Angiopoietin 1 (Ang-1), angiopoietin 2 (Ang-2) and Tie-2 (a receptor tyrosine kinase) concentrations in peripheral blood of patients with thyroid cancers

Urinary Exosomal Tissue TIMP and Angiopoietin-1 Are Preoperative Novel Biomarkers of Well-Differentiated Thyroid Cancer

Finding non-invasive and sensitive biomarkers for early screening of high-risk patients remains important in clinical practice. A higher concentration of urine exosomal thyroglobulin protein was found in late-stage patients with thyroid carcinoma compared to those with early stage in our previous study. This prospective study aims to find new prognostic biomarkers before surgery for decision-making with this platform. We enrolled patients newly diagnosed with papillary and follicular cancer from 2017 to 2018. Preoperative urine samples were collected and the exosomal proteins were analyzed. The association of the concentration of urine exosomal proteins with lymph node metastasis and MACIS score (metastasis, age, completeness of resection, invasion, and size) was analyzed with multiple logistic regression. In total, 21 patients were included, with a mean age of 51.29 ± 10.29 years and a majority of female patients (85.71%). The concentration of urine exosomal TIMP (tissue inhibitor of metalloproteinase) was significantly higher in patients with lymph node metastasis (p = 0.01). Multiple logistic regression analysis showed association of urine exosomal TIMP (adjusted odds ratio (aOR): 3.09, 95% confidence interval (CI): 0.99-9.6, p = 0.052), angiopoietin-1 (aOR: 2.24, 95% CI: 0.97-5.15, p = 0.058) with lymph node metastasis. However, no association was noted between MACIS score and various urine exosomal protein candidates. Preoperative urine exosomal data could suggest certain peptides having the potential as prognostic indicators for screening patients with high-risk before surgery. Further study with a large cohort and long follow-up is needed to identify the application of urine exosomal proteins on prognostic prediction.

Microvessel density in differentiated thyroid carcinoma: A systematic review and meta-analysis

BACKGROUND

Microvessel density (MVD) has been proposed as a direct quantification method of tumor neovascularization. However, the current literature regarding the role of MVD in differentiated thyroid carcinoma (DTC) remains inconclusive.

AIM

To appraise the effect of tumoral MVD on the survival of patients with DTC.

METHODS

This meta-analysis was based on the PRISMA guidelines and the Cochrane Handbook for Systematic Reviews of Interventions. The electronic databases Medline, Web of Science, and Scopus were systematically screened. A fixed-effects or random-effects model was used, according to the Cochran Q test. The data were then extracted and assessed on the basis of the Reference Citation Analysis (https://www.referencecitationanalysis.com/).

RESULTS

A total of nine studies were included in the present study. Superiority of low MVD tumors in terms of 10-year disease free survival (OR: 0.21, 95%CI: 0.08–0.53) was recorded. Lowly vascularized thyroid cancers had a lower recurrence rate (OR: 13.66, 95%CI: 3.03–61.48). Moreover, relapsing tumors [weighed mean difference (WMD): 11.92, 95%CI: 6.32–17.52] or malignancies with regional lymph node involvement (WMD: 8.53, 95%CI: 0.04–17.02) presented with higher tumoral MVD values.

CONCLUSION

MVD significantly correlates with the survival outcomes of thyroid cancer patients. However, considering several study limitations, further prospective studies of higher methodological and quality level are required.

Serum angiopoietin-2 levels in dogs with splenic haemangiosarcoma, haemangioma, and splenitis

Haemangioma (HA) and haemangiosarcoma (HSA) are among the most common splenic neoplasms in dogs. The survival time in splenic HSA is short, probably due to the lack of proper biological markers allowing early detection. We investigated the serum angiopoietin-2 (Ang-2) concentrations in 9 healthy dogs and 40 dogs with abnormal splenic masses. The Ang-2 concentration differences were further compared in healthy dogs, dogs with splenitis, splenic HA and HSA. The results showed that the Ang-2 level in healthy dogs was significantly lower than in the splenitis and splenic HA cases. Moreover, the Ang-2 level was significantly higher in splenic HA than in splenic HSA. Conversely, no significant differences in Ang-2 level were recorded between healthy and splenic HSA dogs, and between splenitis and splenic neoplasms (HA and HSA). No significant correlations were observed between the Ang-2 level and (i) the clinical stage, (ii) histological growth pattern, and (iii) median survival time of splenic HSA dogs. In conclusion, serum Ang-2 concentration is a potentially useful biological marker for the discrimination of dogs with splenitis and splenic HA, as well as for the differentiation of splenic HA from its malignant form, HSA.

