Atmospheric nanoparticles affect vascular function using a 3D human vascularized organotypic chip

Inhaled atmospheric nanoparticles (ANPs) can migrate into human blood vessels. However, the exact pathogenesis has not yet been well elucidated. In this study, a perfusable 3D human microvessel network was constructed in a microfluidic device. This functional 3D micro-tissue partly mimicked the physiological response of human vessels. Intravascular nanoparticles tend to adsorb proteins to form a protein corona. Based on this pathological response, vessel permeability and vasoconstriction resulting from ANP stimulation might be related to vascular inflammation. It mediated abnormal expression of nuclear factor-κB (NF-κB) and an influx of intracellular Ca²⁺ ([Ca²⁺]i). This biological behavior disturbed the normal expression of intercellular cell adhesion molecule 1 (ICAM-1) and vascular endothelial growth factor (VEGF). The imbalance of nitric oxide (NO) and endothelin-1 (ET-1) further resulted in endothelial cell contraction. All these bio-events induced the loss of tight junctions (ZO-1) which enhanced vessel permeability. Meanwhile, ANP induced-vascular toxicity was also found in mice. Our observations provide a plausible explanation for how the ANPs affect human vascular function. The vessel-on-chip provides a bridge between in vitro results and human responses. We aimed to use this human 3D functional microvascular model to mimic the physiological responses of human vessels. This model is suitable for the evaluation of vascular toxicity after the human vessel exposure to ANPs.

The role of the microvascular network structure on diffusion and consumption of anticancer drugs

We investigate the impact of microvascular geometry on the transport of drugs in solid tumors, focusing on the diffusion and consumption phenomena. We embrace recent advances in the asymptotic homogenization literature starting from a double Darcy-double advection-diffusion-reaction system of partial differential equations that is obtained exploiting the sharp length separation between the intercapillary distance and the average tumor size. The geometric information on the microvascular network is encoded into effective hydraulic conductivities and diffusivities, which are numerically computed by solving periodic cell problems on appropriate microscale representative cells. The coefficients are then injected into the macroscale equations, and these are solved for an isolated, vascularized spherical tumor. We consider the effect of vascular tortuosity on the transport of anticancer molecules, focusing on Vinblastine and Doxorubicin dynamics, which are considered as a tracer and as a highly interacting molecule, respectively. The computational model is able to quantify the treatment performance through the analysis of the interstitial drug concentration and the quantity of drug metabolized in the tumor. Our results show that both drug advection and diffusion are dramatically impaired by increasing geometrical complexity of the microvasculature, leading to nonoptimal absorption and delivery of therapeutic agents. However, this effect apparently has a minor role whenever the dynamics are mostly driven by metabolic reactions in the tumor interstitium, eg, for highly interacting molecules. In the latter case, anticancer therapies that aim at regularizing the microvasculature might not play a major role, and different strategies are to be developed.

The associations between serum VEGF, bFGF and endoglin levels with microvessel density and expression of proangiogenic factors in malignant and benign ovarian tumors

AIM OF THE STUDY

To investigate whether serum levels of VEGF, bFGF and endoglin correlate with tumor VEGF and bFGF expression or microvessel density (MVD) in ovarian cancer.

PATIENTS AND METHODS

Forty five patients with epithelial ovarian cancers (EOCs) and 38 patients with benign ovarian tumors (BOTs) were included into the study. Serum levels of VEGF, bFGF and endoglin were assessed using ELISA. The expression of VEGF and bFGF in tumor samples were evaluated using ELISA of supernatants obtained from tumor homogenization. MVD was analyzed using immunohistochemistry with antibodies against CD31, CD34 and CD105.

RESULTS

Serum VEGF levels were significantly higher in EOCs than in BOTs (436.6pg/ml [19.67-2860] vs 295.5pg/ml [123-539], P=0.025). Serum endoglin levels were lowered in the group EOCs when compared to BOTs (33,720g/ml [12,220-73,940] vs 42,390pg/ml [19,380-56,910], P=0.015). There were no differences in bFGF levels between studied groups. EOCs have significantly higher CD105 MVD (25 vessels/mm2 [0-57] vs 6 vessels/mm2 [0-70], P<0.001) and tumor VEGF (405.9pg/mg protein [0-3000] vs 2.225 [0-634.7], P<0.001) expression than BOTs, while, bFGF expression was higher in BOTs than in EOCs (2076pg/mg protein [668.1-8718] vs 847.3pg/mg protein [188.9-8333], P=0.003). In patients with EOCs we have observed negative correlation between serum VEGF concentration and its tissue expression (r Spearman=-0.571, P=0.0261), and serum VEGF concentration correlated positively with CD34-MVD (r Spearman=0.545, P=0.0289). In a multiple regression analysis we have observed only the negative correlation between serum VEGF and CD105-MVD (r=-0.5288, P=0.0427).

