Angiogenesis of breast cancer

MEMS Ultrasound Transducers for Endoscopic Photoacoustic Imaging Applications

Photoacoustic imaging (PAI) is drawing extensive attention and gaining rapid development as an emerging biomedical imaging technology because of its high spatial resolution, large imaging depth, and rich optical contrast. PAI has great potential applications in endoscopy, but the progress of endoscopic PAI was hindered by the challenges of manufacturing and assembling miniature imaging components. Over the last decade, microelectromechanical systems (MEMS) technology has greatly facilitated the development of photoacoustic endoscopes and extended the realm of applicability of the PAI. As the key component of photoacoustic endoscopes, micromachined ultrasound transducers (MUTs), including piezoelectric MUTs (pMUTs) and capacitive MUTs (cMUTs), have been developed and explored for endoscopic PAI applications. In this article, the recent progress of pMUTs (thickness extension mode and flexural vibration mode) and cMUTs are reviewed and discussed with their applications in endoscopic PAI. Current PAI endoscopes based on pMUTs and cMUTs are also introduced and compared. Finally, the remaining challenges and future directions of MEMS ultrasound transducers for endoscopic PAI applications are given.

In vivo longitudinal and multimodal imaging of hypoxia-inducible factor 1α and angiogenesis in breast cancer

Background

Angiogenesis and hypoxia-inducible factor 1α (HIF-1α) play major roles in solid tumors. This study aimed to establish a longitudinal and multimodal imaging model for in vivo evaluation of HIF1α and angiogenesis in breast cancer.

Methods

By transfection of a 5 hypoxia-responsive element (HRE)/green fluorescent protein (GFP) plasmid, the cell line Ca761-hre-gfp was established, which emitted green fluorescence triggered by HIF-1α under hypoxia. The cells were subjected to CoCl₂-simulated hypoxia to confirm the imaging strategy. We grew Ca761-hre-gfp cells in the left rear flanks of twelve 615 mice. Experiments were conducted on days 4, 9, 15, and 19. For in vivo analysis, Ca761-hre-gfp subcutaneous allografted tumors were imaged in vivo using contrast-enhanced ultrasound (CEUS) and fluorescence imaging (FLI) during tumor development. The tumor size, CEUS peak intensity, and FLI photons were measured to evaluate tumor growth, angiogenesis, and HIF-1α activity, respectively. After each experiment, three mice were randomly sacrificed and tumor specimens were collected to examine HIF-1α activity and the microvessel density (MVD).

Results

In vitro, both green fluorescence and HIF-1α expression were detected in Ca761-hre-gfp cells treated with CoCl₂, indicating the suitability of the cells to detect HIF-1α activity. In vivo, HIF-1α activity first increased and then decreased, which was significantly correlated with angiogenic changes (r = 0.803, P = 0.005). These changes were confirmed by immunohistochemical staining of HIF-1α and MVD.

Conclusions

The findings validated the Ca761-hre-gfp murine allograft model for reliable evaluation of HIF-1α activity and angiogenesis longitudinally using both molecular and pre-clinical non-invasive imaging modalities. The cell line may be useful for studies of anti-HIF pathway therapies.

Peptides, proteins and nanotechnology: a promising synergy for breast cancer targeting and treatment

INTRODUCTION

The use of nanoparticles for breast cancer targeting and treatment has become a reality. They are safe and possess interesting peculiarities such as the unspecific accumulation into the tumor site and the possibility to activate controlled drug release as compared to free drugs. However, there are still many areas of improvement which can certainly be addressed with the use of peptide-based elements.

AREAS COVERED

The article reviews different preclinical strategies employing peptides and proteins in combination with nanoparticles for breast cancer targeting and treatment as well as peptide and protein-targeted encapsulated drugs, and it lists the current clinical status of therapies using peptides and proteins for breast cancer.

EXPERT OPINION

The conjugation of protein and peptides can improve tumor homing of nanoparticles, increase cellular penetration and attack specific drivers and vulnerabilities of the breast cancer cell to promote tumor cytotoxicity while reducing secondary effects in healthy tissues. Examples are the use of antibodies, arginylglycylaspartic acid (RGD) peptides, membrane disruptive peptides, interference peptides, and peptide vaccines. Although their implementation in the clinic has been relatively slow up to now, we anticipate great progress in the field which will translate into more efficacious and selective nanotherapies for breast cancer.

The Multifaceted Nature of Tumor Microenvironment in Breast Carcinomas

Heterogeneity in breast carcinomas can be appreciated at various levels, from morphology to molecular alterations, and there are well-known genotypic-phenotypic correlations. Clinical decision-making is strictly focused on the evaluation of tumor cells and is based on the assessment of hormone receptors and of the HER2 status, by means of a combination of immunohistochemical and in situ hybridization techniques. The tumor microenvironment (TME) also shows a multifaceted nature stemming from the different actors populating the intratumoral and the peritumoral stroma of breast carcinomas. Of note, we have now evidence that tumor-infiltrating lymphocytes (TILs) are clinically meaningful as their quantification in the intratumoral stroma strongly correlates with good prognosis, in particular in triple-negative and HER2-positive breast cancer patients. Nevertheless, TILs are just one of the many actors orchestrating the complexity of the TME, which is populated by immune and non-immune cells (cancer-associated fibroblasts, cancer-associated adipocytes), as well as non-cellular components such as chemical inflammation mediators. In this review article we will overview the main features of the distinct cell compartments by discussing (i) the potential impact the TME may have on the prognostic stratification of breast cancers and (ii) the possible predictive value of some markers in the context of immunotherapy in light of the recent results of phase III studies in advanced and early triple-negative breast cancer patients.

The additional utility of ultrafast MRI on conventional DCE-MRI in evaluating preoperative MRI of breast cancer patients

PURPOSE

To investigate whether the additional use of ultrafast MRI can improve the diagnostic performance of conventional dynamic contrast-enhanced MRI (DCE-MRI) in evaluating MRI-detected lesions in breast cancer patients.

METHODS

This retrospective study enrolled 101 consecutive breast cancer patients with 202 breast lesions (62 benign and 140 malignant) who underwent preoperative DCE-MRI with ultrafast imaging (9 image sets with 6.5-second temporal resolution). Two reviewers assessed the BI-RADS categories of breast lesions using conventional DCE-MRI and assessed the following parameters using the ultrafast MRI: initial enhancement phase, maximum relative enhancement, slope, and maximum slope (slope_max) on the kinetic curve. Interobserver agreement was analyzed between the two reviewers. The ultrafast MRI parameters were compared between benign and malignant tumors, and cut-off values were determined. For 97 additional MRI-detected lesions, the BI-RADS category was re-assessed using cut-off values, and the diagnostic performance was compared between the conventional DCE-MRI and the combined conventional and ultrafast DCE-MRI.

RESULTS

All ultrafast MRI parameters differed significantly between malignant and benign tumors (p < 0.001). Initial enhancement phase by reviewer and slope_max were the top two parameters showing significant differences between benign and malignant tumors with high reliability. With the use of cut-off values for initial enhancement phase (≤phase 2) and slope_max (>9.8%/sec), the specificity of conventional DCE-MRI was significantly increased (29.4% vs 64.7%, p < 0.001) without significant loss of sensitivity (100% vs 88.2%, p = 0.157) in evaluating masses.

CONCLUSIONS

The additional use of ultrafast MRI can improve the specificity of conventional DCE-MRI when evaluating MRI-detected masses in breast cancer patients.

A Prospective Study on the Value of Ultrasound Microflow Assessment to Distinguish Malignant from Benign Solid Breast Masses: Association between Ultrasound Parameters and Histologic Microvessel Densities

OBJECTIVE

To investigate the value of ultrasound (US) microflow assessment in distinguishing malignant from benign solid breast masses as well as the association between US parameters and histologic microvessel density (MVD).

