Clinicopathologic significance of expression of nuclear factor-κB RelA and its target gene products in gastric cancer patients

AIM: To assess the prognostic significance of nuclear factor-κB (NF-κB) and its target genes in gastric cancer.

METHODS: The tumor tissues of 115 patients with gastric cancer were immunohistochemically evaluated using monoclonal antibodies against NF-κB RelA. Preoperative serum levels of vascular endothelial growth factor (VEGF), interleukin-6 (IL-6) were assessed via enzyme-linked immuno-sorbent assay. C-reactive protein (CRP) and serum amyloid A (SAA) were measured via immunotrubidimetry.

RESULTS: Positive rate of NF-κB RelA was 42.6%. NF-κB RelA expression in tumor tissues was also related to serum levels of IL-6 (P = 0.044) and CRP (P = 0.010). IL-6, SAA, CRP were related to depth of invasion, VEGF and SAA were correlated with lymph node metastasis. IL-6, VEGF, SAA and CRP were related to the stage. Univariate analysis demonstrated that immunostaining of NF-κB RelA, levels of IL-6, VEGF, SAA were significantly related with both disease free survival and overall survival (OS). Multivariate analysis verified that NF-κB RelA [hazard ratio (HR): 3.40, P = 0.024] and SAA (HR: 3.39, P = 0.045) were independently associated with OS.

CONCLUSION: Increased expression of NF-κB RelA and high levels of serum SAA were associated with poor OS in gastric cancer patients.

MSCs transfected with hepatocyte growth factor or vascular endothelial growth factor improve cardiac function in the infarcted porcine heart by increasing angiogenesis and reducing fibrosis

BACKGROUND

Cell transplantation and gene therapy have been demonstrated to have beneficial effects after a myocardial infarction (MI). Here, we used a large animal model of MI to investigate the beneficial effects of mesenchymal stem cells (MSCs) transfected with hepatocyte growth factor (HGF) or vascular endothelial growth factor (VEGF) genes.

METHODS

A porcine MI model was created by balloon occlusion of the distal left anterior descending artery for 90 min followed by reperfusion. At 1 week after MI, the pigs were infused via the coronary vein with saline (n=8), MSCs + AdNull(n=8), MSC+VEGF(n=10), or MSC+HGF(n=10). Cardiac function and myocardial perfusion were evaluated by using echocardiography and gated cardiac perfusion imaging before and 4 weeks after transplantation. Morphometric and histological analyses were performed.

RESULTS

All cell-implanted groups had better cardiac function than the saline control group. There were further functional improvements in the MSC+HGF group, accompanied by smaller infarct sizes, increased cell survival, and less collagen deposition. Blood vessel densities in the damaged area and cardiac perfusion were significantly greater in the MSC+AdNull group than in the saline control group, and further increased in the MSC+VEGF/HGF groups. Tissue fibrosis was significantly less extensive in the MSC and MSC+VEGF groups than in the saline control group and was most reduced in the MSC+HGF group.

CONCLUSION

MSCs (alone or transfected with VEGF/HGF) delivered into the infarcted porcine heart via the coronary vein improved cardiac function and perfusion, probably by increasing angiogenesis and reducing fibrosis. MSC+HGF was superior to MSC+VEGF, possibly owing to its enhanced antifibrotic effect.

Serial plasma levels of angiogenic factors in patients with ST-segment elevation myocardial infarction undergoing primary percutaneous coronary intervention

BACKGROUND AND OBJECTIVES

Patients with acute myocardial infarction show varying degrees of collateral development. However, the relationships between angiogenic factors and degree of collaterals are not well known.

SUBJECTS AND METHODS

Fifty-nine patients (mean age, 59±10 years) with ST-segment elevation myocardial infarction (STEMI) underwent primary percutaneous coronary intervention (PCI). Patients were divided into one of 2 groups: group I (Rentrop collateral grade 0/1, n=34) or group II (grade 2/3, n=25). Plasma levels of vascular endothelial growth factor (VEGF), soluble VEGF receptor (sFlt-1), angiopoietin (Ang)-2, and soluble Tie-2 at baseline, 24 and 48 hours after PCI were measured.

RESULTS

There were fewer diabetic patients and higher incidence of previous angina and multi-vessel disease in group II. Group II had a lower left ventricular ejection fraction and a trend toward longer pain-to-balloon time. Plasma levels of Ang-2, sFlt-1 were elevated prior to primary PCI and decreased after PCI, whereas plasma level of VEGF was relatively low initially, however rose after PCI. sTie-2 levels showed no significant interval change in group I, but decreased over time in group II. VEGF, sFlt-1, and Tie-2 levels did not differ between the groups at each time point. However, plasma levels of Ang-2 were higher in group I than in group II at baseline and at 48 hours.

CONCLUSION

Presence of collaterals in STEMI patients undergoing primary PCI was associated with lesser rise in Ang-2 plasma level. VEGF showed a delayed response to acute ischemia compared to Ang-2. Clinical implications of our findings need to be investigated in further studies.

Importance of Serum Copper and Vascular Endothelial Growth Factor (VEGF-A) Levels in Postmenopausal Bleeding

The main aim of this study is association of serum copper and vascular endothelial growth factor (VEGF-A) in postmenopausal bleeding (PMB) patients. Blood samples were collected from female patients suffering with postmenopausal bleeding (n = 50) as well as healthy females as controls (n = 50). Serum copper levels were estimated by spectrophotometric method and serum VEGF-A by ELISA technique and compared with ultrasonographic measurement of endometrial thickness in both patients and controls. A significant increase in serum copper levels and an almost twofold increase in serum VEGF-A was observed in DUB patients when compared with controls. Correlation (r) between serum VEGF-A levels and endometrial thickness was 0.96. Odds ratio for copper, VEGF-A and combination of copper and VEGF-A was 0.0426, 0.0947 and 0.0313 respectively, in all these cases odds ratio was <1. The abnormal angiogenesis in PMB could be due to increased serum copper levels,which in turn stimulates factors like VEGF-A, thereby causing an increase in endometrial growth.

Increased Vascular Endothelial Growth Factor in the Ventricular Cerebrospinal Fluid as a Predictive Marker for Subsequent Ventriculoperitoneal Shunt Infection : A Comparison Study among Hydrocephalic Patients

Objective

The aim of this study is to determine the association between the cerebrospinal fluid (CSF) biomarkers and inflammation, and the predictive value of these CSF biomarkers for subsequent shunt associated infection.

Methods

We obtained CSF samples from the patients with hydrocephalus during ventriculoperitoneal (VP) shunt operations. Twenty-two patients were enrolled for this study and divided into 3 groups: subarachnoid hemorrhage (SAH)-induced hydrocephalus, idiopathic normal pressure hydrocephalus (INPH) and hydrocephalus with a subsequent shunt infection. We analyzed the transforming growth factor-β1, tumor necrosis factor-α, vascular endothelial growth factor (VEGF) and total tau in the CSF by performing enzyme-linked immunosorbent assay. The subsequent development of shunt infection was confirmed by the clinical presentations, the CSF parameters and CSF culture from the shunt devices.

Results

The mean VEGF concentration (±standard deviation) in the CSF of the SAH-induced hydrocephalus, INPH and shunt infection groups was 236±138, 237±80 and 627±391 pg/mL, respectively. There was a significant difference among the three groups (p=0.01). Between the SAH-induced hydrocephalus and infection groups and between the INPH and infection groups, there was a significant difference of the VEGF levels (p<0.01). However, the other marker levels did not differ among them.

Conclusion

The present study showed that only the CSF VEGF levels are associated with the subsequent development of shunt infection. Our results suggest that increased CSF VEGF could provide a good condition for bacteria that are introduced at the time of surgery to grow in the brain, rather than reflecting a sequel of bacterial infection before VP shunt.

Agmatine induces gastric protection against ischemic injury by reducing vascular permeability in rats

AIM: To investigate the effect of administration of agmatine (AGM) on gastric protection against ischemia reperfusion (I/R) injury.

METHODS: Three groups of rats (6/group); sham, gastric I/R injury, and gastric I/R + AGM (100 mg/kg, i.p. given 15 min prior to gastric ischemia) were recruited. Gastric injury was conducted by ligating celiac artery for 30 min and reperfusion for another 30 min. Gastric tissues were histologically studied and immunostained with angiopoietin 1 (Ang-1) and Ang-2. Vascular endothelial growth factor (VEGF) and monocyte chemoattractant protein-1 (MCP-1) were measured in gastric tissue homogenate. To assess whether AKt/phosphatidyl inositol-3-kinase (PI3K) mediated the effect of AGM, an additional group was pretreated with Wortmannin (WM) (inhibitor of Akt/PI3K, 15 μg/kg, i.p.), prior to ischemic injury and AGM treatment, and examined histologically and immunostained. Another set of experiments was run to study vascular permeability of the stomach using Evan’s blue dye.

