to every woman's health. Vascular endothelial growth inhibitor (VEGI) is known to be abundant in endothelial cells. According to previous literature, overexpression of VEGI has been shown to inhibit tumor neovascularisation and progression in cellular and animal models, but there has been limited research on the significance of VEGI in the breast cancer.

METHODSIn our study, cell lines MDA-MB-231 were first constructed in which VEGI mediated by lentivirus over-expressed. The effects of VEGI over-expression on MDA-MB-231 cells were investigated both in vitro and in vivo. The expression of VEGI in the MDA-MB-231 cells after infection of lentivirus was analyzed using real-time PCR and Western blotting. The effect of the biological characteristics of MDA-MB-231 cells was assessed by growth, invasion, adhesion, and migration assay with subcutaneous tumor-bearing nude mice models. Then the growth curves of the subcutaneous tumors were studied. Expressions of VEGI, CD31 and CD34 in the tumors were analyzed by immunohistochemistry and apoptosis was detected by flow cytometry and immunohistochemistry.

RESULTSInfection of MDA-MB-231 cells within the lentivirus resulted in approximately a 1 000-fold increase in the expression of VEGI. As can be seen in the invasion, adhesion and migration assay, the over-expression of VEGI can inhibit the ability of MDA-MB-231 cells during migration, adhesion and invasion. The volume of the subcutaneous tumor in the over-expression group was distinctly and significantly less than that of the control groups. Immunohistochemistry analysis of the tumor biopsies clearly showed the expression of VEGI in the over-expression group increased while CD31 and CD34 decreased significantly. In vitro and in vivo, the early apoptosis rate and the apoptosis index were increased within the VEGI over-expression group as compared with the control group.

CONCLUSIONSTaken together, recombinant lentivirus that were successfully constructed, demonstrated up-regulated VEGI gene expression in breast cancer cells. Lentivirus-mediated over-expression of VEGI weakened the ability of the breast cancer cell migration, adhesion and invasion. Over-expression of VEGI diminished the tumorigenic capacity of breast cancer cells in vivo. Up-regulation of VEGI gene expression however inhibited breast cancer MDA-MB-231 cell in the early apoptosis.

Apoptosis ; genetics ; physiology ; Breast Neoplasms ; genetics ; metabolism ; pathology ; Cell Line, Tumor ; Cell Proliferation ; genetics ; physiology ; Female ; Gene Expression Regulation, Neoplastic ; genetics ; physiology ; Genetic Vectors ; genetics ; Humans ; Lentivirus ; genetics ; Vascular Endothelial Growth Factors ; genetics ; metabolism

BACKGROUND/AIMS: Renal hypoxia is involved in the pathogenesis of diabetic nephropathy. Pentoxifyllin (PTX), a nonselective phosphodiesterase inhibitor, is used to attenuate peripheral vascular diseases. To determine whether PTX can improve renal hypoxia, we investigated its effect in the streptozocin (STZ)-induced diabetic kidney. METHODS: PTX (40 mg/kg, PO) was administered to STZ-induced diabetic rats for 8 weeks. To determine tissue hypoxia, we examined hypoxic inducible factor-1alpha (HIF-1alpha), heme oxygenase-1 (HO-1), vascular endothelial growth factor (VEGF), and glucose transporter-1 (GLUT-1) levels. We also tested the effect of PTX on HIF-1alpha in renal tubule cells. RESULTS: PTX reduced the increased protein creatinine ratio in diabetic rats at 8 weeks. HIF-1alpha, VEGF, and GLUT-1 mRNA expression increased significantly, and the expression of HO-1 also tended to increase in diabetic rats. PTX significantly decreased mRNA expression of HIF-1alpha and VEGF at 4 and 8 weeks, and decreased HO-1 and GLUT-1 at 4 weeks. The expression of HIF-1alpha protein was significantly increased at 4 and 8 weeks in tubules in the diabetic rat kidney. PTX tended to decrease HIF-1alpha protein expression at 8 weeks. To examine whether PTX had a direct effect on renal tubules, normal rat kidney cells were stimulated with CoCl2 (100 microM), which enhanced HIF-1alpha mRNA and protein levels under low glucose conditions (5.5 mM). Their expressions were similar even after high glucose (30 mM) treatment. PTX had no effect on HIF-1alpha expression. CONCLUSIONS: PTX attenuates tubular hypoxia in the diabetic kidney.
Animals ; Anoxia/*drug therapy/enzymology/etiology/genetics ; Cell Line ; Cobalt/pharmacology ; Diabetes Mellitus, Experimental/*complications ; Diabetic Nephropathies/*drug therapy/enzymology/etiology/genetics ; Disease Models, Animal ; Gene Expression Regulation/drug effects ; Glucose/metabolism ; Glucose Transporter Type 1/genetics ; Heme Oxygenase (Decyclizing)/genetics/metabolism ; Hypoxia-Inducible Factor 1, alpha Subunit/genetics/metabolism ; Kidney Tubules/*drug effects/enzymology ; Male ; Pentoxifylline/*pharmacology ; Phosphodiesterase Inhibitors/*pharmacology ; RNA, Messenger/metabolism ; Rats ; Rats, Sprague-Dawley ; Streptozocin ; Time Factors ; Vascular Endothelial Growth Factor A/genetics