MATERIALS AND METHODS

Ninety-eight breast masses (57 benign and 41 malignant) were examined using Superb Microvascular Imaging (SMI) and contrast-enhanced US (CEUS) before biopsy. Two radiologists evaluated the quantitative and qualitative vascular parameters on SMI (vascular index, morphology, distribution, and penetration) and CEUS (time-intensity curve analysis and enhancement characteristics). US parameters were compared between benign and malignant masses and the diagnostic performance was compared between SMI and CEUS. Subgroup analysis was performed according to lesion size. The effect of vascular parameters on downgrading Breast Imaging Reporting and Data System (BI-RADS) category 4A masses was evaluated. The association between histologic MVD and US parameters was analyzed.

RESULTS

Malignant masses were associated with a higher vascular index (15.1 ± 7.3 vs. 5.9 ± 5.6), complex vessel morphology (82.9% vs. 42.1%), central vascularity (95.1% vs. 59.6%), penetrating vessels (80.5% vs. 31.6%) on SMI (all, p < 0.001), as well as higher peak intensity (37.1 ± 25.7 vs. 17.0 ± 15.8, p < 0.001), slope (10.6 ± 11.2 vs. 3.9 ± 4.2, p = 0.001), area (1035.7 ± 726.9 vs. 458.2 ± 410.2, p < 0.001), hyperenhancement (95.1% vs. 70.2%, p = 0.005), centripetal enhancement (70.7% vs. 45.6%, p = 0.023), penetrating vessels (65.9% vs. 22.8%, p < 0.001), and perfusion defects (31.7% vs. 3.5%, p < 0.001) on CEUS (p ≤ 0.023). The areas under the receiver operating characteristic curve (AUCs) of SMI and CEUS were 0.853 and 0.841, respectively (p = 0.803). In 19 masses measuring < 10 mm, central vascularity on SMI was associated with malignancy (100% vs. 38.5%, p = 0.018). Considering all benign SMI parameters on the BI-RADS assessment, unnecessary biopsies could be avoided in 12 category 4A masses with improved AUCs (0.500 vs. 0.605, p < 0.001). US vascular parameters associated with malignancy showed higher MVD (p ≤ 0.016). MVD was higher in malignant masses than in benign masses, and malignant masses negative for estrogen receptor or positive for Ki67 had higher MVD (p < 0.05).

CONCLUSION

US microflow assessment using SMI and CEUS is valuable in distinguishing malignant from benign solid breast masses, and US vascular parameters are associated with histologic MVD.

Differential expression of angiogenesis-related miRNAs and VEGFA in cirrhosis and hepatocellular carcinoma

INTRODUCTION

Liver cirrhosis (LC) is a heterogeneous liver disease, the last stage of liver fibrosis, and the major risk factor for hepatocellular carcinoma (HCC). Our study aimed to evaluate the expression of microRNAs and the endothelial vascular growth factor (VEGFA) gene in LC and HCC.

MATERIAL AND METHODS

The sample group consisted of 46 tissue samples: 21 of LC, 15 of HCC, and 10 of non-tumoural and non-cirrhotic liver tissue (control group). MiRNAs were chosen based on a mirDIP prediction database as regulators of the VEGFA gene. Gene expression of VEGF and miRNAs was quantified by real-time quantitative polymerase chain reaction. VEGFA protein expression was evaluated by ELISA.

RESULTS

VEGFA gene expression was significantly overexpressed in LC compared to the control group (p < 0.0001). Hsa-miR-206 (p = 0.0313) and hsa-miR-637 (p = 0.0156) were down-expressed in LC. In HCC, hsa-miR-15b (p = 0.0010), hsa-miR-125b (p = 0.0010), hsa-miR-423-3p (p = 0.0010), hsa-miR-424 (p = 0.0313), hsa-miR-494 (p < 0.0001), hsa-miR-497 (p < 0.0001), hsa-miR-612 (p = 0.0078), hsa-miR-637 (p < 0.0001), and hsa-miR-1255b (p = 0.0156) presented down-expression.

CONCLUSIONS

Overexpression of VEGFA in LC suggests impairment of angiogenesis in this tissue. The differential expression of microRNAs in LC and HCC observed in our study can lead to the evaluation of possible biomarkers for these diseases.

cAMP regulated EPAC1 supports microvascular density, angiogenic and metastatic properties in a model of triple negative breast cancer

Breast cancer is a leading cause of cancer-related mortality in women. Triple-negative breast cancer (TNBC; HER2-, ER-/PR-) is an aggressive subtype prone to drug resistance and metastasis, which is characterized by high intratumor microvascular density (iMVD) resulting from angiogenesis. However, the mechanisms contributing to the aggressive phenotypes of TNBC remain elusive. We recently reported that down-regulation of exchange factor directly activated by cyclic AMP (cAMP), also known as EPAC1, leads to a reduction in metastatic properties including proliferation and cell migration in TNBC cell lines. Here, we report that EPAC1 supports TNBC-induced angiogenesis, tumor cell migration and invasiveness as well as pro-metastatic phenotypes in endothelial cells induced through the tumor secretome. Using an approach that integrates proteomics with bioinformatics and gene ontologies, we elucidate that EPAC1 supports a tumor-secreted network of angiogenic, cell adhesion and cell migratory pathways. Using confocal microscopy, we show that signaling molecules involved in focal adhesion, including Paxillin and MENA, are down-regulated in the absence of EPAC1, and electric cell substrate impedance sensing technique confirmed a role for EPAC1 on TNBC-induced endothelial cell permeability. Finally, to provide a translational bridge, we studied iMVD and therapy response using a primary human tumor explant assay, CANscriptTM, which suggests a link between therapy-modulated neovascularization and drug sensitivity. These data provide mechanistic insight into the role of EPAC1 in regulating the tumor microenvironment, iMVD and cancer cell-induced angiogenesis, a dynamic mechanism under drug pressure that may associate to treatment failure.

Apatinib combined with chemotherapy in patients with previously treated advanced breast cancer: An observational study

Locally advanced or metastatic disease accounts for the majority of breast cancer-associated cases of mortality. Treatment options for patients with locally advanced or metastatic disease are limited. The current study aimed to explore the efficacy and safety of apatinib combined with chemotherapy in patients with previously treated advanced breast cancer in real-world clinical practice. A total of 85 patients with advanced breast cancer, who had previously been exposed to anthracyclines or taxanes, received combined treatment. Tumor response was evaluated by a computed tomography scan based on the Response Evaluation Criteria in Solid Tumors. Adverse events were graded based on the Common Terminology Criteria for Adverse Events. The Kaplan-Meier method and a log-rank test were used to analyze the univariate discrimination of progression-free survival (PFS) and overall survival (OS) by demographic data, baseline clinical information and toxicities. The combined effects of these variables were analyzed by a Cox proportional hazards regression model. At a median follow-up time of 9.7 months, 73 patients exhibited disease progression and 48 had succumbed to the disease. During the follow-up, 19 patients demonstrated a partial response (PR) and 53 patients achieved stable disease (SD), with an objective response rate of 23.2%. Additionally, 39 patients demonstrated a PR or SD for ≥24 weeks, with a clinical benefit rate of 47.6%. The median PFS was 4.4 months [95% confidence interval (CI)=2.8-6.0] and the median OS was 11.3 months (95% CI=8.9-13.8). No treatment-associated mortalities occurred. The most common adverse events of all grades included myelosuppression (49.4%), gastrointestinal reaction (45.9%) and fatigue (43.5%). Proteinuria was an independent predictive factor for PFS and OS. Apatinib combined with chemotherapy appeared to be efficacious for pretreated advanced breast cancer, with acceptable toxicity for real-world clinical practice.

Kinetic Features of Invasive Breast Cancers on Computer-Aided Diagnosis Using 3T MRI Data: Correlation with Clinical and Pathologic Prognostic Factors

OBJECTIVE

To investigate the correlation of kinetic features of breast cancers on computer-aided diagnosis (CAD) of preoperative 3T magnetic resonance imaging (MRI) data and clinical-pathologic factors in breast cancer patients.

MATERIALS AND METHODS

Between July 2016 and March 2017, 85 patients (mean age, 54 years; age range, 35-81 years) with invasive breast cancers (mean, 1.8 cm; range, 0.8-4.8 cm) who had undergone MRI and surgery were retrospectively enrolled. All magnetic resonance images were processed using CAD, and kinetic features of tumors were acquired. The relationships between kinetic features and clinical-pathologic factors were assessed using Spearman correlation test and binary logistic regression analysis.