RESULTS: AGM markedly reduced Evan’s blue dye extravasation (3.58 ± 0.975 μg/stomach vs 1.175 ± 0.374 μg/stomach, P < 0.05), VEGF (36.87 ± 2.71 pg/100 mg protein vs 48.4 ± 6.53 pg/100 mg protein, P < 0.05) and MCP-1 tissue level (29.5 ± 7 pg/100 mg protein vs 41.17 ± 10.4 pg/100 mg protein, P < 0.01). It preserved gastric histology and reduced congestion. Ang-1 and Ang-2 immunostaining were reduced in stomach sections of AGM-treated animals. The administration of WM abolished the protective effects of AGM and extensive hemorrhage and ulcerations were seen.

CONCLUSION: AGM protects the stomach against I/R injury by reducing vascular permeability and inflammation. This protection is possibly mediated by Akt/PI3K.

Paraneoplastic symptoms: cachexia, polycythemia, and hypercalcemia are, respectively, related to vascular endothelial growth factor (VEGF) expression in renal clear cell carcinoma

OBJECTIVES

To evaluate whether there is a relation between expression of vascular endothelial growth factor (VEGF) and any of the paraneoplastic syndromes (PNS) in clear cell renal cell carcinoma (ccRCC) patients.

MATERIALS AND METHODS

A total of 667 patients with ccRCC and at least one PNS were included. Thorough history taking, physical examinations, and laboratory tests were used to diagnose PNS. Immunohistochemistry was performed for VEGF evaluation.

RESULTS

There were 10 different PNS identified in the population. Sixty patients had a single paraneoplastic presentation. In all patients, presence of cachexia (n = 267, P < 0.0001), polycythemia (n = 40, P = 0.0014), and hypercalcemia (n = 48, P = 0.0006) was correlated to VEGF expression. Correlation was neither acquired in Stauffer's syndrome, pyrexia, elevated erythrocyte sedimentation rate (ESR), anemia, thrombocytosis, hypertension, neuromyopathy nor obtained within patients with single PNS.

CONCLUSIONS

Relations between PNS and VEGF expression in renal cell carcinoma (RCC) has not been studied yet. The results we gained hereby can help us further understand the mechanistic of PNS in RCC.

A potent soluble epoxide hydrolase inhibitor, t-AUCB, acts through PPARγ to modulate the function of endothelial progenitor cells from patients with acute myocardial infarction

BACKGROUND

Epoxyeicosatrienoic acids (EETs) are natural angiogenic mediators regulated by soluble epoxide hydrolase (sEH). Inhibitors of sEH can stabilize EETs levels and were reported to reduce atherosclerosis and inhibit myocardial infarction in animal models. In this work, we investigated whether increasing EETs with the sEH inhibitor t-AUCB would increase angiogenesis related function in endothelial progenitor cells (EPCs) from patients with acute myocardial infarction (AMI).

METHODS AND RESULTS

EPCs were isolated from 50 AMI patients and 50 healthy subjects (control). EPCs were treated with different concentrations of t-AUCB for 24h with or without peroxisome proliferator activated receptor γ (PPARγ) inhibitor GW9662. Migration of EPCs was assayed in trans-well chambers. Angiogenesis assays were performed using a Matrigel-Matrix in vitro model. The expression of vascular endothelial growth factor (VEGF), hypoxia-inducible factor 1α (HIF-1α) mRNA and protein in EPCs was measured by real-time PCR or Western blot, respectively. Also, the concentration of EETs in the culture supernatant was detected by ELISA. The activity of EPCs in the AMI patient group was reduced compared to healthy controls. Whereas increasing EET levels with t-AUCB promoted a dose dependent angiogenesis and migration in EPCs from AMI patients. Additionally, the t-AUCB dose dependently increased the expression of the angiogenic factors VEGF and HIF-α. Lastly, we provide evidence that these effects were PPARγ dependent.

CONCLUSION

The results demonstrate that the sEH inhibitor positively modulated the functions of EPCs in patients with AMI through the EETs-PPARγ pathway. The present study suggests the potential utility of sEHi in the therapy of ischemic heart disease.

Diagnostic value of AFP, h-TERT and VEGF mRNAs in peripheral blood of patients with hepatocellular carcinoma

AIM: To evaluate the diagnostic significance of alpha-fetoprotein (AFP), human telomerase reverse transcriptase (h-TERT) and vascular endothelial growth factor (VEGF) mRNAs in peripheral blood of patients with hepatocellular carcinoma (HCC).

METHODS: Fluorescence quantitative PCR (FQ-PCR) was used to detect the levels of AFP, h-TERT and VEGF mRNAs in peripheral blood samples from 40 patient with HCC, 20 patients with liver disease and 10 normal controls.

RESULTS: The positive rates of all three parameters were significantly higher in HCC patients than in controls (all P < 0.01). The positive expression of AFP and VEGF was not correlated with serum AFP levels in HCC patients (P > 0.05), whereas h-TERT mRNA had a correlation with serum AFP levels (P = 0.01). The positive rates of all three parameters were highly correlated with TNM stage in HCC patients (all P < 0.01). The specificity of AFP mRNA in the diagnosis of HCC was higher, and combined detection of AFP and h-TERT mRNAs had a higher accuracy.

CONCLUSION: AFP, h-TERT and VEGF mRNAs in peripheral blood can be used as auxiliary parameters for the diagnosis of HCC, and combined detection of AFP and h-TERT mRNAs in peripheral blood can increase the sensitivity and specificity for diagnosing HCC.

Identification of colorectal cancer metastasis markers by an angiogenesis-related cytokine-antibody array

AIM: To investigate the angiogenesis-related protein expression profile characterizing metastatic colorectal cancer (mCRC) with the aim of identifying prognostic markers.

METHODS: The expression of 44 angiogenesis-secreted factors was measured by a novel cytokine antibody array methodology. The study evaluated vascular endothelial growth factor (VEGF) and its soluble vascular endothelial growth factor receptor (sVEGFR)-1 protein levels by enzyme immunoassay (EIA) in a panel of 16 CRC cell lines. mRNA VEGF and VEGF-A isoforms were quantified by quantitative reverse-transcription polymerase chain reaction (Q-RT-PCR) and vascular endothelial growth factor receptor (VEGFR)-2 expression was analyzed by flow cytometry.

RESULTS: Metastasis-derived CRC cell lines expressed a distinctive molecular profile as compared with those isolated from a primary tumor site. Metastatic CRC cell lines were characterized by higher expression of angiopoietin-2 (Ang-2), macrophage chemoattractant proteins-3/4 (MCP-3/4), matrix metalloproteinase-1 (MMP-1), and the chemokines interferon γ inducible T cell α chemoattractant protein (I-TAC), monocyte chemoattractant protein I-309, and interleukins interleukin (IL)-2 and IL-1α, as compared to primary tumor cell lines. In contrast, primary CRC cell lines expressed higher levels of interferon γ (IFN-γ), insulin-like growth factor-1 (IGF-1), IL-6, leptin, epidermal growth factor (EGF), placental growth factor (PlGF), thrombopoietin, transforming growth factor β1 (TGF-β1) and VEGF-D, as compared with the metastatic cell lines. VEGF expression does not significantly differ according to the CRC cellular origin in normoxia. Severe hypoxia induced VEGF expression up-regulation but contrary to expectations, metastatic CRC cell lines did not respond as much as primary cell lines to the hypoxic stimulus. In CRC primary-derived cell lines, we observed a two-fold increase in VEGF expression between normoxia and hypoxia as compared to metastatic cell lines. CRC cell lines express a similar pattern of VEGF isoforms (VEGF₁₂₁, VEGF₁₆₅ and VEGF₁₈₉) despite variability in VEGF expression, where the major transcript was VEGF₁₂₁. No relevant expression of VEGFR-2 was found in CRC cell lines, as compared to that of human umbilical vein endothelial cells and sVEGFR-1 expression did not depend on the CRC cellular origin.

CONCLUSION: A distinct angiogenesis-related expression pattern characterizes metastatic CRC cell lines. Factors other than VEGF appear as prognostic markers and intervention targets in the metastatic CRC setting.

Targeted systemic therapies for hepatocellular carcinoma: Clinical perspectives, challenges and implications

Hepatocellular carcinoma (HCC) is a lethal disease in most patients, due to its aggressive course and a lack of effective systemic therapies for advanced disease. Surgical resection and liver transplantation remain the only curative options for a small subset of patients. Few patients with HCC are diagnosed early enough to be eligible for curative treatment. Angiogenesis inhibition is a natural therapeutic target for all solid tumors, but particularly for the highly vascularized HCC tumors. With the approval of the targeted agent sorafenib, there are now additional options for patients with HCC. Although sorafenib does produce some improvement in survival in HCC patients, the responses are not durable. In addition, there are significant dermatologic, gastrointestinal, and metabolic toxicities, and, as importantly, there is still limited knowledge of its usefulness in special subpopulations with HCC. Other angiogenesis inhibitors are in development to treat HCC both in the first-line setting and for use following sorafenib failure; the furthest in development is brivanib, a dual fibroblast growth factor pathway and vascular endothelial growth factor receptor inhibitor. Additional agents with antiangiogenic properties also in phase II and III development for the treatment of patients with HCC include bevacizumab, ramucirumab, ABT-869, everolimus and ARQ 197.