CONCLUSIONS

Serum VEGF is a useful marker for prediction of ovarian cancer MVD and tumor VEGF expression.

Correlational research of Golgi phosphorylation protein 3 expression in colorectal cancer

AIM: To investigate the effect of Golgi phosphorylation protein 3 (GOLPH3) expression on cell apoptosis, angiogenesis and prognosis in colorectal cancer (CRC).

METHODS: The expression of GOLPH3 in CRC tissues and normal colorectal mucosae was determined by immunohistochemistry in 62 patients. In addition, immunohistochemistry was also carried out to detect the expression of vascular endothelial growth factor (VEGF), CD34 and microvessel density (MVD). Terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling assay was used to determine the apoptotic index (AI). The Kaplan-Meier method was used to analyze the relationship between GOLPH3 expression and survival in another 123 CRC cases.

RESULTS: Compared with normal colorectal mucosae, a notably higher level of GOLPH3 protein expression was identified in CRC tissues (53.2% vs 24.2%, P < 0.05). Positive GOLPH3 expression was significantly associated with tumor invasion depth, TNM stage, and lymph node metastasis (P = 0.001; P = 0.020; P = 0.020; P < 0.05, respectively), but not with tumor length, tumor site, and age (P = 0.363; P = 0.819; P = 0.599; P > 0.05, respectively). VEGF expression and MVD in GOLPH3-positive CRC was significantly higher than in GOLPH3-negative CRC (VEGF: 69.7% vs 31.0%; MVD: 21.45 ± 9.39 vs 14.24 ± 8.97; P < 0.05). GOLPH3 expression was negatively correlated with AI in CRC as shown by Spearman correlation analysis (r = -0.320, P < 0.05). The 5-year survival rate in GOLPH3-negative CRC (69.4%) was significantly higher than in GOLPH3-positive CRC (48.6%) (log-rank test, P < 0.05).

CONCLUSION: High expression of GOLPH3 is found in CRC tissues. GOLPH3 expression may be a novel prognostic marker for CRC patients.

Interleukin-8 is a prognostic indicator in human hilar cholangiocarcinoma

Interleukin-8 (IL-8), matrix metalloproteinase-9 (MMP-9) and neovascularization have been implicated to be associated with biological processes, especially cancer progression. However, few studies have investigated the role of IL-8 in human hilar cholangiocarcinoma. In this study we detected the expression of IL-8 combined with MMP-9 and microvessel density (MVD) in hilar cholangiocarcinoma to evaluate their clinicopathological significance and prognostic value. A total of 62 patients with hilar cholangiocarcinoma who underwent curative surgery were enrolled in this study. The expression of IL-8, MMP-9 and MVD were examined immunohistochemically. The correlation of IL-8 with MMP-9 expression, MVD, clinicopathological features and survival time of patients were then analyzed. Expression of IL-8 was observed in 56.5% tumors, which was related to advanced TNM stage (P = 0.026) and tumor recurrence (P = 0.018). IL-8 had a positive correlation with MMP-9 expression and MVD. Furthermore, patients with high IL-8 expression had a significantly shorter overall survival than those with low IL-8 expression (P = 0.01). Multivariate analysis confirmed IL-8 as an independent prognostic factor (P = 0.005). In conclusion, IL-8 expression significantly correlated with MMP-9 expression and MVD, and IL-8 was a valuable prognostic factor for human hilar cholangiocarcinoma.

RhoC, vascular endothelial growth factor and microvascular density in esophageal squamous cell carcinoma

AIM: To investigate the expression of Ras homolog (Rho)C, vascular endothelial growth factor (VEGF) and CD105 in esophageal squamous cell carcinoma.

METHODS: Semi-quantitative reverse transcriptase polymerase chain reaction, in situ hybridization and immunohistochemical streptavidin-biotin- peroxidase methods were used to detect expression of RhoC mRNA and protein, and VEGF protein in 62 cases with esophageal squamous cell carcinoma, 31 cases with adjacent atypical hyperplastic tissues, and 62 cases with normal esophageal mucosa. CD105 antibody labeling was used to measure microvascular density. Expression levels were compared according to clinicopathologic and patient parameters.

