Second international consensus on the methodology and criteria of evaluation of angiogenesis quantification in solid human tumours

Knockdown of Merm1/Wbscr22 attenuates sensitivity of H460 non-small cell lung cancer cells to SN-38 and 5-FU without alteration to p53 expression levels

Merm1/Wbscr22 is a novel metastasis promoter that has been shown to be involved in tumor metastasis, viability and apoptosis. To the best of our knowledge, there are currently no studies suggesting the possible correlation between the expression of Merm1/Wbscr22 in tumor cells and chemosensitivity to antitumor agents. In the present study, two human non-small cell lung cancer cell lines, H1299 and H460, were used to investigate whether Merm1/Wbscr22 affects chemosensitivity to antitumor agents, including cisplatin (CDDP), doxorubicin (ADM), paclitaxel (PTX), mitomycin (MMC), 7-Ethyl-10-hydroxycamptothecin (SN-38; the active metabolite of camptothecin) and 5-fluorouracil (5-FU). Merm1/Wbscr22 knockdown cell lines (H1299-shRNA and H460-shRNA) and negative control cell lines (H1299-NC and H460-NC) were established by stable transfection, and the efficiency of Merm1/Wbscr22 knockdown was confirmed by western blotting, immunofluorescence microscopy and quantitative polymerase chain reaction. The results demonstrated that shRNA-mediated knockdown of Merm1/Wbscr22 did not affect cell proliferation in vitro and in vivo. The H460 cells harboring wild type p53 were markedly more sensitive to all six antitumor agents as compared with the p53-null H1299 cells. Downregulation of Merm1/Wbscr22 did not affect H1299 sensitivity to any of the six antitumor agents, whereas attenuated H460 sensitivity to SN-38 and 5-FU, without significant alteration in p53 at both mRNA and protein levels, was identified. The reduced H460 sensitivity to SN-38 was further confirmed in vivo. SN-38 demonstrated significant tumor growth inhibitory activity in both H460 and H460‑NC tumor xenograft models, but only marginally suppressed the H460-shRNA xenograft tumor growth. Furthermore, CDDP (4, 10, 15 µg/ml)-resistant human non-small lung cancer cells A549 (A549-CDDPr-4, 10, 15) expressed significant amounts of Merm1/Wbscr22 protein, as compared with the parental A549 cells. In conclusion, shRNA-mediated knockdown of Merm1/Wbscr22 attenuates H460 sensitivity to SN-38 and 5-FU, suggesting Merm1/Wbscr22 is involved in chemosensitivity to SN-38 and 5-FU in H460 cells. No direct correlation between the p53 expression level and altered chemosensitivity was identified.

Multiparametric monitoring of early response to antiangiogenic therapy: a sequential perfusion CT and PET/CT study in a rabbit VX2 tumor model

OBJECTIVES

To perform dual analysis of tumor perfusion and glucose metabolism using perfusion CT and FDG-PET/CT for the purpose of monitoring the early response to bevacizumab therapy in rabbit VX2 tumor models and to assess added value of FDG-PET to perfusion CT.

METHODS

Twenty-four VX2 carcinoma tumors implanted in bilateral back muscles of 12 rabbits were evaluated. Serial concurrent perfusion CT and FDG-PET/CT were performed before and 3, 7, and 14 days after bevacizumab therapy (treatment group) or saline infusion (control group). Perfusion CT was analyzed to calculate blood flow (BF), blood volume (BV), and permeability surface area product (PS); FDG-PET was analyzed to calculate SUVmax, SUVmean, total lesion glycolysis (TLG), entropy, and homogeneity. The flow-metabolic ratio (FMR) was also calculated and immunohistochemical analysis of microvessel density (MVD) was performed.

RESULTS

On day 14, BF and BV in the treatment group were significantly lower than in the control group. There were no significant differences in all FDG-PET-derived parameters between both groups. In the treatment group, FMR prominently decreased after therapy and was positively correlated with MVD.

CONCLUSIONS

In VX2 tumors, FMR could provide further insight into the early antiangiogenic effect reflecting a mismatch in intratumor blood flow and metabolism.

Accuracy of TNM staging in colorectal cancer: a review of current culprits, the modern role of morphology and stepping-stones for improvements in the molecular era

Colorectal cancer (CRC) is the third most common cancer worldwide. Survival is largely stage-dependant, guided by the tumor-node-metastases (TNM) system for TNM assessment. Histopathological evaluation, including assessment of lymph node status, is important for correct TNM staging. However, recent updates in the TNM system have resulted in controversy. A continued debate on definitions resulting in potential up- and downstaging of patients, which may obscure survival data, has led the investigators to investigate other or alternative staging tools. Consequently, additional prognostic factors have been searched for using the regular light microscopy. Among the factors evaluated by histopathology include the evaluation of tumor budding and stromal environment, angiogenesis, as well as involvement of the immune system (including the 'Immunoscore'). We review the current role of histopathology, controversies in TNM-staging and suggested alternatives to better predict outcome for CRC patients in the era of genomic medicine.

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

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

Morphometric evaluation of vascularization of hepatic focal nodular hyperplasia

Comparative morphometric evaluation of the quantitative characteristics of vessels in hepatic focal nodular hyperplasia tissue was carried out on preparations stained with hematoxylin and eosin and by immunohistochemical detection of CD34 and CD105. Analysis of histological preparations stained with hematoxylin and eosin allowed the most ample characterization. Immunohistochemical detection of CD34 promoted better visualization of endotheliocytes, but just some sinusoids in the preparations were labeled. Expression of CD105 visualized the active endothelial cells and hence, helped to evaluate neoangiogenesis.

Retinoblastoma binding protein 2 (RBP2) promotes HIF-1α-VEGF-induced angiogenesis of non-small cell lung cancer via the Akt pathway

Background

Pathological angiogenesis plays an essential role in tumor aggressiveness and leads to unfavorable prognosis. The aim of this study is to detect the potential role of Retinoblastoma binding protein 2 (RBP2) in the tumor angiogenesis of non-small cell lung cancer (NSCLC).

Methods

Immunohistochemical staining was used to detect the expression of RBP2, hypoxia-inducible factor-1α (HIF-1α), vascular endothelial growth factor (VEGF) and CD34. Two pairs of siRNA sequences and pcDNA3-HA-RBP2 were used to down-regulate and up-regulate RBP2 expression in H1975 and SK-MES-1 cells. An endothelial cell tube formation assay, VEGF enzyme-linked immunosorbent assay, real-time PCR and western blotting were performed to detect the potential mechanisms mediated by RBP2 in tumor angiogenesis.

Results

Of the 102 stage I NSCLC specimens analyzed, high RBP2 protein expression is closely associated with tumor size (P = 0.030), high HIF-1α expression (P = 0.028), high VEGF expression (P = 0.048), increased tumor angiogenesis (P = 0.033) and poor prognosis (P = 0.037); high MVD was associated with high HIF-1α expression (P = 0.034), high VEGF expression (P = 0.001) and poor prognosis (P = 0.040). Multivariate analysis indicated that RBP2 had an independent influence on the survival of patients with stage I NSCLC (P = 0.044). By modulating the expression of RBP2, our findings suggested that RBP2 protein depletion decreased HUVECs tube formation by down-regulating VEGF in a conditioned medium. RBP2 stimulated the up-regulation of VEGF, which was dependent on HIF-1α, and activated the HIF-1α via phosphatidylinositol 3-kinase (PI3K)/Akt signaling pathway. Moreover, VEGF increased the activation of Akt regulated by RBP2.