Identification of serum biomarker panel to differentiate malignant from benign thyroid nodules using multiplex bead assay

BACKGROUND

The challenging target in the workup of thyroid nodule(s) is to exclude or diagnose thyroid cancer efficiently prior to surgical intervention. The present work studied a panel of eight serum biomarkers to differentiate benign from malignant thyroid nodules, aiming at reducing unnecessary thyroidectomy performed for inconclusive preoperative fine needle aspiration cytology. Serum interleukin-5 (IL-5), interleukin-8 (IL-8), hepatocyte growth factor (HGF), epidermal growth factor (EGF), angiopietin (Ang1), nonokine induced by interferon gamma (MIG), galectin (Gal-3), and vitamin D-binding protein (VDRP) were quantified by multiplex bead assay using Luminex xMAP technology. The study was conducted on 60 subjects of three groups (20 each; healthy controls, benign thyroid nodule, and malignant thyroid nodule).

RESULTS

Significant increase of the following biomarkers in the malignant group compared to the benign group was found; IL-8: 29.7 vs 8.75 pg/ml, p < 0.001, EGF: 128.7 vs 6.72 pg/ml, p < 0.001, HGF: 173.2 vs 112.2 pg/ml, p = 0.012, MIG: 776.7 vs 438 pg/ml, p = 0.023, and Ang-1: 95016 vs 33327.5 pg/ml, p = 0.014. No significant differences were detected for IL-5, Gal-3, and VDBP. Serum IL-8 and EGF showed the highest diagnostic performance individually with area under the curve (AUC) 0.849 and 0.848, respectively. The combined biomarker panels of IL-8 and EGF and IL-8, EGF, and MIG have reached a sensitivity and specificity of 95% and 65%, respectively, with a negative predictive value of 92.9%.

CONCLUSIONS

Serum IL-8 and EGF individually or the combined biomarker panel of IL-8, EGF, and MIG are promising tests that can help to exclude malignancy in thyroid nodule workup.

High Expression of Angiopoietin-1 is Associated with Lymph Node Metastasis and Invasiveness of Papillary Thyroid Carcinoma

BACKGROUND

We investigated the expression of angiopoietins in patients with papillary thyroid carcinoma (PTC) and the role of angiopoietins as biomarkers predicting the aggressiveness of PTC.

METHODS

Expression of angiopoietins was evaluated by immunohistochemistry of tumor specimens from patients with PTC. We demonstrated potential correlations between expression of angiopoietins and clinicopathologic features.

RESULTS

High expression of Ang-1 was positively correlated with a tumor size >1 cm, capsular invasion, extrathyroid extension, lymphovascular invasion, lymph node metastasis, and recurrence (P < 0.05). Moreover, multivariate analysis revealed that high expression of Ang-1 was an independent risk factor for lymph node metastasis (P < 0.001, odds ratio [OR] = 62.113) and lymphovascular invasion (P = 0.027, OR 4.405). However, there was no significant correlation between Ang-2 and clinicopathologic features.

CONCLUSIONS

Our results suggest that Ang-1 can serve as a valuable prognostic biomarker for lymph node metastasis and invasiveness in patients with PTC.

