OBJECTIVETo explore the effects of angiopoietins (Ang-1 and Ang-2) and Tie-2 expression on microvessel density (MVD) in gastric cancers.

METHODSBy using semiquantitative RT-PCR, immunohistochemistry and image analysis system, the expression of Ang-1, Ang-2, Tie-2 mRNA and their proteins were detected in 68 primary gastric cancers and their adjacent normal tissues. Microvessel density (MVD) was figured out based on CD34 immunohistochemical staining.

RESULTSThe expression of all Ang-1, Ang -2, Tie-2 mRNA and their proteins was detected in gastric cancers and their paired adjacent gastric mucosa tissues. A negative correlation between Ang-1 protein, Tie-2 mRNA and MVD in gastric cancers was observed (r = -0.440, r = -0.267; P < 0.05), while the relation between Ang-2 mRNA and its protein, Ang-2/Ang-1 protein ratio with MVD were positive (r = 0.319, r = 0.729, r = 0.739; P < 0.05). It was found that MVD in groups with Ang-2 mRNA T/N ratio over 1.2 (the ratio of Ang-2 mRNA in gastric cancers and its adjacent normal mucosa) was higher than that in those with a ratio under 1.2, revealed by analysing the effects of Ang-1 and Ang-2 mRNA T/N ratio on MVD in gastric cancers.

CONCLUSIONAng-1 activates Tie-2 receptor, whereas Ang-2 antagonizes Ang-1 in the angiogenesis, and the Ang-2/Ang-1 ratio determines angiogenesis and tumor growth in gastric cancers. When the expression of Ang-2 is high and Ang-1 is low, the angiogenesis in gastric cancers is promoted, otherwise oppositely. The role of Ang-2 is dominant in the effect of Angs and their receptor on angiogenesis in gastric cancers.

Angiopoietin-1 ; biosynthesis ; genetics ; Angiopoietin-2 ; biosynthesis ; genetics ; Female ; Humans ; Male ; Microcirculation ; pathology ; Middle Aged ; Neoplasm Staging ; Neovascularization, Pathologic ; etiology ; RNA, Messenger ; biosynthesis ; genetics ; Receptor, TIE-2 ; biosynthesis ; genetics ; Stomach Neoplasms ; blood supply ; metabolism ; pathology

OBJECTIVE: To investigate the relationship between the expression of Ang2, Tie2 and the angiogenesis of hepatocellular carcinoma in rats. METHODS: Thirty-eight healthy male rats were randomly divided into 3 groups: 5 rats in the control group; 25 rats in the experimental group were equally divided into 5-day, 10-day, 15-day, 20-day, and 25-day groups; the other 8 rats were used as the supplement of the experimental group. An allogenic transplanted rat model of CBRH-7919 hepatocellular carcinoma in situ was established by immunosuppression. The expressions of Ang2 and Tie2 were detected by immunohistochemical staining in cancerous tissues of different developmental stages and liver tissues of the control group. At the same time, microvessel density was determined by anti-CD31 immunohistochemical staining. RESULTS: CBRH-7919 hepatocellular carcinoma models were successfully set up in 24 rats. The expression level of Ang2 and Tie2 in cancerous tissues was much higher than that of liver tissues of the control group (P <0.05). The overexpression of Ang2 was pristine and continuous in different developmental stages. The expressions of Ang2 and Tie2 positively correlated with microvessal density in hepatocellular carcinoma (P<0.05). CONCLUSION The up-regulation of Ang2 and Tie2 may play important roles in the angiogenesis of hepatocellular carcinoma. Ang2 may participate in the start of angiogenesis of hepatocellular carcinoma.
Angiopoietin-2 ; biosynthesis ; genetics ; Animals ; Liver Neoplasms, Experimental ; blood supply ; metabolism ; Male ; Neovascularization, Pathologic ; RNA, Messenger ; genetics ; Random Allocation ; Rats ; Rats, Wistar ; Receptor, TIE-2 ; biosynthesis ; genetics

OBJECTIVETo investigate the expression of angiopoietin (Ang)-1 and Ang-2 in colorectal tumors and its relations to microvessel density (MVD) in tumor tissue.

METHODSAng-1, Ang-2 and factor VIII-related antigen were stained immunohistochemically in 91 cases of primary colorectal adenocarcinoma, 20 cases of colorectal adenoma and 24 cases of normal colorectal mucosal tissue, and MVD was also assayed in above tissue specimens.