Conclusions

The RBP2 protein may stimulate HIF-1α expression via the activation of the PI3K/Akt signaling pathway under normoxia and then stimulate VEGF expression. These findings indicate that RBP2 may play a critical role in tumor angiogenesis and serve as an attractive therapeutic target against tumor aggressiveness for early-stage NSCLC patients.

Improved survival in osteosarcoma patients with atypical low vascularization

BACKGROUND

Osteosarcoma is considered a highly vascularized bone tumor with early metastatic dissemination through intratumoral blood vessels mostly into the lung. Novel targets for therapy such as tumor vascularization are highly warranted since little progress has been achieved in the last 30 years. However, proof of relevance for vascularization as a major prognostic parameter has been hampered by tumor heterogeneity, difficulty in detecting microvessels by immunohistochemistry, and small study cohorts. Most recently, we demonstrated that highly standardized whole-slide imaging could overcome these limitations (Kunz et al., PloS One 9(3):e90727, 2014). In this study, we applied this method to a multicenter cohort of 131 osteosarcoma patients to test osteosarcoma vascularization as a prognostic determinant.

METHODS

Computer-assisted whole-slide analysis, together with enzymatic epitope retrieval, was used for CD31-based microvessel quantification in 131 pretreatment formalin-fixed and paraffin-embedded biopsies from three bone tumor centers. Kaplan-Meier-estimated survival and chemoresponse were determined and multivariate analysis was performed. Conventional hot-spot-based microvessel density (MVD) determination was compared with whole-slide imaging.

RESULTS

We detected high estimated overall (p ≤ 0.008) and relapse-free (p ≤ 0.004) survival in 25 % of osteosarcoma patients with low osteosarcoma vascularization in contrast to other patient groups. Furthermore, all patients with low osteosarcoma vascularization showed a good response to neoadjuvant chemotherapy. Comparison of conventional MVD determination with whole-slide imaging suggests false high quantification or even exclusion of samples with low osteosarcoma vascularization due to difficult CD31 detection in previous studies.

CONCLUSION

Low intratumoral vascularization at the time of diagnosis is a strong predictor for prolonged survival and good response to neoadjuvant chemotherapy in osteosarcoma.

Mechanisms of tumour vascularization in cutaneous malignant melanoma: clinical implications

Malignant melanoma represents < 10% of all skin cancers but is responsible for the majority of skin-cancer-related deaths. Metastatic melanoma has historically been considered as one of the most therapeutically challenging malignancies. Fortunately, for the first time after decades of basic research and clinical investigation, new drugs have produced major clinical responses. Angiogenesis has been considered an important target for cancer treatment. Initial efforts have focused primarily on targeting endothelial and tumour-related vascular endothelial growth factor signalling. Here, we review different mechanisms of tumour vascularization described in melanoma and discuss the potential clinical implications.

Angiopoietin-like 4 stimulates STAT3-mediated iNOS expression and enhances angiogenesis to accelerate wound healing in diabetic mice

Impaired wound healing is a major source of morbidity in diabetic patients. Poor outcome has, in part, been related to increased inflammation, poor angiogenesis, and deficiencies in extracellular matrix components. Despite the enormous impact of these chronic wounds, effective therapies are lacking. Here, we showed that the topical application of recombinant matricellular protein angiopoietin-like 4 (ANGPTL4) accelerated wound reepithelialization in diabetic mice, in part, by improving angiogenesis. ANGPTL4 expression is markedly elevated upon normal wound injury. In contrast, ANGPTL4 expression remains low throughout the healing period in diabetic wounds. Exogenous ANGPTL4 modulated several regulatory networks involved in cell migration, angiogenesis, and inflammation, as evidenced by an altered gene expression signature. ANGPTL4 influenced the expression profile of endothelial-specific CD31 in diabetic wounds, returning its profile to that observed in wild-type wounds. We showed ANGPTL4-induced nitric oxide production through an integrin/JAK/STAT3-mediated upregulation of inducible nitric oxide synthase (iNOS) expression in wound epithelia, thus revealing a hitherto unknown mechanism by which ANGPTL4 regulated angiogenesis via keratinocyte-to-endothelial-cell communication. These data show that the replacement of ANGPTL4 may be an effective adjunctive or new therapeutic avenue for treating poor healing wounds. The present finding also confirms that therapeutic angiogenesis remains an attractive treatment modality for diabetic wound healing.

Lymphangiogenesis: implications for diagnosis, treatment, and prognosis in patients with melanoma

Disease course in melanoma often cannot be accurately predicted by means of the prognostic factors usually considered in patients with melanoma; therefore, new factors are clearly needed. Increasingly robust scientific evidence shows that tumor lymph vessels play a key role in melanoma that metastasizes by lymphatic and hematogenous pathways. We review current knowledge and examine the implications of lymphangiogenesis in the diagnosis, treatment, and prognosis of patients with melanoma.

Assessment of tumor grade and angiogenesis in colorectal cancer: whole-volume perfusion CT

RATIONALE AND OBJECTIVES

The preoperative evaluation of tumor grading and angiogenesis has important clinical implications in the treatment and prognosis of patients with colorectal cancers (CRCs). The aim of the present study was to assess tumor perfusion with 256-slice computed tomography (CT) using whole-volume perfusion technology before surgery, and to investigate the differences in the perfusion parameters among tumor grades and the correlation between perfusion parameters and pathologic results in CRC.

MATERIALS AND METHODS

Thirty-seven patients with CRC confirmed by endoscopic pathology underwent whole-volume perfusion CT assessments with a 256-slice CT and surgery. Quantitative values for blood flow, blood volume, and time to peak were determined using commercial software. After surgery, resected specimens were analyzed immunohistochemically with CD105 antibodies for the quantification of microvessel density (MVD). The difference in CT perfusion parameters and MVD among different tumor differentiation grades was evaluated by the Student-Newman-Keuls test. The correlations between CT perfusion parameters and MVD were evaluated using the Pearson correlation analysis.

RESULTS

The mean blood flow was significantly different among well, moderately, and poorly differentiated groups (61.17 ± 17.97, 34.80 ± 13.06, and 22.24 ± 9.31 mL/minute/100 g, respectively; P < .05). The blood volume in the well-differentiated group was significantly higher than that in the moderately differentiated group (33.96 ± 24.81 vs. 16.93 ± 5.73 mL/100 g; P = .002) and that in the poorly differentiated group (33.96 ± 24.81 vs. 18.05 ± 6.01 mL/100 g; P = .009). The time to peak in the poorly differentiated group was significantly longer than that in the well-differentiated group (27.81 ± 11.95 vs. 17.60 ± 8.53 seconds; P = .016) and that in the moderately differentiated group (27.81 ± 11.95 vs. 18.94 ± 7.47 seconds; P = .028). There was no significant difference in the MVD among well, moderately, and poorly differentiated groups (33.47 ± 14.69, 28.89 ± 11.82, and 29.89 ± 11.02, respectively; P > .05). There was no significant correlation between CT perfusion parameters and MVD (r = 0.201, 0.295, and -0.178, respectively; P = .233, .076, and .292, respectively).