Ang1/Tie2 induces cell proliferation and migration in human papillary thyroid carcinoma via the PI3K/AKT pathway

The angiopoietin 1 (Ang1)/angiopoietin receptor (Tie2) signaling pathway may have a notable role in the pathogenesis of inflammatory diseases. The abnormal expression of angiopoietin 1 and Tie2 has also been reported in various malignant tumors, including papillary thyroid carcinoma (PTC). However, the role and mechanism of the Ang1/Tie2 pathway in the progression of PTC remains unclear. Therefore, the aims of the present study were to clarify this. Significantly high expression levels of Ang1 and Tie2 were observed in PTC tissues and cell lines. Furthermore, MTT and wound-healing assays revealed that the Ang1-mediated stimulation of human PTC cells resulted in increased proliferation and migration. Conversely, the downregulation of Tie2 levels using short hairpin RNA targeted at Tie2 abrogated the Ang1-mediated effect on cell proliferation and migration. In studying the expression of phosphoinositide-3 kinase (PI3K)/RAC serine/threonine-protein kinase (Akt) pathway, the upregulation of Ang1/Tie2 was found to be associated with the activation of the PI3K/Akt pathway in PTC. In conclusion, the data from the present study indicated that the Ang1/Tie2 induces PTC oncogenesis via the PI3K/Akt pathway, providing novel insights into human PTC therapy.

Effect of Hua Yu Xiao Zheng decoction on the expression levels of vascular endothelial growth factor and angiopoietin-2 in rats with endometriosis

The aims of the present study were to investigate the effects of a traditional Chinese medicine, Hua Yu Xiao Zheng (HYXZ) decoction, on surgically induced endometriosis in a rat model and to determine the possible underlying regulatory mechanisms. A total of 108 female Sprague-Dawley rats were divided into the control group (n=12) and endometriosis group (EM group; n=96), in which endometriosis was surgically induced in model rats by autotransplantation of endometrial tissues and 72 rats survived. After 3 weeks, the EM model rats were randomly divided into four subgroups (n=18), including the untreated model group, and three groups administered 7, 14 or 21 g/kg HYXZ decoction. Following 28 days of treatment, the associated proteins and genes of ectopic endometrial tissues were analyzed using immunohistochemistry, western blotting and quantitative polymerase chain reaction to investigate the underlying mechanisms. Compared with the model group, the size of the endometriotic implants decreased significantly in the HYXZ-treated groups. Furthermore, the expression levels of vascular endothelial growth factor (VEGF) and angiopoietin-2 (Ang-2) were significantly decreased in HYXZ-treated groups compared with the model group. These results indicate that HYXZ affected the inhibition of angiogenesis and decreased the endometriotic implant volumes and histopathological scores. The effectiveness of HYXZ may be partially attributed to the decrease of VEGF and Ang-2 expression levels in the ectopic endometrium.

Prognostic Value of Serum Tumor Markers in Medullary Thyroid Cancer Patients Undergoing Vandetanib Treatment

Tyrosine kinase inhibitors (TKIs) such as vandetanib have shown clinical effectiveness in advanced medullary thyroid cancer (MTC). During TKI treatment, fluctuations in the tumor markers carcinoembryonic antigen (CEA) and calcitonin (CTN) are frequently observed. Their role for treatment monitoring and the decision-making process has not been fully elucidated yet.Twenty-one patients (male, 16, female, 5; mean age, 49 ± 13 years) with progressive MTC receiving vandetanib (300 mg orally per day) were considered. Tumor restaging was performed every 3 months including contrast-enhanced computed tomography (CT). Response was assessed according to recent criteria (Response Evaluation Criteria in Solid Tumors, RECIST 1.1). Additionally, CEA and CTN were measured at the day of CT imaging and alterations observed in tumor markers were compared to respective imaging findings (partial response, PR; stable disease, SD; progressive disease, PD).During long-term follow-up (510 ± 350 days [range, 97-1140 days]), CTN and CEA levels initially dropped in 71.4% and 61.9% of the patients followed by fluctuations in serum marker levels. A rise in CTN ≥39.5% between 2 subsequent measurements (defined by ROC analysis) had a sensitivity of 70.6% and a specificity of 83.2% in predicting PD with an accuracy of 82.0% (area under the curve (AUC), 0.76). Oscillations in CEA levels were not predictive for PD.Whereas tumor marker fluctuations in MTC patients undergoing TKI treatment are a frequent phenomenon, a significant rise in CTN ≥40% turns out to as an early indicator of tumor progression.