RESULTS: Expression of RhoC mRNA showed a positive correlation with the protein level in esophageal squamous cell carcinoma, as well as with VEGF protein levels. RhoC mRNA expression was mainly located within the cytoplasm of the tumor cells, appearing as blue to purple particles by in situ hybridization. The differences in RhoC mRNA expression in esophageal squamous cell carcinoma, adjacent atypical hyperplasia and normal esophageal mucosa were significant (P < 0.05). The relative expression of RhoC mRNA in cancer tissues with lymph node metastasis was significantly higher than in the tissues without lymph node metastasis (P < 0.05). VEGF protein expression was consistent with microvascular density (t = 25.52, P < 0.05). Positive expression of VEGF protein in esophageal squamous cell carcinoma of different histologic gradings did not differ significantly. Positive expression of VEGF protein in carcinoma tissues with deep infiltration was significantly higher than in tissues with only superficial infiltration (P < 0.05). The positive expression of VEGF protein in cancer tissues with lymph node metastasis was significantly higher than in the tissues without lymph node metastasis (P < 0.05).

CONCLUSION: RhoC protein may upregulate VEGF expression, thereby promoting tumor angiogenesis. RhoC mRNA and protein expression was correlated with metastasis.

Does expression of glucose transporter protein-1 relate to prognosis and angiogenesis in osteosarcoma?

BACKGROUND

The survival of patients who present with nonmetastatic extremity osteosarcoma has dramatically improved, but there are some patients who do not respond to chemotherapy. The ability to identify patients with a poorer prognosis might allow us to target different therapy for these patients. Glucose transporter protein-1 (Glut-1), one of the key factors in glucose metabolism, has been reported to be an independent prognostic factor in various tumors. However, little is known about the role of the Glut-1 pathway in osteosarcoma.

QUESTIONS/PURPOSES

We asked (1) if Glut-1 expression is a prognostic marker for survival in patients with osteosarcoma, and (2) if there is a relationship between Glut-1 expression and tumor angiogenesis.

PATIENTS AND METHODS

Thirty-seven patients with resectable high-grade osteosarcomas treated between 1982 and 2007 were reviewed retrospectively. Patients were excluded if representative biopsy material and followup data were not available. The expression of Glut-1 and the number of CD34-positive microvessels for angiogenic activity were measured immunohistochemically. The median followup was 6 years 6 months (range, 11-211 months). Survival analyses were evaluated using the Kaplan-Meier method and the Cox proportional hazards model. The association between Glut-1 expression and microvessel density was analyzed using Student's t-test and chi-square test. For 12 (32.4%) of 37 patients with osteosarcoma, the expression of Glut-1 was positive, with four patients (10.8%) showing strong expression of Glut-1 protein.

RESULTS

The expression of Glut-1 correlated with a shorter disease-free survival period (relative risk, 20.13; 95% CI, 1.77-229.3; p=0.0016). The microvessel density mean value of positive Glut-1 expression (mean±SD, 26.5±19.4) was lower than that of negative expression (mean±SD, 46.4±35.3; Student's t-test, p=0.038). When more than 50 was defined as a high microvessel density, positive expression of Glut-1 was significantly associated with low microvessel density (chi-square test, p=0.049).

CONCLUSIONS

These findings indicate that Glut-1 is a potential predictor of survival in patients with osteosarcoma and that glucose metabolism may be negatively associated with angiogenesis. If substantiated in larger numbers of patients, these findings might stimulate the development of novel treatments for patients with a poorer prognosis.

LEVEL OF EVIDENCE

Level III, prognostic study. See the Instructions for Authors for a complete description of levels of evidence.

A qualitative investigation of RANKL, RANK and OPG in a rat model of transient ankylosis

INTRODUCTION

Previous studies have found ankylosis occurs as a part of the inflammatory process of aseptic root resorption initiated in a rat model. The physiologic mechanisms behind the development of dentoalveolar ankylosis and healing response are still unclear. While receptor activator of nuclear factor-κβ ligand (RANKL), receptor activator of nuclear factor-κβ (RANK) and osteoprotegerin (OPG) have gained momentum in the understanding of resorption, no study to date has investigated their role in dentoalveolar ankylosis.