CONCLUSIONS

CT whole-volume perfusion technology has the potential to evaluate pathologic differentiation grade of CRC before surgery. However, preoperative perfusion CT parameters do not reflect the MVD of CRC.

Pancreatic tumor cell secreted CCN1/Cyr61 promotes endothelial cell migration and aberrant neovascularization

The complex signaling networks between cancer cells and adjacent endothelial cells make it challenging to unravel how cancer cells send extracellular messages to promote aberrant vascularization or tumor angiogenesis. Here, in vitro and in vivo models show that pancreatic cancer cell generated unique microenvironments can underlie endothelial cell migration and tumor angiogenesis. Mechanistically, we find that pancreatic cancer cell secreted CCN1/Cyr61 matricellular protein rewires the microenvironment to promote endothelial cell migration and tumor angiogenesis. This event can be overcome by Sonic Hedgehog (SHh) antibody treatment. Collectively, these studies identify a novel CCN1 signaling program in pancreatic cancer cells which activates SHh through autocrine-paracrine circuits to promote endothelial cell migration and tumor angiogenesis and suggests that CCN1 signaling of pancreatic cancer cells is vital for the regulation of tumor angiogenesis. Thus CCN1 signaling could be an ideal target for tumor vascular disruption in pancreatic cancer.

Overexpression of LAPTM4B is correlated with tumor angiogenesis and poor prognosis in non-small cell lung cancer

Lysosome-associated protein transmembrane-4 beta (LAPTM4B) is a novel oncogene, which has been indicated to be dramatically overexpressed in various malignant tumors. The aims of this study were to detect LAPTM4B protein expression in patients with non-small cell lung cancer (NSCLC) and then analyze the relationships of LAPTM4B protein with clinicopathologic factors, tumor angiogenesis and prognosis with SPSS statistical software. Immunohistochemistry was used to examine the expression of LAPTM4B and CD34 proteins in NSCLC tissues, and its results showed that LAPTM4B protein expression in NSCLC tissues was significantly higher than that in normal lung tissues (P < 0.001). Of the186 NSCLC cases, 129 (69.35 %) had strong expression of LAPTM4B protein, which was associated with histopathologic differentiation (P = 0.017), lymph node metastasis (P = 0.001) and TNM stage (P = 0.046), as well as the microvessel density (MVD) (P = 0.019). Kaplan-Meier survival analysis revealed that patients with strong LAPM4B protein expression and high MVD might have poor overall survival (OS; P = 0.001, P = 0.002, respectively) and disease-free survival (DFS; P = 0.002, P = 0.038, respectively). Multivariate analysis demonstrated that LAPTM4B protein was an independent prognostic marker for OS and DFS of NSCLC patients (P = 0.037, P = 0.046, respectively). These findings illustrated that LAPTM4B protein was closely associated with NSCLC progression, angiogenesis and poor prognosis, suggesting that LAPTM4B protein could be applied not only in predicting patient's outcome, but also in antiangiogenic therapy as a possible novel target molecule.

Squamous cell carcinomas of the skin explore angiogenesis-independent mechanisms of tumour vascularization

Aims. To evaluate the vascularization in basal cell carcinomas (BCCs) and squamous cell carcinomas (SCCs) of the skin. Methods. We performed CD31 (i.e., panendothelial marker) and CD105 (i.e., proliferating endothelium marker) immunostaining on samples of 70 SCCs and 70 BCCs of the skin. We evaluated the relative blood vessel area using the Chalkley counting method in each histologic subtype of these tumours. We calculated the degree of proliferation of blood vessel endothelium dividing CD105-Chalkley score by CD31-Chalkley score. Results. We found significantly higher peritumoral and intratumoral blood vessel area in SCC when compared to BCC (both with CD31 and CD105). Chalkley counts differed significantly between groups with different BCC histologic subtypes and SCC with different grade of differentiation. Surprisingly, the degree of proliferation of blood vessel endothelium was higher in BCC when compared to SCC. Conclusions. While SCC exhibited significantly higher intratumoral and peritumoral blood vessel areas compared to BCC, the relatively low rate of proliferating endothelium in this tumour type suggests the existence of endothelial-sprouting-independent mechanisms of vascularization in SCC.

Role of VEGF-A and its receptors in sporadic and MEN2-associated pheochromocytoma

Pheochromocytoma (PHEO), a rare catecholamine producing tumor arising from the chromaffin cells, may occurs sporadically (76%–80%) or as part of inherited syndromes (20%–24%). Angiogenesis is a fundamental step in tumor proliferation and vascular endothelial growth factor (VEGF-A) is the most well-characterized angiogenic factor. The role of angiogenic markers in PHEO is not fully understood; investigations were therefore made to evaluate the expression of VEGF-A and its receptors in PHEO and correlate to clinical parameters. Twenty-nine samples of PHEO were evaluated for VEGF-A, VEGF receptor-1 (VEGFR-1) VEGFR-2 expression and microvessel density (MVD) by immunohistochemistry. Clinical data were reviewed in medical records. The mean age of patients was 38 ± 14 years, and 69% were woman. VEGF-A, VEGFR-1 and VEGFR-2 staining were detected in nearly all PHEO samples. No significant correlation was observed between VEGF-A, VEGFR-1, VEGFR-2 expression or MVD and age at diagnosis, tumor size or sporadic and hereditary PHEO. However, the levels of expression of these molecules were significantly higher in malignant PHEO samples (p = 0.027, p = 0.003 and p = 0.026, respectively).VEGF-A and its receptors were shown to be up-regulated in malignant PHEO, suggesting that these molecules might be considered as therapeutic targets for unresectable or metastatic tumors.

Distribution of podoplanin-positive tumor vessels predicts disease-specific survival of node-positive breast cancer patients treated with anthracyclines and/or taxanes

We analyzed survival of 102 invasive ductal, node positive breast cancer patients, treated with surgery and adjuvant chemotherapy (anthracyclines and/or taxanes) with relation to: (a) well-known clinicopathological parameters, (b) MIB-1 labeling index (LI), (c) the distribution of podoplanin-positive vessels (DPV), expression of: (d) basal markers, and (e) fascin. Lower progression risk was found for patients with tumors characterized by (i) pN1 + pN2, (ii) MIB-1LI ≤ 28%, (iii) lack of lymphatic vessels or high tumor DPV than for patients with pN3, MIB-1LI > 28%, low DPV, respectively. Cox multivariate analysis revealed that both pN3 and low DPV were negative prognostic indicators.