Serum vascular endothelial growth factor level in patients with hepatocellular carcinoma undergoing liver transplantation: experience of a single Western center

BACKGROUND

The strongest predictor of tumor relapse after liver transplantation for hepatocellular carcinoma (HCC) is vascular invasion, appreciated only on explant analysis. High serum level of vascular endothelial growth factor (VEGF) is associated with worse outcomes after resection or locoregional therapies but its role in liver transplantation remains undefined.

OBJECTIVE

We report the first western prospective study exploring serum VEGF in HCC liver transplant patients, correlating pre-operative serum VEGF with poor prognostic histologic features during explant analysis.

METHODS

Between May 2008, and June 2010, 75 HCC patients underwent liver transplantation at our institution. Serum VEGF was measured every 3 months until liver transplantation and correlated with histopathologic findings on explant.

RESULTS

There was no significant correlation between pre-transplant serum VEGF levels and tumor burden (median 31.0 pg/mL vs. 42.5 pg/mL, p=0.33, for tumors within and beyond the Milan criteria, respectively). Pre-transplant VEGF levels were higher in poorly differentiated tumors compared to well to moderately differentiated tumors, but not statistically significant (median 49.0 pg/mL vs. 31.0 pg/mL, p=0.26). Pre-transplant VEGF did not correlate with vascular invasion (median 37.0 pg/mL vs. 31.0 pg/mL, p=0.35, in the presence and absence of vascular invasion, respectively).

CONCLUSION

Pre-operative serum VEGF fails to predict unfavorable histologic HCC features in patients undergoing liver transplantation. Role of serum VEGF in liver transplant HCC patients remains unclear.

Bevacizumab-mediated interference with VEGF signaling is sufficient to induce a preeclampsia-like syndrome in nonpregnant women

Preeclampsia (gestational proteinuric hypertension) complicates 5% to 8% of all pregnancies, and is a major cause of maternal and perinatal morbidity and mortality. It is a multisystem disorder specific to human pregnancy and the puerperium. Although the etiology is unknown, increasing evidence from both animal and human studies suggests that an imbalance in circulating pro-(vascular endothelial growth factor [VEGF], placental growth factor) and anti-angiogenic factors (soluble fms-like tyrosine kinase 1, soluble endoglin) may be important. Bevacizumab (Avastin®; Genentech, South San Francisco, CA), a humanized recombinant monoclonal IgG antibody that binds VEGF, has been shown to inhibit endothelial cell proliferation, suppress angiogenesis, and shrink a variety of solid tumors. We present two cases of bevacizumab toxicity that mimic preeclampsia with a reversible syndrome characterized by acute-onset severe hypertension, proteinuria, central nervous system irritability (headache, photophobia, blurred vision, seizures), abnormal laboratory tests (elevated liver function tests, thrombocytopenia), and evidence of reversible posterior leukoencephalopathy on neuroimaging. In both cases, the clinical and laboratory manifestations returned to normal with discontinuation of bevacizumab therapy and supportive care. Bevacizumab toxicity can mimic preeclampsia in nonpregnant women. These data suggest that interference with VEGF signaling is sufficient to induce a preeclampsia-like syndrome in nonpregnant patients. VEGF signaling therefore appears to play a central role-perhaps the central role-in the pathogenesis of preeclampsia, and provides a potential biomarker for the prediction, prevention, and treatment of this dangerous disorder.

Utility of co-transplanting mesenchymal stem cells in islet transplantation

Islet transplantation is characterized by the transplantation of isolated islets from donor pancreata into a diabetic recipient. Although it is a viable choice in the treatment of insulin dependent diabetes mellitus, most patients (approximately 90%) require insulin five years after transplantation. Recently, the co-transplantation of mesenchymal stem cells (MSCs) and islets in animal studies has revealed the effectiveness of MSCs co-transplantation for improving islet function. The mechanisms underlying the beneficial impact of MSCs include immunomodulation and the promotion of angiogenesis. In this review, we discuss MSCs and how they support improved graft survival and function.

Recent advances in mechanisms and treatments of airway remodeling in asthma: a message from the bench side to the clinic

Airway remodeling in asthma is a result of persistent inflammation and epithelial damage in response to repetitive injury. Recent studies have identified several important mediators associated with airway remodeling in asthma, including transforming growth factor-β, interleukin (IL)-5, basic fibroblast growth factor, vascular endothelial growth factor, LIGHT, tumor necrosis factor (TNF)-α, thymic stromal lymphopoietin, IL-33, and IL-25. In addition, the epithelium mesenchymal transformation (EMT) induced by environmental factors may play an important role in initiating this process. Diagnostic methods using sputum and blood biomarkers as well as radiological interventions have been developed to distinguish between asthma sub-phenotypes. Human clinical trials have been conducted to evaluate biological therapies that target individual inflammatory cells or mediators including anti IgE, anti IL-5, and anti TNF-α. Furthermore, new drugs such as c-kit/platelet-derived growth factor receptor kinase inhibitors, endothelin-1 receptor antagonists, calcium channel inhibitors, and HMG-CoA reductase inhibitors have been developed to treat asthma-related symptoms. In addition to targeting specific inflammatory cells or mediators, preventing the initiation of EMT may be important for targeted treatment. Interestingly, bronchial thermoplasty reduces smooth muscle mass in patients with severe asthma and improves asthma-specific quality of life, particularly by reducing severe exacerbation and healthcare use. A wide range of different therapeutic approaches has been developed to address the immunological processes of asthma and to treat this complex chronic illness. An important future direction may be to investigate the role of mediators involved in the development of airway remodeling to enhance asthma therapy.

Correlation between Epstein-Barr virus infection and tumor angiogenesis in patients with gastric carcinoma

AIM: To evaluate the characteristics of Epstein-Barr virus (EBV)-associated gastric cancer and to explore the correlation between EBV infection and tumor angiogenesis in patients with gastric carcinoma.

METHODS: EBV infection was examined by localizing EBV-encoded small RNAs (EBERs) using in situ hybridization. Tumor angiogenesis was evaluated by examining the expression of VEGF protein using immunohistochemistry and tissue microarray technique. The association of EBV infection with clinicopathological parameters, including age, gender, tumor type, lymph node metastasis, and tumor stage, was analyzed. The correlation of VEGF expression with lymph node metastasis and Lauren's classification was also analyzed.

RESULTS: Among 486 patients, 18 showed nuclear expression of EBV. EBV staining was seen only in tumor cells. 14 of 18 patients with EBV-associated gastric cancer had regional lymph node metastasis. Of note, metastatic tumor cells in all of the involved lymph nodes contained EBV. EBER-positive gastric carcinomas tended to have lymphoid stroma (17/18) and were mostly poorly differentiated type (P<0.05). There was no significant difference in TNM stage between EBV-positive and -negative carcinomas (P>0.05). The positive rate of VEGF protein expression was 28.2% (137/486). Angiogenesis was significantly associated with lymph node metastasis and TNM stage (both P<0.05). EBV infection was closely correlated with angiogenesis (r = 0.119, P = 0.009).

CONCLUSION: EBV is present exclusively in gastric cancer cells and tumor cells in all of the lymph nodes involved. EBV-positive gastric cancer has distinct clinicopathological features. Angiogenesis may be a good predictor of metastasis and prognosis of gastric carcinoma in patients with EBV-associated gastric cancer.

Progress in understanding the relationship between vascular endothelial growth factor and digestive tumors

Digestive tumors account for a large portion of human malignancies, and their incidence and mortality are on the rise. Neovascularization plays a critical role in the metastasis of tumors. Vascular endothelial growth factor (VEGF) is one of the best characterized angiogenic regulators. There is close relationship between VEGF and tumor growth, invasion and metastasis. VEGF has become a research hot for diagnosis, targeted therapy and prognosis of tumors. The purpose of this review is to review the recent progress in understanding the relationship between VEGF and digestive tumors.