AIMS

The aims of this study were to investigate if, and when, ankylosis occurred in the rat PDL, whether the resolution of ankylosis occurred with time and, finally, to observe the expression of RANKL, RANK and OPG during the ankylotic process.

MATERIALS AND METHODS

Dry ice was applied for 20 minutes to the upper right first molar crown of 15 eight-week-old, male Sprague-Dawley rats. An additional three rats served as untreated external controls. Groups of three rats were sacrificed after the thermal insult on day 0, 4, 7, 14 and 28 respectively. Each maxilla was dissected out and processed for histological examination and RANKL, OPG and RANK immunohistochemistry.

RESULTS

By the use of light microscopy and H&E staining, no ankylosis was detected in the external control group and the experimental groups at days 0 and 4. On day 7, disruption within the periodontal ligament was observed in the interradicular region and the initial signs of ankylosis were seen in the form of finger-like projections extending from the alveolar bone towards the cementum. Fourteen days after the thermal insult, all animals exhibited extensive ankylosis that spanned the entire interradicular periodontal space. At 28 days, the development of ankylosis appeared to have ceased and repair was observed, together with an intact periodontal ligament in all but one rat. Positive staining results were obtained with RANKL, RANK and OPG antibodies. The expressions of RANKL, RANK and OPG were similar in the external control group, 0-, 4-, and 28-day experimental groups. In the 7- and 14-day experimental groups, RANKL, RANK and OPG were expressed in the blood vessels within the ankylotic regions.

CONCLUSIONS

During the development of ankylosis and its resolution, it was concluded from their simultaneous presence that there is a complex interaction between RANKL, RANK and OPG that requires further investigation.

Esophageal early basaloid squamous carcinoma with unusual narrowband imaging magnified endoscopy findings

Basaloid squamous carcinoma (BSC) is a rare variant of esophageal cancer. There are very few reports of “early” BSC. Here we report a case of early BSC with unusual findings by narrowband imaging magnified endoscopy (NBI-ME). A 70-year-old man with a middle thoracic esophageal tumor was referred to our hospital. White-light endoscopy revealed a reddish depressed lesion 5 mm in diameter having a subepithelial tumor-like prominence with a gentle rising slope. NBI-ME revealed irregular loop-shaped microvessels coexistent with thick irregularly branched non-looped vessels. Iodine staining revealed a pale brown lesion. We performed endoscopic submucosal dissection for diagnostic treatment. Histologic examination showed the proliferation of basal cell-like hyperchromatic tumor cells in the lamina propria and with slight invasion into the submucosa at a depth of 320 μm. The tumor cells formed solid nests and microcystic structures, containing an Alcian blue-positive mucoid matrix. The surface was covered with squamous epithelium without cellular atypia. Thin vessels were observed in the intra-epithelial papilla and thick vessels were observed around the solid nests beneath the epithelium. Based on these findings together, we diagnosed the lesion as BSC. In this case, the NBI-ME findings differed from those of typical squamous cell carcinoma in that both non-invasive cancer-like irregular loop-shaped microvessels coexisted with massively invasive cancer-like thick non-looped vessels. We speculate that the looped and non-looped vessels observed by NBI-ME histologically corresponded to thin vessels in the intra-epithelial papilla and thick vessels around the tumor nests, respectively. These NBI-ME findings might be a feature of early esophageal BSC.

Prognostic role of microvessel density in patients with renal cell carcinoma: a meta-analysis

Microvessel density (MVD), an indicator of angiogenesis, has been proposed to predict prognosis of patients with renal cell carcinoma (RCC), but its ability to predict survival of patients with RCC remains controversial. The present study sought to address this question rigorously by systematically reviewing the literature on MVD and RCC prognosis. We identified relevant studies in PubMed, EMBASE and the Cochrane Library, and two reviewers independently assessed study quality and extracted relevant data to compare survival based on MVD stratification in patients with RCC. We identified 15 studies that satisfied the inclusion criteria; eight studies assessed MVD in surgical samples by immunohistochemistry to label factor VIII; four studies, by immunohistochemistry to label CD34; two studies, CD31; and one study, CD105. Survival meta-analysis was performed using data pooled from 10 studies: five based on factor VIII, two based on CD34, two based on CD31 and one based on CD105. The overall survival hazard ratio describing the relationship between MVD and survival in all 10 pooled studies was 0.964 (95% CI: 0.873-1.065), while the individual hazard ratios for pooled studies based on factor VIII were 1.673 (95% CI: 0.860-3.252); CD34, 0.903 (95% CI: 0.853-0.956); and CD31, 0.926 (95% CI: 0.868-0.989). The corresponding result for the sole trial based on CD105 was 0.1759 (95% CI: 0.036-0.856). These findings suggest that MVD is not reliably associated with survival time of patients with RCC, which may reflect the need to take into account whether the microvasculature is differentiated or not. MVD as currently calculated may not be an ideal prognostic factor for patients with RCC.