RESULTS

Peak enhancement and angio-volume were significantly correlated with histologic grade, Ki-67 index, and tumor size: r = 0.355 (p = 0.001), r = 0.330 (p = 0.002), and r = 0.231 (p = 0.033) for peak enhancement, r = 0.410 (p = 0.005), r = 0.341 (p < 0.001), and r = 0.505 (p < 0.001) for angio-volume. Delayed-plateau component was correlated with Ki-67 (r = 0.255 [p = 0.019]). In regression analysis, higher peak enhancement was associated with higher histologic grade (odds ratio [OR] = 1.004; 95% confidence interval [CI]: 1.001-1.008; p = 0.024), and higher delayed-plateau component and angio-volume were associated with higher Ki-67 (Or = 1.051; 95% CI: 1.011-1.094; p = 0.013 for delayed-plateau component, OR = 1.178; 95% CI: 1.023-1.356; p = 0.023 for angio-volume).

CONCLUSION

Of the CAD-assessed kinetic features, higher peak enhancement may correlate with higher histologic grade, and higher delayed-plateau component and angio-volume correlate with higher Ki-67 index. These results support the clinical application of kinetic features in prognosis assessment.

Dynamic Function of DPMS Is Essential for Angiogenesis and Cancer Progression

Dolichol phosphate mannose synthase (DPMS) is an inverting GT-A-folded enzyme and classified as GT2 by CAZy. DPMS sequence carries a metal-binding DXD motif, a PKA motif, and a variable number of hydrophobic domains. Human and bovine DPMS possess a single transmembrane domain, whereas that from S. cerevisiae and A. thaliana carry multiple transmembrane domains and are superimposable. The catalytic activity of DPMS is documented in all spheres of life, and the 32kDa protein is uniquely regulated by protein phosphorylation. Intracellular activation of DPMS by cAMP signaling is truly due to the activation of the enzyme and not due to increased Dol-P level. The sequence of DPMS in some species also carries a protein N-glycosylation motif (Asn-X-Ser/Thr). Apart from participating in N-glycan biosynthesis, DPMS is essential for the synthesis of GPI anchor as well as for O- and C-mannosylation of proteins. Because of the dynamic nature, DPMS actively participates in cellular proliferation enhancing angiogenesis and breast tumor progression. In fact, overexpression of DPMS in capillary endothelial cells supports increased N-glycosylation, cellular proliferation, and enhanced chemotactic activity. These are expected to be completely absent in congenital disorders of glycosylation (CDGs) due to the silence of DPMS catalytic activity. DPMS has also been found to be involved in the cross talk with N-acetylglucosaminyl 1-phosphate transferase (GPT). Inhibition of GPT with tunicamycin downregulates the DPMS catalytic activity quantitatively. The result is impairment of surface N-glycan expression, inhibition of angiogenesis, proliferation of human breast cancer cells, and induction of apoptosis. Interestingly, nano-formulated tunicamycin is three times more potent in inhibiting the cell cycle progression than the native tunicamycin and is supported by downregulation of the ratio of phospho-p53 to total-p53 as well as phospho-Rb to total Rb. DPMS expression is also reduced significantly. However, nano-formulated tunicamycin does not induce apoptosis. We, therefore, conclude that DPMS could become a novel target for developing glycotherapy treating breast tumor in the clinic.

Long term use of bevacizumab in the treatment of triple negative breast cancer with giant tumor in chest wall: A case report

RATIONALE

Triple-negative breast cancer (TNBC) is associated with unfavorable prognosis due to lack of targeted agents. Bevacizumab, an anti-angiogenic monoclonal antibody against vascular endothelial growth factor A, has shown clinical effects in patients with TNBC.

PATIENT CONCERNS

We reported a 49-year-old woman presenting with a giant breast tumor.

DIAGNOSES

Stage IV TNBC with chest wall metastasis.

INTERVENTIONS

The patient underwent long-term use of bevacizumab combined with chemotherapy.

OUTCOMES

The patient was on follow-up for 46 months, a remarkable improvement of the chest wall cutaneous lesion was observed.

LESSONS

Bevacizumab may provide benefits for TNBC patients with chest wall metastasis.

Using a Classifier Fusion Strategy to Identify Anti-angiogenic Peptides

Anti-angiogenic peptides perform distinct physiological functions and potential therapies for angiogenesis-related diseases. Accurate identification of anti-angiogenic peptides may provide significant clues to understand the essential angiogenic homeostasis within tissues and develop antineoplastic therapies. In this study, an ensemble predictor is proposed for anti-angiogenic peptide prediction by fusing an individual classifier with the best sensitivity and another individual one with the best specificity. We investigate predictive capabilities of various feature spaces with respect to the corresponding optimal individual classifiers and ensemble classifiers. The accuracy and Matthew’s Correlation Coefficient (MCC) of the ensemble classifier trained by Bi-profile Bayes (BpB) features are 0.822 and 0.649, respectively, which represents the highest prediction results among the investigated prediction models. Discriminative features are obtained from BpB using the Relief algorithm followed by the Incremental Feature Selection (IFS) method. The sensitivity, specificity, accuracy, and MCC of the ensemble classifier trained by the discriminative features reach up to 0.776, 0.888, 0.832, and 0.668, respectively. Experimental results indicate that the proposed method is far superior to the previous study for anti-angiogenic peptide prediction.

A small molecule targeting myoferlin exerts promising anti-tumor effects on breast cancer

Breast cancer is one of the most lethal cancers in women when it reaches the metastatic stage. Here, we screen a library of small molecules for inhibitors of breast cancer cell invasion, and use structure/activity relationship studies to develop a series of small molecules with improved activity. We find WJ460 as one of the lead compounds exerting anti-metastatic activity in the nanomolar range in breast cancer cells. Proteomic and biochemical studies identify myoferlin (MYOF) as the direct target of WJ460. In parallel, loss of MYOF or pharmacological inhibition of MYOF by WJ460 reduces breast cancer extravasation into the lung parenchyma in an experimental metastasis mouse model, which reveals an essential role of MYOF in breast cancer progression. Our findings suggest that MYOF can be explored as a molecular target in breast cancer metastasis and that targeting MYOF by WJ460 may be a promising therapeutic strategy in MYOF-driven cancers.

Improved therapeutics are needed for treating breast cancer. Here they show the druggability of myoferlin with a small molecule inhibitor in breast cancer and demonstrate its anti-breast cancer effects in vitro and in vivo.

Background Removal and Vessel Filtering of Noncontrast Ultrasound Images of Microvasculature

OBJECTIVE

Recent advances in ultrasound Doppler imaging have made it possible to visualize small vessels with diameters near the imaging resolution limits using spatiotemporal singular value thresholding of long ensembles of ultrasound data. However, vessel images derived based on this method present severe intensity variations and additional background noise that limits visibility and subsequent processing such as centerline extraction and morphological analysis. The goal of this paper is to devise a method to enhance vessel-background separation directly on the power Doppler images by exploiting blood echo-noise independence.

METHOD

We present a two-step algorithm to mitigate these adverse effects when using singular value thresholding for obtaining gross vasculature images. Our method comprises a morphological-based filtering for removing global and local background signals and a multiscale Hessian-based vessel enhancement filtering to further improve the vascular structures. We applied our method for in vivo imaging of the microvasculature of kidney in one healthy subject, liver in five healthy subjects, thyroid nodules in five patients, and breast tumors in five patients.

RESULTS

Singular value thresholding, top-hat filtering, and Hessian-based vessel enhancement filtering each provided an average peak-to-side level gain of 1.11, 18.55, and 2.26 dB, respectively, resulting in an overall gain of 21.92 dB when compared to the conventional power Doppler imaging using infinite impulse response filtering.

CONCLUSION

Singular value thresholding combined with morphological and Hessian-based vessel enhancement filtering provides a powerful tool for visualization of the deep-seated small vessels using long ultrasound echo ensembles without requiring any type of contrast enhancing agents.

SIGNIFICANCE

This method provides a fast and cost-effective modality for in vivo assessment of the microvasculature suitable for both clinical and preclinical applications.

