Expression of the vascular endothelial growth factor receptor-2/Flk-1 in breast carcinomas: correlation with proliferation

Correlation between quantitative parameters of CEUS and Ki-67 labeling index in soft-tissue sarcoma

BACKGROUND

Apart from the immunohistochemical Ki-67 labeling index (LI), clinicians need a non-invasive and convenient way to predict the prognosis of patients with soft-tissue sarcoma (STS).

PURPOSE

To investigate the correlation between quantitative parameters of contrast-enhanced ultrasound (CEUS) and Ki-67 LI in STS.

MATERIAL AND METHODS

A total of 25 patients diagnosed with STS who underwent CEUS examination using SonoVue®, between January 2019 to November 2020, were included in the study. They were then divided into a high-proliferation group and low-proliferation group according to 30% Ki-67 positive tumor cells. The quantitative parameters in the semi-automatic time intensity curve analysis software, including arrival time, time to peak, peak intensity, rise time (RT), rise slope, 50% wash-out time, and 50% wash-out intensity, were extracted from the time intensity curve of CEUS by two independent observers. Statistical evaluation of the correlation and difference between CEUS quantitative parameters and Ki-67 LI between the two groups was performed. According to the area under the curve (AUC) analysis, optimal cutoff points of parameters with significant difference were determined.

RESULTS

CEUS RT of the high-proliferation group in STS was significantly higher than that of the low-proliferation group (ρ = 0.509, P = 0.01). The most reasonable cutoff to distinguish between low- and high-proliferation groups was 10.84 s. The sensitivity, specificity, and the AUC were 86.7%, 80%, and 0.80, respectively.

CONCLUSION

CEUS RT was correlated with Ki-67 LI of STS, which can be used as a minimally invasive auxiliary tool to predict the prognosis of STS in clinical practice.

Characterization of the Expression of Angiogenic Factors in Cutaneous Squamous Cell Carcinoma of Domestic Cats

Cutaneous squamous cell carcinoma (CSCC) is a common malignant skin cancer with a significant impact on health, and it is important to determine the degree of reliance of CSCC on angiogenesis for growth and metastasis. Major regulators of angiogenesis are the vascular endothelial growth factor (VEGF) family and their associated receptors. Alternative pre-mRNA splicing produces multiple isoforms of VEGF-A and PLGF with distinct biological properties. Several studies highlight the function of VEGF-A in CSCC, but there are no studies of the different isoforms of VEGF-A and PLGF for this neoplasm. We characterized the expression of three isoforms of VEGF-A, two isoforms of PLGF, and their receptors in cat CSCC biopsies compared to normal haired skin (NHS). Although our results revealed no significant changes in transcript levels of panVEGF-A or their isoforms, the mRNA levels of PLGF I and the receptors Flt-1 and KDR were downregulated in CSCC compared to NHS. Differences were observed in ligand:receptor mRNA expression ratio, with the expression of VEGF-A relative to its receptor KDR higher in CSCC, which is consistent with our hypothesis and prior human SCC studies. Immunolocalization in tissue showed increased expression of all measured factors and receptors in tumor cells compared to NHS and surrounding vasculature. We conclude that the factors measured may play a pivotal role in CSCC growth, although further studies are needed to clarify the role of angiogenic factors in feline CSCC.

Identification of biomarkers associated with cervical lymph node metastasis in papillary thyroid carcinoma: Evidence from an integrated bioinformatic analysis

Integrated analysis of accumulated data is an effective way to obtain reliable potential diagnostic molecular of cervical lymph node metastases (LNM) in papillary thyroid carcinoma (PTC). The benefits of prophylactic lymph node dissection (PLND) for these clinically node-negative (cN0) patients remained considerable controversies. Hence, elucidation of the mechanisms of LNM and exploration of potential biomarkers and prognostic indicators are essential for accurate diagnosis of LNM in PTC patients. Up to date, advanced microarray and bioinformatics analysis have advanced an understanding of the molecular mechanisms of disease occurrence and development, which are necessary to explore genetic changes and identify potential diagnostic biomarkers. In present study, we performed a comprehensive analysis of the differential expression, biological functions, and interactions of LNM-related genes. Two publicly available microarray datasets GSE60542 and GSE129562 were available from Gene Expression Omnibus (GEO) database. Differentially expressed genes between clinically node-positive (cN1) and cN0 PTC samples were screened by an integrated analysis of multiple gene expression profile after gene reannotation and batch normalization. Our results identified 48 differentially expressed genes (DEGs) genetically associated with LNM in PTC patients. Gene ontology (GO) analyses revealed the changes in the modules were mostly enriched in the regulation of MHC class II receptor activity, the immune receptor activity, and the peptide antigen binding. Kyoto encyclopedia of genes and genomes (KEGG) enrichment analysis of DEGs displayed the intestinal immune network for IgA production, staphylococcus aureus infection, and cell adhesion molecules (CAMs). To screen core genes related to LNM of PTC from the protein-protein interaction network, top 10 hub genes were identified with highest scores. Our results help us understand the exact mechanisms underlying the metastasis of cervical LNM in PTC tissues and pave an avenue for the progress of precise medicine for individual patients.

Relationship Between Ultrasound Features and Ki-67 Labeling Index of Soft Tissue Sarcoma

Objectives

To explore the relationship between ultrasound (US) features and Ki-67 labeling index (LI) of soft tissue sarcoma (STS).

Methods

Forty-six patients with 47 STS lesions, between September 2014 and April 2020, were enrolled in the study. Point-biserial correlation analysis and Spearman’s correlation analysis were utilized to examining the relationship between the US features and the Ki-67 LI of STS. The differences of US features between high and low Ki-67 proliferation groups were statistically analyzed by independent t test, Wilcoxon rank-sum test, and Fisher’s exact test. The optimal cut-off points of US features revealing significant differences were estimated by the maximum Youden index.

Results

A moderate correlation between the vascular density grade and the Ki-67 LI (ρ = 0.409, P = 0.004) was found in this study. In addition, other ultrasound features were irrelevant to the Ki-67 LI. The cut-off for differentiating low- and high-proliferation groups was grade II according to the best Youden index. The area under receiver operating characteristic (ROC) curve was 0.74 (p = 0.011) with a sensitivity of 60.6% and specificity of 78.6%.

Conclusions

Only the vascular density grade of STS had a weak positive correlation with Ki-67 LI, and might be capable of predicting the proliferation of STS. Other ultrasonographic features of STS such as shape and tumor margin have no correlation with Ki-67 LI.

The Value of Nomograms in Pre-Operative Prediction of Lymphovascular Invasion in Primary Breast Cancer Undergoing Modified Radical Surgery: Based on Multiparametric Ultrasound and Clinicopathologic Indicators

The purpose of this study was to explore the value of pre-operative prediction of lymphovascular invasion (LVI) in primary breast cancer patients undergoing modified radical mastectomy and to develop a nomogram based on multiparametric ultrasound and clinicopathologic indicators. All patients with primary breast cancer confirmed by pre-operative biopsy underwent B-mode ultrasound and contrast-enhanced ultrasound examinations. Post-operative pathology was used as the gold standard to identify LVI. Lasso regression was used to select predictors most related to LVI. A nomogram was developed to calculate the diagnostic efficacy. We bootstrapped the data for 500 times to perform internal verification, drawing a calibration curve to verify prediction ability. A total of 244 primary breast cancer patients were included. LVI was observed in 77 patients. Ten predictors associated with LVI were selected by Lasso regression. The area under the curve, sensitivity, specificity and accuracy for the nomogram were 0.918, 92.2%, 76.7% and 81.6%, respectively. And the nomogram calibration curve showed good consistency between the predicted probability and the actual probability. The nomogram developed could be used to predict LVI in primary breast cancer patients undergoing modified radical mastectomy and to help in clinical decision-making.

The role of contrast-enhanced ultrasound in the diagnosis of malignant non-mass breast lesions and exploration of diagnostic criteria

OBJECTIVES

To assess the value of contrast-enhanced ultrasound (CEUS) for diagnosing malignant non-mass breast lesions (NMLs) and to explore the CEUS diagnostic criteria.