VEGF-D and A Preoperative Serum Levels Predict Nodal and Distant Metastases in Differentiated Thyroid Cancer Patients

BACKGROUND

Preoperative tumor aggressiveness biomarkers may help surgeons decide the extent of an operation. However, whether serum angiogenetic factors can be used to predict the prognosis of patients with differentiated thyroid cancer is still unclear.

METHODS

Seventy-six DTC patients were prospectively recruited. Preoperative serum samples were collected and measured for Tie-2, Ang-1, Ang-2, VEGF-A, and VEGF-D levels. The potential correlations between their serum levels and clinicopathologic features as well as their prognoses were analyzed.

RESULTS

Older age (>45 years old) and higher VEGF-A serum levels were independent predictors of extrathyroidal extension. The VEGF-D serum level was an independent factor for lymph node metastases and VEGF-A was an independent factor for distant metastases. None of these serum angiogenetic factors were significantly different between patients who were disease free and those with recurrences. The presence of lymph node metastases was the only independent factor for recurrence over the 2-year follow-up.

CONCLUSION

Preoperative serum VEGF-A and VEGF-D levels were significantly elevated in DTC patients with distant and lymph node metastases. These findings, when combined with other clinicopathological factors, may help in surgical decisions.

Development of a biosensor-based immunogenicity assay capable of blocking soluble drug target interference

As with other protein therapeutics, trebananib (AMG 386), an investigational peptide Fc-fusion protein ("peptibody") that inhibits angiogenesis by neutralizing the interaction of angiopoietin-1 (Ang1) and angiopoietin-2 (Ang2) with the Tie2 receptor, has the potential to trigger an immune response in cancer patients treated with the therapeutic. An electrochemiluminescence bridging anti-drug antibody (ADA) assay that was utilized to support early-phase clinical trials in the development of trebananib was found to lack adequate sensitivity and drug tolerance in later-phase clinical studies when higher doses of trebananib were administered. Therefore, we developed a surface plasmon resonance (SPR) immunoassay method utilizing a secondary confirmatory detector antibody (goat anti-human IgG F[ab']2) known to cross-react with human IgG and IgM to better assess the potential impact of immunogenicity on the pharmacokinetics, pharmacodynamics, and toxicity of trebananib. The SPR method was more sensitive than the electrochemiluminescence bridging assay because of signal amplification from the confirmatory binding of the detector antibody; drug tolerance was improved since antibody binding avidity does not affect detection on this platform. Despite the inability of the confirmatory detector antibody to bind angiopoietins in protein-free buffer, false-positive ADA results were generated from patient serum samples containing Ang1 and Ang2 through an apparently specific binding between the angiopoietins and the confirmatory detector antibody, likely mediated by the interaction of the angiopoietins with serum immunoglobulins. Addition to the sample diluent of a human antibody that specifically binds to Ang1 and Ang2 with high affinity resulted in a complete block of angiopoietin interference without affecting ADA detection. This biosensor-based assay provides a reliable method for assessing immunogenicity in phase 3 clinical trials.

Biomarkers for anti-angiogenic therapy in cancer

Angiogenesis, the development of new vessels from existing vasculature, plays a central role in tumor growth, survival, and progression. On the molecular level it is controlled by a number of pro- and anti-angiogenic cytokines, among which the vascular endothelial growth factors (VEGFs), together with their related VEGF-receptors, have an exceptional position. Therefore, the blockade of VEGF signaling in order to inhibit angiogenesis was deemed an attractive approach for cancer therapy and drugs interfering with the VEGF-ligands, the VEGF receptors, and the intracellular VEGF-mediated signal transduction were developed. Although promising in pre-clinical trials, VEGF-inhibition proved to be problematic in the clinical context. One major drawback was the generally high variability in patient response to anti-angiogenic drugs and the rapid development of therapy resistance, so that, in total, only moderate effects on progression-free and overall survival were observed. Biomarkers predicting the response to VEGF-inhibition might attenuate this problem and help to further individualize drug and dosage determination. Although up to now no definitive biomarker has been identified for this purpose, several candidates are currently under investigation. This review aims to give an overview of the recent developments in this field, focusing on the most prevalent tumor species.