Single-breath-hold photoacoustic computed tomography of the breast

We have developed a single-breath-hold photoacoustic computed tomography (SBH-PACT) system to reveal detailed angiographic structures in human breasts. SBH-PACT features a deep penetration depth (4 cm in vivo) with high spatial and temporal resolutions (255 µm in-plane resolution and a 10 Hz 2D frame rate). By scanning the entire breast within a single breath hold (~15 s), a volumetric image can be acquired and subsequently reconstructed utilizing 3D back-projection with negligible breathing-induced motion artifacts. SBH-PACT clearly reveals tumors by observing higher blood vessel densities associated with tumors at high spatial resolution, showing early promise for high sensitivity in radiographically dense breasts. In addition to blood vessel imaging, the high imaging speed enables dynamic studies, such as photoacoustic elastography, which identifies tumors by showing less compliance. We imaged breast cancer patients with breast sizes ranging from B cup to DD cup, and skin pigmentations ranging from light to dark. SBH-PACT identified all the tumors without resorting to ionizing radiation or exogenous contrast, posing no health risks.

Angiogenesis - a crucial step in breast cancer growth, progression and dissemination by Raman imaging

Combined micro-Raman imaging and AFM imaging are efficient methods for analyzing human tissue due to their high spatial and spectral resolution as well as sensitivity to subtle chemical, structural and topographical changes. The aim of this study was to determine biochemical composition and mechanical topography around blood vessels in the tumor mass of human breast tissue. Significant alterations of the chemical composition and structural architecture around the blood vessel were found compared to the normal breast tissue. A pronounced increase of collagen-fibroblast-glycocalyx network, as well as enhanced lactic acid, and glycogen activity in patients affected by breast cancer were reported.

Impact of semaphorin expression on prognostic characteristics in breast cancer

Breast cancer is one of the major causes of cancer-related deaths among women worldwide. Aberrant regulation of various growth factors, cytokines, and other proteins and their receptors in cancer cells drives the activation of various oncogenic signaling pathways that lead to cancer progression. Semaphorins are a class of proteins which are differentially expressed in various types of cancer including breast cancer. Earlier, these proteins were known to have a major function in the nerve cell adhesion, migration, and development of the central nervous system. However, their role in the regulation of several aspects of tumor progression has eventually emerged. There are over 30 genes encoding the semaphorins, which are divided into eight subclasses. It has been reported that some members of semaphorin classes are antiangiogenic and antimetastatic in nature, whereas others act as proangiogenic and prometastatic genes. Because of their differential expression and role in angiogenesis and metastasis, semaphorins emerged as one of the important prognostic factors for appraising breast cancer progression.

Potential Impact of Vascular Endothelial Growth Factor Gene Variation (-2578C>A) on Breast Cancer Susceptibility in Saudi Arabia: a Case-Control Study

Aim:

VEGF gene polymorphisms can induce either increase or inhibition of VEGF secretion, with altered promoter activity. The VEGF rs699947 SNP is located in the promoter region and is associated with susceptibility to breast carcinoma development. Here, we investigated the association of the -2578C>A polymorphism in the VEGF gene with breast cancer risk in Saudi women.

Methodology:

Genotyping of the VEGF-gene variation (-2578A>C) was performed using the amplification refractory mutation system PCR. We investigated the association of VEGF gene variants with different clinicopathological features of breast cancer patients.

Results:

A significant difference was observed in genotype distribution among the breast cancer cases and sex matched healthy controls (p=0.03). The frequencies of the three genotypes CC, CA, AA found in the patient samples were 37%, 45% and 18% and in the healthy controls were 54%,37%, and 09% respectively. An increased risk of developing breast cancer in Saudi women was associated with the VEGF −2578 AA genotype (OR = 2.91, 95 % CI, 1.18-7.20; p = 0.01; RR 1.78 (1.01-3.11 p=0.01), the VEGF −2578 A allele (OR = 1.79, 95 % CI, 1.17-2.73; p = 0.004: RR 1.35 1.07-1.71) and the VEGFR-(CA+ AA) (OR 1.99 1.13-3.51; RR 1.401.0-1.85). Thus the A allele increased the risk of BC when compared with C allele. When we stratified groups of patients according to the status of tumor markers, stage, age and metastasis, statistically significant associations with −2578 C/A SNP were revealed.

Conclusion:

Our data showed a significant association of the VEGF -2578C>A polymorphism with BC susceptibility in Saudi women. The VEGF -2578AA homozygote significantly increases the risk and can be useful as a predisposing genetic marker. Further studies with larger sample sizes are necessary to confirm our findings.

MDA-MB-231 and 8701BC breast cancer lines promote the migration and invasiveness of ECV304 cells on 2D and 3D type-I collagen matrix

Tumor angiogenesis is a multiphasic process, having the extracellular matrix remodeling as critical step. Different classes of proteolytic enzymes in matrix digestion/remodeling are involved. The role of lytic enzymes and their activation mode have not been completely elucidated. Herein, the crosstalk between endothelia and tumor cells, by realization of bi- and three-dimensional endothelial and breast cancer cells co-cultures, were studied in vitro. Particularly, the effects of two tumor conditioned media (TCM) were assessed about endothelial proliferation, migration, and invasiveness. An increase in expression of pro-MMP9 was detected when endothelial cells were cultured in the presence of both TCM; such as an up-regulation of MMP1 and MMP14 and a down-regulation of MMP7. Moreover the increased MMP2 gene expression from one of them and the stimulation MMP3 synthesis from the other one were observed; an increases of β3-integrin, VEGFA, and DPP4 molecules were detected when endothelia cells are cultured with both TCM. The selection/characterization of elements present in conditioned media from breast cancer cells differently affect endothelial cells, make them potential effectors useful in breast cancer treatment.

Interleukin-1 receptor antagonist inhibits angiogenesis in gastric cancer

BACKGROUND

Interleukin-1 alpha (IL-1α) plays an important role in tumorigenesis and angiogenesis of gastric cancer. The interleukin-1 receptor antagonist (IL-1RA) inhibits IL-1 selectively and specifically through IL-1R type I (IL-1RI). However, the underlying mechanism by which IL-1RA modulates the interactions of tumor cells and their micro-environment is poorly understood. We have evaluated the role of IL-1RA in the metastatic process as well as the mutual or reciprocal actions between gastric cancer cells and stromal cells.

MATERIALS AND METHODS

The expressions of IL-1α, vascular endothelial growth factor (VEGF), and IL-1RI mRNA were determined by reverse transcriptase-PCR. The regulatory effect of IL-1RA on the secretion of VEGF in human gastric cancer cells and human umbilical vein endothelial cells (HUVECs) was detected by enzyme-linked immunosorbent assay. The effect of IL-1RA on metastatic potential was evaluated using proliferation, invasion, and angiogenesis assays, respectively, including in vitro co-culture system models consisting of tumor cells and stromal cells that were used to detect invasion and angiogenesis.

RESULTS

Interleukin-1α mRNA was detected in the higher liver metastatic gastric cell line MKN45. IL-1α protein was expressed in MKN45 cells and in HUVECs. VEGF mRNA and protein were detected in the three gastric cancer cell lines (MKN4, NUGC-4, and AGS). Levels of VEGF secreted by gastric cancer cells and HUVECs appeared to be reduced through the action of IL-1RA via IL-1RI in a dose-dependent manner (P < 0.01). IL-1RA significantly inhibited the proliferation and migration of HUVECs (P < 0.01) and tube formation by HUVECs (P < 0.01), both in a dose-dependent manner. Compared with HUVECs grown without cancer cells (control) or with NUGC-4 cells, tube formation by HUVECs was significantly enhanced by co-culture with MKN45 cells (P < 0.01). The enhanced tube formation in the presence of MKN45 cells was inhibited by the addition of IL-1RA (P < 0.01).

CONCLUSIONS

The IL-1RA downregulated the metastatic potential of gastric cancer through blockage of the IL-1α/VEGF signaling pathways. IL-1RA has the potential to play a role in the treatment of gastric cancer.