Osteosarcoma microenvironment: whole-slide imaging and optimized antigen detection overcome major limitations in immunohistochemical quantification

BACKGROUND

In osteosarcoma survival rates could not be improved over the last 30 years. Novel biomarkers are warranted to allow risk stratification of patients for more individual treatment following initial diagnosis. Although previous studies of the tumor microenvironment have identified promising candidates, novel biomarkers have not been translated into routine histopathology. Substantial difficulties regarding immunohistochemical detection and quantification of antigens in decalcified and heterogeneous osteosarcoma might largely explain this translational short-coming. Furthermore, we hypothesized that conventional hot spot analysis is often not representative for the whole section when applied to heterogeneous tissues like osteosarcoma. We aimed to overcome these difficulties for major biomarkers of the immunovascular microenvironment.

METHODS

Immunohistochemistry was systematically optimized for cell surface (CD31, CD8) and intracellular antigens (FOXP3) including evaluation of 200 different antigen retrieval conditions. Distribution patterns of these antigens were analyzed in formalin-fixed and paraffin-embedded samples from 120 high-grade central osteosarcoma biopsies and computer-assisted whole-slide analysis was compared with conventional quantification methods including hot spot analysis.

RESULTS

More than 96% of osteosarcoma samples were positive for all antigens after optimization of immunohistochemistry. In contrast, standard immunohistochemistry retrieved false negative results in 35-65% of decalcified osteosarcoma specimens. Standard hot spot analysis was applicable for homogeneous distributed FOXP3+ and CD8+ cells. However, heterogeneous distribution of vascular CD31 did not allow reliable quantification with hot spot analysis in 85% of all samples. Computer-assisted whole-slide analysis of total CD31- immunoreactive area proved as the most appropriate quantification method.

CONCLUSION

Standard staining and quantification procedures are not applicable in decalcified formalin-fixed and paraffin-embedded samples for major parameters of the immunovascular microenvironment in osteosarcoma. Whole-slide imaging and optimized antigen retrieval overcome these limitations.

TFIIB-related factor 2 over expression is a prognosis marker for early-stage non-small cell lung cancer correlated with tumor angiogenesis

Background

The aim of this study was to examine BRF2 expression in patients with non-small cell lung cancer (NSCLC) and explore the relationship of BRF2 protein with clinicopathologic factors, tumor angiogenesis and prognosis.

Methods

Both BRF2 protein and intratumoral microvessels were examined by immunohistochemical staining in 107 non-small cell lung cancer patients. Intratumoral m icrovessel density (MVD) was measured by counting CD-34 positive immunostained endothelial cells. Western blot and RT-PCR analyses were utilized to investigate the BRF2 expression status in tissues

Results

A notably higher level of BRF2 expression was found in NSCLC tissues at protein levels. In addition, univariate and multivariate analysis demonstrated that BRF2 protein over-expression and high MVD were significantly associated with tumor relapse. Although BRF2 overexpression and high MVD indicated poor 5-year overall survival (p = 0.004 and p = 0.019, respectively), multivariate analysis demonstrated that only BRF2 overexpression was an independent prognostic factor for unfavorable overall survival (P = 0.021).

Conclusions

BRF2 is a promising biomarker to identify individuals with poor prognostic potential and a possible target for anti-angiogenic therapy for patients with early-stage NSCLC.

Study of microvessel density and the expression of vascular endothelial growth factors in adrenal gland pheochromocytomas

Angiogenesis (neoangiogenesis), a process of neovascularization, is an essential step for local tumor growth and distant metastasis formation. We have analysed angiogenesis status: vascular architecture, microvessel density, and vascular endothelial growth factors expression in 62 adrenal pheochromocytomas: 57 benign and 5 malignant. Immunohistochemical evaluation revealed that vascular architecture and vessel density are different in the central and subcapsular areas of the tumor. Furthermore, we have observed a strong correlation between number of macrophages and microvessel density in the central and subcapsular areas of the tumor and between the expression of VEGF-A in tumor cells and microvessel density in central and subcapsular areas of the tumor. Secondary changes in these tumors influence the results and both vascular architecture and microvessel density are markedly disturbed by hemorrhagic and cystic changes in pheochromocytomas. These changes are partially caused by laparoscopic operation technique. However, no differences in vascular parameters were found between pheochromocytomas with benign and malignant clinical behavior. Our observation showed that analysis of angiogenesis, as a single feature, does not help in differentiating malignant and benign pheochromocytomas and has no independent prognostic significance. On the other hand, high microvessel density in pheochromocytoma is a promising factor for antiangiogenic therapy in malignant cases.

Chalkley method in the angiogenesis research and its automation via computer simulation

The aim of this study was to develop a computer simulation evaluating microvessel density according to the Chalkley method on digital images taken from neovascular hot spots. An image analysis algorithm has been developed using ImageJ, an extensible, open source image processing and analysis software. The idea was to create a virtual Chalkley point array graticule, and to calculate Chalkley counts automatically by stepwise angular rotation of it on the superimposed images containing properly segmented microvessels. This eliminates the necessity of having the Chalkley graticule, an accessory that has to be mounted on the microscope's ocular. The proposed method is a faithful simulation of the original Chalkley counting procedure. It gives pathologists who do not have the Chalkley graticule an opportunity to evaluate microvessels quantitatively according to the basic principles underlying Chalkley counting. Evaluating microvessel densities in solid tumors is a frequent procedure in angiogenesis research. A few standard methods, including Chalkley counting, are used for the estimation of microvessel density. Several independent studies have shown that the Chalkley counting is more consistent and may provide useful data on prognosis. The obvious disadvantages lie in the facts that this method is time-consuming and requires a special hardware. Computer simulation may overcome these obstacles.

Angiogenesis in canine mammary tumours: a morphometric and prognostic study

Angiogenesis in canine mammary tumours (CMTs) has been described previously; however, only the intratumoural (IT) region has been studied and information on peritumoural (PT) angiogenesis is lacking. In this study, the blood vessel density (BVD), blood vessel perimeter (BVP) and blood vessel area (BVA) in IT and PT regions of 56 benign CMTs, 55 malignant CMTs and 13 samples of normal mammary gland tissue were analyzed. In addition, the blood endothelial cell proliferation (BECP) as an indicator of ongoing angiogenesis was investigated. The prognostic value of each parameter was also examined. Blood vessels and proliferating blood endothelial cells were present in IT and PT regions of both benign and malignant tumours. The vessels in the PT region had a significantly higher area and perimeter compared with those in the IT region. Malignant tumours showed significantly more vessels with a smaller total BVA and a higher BECP compared with benign tumours and control tissue. In the PT regions there was a significantly higher BVD, BVA and BVP compared with the vessels in control tissue. Only the IT and PT BVD and PT BECP in benign tumours allowed prediction of survival. The morphology of blood vessels in CMTs shows similarities with those in human breast cancer, which strengthens the case for the use of dogs with CMTs in comparative oncology trials.

Primary tumor vascularity, HIF-1α and VEGF expression in vulvar squamous cell carcinomas: their relationships with clinicopathological characteristics and prognostic impact

BACKGROUND

Increased vascularity is a crucial event in the tumor progression and has prognostic significance in various cancers. However, the ultimate role of angiogenesis in the pathogenesis and clinical outcome of vulvar carcinoma patients is still not settled.

