Clinical significance of determination of surrogate markers of angiogenesis in breast cancer

Signal-On Near-Infrared Photoelectrochemical Aptasensors for Sensing VEGF165 Based on Ionic Liquid-Functionalized Nd-MOF Nanorods and In-Site Formation of Gold Nanoparticles

The low photon energy and deep penetrating ability of near-infrared (NIR) light make it an ideal light source for a photoelectrochemical (PEC) immunosensing system. Absorption wavelengths of the metal-organic frameworks (MOFs) can be regulated by adjusting the metal ions and the conjugation degree of the ligands. Herein, an ionic liquid with a large conjugated structure was synthesized and was used as a ligand to coordinate with Nd ions to prepare Nd-MOF nanorods with a band gap of 1.26 eV. The Nd-MOF rods show a good photoabsorption property from 200 to 980 nm. A PEC platform was constructed by using Nd-MOF nanorods as the photoelectroactive element. A detachable double-stranded DNA labeled with alkaline phosphatase (ALP), which is specific to VEGF165, was immobilized onto the PEC sensing interface. After blocking unspecific active sites with bovine albumin, an NIR PEC aptasensing system was developed for VEGF165 detection. After being incubated in a mixture of VEGF165, l-ascorbic acid 2-phosphate (magnesium salt hydrate) (AAP), and chloroauric acid, the aptamers for VEGF165 were detached from the PEC aptasensing interface, thus resulting in the decrease of the charge-transfer resistance and the increase of the photocurrent response. The shedding of the aptamers also makes the ALP approach the electrode surface, thus catalyzing the reduction of AAP to produce ascorbic acid (AA). Subsequently, AA reduces in situ chloroauric acid to produce AuNPs on the Nd-MOF-based sensing interface. With the excellent conductivity and localized surface plasmon resonance effect, the AuNPs can accelerate the separation of electron-hole pairs generated from Nd-MOF nanorods, thus promoting the photoelectric conversion efficiency and achieving signal amplification. Under optimized conditions, the PEC responses were linearly related to the VEGF165 concentrations in the range of 0.01-100 ng mL^-1 and exhibit a low detection limit of 3.51 pg mL^-1 (S/N = 3). VEGF165 in human serum samples was detected by the NIR PEC aptasensor. Their concentrations were found to be well consistent with that obtained from ELISA. Furthermore, the PEC aptasensor demonstrated recoveries from 96.07 to 103.8%. The relative standard deviations were within 5%, indicating good accuracy and precision. The results further verify its practicability for clinical diagnosis.

Photoplethysmography for demarcation of cutaneous squamous cell carcinoma

A video processing algorithm designed to identify cancer suspicious skin areas is presented here. It is based on video recordings of squamous cell carcinoma in the skin. Squamous cell carcinoma is a common malignancy, normally treated by surgical removal. The surgeon should always balance sufficient tissue removal against unnecessary mutilation, and therefore methods for distinction of cancer boundaries are wanted. Squamous cell carcinoma has angiogenesis and increased blood supply. Remote photoplethysmography is an evolving technique for analysis of signal variations in video recordings in order to extract vital signs such as pulsation. We hypothesize that the remote photoplethysmography signal inside the area of a squamous cell carcinoma is significantly different from the surrounding healthy skin. Based on high speed video recordings of 13 patients with squamous cell carcinoma, we have examined temporal signal differences in cancer areas versus healthy skin areas. A significant difference in temporal signal changes between cancer areas and healthy areas was found. Our video processing algorithm showed promising results encouraging further investigation to clarify how detailed distinctions can be made.

Angiogenesis induction in breast cancer: A paracrine paradigm

Breast cancer is the most prevalent type of cancer among women globally. Angiogenesis contributes significantly to breast cancer progression and dissemination. Neovascularization is concurrent with the progression and growth of breast cancer. Breast cancer cells control angiogenesis by secreting pro-angiogenic factors like fibroblast growth factor, vascular endothelial growth factor, interleukin, transforming growth factor-β, platelet-derived growth factor and several others. These pro-angiogenic factors trigger neovascularization, and thereby lead to breast cancer development and metastasis. The hypoxia-inducible factor (HIF)-regulated angiogenesis cascade is a crucial underlying factor in breast cancer growth and metastasis. To that end, several efforts have been made to identify druggable targets within the HIF-angiogenesis components. However, escape pathways are a major hindrance for targeted therapies against angiogenesis. Thus, understanding the key factors that trigger breast cancer angiogenesis is critical in elucidating ways to inhibit breast cancer. The current review provides an overview of the key growth factors that trigger breast cancer angiogenesis.

Microvessel density as a prognostic indicator of prostate cancer: A systematic review and meta-analysis

The aim of this study is to evaluate prognostic and therapeutic implications of microvessel density (MVD) in the recurrence-free survival (RFS), disease-specific survival (DSS), and overall survival (OS) in prostate cancer (PCa). As of April 2019, EMBASE, PubMed, Cochrane Library, Science Direct/Elsevier, MEDLINE, and CNKI are used for systematic literature retrieval to investigate the correlation between MVD and PCa. Meta-analysis was performed using Review Manager and Stata software. Combined hazard ratio (HR) was identified with 95% confidence intervals (95% CI) in a random or fixed effects model. Thirteen studies were identified in this article. Of which, 8 studies analyzed for the recurrence-free survival (2,399 patients) demonstrated that MVD significantly elevated in the poor recurrence-free survival (HR 2.57, 95% CI 2.21–2.97). Other 2 eligible studies (330 patients) with 3 data sets for the MVD-OS analysis and the pooled HR (HR 1.70, 95% CI 1.27–2.28) suggested a weak risk of overall death rate in patients with high-MVD levels. The last 3 studies for disease-specific survival (220 patients) suggested that the association with high MVD and disease-specific survival may not have statistically significance (HR 1.32, 95% CI 0.49–3.56). This study suggests that high intratumoral MVD appears a significant progenitor for poor recurrence-free survival of PCa.

Liver and spleen transcriptome reveals that Oreochromis aureus under long-term salinity stress may cause excessive energy consumption and immune response

To investigate the physiological responses of Oreochromis aureus to salinity fluctuations at the molecular level. We used RNA-seq to explore the differentially expressed genes (DEGs) in the liver and spleen of O. aureus at 0, 3, 7 and 11 ppt (parts per thousand) salinity levels. Herein, De novo assembly generated 71,009 O. aureus unigenes, of which 34,607 were successfully mapped to the four major databases. A total of 120 shared DEGs were identified in liver and spleen transcripts, of which 83 were up-regulated and 37 were down-regulated. GO and KEGG analysis found a total of 26 significant pathways, mainly including energy metabolism, immune response, ion transporters and signal transduction. The trend module category of DEGs showed that the genes (e.g., FASN, ODC1, CD22, MRC, TRAV and SLC7 family) involved in the change-stable-change (1) and the constant-change categories (2) were highly sensitive to salinity fluctuations, which were of great value for further study. Based on these results, it would help provide basic data for fish salinity acclimation, and provide new insights into evolutionary response of fish to various aquatic environments in the long-term stress adaptation mechanism.

Prognostic value of microvessel density in stage II and III colon cancer patients: a retrospective cohort study

Background

Microvessel density (MVD), as a derived marker for angiogenesis, has been associated with poor outcome in several types of cancer. This study aimed to evaluate the prognostic value of MVD in stage II and III colon cancer and its relation to tumour-stroma-percentage (TSP) and expression of HIF1A and VEGFA.

Methods

Formalin-fixed paraffin-embedded (FFPE) colon cancer tissues were collected from 53 stage II and 54 (5-fluorouracil-treated) stage III patients. MVD was scored by digital morphometric analysis of CD31-stained whole tumour sections. TSP was scored using haematoxylin-eosin stained slides. Protein expression of HIF1A and VEGFA was determined by immunohistochemical evaluation of tissue microarrays.