Radiation-enhanced therapeutic targeting of galectin-1 enriched malignant stroma in triple negative breast cancer

Currently there are no FDA approved targeted therapies for Triple Negative Breast Cancer (TNBC). Ongoing clinical trials for TNBC have focused primarily on targeting the epithelial cancer cells. However, targeted delivery of cytotoxic payloads to the non-transformed tumor associated-endothelium can prove to be an alternate approach that is currently unexplored. The present study is supported by recent findings on elevated expression of stromal galectin-1 in clinical samples of TNBC and our ongoing findings on stromal targeting of radiation induced galectin-1 by the anginex-conjugated arsenic-cisplatin loaded liposomes using a novel murine tumor model. We demonstrate inhibition of tumor growth and metastasis in response to the multimodal nanotherapeutic strategy using a TNBC model with orthotopic tumors originating from 3D tumor tissue analogs (TTA) comprised of tumor cells, endothelial cells and fibroblasts. The ‘rigorous’ combined treatment regimen of radiation and targeted liposomes is also shown to be well tolerated. More importantly, the results presented provide a means to exploit clinically relevant radiation dose for concurrent receptor mediated enhanced delivery of chemotherapy while limiting overall toxicity. The proposed study is significant as it falls in line with developing combinatorial therapeutic approaches for stroma-directed tumor targeting using tumor models that have an appropriate representation of the TNBC microenvironment.

Artemin promotes oncogenicity, metastasis and drug resistance in cancer cells

Artemin (ARTN) is a member of glial cell line-derived neurotrophic factor (GDNF) family of ligands, and its signaling is mediated via a multi-component receptor complex including the glycosylphosphatidylinositol-anchored GDNF family receptors a (GFRa1, GFRa3) and RET receptor tyrosine kinase. The major mechanism of ARTN action is via binding to a non-signaling co-receptor. The major function of ARTN is to drive the molecule to induce migration and axonal projection from sympathetic neurons. It also promotes the survival, proliferation and neurite outgrowth of sympathetic neurons in vitro. ARTN triggers oncogenicity and metastasis by the activation of the AKT signaling pathway. Recent studies have reported that the expression of ARTN in hepatocellular carcinoma is associated with increased tumor size, quick relapse and shorter survival. Furthermore, ARTN promotes drug resistance such as antiestrogens, doxorubicin, fulvestrant, paclitaxel, tamoxifen and trastuzumab. Moreover, ARTN also stimulates the radio-therapeutic resistance. This review highlights the proposed roles of ARTN in cancer cells and discusses recent results supporting its emerging role as an oncogenic, metastatic and drug-resisting agent with a special focus on how these new insights may facilitate rational development of ARTN for targeted therapies in the future.

Contribution of Adipose Tissue to Development of Cancer

Solid tumor growth and metastasis require the interaction of tumor cells with the surrounding tissue, leading to a view of tumors as tissue-level phenomena rather than exclusively cell-intrinsic anomalies. Due to the ubiquitous nature of adipose tissue, many types of solid tumors grow in proximate or direct contact with adipocytes and adipose-associated stromal and vascular components, such as fibroblasts and other connective tissue cells, stem and progenitor cells, endothelial cells, innate and adaptive immune cells, and extracellular signaling and matrix components. Excess adiposity in obesity both increases risk of cancer development and negatively influences prognosis in several cancer types, in part due to interaction with adipose tissue cell populations. Herein, we review the cellular and noncellular constituents of the adipose "organ," and discuss the mechanisms by which these varied microenvironmental components contribute to tumor development, with special emphasis on obesity. Due to the prevalence of breast and prostate cancers in the United States, their close anatomical proximity to adipose tissue depots, and their complex epidemiologic associations with obesity, we particularly highlight research addressing the contribution of adipose tissue to the initiation and progression of these cancer types. Obesity dramatically modifies the adipose tissue microenvironment in numerous ways, including induction of fibrosis and angiogenesis, increased stem cell abundance, and expansion of proinflammatory immune cells. As many of these changes also resemble shifts observed within the tumor microenvironment, proximity to adipose tissue may present a hospitable environment to developing tumors, providing a critical link between adiposity and tumorigenesis. © 2018 American Physiological Society. Compr Physiol 8:237-282, 2018.

RESILIENCE: Phase III Randomized, Double-Blind Trial Comparing Sorafenib With Capecitabine Versus Placebo With Capecitabine in Locally Advanced or Metastatic HER2-Negative Breast Cancer

INTRODUCTION

Sorafenib is a multikinase inhibitor with antiangiogenic/antiproliferative activity. In this randomized, double-blind, placebo-controlled phase III trial, we assessed first- or second-line capecitabine with sorafenib or placebo in patients with locally advanced/metastatic HER2-negative breast cancer resistant to a taxane and anthracycline and with known estrogen/progesterone receptor status.

PATIENTS AND METHODS

A total of 537 patients were randomized to capecitabine 1000 mg/m2 orally twice per day for days 1 to 14 every 21 days with oral sorafenib 600 mg/d or placebo. The primary end point was progression-free survival (PFS). Patients were stratified according to hormone receptor status, previous chemotherapies for metastatic breast cancer, and geographic region.

RESULTS

Treatment with sorafenib with capecitabine, compared with capecitabine with placebo, did not prolong median PFS (5.5 vs. 5.4 months; hazard ratio [HR], 0.973; 95% confidence interval [CI], 0.779-1.217; P = .811) or overall survival (OS; 18.9 vs. 20.3 months; HR, 1.195; 95% CI, 0.943-1.513; P = .140); or enhance overall response rate (ORR; 13.5% vs. 15.5%; P = .515). Any grade toxicities (sorafenib vs. placebo) included palmar-plantar erythrodysesthesia syndrome (PPES; 79.2% vs. 59.6%), diarrhea (47.3% vs. 37.8%), mucosal inflammation (15.4% vs. 6.7%), and hypertension (26.2% vs. 5.6%). Grade 3/4 toxicities included PPES (15.4% vs. 7.1%), diarrhea (4.2% vs. 6.4%), and vomiting (3.5% vs. 0.7%).

CONCLUSION

The combination of sorafenib with capecitabine did not improve PFS, OS, or ORR in patients with HER2-negative advanced breast cancer. Rates of Grade 3 toxicities were higher in the sorafenib arm.

Overexpression of Antiangiogenic Vascular Endothelial Growth Factor Isoform and Splicing Regulatory Factors in Oral, Laryngeal and Pharyngeal Squamous Cell Carcinomas

Background:

Overexpression of proangiogenic vascular endothelial growth factor A family VEGFA_xxx is associated with tumor growth and metastasis. The role of the alternatively spliced antiangiogenic family VEGFA_xxxb is poorly investigated in head and neck squamous cell carcinomas (HNSCCs). The antiangiogenic isoform binds to bevacizumab and its expression level could influence the treatment response and progression-free survival. In this study, the relative expression of VEGFA_xxx and VEGFA₁₆₅b isoforms and splicing regulatory factors genes was investigated in a series of HNSCCs.

Methods:

VEGFA_xxx, VEGFA₁₆₅b, SRSF6, SRSF5, SRSF1 and SRPK1 gene expression was quantified by quantitative real time PCR in 53 tissue samples obtained by surgery from HNSCC patients. Protein expression was evaluated by immunohistochemistry.

Results:

VEGFA_xxx and VEGFA₁₆₅b were overexpressed in HNSCCs. Elevated protein expression was also confirmed. However, VEGFA isoforms demonstrated differential expression according to anatomical sites. VEGFA_xxx was overexpressed in pharyngeal tumors while the VEGFA₁₆₅b isoform was up-regulated in oral tumors. The VEGFA₁₆₅b isoform was also positively correlated with expression of the splicing regulatory genes SRSF1, SRSF6 and SRSF5.

Conclusions:

We concluded that VEGFA_xxx and VEGFA₁₆₅b isoforms are overexpressed in HNSCCs and the splicing regulatory factors SRSF1, SRSF6, SRSF5 and SRPK1 may contribute to alternative splicing of the VEGFA gene. The findings for the differential expression of the antiangiogenic isoform in HNSCCs could facilitate effective therapeutic strategies for the management of these tumors.