RESULT(1) A significantly higher Ang-1 (7.07+/-2.00) was observed in normal tissue compared with 1.75 +/-1.98 in the adenoma and 1.40 +/- 1.22 in the adenocarcinoma (P<0.01). (2) Ang-2 protein positive rate in adenocarcinoma was significantly higher than that in normal tissue and adenoma (P<0.01). The expression of Ang-2 in adenocarcinoma was closely associated with poor differentiation and vessel invasion. (3) There were significant correlations between Ang-1 and Ang-2 (r=-0.338, P<0.01), Ang-1 and MVD (r=-0.388, P<0.01), Ang-2 and MVD (r=0.594, P<0.01) in the 135 cases.

CONCLUSIONThe overexpression of Ang-2 may play an important role in angiogenesis of colorectal adenocarcinoma. It can be regarded as an index for malignancy and prognosis in colorectal adenocarcinoma.

Adenocarcinoma ; blood supply ; metabolism ; Adult ; Aged ; Aged, 80 and over ; Angiopoietin-1 ; biosynthesis ; genetics ; Angiopoietin-2 ; biosynthesis ; genetics ; Biomarkers, Tumor ; Capillaries ; pathology ; Colorectal Neoplasms ; blood supply ; metabolism ; Female ; Humans ; Male ; Middle Aged ; Prognosis ; von Willebrand Factor ; biosynthesis ; genetics

Angiogenesis, formation of new microvessels providing oxygen and nutrient supply, is essential for tumor growth. It is dependent on the production of angiogenic growth factors by tumor cells. Angiopoietin 1 (Ang-1) and 2 (Ang-2) and their common receptor, Tie2, are thought to be critical regulators of tumor angiogenesis. We examined expression of Ang-1, Ang-2, and their common receptor Tie2 mRNAs and proteins in gastric cancers using in situ hybridization and immunohistochemistry. We also investigated the relationship between their expression and differentiation of cancer cells, lymph node metastasis, tumor size, depth of cancer cell invasion, TNM staging and microvessel density (MVD). The expression of Ang-1, Ang-2, and Tie2 mRNA in cancer cells significantly correlated with the MVD (p<0.001, <0.001 and =0.019, respectively). Ang-1 and Tie2 positivity correlated with advanced gastric cancers (p<0.05) and larger cancers had higher positive rates of Ang-1, Ang-2, and Tie2 mRNA expression (p<0.001, =0.010 and =0.039, respectively). Significant positive correlations were also found between mRNA expression of Tie2 and those of Ang-1 and Ang-2 (p<0.01 and <0.001, respectively). These findings indicate that the expression of Ang-1 and Ang-2 is important for tumor angiogenesis, and suggest a possible role of autocrine/paracrine function of angiopoietin/Tie2 system in gastric cancer progression.
Stomach Neoplasms/blood supply/*genetics/*metabolism/pathology ; Receptor, TIE-2/*genetics/*metabolism ; RNA, Neoplasm/genetics/metabolism ; RNA, Messenger/genetics/metabolism ; Neovascularization, Pathologic ; Middle Aged ; Male ; In Situ Hybridization ; Immunohistochemistry ; Humans ; Gene Expression ; Female ; Carcinoma, Signet Ring Cell/blood supply/genetics/metabolism/pathology ; Angiopoietin-2/*genetics/*metabolism ; Angiopoietin-1/*genetics/*metabolism ; Aged ; Adult ; Adenocarcinoma/blood supply/genetics/metabolism/pathology