Collaborating with the enemy: function of macrophages in the development of neoplastic disease

Due to the profile of released mediators (such as cytokines, chemokines, growth factors, etc.), neoplastic cells modulate the activity of immune system, directly affecting its components both locally and peripherally. This is reflected by the limited antineoplastic activity of the immune system (immunosuppressive effect), induction of tolerance to neoplastic antigens, and the promotion of processes associated with the proliferation of neoplastic tissue. Most of these responses are macrophages dependent, since these cells show proangiogenic properties, attenuate the adaptive response (anergization of naïve T lymphocytes, induction of Treg cell formation, polarization of immune response towards Th2, etc.), and support invasion and metastases formation. Tumor-associated macrophages (TAMs), a predominant component of leukocytic infiltrate, "cooperate" with the neoplastic tissue, leading to the intensified proliferation and the immune escape of the latter. This paper characterizes the function of macrophages in the development of neoplastic disease.

Serum biomarkers of papillary thyroid cancer

Objective

To identify serum biomarkers of papillary thyroid cancer.

Methods

Prospective analysis was performed of banked tumor and serum specimens from 99 patients with thyroid masses. Enzyme-linked immunosorbent assay (ELISA) was employed to measure levels of five serum proteins previously demonstrated to be up-regulated in papillary thyroid cancer (PTC): angiopoietin-1 (Ang-1), cytokeratin 19 (CK-19), tissue inhibitor of metalloproteinase-1 (TIMP-1), chitinase 3 like-1 (YKL-40), and galectin-3 (GAL-3). Serum levels were compared between patients with PTC and those with benign tumors.

Results

A total of 99 patients were enrolled in the study (27 men, 72 women), with a median age of 54 years. Forty-three patients had PTC and 58 cases were benign tumors. There were no statistically significant differences when comparing all five different biomarkers between PTC and other benign thyroid tumors. The p-values were 0.94, 0.48, 0.72, 0.48, and 0.90 for YKL-40, Gal-3, CK19, TIMP-1, and Ang-1, respectively.

Conclusion

Serum levels of four of the five proteins were elevated in patients with thyroid masses relative to normal values. However, the difference between benign and PTC was not significant. Two of the markers (Gal-3 & TIMP-1) displayed a greater potential difference, which may warrant further investigation. This study suggests that other serum markers should be sought. This is the first study to investigate potential serum biomarkers based on over-expressed proteins in thyroid cancer versus benign pathology.

Vascular endothelial growth factors and angiopoietins in presentations and prognosis of papillary thyroid carcinoma

AIMS

Angiogenesis from thyroid cancer cell plays the important roles in post-surgical persistent, recurrent, and metastatic papillary thyroid cancer (PTC). This study is to investigate the expression of angiopoietin-1 (Ang-1), angiopoietin-2 (Ang-2), Tek/Tie-2 receptor, and vascular endothelial growth factors (VEGF) in normal, benign thyroid tissues and different stage of PTC. We expect angiogenetic factors are important in the presentation of local-regional neck or distant metastases in PTC.

MATERIALS AND RESULTS

A total of 101 tissues from the subjects underwent thyroidectomy were enrolled in the study. There were 22 control and 79 thyroid cancer patients in different TNM stagings were collected. Ang-1 illustrated highest mean immunostaining score in metastatic group. Comparing with normal and benign thyroid tissues, thyroid cancer tissues illustrated significantly high expression of three angiogenetic factors and Tie-2 receptor. Of the PTC, significantly high expression of three angiogenetic factors and Tie-2 receptor were illustrated in recurrent cases. VEGF showed statistical difference in disease-free cancer mortality, and recurrent groups.

CONCLUSIONS

Immunochemical staining illustrated VEGF, Ang-1, Ang-2 expression in PTC tissues related to clinical staging; however, we need more information concerning these factors with long-term follow-up results.