METHODS

A total of 116 patients with 119 NMLs detected by conventional US were enrolled. Histopathological results were used as the reference standard. The enhancement characteristics of NMLs in CEUS were compared between malignant and benign NMLs. The CEUS diagnostic criteria for malignant NMLs were established using independent diagnostic indicators identified by binary logistic regression analysis. The diagnostic performance of Breast Imaging Reporting and Data System-US (BI-RADS-US), CEUS, and BI-RADS-US combined with CEUS was evaluated and compared.

RESULTS

Histopathological results showed 63 and 56 benign and malignant NMLs. Enhancement degree (OR = 5.75, p = 0.003), enhancement area (OR = 4.25, p = 0.005), and radial or penetrating vessels (OR = 7.54, p = 0.003) were independent diagnostic indicators included to establish the CEUS diagnostic criteria. The sensitivity and specificity of BI-RADS-US, CEUS, and BI-RADS-US combined with CEUS were 100 and 30.2%, 80.4 and 74.6%, and 94.6 and 77.8%, respectively; the corresponding areas under the receiver operating characteristic curve (AUC) were 0.819, 0.775, and 0.885, respectively.

CONCLUSIONS

CEUS has a high specificity in malignant NML diagnosis based on the diagnostic criteria including enhancement degree, enhancement area, and radial or penetrating vessels, but with lower sensitivity than BI-RADS-US. The combination of CEUS and BI-RADS-US is an effective diagnostic tool with both high sensitivity and specificity for the diagnosis of malignant NMLs.

ADVANCES IN KNOWLEDGE

In this study, we assessed the diagnostic value of CEUS for malignant NMLs and constructed a feasible diagnostic criterion. We further revealed that the combination of CEUS and BI-RADS-US has a high diagnostic value for malignant NMLs.

Modified Model for Diagnosing Breast Imaging Reporting and Data System Category 3 to 5 Breast Lesions: Retrospective Analysis and Nomogram Development

OBJECTIVES

The aim of this study was to explore a modified model to simplify the diagnostic process for American College of Radiology Breast Imaging Reporting and Data System category 3 to 5 breast lesions and evaluate the model's diagnostic efficacy.

METHODS

A retrospective review was conducted of breast lesions examined by B-mode ultrasound (US) and contrast-enhanced ultrasound (CEUS) and diagnosed by histopathologic examination from October 2016 to August 2019. The US characteristics of a combined model (US + CEUS model) with relatively high diagnostic value were selected by a lasso regression analysis to establish a modified model. Two nomograms were developed. The results were internally validated by bootstrap resampling.

RESULTS

Overall, 206 breast lesions in 198 patients, 136 benign and 70 malignant, were included. Ultrasound characteristics included in the modified model were shape, margin, microcalcification, enhanced intensity, enhanced scope, and enhanced time. For the US + CEUS model and modified model, sensitivities were 94.3% and 93.3%; specificities were 85.9% and 81.4%; accuracies were 89.3% and 88.7% and areas under the curve were 0.957 and 0.944, respectively. No statistically significant differences were seen in the diagnostic efficacies of the models (P = .097). Bootstrap-corrected sensitivities, specificities. and accuracies of the models were consistent with these results. Bootstrap-corrected areas under the curve for the US + CEUS model and the modified model were 0.955 and 0.940, respectively.

CONCLUSIONS

The modified model with fewer indicators conveniently and effectively diagnosed the malignancy of Breast Imaging Reporting and Data System category 3 to 5 breast lesions without reducing diagnostic efficacy.

Utility of quantitative contrast-enhanced ultrasound for the prediction of lymph node metastasis in patients with papillary thyroid carcinoma

OBJECTIVES

The aim of this study was to find the optimal parameters and cutoffs to differentiate metastatic lymph nodes (LNs) from benign LNs in the patients with papillary thyroid carcinoma (PTC) on the quantitative contrast-enhanced ultrasound (CEUS) features.

METHODS

A total of 134 LNs in 105 patients with PTCs were retrospectively enrolled. All LNs were evaluated by conventional ultrasound (US) and CEUS before biopsy or surgery. The diagnostic efficacy of CEUS parameters was analyzed.

RESULTS

Univariate analysis indicated that metastatic LNs more often manifested centripetal or asynchronous perfusion, hyper-enhancement, heterogeneous enhancement, ring-enhancing margins, higher PI, larger AUC, longer TTP and DT/2 than benign LNs at pre-operative CEUS (p <  0.001, for all). Multivariate analysis showed that centripetal or asynchronous perfusion (OR = 3.163; 95% CI, 1.721-5.812), hyper-enhancement(OR = 0.371; 95% CI, 0.150-0.917), DT/2 (OR = 7.408; 95% confidence interval CI, 1.496-36.673), and AUC (OR = 8.340; 95% CI, 2.677-25.984) were predictive for the presence of metastatic LNs. The sensitivity and accuracy of the quantitative CEUS were higher than qualitative CEUS (75% vs 55 % and 83.6% vs 76.1 % , respectively).

CONCLUSIONS

Quantitative CEUS parameters can provide more information to distinguish metastatic from benign LNs in PTC patients; In particular, DT/2 and AUC have a higher sensitivity and accuracy in predicting the presence of metastatic LNs and reduce unnecessary sampling of benign LNs.

Old Player-New Tricks: Non Angiogenic Effects of the VEGF/VEGFR Pathway in Cancer

Angiogenesis has long been considered to facilitate and sustain cancer growth, making the introduction of anti-angiogenic agents that disrupt the vascular endothelial growth factor/receptor (VEGF/VEGFR) pathway an important milestone at the beginning of the 21st century. Originally research on VEGF signaling focused on its survival and mitogenic effects towards endothelial cells, with moderate so far success of anti-angiogenic therapy. However, VEGF can have multiple effects on additional cell types including immune and tumor cells, by directly influencing and promoting tumor cell survival, proliferation and invasion and contributing to an immunosuppressive microenvironment. In this review, we summarize the effects of the VEGF/VEGFR pathway on non-endothelial cells and the resulting implications of anti-angiogenic agents that include direct inhibition of tumor cell growth and immunostimulatory functions. Finally, we present how previously unappreciated studies on VEGF biology, that have demonstrated immunomodulatory properties and tumor regression by disrupting the VEGF/VEGFR pathway, now provide the scientific basis for new combinational treatments of immunotherapy with anti-angiogenic agents.

Application of Contrast-Enhanced Ultrasound in the Diagnosis of Ductal Carcinoma In Situ: Analysis of 127 Cases

OBJECTIVES

To explore the characteristics of breast ductal carcinoma in situ (DCIS) on real-time grayscale contrast-enhanced ultrasound (CEUS) imaging and the diagnostic value of CEUS in DCIS.

METHODS

A total of 127 histopathologically confirmed DCIS lesions and 124 fibroadenomas (FAs; controls) were subjected to conventional ultrasound and CEUS. Next, the CEUS findings of DCIS and FA lesions, including morphologic features and quantitative parameters, were analyzed.

RESULTS

Binary logistic regression was used to identify the independent risk factors from DCIS and FA lesions detected by CEUS. Contrast-enhanced ultrasound revealed significant differences between DCIS and FA. The wash-in time, enhancement mode, enhancement intensity, blood perfusion defects, peripheral high enhancement, enhancement scope, intratumoral vessels and their courses and dilatation degree, and penetrating vessels on CEUS were identified as features correlated with DCIS (P < .05). Moreover, a multivariate logistic regression analysis was developed, and the area under receiver operating characteristic curve of each index was generated, including the wash-in time, enhancement intensity, blood perfusion defects, enhancement scope, penetrating vessels, arrival time, and peak intensity (P < .05; area under the curve, >0.6).

CONCLUSIONS

The contrast-enhancement patterns and DCIS parameters appeared different from FA lesions, thus suggesting that CEUS can be very useful in distinguishing DCIS from FA lesions.