Up-to-date Doppler techniques for breast tumor vascularity: superb microvascular imaging and contrast-enhanced ultrasound

Ultrasonographic Doppler techniques have improved greatly over the years, allowing more sophisticated evaluation of breast tumor vascularity. Superb microvascular imaging (SMI) and contrast-enhanced ultrasound (CEUS) with second-generation contrast agents are two representative up-to-date techniques. SMI is a sensitive Doppler technique that adopts an intelligent filter system to separate low-flow signals from artifacts. With the development of second-generation contrast agents, CEUS has also emerged as a useful Doppler technique for evaluating tumor microcirculation. Both techniques can improve the diagnostic performance of gray-scale ultrasonography by providing vascular information useful not only for the morphologic assessment of microvessels, but also for the quantitative analysis of perfusion. In this review, we explain the imaging principles and previous research underlying these two vascular techniques, and describe our clinical experiences.

High-circulating Tie2 Is Associated With Pathologic Complete Response to Chemotherapy and Antiangiogenic Therapy in Breast Cancer

INTRODUCTION

Vascular endothelial growth factor (VEGF) is a central mediator of angiogenesis in breast cancer. Research in antiangiogenic cancer treatment has been marked by the development of the monoclonal antibody bevacizumab, which targets VEGF in many solid tumors. As patients do not equally benefit from bevacizumab, it has become necessary to define the profile of patients who will benefit from the drug.

MATERIALS AND METHODS

We have conducted a prospective phase II study in 39 patients using bevacizumab in breast cancer in the neoadjuvant setting, and found improved pathologic complete response (pCR) when bevacizumab was added to chemotherapy in patients with hormone receptor negative and invasive ductal carcinoma. Blood samples were collected at baseline and serially while patients were on treatment. Circulating angiogenesis-related proteins angiopoietin (ANG)1, ANG2, basic fibroblast growth factor, IL-1a, matrix metalloproteinase 9, platelet derived growth factor - BB, platelet endothelial cell adhesion molecule -1, Tie2, VEGF, and vascular endothelial growth factor receptor 2 were measured at baseline and during treatment. This correlative study was conducted to identify specific serum angiogenic factor profiles that might be associated with pCR in the neoadjuvant setting in breast cancer patients receiving bevacizumab and chemotherapy.

RESULTS

Elevated baseline serum Tie2 and basic fibroblast growth factor were associated with pCR in response to this combination. Changes in serum levels of these proteins were seen during treatment but were not significantly different between the pCR and non-pCR groups.

CONCLUSIONS

Baseline-circulating Tie2 levels may help distinguish patients who will have pCR from those who will not and may form the basis for future development of antiangiogenic therapy in breast cancer. Larger studies are needed to validate these findings. ClinicalTrials.gov Identifier: NCT00203502.

Overexpression of long non-coding RNA MEG3 suppresses breast cancer cell proliferation, invasion, and angiogenesis through AKT pathway

Long non-coding RNA MEG3 has been identified as a tumor suppressor which plays important roles in tumorigenesis; however, its potential role in breast cancer has not been fully examined. Here, we showed that MEG3 was downregulated in breast cancer tissues and cell lines. Overexpression of MEG3 inhibited breast cancer cell proliferation and invasion, suggesting that MEG3 played an important role in breast cancer progression and metastasis. Moreover, MEG3 upregulation caused marked inhibition of angiogenesis-related factor expression. Conditioned medium derived from MEG3 overexpressed breast cancer cells significantly decreased the capillary tube formation of endothelial cells. Furthermore, elevated expression of MEG3 in breast cancer inhibits in vivo tumorigenesis and angiogenesis in a nude mouse xenograft model. Mechanistically, overexpression of MEG3 results in downregulation of AKT signaling, which is pivotal for breast cancer cell growth, invasion, and tumor angiogenesis. Collectively, these results suggest that MEG3 might suppress the tumor growth and angiogenesis via AKT signaling pathway and MEG3 may serve as a potential novel diagnostic and therapeutic target of breast cancer.

Circulating levels of angiogenesis-related growth factors in breast cancer: A study to profile proteins responsible for tubule formation

The present study exploited a versatile in vitro endothelial cell/fibroblast co-culture cell system to investigate the association between angiogenesis and breast cancer by comparing the capacity of plasma from women with breast cancer and age-matched controls, to influence tubule formation and modulate angiogenesis in vitro, and to identify plasma circulating factors which might be responsible. Plasma from women with breast cancer (n=8) (added on day 7 after co-culture establishment) significantly increased tubule formation by 57% (P<0.01) when compared to cultures grown in culture medium lacking in vascular endothelial growth factor (VEGF) and fetal bovine serum (FBS), whereas plasma from controls (n=8) did not. Higher levels of VEGF, tumour necrosis factor-α (TNFα) and interleukin (IL)-6, but not leptin, were observed in plasma samples of the breast cancer group compared to the control group (n=20 in each group). In independent experiments, the effects of VEGF, TNFα, IL-6 and leptin were assessed and it was found that tubule formation was differentially affected whether these inflammatory cytokines or adipokines were added individually or in combination to the co-culture system. Using Proteome Profiler human angiogenesis array kits, 12 out of 55 angiogenesis-related proteins were differentially expressed in plasma from the breast cancer group compared to the control group. Pro-angiogenic proteins included: amphiregulin, artemin, coagulation factor III, fibroblast growth factor (FGF) acidic, GDNF, IL-8, macrophage inflammatory protein (MIP)-1α, platelet derived growth factor-AB/platelet derived growth factor-BB (PDGF-AB/PDGF-BB) and VEGF, whereas anti-angiogenic proteins were: angiopoietin-2, serpin F1 and serpin B5. In addition, FGF acidic was further identified as differentially expressed, with increased expression, when plasma samples from the normal and cancer groups, which induced an increase in tubule formation, were compared to one another. In conclusion, the present study identified angiogenesis-related proteins circulating in the serum of women with breast cancer that are likely to facilitate the growth and metastasis of breast cancer, in part through their influence on tubule formation, and, therefore, may be potential targets for new cancer therapies.

Role of Growth Hormone in Breast Cancer

Breast cancer is one of the most common cancers diagnosed in women. Approximately two-thirds of all breast cancers diagnosed are classified as hormone dependent, which indicates that hormones are the key factors that drive the growth of these breast cancers. Ovarian and pituitary hormones play a major role in the growth and development of normal mammary glands and breast cancer. In particular, the effect of the ovarian hormone estrogen has received much attention in regard to breast cancer. Pituitary hormones prolactin and growth hormone have also been associated with breast cancer. Although the role of these pituitary hormones in breast cancers has been studied, it has not been investigated extensively. In this review, we attempt to compile basic information from most of the currently available literature to understand and demonstrate the significance of growth hormone in breast cancer. Based on the available literature, it is clear that growth hormone plays a significant role in the development, progression, and metastasis of breast cancer by influencing tumor angiogenesis, stemness, and chemoresistance.

Identification of NCK1 as a novel downstream effector of STAT3 in colorectal cancer metastasis and angiogenesis

Signal transducer and activator of transcription 3 (STAT3) is known to activate targets associated with invasion, proliferation, and angiogenesis in a wide variety of cancers. The adaptor protein NCK1 is involved in cytoskeletal movement and was identified as a STAT3-associated target in human tumors. However, the underlying molecular mechanism associated with colorectal cancer (CRC) metastasis is not yet completely understood. In this study, we report a novel STAT3 to NCK1 signaling pathway in colorectal cancer (CRC). We investigated the expression of NCK1 and its potential clinical and biological significance in CRC. NCK1 was noticeably up-regulated in human CRC tissues. NCK1 was also significantly associated with serosal invasion, lymph metastasis, and tumor-node-metastasis classification but was inversely correlated with differentiation. Gain-of-function and loss-of-function studies have shown that ectopic expression of NCK1 enhanced metastasis and angiogenesis in CRC cells. By gene expression analyses, we revealed a high co-overexpression of STAT3 and NCK1 in CRC tissues. Ectopic overexpression of STAT3 in CRC cells induced the expression of NCK1, whereas STAT3 knockdown decreased the expression of NCK1. Promoter activation and binding analyses demonstrated that STAT3 promoted the expression of NCK1 via direct action on the NCK1 promoter. The knock down of NCK1 partially reduced the CRC cell metastasis and angiogenesis promoted by STAT3. Additionally, by co-immunoprecipitation assays, we verified that NCK1 interacted with PAK1, which resulted in the activation of the PAK1/ERK pathway. STAT3 induced the transcription of NCK1 and triggered a PAK1/ERK cascade in CRC. These findings suggest a novel STAT3 to NCK1 to PAK1/ERK signaling mechanism that is potentially critical for CRC metastasis and angiogenesis.