The effectiveness of cabergoline for the prevention of ovarian hyperstimulation syndrome

Type 2 receptors for vascular endothelial growth factor are believed to be involved in the pathophysiology of ovarian hyperstimulation syndrome (OHSS). The objective of this study was to examine the preventive effects of cabergoline on OHSS and its complications. The study is a non randomized clinical trial conducted in 2006-2008 on 75 patients, which were at risk of OHSS and underwent assisted reproductive techniques. The diagnosis and severity of OHSS were determined using standard criteria. The study included an intervention and a control group. The intervention group comprised of 50 women at risk of OHSS, who were treated with cabergoline (1 mg every other day for 8 days) commencing from the day of ovum pick up. The control group comprised of 25 historical cases, which were similar to the case group. The latter group did not receive cabergoline, and their OHSS, if occurred, were managed conservatively after hospital admission. The rates of OHSS, baseline characteristics, ovarian stimulation parameters, and pregnancy occurrence were compared. There was no significant difference between baseline characteristics or ovarian stimulation parameters form the two groups. The incidence of OHSS in the cabergoline-treated group, was significantly (P=0.01) lower than that in the control group (12% vs 36%). Embryo freezing was significantly (P=0.001) lower in the control group, but cycle cancellation was significantly (0.03) lower in the cabergoline group. The findings of the study indicate that cabergoline reduces the incidence of OHSS, and is not associated with adverse effects on pregnancy.

Lymphangiogenesis in cancers: A therapy target

Tumor metastasis is a major cause of death among cancer patients. The lymphatic vasculature is an important route for the metastatic spread of cancer. Recent research has indicated that vascular endothelial growth factor C (VEGF-C), VEGF-D and VEGF receptor-3 (VEGFR-3) are closely related to tumor-induced lymphangiogenesis, tumor metastasis and prognosis. Numerous studies demonstrate that the VEGF-C/VEGF-D/VEGFR-3 signaling axis plays a leading role in the regulation of tumor lymphangiogenesis and is related to tumor metastasis and prognosis. It has been confirmed that inhibition of the VEGF-C/VEGF-D/VEGFR-3 signaling axis can exert anti-lymphangiogenic effect and thereby prevent tumor metastasis in animal models. In this paper we review the molecular biology of lymphangiogenesis, its relationship with cancer metastasis, and the clinical implications of inhibition of lymphangiogenesis.

Intravitreal bevacizumab (avastin) as an adjuvant for the treatment of posterior scleritis

We report a case of posterior scleritis effectively managed with intravitreal bevacizumab. A 71-year-old woman was diagnosed with posterior scleritis. Although she was initially treated with systemic steroids, her clinical presentation deteriorated. She was then treated with a single intravitreal injection of bevacizumab and aqueous humor collection. The aqueous level of vascular endothelial growth factor prior to the intravitreal injection was 880.51 pg/mL, greater than that in the healthy control group (p < 0.001). One month later, the scleritis was completely resolved, and the patient remained stable during six months of follow-up. Intravitreal bevacizumab appears to be an effective adjuvant therapy for patients with posterior scleritis.

Expression of Brg1, VEGF and COX-2 in Peutz-Jeghers syndrome

AIM: To detect the expression of brahma-related gene 1 (Brg1), vascular endothelial growth factor (VEGF) and cyclooxygenase 2 (COX-2) proteins in Peutz-Jeghers syndrome (PJS) and to analyze their clinical significance.

METHODS: Immunohistochemistry was used to detect the expression of Brg1, VEGF and COX-2 proteins in 72 PJS samples, 12 normal small intestinal mucosal tissue samples and 30 cancer tissue samples.

RESULTS: The positive rates of Brg1, VEGF and COX-2 expression were significantly higher in PJS than in normal mucosal tissue (54.17% vs 16.67%, 58.33% vs 8.33%, 62.50% vs 25.00%, all P < 0.01) and in cancer tissue than in PJS (76.67% vs 54.17%, 80.00% vs 58.33%, 83.33% vs 62.50% all P < 0.01). In PJS, positive correlations were found between Brg1 and VEGF expression and between Brg1 and COX-2 expression.

CONCLUSION: Brg1, VEGF and COX-2 may play a role in the occurrence of PJS.

Vascular endothelial growth factor levels in childhood acute lymphoblastic and myeloblastic leukemia

Angiogenesis has been associated with the growth, dissemination and metastasis and has been shown to be a prognostic. Although there are some data suggesting that angiogenesis may have a role in the pathophysiology of leukemia, its role in patient prognosis is yet to be defined. We analyzed the expression level of vascular endothelial growth factor (VEGF), an angiogenesis promoter and its possible- prognostic value in bone marrow samples at the time of diagnosis and remission of acute childhood leukemia patients. Besides 46 patients diagnosed as ALL or AML, 16 children were also included as a control group in the study. Our data have demonstrated that VEGF levels of AML patients were found higher than the control group statistically (P = 0.022). However we could not find any significant difference between VEGF levels of diagnosis and remission in both AML and ALL groups by blastic VEGF expression (P > 0.05). In this study the higher levels of VEGF in AML patients is one of the main findings although we were not able to assess any role of VEGF in predicting prognosis in pediatric leukemia patients by evaluating blastic cell VEGF expression. These results have demonstrated that the relationship between angiogenesis or angiogenesis promoters and hematological malignancies is not clear and simple as different methods or different cells beside different angiogenesis promotors are involved to these studies. So that not only tumor cells and their cytokines but also surrounding cells and their cytokines must be taken into consideration with the standardized study methods in the further studies to obtain a promising treatment approach.

Integrin-linked kinase in gastric cancer cell attachment, invasion and tumor growth

AIM: To investigate the effects of integrin-linked kinase (ILK) on gastric cancer cells both in vitro and in vivo.

METHODS: ILK small interfering RNA (siRNA) was transfected into human gastric cancer BGC-823 cells and ILK expression was monitored by real-time quantitative polymerase chain reaction, Western blotting analysis and immunocytochemistry. Cell attachment, proliferation, invasion, microfilament dynamics and the secretion of vascular endothelial growth factor (VEGF) were also measured. Gastric cancer cells treated with ILK siRNA were subcutaneously transplanted into nude mice and tumor growth was assessed.

RESULTS: Both ILK mRNA and protein levels were significantly down-regulated by ILK siRNA in human gastric cancer cells. This significantly inhibited cell attachment, proliferation and invasion. The knockdown of ILK also disturbed F-actin assembly and reduced VEGF secretion in conditioned medium by 40% (P < 0.05). Four weeks after injection of ILK siRNA-transfected gastric cancer cells into nude mice, tumor volume and weight were significantly reduced compared with that of tumors induced by cells treated with non-silencing siRNA or by untreated cells (P < 0.05).

CONCLUSION: Targeting ILK with siRNA suppresses the growth of gastric cancer cells both in vitro and in vivo. ILK plays an important role in gastric cancer progression.

Portal vein infusion of recombinant vascular endothelial growth factor 165 mitigates liver fibrosis in cirrhotic rats

AIM: To evaluate the effect of portal vein infusion of recombinant vascular endothelial growth factor (VEGF) 165 on liver fibrosis in rats with cirrhosis.

METHODS: Fifty male SD rats were randomly divided into normal group (n = 10) and model group (n = 40). The model group was used to induce cirrhosis using the thioacetamide approach. After 10 wk, 25 cirrhotic rats were randomly divided into experimental group (n = 15) and model control group (n = 10). The experimental group was intubated for implantation of an Alzet osmotic pump, which was used to infuse recombinant VEGF165 via the portal vein for 2 wk. The normal group and model control group underwent sham operation. All rats were killed after 2 wk, and HE staining was used to observe the pathological changes in liver tissue. Serum hyaluronic acid and laminin were measured using radioimmunoassay method. Immunohistochemistry was used to detect the expression of type I and type IV collagen in the liver.

RESULTS: Degeneration and necrosis of liver cells, diffuse proliferation of fibrous connective tissue and formation of pseudo lobules occurred in the model control group. In the experimental group, degeneration and necrosis of liver cells were milder and the rate of liver fibrosis was improved significantly compared to the model control group (P < 0.01). Compared to the normal group, serum hyaluronic acid and laminin concentrations increased significantly in the model control group (P < 0.01). However, serum concentrations of hyaluronic acid and laminin was significantly lower in the experimental group than in the model control group (412.63 μg/L ± 85.18 μg/L vs 741.60 μg/L ± 72.83 μg/L; 58.87 μg/L ± 5.46 μg/L vs 92.80 μg/L ± 8.41 μg/L; both P < 0.01). The expression levels of type I and type IV collagen in the liver was significantly lower in the experimental group than in the model control group (6.84 ± 0.96, 8.25 ± 0.82 vs 18.38 ± 1.86, 20.86 ± 2.48, all P < 0.01).

CONCLUSION: Portal vein infusion of VEGF165 can relieve liver fibrosis in rats with cirrhosis.

Clinical significance of expression of caveolin-1 and vascular endothelial growth factor in colorectal carcinoma

AIM: To detect the expressions of caveolin-1 (Cav-1) and vascular endothelial growth factor (VEGF) in colorectal cancer and to analyze their correlation with the clinicopathological features of colorectal cancer.

METHODS: Immunohistochemistry was used to detect the expression of Cav-1 and VEGF in 83 colorectal carcinoma specimens and matched normal colorectal mucosal specimens.