Application of contrast-enhanced ultrasound in the diagnosis of small breast lesions

BACKGROUND

Breast cancer is the most common cancer in women worldwide. The purpose of the study was to observe the features of contrast-enhanced ultrasound (CEUS) and the combination with Breast Imaging-Reporting and Data System (BI-RADS) of conventional ultrasound for assessing small breast lesions.

OBJECTIVES

The study was to explore the small breast lesions' features of contrast-enhanced ultrasound (CEUS) and the combination with Breast Imaging-Reporting and Data System (BI-RADS) of conventional ultrasound, in order to improve the diagnostic accuracy of early breast cancer.

METHODS

105 lesions were subject to conventional US (ultrasound) and CEUS before operations or biopsies. Among 105 breast lesions, six patient diagnoses were established by thick core-needle biopsy, while the rest were all confirmed by surgery and pathology.

RESULTS

Significant differences were found between benign and malignant lesions in qualitative and quantitative indexes (peak) of CEUS (P < 0.05). The qualitative features of malignant small breast lesions were as follows: (1) enhanced intensity within the lesion was not uniform (61/61,100%); (2) the speed of wash-in was earlier than the surrounding tissue (58/61, 95.1%); (3) lesion interior and the surrounding tissues had contrast vessel performance (61/61,100%). Peak of malignant lesions (35.77±11.45) was higher than that of benign lesions (31.96±10.76) (P < 0.05). The diagnostic performance of BI-RADS-US plus qualitative indexes (method one) in terms of area under receiver operating characteristic curve (AUROC) were the highest (i.e., AUROC = 0.817), in comparison with other combined diagnostic methods. The associated sensitivity, specificity and accuracy were 78.69%, 84.09% and 80.95%, respectively. With method one, however, was similar with US-BI-RADS in specificity, 11 malignant breast lesions were regarded as a higher classification of BI-RADS and classified into malignant group, which were identified as benign on US-BI-RADS originally.

CONCLUSIONS

CEUS was useful to differentiate benign from malignant small breast lesions, and the combination of CEUS and BI-RADS-US can improve the early diagnosis of breast cancers.

Anti-cancer effects of F16: A novel vascular endothelial growth factor receptor-specific inhibitor

Vascular endothelial growth factor receptor-2 is a dynamic target for therapeutic intervention in various types of cancers. This study was aimed to explore the anti-angiogenic activity of a novel vascular endothelial growth factor receptor-specific inhibitor named F16 in both in vitro and in vivo experimental models. This compound effectively reduced cell proliferation, tube formation, and migration of human umbilical vein endothelial cells in a concentration-dependent manner by directly inhibiting vascular endothelial growth factor binding and subsequent vascular endothelial growth factor receptor-2 phosphorylation. The F16 was also able to inhibit the phosphoinositide 3-kinase/protein kinase B-mediated survival and migration pathways in cancer in addition to inhibiting the focal adhesion kinase and mitogen-activated protein kinases-mediated signaling in GI-101A cancer cells. The chorioallantoic membrane assay followed by tumor growth inhibition measurements with GI-101A breast cancer xenograft implanted athymic nude mice confirmed the in vivo tumor reductive effects of F16. It was interesting to observe a decrease in tumor burden after F16 treatment which correlated very well with the decrease in the plasma levels of mucin-1 (MUC-1). Our studies so far have confirmed that F16 is a specific inhibitor of angiogenesis in both in vitro and in vivo models. The F16 also works very efficiently with Taxol in combination by limiting the tumor growth that is better than the monotherapy with any one of the drugs that were tested individually. Thus, F16 offers a promising anti-proliferative and anti-angiogenic effects with better specificity than some of the existing multi-kinase inhibitors.

Differential expression of VEGFR2 protein in HER2 positive primary human breast cancer: potential relevance to anti-angiogenic therapies

Background

Clinically relevant predictive biomarkers to tailor anti-angiogenic therapies to breast cancer (BRC) patient subpopulations are an unmet need.

Methods

We analyzed tumor vascular density and VEGFR2 protein expression in various subsets of primary human BRCs (186 females; Mean age: 59 years; range 33–88 years), using a tissue microarray. Discrete VEGFR2+ and CD34+ tumor vessels were manually scored in invasive ductal, lobular, mixed ductal-lobular and colloid (N = 139, 22, 18, 7) BRC cores.

Results

The observed CD34+ and VEGFR2+ tumor vascular counts in individual cases were heterogeneous. Mean CD34+ and VEGFR2+ tumor vessel counts were 11 and 3.4 per tumor TMA core respectively. Eighty-nine of 186 (48%) cases had >10 CD34+ tumor vessels, while 97/186 (52%) had fewer CD34+ vessels in each TMA core. Of 169 analyzable cores in the VEGFR2 stained TMA, 90 (53%) showed 1–5 VEGFR2+ tumor vessels/TMA core, while 42/169 (25%) cores had no detectable VEGFR2+ tumor vessels. Thirteen of 169 (8%) cases also showed tumor cell (cytoplasmic/membrane) expression of VEGFR2. Triple-negative breast cancers (TNBCs) appeared to be less vascular (Mean VD = 9.8, range 0–34) than other breast cancer subtypes. Overall, VEGFR2+ tumor vessel counts were significantly higher in HER2+ as compared to HR+ (p = 0.04) and TNBC (p = 0.02) tissues. Compared to HER2− cases, HER2+ breast cancers had higher VEGFR2+ tumor vessel counts (p = 0.007).

Conclusion

Characterization of pathologic angiogenesis in HER2+ breast cancer provides scientific rationale for future investigation of clinical activity of agents targeting the VEGF/VEGFR2 axis in this clinically aggressive breast cancer subtype.

Immunoglobulin-like domain 4-mediated ligand-independent dimerization triggers VEGFR-2 activation in HUVECs and VEGFR2-positive breast cancer cells

PURPOSE

The extracellular region (EC) of the vascular endothelial growth factor (VEGF) receptor-2 (VEGFR-2) contains seven immunoglobulin-like (Ig-like) domains that are required for specific ligand binding and receptor dimerization. Studies of domain 4-7 deletions and substitutions provided insights into the interaction between receptors in the absence of VEGF. In this study, we investigated the effect of domain 4 in ligand-independent VEGFR-2 dimerization and activation in human vascular endothelial cells and human breast cancer cells.

METHODS

To confirm the role of domain 4 in ligand-independent receptor dimerization and activation, two VEGFR-2 fragments with and without domain 4, KFP1 and KFP2, were generated by recombinant DNA technology. We measured the affinity of KFP1 and KFP2 with VEGFR-2, and the roles of KFP1 and FKP2 in dimerization and phosphorylation of VEGFR-2. We also evaluated the effect of KFP1 and FKP2 on cell proliferation and migration in HUVECs and in human breast cancer cells.

RESULTS

We showed that KFP1 did not affect the interaction of VEGFR-2 and VEGF but bound VEGFR-2 in the absence of VEGF. Furthermore, cross-linking and cross-linking immunoblotting demonstrated that KFP1 could form a complex with VEGFR-2, which resulted in VEGFR-2 dimerization in the absence of VEGF. Importantly, we found that the KDR fragment with domain 4 induced phosphorylation of VEGFR-2, as well as phosphorylation of downstream receptor kinases in HUVECs and VEGFR-2-positive breast cancer cells. Consistent with these results, this ligand-independent activation of VEGFR-2 also promoted downstream signaling and cell proliferation and migration.

CONCLUSIONS

The domain 4 of VEGFR-2 plays an important role in the interaction between VEGFR receptors in the absence of VEGF.