bThis study explored whether the transplantation of modified marrow stromal cells (MSCs) has angiogenic effects in a left middle cerebral artery occlusion infarction/reperfusion (MCAO I/R) rat model and preliminarily examined the mechanism of angiogenesis following cerebral infarction. MSCs were isolated by using a direct adherent method and cultured. Vascular endothelial growth factor (VEGF) was transfected into MSCs by employing the liposome transfection. The transfection efficiency was measured by the optical density method. The protein expression of VEGF gene before and after transfection was measured by Western blotting. SD rat model of transient occlusion of the left middle cerebral artery was established by using an approach of intra-luminal occlusion. Tetrazolium (TTC) and HE staining were performed to observe the cerebral infarction. ELISAs were used to measure the levels of VEGF in the rat cerebral tissues. The expression patterns of angiopoietin-2 (Ang-2) and CD34 in cells surrounding the area of infarction were immunohistochemistrically observed. Ang-2 protein expression in the tissue surrounding the area of infarction was measured by Western blotting. VEGF expression in the MSCs increased after transfection at a rate of approximately 28%±3.4%. ELISA showed that the expression of VEGF in the cerebral tissue was significantly increased after induction of infarction, peaking on the 4th day and decreasing to the levels of the sham surgery group (normal) within 7 to 10 days. The VEGF level was significantly higher at each time point in the VEGF-MSC and MSC groups compared to the model group. Moreover, the VEGF level was higher in the VEGF-MSC group than in the MSC group and stayed relatively high until the 10th day. The immunohistochemical results showed that 10 days after the infarction, the number of Ang-2 and CD34-expressing cells in the area surrounding the infarction was significantly higher in the VEGF-MSC group and the MSC group compared to the model group. Moreover, the VEGF level was higher in the VEGF-MSC group than the MSC group. A similar trend in Ang-2 protein expression was revealed by Western blotting. In the MCAO rat model transfected with modified MSCs over-expressing VEGF, compared to the MSC transplantation group, the concentration of VEGF was significantly increased in the brain tissue after cerebral infarction. In addition, the level of Ang-2 was up-regulated, with angiogenesis promoted, the blood supply to the areas surrounding the cerebral infarction increased, and neurological function improved. We are led to speculate that the synergistic effects of VEGF and Ang-2 may be responsible for the angiogenesis following cerebral infarction.
Angiopoietin-2 ; genetics ; metabolism ; Animals ; Bone Marrow ; metabolism ; pathology ; Cerebral Infarction ; genetics ; metabolism ; pathology ; Male ; Neovascularization, Pathologic ; genetics ; pathology ; Rats ; Rats, Sprague-Dawley ; Stromal Cells ; metabolism ; pathology ; Vascular Endothelial Growth Factor A ; genetics ; metabolism

AIM: Microvasculature and microenvironment play important roles in proliferation, invasion, metastasis and prognosis in non-small cell lung cancer (NSCLC), which might be altered by many anti-angiogenic drugs. Epigallocatechin-3-gallate (EGCG), a natural anti-angiogenesis agent refined from green tea, was defined to have multiple effects on angiogenesis factors, such as endothelial growth factor (VEGF), platelet-derived growth factor (PDGF) and angiopoietins (ANGs). Hypothesizing that EGCG might regulate microvasculature and microenvironment in NSCLC, the effects of EGCG on microvessel density (MVD), expression of Ang-1 and Ang-2, interstitial fluid pressure (IFP), tumor hypoxia, and chemotherapy sensitivity were examined. METHODS AND RESULTS: EGCG treatment of A549 cells in mice bearing xenografts in vivo led to a significant decrease of MVD detected by CD31, and of Ang-2 expression detected by quantum dots double-label immunofluorescence assessment, while Ang-1 decreased with no significance. Decreased IFP was measured by the Wink-in-needle method, while hypoxia was assessed by polarographic electrode and pimonidazole (PIMO) immunohistochemistry. Assuming that these changes would increase response to chemotherapy, tumor growth studies were p[erformed in nude mice with xenografts, which were then treated with EGCG and the chemotherapeutic agent cisplatin. EGCG therapy combined with cisplatin led to synergistic inhibition of tumor growth, compared with administration of each treatment separately (P < 0.001). According to linear regression analysis, IFP was positively correlated with PIMO staining (R(2) = 0.618, P = 0.002), Ang-2 was correlated with MVD (R(2) = 0.423, P = 0.022), IFP (R(2) = 0.663, P = 0.01) and PIMO staining (R(2) = 0.694, P = 0.01). CONCLUSION IFP and delivery of oxygen might be improved by rebalance of Ang-1/Ang-2 under the treatment of EGCG in NSCLC, which also acts as a sensitizer of chemotherapy. These studies established a new mechanism for using EGCG as an adjuvant chemotherapy agent through modifying microvasculature and microenvironment.
Angiogenesis Inhibitors ; administration & dosage ; Angiopoietin-1 ; genetics ; metabolism ; Angiopoietin-2 ; genetics ; metabolism ; Animals ; Antineoplastic Agents ; therapeutic use ; Carcinoma, Non-Small-Cell Lung ; drug therapy ; genetics ; metabolism ; Catechin ; administration & dosage ; analogs & derivatives ; Chemotherapy, Adjuvant ; Cisplatin ; therapeutic use ; Drug Therapy, Combination ; Extracellular Fluid ; drug effects ; metabolism ; Female ; Humans ; Lung Neoplasms ; drug therapy ; genetics ; metabolism ; Mice ; Mice, Inbred BALB C ; Mice, Nude ; Oxygen ; metabolism

OBJECTIVETo explore the effect of Ang-2 on angiogenesis in gastric cancer.