RESULTS: The positive rate of Cav-1 expression was significantly lower in colorectal carcinoma than in normal colorectal mucosa (38.6% vs 81.9%, P < 0.01). VEGF was over-expressed in colorectal cancer compared to matched normal colorectal tissue (74.7% vs 13.3%, P < 0.01). The expression of Cav-1 and VEGF was significantly correlated with tumor differentiation, invasion depth and lymph node metastasis (all P < 0.05), but not with patient's age, sex or tumor size. There is a negative correlation between Cav-1 and VEGF expression in colorectal cancer (r = -0.393, P < 0.01).

CONCLUSION: The absent expression of Cav-1 and over-expression of VEGF may play an important role in the development and progression of colorectal carcinoma.

Role of endoglin and VEGF family expression in colorectal cancer prognosis and anti-angiogenic therapies

Colorectal cancer (CRC) is one of the cancer models and most of the carcinogenic steps are presently well understood. Therefore, successful preventive measures are currently used in medical practice. However, CRC is still an important public health problem as it is the third most common cancer and the fourth most frequent cause of cancer death worldwide. Nowadays, pathologic stage is a unique and well-recognized prognostic indicator, however, more accurate indicators of the biologic behavior of CRC are expected to improve the specificity of medical treatment. Angiogenesis plays an important role in the growth and progression of cancer but its role as a prognostic factor is still controversial. Probably the most important clinical implication of tumor angiogenesis is the development of anti-angiogenic therapy. The goal of this review is to critically evaluate the role of angiogenic markers, assessed by either endoglin-related microvessel density or expression of vascular endothelial growth factor family members in the CRC setting and discuss the role of these angiogenic markers in anti-angiogenic therapies.

Comparison of EGF with VEGF non-viral gene therapy for cutaneous wound healing of streptozotocin diabetic mice

BACKGROUND

To accelerate the healing of diabetic wounds, various kinds of growth factors have been employed. It is the short half-life of administered growth factors in hostile wound beds that have limited wide-spread clinical usage. To overcome this limitation, growth factor gene therapy could be an attractive alternative rather than direct application of factors onto the wound beds. We administered two growth factor DNAs, epidermal growth factor (EGF) and vascular endothelial growth factor (VEGF) into a cutaneous wound on diabetic mice. We compared the different characteristics of the healing wounds.

METHODS

Streptozotocin was injected intraperitoneally to induce diabetes into C57BL/6J mice. The ultrasound micro-bubble destruction method with SonoVue as a bubbling agent was used for non-viral gene delivery of EGF(828) and VEGF(165) DNAs. Each gene was modified for increasing efficacy as FRM-EGF(828) or minicircle VEGF(165). The degree of neoangiogenesis was assessed using qualitative laser Doppler flowmetry. We compared wound size and histological findings of the skin wounds in each group.

RESULTS

In both groups, accelerated wound closure was observed in the mice receiving gene therapy compared with non treated diabetic control mice. Blood flow detected by laser doppler flowmetry was better in the VEGF group than in the EGF group. Wound healing rates and histological findings were more accelerated in the EGF gene therapy group than the VEGF group, but were not statistically significant.

CONCLUSION

Both non-viral EGF and VEGF gene therapy administrations could improve the speed and quality of skin wound healing. However, the detailed histological characteristics of the healing wounds were different.

Tan IIA inhibits COX-2-regulated VEGF expression in human colon cancer HCT-116 cells

AIM: To investigate the effect of tanshinone IIA (Tan IIA), an active component of salvia miltiorrhiza, on cell proliferation and cyclooxygenase-2 (COX-2)-regulated vascular endothelial growth factor (VEGF) expression in human colon cancer HCT-116 cells.

METHODS: MTT assay was used to evaluate the effect of Tan IIA on the proliferation of HCT-116 cells. HCT-116 cells were co-transfected transiently with the recombinant plasmid pGL3-Basic-COX-2-promoter and control vector pRL-TK and randomly divided into blank group, control group, and Tan IIA group. Dual luciferase reporter assay was used to observe the activity of COX-2 promoter 48 h after treatment with Tan IIA. HCT-116 cells were transfected with the pIRESI-COX-2 plasmid and divided into three groups as above. The expression of COX-2 mRNA in transfected cells was detected by real-time PCR, and the level of VEGF in culture medium was assayed by ELISA.

RESULTS: Tan IIA had obvious inhibition on the proliferation of HCT-116 cells. The half maximal inhibitory concentrations (IC₅₀) at 24, 48, and 72 h were 40.3 μmol/L ± 5.22 μmol/L, 12.9 μmol/L ± 3.24 μmol/L, and 8.5 μmol/L ± 1.47 μmol/L, respectively, and the maximal no-effect dose at 24 h was 10 μmol/L. At 48 h after transfection with plasmids carrying the COX-2-promoter and COX-2 cDNA, the activity of COX-2 promoter and expression of COX-2 mRNA were obviously up-regulated (both P < 0.01), and the concentration of VEGF was three times higher than that in control cells (P < 0.05). Treatment with 10 μmol/L Tan IIA significantly down-regulated the expression of COX-2 and VEGF in transfected cells (P < 0.05).

CONCLUSION: Tan IIA down-regulates VEGF expression and inhibits cell proliferation possibly by regulating COX-2 promoter activity and mRNA expression in HCT-116 cells.

Clinical significance of matrix metalloproteinases-3 and vascular endothelial growth factor expression in pancreatic carcinoma

AIM: To investigate the expression of vascular endothelial growth factor (VEGF) and matrix metalloproteinases-3 (MMP-3) in pancreatic carcinoma (PC) and to analyze their relationship with tumor angiogenesis, invasion and metastasis.

METHODS: The protein expression of VEGF and MMP-3 and microvessel density (MVD) were detected by immunohistochemistry in 56 PC specimens and 56 normal pancreatic tissue specimens.

RESULTS: The positive rates of both MMP-3 and VEGF were significantly higher in PC than in normal pancreatic tissue (75.00% vs 3.57%, 67.85% vs 1.78%, both P < 0.01). There was a positive correlation between the expression of VEGF and that of MMP-3. Higher expression of MMP-3 was detected in late-stage PC and PC with lymph node metastasis. The expression of VEGF was correlated with clinical stage (P < 0.05). MVD was correlated with expression of MMP-3 and VEGF in PC (both P < 0.05).

CONCLUSION: MMP-3 and VEGF may promote tumor angiogenesis and play an important role in the development and progression of PC. Detection of MMP-3 expression could be used to predict early metastasis of PC. Lower expression of VEGF may be related to lower arterial blood supply in PC.

(-)-Epigallocatechin-3-gallate inhibits VEGF expression induced by IL-6 via Stat3 in gastric cancer

AIM: To demonstrate that (-)-Epigallocatechin-3-gallate (EGCG) inhibits vascular endothelial growth factor (VEGF) expression and angiogenesis induced by interleukin-6 (IL-6) via suppressing signal transducer and activator of transcription 3 (Stat3) activity in gastric cancer.

METHODS: Human gastric cancer (AGS) cells were treated with IL-6 (50 ng/mL) and EGCG at different concentrations. VEGF, total Stat3 and activated Stat3 protein levels in the cell lyses were examined by Western blotting, VEGF protein level in the conditioned medium was measured by enzyme-linked immunosorbent assay, and the level of VEGF mRNA was evaluated by reverse transcription polymerase chain reaction (RT-PCR). Stat3 nuclear translocation was determined by Western blotting with nuclear extract, and Stat3-DNA binding activity was examined with Chromatin immunoprecipitation (ChIP) assay. IL-6 induced endothelial cell proliferation was measured with 3-[4, 5-dimethylthiazol-2-yl]-2, 5-diphenyl tetrazoliumbromide assay, in vitro angiogenesis was determined with endothelial cell tube formation assay in Matrigel, and IL-6-induced angiogenesis in vitro was measured with Matrigel plug assay.

RESULTS: There was a basal expression and secretion of VEGF in AGS cells. After stimulation with IL-6, VEGF expression was apparently up-regulated and a 2.4-fold increase was observed. VEGF secretion in the conditioned medium was also increased by 2.8 folds. When treated with EGCG, VEGF expression and secretion were dose-dependently decreased. IL-6 also increased VEGF mRNA expression by 3.1 folds. EGCG treatment suppressed VEGF mRNA expression in a dose-dependent manner. EGCG dose-dependently inhibited Stat3 activation induced by IL-6, but did not change the total Stat3 expression. When treated with EGCG or AG490, VEGF expressions were reduced to the level or an even lower level in the tumor cells not stimulated with IL-6. However, PD98059 and LY294002 did not change VEGF expression induced by IL-6. EGCG inhibited Stat3 nucleus translocation, and Stat3-DNA binding activity was also markedly decreased by EGCG. Furthermore, EGCG inhibited IL-6 induced vascular endothelial cell proliferation and tube formation in vitro and angiogenesis in vitro.

CONCLUSION: EGCG inhibits IL-6-induced VEGF expression and angiogenesis via suppressing Stat3 activity in gastric cancer, which has provided a novel mechanistic insight into the anti-angiogenic activity of EGCG.