Immunohistochemical Expression of Vascular Endothelial Growth Factor and Vascular Endothelial Growth Factor Receptor Associated with Tumor Cell Proliferation in Canine Cutaneous Squamous Cell Carcinomas and Trichoepitheliomas

The expression of 5 markers associated with angiogenesis was studied in canine squamous cell carcinomas (SCCs) ( n = 19) and canine trichoepitheliomas (TCPs) ( n = 24). SCCs were assigned histologic grades, and tissue sections from both tumor types were immunohistochemially stained for the expression of vascular endothelial growth factor (VEGF), vascular endothelial growth factor receptor-2 (VEGFR-2), as well as intratumoral microvessel density (iMVD), tumor proliferation index (PI), and tumor apoptotic index (AI), using antibodies against VEGF, VEGFR-2, von Willebrand's factor, Ki-67 antigen, and the terminal deoxynucleotidyl transferase-mediated 2′-deoxyuridine 5′-triphosphate endlabeling method (TUNEL), respectively. VEGF and VEGFR-2 were detected in 17/19 (89.4%) and 19/19 (100%) SCCs and in 17/24 (70.8%) and 20/24 (83.3%) TCPs, respectively. In SCCs, there was substantial correlation between histologic grade and PI ( r = 0.51); and moderate correlation between VEGF and histologic grade ( r = 0.43), VEGFR-2 and histologic grade ( r = 0.47), VEGF and PI ( r = 0.47), and VEGFR-2 and PI ( r = 0.47) (Spearman rank correlation coefficient). In TCPs, there was substantial correlation between VEGF and PI ( r = 0.51) and a moderate correlation between VEGFR-2 and iMVD ( r = 0.36). The median iMVD of SCCs (15.5) was significantly higher than the median iMVD of TCPs (9.05) ( P value < .05). It was concluded that VEGF and VEGFR-2 may promote tumor cell proliferation in TCPs and SCCs. An autocrine pathway for VEGF probably operates in canine SCCs and TCPs, as VEGF and VEGFR-2 expression was found in most tumors and was associated with evidence for tumor cell proliferation.

Qualitative, quantitative and combination score systems in differential diagnosis of breast lesions by contrast-enhanced ultrasound

OBJECTIVE

To assess the feasibility of score systems in differential diagnosis of breast lesions by contrast-enhanced ultrasound (CEUS).

METHODS

CEUS was performed in 121 patients with 127 breast lesions by Philips iU22 with Sonovue as contrast agent. Pearson Chi-square χ(2) test, binary logistic regression analysis and Student's t-test are used to identify significant CEUS parameters in differential diagnosis. Based on these significant CEUS parameters, qualitative, quantitative and combination score systems were built by scoring 1 for benign characteristic and scoring 2 for malignant characteristic. Receiver operating characteristic (ROC) curve was applied to evaluate the diagnostic efficacy of different analytical methods.

RESULTS

Pathological results showed 41 benign and 86 malignant lesions. Qualitative analysis and logistic regression analysis showed that there are significant differences in enhancement degree, enhancement order, internal homogeneity, enhancement margin, surrounding vessels and enlargement of diameters (P<0.05) between benign and malignant lesions. Quantitative analysis indicated that malignant lesions tended to show higher peak intensity (PI), larger area under the curve (AUC) and shorter time to peak (TTP) than benign ones (P<0.05). Qualitative score systems showed higher diagnostic efficacy than single quantitative CEUS parameters. The corresponding area under the ROC curve for qualitative, quantitative and combination score systems were 0.897, 0.716 and 0.903 respectively. Z test showed that area under the ROC curve of quantitative score system was statistically smaller than that of other score systems.

CONCLUSIONS

Quantitative score system helps little in improving the diagnostic efficacy of CEUS. While qualitative score system improves the performance of CEUS greatly in discrimination of benign and malignant breast lesions. The application of qualitative could develop the diagnostic performance of CEUS which is clinically promising.

Molecular mechanisms of hormone resistance of breast cancer

More than 70% malignant mammary tumors contain steroid hormone receptors; this suggests the possibility of hormone therapy in the majority of patients with breast cancer (BC). The main cause of inefficiency of hormone therapy in BC is hormone resistance (tumor resistance to hormonal cytostatics). Here we discuss the main mechanisms of hormone resistance of BC and the mechanisms underlying the formation of hormone resistance of the tumors are analyzed at the molecular level. The data on the signal pathways of estrogen receptors (ER), the key regulators of BC cell proliferation, are presented. The most important factors of BC hormone resistance are: high activity/expression of receptor tyrosine kinases; high activity of proteins regulating cell defense mechanisms (Akt PI3K, mTOR); changes in the activities of cell cycle regulator proteins (Myc, c-Fos, Cyclin D1). Our experiments have demonstrated that estrogen-independent BC cell growth is supported by VEGF/VEGFR2 and EGF/EGFR mitogenic signal pathways. Our data indicate that NF-kappaB transcription factor is directly involved in the regulation of hormone-resistant BC cell growth and survival, while NF-kappaB suppression determines cell sensitivity to apoptotic activity of antitumor compounds. On the whole, the results indicate good prospects of using EGFR, HER-2/neu, mTOR, VEGFR, PI3K/Akt molecular pathways as targets for BC therapy, including therapy for BC resistant forms.

VEGFR-2 expression in malignant tumours of the canine mammary gland: a prospective survival study

Vascular endothelial growth factor receptor-2 (VEGFR-2) is the main receptor activated by vascular endothelial growth factor -A (VEGF-A) to promote tumour angiogenesis. Its clinical prognostic value has not been studied in canine mammary tumours (CMTs). Dogs with mammary cancer were enrolled in a survival study and the immunohistochemical expressions of VEGFR-2 and VEGF-A were analysed and associated with clinicopathological features. VEGFR-2 expression was associated with VEGF immunoreactivity in cancer cells, supporting the presence of an autocrine loop that may be involved in CMTs growth and survival. VEGFR-2 was also expressed by endothelial cells from tumour vasculature and positively associated with stromal matrix metalloproteinase-9 (MMP-9), suggesting the existence of a link between endothelial cells activation and up-regulation of matrix degrading proteins. Carcinosarcomas exhibited high VEGFR-2 expression suggesting that it may be one of the activated molecular pathways in this aggressive histological type and that VEGFR-2 inhibitors may constitute a potential treatment to improve the prognosis of these patients. Both VEGF and VEGFR-2 immunoreactivities were independent of patients' overall survival (OS) and disease-free survival (DFS).

Contrast-enhanced ultrasound characteristics of breast cancer: correlation with prognostic factors

The purpose of the work described here was to investigate the correlation of contrast-enhanced ultrasound (CEUS) characteristics with prognostic factors in breast cancer. Forty-five consecutive breast cancer patients were studied with CEUS. All patients were diagnosed with invasive ductal carcinoma on the basis of biopsy or surgery results. Lack of blood perfusion of the tumor was identified in 2 cases; blood perfusion was observed in 43 cases. Enhancement was heterogeneous in 25 cases, and centripetal in 25 cases. A blood perfusion defect was present in 27 cases. Enhancement shape was irregular in 37 cases, margins were poorly defined in 34 cases, and penetrating vessels were present in 32 cases. Compared with the surrounding normal tissue, tumor tissue had faster rising times and times to peak and higher peak intensities and wash-in slopes; the differences between the two groups were statistically significant (p < 0.05). Compared with the interior of the tumor, the periphery had faster times to peak and higher peak intensities and wash-in slopes (p < 0.05). Heterogeneous enhancement, perfusion defect, centripetal enhancement and penetrating vessels were correlated with prognosis (p < 0.05). Overall, some CEUS characteristics of breast cancer were associated with prognostic factors that can predict breast cancer prognosis in vivo.

Immunohistochemical investigation of the angiogenic proteins VEGF, HIF-1α and CD34 in invasive ductal carcinoma of the breast

The expression of prognostic markers in cancer has become important in diagnostic routine and research. A high mitotic rate compromises the individual cell access to oxygen and nutrients, due to reduced blood supply. Cells undertake adaptive measures such as vascular endothelial growth factor (VEGF), expressed under the control of hypoxia-inducible factor-1α (HIF-1α). CD34 is an endothelial marker which can show the presence and distribution of blood vessels. This study evaluated the presence and relative expression of VEGF, HIF-1α and CD34 using immunohistochemistry of 60 breast tumors and double staining, correlating the findings with clinical and pathological variables. High VEGF expression was correlated with low cell proliferation, lymph node-negative, smaller tumor size and patients not receiving hormone therapy. High HIF-1α expression predominated in younger (<50-year) patients, subjected to neo-adjuvant therapy and in p53-negative tumors. Absence of metastasis, radiotherapy or hormone treatment, and estrogen receptor (ER)-positive tumors showed high CD34 immunoreactivity. We suggest that the angiogenic factors VEGF, HIF-1α and CD34 are important in breast cancer progression and their abundance in breast tumors has prognostic and predictive value.