Results

Median MVD was higher in stage III compared to stage II colon cancers (11.1% versus 5.6% CD31-positive tissue area, p < 0.001). High MVD in stage II patients tended to be associated with poor disease free survival (DFS) in univariate analysis (p = 0.056). In contrast, high MVD in 5FU-treated stage III patients was associated with better DFS (p = 0.006). Prognostic value for MVD was observed in multivariate analyses for both cancer stages.

Conclusions

MVD is an independent prognostic factor associated with poor DFS in stage II colon cancer patients, and with better DFS in stage III colon cancer patients treated with adjuvant chemotherapy.

Electronic supplementary material

The online version of this article (10.1186/s12876-019-1063-4) contains supplementary material, which is available to authorized users.

The roles and role-players in thyroid cancer angiogenesis

Thyroid cancer is the most prevalent endocrine cancer worldwide. Angiogenesis, the formation of new blood vessels, plays a pivotal role in the development and progression of tumors. Over the past years, cancer research has focused on the ability of tumors to induce newly formed blood vessel, because tumor growth and the process of cancer metastasis mainly depends on angiogenesis. Tumor neovascularization occurs following the imbalance between pro-angiogenic and anti-angiogenic factors until the tumor switches to an angiogenic phenotype. A number of signaling factors and receptors that are implicated in the regulation of angiogenesis have been identified and characterized; most notably, the vascular endothelial growth factors (VEGFs) family and their receptors, which are the main pro-angiogenic molecules during early development and in pathological conditions such as cancer. Although thyroid is a highly vascularized organ, angiogenic switch in tumors of this organ leads to the formation of a vast network of blood vessels that favors the dissemination of tumor cells to distant organs and results in deterioration of patient conditions. Accordingly, the identification of key angiogenic biomarkers for thyroid cancer can facilitate diagnosis, prognosis and clinical decision-making and also may help to discover targeting factors for effective cancer therapy as well as monitoring response to therapy. Hence, the main purposes of this review are to summarize the types and mechanisms of angiogenesis emphasizing the prominent factors implicated in thyroid cancer angiogenesis.

Stage-Dependent Expression of an Angiogenic Agent and Vascular Organization in Experimental Skin Tumor Development

Increased angiogenesis and expression of antibodies to vascular endothelial growth factor (VEGF), an angiogenic agent, have been shown in the tumor development of many tissues. Areas of skin expressing VEGF and total volume of vessels expressing laminin in the wall were measured in chemical carcinogen-exposed mice using CAS-200 morphometry apparatus having a sensitivity exceeding 99% and reproducibility exceeding 99%. The area of VEGF expression was increased in carcinogen-exposed skin, dysplasia and in well-differentiated squamous cell carcinomas, but decreased in squamous cell carcinomas with decreased degree of differentiation. The vessel volume increased prior to the formation of tumors in carcinogen-exposed skin as well as in highly malignant neoplasms. In well-differentiated squamous cell carcinomas with an expansive growth pattern, the vessels were parallel to the basal membrane, in moderately differentiated tumors the vessels were in the direction of tumor invasion, and in poorly differentiated tumors, active angiogenesis consisted of numerous, enlarged vessels within the tumor. This study showed increased VEGF expression and number of vessels occurring in early stages of skin tumor development, pointing to a role of angiogenesis in chemical risk assessment and in cancer prevention. Altered vessel structure and vessel arrangement were distinct in later stages of tumor growth and in malignant neoplasms, pointing to the utility of detailed vessel analysis in neoplasm characterization.

Different types of tumor vessels in breast cancer: morphology and clinical value

Angiogenesis is a key factor of tumor progression. Considering, that the tumor vessels are heterogeneous and differ in morphology and clinical significance, the purpose of this research was to study of the morphological features of tumor vessels and their relationship with the clinical characteristics and morphological features of breast cancer (BC). In this pilot study the tumor samples received from 59 patients with T1–T2 stages of ductal invasive carcinomas were included. The sections were stained with hematoxylin and eosin and immunohistochemically using antibodies to CD34. The morphological features and the number of different types of tumor vessels were assessed microscopically and were compared with grade, lymph node metastasis, hormone receptors, HER2/neu status and with the presence of tumor emboli in vessels (lymphovascular invasion). We identified the following types of tumor vessels in BC: the normal microvessels, the dilated capillaries of peritumoral stroma, the atypical dilated capillaries and the “cavitary” structures (CS) type-1 and type-2 relating to the “cavitary” type of angiogenesis that was described by us earlier. The number of dilated capillaries correlated with CS type-1 (p = 0.003), CS type-2 (p = 0.002), atypical dilated capillaries (p = 0.0008) and with lymphovascular invasion (p = 0.005); the presence of atypical dilated capillaries—with CS type-1 (p < 0.00001), CS type-2 (p = 0.00004), lymphovascular invasion (p = 0.0002) and with the tumor grade (p = 0.003); the number of CS type-1—with estrogen receptor (p = 0.002) and progesterone receptor (p = 0.002) status and with lymphovascular invasion (p = 0.004); the presence of CS type-2—with positive Her2/new status (p = 0.0002) and lymphovascular invasion (p = 0.01). The density of normal microvessels was not associated with other types of tumor vessels and with clinical characteristics of BC. These data indicate that varied types of tumor vessels are associated with different morphological characteristics of BC, such as hormone receptors and HER2/neu status, lymphovascular invasion. We believe that the atypical dilated capillaries are related to the “cavitary” type of angiogenesis. The strong correlations of lymphovascular invasion with CS type-1 and atypical dilated capillaries testify that the “cavitary” type of angiogenesis may play a significant role in the formation of tumor emboli in the vessels.

Tumor microvasculature characteristics studied by image analysis: histologically-driven angiogenic profile

Angiogenesis, a hallmark of cancer, has been studied to be a potential marker for diagnosis, prognosis and therapy in breast cancer. To evaluate tumor angiogenesis, histological assessment has been a common approach and counting tumor microvessels after visualizing them by immunohistochemistry has been in use for a long time. With recent advances in digital pathology and image analysis, other characteristics of tumor vasculature can also be evaluated. In this article we briefly review the potentials of image analysis in assessing tumor microvessel morphologically that might be helpful in defining a better angiogenesis marker than other common markers like vessel count.

Prognostic value of microvessel density in hepatocellular carcinoma patients: a meta-analysis

INTRODUCTION

The identification of microvessel density (MVD) in patients suffering from different types of cancer has become a hot point as an emerging and promising biomarker. The aim of the present study is to clarify the prognostic relevance of MVD in hepatocellular carcinoma (HCC).

METHODS

Relevant articles were screened in PubMed and EMBASE databases. Patients' clinical characteristics, overall survival (OS), disease/recurrence-free survival (DFS/RFS), and MVD levels were extracted for further analysis. The statistical analysis derived from the Kaplan-Meier survival curves was calculated indirectly with the methods developed by Parmar, Williamson, and Tierney. Multivariate Cox hazard regression analysis was used directly in Stata 11.0. The pooled hazard ratio (HR) and 95% confidence interval (CI) were calculated to evaluate the prognostic role of MVD in HCC.

RESULTS

Our online literature search identified 12 articles including a total of 1,138 HCC patients. Meta-analysis of all the included studies considering survival outcomes showed a positive correlation between poor prognosis and higher-MVD levels. The pooled HRs (and 95% CIs) for OS and DFS/RFS were respectively 2.08 [1.77-2.45] and 2.64 [2.12-3.29]. Subgroup analyses considering tumor stage (I-II/III-IV), tumor size (<5 cm/≥ 5 cm), differentiation (well/poor), or cirrhosis status (≥ 20%/<20%) were also conducted, and all the above analyses supported the prognostic role of MVD in HCC.

CONCLUSION

Our meta-analysis showed that the available evidence supports the proposition that MVD has a good predictive role in HCC, especially when the patients have late stage, large size, or poorly differentiated tumors.