METHODS

Tumor vascularity using CD34 stained slides measured by Chalkley counting method as well as hypoxia-inducible factor (HIF)-1α and vascular endothelial growth factor (VEGF) immunoexpression was examined in 158 vulvar squamous cell carcinomas. Associations between vascular Chalkley count, HIF-1α and VEGF expression and clinicopathological factors and clinical outcome were evaluated.

RESULTS

High CD34 Chalkley count was found to correlate with larger tumor diameter (P = 0.002), deep invasion (P < 0.001) and HIF-1α (P = 0.04), whereas high VEGF expression correlate significantly with poor tumor differentiation (P = 0.007). No significant association between CD34 Chalkley counts and VEGF expression and disease-specific survival was observed. High HIF-1α expression showed better disease specific survival in both univariate and multivariate analyses (P = 0.001).

CONCLUSIONS

A significant association between high tumor vascularity and larger tumor size as well as deeper tumor invasion suggests an important role of angiogenesis in the growth and progression of vulvar carcinomas. HIF-1α expression in vulvar carcinomas was a statistically independent prognostic factor.

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

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

Impact of SOX18 expression in cancer cells and vessels on the outcome of invasive ductal breast carcinoma

PURPOSE

SOX18 is a transcription factor known to be involved in hair follicle, blood and lymphatic vessel development, as well as wound healing processes (together with SOX7 and SOX17). In addition, it has been reported that SOX18 may affect the growth of cancer cells in vitro. Until now, the exact role of SOX18 expression in invasive ductal breast carcinoma (IDC) has remained unknown.

METHODS

In this study, we have investigated SOX18 expression in cancer cells and endothelial cells in 122 IDC samples using immunohistochemistry (IHC). SOX18 expression was also determined using real-time PCR and Western blotting in a series of breast cancer-derived cell lines (i.e., MCF-7, BT-474, SK-BR-3, MDA-MB-231, BO2).

RESULTS

Using IHC, we observed SOX18 nuclear expression in cancer cells, as well as in blood and lymphatic vessels of the IDC samples tested. SOX18 expression in the IDC samples correlated with a higher malignancy grade (Grade 2 and Grade 3 versus Grade 1; p = 0.02 and p = 0.009, respectively) and VEGF-D expression (r = 0.27, p = 0.007). SOX18 expression was also associated with HER2 positivity (p = 0.02). A significantly higher SOX18 expression was found in the HER2-positive cell line BT-474, and a significantly lower expression in the triple negative cell lines MDA-MB-231 and BO2. Laser capture microdissection of IDC samples revealed significantly higher mRNA SOX7, SOX17 and SOX18 expression levels in the vessels as compared to the cancer cells (p = 0.02 and p = 0.0002, p < 0.0001, respectively). SOX18 positive intratumoral and peritumoral microvessel counts (MVC) were associated with higher malignancy grades (p = 0.04 and p = 0.02, respectively). Moreover, peritumoral SOX18 positive MVC were found to act as an independent marker for a poor prognosis (p = 0.04).

CONCLUSION

SOX18 expression may serve as a marker for a poor prognosis in IDC.

Inducible nitric oxide synthase expression in gastric adenocarcinoma: impact on lymphangiogenesis and lymphatic metastasis

Background

Lymphatic metastasis is the most important parameter in the spread of gastric carcinomas. Nitric oxide (NO) is a signaling molecule that plays an important role in inflammation and carcinogenesis. In this study, the possible link between inducible nitric oxide synthase (iNOS) expression with lymphangiogenesis and the clinicopathological parameters of gastric carcinomas was investigated.

Methods

In this study, iNOS expression and D2-40 (lymphatic endothelium-specific marker monoclonal antibody) reactivity were examined immunohistochemically in 41 gastric adenocarcinoma and 20 non-neoplastic gastric tissues. iNOS expression was scored semiquantitatively in the tumor parenchyma and stroma. D2-40-positive lymphatic vessels were used in the determination of lymphatic invasion and intratumoral and peritumoral lymphatic vascular density.

Results

iNOS expression was higher in gastric carcinoma tissue compared with non-neoplastic tissue. Particularly, iNOS expression in tumor cells was found to be closely related to lymphangiogenesis and lymphatic metastasis. The density of lymphatic invasion as well as intratumoral and peritumoral lymphatic vascular density were positively correlated with lymph node metastasis.

Conclusions

Our results suggest that iNOS-mediated NO formation plays an important role in gastric carcinogenesis, tumor lymphangiogenesis, and the development of lymphatic metastases. Inhibition of the NO pathway may be an alternative treatment of gastric carcinomas.

Virtual slides

The virtual slides for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/1713572940104388.

Is lymphatic endoglin expression a risk marker for breast cancer metastasis? Results of a pilot study

BACKGROUND

Studies have identified endoglin as a biological marker that is overexpressed on the microvessels of certain solid cancers (breast, colorectal cancer, and head and neck squamous cell cancers). There is, at present, no immunohistochemical marker that can discriminate between lymph node-negative and or lymph node-positive breast cancer tissue.

METHODS

The expression of endoglin was quantified by immunohistochemistry and assessment of microvessel density in 53 surgical specimens. These were comprised of breast tumor tissue that had not spread to the regional lymph nodes (lymph node-negative breast tumor tissue: 20 specimens), breast tumor tissue had spread to regional lymph nodes (lymph node-positive breast tumor tissue: 21 specimens), and normal breast tissue as a control (12 specimens).

RESULTS

Significant difference was observed between the expression of endoglin on microvessels of lymph node-negative and lymph node-positive breast cancer tissue (p<0.05). This significant difference was shown to be due to endoglin expression on lymphatic vessels (p<0.02), rather than on blood vessels (p>0.05).

CONCLUSIONS

These findings are the first to suggest that endoglin expression on breast tumor lymphatic vessels may have diagnostic potential as a discriminator between lymph node-negative and lymph node-positive breast cancer. Further studies would be required to confirm this.

Digital microscopy assessment of angiogenesis in different breast cancer compartments

Background/Aim. Tumour angiogenesis defined by microvessel density (MVD) is generally accepted as a prognostic factor in breast cancer. However, due to variability of measurement systems and cutoffs, it is questionable to date whether it contributes to predictive outline. Our study aims to grade vascular heterogeneity by comparing clear-cut compartments: tumour associated stroma (TAS), tumour parenchyma, and tumour invasive front. Material and Methods. Computerized vessel area measurement was performed using a tissue cytometry system (TissueFAXS) on slides originated from 50 patients with breast cancer. Vessels were marked using immunohistochemistry with CD34. Regions of interest were manually defined for each tumour compartment. Results. Tumour invasive front vascular endothelia area was 2.15 times higher than that in tumour parenchyma and 4.61 times higher than that in TAS (P < 0.002). Worth to mention that the lymph node negative subgroup of patients show a slight but constant increase of vessel index in all examined compartments of breast tumour. Conclusion. Whole slide digital examination and region of interest (ROI) analysis are a valuable tool in scoring angiogenesis markers and disclosing their prognostic capacity. Our study reveals compartments' variability of vessel density inside the tumour and highlights the propensity of invasive front to associate an active process of angiogenesis with potential implications in adjuvant therapy.