Intravascular large B-cell lymphoma confirmed by lung biopsy

Intravascular lymphoma is a very rare form of large B-cell non-Hodgkin's lymphoma which is characterized by selective growth of lymphoma cells within the lumina of small blood vessels. We report a 64-year-old woman visited hospital because of persistent cough, intermittent high fever as high as 38.7 °C and occasional shortness of breath. Her chest CT showed left upper lobe pneumonia and tuberculosis skin test (PPD test) was positive. She was suspected with tuberculosis and treated with anti-tuberculosis drugs. However, her symptoms and general condition deteriorated, and she visited our hospital. She had no abnormal findings on physical examination, but had abnormal laboratory findings, including decreased hemoglobin, elevated LDH and C-reactive protein. Arterial blood gas analysis showed moderate hypoxaemia. A chest radiograph showed pneumonia in whole lung and CT showed diffused ground glass opacities in both lung fields. Lung biopsy confirmed a diagnosis of intravascular large B-cell lymphoma. Primary pulmonary manifestation is very rare. The diagnosis is based on the histopathology and immunohistochemistry.

Microvessel density and expression of vascular endothelial growth factor and its receptors in different subtypes of primary cutaneous B-cell lymphoma

A proangiogenic micromilieu is associated with a worse prognosis in systemic lymphoma. Hence, targeting the tumour microenvironment and its vasculature has evolved as a promising novel treatment strategy. The role of tumour neoangiogenesis in cutaneous B-cell lymphoma, however, has not yet been elucidated. Therefore, we examined the expression of vascular endothelial growth factor (VEGF) and its receptors VEGFR-1 and VEGFR-2, as well as microvessel density by immunohistochemistry in paraffin-embedded specimens of different subtypes of primary cutaneous B-cell lymphomas, systemic diffuse large B-cell lymphoma, and cutaneous B-cell pseudolymphoma. Primary cutaneous large B-cell lymphoma (PCLBCL) were characterized by significantly higher intratumoral expression levels of VEGF and its receptors in comparison with the indolent lymphoma subtypes. Moreover, PCLBCL exhibited significantly higher intratumoral microvessel counts. Our study provides evidence that the most aggressive subtype of cutaneous B-cell lymphoma, PCLBCL, is characterized by a proangiogenic micromilieu.

Hollow three-dimensional endothelialized microvessel networks based on femtosecond laser ablation

In this study, a novel method for the fabrication of hollow three-dimensional (3D) poly(lactic-co-glycolic acid) (PLGA) microvessel scaffolds is proposed. In this novel fabrication method, a salt ingot, which was used as a temporary frame to define the shape of the desired scaffold, was fabricated by extrusion molding. The salt ingot was immersed in a PLGA solution and the PGLA enveloped the ingot entirely. The femtosecond laser ablation technique was used for ablating the desired pattern on the PLGA layer and then the salt ingot was completely dissolved in distilled deionized water. A hollow 3D PLGA scaffold was obtained using this process on which bovine endothelial cells (BECs) were then cultured. Scanning electron microscopy (SEM) and fluorescent images of the cell seeding demonstrate that the BECs adhered and grew well on both the side-wall of the branches and the surroundings of each branch.

In vivo assessment of human burn scars through automated quantification of vascularity using optical coherence tomography

In scars arising from burns, objective assessment of vascularity is important in the early identification of pathological scarring, and in the assessment of progression and treatment response. We demonstrate the first clinical assessment and automated quantification of vascularity in cutaneous burn scars of human patients in vivo that uses optical coherence tomography (OCT). Scar microvasculature was delineated in three-dimensional OCT images using speckle decorrelation. The diameter and area density of blood vessels were automatically quantified. A substantial increase was observed in the measured density of vasculature in hypertrophic scar tissues (38%) when compared against normal, unscarred skin (22%). A proliferation of larger vessels (diameter≥100  μm) was revealed in hypertrophic scarring, which was absent from normal scars and normal skin over the investigated physical depth range of 600 μm. This study establishes the feasibility of this methodology as a means of clinical monitoring of scar progression.