Prior exposure to chemotherapy: a marker of sensitivity and selection for antiangiogenic therapy in breast cancer?

The identification of patients who are more likely to derive benefit from antiangiogenic therapy is a key to refine patient selection and so maximize clinical benefit, and reduce unnecessary treatment costs. Improved patient selection will equally be effective in minimizing the exposure of non-eligible patients to ineffectual treatment which could be associated with adverse effects as well as delaying effective treatment. Herein, we review the literature from clinical trials suggesting that the addition of antiangiogenic agents to chemotherapy for the treatment of HER-2 negative metastatic breast cancer in patients previously exposed to chemotherapy may deliver differential therapeutic benefit and may serve as a selection criteria in the current absence of a robust biomarker.

VEGF targets the tumour cell

The function of vascular endothelial growth factor (VEGF) in cancer is not limited to angiogenesis and vascular permeability. VEGF-mediated signalling occurs in tumour cells, and this signalling contributes to key aspects of tumorigenesis, including the function of cancer stem cells and tumour initiation. In addition to VEGF receptor tyrosine kinases, the neuropilins are crucial for mediating the effects of VEGF on tumour cells, primarily because of their ability to regulate the function and the trafficking of growth factor receptors and integrins. This has important implications for our understanding of tumour biology and for the development of more effective therapeutic approaches.

Tyrosine kinase inhibitors (TKIs) in human and pet tumours with special reference to breast cancer: a comparative review

Tyrosine kinase receptors (TKRs) play a key role in tumour cell proliferation and survival since they are involved in endothelial cell activation leading to tumour neoangiogenesis. In particular, vascular endothelial growth factor receptors (VEGFRs), platelet-derived growth factor receptor (PDGFR), stem cell factor receptor (c-KitR), and colony-stimulating factor 1 (CSF-1) are overexpressed or constitutively activated in human and pet malignancies. A variety of small molecule inhibitors targeting specific tyrosine kinases (known as tyrosine kinase inhibitors or TKIs) have recently been approved, or are under investigation, for the treatment of human cancer. TKI application in animal cancer is however relatively recent. This review aims to illustrate the major aspects of tyrosine kinase dysfunctions, with special regard to human and animal cancer of the mammary gland, providing an update on the background of the anti-angiogenic and anti-neoplastic properties of TKIs in human and veterinary cancer.

Insulin-like growth factor receptor I (IGF-IR) and vascular endothelial growth factor receptor 2 (VEGFR-2) are expressed on the circulating epithelial tumor cells of breast cancer patients

BACKGROUND

Circulating epithelial tumor cell (CETC) analysis is a promising diagnostic field for estimating the risk for metastatic relapse and progression in patients with malignant disease. CETCs characterization can be used as a liquid biopsy for prognostic and predictive purposes in breast and other cancers. IGF-IR and VEGFR-2 play an important role in tumor growth and the progression of cancer disease. The purpose of the current study was therefore to investigate their expression on CETCs.

METHODS

CETCs were determined from the blood of 50 patients suffering from breast cancer. The number of vital CETCs and the expression of IGF-IR and VEGFR-2 were investigated using the maintrac® method.

RESULTS

IGF-IR and VEGFR-2 expression on the surface of CETCs were detected in 84% of patients. A statistically high correlation was found between IGF-IR and VEGFR-2 (r = 0.745 and p<0.001) on the CETCs. The co-expression of both receptors was confirmed in some experiments and ranged between 70% and 100%. Statistically significant correlations were observed between the number of CETCs and IGF-IR (r = 0.315 and p<0.05) and VEGFR-2 (r = 0.310 and p<0.05) expression. The presence of CETCs and the level of IGF-IR and VEGFR-2 expression were not associated with tumor stage, hormone receptor status or nodal/distant metastasis.

SUMMARY

In this study, a parallel and co-expression of IGF-IR and VEGFR-2 was examined on the surface of CETCs in breast cancer patients for the first time. Characterization of CETCs may be a promising approach for the rational design of targeted anticancer therapies.

Earlier detection of breast cancer with ultrasound molecular imaging in a transgenic mouse model

While there is an increasing role of ultrasound for breast cancer screening in patients with dense breast, conventional anatomical ultrasound lacks sensitivity and specificity for early breast cancer detection. In this study, we assessed the potential of ultrasound molecular imaging using clinically translatable vascular endothelial growth factor receptor type 2 (VEGFR2)-targeted microbubbles (MB(VEGFR2)) to improve the diagnostic accuracy of ultrasound in earlier detection of breast cancer and ductal carcinoma in situ (DCIS) in a transgenic mouse model [FVB/N-Tg(MMTV-PyMT)634Mul]. In vivo binding specificity studies (n = 26 tumors) showed that ultrasound imaging signal was significantly higher (P < 0.001) using MB(VEGFR2) than nontargeted microbubbles and imaging signal significantly decreased (P < 0.001) by blocking antibodies. Ultrasound molecular imaging signal significantly increased (P < 0.001) when breast tissue (n = 315 glands) progressed from normal [1.65 ± 0.17 arbitrary units (a.u.)] to hyperplasia (4.21 ± 1.16), DCIS (15.95 ± 1.31), and invasive cancer (78.1 ± 6.31) and highly correlated with ex vivo VEGFR2 expression [R(2) = 0.84; 95% confidence interval (CI), 0.72-0.91; P < 0.001]. At an imaging signal threshold of 4.6 a.u., ultrasound molecular imaging differentiated benign from malignant entities with a sensitivity of 84% (95% CI, 78-88) and specificity of 89% (95% CI, 81-94). In a prospective screening trail (n = 63 glands), diagnostic performance of detecting DCIS and breast cancer was assessed and two independent readers correctly diagnosed malignant disease in more than 95% of cases and highly agreed between each other [intraclass correlation coefficient (ICC) = 0.98; 95% CI, 97-99]. These results suggest that VEGFR2-targeted ultrasound molecular imaging allows highly accurate detection of DCIS and breast cancer in transgenic mice and may be a promising approach for early breast cancer detection in women.

Promoting melanoma growth and metastasis by enhancing VEGF expression

Angiogenesis plays an essential role in tumor growth and metastasis and is a promising target for cancer therapy. Vascular endothelial growth factor (VEGF) is a key regulator of angiogenesis. The present study was designed to determine the role of VEGF in tumor growth and metastasis. The sequences for the VEGF gene were cloned into expression plasmids and then transfected into melanoma B16 cells. Overexpression of VEGF transfected with expression plasmids or given exogenous VEGF and epidermal growth factor (EGF) significantly enhanced tumor cell proliferation, migration, and invasion. Tumor growth and metastasis of melanoma B16 cells transfected with VEGF plasmid were significantly promoted compared with those of cells administered with exogenous VEGF or EGF. These results indicated that VEGF can be an effective antiangiogenic strategy for melanoma.