Krüppel-like factor 8 overexpression is correlated with angiogenesis and poor prognosis in gastric cancer

AIM: To investigate Krüppel-like factor 8 (KLF8) expression in gastric cancer and its relationship with angiogenesis and prognosis of gastric cancer.

METHODS: One hundred and fifty-four patients with gastric cancer who underwent successful curative resection were retrospectively enrolled in the study. Fifty tumor-adjacent healthy gastric tissues (≥ 5 cm from the tumor margin) obtained during the original resection were randomly selected for comparative analysis. In situ expression of KLF8 and CD34 proteins were examined by immunohistochemistry. The intratumoral microvessel density (MVD) was determined by manually counting the immunostained CD34-positive endothelial cells in three consecutive high-magnification fields (× 200). The relationship between differential KLF8 expression and MVD was assessed using Spearman’s correlation coefficient test. χ² test was performed to evaluate the effects of differential KLF8 expression on clinicopathologic factors. Kaplan-Meier and multivariate Cox survival analyses were used to assess the prognostic value of differential KLF8 expression in gastric cancer.

RESULTS: Significantly higher levels of KLF8 protein were detected in gastric cancer tissues than in the adjacent non-cancerous tissues (54.5% vs 34.0%, P < 0.05). KLF8 expression was associated with tumor size (P < 0.001), local invasion (P = 0.005), regional lymph node metastasis (P = 0.029), distant metastasis (P = 0.023), and tumor node metastasis (TNM) stage (P = 0.002), as well as the MVD (r = 0.392, P < 0.001). Patients with KLF8 positive expression had poorer overall survival (P < 0.001) and cancer-specific survival (P < 0.001) than those with negative expression. Multivariate analysis demonstrated that KLF8 expression independently affected both overall and cancer-specific survival of gastric cancer patients (P = 0.035 and 0.042, respectively).

CONCLUSION: KLF8 is closely associated with gastric tumor progression, angiogenesis and poor prognosis, suggesting it may represent a novel prognostic biomarker and therapeutic target for gastric cancer.

The radiosensitizing effect of CpG ODN107 on human glioma cells is tightly related to its antiangiogenic activity via suppression of HIF-1α/VEGF pathway

Malignant glioma displays invasive growth and is difficult to be completely excised; surgery combined with subsequent radiotherapy is a standard treatment for patients. CpG oligodeoxynucleotides (CpG ODN) can enhance radiotherapeutic effect in some tumors. Angiogenesis is crucial for tumor progression and metastasis. Anti-angiogenic strategy thus may be effective for tumor treatment. Herein, the antiangiogenic activity and radiosensitizing effect of CpG ODN107 on glioma were investigated. Our results showed that the growth of glioma cell line U87 was significantly inhibited by CpG ODN107 (10μg/ml) in combination with irradiation (5Gy) in vitro. In orthotopic implantation model of nude mice, the survival rate of mice significantly increased after treatment with CpG ODN107 (0.083mg/kg) in combination with radiotherapy (10Gy) as compared with treatment with local radiotherapy alone. CpG ODN107 in combination with radiotherapy significantly decreased microvessel density (MVD), VEGF level and HIF-1α expression in orthotopic implantation glioma. In conclusion, CpG ODN107 significantly increased the radiosensitivity of U87 human glioma cells in vitro and in vivo. The radiosensitizing effect of CpG ODN 107 is tightly related to its anti-angiogenic activity via suppression of HIF-1α/VEGF pathway.

Expression of EGFR, VEGF, and NOTCH1 suggest differences in tumor angiogenesis in HPV-positive and HPV-negative head and neck squamous cell carcinoma

There is current interest in anti-angiogenesis therapies for head and neck squamous cell carcinomas (HNSCC), although the utility of these therapies in human papillomavirus (HPV) positive and HPV-negative HNSCC is unclear. Therefore, we explored heterogeneity in expression of a distal factor in angiogenesis (EGFR, the epidermal growth factor receptor), a proximal factor in angiogenesis (VEGF, the vascular endothelial growth factor) and a putative factor in angiogenesis (NOTCH1) in a HNSCC case series using immunohistochemistry in N = 67 cases (27 HPV-positive, 40 HPV-negative, by in situ hybridization). Box plots and the Wilcoxon rank sum or Kruskal-Wallis tests were used to compare staining scores (intensity × percent of cells staining) by HPV status and lifestyle factors. Associations between EGFR, VEGF, and NOTCH1 were assessed using box plots and Spearman correlation (ρ) in all cases, and stratified by HPV status. HPV-negative HNSCC over-expressed EGFR [median (range): 30 (0-300)] relative to HPV-positive HNSCC [7.5 (0-200)] (P = 0.006). VEGF and NOTCH1 were unrelated to HPV status (P > 0.05). EGFR was associated with VEGF in HPV-negative (ρ = 0.40, P = 0.01) but not HPV-positive HNSCC (ρ = 0.25, P = 0.20). NOTCH1 and VEGF were associated in HPV-negative (ρ = 0.40, P = 0.01) but not HPV-positive tumors (ρ = -0.12, P = 0.57). NOTCH1 was not associated with EGFR (P > 0.05). Our results are suggestive of heterogeneity in HNSCC angiogenesis. Future studies should explore angiogenesis mechanisms in HPV-positive and HPV-negative HNSCC.

Multifactorial diagnostic NIR imaging of CCK2R expressing tumors

Optical imaging-based diagnostics identify malignancies based on molecular changes instead of morphological criteria in a non-invasive, irradiation free process. The aim of this study was to improve imaging efficiency by the development of a new Cholecystokinin-2-receptor targeted fluorescent peptide that matches the clinical needs regarding biodistribution and pharmacokinetics while displaying superior target specificity. Furthermore we performed multifactorial imaging of Cholecystokinin-2-receptor and tumor metabolism, since simultaneous targeting of various tumor biomarkers could intensely increase tumor identification and characterization. Affinity and specificity of the fluorescent Cholecystokinin-2-receptor targeted minigastrin (dQ-MG-754) were tested in vitro. We conducted in vivo imaging of the dQ-MG-754 probe alone and in a multifactorial approach with a GLUT-1 targeted probe (IR800 2-DG) on subcutaneous xenograft bearing athymic nude mice up to 24 h after intravenous injection (n = 5/group), followed by ex vivo biodistribution analysis and histological examination. We found specific, high affinity binding (Kd = 1.77 nM ± 0.6 nM) of dQ-MG-754 to Cholecystokinin-2-receptor expressing cells and xenografts as well as favorable pharmacokinetics for fluorescence-guided endoscopy. We successfully performed multifactorial imaging for the simultaneous detection of the Cholecystokinin-2-receptor and GLUT-1 targeted probe. Prominent differences in uptake patterns of the two contrast agents could be detected. The results were validated by histological examinations. The multifactorial imaging approach presented in this study could facilitate cancer detection in diagnostic imaging and intraoperative and endoscopic applications. Especially the dQ-MG-754 probe bears great potential for translation to clinical endoscopy imaging, because it combines specific high affinity binding with renal elimination and a favorable biodistribution.