Previous studies suggested that polymorphisms of proinflammatory cytokine genes are important host genetic factors in Helicobacter pylori infection. The present study evaluated whether IL-8-251 polymorphism affected H. pylori eradication rate and to investigate the effect of H. pylori eradication on angiogenesis and the inflammatory process according to the IL-8-251 polymorphism. A total of 250 H. pylori-positive patients treated by endoscopic resection of the gastric neoplasm were classified into 3 groups (134 H. pylori-eradicated group, 19 H. pylori-eradication failure group, and 97 H. pylori-infected group). H. pylori status, histology, and angiogenic factor levels were evaluated at baseline, 6 months, and 18 months. H. pylori eradication rate was 92.9% in AA genotype, 85.7% in AT genotype and 88.4% in TT genotype (P value = 0.731). Elevated IL-8 and matrix metalloproteinase-9 concentrations in H. pylori-infected gastric mucosa were reversible by successful eradication of H. pylori, independent of the IL-8-251 polymorphism. It is suggested that elevated IL-8 and MMP-9 concentrations in H. pylori-infected gastric mucosa are altered significantly after successful eradication and these conditions continue for 18 months. However, IL-8-251 polymorphism does not affect H. pylori eradication rate and the sequential changes of related angiogenic factors after H. pylori eradication in Koreans.
Aged ; Alleles ; Angiopoietin-1/analysis ; Anti-Bacterial Agents/therapeutic use ; Anti-Inflammatory Agents, Non-Steroidal/therapeutic use ; Asian Continental Ancestry Group/*genetics ; Female ; Gastric Mucosa/metabolism/pathology ; Genotype ; Helicobacter Infections/*drug therapy ; *Helicobacter pylori ; Humans ; Interleukin-8/analysis/*genetics ; Male ; Matrix Metalloproteinase 9/analysis ; Middle Aged ; *Polymorphism, Single Nucleotide ; Proton Pump Inhibitors/therapeutic use ; Republic of Korea ; Retrospective Studies ; Stomach Neoplasms/pathology/surgery ; Time Factors ; Vascular Endothelial Growth Factor A/analysis

OBJECTIVETo investigate the significance of Tiam1 in invasion and metastasis of breast carcinoma and its mechanisms.

METHODSImmunohistochemistry was used to detect Tiam1 expression in tumor tissue of 126 breast carcinomas. Tiam1 was silenced by siRNA in breast carcinoma cell line MDA-MB-435, then the expressions of phosphor-ERK 1, ERK 2 and VEGF were detected, and electrophoretic mobility shift assay (EMSA) was used to examine the transcription activiy of AP-1.

RESULTSThere was a significant relationship between Tiam1 expression and lymph node metastasis (P < 0.05). Furthermore, after silencing of Tiam1, the expressions of phosphor-ERK 1, ERK 2 and VEGF were decreased, and the transcription activity of AP-1 was down-regulated in the MDA-MB-435 cells.

CONCLUSIONTiam1 is closely related with invasion and metastasis of breast carcinoma, and the cascade Tiam1 through ERK, AP-1 and VEGF pathways may play an important role in enhancing angiogenesis, therefore, to promote invasion and metastasis of breast carcinoma.

Breast Neoplasms ; metabolism ; pathology ; Cell Line, Tumor ; Female ; Gene Expression Regulation, Neoplastic ; Gene Silencing ; Guanine Nucleotide Exchange Factors ; genetics ; metabolism ; Humans ; Lymphatic Metastasis ; Mitogen-Activated Protein Kinase 1 ; metabolism ; Mitogen-Activated Protein Kinase 3 ; metabolism ; Neoplasm Invasiveness ; RNA, Messenger ; metabolism ; RNA, Small Interfering ; genetics ; Signal Transduction ; T-Lymphoma Invasion and Metastasis-inducing Protein 1 ; Transcription Factor AP-1 ; metabolism ; Vascular Endothelial Growth Factor A ; metabolism

OBJECTIVETo construct the zinc finger protein-activating transcription factor (ZFP-ATF) plasmid and evaluate its efficacy in inducing vascular endothelial growth factor (VEGF) expression in EY.HY926 endothelial cells.