Tubular network formation by adriamycin-resistant MCF-7 breast cancer cells is closely linked to MMP-9 and VEGFR-2/VEGFR-3 over-expressions

We have previously demonstrated that matrix metalloproteinase-9 (MMP-9) is critical for breast cancer cell migration and is necessary but not sufficient for tubular network formation. Given the important angiogenic activity of vascular endothelial growth factor (VEGF), we investigate here its possible contribution in tubular network formation and its link with MMP-9. Exposure of resistant epithelial breast cancer cells (rMCF-7) to Avastin, a VEGF neutralising antibody, suppresses tubular network formation but not cell migration. However, their exposure to MMP-9 inhibitor markedly decreases both parameters. Besides, the addition of exogenous VEGF or MMP-9 alone or in combination to sensitive parental cells (sMCF-7) or rMCF-7 cells enhances tubular network formation by rMCF-7 cells but not by sMCF-7 cells. The evaluation of the expression levels of VEGF receptor (VEGFR) subtypes shows that sMCF-7 cells express only small quantities of VEGFR-2 and VEGFR-3 compared with rMCF-7 cells that express strong quantities. However, treatment of sMCF-7 cells by phorbol 12-myristate 13-acetate (PMA), a PKC activator, induces both tubular network formation and VEGFR-2/VEGFR-3 over-expressions. Interestingly, exposure of rMCF-7 cells or PMA-treated sMCF-7 cells to the specific inhibitors of VEGFR-2 and VEGFR-3 reduces markedly the tubular network formation. Together, our results demonstrate that the proteolytic enzyme MMP-9 promotes rMCF-7 cell migration and, consequently, tubular network formation through VEGFR-2/ VEGFR-3 activation. Understanding of mechanisms involved in vasculogenic mimicry and cell migration related to MMP-9 and VEGF may open new opportunities to improve cancer therapy.

Cytotoxicity of VEGF(121)/rGel on vascular endothelial cells resulting in inhibition of angiogenesis is mediated via VEGFR-2

Background

The fusion protein VEGF₁₂₁/rGel composed of the growth factor VEGF₁₂₁ and the plant toxin gelonin targets the tumor neovasculature and exerts impressive anti-vascular effects. We have previously shown that VEGF₁₂₁/rGel is cytotoxic to endothelial cells overexpressing VEGFR-2 but not to endothelial cells overexpressing VEGFR-1. In this study, we examined the basis for the specific toxicity of this construct and assessed its intracellular effects in vitro and in vivo.

Methods

We investigated the binding, cytotoxicity and internalization profile of VEGF₁₂₁/rGel on endothelial cells expressing VEGFR-1 or VEGFR-2, identified its effects on angiogenesis models in vitro and ex vivo, and explored its intracellular effects on a number of molecular pathways using microarray analysis.

Results

Incubation of PAE/VEGFR-2 and PAE/VEGFR-1 cells with ¹²⁵I-VEGF₁₂₁/rGel demonstrated binding specificity that was competed with unlabeled VEGF₁₂₁/rGel but not with unlabeled gelonin. Assessment of the effect of VEGF₁₂₁/rGel on blocking tube formation in vitro revealed a 100-fold difference in IC₅₀ levels between PAE/VEGFR-2 (1 nM) and PAE/VEGFR-1 (100 nM) cells. VEGF₁₂₁/rGel entered PAE/VEGFR-2 cells within one hour of treatment but was not detected in PAE/VEGFR-1 cells up to 24 hours after treatment. In vascularization studies using chicken chorioallantoic membranes, 1 nM VEGF₁₂₁/rGel completely inhibited bFGF-stimulated neovascular growth. The cytotoxic effects of VEGF₁₂₁/rGel were not apoptotic since treated cells were TUNEL-negative with no evidence of PARP cleavage or alteration in the protein levels of select apoptotic markers. Microarray analysis of VEGF₁₂₁/rGel-treated HUVECs revealed the upregulation of a unique "fingerprint" profile of 22 genes that control cell adhesion, apoptosis, transcription regulation, chemotaxis, and inflammatory response.

Conclusions

Taken together, these data confirm the selectivity of VEGF₁₂₁/rGel for VEGFR-2-overexpressing endothelial cells and represent the first analysis of genes governing intoxication of mammalian endothelial cells by a gelonin-based targeted therapeutic agent.

Concomitant vascular GRP-receptor and VEGF-receptor expression in human tumors: molecular basis for dual targeting of tumoral vasculature

Gastrin-releasing peptide (GRP) and GRP receptors (GRPR) play a role in tumor angiogenesis. Recently, GRPR were found to be frequently expressed in the vasculature of a large variety of human cancers. Here, we characterize these GRPR by comparing the vascular GRPR expression and localization in a selection of human cancers with that of an established biological marker of neoangiogenesis, the vascular endothelial growth factor (VEGF) receptor. In vitro quantitative receptor autoradiography was performed in parallel for GRPR and VEGF receptors (VEGFR) in 32 human tumors of various origins, using ¹²⁵I-Tyr-bombesin and ¹²⁵I-VEGF₁₆₅ as radioligands, respectively. Moreover, VEGFR-2 was evaluated immunohistochemically. All tumors expressed GRPR and VEGFR in their vascular system. VEGFR were expressed in the endothelium in the majority of the vessels. GRPR were expressed in a subpopulation of vessels, preferably in their muscular coat. The vessels expressing GRPR were all VEGFR-positive whereas the VEGFR-expressing vessels were not all GRPR-positive. GRPR expressing vessels were found immunohistochemically to co-express VEGFR-2. Remarkably, the density of vascular GRPR was much higher than that of VEGFR. The concomitant expression of GRPR with VEGFR appears to be a frequent phenomenon in many human cancers. The GRPR, localized and expressed in extremely high density in a subgroup of vessels, may function as target for antiangiogenic tumor therapy or angiodestructive targeted radiotherapy with radiolabeled bombesin analogs alone, or preferably together with VEGFR targeted therapy.

Notch, IL-1 and leptin crosstalk outcome (NILCO) is critical for leptin-induced proliferation, migration and VEGF/VEGFR-2 expression in breast cancer

High levels of pro-angiogenic factors, leptin, IL-1, Notch and VEGF (ligands and receptors), are found in breast cancer, which is commonly correlated with metastasis and lower survival of patients. We have previously reported that leptin induces the growth of breast cancer and the expression of VEGF/VEGFR-2 and IL-1 system. We hypothesized that Notch, IL-1 and leptin crosstalk outcome (NILCO) plays an essential role in the regulation of leptin-mediated induction of proliferation/migration and expression of pro-angiogenic molecules in breast cancer. To test this hypothesis, leptin's effects on the expression and activation of Notch signaling pathway and VEGF/VEGFR-2/IL-1 were determined in mouse (4T1, EMT6 and MMT) breast cancer cells. Remarkably, leptin up-regulated Notch1-4/JAG1/Dll-4, Notch target genes: Hey2 and survivin, together with IL-1 and VEGF/VEGFR-2. RNA knockdown and pharmacological inhibitors of leptin signaling significantly abrogated activity of reporter gene-luciferase CSL (RBP-Jk) promoter, showing that it was linked to leptin-activated JAK2/STAT3, MAPK, PI-3K/mTOR, p38 and JNK signaling pathways. Interestingly, leptin upregulatory effects on cell proliferation/migration and pro-angiogenic factors Notch, IL-1 and VEGF/VEGFR-2 were abrogated by a γ-secretase inhibitor, DAPT, as well as siRNA against CSL. In addition, blockade of IL-1R tI inhibited leptin-induced Notch, Hey2 and survivin as well as VEGF/VEGFR-2 expression. These data suggest leptin is an inducer of Notch (expression/activation) and IL-1 signaling modulates leptin effects on Notch and VEGF/VEGFR-2. We show for the first time that a novel unveiled crosstalk between Notch, IL-1 and leptin (NILCO) occurs in breast cancer. Leptin induction of proliferation/migration and upregulation of VEGF/VEGFR-2 in breast cancer cells were related to an intact Notch signaling axis. NILCO could represent the integration of developmental, pro-inflammatory and pro-angiogenic signals critical for leptin-induced cell proliferation/migration and regulation of VEGF/VEGFR-2 in breast cancer. Targeting NILCO might help to design new pharmacological strategies aimed at controlling breast cancer growth and angiogenesis.

Randomized, Placebo-Controlled, Double-Blind, Phase II Study of Axitinib Plus Docetaxel Versus Docetaxel Plus Placebo in Patients With Metastatic Breast Cancer

Purpose

This multicenter, randomized, double-blind, phase II study assessed safety and efficacy of axitinib plus docetaxel in metastatic breast cancer (MBC).