Multimodal in vivo imaging exposes the voyage of nanoparticles in tumor microcirculation

Tumors present numerous biobarriers to the successful delivery of nanoparticles. Decreased blood flow and high interstitial pressure in tumors dictate the degree of resistance to extravasation of nanoparticles. To understand how a nanoparticle can overcome these biobarriers, we developed a multimodal in vivo imaging methodology, which enabled the noninvasive measurement of microvascular parameters and deposition of nanoparticles at the microscopic scale. To monitor the spatiotemporal progression of tumor vasculature and its vascular permeability to nanoparticles at the microcapillary level, we developed a quantitative in vivo imaging method using an iodinated liposomal contrast agent and a micro-CT. Following perfusion CT for quantitative assessment of blood flow, small animal fluorescence molecular tomography was used to image the in vivo fate of cocktails containing liposomes of different sizes labeled with different NIR fluorophores. The animal studies showed that the deposition of liposomes depended on local blood flow. Considering tumor regions of different blood flow, the deposition of liposomes followed a size-dependent pattern. In general, the larger liposomes effectively extravasated in fast flow regions, while smaller liposomes performed better in slow flow regions. We also evaluated whether the tumor retention of nanoparticles is dictated by targeting them to a receptor overexpressed by the cancer cells. Targeting of 100 nm liposomes showed no benefits at any flow rate. However, active targeting of 30 nm liposomes substantially increased their deposition in slow flow tumor regions (∼12-fold increase), which suggested that targeting prevented the washout of the smaller nanoparticles from the tumor interstitium back to blood circulation.

Engineering of functional, perfusable 3D microvascular networks on a chip

Generating perfusable 3D microvessels in vitro is an important goal for tissue engineering, as well as for reliable modelling of blood vessel function. To date, in vitro blood vessel models have not been able to accurately reproduce the dynamics and responses of endothelial cells to grow perfusable and functional 3D vascular networks. Here we describe a microfluidic-based platform whereby we model natural cellular programs found during normal development and angiogenesis to form perfusable networks of intact 3D microvessels as well as tumor vasculatures based on the spatially controlled co-culture of endothelial cells with stromal fibroblasts, pericytes or cancer cells. The microvessels possess the characteristic morphological and biochemical markers of in vivo blood vessels, and exhibit strong barrier function and long-term stability. An open, unobstructed microvasculature allows the delivery of nutrients, chemical compounds, biomolecules and cell suspensions, as well as flow-induced mechanical stimuli into the luminal space of the endothelium, and exhibits faithful responses to physiological shear stress as demonstrated by cytoskeleton rearrangement and increased nitric oxide synthesis. This simple and versatile platform provides a wide range of applications in vascular physiology studies as well as in developing vascularized organ-on-a-chip and human disease models for pharmaceutical screening.

Reflection-mode multifocal optical-resolution photoacoustic microscopy

Compared with single-focus optical-resolution photoacoustic microscopy (OR-PAM), multifocal OR-PAM utilizes both multifocal optical illumination and an ultrasonic array transducer, significantly increasing the imaging speed. A reflection-mode multifocal OR-PAM system based on a microlens array that provides multiple foci as well as an ultrasonic array transducer that receives the excited photoacoustic waves from all foci simultaneously is presented. Using a customized microprism to reflect the incident laser beam to the microlens array, the multiple optical foci are aligned confocally with the focal zone of the ultrasonic array transducer. Experiments show the reflection-mode multifocal OR-PAM is capable of imaging microvessels in vivo, and it can image a 6×5×2.5  mm³ volume at 16 μm lateral resolution in ∼2.5  min, which was limited by the signal multiplexing ratio and laser pulse repetition rate.

Margination propensity of vascular-targeted spheres from blood flow in a microfluidic model of human microvessels

Many variants of vascular-targeted carriers (VTCs) have been investigated for therapeutic intervention in several human diseases. However, in order to optimize the functionality of VTC in vivo, carriers' physical properties, such as size and shape, are important considerations for a VTC design that evades the reticuloendothelial system (RES) and successfully interacts with the targeted vessel wall. Nonetheless, little evidence has been presented on the role of size in VTC's interactions with the vascular wall, particularly in the microcirculation. Thus, in this work, we explore how particle size, along with hemodynamics (blood shear rate and vessel size) and hemorheology (blood hematocrit) affect the capacity for spheres to marginate (localize and adhere) to inflamed endothelium in a microfluidic model of human microvessels. Microspheres, particularly the 2 μm spheres, were found to show disproportionately higher margination than nanospheres in all hemodynamic conditions evaluated due to the poor ability of the latter to localize to the wall region from midstream. This work represents the first evidence that nanospheres may not exhibit "near wall excess" in microvessels, e.g., arterioles and venules, and therefore may not be suitable for imaging and drug delivery applications in cancer and other diseases affecting microvessels.