Computational analysis of tissue-specific gene networks: application to murine retinal functional studies

MOTIVATION

The vertebrate retina is a complex neuronal tissue, and its development, normal functioning and response to injury and disease is subject to a variety of genetic factors. To understand better the regulatory and functional relationships between the genes expressed within the retina, we constructed an interactive gene network of the mouse retina by applying a Bayesian statistics approach to information derived from a variety of gene expression, protein-protein interaction and gene ontology annotation databases.

RESULTS

The network contains 673 retina-related genes. Most of them are obtained through manual literature-based curation, while the others are the genes preferentially expressed in the retina. These retina-related genes are linked by 3403 potential functional associations in the network. The prediction on the gene functional association using the Bayesian approach outperforms predictions using only one source of information. The network includes five major gene clusters, each enriched in different biological activities. There are several applications to this network. First, we identified approximately 50 hub genes that are predicted to play particularly important roles in the function of the retina. Some of them are not yet well studied. Second, we can predict novel gene functions using 'guilt by association' method. Third, we also predicted novel retinal disease-associated genes based on the network analysis.

AVAILABILITY

To provide easy access to the retinal network, we constructed an interactive web tool, named MoReNet, which is available at http://bioinfo.wilmer.jhu.edu/morenet/.

Serum levels of angiopoietin-1, angiopoietin-2, and their receptor tie-2 in patients with nonsmall cell lung cancer during chemotherapy

This pilot study was conducted to investigate the prognostic role and the effects of chemotherapy on serum angiogenic factors enzyme-linked immunosorbent assay consisting of Angiopoietin-1 and 2 (Ang-1, Ang-2) and their receptor Tie-2 in patients with advanced stage nonsmall cell lung cancer (NSCLC). Concentration of Ang-2 was higher in NSCLC (n= 40) than in healthy people (n= 15), whereas Ang-1 and Tie-2 were comparable. In our opinion determination of Ang-1, Ang-2, and Tie-2 concentrations have no clinical significance in the prognosis of the survival time in lung cancer and can not be used as a predictor of response to the chemotherapy.

Tie-2 is overexpressed by monocytes in autoimmune thyroid disorders and participates in their recruitment to the thyroid gland

CONTEXT

The angiopoietin/Tie system seems to have an important role in the pathogenesis of inflammatory diseases. Although Tie-2 is mainly expressed by endothelium, it is also detected in monocytes, which participate in the development of angiogenic and inflammatory phenomena.

AIM

The aim was to study the expression and function of Tie-2 and their ligands, angiopoietin-1 (Ang-1) and Ang-2, in thyroid glands and monocytes from patients with autoimmune thyroid disease (AITD).

DESIGN

We studied the expression of Tie-2, Ang-1, and Ang-2 by immunohistochemical techniques in surgical thyroid tissues from 17 patients with Graves' disease, 8 with Hashimoto's thyroiditis, and 3 healthy glands. In addition, we explored the expression and function of Tie-2 in peripheral blood monocytes from 17 patients with Graves' disease, 11 with Hashimoto's thyroiditis, and 14 healthy controls.

RESULTS

We found that the expression of Ang-1, Ang-2, and Tie-2 was up-regulated in thyroid glands from AITD patients. Flow cytometry, immunofluorescence, ELISA, and RT-PCR analyses confirmed the synthesis and release of Ang-1, Ang-2, and Tie-2 by thyroid follicular cells (TFC) from AITD patients. In addition, these patients showed increased levels of Tie-2(+) monocytes in the peripheral blood, which exhibited an enhanced chemotactic response to Ang-2 or autologous TFC.

CONCLUSIONS

Our data suggest that the Ang/Tie-2 system, through the participation of blood vessels, inflammatory cells, and TFC, may have an important role in the recruitment of monocytes to the thyroid gland and the pathogenesis of the tissue damage seen in AITD.