Tumor angiogenesis phenotyping by nanoparticle-facilitated magnetic resonance and near-infrared fluorescence molecular imaging

One of the challenges of tailored antiangiogenic therapy is the ability to adequately monitor the angiogenic activity of a malignancy in response to treatment. The α(v)β(3) integrin, highly overexpressed on newly formed tumor vessels, has been successfully used as a target for Arg-Gly-Asp (RGD)-functionalized nanoparticle contrast agents. In the present study, an RGD-functionalized nanocarrier was used to image ongoing angiogenesis in two different xenograft tumor models with varying intensities of angiogenesis (LS174T > EW7). To that end, iron oxide nanocrystals were included in the core of the nanoparticles to provide contrast for T(2)*-weighted magnetic resonance imaging (MRI), whereas the fluorophore Cy7 was attached to the surface to enable near-infrared fluorescence (NIRF) imaging. The mouse tumor models were used to test the potential of the nanoparticle probe in combination with dual modality imaging for in vivo detection of tumor angiogenesis. Pre-contrast and post-contrast images (4 hours) were acquired at a 9.4-T MRI system and revealed significant differences in the nanoparticle accumulation patterns between the two tumor models. In the case of the highly vascularized LS174T tumors, the accumulation was more confined to the periphery of the tumors, where angiogenesis is predominantly occurring. NIRF imaging revealed significant differences in accumulation kinetics between the models. In conclusion, this technology can serve as an in vivo biomarker for antiangiogenesis treatment and angiogenesis phenotyping.

Mounting a strategic offense: fighting tumor vasculature with oncolytic viruses

Blood supply within a tumor drives progression and ultimately allows for metastasis. Many anticancer therapies target tumor vasculature, but their individual effectiveness is limited because they induce indirect cell death. Agents that disrupt nascent and/or established tumor vasculature while simultaneously killing cancer cells would certainly have a greater impact. Oncolytic virotherapy utilizes attenuated viruses that replicate specifically within a tumor. They induce cytotoxicity through a combination of direct cell lysis, antitumor immune stimulation, and recently identified antitumor vascular effects. This review summarizes the novel preclinical and clinical evidence regarding the antitumor vascular effects of oncolytic viruses, which include infection and lysis of tumor endothelial cells, natural or genetically engineered antiangiogenic properties, and combination therapy with clinically approved antivascular agents.

Endoglin (CD105) expression on microvessel endothelial cells in juvenile nasopharyngeal angiofibroma: tissue microarray analysis and association with prognostic significance

BACKGROUND

The purpose of this study was to examine endoglin (CD105) expression on microvessel endothelial cells (ECs) in juvenile nasopharyngeal angiofibroma (JNA) and its relationship with recurrence.

METHODS

Immunohistochemistry was performed to detect CD105 expression in a tissue microarray from 70 patients with JNA. Correlation between CD105 expression on microvessel ECs and clinicopathological features, as well as tumor recurrence, were analyzed.

RESULTS

Immunohistochemistry revealed CD105 expression on ECs but not in stroma of patients with JNA. Chi-square analysis indicated CD105-based microvessel density (MVD) was correlated with JNA recurrence (p = .013). Univariate and multivariate analyses determined that MVD was a significant predictor of time to recurrence (p = .009). The CD105-based MVD was better for predicting disease recurrence (AUROC: 0.673; p = .036) than other clinicopathological features.

CONCLUSIONS

MVD is a useful predictor for poor prognosis of patients with JNA after curative resection. Angiogenesis, which may play an important role in the occurrence and development of JNA, is therefore a potential therapeutic target for JNA.

Down-regulation of heparanase leads to the inhibition of invasion and proliferation of A549 cells in vitro and in vivo

Heparanase is a mammalian endoglycosidase that degrades heparan sulfate at the cell surface and in the extracellular matrix. The expression of heparanase was detected in a wide variety of human malignant tumors and closely associated with tumor invasion, metastasis, and angiogenesis. However, the specific roles of heparanase and its mechanisms of regulating the malignant potential of non-small cell lung cancer (NSCLC) cells still remain unclear. In the present study, the expression of heparanase was down-regulated in NSCLC cell line by antisense oligodeoxynucleotide. Results showed that down-regulation of heparanase led to significant inhibition of invasive and proliferative potentials of A549 cells in vitro and in vivo. Further research demonstrated that down-regulation of heparanase significantly inhibited the angiogenic potential of A549 cells, which might be the mechanism responsible for the inhibition of A549 cell proliferation in BALB/c nude mice in vivo. These findings demonstrate that heparanase plays essential roles in regulating the invasion, proliferation, and angiogenesis of A549 cells.

Angiogenin expression in human kidneys and Wilms' tumours: relationship with hypoxia and angiogenic factors

Angiogenin (ANG) is a potent angiogenic factor that is up-regulated by hypoxia. ANG expression is well documented in normal tissues and in common tumours, but its expression has not been reported in the normal human kidney or in Wilms' tumours (WT). We examined ANG expression in WTs, human fetal kidney (FK) and childhood kidney (NK) samples and studied its relationship with microvascular density (MVD) and with three other hypoxia-induced angiogenic factors: lactate dehydrogenase A (LDHA), vascular endothelial growth factor (VEGFA) and BHLHE40 (basic helix-loop-helix transcription factor E40). Total ANG protein levels were significantly lower in WTs when compared with those in 15 matched-paired NKs. ANG immunoreactivity was observed in the glomeruli, proximal tubules and vessels in the FKs and NKs, indicating that ANG plays a physiological role in the human kidney. ANG cellular localization and distribution in 27 WTs reflected the pattern observed in the FKs. ANG colocalized with LDHA in the perinecrotic areas of untreated WTs suggesting up-regulation by hypoxia. There was a significant correlation between CD31-MVD and ANG-MVD. ANG, CD31, VEGFA and BHLHE40 mRNA levels were significantly lower in 15 WTs compared with matched-paired NKs. Univariable and multivariable statistical analyses showed significant correlations between ANG and CD31, ANG and BHLHE40 mRNAs and a weaker relationship between ANG and VEGFA mRNAs. ANG expression in WTs recapitulates that seen during nephrogenesis, and correlation with CD31-MVDs and mRNAs is consistent with a contribution to angiogenesis in WTs. Our study contributes to the understanding of angiogenesis during development and in WTs.

Correlations of dynamic contrast-enhanced magnetic resonance imaging with morphologic, angiogenic, and molecular prognostic factors in rectal cancer

PURPOSE

To investigate the correlations between parameters of dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) and prognostic factors in rectal cancer.

MATERIALS AND METHODS

We studied 29 patients with rectal cancer who underwent gadolinium contrast-enhanced, T1-weighted DCE-MRI with a three Tesla scanner prior to surgery. Signal intensity on DCE-MRI was independently measured by two observers to examine reproducibility. A time-signal intensity curve was generated, from which four semiquantitative parameters were calculated: steepest slope (SLP), time to peak (Tp), relative enhancement during a rapid rise (Erise), and maximal enhancement (Emax). Morphologic prognostic factors including T stage, N stage, and histologic grade were identified. Tumor angiogenesis was evaluated in terms of microvessel count (MVC) and microvessel area (MVA) by morphometric study. As molecular factors, the mutation status of the K-ras oncogene and microsatellite instability were assessed. DCE-MRI parameters were correlated with each prognostic factor using bivariate correlation analysis. A p-value of <0.05 was considered significant.