ANXA-2 and VEGF promote invasiveness of human liver cancer HepG2 cells

AIM: To investigate the role of annexin-2 (ANXA-2) and vascular endothelial growth factor (VEGF) in promoting invasiveness of human liver cancer HepG2 cells .

METHODS: After HepG2 cells were treated with different doses of 5-fluorouracil, cell invasiveness was detected by Transwell assay, and the mRNA and protein expression of ANXA-2 and VEGF was detected by RT-PCR and Western blot, respectively.

RESULTS: The invasiveness of HepG2 cells decreased with the increase in the dose of 5-fluorouracil, with significant differences among cells treated with different doses of 5-fluorouracil (22 ± 5, 25 ± 4, 13 ± 2, 12 ± 2 vs 39 ± 7, all P < 0.05). The mRNA and protein expression of ANXA2 and VEGF in HepG2 cells decreased gradually with the increase in the dose of 5-fluorouracil (ANXA2 mRNA: 0.527 ± 0.008, 0.419 ± 0.046, 0.213 ± 0.007, 0.176 ± 0.007 vs 0.718 ± 0.008; ANXA2 protein: 0.669 ± 0.055, 0.484 ± 0.072, 0.180 ± 0.034, 0.099 ± 0.009 vs 1.236 ± 0.102; VEGF mRNA: 0.818 ± 0.016, 0.558 ± 0.101, 0.386 ± 0.009, 0.352 ± 0.017 vs 1.176 ± 0.035; VEGF protein: 0.960 ± 0.085, 0.962 ± 0.056, 0.376 ± 0.069, 0.219 ± 0.008 vs 1.124 ± 0.170, all P < 0.001). There were significant correlations between the mRNA and protein expression of ANXA2 and VEGF (r_p = 0.900, r_w = 0.856).

CONCLUSION: The expression of ANXA2 and VEGF in HepG2 cells decreased gradually with the increase in the dose of 5-fluorouracil. ANXA2 and VEGF may play an important role in the invasion and metastasis of hepatocellular carcinoma.

Effect of exogenous administration of vascular endothelial growth factor on hepatic microvessel density in rats with liver cirrhosis

AIM: To investigate the effect of portal vein administration of vascular endothelial growth factor on the density of hepatic microvessels in rats with liver cirrhosis.

METHODS: Twenty-five male Sprague-Dawley rats with portal hypertension were randomly divided into two groups: treatment group (n = 15) and model group (n = 10). The treatment group was given recombinant rat vascular endothelial growth factor 165 (30 ng/d) via the portal vein for 2 weeks. The model group underwent only sham operation. Ten normal rats were used as normal controls. After treatment, liver histopathology was examined by light microscopy and sinusoidal ultrastructure was observed by transmission electron microscopy. The density of hepatic microvessels was detected by immunostaining of von Willebrand factor (vWF).

RESULTS: Light microscopy examination showed that hepatic fibrosis improved in the treatment group compared with the model group. Electron microscopy analysis showed decreased number of fenestrations in sinusoidal endothelial cells, basement membrane formation, and irregular hepatic sinus endothelial cells. These pathological changes were more severe in the model group than in the treatment group. Microvessel density was higher in fibrotic stroma (2.04 ± 0.61 vs 1.26 ± 0.30, P < 0.01) but lower in liver parenchyma (0.74 ± 0.05 vs 1.32 ± 0.48, P < 0.01) in the treatment group than in the model group. However, microvessel density in both liver stroma and parenchyma was higher in the treatment and model groups than in the normal control group (1.26 ± 0.30, 2.04 ± 0.61 vs 0.70 ± 0.07; 1.32 ± 0.48, 0.74 ± 0.05 vs 0.28 ± 0.08, all P < 0.05).

CONCLUSION: Exogenous administration of vascular endothelial growth factor is capable of increasing the number of microvessels in fibrotic stroma but decreasing that in liver parenchyma.

Effects of spironolactone and losartan on diabetic nephropathy in a type 2 diabetic rat model

BACKGROUND

While there is an evidence that the anti-inflammatory properties of spironolactone can attenuate proteinuria in type 2 diabetes, its effects on vascular endothelial growth factor (VEGF) expression in diabetic nephropathy have not been clearly defined. In this study, we examined the effects of spironolactone, losartan, and a combination of these two drugs on albuminuria, renal VEGF expression, and inflammatory and oxidative stress markers in a type 2 diabetic rat model.

METHODS

Thirty-three Otsuka-Long-Evans-Tokushima-Fatty (OLETF) rats were divided into four groups and treated with different medication regimens from weeks 25 to 50; OLETF diabetic controls (n=5), spironolactone-treated (n=10), losartan-treated (n=9), and combination of spironolactone- and losartan-treated (n=9).

RESULTS

At week 50, the albumin-to-creatinine ratio was significantly decreased in the losartan and combination groups compared to the control OLETF group. No decrease was detected in the spironolactone group. There was a significant reduction in renal VEGF, transforming growth factor (TGF)-β, and type IV collagen mRNA levels in the spironolactone- and combination regimen-treated groups. Twenty-four hour urine monocyte chemotactic protein-1 levels were comparable in all four groups but did show a decreasing trend in the losartan and combination regimen groups. Twenty-four hour urine malondialdehyde levels were significantly decreased in the spironolactone- and combination regimen-treated groups.

CONCLUSION

These results suggest that losartan alone and a combined regimen of spironolactone and losartan could ameliorate albuninuria by reducing renal VEGF expression. Also, simultaneous treatment with spironolactone and losartan may have protective effects against diabetic nephropathy by decreasing TGF-β and type IV collagen expression and by reducing oxidative stress in a type 2 diabetic rat model.

Molecularly targeted therapy for gastric cancer: current status and future prospects

Gastric cancer remains the second leading cause of cancer death worldwide. Currently, chemotherapy is the mainstay of treatment for patients with metastatic gastric cancer. Although new chemotherapeutic regimens improved the survival of patients with advanced gastric cancer, the median survival in all randomized trials remains unsatisfactory. Novel treatment options are urgently needed to improve the outcome of patients with advanced gastric cancer. Understanding the molecular pathways that characterize cell growth, apoptosis, angiogenesis and invasion has enabled us to use new approaches to treat this disease in clinical situations. The aim of this review is to summarize the most recent publications on targeted therapies for advanced gastric cancer.

Akt activation promotes angiogenesis in gastric cancer

AIM: To determine the expression and activation of Akt in gastric cancer and to investigate the role of Akt activation in tumor angiogenesis in gastric cancer.

METHODS: Forty-eight fresh gastric adenocarcinoma tissue samples and matched normal gastric mucosal samples were collected surgically from patients with gastric cancer and immediately frozen in liquid nitrogen. The expression levels of Akt and phosphorylated Akt (pAkt) in the above tissue samples were measured by Western blot. Immunohistochemistry was conducted to evaluate the expression levels of pAkt and vascular endothelial growth factor (VEGF) and microvessel density (MVD) in gastric adenocarcinoma .

RESULTS: Western blot analysis demonstrated that Akt protein was expressed in 20 cancer tissue samples (20/20) and 19 normal tissue samples (19/20). The mean expression level of Akt protein in gastric adenocarcinoma was 2.7-fold higher than that in normal gastric mucosal tissue (0.186 ± 0.013 vs 0.069 ± 0.009, P < 0.001). The expression level of pAkt protein in gastric adenocarcinoma was 4.1-fold higher than that in tumor-adjacent gastric mucosal tissue (0.164 ± 0.025 vs 0.040 ± 0.006, P < 0.01). Immunohistochemically, pAkt was found to be expressed in 67.7% (32/48) of gastric cancer tissue samples and 58.3% (28/48) of normal tissue samples. The abundance of pAkt was significantly associated with tumor differentiation (χ² = 8.280, P < 0.05) and TNM stage (χ² = 8.526, P < 0.05). The mean MVD was 40.6 ± 15.1 in 48 gastric cancer tissue samples. The mean MVD in pAKT-positive cancer tissue samples was significantly higher than that in pAkt-negative ones (45.5 ± 20.3 vs 30.6 ± 12.1, P < 0.01). The mean MVD in VEGF-positive cancer tissue samples was significantly higher than that in VEGF-negative ones. In addition, pAkt abundance was significantly associated with VEGF expression (χ² = 12.89, P = 0.012).

CONCLUSION: Overexpression of Akt and pAkt occurs in gastric adenocarcinoma and may promote tumor angiogenesis by up-regulating VEGF expression.

Interleukin-24 is correlated with differentiation and lymph node numbers in rectal cancer

AIM: To assess the significance of interleukin (IL)-24 and vascular endothelial growth factor (VEGF) expression in lymph-node-positive rectal cancer.