The CD34-microvascular density in colorectal cancer patients

PURPOSE

To investigate the influence of the angiogenesis parameter CD34 microvascular density (MVD) on overall survival of colorectal cancer (CRC) patients.

METHODS

Thirty-one CRC patients were followed-up for 72 months after curative colorectal operation. Blood vessels measurement was done using the CD34-MVD immunochemistry method, and light microscopy.

RESULTS

MVD was inversely correlated with patients' survival. MVD value < 35 proved as independent good prognostic factor, and patients with this value lived during the 72-month follow up after surgery, while a MVD value > 65 was an independent poor prognostic factor and such patients died within 11 months after radical surgery for CRC (p<0.01).

CONCLUSION

According to these results, the CD34-MVD seems to be a significant prognosticator of overall survival in CRC patients.

Labeling of microvessel density, lymphatic vessel density and potential role of proangiogenic and lymphangiogenic factors as a predictive/prognostic factors after radiotherapy in patients with cervical cancer

INTRODUCTION

Angiogenesis, formation of a new blood vessel from the existing vascular network, is essential for tumor growth, progression and metastasis. Vascular endothelial growth factor (VEGF) has been identified to be one of the most important factors of angiogenesis. VEGF-C, a novel member of the family, is a relatively specific lymphangiogenic growth factor. It is tempting to suggest that cervical cancer is one of the most common malignancies in a woman's life. Its prognostic factors are tumor stage, lymph node status, histologic type, level of hemoglobin. However, little is known about prognostic or/and predictive significance of angiogenesis in cervical cancer.

OBJECTIVE

This prospective study is an attempt to evaluate serum VEGF-A, VEGF-C, microvessel density (MVD), and lymphatic vessel density (LMVD) in cervical cancer and the correlations with clinicopathologic features.

MATERIAL AND METHODS

Blood samples were collected from 58 patients affected by FIGO I-IV stage cervical cancer, who were admitted to the Department of Oncology and Brachytherapy Collegium Medicum in Bydgoszcz of Nicolaus Copernicus University. Serum VEGF-A/VEGF-C concentrate was determined by means of a quantitative sandwich enzyme immunoassay (ELISA). All tumor samples were taken from cross section during the first brachytherapy. Then they were examined by immunohistochemical studies with podoplanin antibody and anti-CD31 antibody. The present analysis was used to evaluate MVD and LMVD.

RESULTS

The median serum VEGF-A was 734.76 pg/ml (range from 86.39 pg/ml - 2200.00 pg/ml), and VEGF-A was only correlated with after treatment hemoglobin concentration (p = 0.046, R = -0.3450). The median serum VEGF-C was 145.72 pg/ml (range 131.08 - 233.60 pg/ml). Serum VEGF-C levels measured in patients were associated with primary tumor size. We observed significantly higher serum VEGF-C in localized disease (FIGO I, II) in comparison to advanced tumors (232.44 pg/ml vs 152.45 pg/ml; p = 0.034). The median LMVD was 6.25 (range 3.5-10.0) and median blood vessel density was 12.5 (range 9.5-23.0). We found significantly higher lymphatic vessel density in patients with Gl/G2 grade of differentiation than in those with G3 (9.93 vs 6.25; p = 0.0398). We observed a statistically significant correlation between MVD and LMVD; (p = 0.032).

CONCLUSION

In conclusion, our study suggests that serum VEGF-A, VEGF-C, LMVD and MVD play an important role in tumor growth and progression in cervical cancer. Nonetheless, further studies are essential to explore the underlying mechanism.

Vascular CXCR4 expression - a novel antiangiogenic target in gastric cancer?

BACKGROUND

G-protein-coupled receptors (GPCRs) are prime candidates for novel cancer prevention and treatment strategies. We searched for differentially expressed GPCRs in node positive gastric carcinomas.