Patients and Methods

Women with MBC were randomly assigned 2:1 to receive docetaxel 80 mg/m2 once every 3 weeks plus axitinib 5 mg twice per day (combination arm) or placebo (placebo arm), following a lead-in phase I trial. The primary end point was time to progression (TTP).

Results

In all, 168 patients were enrolled; 112 were randomly assigned to axitinib and 56 to placebo. Median TTP was numerically longer in the combination arm than in the placebo arm (8.1 v 7.1 months), but this difference was not statistically significant (hazard ratio, 1.24; 95% CI, 0.82 to 1.87; one-sided P = .156). The difference in median TTP was greatest among patients who had received prior adjuvant chemotherapy (9.2 v 7.0 months; P = .043, prespecified subgroup analysis). Objective response rate was higher in the combination arm (41.1% v 23.6%; P = .011). The most common grades 3 to 4 treatment-related adverse events (combination/placebo) included diarrhea (10.8%/0%), fatigue (10.8%/5.4%), stomatitis (12.6%/1.8%), mucositis (9.0%/0%), asthenia (7.2%/0%), and hypertension (4.5%/0%). Three patients in the combination arm experienced serious thromboembolic events (one death). Febrile neutropenia was more frequent in the combination arm (15.3% v 7.1%); rates of other hematologic toxicities were comparable. Increased toxicity with axitinib was generally managed by dose reduction and/or growth factor support.

Conclusion

The addition of axitinib to docetaxel did not improve TTP in first-line MBC treatment. Combination therapy may be more effective in patients previously exposed to adjuvant chemotherapy.

Immunohistochemical study of the angiogenetic network of VEGF, HIF1α, VEGFR-2 and endothelial nitric oxide synthase (eNOS) in human breast cancer

BACKGROUND

The role of Nitric Oxide (NO) in angiogenesis has not been fully clarified yet. A dual role for NO, either inductive or inhibitory, has been proposed on the basis of different effects that high or low concentrations of NO may exert on the angiogenic process. Additionally, it has been referred that NO may induce VEGF production, while VEGF may induce NO production via up-regulation of the endothelial nitric oxide synthase (eNOS), the two pathways being reverse. The aim of the current study was to investigate the expression of key molecules involved in these opposite pathways in primary breast cancer.

METHODS

Representative tumor samples from 242 patients with early-stage breast cancer (invasive ductal breast carcinomas) were investigated for the expression of VEGF, VEGFR-2, HIF1α, iNOS, and eNOS using immunohistochemistry.

RESULTS

Endothelial NOS was found in 159 cases, VEGF in 131 cases, HIF-1α in 139 cases, VEGFR2 in 185 cases and inducible NOS (iNOS) in 22 cases. There was a significant correlation between the expression of VEGF and VEGFR-2, eNOS and VEGF, eNOS and VEGFR-2, eNOS and HIF1α. No statistically significant correlation was found between iNOS and the rest of the studied molecules.

CONCLUSIONS

In breast cancer cases, the major molecules regulating NO and VEGF production can be co-expressed in the individual carcinomas implying a possibility for the relevant pathways to be active; however appropriate functional experiments remain to be conducted to prove such a hypothesis.

Triple-negative breast cancer: a short review

This review describes the pathology, prognosis, current treatment options, and future directions for the management of patients with triple-negative breast cancer. "Triple-negative" tumors lack expression of estrogen and progesterone receptors, and HER2. The subtype comprises some 15% of all breast cancers, with tumors of a typically larger size and higher grade. Clinically, triple-negative breast cancer has a relatively high rate of recurrence and distant metastasis, and poor overall survival. The standard of care is chemotherapy, although recent research suggests a sound rationale for the use of targeted agents with antitumor and/or antiangiogenic activity such as receptor tyrosine kinase inhibitors.

Breast cancer genomics based on biobanks

Attempts to find genes contribution to complex diseases, such as cancer, require new study designs which incorporate an efficient use of population resources and modern genotyping technologies. We describe here two approaches, used by us for the study of breast cancer, both of which take the use of biobanks. One uses a cancer registry as a source of case information, which is then linked to a biobank on blood DNA. The biobank provides also samples from matched controls. After genotyping, clinical data are retrieved from hospital records, and the results can be presented for genotype-specific cancer risks, or similarly for genotype-specific clinical and survival parameters. The second approach uses registered data on cancer in families or among twins. On defined groups of patients, paraffin tissue is collected by contacting the pathology departments of the hospitals where the patients were diagnosed. Tumor and healthy tissue is prepared and used for mutation, the loss of heterozygosity, or copy number analysis. We believe that in the era of whole-genome genotyping technologies, the importance of well-characterized sample sets cannot be overemphasized. Samples rather than technologies limit the rate of gene discovery in complex diseases.

A phase II study of pazopanib in patients with recurrent or metastatic invasive breast carcinoma: a trial of the Princess Margaret Hospital phase II consortium

PURPOSE

Angiogenesis is an important hallmark of breast cancer growth and progression. Pazopanib, an oral small molecule inhibitor of vascular endothelial growth factor receptor, platelet-derived growth factor receptor, and KIT, has activity across a range of solid tumors. We evaluated the activity of single-agent pazopanib in recurrent or metastatic breast cancer (MBC).

PATIENTS AND METHODS

Patients with recurrent breast cancer or MBC, treated with up to two prior lines of chemotherapy, were eligible to receive pazopanib, 800 mg daily until progression. The primary endpoint was the objective response rate as measured by Response Evaluation Criteria in Solid Tumors. Secondary endpoints included time to progression, the stable disease rate, and toxicity. Using a two-stage design, confirmed response in three of 18 patients was required to proceed to stage 2.

RESULTS

Twenty evaluable patients were treated, with a median age of 56 years; 70% were estrogen receptor positive, all were human epidermal growth factor receptor 2 negative. The majority had one or two prior lines of chemotherapy. One patient (5%) had a partial response, 11 (55%) had stable disease (SD) [four (20%) with SD > or = 6 months], and seven (35%) had progressive disease as their best response. One (5%) was not evaluable. The median time to progression was 5.3 months. Pazopanib did not cause significant severe toxicity aside from grade 3-4 transaminitis, hypertension, and neutropenia in three patients each (14% each) and grade 3 gastrointestinal hemorrhage in one patient (5%).

CONCLUSION

Pazopanib provides disease stability in advanced breast cancer. The activity seen is comparable with that of other antiangiogenic agents in this setting. Pazopanib may be of interest for future studies in breast cancer, including in combination with other systemic agents.

Vascular endothelial growth factor receptor-2 in breast cancer

Investigations over the last decade have established the essential role of growth factors and their receptors during angiogenesis and carcinogenesis. The vascular endothelial growth factor receptor (VEGFR) family in mammals contains three members, VEGFR-1 (Flt-1), VEGFR-2 (KDR/Flk-1) and VEGFR-3 (Flt-4), which are transmembrane tyrosine kinase receptors that regulate the formation of blood and lymphatic vessels. In the early 1990s, the above VEGFR was structurally characterized by cDNA cloning. Among these three receptors, VEGFR-2 is generally recognized to have a principal role in mediating VEGF-induced responses. VEGFR-2 is considered as the earliest marker for endothelial cell development. Importantly, VEGFR-2 directly regulates tumor angiogenesis. Therefore, several inhibitors of VEGFR-2 have been developed and many of them are now in clinical trials. In addition to targeting endothelial cells, the VEGF/VEGFR-2 system works as an essential autocrine/paracrine process for cancer cell proliferation and survival. Recent studies mark the continuous and increased interest in this related, but distinct, function of VEGF/VEGFR-2 in cancer cells: the autocrine/paracrine loop. Several mechanisms regulate VEGFR-2 levels and modulate its role in tumor angiogenesis and physiologic functions, i.e.: cellular localization/trafficking, regulation of cis-elements of promoter, epigenetic regulation and signaling from Notch, cytokines/growth factors and estrogen, etc. In this review, we will focus on updated information regarding VEGFR-2 research with respect to the molecular mechanisms of VEGFR-2 regulation in human breast cancer. Investigations in the activation, function, and regulation of VEGFR-2 in breast cancer will allow the development of new pharmacological strategies aimed at directly targeting cancer cell proliferation and survival.