RESULTS

Erise was significantly correlated with N stage (r=-0.387 and -0.393, respectively, for two independent data), and Tp was significantly correlated with histologic grade (r=0.466 and 0.489, respectively). MVA was significantly correlated with SLP (r= -0.532 and -0.535, respectively) and Erise (r=-0.511 and -0.446, respectively). MVC was significantly correlated with Emax (r=-0.435 and -0.386, respectively). No significant correlations were found between DCE-MRI parameters and T stage, K-ras mutation, or microsatellite instability.

CONCLUSION

DCE-MRI may provide useful prognostic information in terms of histologic differentiation and angiogenesis in rectal cancer.

Patients with metastatic breast cancer using bevacizumab as a treatment: is there still a role for it?

OPINION STATEMENT

Over the last few decades, the angiogenesis mechanism has increasingly been studied and implicated in cancer pathophysiology. At present, it is known that angiogenesis plays a relevant role in tumor growth, and more importantly many new molecules exists can potentially interfere with this process. Bevacizumab, a humanized monoclonal antibody targeting the vascular endothelial growth factor A (VEGF-A) now commonly used in the treatment of colorectal, renal cell, and brain cancer, is the first anti-angiogenesis drug delivered in combination with chemotherapy that has consistently shown clinical efficacy in the treatment of breast cancer. Since the ECOG 2100 trial has shown that bevacizumab added to paclitaxel as a first-line treatment for advanced breast cancer nearly doubled the time to progression and tumor response rate, its approval was granted almost worldwide. However, other phase III trials revealed a smaller absolute improvement in progression-free survival (PFS) and response rates, and no trials yet have demonstrated survival enhancement which led to a great controversy and debate over the use of bevacizumab. The discrepancy between PFS and overall survival also raises the question of whether or not bevacizumab has been applied sub-optimally in some of the studies, if a predictive biomarker(s) exists to select the group of patients whom would receive the greatest benefit and what is the appropriate clinical end-point for approval and funding of new targeted agents. In this article we will review the bevacizumab mechanism of action and the clinical trials that assessed its benefit in the treatment of metastatic breast cancer (MBC).

Gadolinium- and 5-aminolevulinic acid-induced protoporphyrin IX levels in human gliomas: an ex vivo quantitative study to correlate protoporphyrin IX levels and blood-brain barrier breakdown

In recent years, 5-aminolevulinic acid (ALA)-induced protoporphyrin IX (PpIX) fluorescence guidance has been used as a surgical adjunct to improve the extent of resection of gliomas. Exogenous administration of ALA before surgery leads to the accumulation of red fluorescent PpIX in tumor tissue that the surgeon can visualize and thereby discriminate between normal and tumor tissue. Selective accumulation of PpIX has been linked to numerous factors, of which blood-brain barrier breakdown has been suggested to be a key factor. To test the hypothesis that PpIX concentration positively correlates with gadolinium (Gd) concentrations, we performed ex vivo measurements of PpIX and of Gd using inductively coupled plasma mass spectrometry, the latter as a quantitative biomarker of blood-brain barrier breakdown; this was corroborated with immunohistochemistry of microvascular density in surgical biopsies of patients undergoing fluorescence-guided surgery for glioma. We found positive correlations between PpIX concentration and Gd concentration (r = 0.58, p < 0.0001) and between PpIX concentration and microvascular density (r = 0.55, p < 0.0001), suggesting a significant, yet limited, association between blood-brain barrier breakdown and ALA-induced PpIX fluorescence. To our knowledge, this is the first time that Gd measurements by inductively coupled plasma mass spectrometry have been used in human gliomas.

An analysis of microvessel density in salivary gland tumours: a single centre study

BACKGROUNDS

Microvessel density (MVD) can be used for determining neoplastic neovascularisation. Tumour angiogenesis correlates with prognosis of cancers in many organs. The aims of this study were to evaluate MVD as demonstrated by CD31 and CD105 in salivary gland tumours (SGTs), and to correlate the MVD results with clinicopathological characteristics of the tumours.

MATERIALS AND METHODS

Using a retrospective cohort study design, we enrolled SGTs patients at the Faculty of Dentistry, Chulalongkorn University, Bangkok, Thailand, over the 22-year period. The predictor variables included demographic, anatomic and histopathological parameters. The outcome measure was average CD31-MVD and CD105-MVD counted by the "hot spot" method. Descriptive, uni- and bivariate statistics were computed, and P <0.05 was considered statistically significant.

RESULTS

The study sample consisted of 43 subjects with a mean age of 39.6 ± 17.8 years (range, 9-82), including 26 females (60.5%), diagnosed with SGTs. In this cohort, 58.1% of the cases were benign, and 83.7% were minor SGTs. There was a significant correlation between CD31-MVD and CD105-MVD (r = 0.8, P < 0.001), but mean CD31-MVD and CD105-MVD were 17.7 ± 9.3 and 12.8 ± 7.4, respectively (P = 0.009). Age, gender and tumour site were not individually associated with significant differences between CD31-MVD and CD105-MVD. Tumours with myoepithelial cells had lower MVD than those without myoepithelial cells (P = 0.04 for CD31; P = 0.03 for CD105). Only CD105-MVD showed statistical difference between benign and malignant SGTs (P = 0.01).

CONCLUSIONS

These results suggest that MVD in SGTs can be demonstrated by CD31 and CD105. Despite a strong correlation, CD31-MVD is always higher than CD105-MVD and cannot differentiate between benign and malignant SGTs. The presence of myoepithelial cells within SGTs affects the MVD analysis using either CD31 or CD105, while age, gender and tumour location do not.

VEGF-A-independent and angiogenesis-dependent tumour growth in patients with metastatic breast cancer

BACKGROUND The mechanisms of tumour progression during anti-VEGF-A treatment are poorly understood. PATIENTS AND MATERIALS Two patients with metastatic breast cancer are described who developed new metastases while receiving anti-VEGF-A treatment. Angiogenic parameters were determined by CD34/Ki67 double staining, Chalkley counts (CC) and endothelial cell proliferation fractions (ECP). RT-PCR Taqman low-density arrays with a gene panel of 94 angiogenesis-related genes were performed on both metastases and compared to 10 unselected primary breast tumours. RESULTS Both lesions showed a high and intermediate CC of, respectively, 7.5±0.62 and 4.8±0.2. Both lesions had elevated ECP values of 14% and 8%. Low-density array screening showed that VEGFR1 mRNA was overexpressed in both samples (z-score=7.85 and 7.81) compared to control samples (out of range [min-max]). Additional analysis confirmed this finding at the protein level by immunohistochemistry. CONCLUSION These observations suggest that tumour progression under continuous anti-VEGF-A continues to be angiogenesis dependent. Further exploration is needed to identify the mechanisms of anti-VEGF-A resistance in order to design combination-targeted therapies.