Modulation of mammary tumor vascularization by mast cells: Ultrasonographic and histopathological approaches

AIMS

The inhibition of mast cells' degranulation may be an approach to prevent the formation of new vessels during the mammary carcinogenesis.

MATERIALS AND METHODS

Female Sprague-Dawley rats were randomly divided into five experimental groups. Mammary tumors were induced by intraperitoneal injection of N-methyl-N-nitrosourea (MNU). Animals from group II were treated with ketotifen for 18weeks immediately after the MNU administration, while animals from group III only received the ketotifen after the development of the first mammary tumor. Mammary tumors vascularization was assessed by ultrasonography (Doppler, B Flow and contrast-enhanced ultrasound) and immunohistochemistry (vascular endothelial growth factor-A).

KEY FINDINGS AND SIGNIFICANCE

Similar to what occurs in women with breast cancer, the majority of MNU-induced mammary tumors exhibited a centripetal enhancement order of the contrast agent, clear margin and heterogeneous enhancement. Ultrasonographic and immunohistochemical data suggest that the inhibition of mast cells' degranulation did not change the mammary tumors vascularization.

Downregulation of transgelin blocks interleukin-8 utilization and suppresses vasculogenic mimicry in breast cancer cells

Vasculogenic mimicry (VM) is a non-classical mechanism recently described in many tumors, whereby cancer cells, rather than endothelial cells, form blood vessels. Transgelin is an actin-binding protein that has been implicated in multiple stages of cancer development. In this study, we investigated the role of transgelin in VM and assessed its effect on the expression of endothelial and angiogenesis-related genes during VM in MDA-MB-231 breast cancer cells. We confirmed the ability of MDA-MB-231 cells to undergo VM through a tube formation assay. Flow cytometry analysis revealed an increase in the expression of the endothelial-related markers VE-cadherin and CD34 in cells that underwent VM, compared with those growing in a monolayer, which was confirmed by immunocytochemistry. We employed siRNA to silence transgelin, and knockdown efficiency was determined by western blot analyses. Downregulation of transgelin suppressed cell proliferation and tube formation, but increased IL-8 levels in Matrigel cultures. RT-PCR analyses revealed that the expression of IL-8, VE-cadherin, and CD34 was unaffected by transgelin knockdown, indicating that increased IL-8 expression was not due to enhanced transcriptional activity. More importantly, the inhibition of IL-8/CXCR2 signaling also resulted in suppression of VM with increased IL-8 levels, confirming that increased IL-8 levels after transgelin knockdown was due to inhibition of IL-8 uptake. Our findings indicate that transgelin regulates VM by enhancing IL uptake. These observations are relevant to the future development of efficient antivascular agents. Impact statement Vasculogenic mimicry (VM) is an angiogenic-independent mechanism of blood vessel formation whereby aggressive tumor cells undergo formation of capillary-like structures. Thus, interventions aimed at angiogenesis might not target the entire tumor vasculature. A more holistic approach is therefore needed in the development of improved antivascular agents. Transgelin, an actin-binding protein, has been associated with multiple stages of cancer development such as proliferation, migration and invasion, but little is known about its role in vasculogenic mimicry. We present here, an additional mechanism by which transgelin promotes malignancy by way of its association with the occurrence of VM. Although transgelin knockdown did not affect the transcript levels of most of the angiogenesis-related genes in this study, it was associated with the inhibition of the uptake of IL-8, accompanied by suppressed VM, indicating that transgelin is required for VM. These observations are relevant to the future development of efficient antivascular agents.

Anti-angiogenic treatment in breast cancer: Facts, successes, failures and future perspectives

Angiogenesis is one of the hallmarks of cancer and a crucial requisite in the development of tumors. Interrupting this process by blocking the vascular endothelial growth factor (VEGF) with the monoclonal antibody bevacizumab has been considered a possible breakthrough in the treatment of various types of cancer, especially for advanced disease. However in breast cancer, studies have shown ambivalent results causing debate about the value of this drug. In this article, we review the evidence for anti-angiogenic treatment options for breast cancer, as well as discuss the possible factors limiting the effectiveness of anti-angiogenic agents and offer a recommendation regarding the future research on these therapies for the treatment of breast cancer.

Germline Genetic Variants in TEK, ANGPT1, ANGPT2, MMP9, FGF2 and VEGFA Are Associated with Pathologic Complete Response to Bevacizumab in Breast Cancer Patients

BACKGROUND

We previously reported improved pathologic complete response (pCR) in a prospective phase II study using neoadjuvant bevacizumab in combination with chemotherapy compared to chemotherapy alone in breast cancer patients (41% vs. 25%, p = 0.0291). In this study, we queried germline single-nucleotide polymorphisms (SNPs) in angiogenesis-related genes for their impact on pCR and overall survival (OS).

METHODS

DNA for genotyping was available from 34 subjects who received bevacizumab in addition to chemotherapy and 29 subjects who did not. Using Illumina® technology, we queried 504 SNPs with a minor allele frequency (MAF) of at least 5%, located in 10 angiogenesis-related genes, for their effect on pCR via logistic regression with an additive-inheritance model while adjusting for race and bevacizumab treatment. SNPs that showed significant associations with pCR were selected for additional characterization.

RESULTS

After adjusting for race and tumor type, patients who had bevacizumab added to their neoadjuvant therapy were found to experience a significantly improved rate of pCR compared to patients who did not (adjusted OR 8.40, 95% CI 1.90-37.1). When patients were analyzed for SNP effects via logistic regression with race and bevacizumab treatment included as covariates, two SNPs in angiopoietin 1 (ANGPT1), six in ANGPT2, three in fibroblast growth factor 2 (FGF2), four in matrix metalloproteinase 9 (MMP9), three in tyrosine kinase, endothelial (TEK) and two in vascular endothelial growth factor A (VEGFA) were associated with pCR (P<0.05). However, when overall survival was considered, there was no difference between treatment groups or between genotypes.

CONCLUSION

Genetic variability in TEK, ANGPT1, ANGPT2, FGF2, MMP9 and VEGFA is associated with pCR in bevacizumab-treated patients. Consistent with other studies, adding bevacizumab to standard chemotherapy did not impact OS, likely due to other factors and thus, while SNPs in TEK, ANGPT1, ANGPT2, FGF2, MMP9 and VEGFA were associated with pCR, they were not predictive of OS in this patient population.

TRIAL REGISTRATION

ClinicalTrials.gov NCT00203502.

Disrupting Tumor Angiogenesis and "the Hunger Games" for Breast Cancer

Angiogenesis, one of the hallmarks of cancers, has become an attractive target for cancer therapy since decades ago. It is broadly thought that upregulation of angiogenesis is involved in tumor progression and metastasis. Though tumor vessels are tortuous, disorganized, and leaky, they deliver oxygen and nutrients for tumor development. Based on this knowledge, many kinds of drugs targeting angiogenesis pathways have been developed, such as bevacizumab. However, the clinical outcomes of anti-angiogenesis therapies are moderate in metastatic breast cancer as well as in metastatic colorectal cancer and non-small cell lung cancer, even combined with traditional chemotherapy. In this chapter, the morphologic angiogenesis patterns and the key molecular pathways regulating angiogenesis are elaborated. The FDA-approved anti-angiogenesis drugs and current challenges of anti-angiogenesis therapy are described. The strategies to overcome the barriers will also be elucidated.