The clinical impact of mean vessel size and solidity in breast carcinoma patients

Angiogenesis quantification, through vessel counting or area estimation in the most vascular part of the tumour, has been found to be of prognostic value across a range of carcinomas, breast cancer included. We have applied computer image analysis to quantify vascular properties pertaining to size, shape and spatial distributions in photographed fields of CD34 stained sections. Aided by a pilot (98 cases), seven parameters were selected and validated on a separate set from 293 breast cancer patients. Two new prognostic markers were identified through continuous cox regression with endpoints breast cancer specific survival and distant disease free survival: The average size of the vessels as measured by their perimeter (p = 0.003 and 0.004, respectively), and the average complexity of the vessel shapes measured by their solidity (p = 0.004 and 0.004). The Hazard ratios for the corresponding median-dichotomized markers were 2.28 (p = 0.005) and 1.89 (p = 0.016) for the mean perimeter and 1.80 (p = 0.041) and 1.55 (p = 0.095) for the shape complexity. The markers were associated with poor histologic type, high grade, necrosis, HR negativity, inflammation, and p53 expression (vessel size only). Both markers were found to strongly influence the prognostic properties of vascular invasion (VI) and disseminated tumour cells in the bone marrow. The latter being prognostic only in cases with large vessels (p = 0.004 and 0.043) or low complexity (p = 0.018 and 0.024), but not in the small or complex vessel groups (p>0.47). VI was significant in all groups, but showed greater hazard ratios for small and low complexity vessels (6.54-11.2) versus large and high complexity vessels (2.64-3.06). We find that not only the overall amount of produced vasculature in angiogenic hot-spots is of prognostic significance, but also the morphological appearance of the generated vessels, i.e. the size and shape of vessels in the studied hot spots.

EGFR and microvessel density in canine malignant mammary tumours

The epidermal growth factor receptor (EGFR) is a transmembrane tyrosine kinase receptor which has been shown to have an important role in human breast cancer. Its role appears to be associated with increased angiogenesis and metastasis. In order to clarify its role in canine mammary tumours (CMT), 61 malignant neoplasms were studied by using immunohistochemistry, comparing expression of EGFR, microvessel density (MVD) by CD31 immunolabelling and characteristics of tumour aggressiveness. High EGFR immunoexpression was statistically significantly associated with tumour size, tumour necrosis, mitotic grade, histological grade of malignancy and clinical stage. High CD31 immunoreactivity was statistically significantly associated with tubule formation, histological grade of malignancy and clinical stage. A positive correlation between EGFR and CD31 immunoexpression (r = 0.843; P < 0.001) was also observed. Results suggest that an over-expression of EGFR may contribute to increased angiogenesis and aggression in malignant CMT, presenting the possibility of using EGFR inhibitors in the context of metastatic disease treatment.

Mesenchymal stem cell-derived interleukin-6 and vascular endothelial growth factor promote breast cancer cell migration

Several different cytokines and growth factors secreted by mesenchymal stem cells (MSCs) have been hypothesized to play a role in breast cancer progression. By using a small panel of breast cancer cell lines (MCF-7, T47D, and SK-Br-3 cells), we analyzed the role of interleukin-6 (IL-6) and vascular endothelial growth factor A (VEGF) in the cross-talk between MSCs and breast cancer cells. We performed migration assays in which breast cancer cells were allowed to migrate in response to conditioned medium from MSCs (MSCs-CM), in absence or in presence of the anti-VEGF antibody bevacizumab or an anti-IL-6 antibody, alone or in combination. We found that anti-VEGF and anti-IL-6 antibodies inhibited the migration of breast cancer cells and that the combination had an higher inhibitory effect. We next evaluated the effects of recombinant VEGF and IL-6 proteins on breast cancer cell growth and migration. IL-6 and VEGF had not significant effects on the proliferation of breast carcinoma cells. In contrast, both VEGF and IL-6 significantly increased the ability to migrate of MCF-7, T47D and SK-Br-3 cells, with the combination showing a greater effect as compared with treatment with a single protein. The combination of VEGF and IL-6 produced in breast cancer cells a more significant and more persistent activation of MAPK, AKT, and p38MAPK intracellular signaling pathways. These results suggest that MSC-secreted IL-6 and VEGF may act as paracrine factors to sustain breast cancer cell migration.

Dynamic Contrast-Enhanced Magnetic Resonance Imaging (DCE-MRI) in Preclinical Studies of Antivascular Treatments

Antivascular treatments can either be antiangiogenic or targeting established tumour vasculature. These treatments affect the tumour microvasculature and microenvironment but may not change clinical measures like tumour volume and growth. In research on antivascular treatments, information on the tumour vasculature is therefore essential. Preclinical research is often used for optimization of antivascular drugs alone or in combined treatments. Dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) is an in vivo imaging method providing vascular information, which has become an important tool in both preclinical and clinical research. This review discusses common DCE-MRI imaging protocols and analysis methods and provides an overview of preclinical research on antivascular treatments utilizing DCE-MRI.

Selection of Clinically useful Angiogenesis-Related Biomarkers: An Update

Angiogenesis is a complex phenomenon that involves interaction between growth factors/cytokines and their receptors, and proteolytic enzymes and their inhibitors, which, in addition to and in accordance with their main roles, act together during this multistep process. cancer angiogenesis is specific, because the same factors that enable angiogenesis are involved in the process of carcinogenesis. the aim of this review was to analyze the current knowledge regarding the significance of selected biomarkers in cancer angiogenesis, with emphasis on their prognostic value in the circulation.

Vascular proliferation is a prognostic factor in breast cancer

Angiogenesis is important for the growth and spread of malignant tumors, and anti-angiogenesis treatment is currently being evaluated for breast cancer and other tumors. Although microvessel density is the most commonly used tissue-based marker of tumor associated angiogenesis, it has significant limitations and has not proven effective as a predictive factor in selecting patients for treatment. We here wanted to explore the significance of vascular endothelial cell proliferation in breast carcinoma. We examined microvessel proliferation in breast cancer by dual immunohistochemical staining, using the pan-endothelial marker Factor-VIII combined with proliferation of endothelial cells by Ki-67 expression, in three independent series of breast cancer, including a total of 499 patients and 141 events during follow-up. Common statistical tests of associations as well as univariate and multivariate regression analysis of patient survival were used. By counting vessels with actively proliferating endothelium, we show that microvascular proliferation is a significant predictor of disease progression in breast cancer, especially among high-grade and ER-negative tumors. Our findings indicate that this novel marker of active tumor angiogenesis might be of value in patient management and should be further studied in the context of patient selection for anti-angiogenesis treatment.

Angiocrine factors modulate tumor proliferation and motility through EphA2 repression of Slit2 tumor suppressor function in endothelium

It is well known that tumor-derived proangiogenic factors induce neovascularization to facilitate tumor growth and malignant progression. However, the concept of "angiocrine" signaling, in which signals produced by endothelial cells elicit tumor cell responses distinct from vessel function, has been proposed, yet remains underinvestigated. Here, we report that angiocrine factors secreted from endothelium regulate tumor growth and motility. We found that Slit2, which is negatively regulated by endothelial EphA2 receptor, is one such tumor suppressive angiocrine factor. Slit2 activity is elevated in EphA2-deficient endothelium. Blocking Slit activity restored angiocrine-induced tumor growth/motility, whereas elevated Slit2 impaired growth/motility. To translate our findings to human cancer, we analyzed EphA2 and Slit2 expression in human cancer. EphA2 expression inversely correlated with Slit2 in the vasculature of invasive human ductal carcinoma samples. Moreover, analysis of large breast tumor data sets revealed that Slit2 correlated positively with overall and recurrence-free survival, providing clinical validation for the tumor suppressor function for Slit2 in human breast cancer. Together, these data support a novel, clinically relevant mechanism through which EphA2 represses Slit2 expression in endothelium to facilitate angiocrine-mediated tumor growth and motility by blocking a tumor suppressive signal.