METHODSThe expression of Ang-2 mRNA was analyzed by RT-PCR and the expression of VEGF and CD34 was detected by immunohistochemistry in 36 cases of gastric cancer tissues and their paired adjacent gastric mucosa.

RESULTSThe expression of Ang-2 mRNA was found both in gastric cancer and their paired adjacent gastric mucosa; the correlationship between the general expression levels of Ang-2 mRNA and microvessel density (MVD) in gastric cancer tissues was not found. However, in 27 cases whose Ang-2 mRNA expression levels in cancer tissues were lower than those in adjacent gastric mucosa. A significant positive correlation between the expression level of Ang-2 mRNA and MVD in the tumor tissues was found (r = 0.411, P < 0.05). In these 27 cases, the MVD in the gastric cancer tissues with positive VEGF expression (45.45 +/- 10.30) was higher than that with negative VEGF expression (30.15 +/- 8.69, P < 0.05), whereas in the other 9 cases whose expression levels of Ang-2 mRNA in cancer tissues were higher than those in adjacent gastric mucosa, a significant negative correlation between expression level of Ang-2 mRNA and MVD in the tumor tissues (r = -0.758, P < 0.05), but without correlation between the MVD and VEGF.

CONCLUSIONUnder the conditions that the expression of Ang-2 mRNA in cancer tissues was lower than that in adjacent gastric mucosa, VEGF could promote the sprouting of new vessels along with Ang-2 upregulation. But under the conditions that the expression of Ang-2 mRNA in cancer tissues was higher than that in adjacent gastric mucosa, Ang-2 inhibited angiogenesis. Angiopoietin-2 may play a dual effect on angiogenesis in gastric cancer.

Angiopoietin-2 ; genetics ; physiology ; Female ; Gastric Mucosa ; metabolism ; Humans ; Immunohistochemistry ; Male ; Middle Aged ; Neovascularization, Pathologic ; etiology ; RNA, Messenger ; analysis ; Stomach Neoplasms ; blood supply ; Vascular Endothelial Growth Factor A ; analysis

OBJECTIVETo investigate the mechanisms of Buyang Huanwu Decoction (BYHWD) by observing its effects on expressions of angiopoietin-1 (Ang-1) and the endothelial-specific receptor tyrosine kinase (Tie-2) mRNA in damaged region of rats' brain after intracerebral hemorrhage (ICH).

METHODSOne hundred and sixty Sprague-Dawley rats were randomly divided into four groups, 10 in the normal control group, 60 in the sham-operative group, 60 in the ICH model group, and 30 in the BYHWD-treated group. The ICH model was established by injecting collagenase type VII 0.5 U stereotaxically into right globus pallidus. Animals in the BYHWD-treated group were administered orally with BYHWD, while animals in the sham-operative group and the ICH model group were administered orally with equal volume distilled water, and those in the normal control group drank water freely. The positional variations of the expression of Ang-1 and Tie-2 in the sham-operative group and the model group were assayed by immunohistochemistry on dayl, 4, 7, 14, 21 and 28 after modeling, in the meantime, the dynamic changes of Ang-1 and Tie-2 mRNA expressions in all groups were assayed by reverse transcription-polymerase chain reaction (RT-PCR).

RESULTSNo significant expression of Ang-1 and Tie-2 in brain of rats in the normal or the sham-operative group was found during the experiment. In the model group, the Ang-1 and Tie-2 positive micrangio-segments appeared at the edge of clot on day 1 to day 4, they gradually penetrated to hematoma area from day 7; with Ang-1 and Tie-2 mRNA expressed from day 1, but very weak until day 4, showing no significant difference to that on day 1; thereafter, they increased gradually, and reached the peak on day 28 (P <0.05). While the two expressions in the BYHWD treated group reached the peak on day 21, and from day 7 to day 28, they were all significantly higher than those in ICH model group at the corresponding time points (P <0.01).

CONCLUSIONBYHWD can promote the up-regulation of Ang-1 and Tie-2mRNA expressions in brain of intracerebral hemorrhagic rats, which might accelerate the angiogenesis in the reconstruction of microvascular network in the damaged zone, and thus facilitating the repairing of damaged tissue.