Preoperative serum angiopoietin-2 levels correlate with lymph node status in patients with early gastric cancer

BACKGROUND

Lymph node metastasis is the most important factor to consider when deciding on the modality of resection in patients with early gastric cancer. The aim of the present study was to assess the relationship between preoperative serum angiopoietin-2, a lymphangiogenic growth factor, and lymph node metastasis in patients with early gastric cancer.

METHODS

A total of 62 preoperative serum samples from patients diagnosed with early gastric adenocarcinoma, and 30 serum samples from healthy donors were obtained. The serum levels of angiopoietin-2 (Ang-2) were quantified by immunoassay. Intra- and peritumor lymphatic vessel density (I-LVD and P-LVD) were counted after immunohistochemical staining. The relationship between the serum Ang-2 levels and other prognostic variables (tumor size, histological type, depth of tumor invasion, I-LDV, P-LDV, presence of lymph node involvement, and distant metastasis) were then examined by univariate and multivariate linear regression analyses.

RESULTS

The median serum levels of Ang-2 in patients were higher than those of healthy controls [311.1 ng/mL, interquartile range (IQR) 256.7-311.1 ng/mL versus 286.5 ng/mL, IQR 226.9-286.5 ng/mL; Mann-Whitney test, P = 0.016]. Eight patients had metastatic lymph nodes; the Ang-2 levels from the patients with metastatic lymph nodes were higher than from those with negative lymph nodes (297.5 ng/mL, IQR 251.1-385.8 ng/mL versus 416.0 ng/mL, IQR 337.1-485.5 ng/mL; Mann-Whitney test, P = 0.019). Elevated serum Ang-2 levels were associated with positive lymph node involvement and this finding was significant on univariate (P = 0.008) and multivariate logistic regression analysis (P = 0.011).

CONCLUSION

Serum Ang-2 levels were clinically useful markers for lymph node metastasis in patients with early gastric cancer.

Serum angiopoietin-1 as a prognostic marker in resected early stage lung cancer

PURPOSE

We evaluated the clinical significance of angiopoietins and vascular endothelial growth factor (VEGF) in patients with resected early stage lung cancer.

PATIENTS AND METHODS

The study enrolled 101 patients with completely resected non-small cell lung cancer (NSCLC) of stage I or II, along with 70 healthy volunteers. Serum concentrations of angiopoietin-1, angiopoietin-2, and VEGF were measured with an ELISA. Immunohistochemical expression of angiopoietin-1 was compared with the microvessel density on the lung cancer tissues.

RESULTS

The patients had lower serum angiopoietin-1 (32.1+/-9.9 ng/mL vs. 39.0+/-10.8 ng/mL, p<0.001), higher angiopoietin-2 (1949.2+/-1099.4 pg/mL vs. 1498.6+/-650.0 pg/mL, p<0.01), and higher VEGF (565.1+/-406.3 pg/mL vs. 404.6+/-254.8 pg/mL, p<0.01) levels than the controls. The angiopoietin-2 level was higher in stage II than in stage I patients (p<0.05). The levels of angiopoietin-1 (r=0.28) and angiopoietin-2 (r=0.36) each correlated with the VEGF level. Patients with a higher level of angiopoietin-1 (> or =31.2 ng/mL) had better disease-specific and relapse-free survival than those with a lower angiopoietin-1 level (<31.2 ng/mL). Angiopoietin-1 expression negatively correlated with the microvessel density.

CONCLUSION

Serum angiopoietin-1 is a potential marker for predicting postoperative survival and recurrence in patients with early stage NSCLC.

Multiplex analysis of cytokines as biomarkers that differentiate benign and malignant thyroid diseases