Antiangiogenic therapies in early-stage breast cancer

Angiogenesis, which is crucial for the growth and spread of cancer cells, has become an important target for antineoplastic therapies in a variety of malignant tumors. Vascular endothelial growth factor and its receptor promote formation of new blood vessels in tumors. Several drugs, most notably the monoclonal antibody bevacizumab, have been developed to inhibit this process. Clinical trials utilizing bevacizumab and other antiangiogenic drugs in metastatic breast cancer have demonstrated enhanced response rates and prolonged progression-free survival, though no overall survival benefit has been seen. Trials are now under way exploring the use of antiangiogenic agents in patients with early stage breast cancer. We performed a comprehensive review of the published literature (English language), US National Institutes of Health clinical trials registry (ClinicalTrials.gov), and established cooperative groups that revealed approximately 75 clinical trials, completed or ongoing, utilizing antiangiogenic drugs in early-stage breast cancer. A number of phase II trials in the neoadjuvant setting have reported preliminary results suggesting response rates similar to those seen with traditional anthracycline-plus-taxane combination regimens. Most of these early trials have not yet met any survival endpoints. Studies are also ongoing in the adjuvant setting, and these have not yet been reported. The toxicities associated with these agents are similar to those that have been reported in the metastatic trials. Most of these side effects are grade 1 or 2 and are easily manageable; however, there remain a small percentage of patients who sustain life-threatening vascular events, bleeding, or wound-healing complications. This number is significantly higher in patients receiving antiangiogenic drugs when compared with controls. While we eagerly await completion and results of this impressive portfolio of studies in early breast cancer with antiangiogenic agents, there is an urgent need for a more rational patient/antiangiogenic therapy selection with greater insight into predictive factors for toxicities, therapy efficacy, and clinical benefit.

Plasma VEGF levels in breast cancer patients with and without metastases

Vascular endothelial growth factor (VEGF) is a key mediator of angiogenesis since it stimulates the formation of new blood vessels. Basic fibroblast growth factor (bFGF) is related to the promotion of endothelial cells into tube-like structures, and it is therefore expected to promote angiogenesis with a greater potency than VEGF. VEGF and bFGF are considered to be biomarkers that predict treatment effectiveness. Elevated plasma VEGF and bFGF levels have been reported in a variety of different malignant tumors, and patients with metastatic disease have also been reported to present with higher serum VEGF and bFGF levels. Other studies have documented controversial results with respect to the prognostic and predictive value of the aforementioned biomarkers. This study aimed to determine the plasma VEGF and bFGF levels in breast cancer patients without metastatic disease compared with breast cancer patients with advanced metastatic disease. The study included 93 patients with breast cancer, 46 without recurrent disease (group A) and 47 with metastatic disease (group B), as well as 21 healthy individuals. The median age was 58 years (range 34-78) for group A and 59 years (range 37-75) for group B. All 93 patients underwent chemotherapy, adjuvant for group A, and adjuvant plus chemotherapy for group B patients with advanced disease. Plasma VEGF and bFGF levels were determined using a quantitative sandwich immunoassay, and samples were tested in triplicate (ELISA). The plasma levels of VEGF and bFGF varied greatly, i.e., from extremely low to extremely high in the two groups, as well as in the healthy individuals. No statistically significant difference was found between the two groups or between the patients and healthy individuals. Data of the present study therefore showed that VEGF and bFGF levels are not valuable biomarkers for predicting treatment outcome.

Tumor vascular permeability to a nanoprobe correlates to tumor-specific expression levels of angiogenic markers

Background

Vascular endothelial growth factor (VEGF) receptor-2 is the major mediator of the mitogenic, angiogenic, and vascular hyperpermeability effects of VEGF on breast tumors. Overexpression of VEGF and VEGF receptor-2 is associated with the degree of pathomorphosis of the tumor tissue and unfavorable prognosis. In this study, we demonstrate that non-invasive quantification of the degree of tumor vascular permeability to a nanoprobe correlates with the VEGF and its receptor levels and tumor growth.

Methodology/Principal Findings

We designed an imaging nanoprobe and a methodology to detect the intratumoral deposition of a 100 nm-scale nanoprobe using mammography allowing measurement of the tumor vascular permeability in a rat MAT B III breast tumor model. The tumor vascular permeability varied widely among the animals. Notably, the VEGF and VEGF receptor-2 gene expression of the tumors as measured by qRT-PCR displayed a strong correlation to the imaging-based measurements of vascular permeability to the 100 nm-scale nanoprobe. This is in good agreement with the fact that tumors with high angiogenic activity are expected to have more permeable blood vessels resulting in high intratumoral deposition of a nanoscale agent. In addition, we show that higher intratumoral deposition of the nanoprobe as imaged with mammography correlated to a faster tumor growth rate. This data suggest that vascular permeability scales to the tumor growth and that tumor vascular permeability can be a measure of underlying VEGF and VEGF receptor-2 expression in individual tumors.

Conclusions/Significance

This is the first demonstration, to our knowledge, that quantitative imaging of tumor vascular permeability to a nanoprobe represents a form of a surrogate, functional biomarker of underlying molecular markers of angiogenesis.

Immunostaining with D2-40 improves evaluation of lymphovascular invasion, but may not predict sentinel lymph node status in early breast cancer

Background

Sentinel lymph node (SLN) biopsy is a widely used diagnostic procedure in the management of early breast cancer. When SLN is free of metastasis, complete axillary dissection may be skipped for staging in clinically N0 patients, allowing a more conservative procedure. Histological tumor features that could reliably predict SLN status have not yet been established. Since the degree of tumor lymphangiogenesis and vascularization may theoretically be related to the risk of lymph node metastasis, we sought to evaluate the relationship between lymph vessel invasion (LVI), lymphatic microvascular density (LVD), microvascular density (MVD) and VEGF-A expression, with SLN status and other known adverse clinical risk factors.

Methods

Protein expression of D2–40, CD34, and VEGF-A was assessed by immunohistochemistry on paraffin-embedded sections of primary breast cancer specimens from 92 patients submitted to SLN investigation. The presence of LVI, the highest number of micro vessels stained for D2–40 and CD34, and the protein expression of VEGF-A were compared to SLN status, clinicopathological features and risk groups.

Results

LVI was detected in higher ratios by immunostaining with D2–40 (p < 0.0001), what would have changed the risk category from low to intermediate in four cases (4.3%). There was no association between LVI and other angiogenic parameters determined by immunohistochemistry with SLN macrometastases, clinical features or risk categories.

Conclusion

Assessment of LVI in breast carcinoma may be significantly increased by immunostaining with D2–40, but the clinical relevance of altering the risk category using this parameter may not be advocated according to our results, neither can the use of LVI and LVD as predictors of SLN macrometastasis in early breast cancer.

Following up tumour angiogenesis: from the basic laboratory to the clinic

Preceded by three decades of intense basic research on tumour angiogenesis, we are assisting to the translation of anti-antiangiogenic therapies as medical oncologists are increasingly using pioneering anti-angiogenic drugs in combination with standard treatments. While basic knowledge in the field of angiogenesis is reaching maturity and our level of understanding of the complex process of vessel development and growth in health and disease has been enriched at the molecular and cellular levels, the translation of this knowledge to the clinic is still in its infancy. Identifying the most suitable drugs, and the optimal dosage and schedule, as well as monitoring patients' responses to anti-angiogenic therapy, remain challenging issues that currently limit the benefit of this new therapeutic approach in cancer. This review will focus on a comprehensive description of the experimental assays in which angiogenesis research has been founded and how the different assays complement and provide relevant information for the task of characterising the angiogenic properties of diverse tumours, giving us a variety of tools to follow up tumour angiogenesis in research models. Following up tumour angiogenesis in patients and their response to antiangiogenic therapy is a more challenging task that will benefit in the near future from the use of non-invasive imaging methods as well as molecular and cellular biomarkers of angiogenesis suitable for clinical oncology. As both the design of the anti-angiogenic therapies and monitoring of the response are improved in the coming years to properly tailor them to the angiogenic profile of every patient, we hope to achieve increasing response and benefit of including antiangiogenic drugs as standard in cancer therapy.