Deep tissue photoacoustic computed tomography with a fast and compact laser system

Photoacoustic computed tomography (PACT) holds great promise for biomedical imaging, but wide-spread implementation is impeded by the bulkiness of flash-lamp-pumped laser systems, which typically weigh between 50 - 200 kg, require continuous water cooling, and operate at a low repetition rate. Here, we demonstrate that compact lasers based on emerging diode technologies are well-suited for preclinical and clinical PACT. The diode-pumped laser used in this study had a miniature footprint (13 × 14 × 7 cm³), weighed only 1.6 kg, and outputted up to 80 mJ per pulse at 1064 nm. In vitro, the laser system readily provided over 4 cm PACT depth in chicken breast tissue. In vivo, in addition to high resolution, non-invasive brain imaging in living mice, the system can operate at 50 Hz, which enabled high-speed cross-sectional imaging of murine cardiac and respiratory function. The system also provided high quality, high-frame rate, and non-invasive three-dimensional mapping of arm, palm, and breast vasculature at multi centimeter depths in living human subjects, demonstrating the clinical viability of compact lasers for PACT.

Biomedical photoacoustics: fundamentals, instrumentation and perspectives on nanomedicine

Photoacoustic imaging (PAI) is an integrated biomedical imaging modality which combines the advantages of acoustic deep penetration and optical high sensitivity. It can provide functional and structural images with satisfactory resolution and contrast which could provide abundant pathological information for disease-oriented diagnosis. Therefore, it has found vast applications so far and become a powerful tool of precision nanomedicine. However, the investigation of PAI-based imaging nanomaterials is still in its infancy. This perspective article aims to summarize the developments in photoacoustic technologies and instrumentations in the past years, and more importantly, present a bright outlook for advanced PAI-based imaging nanomaterials as well as their emerging biomedical applications in nanomedicine. Current challenges and bottleneck issues have also been discussed and elucidated in this article to bring them to the attention of the readership.

VLDL and LDL, but not HDL, promote breast cancer cell proliferation, metastasis and angiogenesis

Abnormal lipoprotein profiles are associated with breast cancer progression. However, the mechanisms linking abnormal lipoprotein levels to breast cancer progression, especially metastasis, remain unclear. Herein, we found that L1 and L5 subfractions of LDL and VLDL, but not HDL, enhanced breast cancer cell viability. L1, L5, and VLDL also increased the in vitro tumorigenesis of breast cancer cells in anchorage-independent soft agar assay. In addition, L1, L5, and VLDL, but not HDL, increased the levels of mesenchymal markers Slug, Vimentin, and β-Catenin, and promoted breast cancer cell migration and invasion. L1, L5, and VLDL increased Akt Ser473 phosphorylation and promoted cell migration, which were reversed by the PI3K/Akt inhibitor wortmannin. Further in vitro angiogenesis assay and cytokine array analysis demonstrated that L1, L5, and VLDL enhanced secretion of angiogenic factors in breast cancer cells and promoted angiogenic activity. However, only VLDL reduced anchorage-dependent cell death and promoted lung metastasis in nude mice. In summary, our data suggest that L1, L5, and especially VLDL promote breast cancer progression and metastasis through Akt-induced EMT and angiogenesis, and provide a novel mechanism of how dyslipoproteinemia promotes breast cancer progression.

The expression pattern of matrix-producing tumor stroma is of prognostic importance in breast cancer

BACKGROUND

There are several indications that the composition of the tumor stroma can contribute to the malignancy of a tumor. Here we utilized expression data sets to identify metagenes that may serve as surrogate marker for the extent of matrix production and vascularization of a tumor and to characterize prognostic molecular components of the stroma.

METHODS

TCGA data sets from six cancer forms, two breast cancer microarray sets and one mRNA data set of xenografted tumors were downloaded. Using the mean correlation as distance measure compact clusters with genes representing extracellular matrix production (ECM metagene) and vascularization (endothelial metagene) were defined. Explorative Cox modeling was used to identify prognostic stromal gene sets.

RESULTS

Clustering of stromal genes in six cancer data sets resulted in metagenes, each containing three genes, representing matrix production and vascularization. The ECM metagene was associated with poor prognosis in renal clear cell carcinoma and in lung adenocarcinoma but not in other cancers investigated. Explorative Cox modeling using gene pairs identified gene sets that in multivariate models were prognostic in breast cancer. This was validated in two microarray sets. Two notable genes are TCF4 and P4HA3 which were included in the sets associated with positive and negative prognosis, respectively. Data from laser-microdissected tumors, a xenografted tumor data set and from correlation analyses demonstrate the stroma specificity of the genes.

CONCLUSIONS

It is possible to construct ECM and endothelial metagenes common for several cancer forms. The molecular composition of matrix-producing cells, rather than the extent of matrix production seem to be important for breast cancer prognosis.

Towards Dynamic Contrast Specific Ultrasound Tomography

We report on the first study demonstrating the ability of a recently-developed, contrast-enhanced, ultrasound imaging method, referred to as cumulative phase delay imaging (CPDI), to image and quantify ultrasound contrast agent (UCA) kinetics. Unlike standard ultrasound tomography, which exploits changes in speed of sound and attenuation, CPDI is based on a marker specific to UCAs, thus enabling dynamic contrast-specific ultrasound tomography (DCS-UST). For breast imaging, DCS-UST will lead to a more practical, faster, and less operator-dependent imaging procedure compared to standard echo-contrast, while preserving accurate imaging of contrast kinetics. Moreover, a linear relation between CPD values and ultrasound second-harmonic intensity was measured (coefficient of determination = 0.87). DCS-UST can find clinical applications as a diagnostic method for breast cancer localization, adding important features to multi-parametric ultrasound tomography of the breast.

Evaluation of Curcumin Capped Copper Nanoparticles as Possible Inhibitors of Human Breast Cancer Cells and Angiogenesis: a Comparative Study with Native Curcumin

Synthesis of metal nanoparticles for improving therapeutic index and drug delivery is coming up as an attractive strategy in the mainstream of cancer therapeutic research. In the present study, curcumin-capped copper nanoparticles (CU-NPs) were evaluated as possible inhibitors of in vivo angiogenesis, pro-angiogenic cytokines involved in promoting tumor angiogenesis along with inhibition of cell proliferation and migration of breast cancer cell line MDA-MB-231. The antiangiogenic potential was assessed using in vivo chorioallantoic membrane (CAM) model. 3-(4, 5-Dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT)-based cytotoxicity assay was used to assess the effect of CU-NPs against proliferation of breast cancer cell line. The wound healing migration assay was used to evaluate the effects of CU-NPs on the migration ability of breast cancer cell line. Native curcumin (CU) was used as a reference compound for comparison purpose. The result of the present investigation indicates that CU-NPs could not demonstrate impressive antiangiogenic or anticancer activities significantly as compared to native CU. The possible mechanisms of experimental outcomes are discussed in the light of the methods of nanoparticle synthesis in concert with the current state of the art literature.

Molecular expression of vascular endothelial growth factor, prokineticin receptor-1 and other biomarkers in infiltrating canalicular carcinoma of the breast

Vascular endothelial growth factor (VEGF) is important in the growth and metastasis of cancer cells. In 2001, another angiogenic factor, endocrine gland-derived VEGF (EG-VEGF), was characterized and sequenced. EG-VEGF activity appears to be restricted to endothelial cells derived from endocrine glands. At the molecular level, its expression is regulated by hypoxia and steroid hormones. Although VEGF and EG-VEGF are structurally different, they function in a coordinated fashion. Since the majority of mammary tumors are hormone-dependent, it was hypothesized that EG-VEGF would be expressed in these tumors, and therefore, represent a potential target for anti-angiogenic therapy. The aim of the present study was to assess the expression of VEGF, EG-VEGF and its receptor (prokineticin receptor-1), as well as that of breast cancer resistant protein, estrogen receptor, progesterone receptor and human epidermal growth factor receptor 2, in 50 breast samples of infiltrating canalicular carcinoma (ICC) and their correlation with tumor staging. The samples were analyzed using reverse transcription-quantitative polymerase chain reaction and immunohistochemistry. Both angiogenic growth factors were identified in all samples. However, in 90% of the samples, the expression level of VEGF was significantly higher than that of EG-VEGF (P=0.024). There was no association between the expression of VEGF, EG-VEGF or its receptor with tumor stage. In ICC, the predominant angiogenic factor expressed was VEGF. The expression level of either factor was not correlated with the tumor-node-metastasis stage. Although ICC is derived from endothelial cells, EG-VEGF expression was not the predominant angiogenic/growth factor in ICC.