METHODSFirstly, we constructed the ZFP-ATF plasmid, then testified the quantity of VEGF protein in EY.HY926 endothelial cells after transfected with ZFP-ATP plasmid by Western blot, finally, we used the RT-PCR to testify whether the ZFP-ATF can stimulate expression of VEGF splice variants.

RESULTSThe ZFP-ATF DNA sequences were located the multiclone sites of PVAX1 vector between the site of BamH1and Xhol.Western blot result showed VEGF expression in EY.HY926 endothelial cells transfected with ZFP-ATF plasmid was significantly higher than that in cells transfected with VEGF165 (19.95±3.95 vs.12.15±1.55 μg÷μL, P<0.01).RT-PCR result showed VEGF-A mRNA expression level induced by ZFP-ATF was high than that induced by VEGF165.

CONCLUSIONZFP-ATF can up-regulate the VEGF-A expression in comparison with VEGF165, which might have beneficial effects in angiogenesis process.

Activating Transcription Factors ; physiology ; Amino Acid Sequence ; Base Sequence ; Cells, Cultured ; Endothelial Cells ; metabolism ; Humans ; Molecular Sequence Data ; Neovascularization, Physiologic ; Plasmids ; Up-Regulation ; Vascular Endothelial Growth Factor A ; genetics ; Zinc Fingers ; physiology

OBJECTIVETo investigate the effect of cyclopamine on metastatic ability of human esophageal cancer EC109 cells and explore the possible mechanism.

METHODSTranswell chamber assay and angiogenesis assay were used to examine the metastatic ability, invasiveness and angiogenesis of EC109 cells treated with cyclopamine for 48 h. The expression of Gli-1 mRNA was detected using RT-PCR, and Western blotting was used to examine the protein expressions of Gli-1, matrix metalloproteinase-9 (MMP-9) and vascular endothelial growth factor (VEGF).

RESULTSInhibition of the hedgehog signaling pathway by cyclopamine suppressed the migration, invasion, and angiogenesis of EC109 cells. Cyclopamine treatment significantly lowered the expression of Gli-1 mRNA (P<0.05) and the protein expressions of Gli-1, MMP-9 and VEGF (P<0.05).

CONCLUSIONCyclopamine can significantly inhibit the metastatic capacity of EC109 cells possibly by down-regulating MMP-9 and VEGF expression as a result of Gli-1 inhibition.

Cell Line, Tumor ; Esophageal Neoplasms ; metabolism ; pathology ; Gene Expression Regulation, Neoplastic ; Humans ; Matrix Metalloproteinase 9 ; metabolism ; Neoplasm Metastasis ; RNA, Messenger ; genetics ; Signal Transduction ; drug effects ; Transcription Factors ; metabolism ; Vascular Endothelial Growth Factor A ; metabolism ; Veratrum Alkaloids ; pharmacology ; Zinc Finger Protein GLI1

OBJECTIVETo observe the effects of the three-period treatment theory of bone fracture in TCM (Traditional Chinese Medicine) on VEGF and VEGF mRNA expression in the issues of outer periosteum, endosteum and bone marrow of rabbits, and to explore the rationality of phasing method in TCM in treating fracture.

METHODS3 mm bone defection were made at lower one third part of both radius in 140 male healthy rabbits. The rabbits were randomly divided into four groups, including three-period treatment group (TTG), one-period treatment group(OTG), positive medicine treatment group(PTG) and model control group (MCG). The rabbits in TG were treated with three-period treatment, rabbits in OTG were treated with one-period treatment, rabbits in PTG were fed by Guzhe-Cuoshangsan (a Chinese patent medicine which was used to treat bone fracture), rabbits in model control group were given no prescription or drug but distilled water as same dose as that of other groups. At day 3, 6, 9, 14, 28, 42 and 56, five rabbits from every group were randomly selected and were killed by aeroembolism. The left radiuses were taken out as the research object. Immunohistochemistry stain and in situ hybridization stain were performed to examinate the VEGF and VEGF mRNA expression in the outer periosteum, endosteum and bone marrow.

RESULTSThe VEGF and VEGF mRNA expression of all TCM treatment groups were enhanced in the outer periosteum, endosteum and bone marrow at different time points in fracture healing. The VEGF and VEGF mRNA expression in the three tissues of TTG had the tendency of higher than that of the other groups at the most time points after operation.

CONCLUSIONTreating fracture in stages has more predominant effect on the expression of VEGF and VEGF mRNA in the outer periosteum, endosteum and bone marrow than that of treating fracture with single prescription or drug.

Animals ; Bone Marrow ; metabolism ; Fractures, Bone ; metabolism ; therapy ; Male ; Medicine, Chinese Traditional ; Periosteum ; metabolism ; RNA, Messenger ; analysis ; Rabbits ; Vascular Endothelial Growth Factors ; analysis ; genetics