Circulating and imaging markers for angiogenesis

Abundant preclinical and indirect clinical data have for several decades convincingly supported the notion that anti-angiogenesis is an effective strategy for the inhibition of tumor growth. The recent success achieved in patients with metastatic colon carcinoma using a neutralizing antibody directed against vascular endothelial growth factor (VEGF) has translated preclinical optimism into a clinical reality.With this transformation in the field of angiogenesis has come a need for reliable surrogate markers. A surrogate marker by definition serves as a substitute for the underlying process in question, and in the case of angiogenesis, microvessel density (usually in so-called "hot-spots") has until now been the most widely used parameter. However, this parameter is more akin to a static "snap-shot" and does not lend itself either to the dynamic in situ assessment of the status of the tumor microvasculature or to the molecular factors that regulate its growth and involution. This has led to an acute need for developing circulating and imaging markers of angiogenesis that can be monitored in vivo at repeated intervals in large number of patients with a variety of tumors in a non-invasive manner. Such markers of angiogenesis are the subject of this review.

Anti-angiogenic potential of CoenzymeQ10, riboflavin and niacin in breast cancer patients undergoing tamoxifen therapy

Tumour angiogenesis is a complex mechanism consisting of multi-step events including secretion or activation of angiogenic factors by tumour cells, activation of proteolytic enzymes, proliferation, migration and differentiation of endothelial cells. Both primary and metastatic tumours in the breast are dependent on angiogenesis. In the present study, 84 breast cancer patients were randomized to receive a daily supplement of CoQ(10) 100 mg, riboflavin 10 mg and niacin 50 mg (CoRN), one dosage per day along with tamoxifen (TAM) 10 mg twice a day. Serum pro-angiogenic levels were elevated in untreated breast cancer patients (Group II) and their levels were found to be reduced in breast cancer patients undergoing TAM therapy for more than 1 year (Group III). When these group III breast cancer patients were supplemented with CoRN for 45 days (Group IV) and 90 days (Group V) along with TAM, a further significant reduction in pro-angiogenic marker levels were observed. Supplementing CoRN to breast cancer patients has found to decrease the levels of pro-angiogenic factors and increase the levels of anti-angiogenic factors. A reduction in pro-angiogenic marker levels attributes to reduction in tumour burden and may suggest good prognosis and efficacy of the treatment, and might even offer protection from cancer metastases and recurrence.

Comparison of single- and dual-tracer pharmacokinetic modeling of dynamic contrast-enhanced MRI data using low, medium, and high molecular weight contrast agents

Pharmacokinetic parameters corresponding to perfused microvascular volume determined from dynamic contrast-enhanced (DCE) MRI data were compared to immunohistochemical measures of microvascular density (MVD) and perfused microvascular density. DCE MRI data from human mammary tumors (MDA-MB-435) implanted in nude mice using low (Gd-DTPA, MW approximately equal 0.6 kDa), medium (Gadomer-17, MW(eff) approximately equal 35 kDa), and high (PG-Gd-DTPA, MW approximately equal 220 kDa) molecular weight contrast agents were analyzed with single- and dual-tracer pharmacokinetic models. MVD values were determined by two manual counting methods, "hot spot" and summed region of interest (SROI). Pharmacokinetic parameters determined using the single-tracer model (Gd-DTPA [n = 15] and Gadomer-17 [n = 13]) did not correlate with MVD measures using either manual counting method. For dual-tracer studies (Gadomer-17/Gd-DTPA [n = 15] and PG-Gd-DTPA/Gd-DTPA [n = 13]), pharmacokinetic parameters demonstrated a statistically significant correlation with MVD determined by the SROI method, but not the "hot spot" method. Ten mice successfully underwent intravital FITC-labeled lectin perfusion with the hemisphere of highest lectin labeling correlating with pharmacokinetic parameter values in 9 of 10 tumors (single-tracer Gd-DTPA [n = 2], single-tracer Gadomer-17 [n = 3], and dual-tracer Gadomer-17/Gd-DTPA [n = 5]). This study demonstrates that dual-tracer DCE MRI studies yield pharmacokinetic parameters that correlate with immunohistochemical measures of MVD.

Prognostic significance of microvessel density and other variables in Japanese and British patients with primary invasive breast cancer

The purpose of this study is to investigate the associations of microvessel density (MVD) and other pathological variables with survival, and whether they accounted for survival differences between Japanese and British patients. One hundred seventy-three Japanese and 184 British patients were included in the study. British patients were significantly older (56.3±11.4 years vs 52.5±12.9 years; P<0.01) and had smaller tumours (2.2±1.3 vs 2.7±1.8 cm; P<0.01), which were more frequently oestrogen receptor positive (78.8 vs 57.2%, P<0.01), had more grade III tumours (29.9 vs 21.4%, P=0.04) and more infiltrating lobular carcinomas (13.6 vs 4.0%, P<0.01) and a higher MVD compared with Japanese patients (57.9±19.8 vs 53.2±18.6; P=0.01). However, no difference in the prevalence of lymph-node metastasis was found between them (39.1 vs 37.5%, P=0.75). Younger British patients (age <50 years) had the highest MVD compared with Japanese and older British patients (P<0.01). Japanese patients were proportionately more likely to receive chemotherapy than endocrine therapy (P<0.01). British patients had a significantly worse relapse-free survival and overall survival compared with Japanese patients, after statistical adjustment for variables (hazard ratio=2.1, 2.4, P<0.01, P<0.01, respectively), especially, in T2 stage, low MVD and older subgroup (HR: 3.6, 5.0; 3.1, 3.3; 3.2, 3.9, respectively), but only in ER negative cases (P=0.04, P=0.01, respectively). The present study shows that MVD contributes to the Japanese–British disparity in breast cancer. However, the MVD variability did not explain the survival differences between Japanese and British patients.

On the role of endothelin-converting enzyme-1 (ECE-1) and neprilysin in human breast cancer

Endothelin-1 (ET-1) and its receptors, ET(A)R and ET(B)R, are overexpressed in breast carcinomas. However, little is known about the relevance of endothelin-converting enzyme-1 (ECE-1) and ET-1 degrading neprilysin (NEP). In this study, expression of ECE-1 and NEP was determined in 600 breast cancer tissue samples by immunohistochemistry; staining results were correlated with clinicopathological parameters. For ECE-1 expression, we found a significant correlation with VEGF (P < 0.001) and ET(A)R expression (P = 0.048). While patients with ECE-1 overexpressing tumours had more frequent disease recurrence (P = 0.03), NEP overexpression correlated with improved disease-free survival (DFS) (P = 0.023) and less frequent metastasis (P = 0.046). Also, a decrease of NEP expression with malignant progression (G1-G3) was found. ECE-1 inhibition using the selective ECE-1 inhibitor RO 67-7447 in MCF-7 breast cancer cells led to a significantly decreased ET-1 expression and reduced cell invasiveness (54.3% of controls, P = 0.014). Our results indicate that overexpression of ECE-1 is associated with unfavourable outcome, whereas NEP positively influences survival. Thus, expression of ECE-1 and NEP may have prognostic relevance. Due to the anti-invasive effect of the selective ECE-1 inhibitor, targeting ECE-1 may represent an innovative option in future breast cancer therapy.