Tumor angiogenesis and novel antiangiogenic strategies

Angiogenesis is essential for the development and growth of tumors. It is a highly regulated process that requires cross-talk between signaling pathways at all stages of blood vessel development and tumor growth, from the recruitment of endothelial cells to vessel maturation. This review summarizes tumor angiogenesis and describes the key signaling pathways governing blood vessel development. The role of angiogenesis in various tumor types is discussed, but the focus is on invasive breast cancer, a disease that will affect approximately 182,000 women in the USA in 2008. Research efforts over the past decade have identified numerous potential, as well as proven therapies with activity in breast cancer. These include chemotherapeutics as well as therapies that inhibit specific angiogenic pathways known as targeted agents. Some of the data from single- and multitargeted antiangiogenic agents are described in this review. "Published 2008 Wiley-Liss, Inc. This article is a US Government work, and, as such, is in the public domain in the United States of America."

An exploratory study of sunitinib plus paclitaxel as first-line treatment for patients with advanced breast cancer

Background: Sunitinib has shown single-agent activity in patients with previously treated metastatic breast cancer (MBC). We investigated the safety of the combination of sunitinib and paclitaxel in an exploratory study of patients with locally advanced or MBC.

Methods: Patients received oral sunitinib 25 mg/day (with escalation to 37.5 mg/day as tolerated) on a continuous daily dosing schedule and paclitaxel 90 mg/m² on days 1, 8, and 15 of each 28-day cycle. Study endpoints included safety (primary endpoint), pharmacokinetics, and antitumor activity.

Results: Twenty-two patients were enrolled. The most frequent adverse events (AEs) were fatigue/asthenia (77%), dysgeusia (68%), and diarrhea (64%). Grade 3 AEs included neutropenia (43%), fatigue/asthenia (27%), neuropathy (18%), and diarrhea (14%). No drug–drug interaction was observed on the basis of pharmacokinetic analysis. Of 18 patients with measurable disease at baseline, 7 (38.9%) achieved objective responses (including 2 complete and 5 partial responses). Clinical responses were observed in three of nine patients with triple-negative receptor status (estrogen receptor negative, progesterone receptor negative, and human epidermal growth factor receptor-2 negative).

Conclusions: These data indicate that sunitinib and paclitaxel in combination are well tolerated in patients with locally advanced or MBC. No drug–drug interaction was detected and there was preliminary evidence of antitumor activity.

Growth factor receptors and apoptosis regulators: signaling pathways, prognosis, chemosensitivity and treatment outcomes of breast cancer

Biomarkers of breast cancer are necessary for prognosis and prediction to chemotherapy. Prognostic biomarkers provide information regarding outcome irrespective of therapy, while predictive biomarkers provide information regarding response to therapy. Candidate prognostic biomarkers for breast cancers are growth factor receptors, steroid receptors, Ki-67, cyclins, urokinase plasminogen activator, p53, p21, pro- and anti-apoptotic factors, BRCA1 and BRCA2. But currently, the predictive markers are Estrogen and Progesterone receptors responding to endocrine therapy, and HER-2 responding to herceptin. But there are numerous breast cancer cases, where tamoxifen is ineffective even after estrogen receptor positivity. This lead to search of new prognostic and predictive markers and the number of potential markers is constantly increasing due to proteomics and genomics studies. However, most biomarkers individually have poor sensitivity or specificity, or other clinical value. It can be resolved by studying various biomarkers simultaneously, which will help in better prognosis and increasing sensitivity for chemotherapeutic agents. This review is focusing on growth factor receptors, apoptosis markers, signaling cascades, and their correlation with other associated biomarkers in breast cancers. As our knowledge regarding molecular biomarkers for breast cancer increases, prognostic indices will be developed that combine the predictive power of individual molecular biomarkers with specific clinical and pathologic factors. Rigorous comparison of these existing as well as emerging markers with current treatment selection is likely to see an escalation in an era of personalized medicines to ensure the breast cancer patients receive optimal treatment. This will also solve the treatment modalities and complications related to chemotherapeutic regimens.

Immunohistochemical expression of vascular endothelial growth factor and vascular endothelial growth factor receptor in canine cutaneous fibrosarcomas

The expression of five markers associated with tumour angiogenesis, proliferation and apoptosis was studied in 24 canine cutaneous fibrosarcomas. Tumours were assigned histological grades and were immunohistochemically evaluated for the expression of vascular endothelial growth factor (VEGF) and vascular endothelial growth factor receptor-2 (VEGFR-2). Additionally, intra-tumour microvessel density (iMVD) was assessed by immunohistochemical labelling for expression of von Willebrand factor (vWf) and tumour proliferation index (PI) was measured following labelling of Ki-67 antigen. Finally, tumour apoptotic index (AI) was determined by application of the terminal deoxynucleotidyl transferase (TdT)-mediated dUTP end-labelling method (TUNEL). VEGF and VEGFR-2 expression were detected in 22/24 (92%) and 24/24 (100%) of fibrosarcomas, respectively. There was correlation between VEGF and VEGFR-2 expression (r = 0.51) and between histological grade and PI (r = 0.82). A significant difference in PI between tumours of different histological grade was found (P < 0.05). The median PI in grade 2 and 3 tumours (30.6 and 54.7, respectively) was significantly higher than in grade 1 tumours (6.4). Therefore, only PI correlates significantly with the histological grade of canine cutaneous fibrosarcomas. The potential for autocrine activity for VEGF exists in canine cutaneous fibrosarcomas, as VEGF and VEGFR-2 expression was found in most tumours.

A specific vascular endothelial growth factor receptor tyrosine kinase inhibitor enhances the antiproliferative effect of trastuzumab in human epidermal growth factor receptor 2 overexpressing breast cancer cell lines

BACKGROUND

Trastuzumab has been found to have potent antiproliferative effects in human epidermal growth factor receptor 2 (HER-2)-overexpressing human breast tumors. Inhibition of vascular endothelial growth factor receptor (VEGFR), a protein often overexpressed in breast carcinoma, has been shown to induce apoptosis.

METHODS

Breast carcinoma cell lines were cultured with increasing doses of trastuzumab and/or a VEGFR tyrosine kinase inhibitor (TKI). Growth inhibition and apoptosis were assessed after 5 days and 48 hours of treatment, respectively. Combination index values were calculated to determine the effectiveness of this drug combination.

RESULTS

A dose-dependent growth inhibition was shown in all cell lines tested with the VEGFR TKI, whereas trastuzumab was effective only in the HER-2-positive cells. A synergistic interaction was shown in the HER-2-overexpressing cell lines, accompanied by an increase in apoptosis.

CONCLUSIONS

The combination of trastuzumab and a VEGFR TKI may be of therapeutic value in select breast cancer patients.

Inhibiting colorectal carcinoma growth and metastasis by blocking the expression of VEGF using RNA interference

Angiogenesis plays an essential role in tumor growth and metastasis and is a promising target for cancer therapy. Vascular endothelial growth factor (VEGF) is a key regulator of angiogenesis. The present study was designed to determine the role of VEGF in tumor growth and metastasis using RNA interference (RNAi) technology. Four small interfering RNA (siRNA) sequences for the VEGF gene were cloned into expression plasmids and transfected into human colorectal carcinoma (CRC) SW620 cells. Stable transfection of these plasmids decreased VEGF protein expression, leading to the potent suppression of tumor cell proliferation, migration, invasion, and angiogenesis in vitro. Furthermore, in subcutaneous and intrasplenic/portal injection models involving athymic nude mice, the tumor growth and metastasis of SW620 cells expressing VEGF siRNA were significantly inhibited compared with untransfected cells or cells transfected with control vector alone. Immunohistochemical analyses of tumor sections revealed a decreased vessel density and decreased VEGF expression in the animals where siRNA against VEGF were expressed. These results indicate that RNAi of VEGF can be an effective antiangiogenic strategy for CRC.