METHODS: Between 1998 and 2005, 90 rectal adenocarcinoma patients with lymph node involvement were enrolled. All patients received radical surgery and postoperative pelvic chemoradiotherapy of 50.4-54.0 Gy. Chemotherapy of 5-fluorouracil and leucovorin or levamisole was given intravenously during the first and last week of radiotherapy, and then monthly for about 6 mo. Expression of IL-24 and VEGF was evaluated by immunohistochemical staining of surgical specimens, and their relations with patient characteristics and survival were analyzed. The median follow-up of surviving patients was 73 mo (range: 52-122 mo).

RESULTS: IL-24 expression was found in 81 out of 90 patients; 31 showed weak intensity and 50 showed strong intensity. VEGF expression was found in 64 out of 90 patients. Negative and weak intensities of IL-24 expression were classified as negative expression for analysis. IL-24 expression was significantly reduced in poorly differentiated tumors in comparison with well or moderately differentiated tumors (P = 0.004), N2b to earlier N stages (P = 0.016), and stage IIIc to stage IIIa or IIIb (P = 0.028). The number of involved lymph nodes was also significantly reduced in IL-24-positive patients in comparison with IL-24-negative ones.There was no correlation between VEGF expression and patient characteristics. Expression of IL-24 and VEGF was not correlated with survival, but N stage and stages were significantly correlated with survival.

CONCLUSION: IL-24 expression was significantly correlated with histological differentiation, and inversely correlated with the degree of lymph node involvement in stage III rectal cancer.

Liver cancer: Targeted future options

Hepatocellular carcinoma (HCC) has a poor prognosis and systemic chemotherapies have disappointing results. The increasing knowledge of the molecular biology of HCC has resulted in novel targets, with the vascular endothelial growth factor and epidermal growth factor receptor (EGFR)-related pathways being of special interest. New blood vessel formation (angiogenesis) is essential for the growth of solid tumors. Anti-angiogenic strategies have become an important therapeutic modality for solid tumors. Several agents targeting angiogenesis-related pathways have entered clinical trials or have been already approved for the treatment of solid tumors. These include monoclonal antibodies, receptor tyrosine kinase inhibitors and immunomodulatory drugs. HCC is a highly vascular tumor, and angiogenesis is believed to play an important role in its development and progression. This review summarizes recent advances in the basic understanding of the role of angiogenesis in HCC as well as clinical trials with novel therapeutic approaches targeting angiogenesis and EGFR-related pathways.

New perspectives on diabetic vascular complications: the loss of endogenous protective factors induced by hyperglycemia

Diabetic vascular complications are among the leading causes of morbidity and mortality in diabetic patients. In the past, many studies have focused on the mechanisms of hyperglycemia-induced chronic vascular complications via the formation of toxic metabolites such as oxidative stress, advanced glycosylated end products, persistent activation of protein kinase C, and increased sorbitol concentrations. However, vascular complications result from imbalances caused by increases in systemic toxic metabolites, such as those that occur under conditions of hyperglycemia and dyslipidemia, and by reductions in endogenous protective factors such as insulin, vascular endothelial growth factor, and platelet derived growth factor. This review outlines some of the evidence supporting the importance of enhancing endogenous regenerative factors.

Correlation between TFF 2 expression and tumor angiogenesis in gastric carcinoma, adjacent carcinoma and normal gastric mucosa

AIM: To investigate the correlation among the expression of trefoil factor 2 (TFF2) and vascular endothelial growth factor (VEGF) and microvessel density (MVD) in gastric carcinoma.

METHODS: The expression of TFF2 and VEGF and MVD were determined by immunohistochemistry in 50 gastric carcinoma specimens, 50 tumor-adjacent gastric mucosal specimens, and 30 normal gastric mucosa specimens.

RESULTS: The expression level of TFF2 was highest in normal gastric mucosa, followed by tumor-adjacent gastric mucosa and gastric carcinoma (165.80 ± 16.42, 184.44 ± 19.02, 206.79 ± 17.62, all P < 0.01). The expression of TFF2 in gastric cancer was significantly associated with the degree of tumor differentiation and lymph node metastasis (both P < 0.01). The expression level of VEGF and MVD were lowest in normal gastric mucosa, followed by tumor-adjacent gastric mucosa and gastric carcinoma (36.7%, 42.0%, 72.6%; 26.35 ± 4.54, 30.78 ± 5.64, 40.13 ± 6.92, all P < 0.01). The expression of VEGF and MVD in gastric cancer were associated with tumor differentiation, invasion and lymph node metastasis (all P < 0.01). There is a negative correlation between the expression of TFF2 and MVD (r = -0.781, P < 0.01).

CONCLUSION: TFF2 may be a negative regulatory factor of gastric carcinogenesis. The expression of TFF2 is down-regulated during the development of gastric cancer, while that of VEGF and MVD are up-regulated during this process.

Angiogenic markers endoglin and vascular endothelial growth factor in gastroenteropancreatic neuroendocrine tumors

AIM: To investigate the expression and potential prognostic role of vascular endothelial growth factor (VEGF) and endoglin in gastroenteropancreatic neuroendocrine tumors (GEP-NETs).

METHODS: Microvessel density (MVD) in GEP-NETs was evaluated using endoglin and CD31 immunohistochemistry. In addition, tissue levels of endoglin and VEGF were determined in homogenates by ELISA.

RESULTS: Endoglin was highly expressed on tumor endothelial cells. CD31 MVD in GEP-NETs was significantly higher compared to endoglin MVD (P < 0.01). Two- to four-fold higher tissue levels of endoglin and VEGF were seen in tumors compared to associated normal tissue. This increased endoglin tissue expression in tumors was significantly related to tumor size (P < 0.01), presence of metastases (P = 0.04), and a more advanced tumor stage (P = 0.02), whereas expression of VEGF was not.

CONCLUSION: We suggest that endoglin is a potential marker to indicate and predict metastases, which might be useful in the post-resection therapeutic approach of patients with GEP-NETs.

Engagement of toll-like receptor 3 induces vascular endothelial growth factor and interleukin-8 in human rheumatoid synovial fibroblasts

BACKGROUND/AIMS

Angiogenesis, which is a critical step in the initiation and progression of rheumatoid arthritis (RA), involves pro-angiogenic factors, including interleukin (IL)-8 and vascular endothelial growth factor (VEGF). We investigated the role of Toll-like receptor 3 (TLR3) in the regulation of pro-angiogenic factors in RA fibroblast-like synoviocytes (FLS).

METHODS

FLS were isolated from RA synovial tissues and stimulated with the TLR3 ligand, poly (I:C). The levels of VEGF and IL-8 in the culture supernatants were measured using enzyme-linked immunosorbent assays, and the mRNA levels were assessed by semiquantitative reverse transcription-polymerase chain reaction. The expression patterns of VEGF and IL-8 in the RA synovium and osteoarthritis (OA) synovium were compared using immunohistochemistry.

RESULTS

The expression levels of TLR3, VEGF, and IL-8 were significantly higher in the RA synovium than in the OA synovium. VEGF and IL-8 production were increased in the culture supernatants of RA FLS stimulated with poly (I:C), and the genes for these proteins were up-regulated at the transcriptional level after poly (I:C) treatment. Treatment with inhibitors of nuclear factor-kappaB (NF-κB), i.e., pyrrolidine dithiocarbamate and parthenolide, abrogated the stimulatory effect of poly (I:C) on the production of VEGF and IL-8 in RA FLS.

CONCLUSIONS

Our results suggest that the activation of TLR3 in RA FLS promotes the production of proangiogenic factors, in a process that is mediated by the NF-κB signaling pathway. Therefore, targeting the TLR3 pathway may be a promising approach to preventing pathologic angiogenesis in RA.

Correlation between ANGPTL3 expression and tumor angiogenesis in hepatocellular carcinoma

AIM: To investigate the correlation between the expression of angiopoietin-like protein 3 (ANGPTL3) and tumor angiogenesis in hepatocellular carcinoma (HCC).

METHODS: The expression of ANGPTL3 and VEGF proteins in 96 HCC specimens and matched tumor-adjacent specimens was detected by immunohistochemistry and Western blot. Immunohistochemical staining for CD34 was performed in the above specimens to evaluate microvessel density (MVD).

RESULTS: The positive rates of ANGPTL3 and VEGF expression in HCC were significantly higher than that in tumor-adjacent tissue (62.50% vs 32.29%; 81.25% vs 29.17%, both P < 0.05). Active angiogenesis was detected in HCC compared to tumor-adjacent tissue (67.71% vs 31.25%, P < 0.05). Tumor angiogenesis was related with ANGPTL3 expression in HCC. The expression of ANGPTL3 and VEGF protein was significantly up-regulated in HCC compared with matched tumor-adjacent noncancerous tissue.

CONCLUSION: High expression of ANGPTL3 is associated with tumor angiogenesis in HCC.

Oxymatrine down-regulates VEGF expression in human pancreatic carcinoma SW1990 cells

AIM: To observe the influence of oxymatrine (OM) treatment on vascular endothelial growth factor (VEGF) expression in human pancreatic carcinoma SW1990 cells and to assess the mechanism behind the cytotoxicity of OM against SW1990 cells.