Ephrin-A1 facilitates mammary tumor metastasis through an angiogenesis-dependent mechanism mediated by EphA receptor and vascular endothelial growth factor in mice

Ephrin-A1, the prototypic ligand for EphA receptor tyrosine kinases, is overexpressed in vascularized tumors relative to normal tissue. Moreover, ephrin-A1-Fc fusion proteins induce endothelial cell sprouting, migration, and assembly in vitro, and s.c. vascular remodeling in vivo. Based on these data, we hypothesized that native, membrane-bound ephrin-A1 regulates tumor angiogenesis and progression. We tested this hypothesis using a transplantable mouse mammary tumor model. Small interfering RNA-mediated ephrin-A1 knockdown in metastatic mammary tumor cells significantly diminishes lung metastasis without affecting tumor volume, invasion, intravasation, or lung colonization upon i.v. injection in vivo. Ephrin-A1 knockdown reduced tumor-induced endothelial cell migration in vitro and microvascular density in vivo. Conversely, overexpression of ephrin-A1 in nonmetastatic mammary tumor cells elevated microvascular density and vascular recruitment. Overexpression of ephrin-A1 elevated wild-type but not EphA2-deficient endothelial cell migration toward tumor cells, suggesting that activation of EphA2 on endothelial cells is one mechanism by which ephrin-A1 regulates angiogenesis. Furthermore, ephrin-A1 knockdown diminished, whereas overexpression of ephrin-A1 elevated, vascular endothelial growth factor (VEGF) levels in tumor cell-conditioned medium, suggesting that ephrin-A1-mediated modulation of the VEGF pathway is another mechanism by which membrane-tethered ephrin-A1 regulates angiogenic responses from initially distant host endothelium. These data suggest that ephrin-A1 is a proangiogenic signal, regulating VEGF expression and facilitating angiogenesis-dependent metastatic spread.

Biomarkers in breast cancer

Breast cancer is one of the most frequently diagnosed cancers among women in the western world. Due to the aggressive behaviour of some specific types and the possibility of an early diagnosis, breast cancer has been constantly studied. Tumour size, histological type, cellular and nuclear characteristics, mitotic index, vascular invasion, hormonal receptors and axillary lymph node status are biomarkers routinely used. However, these parameters are not enough to predict the course of this disease. Molecular biology advances have made it possible to find new markers, which have already been incorporated to the clinical practice. Their ultimate goal is to reduce mortality by identifying women at risk for the development of this disease, help diagnosis, determine prognosis, detect recurrences, monitor and guide treatment, and in particular cancers they are suited for general screening. Tumour markers in breast cancer were ranked in categories reflecting their clinical utility, according to the American College of Pathologists.

This article focuses on traditional and new molecular markers stratifying them into categories and emphasizing their relevance in the routine evaluation of patients with breast cancer.

Expression and prognostic impact of the protein tyrosine phosphatases PRL-1, PRL-2, and PRL-3 in breast cancer

The aim of this study was to investigate the expression of the protein tyrosine phosphatases (PTP) PRL-1, PRL-2, and PRL-3 in human breast cancer and to evaluate its clinical and prognostic significance. PRL-PTP mRNA expression was examined in malignant (n=7) and nonmalignant (n=7) cryoconserved breast tissue samples as well as in eight breast cancer cell lines by RT–PCR. Furthermore, protein expression of PRL-3 was analysed semiquantitatively by immunohistochemistry in ductal breast carcinoma in situ (n=135) and invasive breast cancer (n=147) by use of tissue microarray technology (TMA). In 24 lymph node-positive patients we selected the corresponding lymph node metastases for analysis of PRL-3 expression, and a validation set (n=99) of invasive breast cancer samples was examined. Staining results were correlated with clinicopathological parameters and long-term follow-up. PRL-3 mRNA expression was significantly higher in malignant compared to benign breast tissue. For PRL-1 and PRL-2 expression no significant differences were observed. Staining of TMAs showed PRL-3 expression in 85.9% ductal carcinoma in situ and 75.5% invasive breast carcinomas. Analysis of survival parameters revealed a shorter disease-free survival (DFS) in patients with PRL-3-positive carcinomas, and in particular a significantly shorter DFS in nodal-positive patients with PRL-3 overexpressing tumours as compared to PRL-3-negative breast carcinomas (66±7 months (95% CI, 52–80) vs 97±9 months (95% CI, 79–115); P=0.032). Moreover, we found a more frequent expression of PRL-3 in lymph node metastases as compared to the primary tumours (91.7 vs 66.7%; P=0.033). Our results suggest that PRL-3 might serve as a novel prognostic factor in breast cancer, which may help to predict an adverse disease outcome.

Decreased Pigment Epithelium–Derived Factor Expression in Human Breast Cancer Progression

PURPOSE

The aim of this study was to correlate the expression of pigment epithelium-derived factor (PEDF), a potent endogenous antiangiogenic molecule, with severity and prognosis in breast cancer.

EXPERIMENTAL DESIGN

To investigate the gene expression profile of PEDF in human breast cancer in relation to a patient's clinical variables, we examined human breast cancer tissue (n = 119), background breast tissue (n = 33), and a range of cell lines for mRNA and protein levels of PEDF by using reverse transcription PCR, real-time quantitative PCR, immunohistochemistry, and ELISA.

RESULTS

By using reverse transcription PCR, real-time quantitative PCR, immunohistochemistry, and ELISA, PEDF expression was found to be dramatically decreased in breast cancer. An overall outlook for the patients inversely correlated with PEDF mRNA levels. Exogenous PEDF inhibits endothelial tubule formation induced by breast cancer cell-conditioned medium, in vitro.

CONCLUSION

These observations collectively support the hypothesis that a lack of PEDF expression is a potent factor for the enhancement of tumor growth and angiogenesis in breast cancer.

Angiogenesis and cancer: A cross-talk between basic science and clinical trials (the "do ut des" paradigm)

Angiogenesis plays a crucial role in facilitating tumor growth and the metastatic process, and it is the result of a dynamic balance between pro-angiogenic factors, like vascular endothelial growth factor (VEGF) and platelet-derived growth factor, and antiangiogenic factors, like thrombospondin-1 and angiostatin. Many drugs that target human tumors, like bevacizumab and some VEGF-receptor tyrosine-kinase inhibitors (e.g., BAY 43-9006, SU11248 and PTK787/ZK222584) have been studied in clinical trials, with favorable toxicity reports and encouraging results in advanced colorectal cancer, renal cell cancer, breast cancer and non-squamous non-small cell lung cancer, either combined with chemotherapy, or in monotherapy. Another potential approach to inhibiting angiogenesis is through metronomic chemotherapy (low doses of chemotherapy for long periods of time). This review describes the mechanisms of the angiogenic process and evaluates the recent data about antiangiogenic therapies in clinical trials.

Angiogenic molecule expression is downregulated in effusions from breast cancer patients

The objective of this study was to analyze site-related expression of angiogenic molecules in breast carcinoma, with the aim of characterizing phenotypic alterations along the clinical progression from primary tumor to pleural effusion. A total of 49 malignant pleural effusions and 68 corresponding solid tumors were studied for protein and mRNA expression of vascular endothelial growth factor (VEGF) and its receptor KDR, interleukin-8 (IL-8), basic fibroblast growth factor (bFGF) and the alphaV integrin subunit using immunohistochemistry, mRNA in situ hybridization (ISH) and reverse transcription polymerase chain reaction (RT-PCR). Expression was analyzed for possible association with mRNA expression of the Ets-1 and PEA3 transcription factors. The predictive value of angiogenic molecules, PEA3 and Ets-1, and clinical parameters was analyzed for 18 patients. ISH showed the presence of VEGF, IL-8 and bFGF mRNA in the majority of specimens, irrespective of anatomic site (p > 0.05). However, protein expression of IL-8 and bFGF was lower in effusions compared to primary tumors (p = 0.001 for IL-8, p < 0.001 for bFGF). Expression of alphaV integrin showed an opposite change, with higher level in effusions compared to primary tumors (p = 0.03). bFGF and alphaV integrin expression in effusions was also altered compared to lymph node metastases (p = 0.041 and p = 0.016, respectively). IL-8 and Ets-1 (p = 0.035) and VEGF and PEA3 (p = 0.026) mRNA was co-expressed in effusions. In univariate survival analysis, bFGF protein expression in effusions (p = 0.015), PEA3 mRNA expression in primary tumors (p = 0.02) and previous radiation therapy (p = 0.034) predicted shorter disease-free survival. PEA mRNA expression in primary tumors (p = 0.002) and previous chemotherapy (p = 0.048) predicted poor overall survival, with a similar trend for advanced disease stage at diagnosis (p = 0.05). Our data provide evidence regarding molecular changes that occur along the progression of breast carcinoma from primary tumor to effusion, and suggest altered requirement of angiogenic factors in body cavities. The poor disease-free survival for patients with bFGF-positive effusions suggests a role for this growth factor in mediating tumor survival rather than angiogenesis at this site.