Thyroid cancer incidence is increasing, and its diagnosis can be challenging. Fine needle biopsy, the principal clinical tool to make a tissue diagnosis, leads to inconclusive diagnoses in up to 30% of the cases, leading to surgery. Advances in proteomics are improving abilities to diagnose malignant conditions using small samples of tissue or body fluids. We hypothesized that analysis of serum growth factors would uncover diagnostically informative differences between benign and malignant thyroid conditions. Using xMAP profiling, we evaluated concentrations of 19 cytokines, chemokines, and growth factors. We used sera from 23 patients with cancer (Malignant group), 24 patients with benign nodular thyroid disease (Benign group), and 23 healthy subjects (Normal group). In univariate analysis, five factors (epithelial growth factor, hepatocyte growth factor, Interleukins-5 and -8, and regulated upon activation, normally T-expressed and presumably secreted (RANTES) distinguished subjects with thyroid disease from the Normal group. In multivariate analysis, the set {Interleukin-8, hepatocyte growth factor, monocyte-induced γ interferon, interleukin-12 p40} achieved noteworthy discrimination between Benign and Malignant groups (area under the receiver operating characteristics curve was 0.81 (95% confidence interval: 0.65-0.90)). Multiplex panels of serum biomarkers may be promising tools to diagnose cancer in patients presenting with evidence of nodular thyroid disease.

Quantum dot self-assembly for protein detection with sub-picomolar sensitivity

A novel approach to sensitive and rapid antigen detection is described. In the presence of a specific antigen, quantum dot-antibody conjugates rapidly self-assemble into agglomerates that are typically more than 1 order of magnitude larger than their individual components. The size distribution of the agglomerated colloids depends on, among other things, the relative concentration of quantum dot conjugates and antigen molecules. Quantum dot agglomerates mediated by antigen recognition were characterized by measuring their light scattering and fluorescence characteristics in an unmodified flow cytometer. Protein antigens angiopoietin-2 and mouse IgG were detected to sub-picomolar concentrations using this method. This simple technique enables the potential simultaneous detection of multiple antigenic biomarkers directly from physiological media and could be used for early detection and frequent screening of cancers and other diseases.

Angiopoietin-1 targeted RNA interference suppresses angiogenesis and tumor growth of esophageal cancer

AIM: To determine the inhibitory effect of the adenovirus-based angiopoietin-1 (Ang-1) targeted small interfering RNA expression system (Ad/Ang-1si) on the expression of the Ang-1 gene, cell growth and apoptosis in human esophageal cancer cell line Eca109.

METHODS: siRNA-expressing adenovirus targeting Ang-1 gene was constructed using the Ad Easy System. Cultured Eca109 cells were transfected with Ad/Ang-1si (Eca109/Ang-1si), and Ad/si was used to infect Eca109 cells as control (Eca109/si). Ang-1 gene expression and concentration was determined with RT-PCR and ELISA, respectively. Human umbilical vein endothelial cell (HUVEC) migration and proliferation were analyzed. After s.c. injection into athymic nu/nu mice, the tumor growth, vessel density and apoptosis of each group was also determined.

RESULTS: HUVEC migration induced by conditioned medium from Ang-1si-transfected Eca109 cells was significantly less than that induced by conditioned medium from Eca109 cells and control adenovirus-transfected Eca109 cells. Furthermore, after s.c. injection into athymic nu/nu mice, the tumor growth and cell apoptosis of Ad/Ang-1si -expressing Eca109 cells was significantly lower than that of parental or control adenovirus-transfected cells. Vessel density assessed by CD31 immunohistochemical analysis and Ang-1 expression by RT-PCR were also decreased.

CONCLUSION: The targeting Ang-1 may provide a therapeutic option for esophageal cancer.

Targeting angiogenesis in pancreatic cancer: rationale and pitfalls

INTRODUCTION

Pancreatic ductal adenocarcinoma (PDAC) is a highly aggressive cancer responsible for over 20% of deaths due to gastrointestinal malignancies. PDAC is usually diagnosed at an advanced stage which, in part, helps to explain its high resistance to chemotherapy and radiotherapy. In addition, the cancer cells in PDAC have a high propensity to metastasize and to aberrantly express several key regulators of angiogenesis and invasion. Chemotherapy has only provided a modest impact on mean survival and often induces side effects. Targeting angiogenesis alone or in combination with other modalities should be investigated to determine if it may provide for increased survival.

MATERIALS AND METHODS

This review summarizes the alterations in PDAC that play a critical role in angiogenesis and provides an overview of current and therapeutic strategies that may be useful for targeting angiogenesis in this malignancy.