METHODOLOGY/PRINCIPAL FINDINGS

Differential expression of GPCRs in three node positive vs. three node negative intestinal type gastric carcinomas was analyzed by gene array technology. The candidate genes CXCL12 and its receptor CXCR4 were validated by real-time reverse-transcription polymerase chain reaction in an independent set of 37 gastric carcinomas. Translation was studied by immunohistochemistry in 347 gastric carcinomas using tissue microarrays as well as in 61 matching lymph node metastases. Protein expression was correlated with clinicopathological patient characteristics and survival. 52 GPCRs and GPCR-related genes were up- or down-regulated in node positive gastric cancer, including CXCL12. Differential expression of CXCL12 was confirmed by RT-PCR and correlated with local tumour growth. CXCL12 immunopositivity was negatively associated with distant metastases and tumour grade. Only 17% of gastric carcinomas showed CXCR4 immunopositive tumour cells, which was associated with higher local tumour extent. 29% of gastric carcinomas showed CXCR4 positive tumour microvessels. Vascular CXCR4 expression was significantly associated with higher local tumour extent as well as higher UICC-stages. When expressing both, CXCL12 in tumour cells and CXCR4 in tumour microvessels, these tumours also were highly significantly associated with higher T- and UICC-stages. Three lymph node metastases revealed vascular CXCR4 expression while tumour cells completely lacked CXCR4 in all cases. The expression of CXCL12 and CXCR4 had no impact on patient survival.

CONCLUSIONS/SIGNIFICANCE

Our results substantiate the significance of GPCRs on the biology of gastric carcinomas and provide evidence that the CXCL12-CXCR4 pathway might be a novel promising antiangiogenic target for the treatment of gastric carcinomas.

Microvessel density and area in pituitary microadenomas

Microvessel density (MVD) and area (MVA) were assessed in 53 clinically silent pituitary microadenomas and in surrounding normal pituitary tissue using CD34 immunostaining and digital image analysis system. Twenty-one microadenomas (40%) were avascular; in the others, both MVD and MVA were significantly lower than in the normal pituitary tissue. No significant differences in MVD and MVA were found between hormonally immunonegative and immunopositive tumors or between different hormonal subtypes of immunopositive microadenomas. In microadenomas and in normal pituitary tissue, MVD and MVA were not significantly influenced by age or sex. These results suggest that pituitary adenomas at early developmental stage are either avascular or significantly less vascular than normal pituitary tissue and that differences in vascularity of pituitary adenomas associated with the variables of sex, age, clinical presentation and immunohistochemical phenotype reported in the literature can evolve with tumor growth and possibly acquire statistical significance in large macroadenomas.

[Significance of caveolin-1 expression in primary lung cancer]

OBJECTIVE

To study the expression of caveolin-1 in primary lung cancer and its relationship with microvessel density and clinicopathologic parameters.

METHODS

Immunohistochemical study for caveolin-1 and CD34 was performed on paraffin sections of 154 cases of primary lung cancer and adjacent non-neoplastic lung parenchymal tissue, as well as 36 cases with nodal metastasis. Microvessel density was analyzed by CD34 immunostaining. Western blot assay was also employed in tumor and non-neoplastic lung tissues of the 50 cases (25 cases of pulmonary squamous cell carcinoma and 25 cases of pulmonary adenocarcinoma) with fresh specimens available.

RESULTS

Immunohistochemical study showed that non-neoplastic bronchial and alveolar epithelium was positive for caveolin-1 (membranous and cytoplasmic). The expression rate of caveolin-1 in lung cancer was 59.1%, which was significantly lower than that in normal lung tissues (P < 0.01). Western blot assay confirmed that the expression of caveolin-1 in pulmonary squamous cell carcinoma and adenocarcinoma was lower than in surrounding non-neoplastic lung tissues (P < 0.01). Caveolin-1 expression in pulmonary small cell carcinoma (7.1%) was significantly lower than that in non-small cell carcinoma (64.3%) (P < 0.01). Within the group of non-small cell carcinoma, the expression of caveolin-1 was much higher in patients with lymph node metastasis (P = 0.005). The expression was also higher in stage III and IV than in stage I and II disease (P = 0.042).

CONCLUSIONS

The expression of caveolin-1 is lower in lung cancer tissues than that in non-small cell carcinoma, it is also significantly correlated with tumor stage and lymph node metastasis. Caveolin-1 may play some role in the progression of pulmonary non-small cell carcinoma.