Magnetic resonance imaging reveals functional diversity of the vasculature in benign and malignant breast lesions

BACKGROUND

Tumor perfusion through the microvascular network can be imaged noninvasively by dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI). The objective of the current study was to quantify the microvascular perfusion parameters in various human breast lesions and to determine whether they varied between benign lesions and malignancy and whether they were altered with increased invasiveness.

METHODS

Perfusion parameters in 22 benign fibrocystic changes, 15 ductal carcinomas in situ (DCIS), 30 infiltrating ductal carcinomas (IDC), and 22 fibroadenomas were measured using high-resolution DCE-MRI. Pixel-by-pixel image analysis yielded parametric images of two perfusion indicators: the influx transcapillary transfer constant (k(trans)) and the efflux transcapillary rate constant (k(ep)). Correlations of lesion type and perfusion parameters were calculated using Spearman correlation. Logistic regression analysis evaluated the best predictors of the kinetic parameters that differentiate between IDC and benign lesions.

RESULTS

The perfusion parameters exhibited a progressive increase from benign fibrocystic changes to DCIS and IDC, with a significant correlation between lesion type and the parameters' values (range of correlation coefficients, 0.56-0.76; P < 0.0001). In addition, k(trans) increased from low-grade DCIS to high-grade DCIS. Fibroadenomas were characterized uniquely by high k(trans) but low k(ep). Stepwise logistic regression selected k(trans) as the best predictor for distinguishing benign fibrocystic changes from IDC, yielding 93% sensitivity and 96% specificity.

CONCLUSIONS

The microvascular perfusion parameters in breast lesions were elevated with invasiveness. Quantification of these parameters using high-resolution DCE-MRI was helpful for differentiating between breast lesions and should improve breast carcinoma diagnosis.

Gelatinases (MMP-2 and -9) and their natural inhibitors as prognostic indicators in solid cancers

Neoplastic growth and dissemination involve increased proteolytic activity that is able to escape the regulative elements. Matrix metalloproteinases (MMPs), particularly gelatinases A and B (MMP-2 and -9), play a role in tumor invasion and angiogenesis, and they participate in cancer progression in several neoplasias. The expression of tissue inhibitors of gelatinases, TIMPs-1 and -2, has also been shown to be associated with the clinical course in some cancers. The prognostic value of these markers, however, seems to vary a great deal in different neoplastic diseases. In this review, the impact of the gelatinases and their inhibitors on the clinical course in several solid cancers is evaluated based on the growing data from recent clinical studies. The clinical data most often explore the overexpression of mRNA or immunoreactive protein in tumor tissue, or measure the concentration of the circulating proteinase or its inhibitor in pretreatment or follow-up serum samples. The growing amount of recent clinical data suggests that the impact of gelatinases on treatment decisions should be tested in clinical trials.

Vascular endothelial growth factor and angiogenesis

Angiogenesis is a hallmark of wound healing, the menstrual cycle, cancer, and various ischemic and inflammatory diseases. A rich variety of pro- and antiangiogenic molecules have already been discovered. Vascular endothelial growth factor (VEGF) is an interesting inducer of angiogenesis and lymphangiogenesis, because it is a highly specific mitogen for endothelial cells. Signal transduction involves binding to tyrosine kinase receptors and results in endothelial cell proliferation, migration, and new vessel formation. In this article, the role of VEGF in physiological and pathological processes is reviewed. We also discuss how modulation of VEGF expression creates new therapeutic possibilities and describe recent developments in this field.

Expression patterns of angiogenic and lymphangiogenic factors in ductal breast carcinoma in situ

The objective of this study was to investigate expression of various growth factors associated with angiogenesis and lymphangiogenesis and of their receptors in ductal carcinomas in situ of the breast (DCIS). We studied protein expression of basic fibroblast growth factor (bFGF), vascular endothelial growth factor (VEGF)-A, endothelin (ET)-1, and VEGF-C, and their receptors bFGF-R1, Flt-1, KDR, ET_AR, ET_BR, and Flt-4 immunohistochemically in 200 DCIS (pure DCIS: n=96; DCIS adjacent to an invasive component: n=104) using self-constructed tissue microarrays. Basic fibroblast growth factor-R1, VEGF-C, Flt-4, and ET_AR were expressed in the tumour cells in the majority of cases, whereas bFGF and Flt-1 expression was rarely observed. VEGF-A, KDR, ET-1, and ET_BR were variably expressed. The findings of VEGF-C and its receptor Flt-4 as lymphangiogenic factors being expressed in tumour cells of nearly all DCIS lesions and the observed expression of various angiogenic growth factors in most DCIS suggest that in situ carcinomas are capable of inducing angiogenesis and lymphangiogenesis. Moreover, we found a higher angiogenic activity in pure DCIS as compared to DCIS with concomitant invasive carcinoma. This association of angiogenic factors with pure DCIS was considerably more pronounced in the subgroup of non-high-grade DCIS (n=103) as compared with high-grade DCIS (n=94). Determination of these angiogenic markers may therefore facilitate discrimination between biologically different subgroups of DCIS and could help to identify a particularly angiogenic subset with a potentially higher probability of recurrence or of progression to invasiveness. For these DCIS, targeting angiogenesis may represent a feasible therapeutic approach for prevention of progression of DCIS to invasion.

Transcriptional deregulation of VEGF, FGF2, TGF-beta1, 2, 3 and cognate receptors in breast tumorigenesis

Angiogenesis is an important event during the neoplastic process and is induced by the secretion of numerous growth factors from endothelial cells. Vascular endothelial growth factor (VEGF), basic fibroblastic growth factor (FGF2), and transforming growth factor-beta1, beta2, beta3 (TGF-beta1, 2, 3) and cognate receptors (TGF-betaRI, II, III) mRNA expression pattern was evaluated by RT-PCR in 25 breast cancer tissue samples and adjacent normal tissues, and correlated to clinicopathological features. Western blot analysis was performed to evaluate VEGF and TGF-beta1 protein levels. TGF-beta1 and TGF-beta3 mRNA levels were significantly different in breast cancer specimens of differing histology (ductal, lobular, other) (P=0.020 and P=0.043). No statistically significant difference was observed at the mRNA level of VEGF between normal and tumor tissues while elevated VEGF protein levels in tumors were associated with patients' menopausal status. A strong hormonal influence of ER and PR on TGF-beta mRNA expression was established. FGF2 transcript levels were substantially decreased in cancer compared to adjacent normal specimens (P=0.031). A disruption of mRNA co-expression patterns was observed in malignant breast tissues compared to controls. Western blot analysis revealed differences between VEGF and TGFbeta1 mRNA and their corresponding protein levels. A substantial negative correlation of TGF-beta1 protein and TGF-beta1 mRNA levels (P=0.016) was demonstrated by breast tissue-pair analysis. Summarizing, our findings suggest that transcript levels of the examined markers in breast cancer are associated with menopausal and hormonal status, while their co-expression pattern is altered in malignant tissues compared to controls. In addition the difference between VEGF and TGF-beta1 mRNA and protein levels observed, indicates that post-transcriptional mechanisms may regulate expression of these molecules in breast cancer.