Angiopoietin-1 ; genetics ; metabolism ; Animals ; Brain ; drug effects ; metabolism ; Cerebral Hemorrhage ; drug therapy ; genetics ; metabolism ; Disease Models, Animal ; Drugs, Chinese Herbal ; administration & dosage ; Female ; Gene Expression ; drug effects ; Humans ; Male ; Rats ; Rats, Sprague-Dawley ; Receptor, TIE-2 ; genetics ; metabolism

OBJECTIVETo observe the effect of Taohong Siwu decoction (THSWD) on micro-vascular density (MVD) in rat uterus, the content of angiopoietin-1 (Ang-1) and angiopoietin-2 (Ang-2) in serum, and the expression of tyrosine kinasa receptor (Tie-2) in uterus.

METHODEarly pregnancy rats were intragastrically administrated with misoprostol (100 microg x kg(-1)) and mifepristong (8.3 mg x kg(-1)) to established the incomplete-abortion model. The incomplete-abortion rats were randomly divided into the model group (the same volume of distilled water), the positive control group (at the daily dose of 4.3 g x kg(-1) Motherwort Particles), and THSWD-treated groups (at the daily dose of 18.0, 9.0 and 4.5 g x kg(-1)). Pregnant rats were taken as the control group (the same volume of distilled water). After the successive oral administration for 7 days, blood was collected from aorta abdominalis, and rat uterine tissues were collected. The content of serum Ang-1 and Ang-2 were detected by ELISA; And the levels of Tie-2 and MVD in uterine tissues were detected by SP immunohistochemistry.

RESULTTHSWD remarkably increased the levels of MVD in uterus of medicine-induced abortion rats, the content of Ang-1 and Ang-2 in serum, and the expression of Tie-2 in uterine tissues.

CONCLUSIONTHSWD has the effect in markedly promoting angiogenesis in incomplete-abortion rats. Its mechanism may be related to the regulation of concentrations of Ang-1 and Ang-2 in serum and Tie-2 in uterine tissues.

Abortion, Incomplete ; blood ; drug therapy ; genetics ; Angiopoietin-1 ; blood ; genetics ; Angiopoietin-2 ; blood ; genetics ; Animals ; Drugs, Chinese Herbal ; therapeutic use ; Female ; Gene Expression ; drug effects ; Humans ; Pregnancy ; Rats ; Rats, Sprague-Dawley ; Receptor, TIE-2 ; genetics ; metabolism ; Uterus ; blood supply ; drug effects ; metabolism

OBJECTIVETo examine the temporal and spatial expression of vascular endothelial growth factor (VEGF) and angiopoietins (Ang) in rat brain after cerebral ischemia, and to elucidate the roles they played in angiogenesis and vascular permeability.

METHODSRats were subjected to either middle cerebral artery occlusion (MCAO) or sham operation. Reverse transcriptase-polymerase chain reaction, Western blotting, and immunohistochemistry were used to detect the expression of VEGF, Ang-1 and Ang-2 at different time points after ischemia. CD31 was used to label endothelial cells after MCAO. Vascular permeability was determined by Evans blue.

RESULTSVEGF was markedly increased at 2 h, had an initial peak at 12 h (0.7249 ± 0.1933, P < 0.01), and a second peak at 7 days (0.5264 ± 0.1519, P < 0.01). Ang-2 mRNA and protein significantly increased after MCAO, both of them peaked at 12 h (0.6747 ± 0.2416, P < 0.01; 1.1197 ± 0.1780, P < 0.01). In contrast, Ang-1 mRNA and protein gradually decreased after MCAO, respectively reaching a minimum at 3 d (0.3220 ± 0.1427, P < 0.01) and 1 d (0.1298 ± 0.0293, P < 0.01). Changes in the expression of these factors correlated with the progress of angiogenesis and vascular permeability. Evans blue test revealed that the vascular permeability gradually increased, and peaked at day 1 after ischemia [(6.219 ± 0.887) µg/g, P < 0.01].

CONCLUSIONDynamic temporal changes in VEGF, Ang-1 and Ang-2 expression stimulate the cerebral angiogenesis after focal cerebral ischemia.

Angiopoietin-1 ; genetics ; metabolism ; Angiopoietin-2 ; genetics ; metabolism ; Animals ; Blotting, Western ; Capillary Permeability ; Immunohistochemistry ; Infarction, Middle Cerebral Artery ; metabolism ; pathology ; physiopathology ; Male ; Neovascularization, Physiologic ; RNA, Messenger ; metabolism ; Random Allocation ; Rats ; Rats, Sprague-Dawley ; Reverse Transcriptase Polymerase Chain Reaction ; Vascular Endothelial Growth Factor A ; genetics ; metabolism