METHODS: Cultured SW1990 cells were divided into two groups: control group and OM group. The OM group was further divided into three subgroups and treated with 1, 2 and 4 g/L OM, respectively. The mRNA and protein expression of VEGF in SW1990 cells was analyzed by real-time polymerase chain reaction (RT-PCR) and Western blot, respectively. The changes in the cytotoxicity of OM against SW1990 cells were assessed by MTT assay. The effect of OM on the invasiveness of SW1990 cells was analyzed using cell invasion assay kit.

RESULTS: The expression levels of VEGF mRNA in SW1990 cells were significantly lower in the three OM subgroups than in the control group (0.648 ± 0.043, 0.395 ± 0.012, 0.317 ± 0.031 vs 0.889 ± 0.028, all P < 0.05). Similar results were obtained for the protein expression of VEGF (1.668 ± 0.212, 1.523 ± 0.345, 1.388 ± 0.187 vs 1.876 ± 0.327, all P < 0.05). The invasion of SW1990 cells in the OM subgroups was markedly lower than that in the control group (325 ± 64.43, 206 ± 84.76, 124 ± 46.78 vs 498 ± 78.54, all P < 0.05).

CONCLUSION: OM is able to reduce the invasion of SW1990 cells possibly by down-regulating the expression of VEGF.

Clinical significance of VEGF expression in gastric cancer

AIM: To investigate the correlation between the expression of vascular endothelial growth factor (VEGF) protein and clinicopathological characteristics of gastric cancer.

METHODS: The surgical specimens from 775 patients with gastric cancer who were treated at Fuzhou General Hospital of Nanjing Military Command of Chinese PLA were used in this study. VEGF protein expression in these specimens was examined by immunohistochemistry.

RESULTS: The rate of VEGF protein overexpression was 25.42% (197/775). VEGF protein overexpression was associated with depth of invasion, lymph node metastasis and distant metastasis (all P < 0.05), but not with sex, age, tumor site, TNM stage, histopathologic type and differentiation (all P > 0.05). Multivariate analysis demonstrated that depth of invasion, lymph node metastasis and distant metastasis were significant predictors of VEGF protein overexpression in gastric cancer (all P < 0.05).

CONCLUSION: Detection of VEGF protein expression may be used to assess the malignant biological behavior and prognosis of gastric cancer.

Relation of the expression of cyclooxygenase-2 in colorectal adenomas and adenocarcinomas to angiogenesis and prognosis

Purpose

Recent studies have shown that cyclooxygenase (COX)-2 may be involved in tumor growth, invasion and apoptosis in various carcinomas. Vascular endothelial growth factor (VEGF) has a potent angiogenic activity, and COX-2 promotes angiogenesis by modulating angiogenic factors, including VEGF. Endothelial growth factor receptor (EGFR) is considered as a factor of cell growth, maturation and cell death. The current study was designed to investigate the possible roles of COX-2 in colorectal tumor progression and angiogenesis.

Methods

Fifty colorectal adenomas and forty adenocarcinomas were investigated by using immunohistochemical staining for COX-2, VEGF and EGFR. The correlations of COX-2, VEGF and EGFR with the grade of dysplasia, the size of the adenoma, and various clinicopathologic factors were studied.

Results

The expressions of COX-2, VEGF and EGFR were each significantly correlated with carcinomatous transformation, and the expressions of COX-2 and VEGF were significantly correlated. COX-2 and EGFR showed correlations with adenomas rather than adenocarcinomas. However, no correlations of COX-2, VEGF and EGFR expression to other clinicopathologic factors, except tumor size in EGFR expression, were detected.

Conclusion

These results suggest that COX-2 may play an important role in carcinogenesis through interaction with VEGF and EGFR in human colorectal cancer.

Role of the vascular endothelial growth factor signaling pathway in tumor growth and angiogenesis

New blood vessel formation (angiogenesis) is a fundamental event in the process of tumor growth and metastatic dissemination. Hence, the molecular basis of tumor angiogenesis has been of keen interest in the field of cancer research. The vascular endothelial growth factor (VEGF) signaling pathway is well established as one of the key regulators of this process. The VEGF/VEGF-receptor axis is composed of multiple ligands and receptors with overlapping and distinct ligand-receptor binding specificities, cell-type expression, and function. Activation of the VEGF signaling pathway triggers a network of signaling processes that promote endothelial cell growth, migration, and survival from pre-existing vasculature. In addition, VEGF-mediated vessel permeability has been associated with malignant effusions. More recently, an important role of VEGF has emerged in mobilization of endothelial progenitor cells from the bone marrow to distant site neovascularization. The well-established role of VEGF in promoting tumor angiogenesis and the pathogenesis of human cancers has led to the rational design and development of reagents that selectively target this pathway. Studies with various anti-VEGF/VEGFR therapies have shown that these reagents can potently inhibit angiogenesis and tumor growth in preclinical models.

Lymphangiogenesis: A new player in cancer progression

Lymph node metastasis is the hallmark of colon cancer progression, and is considered one of the most important prognostic factors. Recently, there has been growing evidence that tumor lymphangiogenesis (formation of new lymphatic vessels) plays an important role in this process. Here, we review the latest findings of the role of lymphangiogenesis in colorectal cancer progression, and discuss its clinical application as a biomarker and target for new therapy. Understanding the molecular pathways that regulate lymphangiogenesis is mandatory to pave the way for the development of new therapies for cancer. In the future, tailored treatments consisting of combinations of chemotherapy, other targeted therapies, and anti-lymphangiogenesis agents will hopefully improve patient outcomes. This progression to the clinic must be guided by new avenues of research, such as the identification of biomarkers that predict response to treatment.

CFH, VEGF, and PEDF genotypes and the response to intravitreous injection of bevacizumab for the treatment of age-related macular degeneration

We determined whether there is an association between complement factor H (CFH), high-temperature requirement A-1 (HTRA1), vascular endothelial growth factor (VEGF), and pigment epithelium-derived factor (PEDF) genotypes and the response to treatment with a single intravitreous injection of bevacizumab for age-related macular degeneration (AMD). Eighty-three patients with exudative AMD treated by bevacizumab injection were genotyped for three single nucleotide polymorphisms (SNPs; rs800292, rs1061170, rs1410996) in the CFH gene, a rs11200638-SNP in the HTRA1 gene, three SNPs (rs699947, rs1570360, rs2010963) in the VEGF gene, and four SNPs (rs12150053, rs12948385, rs9913583, rs1136287) in the PEDF gene using a TaqMan assay. The CT genotype (heterozygous) of CFH-rs1061170 was more frequently represented in nonresponders in vision than TT genotypes (nonrisk allele homozygous) at the time points of 1 and 3 months, while there was no CC genotype (risk allele homozygous) in our study cohort (p = 7.66 × 10(-3), 7.83 × 10(-3), respectively). VEGF-rs699947 was also associated with vision changes at 1 month and PEDF-rs1136287 at 3 months (p = 5.11 × 10(-3), 2.05 × 10(-2), respectively). These variants may be utilized for genetic biomarkers to estimate visual outcomes in the response to intravitreal bevacizumab treatment for AMD.

Clinical value of inhibition of vascular endothelial growth factor in primary hepatocellular carcinoma after transcatheter arterial chemoembolization

Vascular endothelial growth factor (VEGF) is a well-known potent angiogenic factor that correlates with tumor invasion and metastasis. Primary hepatocellular carcinoma (PHC) is a common highly malignant vascular tumor with a very high mortality. Angiogenesis is considered to be important for PHC progression. Transarterial chemoembolization (TACE) has been proved to be effective for unresectable PHC. This paper aims to make a literature review of the recent advances in understanding the clinical value of inhibition of VEGF in PHC after interventional therapy.

Hypoxia-inducible factor and vascular endothelial growth factor in the neuroretina and retinal blood vessels after retinal ischemia

Retinal ischemia arises from circulatory failure. As the retinal blood vessels are key organs in circulatory failure, our aim was to study the retinal vasculature separately from the neuroretina to elucidate the role of hypoxia-inducible factor (HIF) 1α and 1β and vascular endothelial growth factor (VEGF) in retinal ischemia. Retinal ischemia was induced in porcine eyes by applying an intraocular pressure, followed by 12 h of reperfusion. HIF-1α mRNA expression was not affected by ischemia, while immunofluorescence staining was higher after ischemia in the neuroretina. HIF-1β immunoreactivity and mRNA expression were unaffected. VEGF protein levels in the vitreous humor and VEGF staining in the neuroretina were more pronounced in eyes subjected to ischemia than in the sham eyes. VEGF may be activated downstream of HIF-1 and is known to stimulate retinal neovascularization, which causes sight-threatening complications. These results emphasize the need for pharmacological treatment to block the HIF and VEGF signaling pathways in retinal ischemia.