VEGF, FGF2, TGFB1 and TGFBR1 mRNA expression levels correlate with the malignant transformation of the uterine cervix

Angiogenesis is a complex procedure induced by the secretion of numerous growth factors from endothelial cells. Vascular endothelial growth factor (VEGF), basic fibroblastic growth factor (FGF2), transforming growth factor-beta1, 2, 3 (TGFB1, 2, 3), and transforming growth factor-beta receptors (TGFBR1, 2, 3) mRNA expression pattern was evaluated in tissue samples with cervical intraepithelial neoplasia (CIN) and cervical cancer, compared to that of normal cervical tissues, and correlated to the clinical stage of the disease. Transcript levels of the above genes were assessed by RT-PCR analysis in a total of 44 cervical specimens. VEGF, TGFB1, TGFBR1, and FGF2 transcript levels were significantly different in the normal, CIN and cancer specimen groups (P=0.015, 0.001, 0.008, and 0.029, respectively). Higher TGFBR1 mRNA levels were observed in parallel with increased severity of the lesion, whereas FGF2 exhibited lower transcript levels. A highly significant increase of VEGF mRNA expression was found upon cervical neoplastic transformation (P<0.0001). High-grade squamous intraepithelial lesions exhibited higher VEGF mRNA levels than low-grade lesions (P=0.039). TGFBR1 and TGFBR3 receptors demonstrated significant co-expressions with TGFB2 (P<0.0001), and TGFB1 (P=0.005 and 0.002, respectively) in normal cervical specimens. However, a disruption of co-expression patterns was observed in the groups of CIN and cancer cases, compared to normal tissues. Our findings show that VEGF, FGF2, TGFB1 and TGFBR1 mRNA expression levels correlate with the malignant transformation of the uterine cervix. The involvement of the examined markers in cervical carcinogenesis is furthermore supported by the observed disruption of their mRNA co-expression patterns.

Angiogenesis in male breast cancer

Background

Male breast cancer is a rare but aggressive and devastating disease. This disease presents at a later stage and in a more advanced fashion than its female counterpart. The immunophenotype also appears to be distinct when compared to female breast cancer. Angiogenesis plays a permissive role in the development of a solid tumor and provides an avenue for nutrient exchange and waste removal. Recent scrutiny of angiogenesis in female breast cancer has shown it to be of significant prognostic value. It was hypothesized that this holds true in invasive ductal carcinoma of the male breast. In the context of male breast cancer, we investigated the relationship of survival and other clinico-pathological variables to the microvascular density of the tumor tissue.

Methods

Seventy-five cases of primary male breast cancer were identified using the records of the Saskatchewan Cancer Agency over a period of 26 years. Forty-seven cases of invasive ductal carcinoma of the male breast had formalin-fixed paraffin-embedded tissue blocks that were suitable for this study. All cases were reviewed. Immunohistochemical staining was performed for the angiogenic markers (cluster designations 31 (CD31), 34 (CD34) and 105 (CD105), von Willebrand factor (VWF), and vascular endothelial growth factor (VEGF)). Microvascular density (MVD) was determined using average, centre, and highest microvessel counts (AMC, CMC, and HMC, respectively). Statistical analyses compared differences in the distribution of survival times and times to relapse between levels of MVD, tumor size, node status and age at diagnosis. In addition, MVD values were compared within each marker, between each marker, and were also compared to clinico-pathological data.

Results

Advanced age and tumor size were related to shorter survival times. There were no statistically significant differences in distributions of survival times and times to relapse between levels of MVD variables. There was no significant difference in MVD between levels of the different clinico-pathological variables. MVD was strongly and significantly correlated between AMC, CMC and HMC for CD31, CD34, and CD105 (p < 0.01) and remained moderate to weak for VWF and VEGF.

Conclusion

Microvascular density does not appear to be an independent prognostic factor in male breast cancer. However, the likelihood of death for men with breast cancer is increased in the presence of increased age at diagnosis and advanced tumor size. This is perhaps linked to inherent tumor vasculature, which is strongly related throughout a tumor section.

Clinicopathological and prognostic implications of endoglin (CD105) expression in hepatocellular carcinoma and its adjacent non-tumorous liver

AIM: The expression pattern of endoglin (CD105) in hepatocellular carcinoma (HCC) has not been reported so far. We hypothesized that CD105 could differentially highlight a subset of microvessels in HCC, and intratumoral microvessel density (IMVD) by CD105 immunostaining (IMVD-CD105) could provide better prognostic information than IMVD by CD34 immunostaining (IMVD-CD34).

METHODS: Paraffin blocks of tumor and adjacent non-tumorous liver tissues from 86 patients who underwent curative resection of HCC were used for this study. Serial sections were stained for CD105 and CD34, respectively, to highlight the microvessels. IMVD was counted according to a standard protocol.

RESULTS: In the HCC tissues, CD105 was either negatively or positively stained only in a subset of microvessels. In contrast, CD34 showed positive and more extensive microvessel staining in all cases examined. However, in the adjacent non-tumorous liver sections, CD105 showed a diffuse pattern of microvessel staining in 20 of 86 cases, while CD34 showed negative or only focal staining of the sinusoids around portal area. Correlation with clinicopathological data demonstrated that lower scores of IMVD-CD105 were found in larger sized tumors [mean 41.4/0.74 mm² (>5 cm tumor) vs 65.9/0.74 mm² (≤5 cm tumor), P = 0.043] and more aggressive tumors, as indicated by venous infiltration [36.8/0.74 mm² (present) vs 64.2/0.74 mm² (absent), P = 0.020], microsatellite nodules [35.1/0.74 mm² (present) vs 65.9/0.74 mm² (absent), P = 0.012], and advanced TNM tumor stage [38.8/0.74 mm² (stage 3 or 4) vs 68.3/0.74 mm² (stage 1 or 2), P = 0.014]. No prognostic significance was observed when median values were used as cut-off points using either IMVD-CD105 or IMVD-CD34. However, the presence of the diffuse pattern of CD105 expression in the adjacent non-tumorous liver tissues predicted a poorer disease-free survival (median 8.6 vs 21.5 mo, P = 0.026).

CONCLUSION: Our data demonstrate that a lower IMVD-CD105 is associated with larger and more aggressive tumors. In this study, IMVD-CD105 did not provide significant prognostic information. However, active angiogenesis as highlighted by diffuse CD105 staining of the microvessels in the adjacent non-tumorous liver tissues is predictive of early recurrence.

Endothelin-1-, endothelin-A-, and endothelin-B-receptor expression is correlated with vascular endothelial growth factor expression and angiogenesis in breast cancer

PURPOSE

Endothelin-1 (ET-1) and its receptors (ET(A)R and ET(B)R), referred to as the endothelin (ET) axis, are overexpressed in breast carcinomas, and influence tumorigenesis and tumor progression by various mechanisms, including angiogenesis. The objective of the study was to clarify if expression of the ET axis participates in angiogenesis of breast carcinoma

EXPERIMENTAL DESIGN

We analyzed expression of ET-1, ET(A)R, ET(B)R, and vascular endothelial growth factor (VEGF) immunohistochemically in 600 tissue array specimens from 200 paraffin-embedded breast carcinomas performing tissue microarray technology. Microvessel density (MVD) was determined by counting microvessels (identified by factor VIII) in each core specimen.

RESULTS

Moderate or strong immunostaining was observed for ET-1 in 25.4%, for ET(A)R in 43.7%, and for ET(B)R in 22.2% of breast carcinomas. Of all cases, 44.7% showed significant expression of VEGF. MVD varied between different tumor specimens (range, 0-80; median, 17). We observed a statistically significant correlation between MVD and ET expression status with higher MVD in ET-positive tumors. Moreover, expression of VEGF was found more frequently in tumors with overexpression of the ET axis (each P < 0.001). Staining of VEGF was correlated positively with MVD CONCLUSIONS: These results indicate that increased ET-1, ET(A)R, and ET(B)R expression is associated with increased VEGF expression and higher vascularity of breast carcinomas and, thus, could be involved in the regulation of angiogenesis in breast cancer. Our findings provide evidence that the expression pattern of the ET-axis and in particular of ET(A)R may have clinical relevance in future antiangiogenic targeted therapies for breast cancer.