Christian Marinaccio

Insights in Hodgkin Lymphoma angiogenesis.

Angiogenesis is a hallmark of tumor growth and progression in solid and hematological malignancies. Different cellular components of the tumor microenvironment such as macrophages, mast cells, circulating endothelial cells and angiogenic factors, including vascular endothelial growth factor and its receptors are involved in the maintenance of Hodgkin Lymphoma. In this review article, we highlight relevant literature focusing on the relationships between angiogenesis and Hodgkin Lymphoma as well as discussing anti-angiogenic treatments in this malignancy.

Microvascular density, CD68 and tryptase expression in human Diffuse Large B-Cell Lymphoma

Diffuse Large B-cell Lymphoma (DLBCL) is the most common form of Non-Hodgkin lymphoma characterized by clinical and biological heterogeneity attributable both to the tumor cells and the complex tumor-microenvironment surrounding them. Tumor-associated macrophages (TAMs) and mast cells are two major components of the tumor inflammatory infiltrate with a definite role in enhancing tumor angiogenesis. In this study, we have investigated CD68 and tryptase expression and their relationship with microvascular density (MVD) in chemo-resistant and chemosensitive patients affected by DLBCL. CD68 and tryptase expression as well as MVD were increased in chemo-resistant patients when compared with chemosensitive patients. Tryptase expression showed a positive correlation with MVD, supporting a role for mast cell in DLBCL tumor angiogenesis, while CD68 correlation with MVD was not significant, indicating a different role for TAMs than angiogenesis in DLBCL.

Differential expression of angiogenic and anti-angiogenic molecules in the chick embryo chorioallantoic membrane and selected organs during embryonic development

In this study we have investigated by real time polymerase chain reaction (RT-PCR) the expression of cytokines, which are well known angiogenic and anti-angiogenic molecules, during chick embryo development in four organs, namely the chorioallantoic membrane (CAM), heart, liver and optic tectum at four different stages. We have studied the expression of vascular endothelial growth factor-A (VEGF-A), fibroblast growth factor-2 (FGF-2), angiopoietin-1 (ANG-1), hypoxia inducible factor-1 and -2 alpha (HIF-1α and HIF-2α), hepatocyte growth factor (HGF), and of endostatin. All the pro-angiogenic cytokines examined showed a progressive increase in their expression in brain, heart, and liver, through all the stages of development, and parallel endostatin reduces its expression. In contrast, in the CAM, all the pro-angiogenic factors examined, with the exception of ANG-1, showed a stably-decreased expression during development, whereas endostatin progressively increased its expression. The CAM as an extraembryonic membrane which mediates gas and nutrient exchange until hatching, may be considered an outer organ and not an intrinsic organ of the developing embryo in which the mechanisms regulating the development of the vascular tree are different.

Non-random spatial relationships between mast cells and microvessels in human endometrial carcinoma

Mast cells (MCs) accumulate in the stroma surrounding tumors, where they secrete angiogenic cytokines and proteases, and an increased number of MCs have been demonstrated in angiogenesis associated with solid and hematological tumors. The aim of this study is to contribute to the knowledge of distribution of MCs in tumors, investigating the pattern of distribution of tryptase-positive MCs around the blood vessels in human endometrial carcinoma samples by introducing a quantitative approach to characterize their spatial distribution. The results have shown that in human endometrial cancer bioptic specimens the spatial distribution of MCs shows significant deviation from randomness as compared with control group in which, instead, the spatial distribution of MCs is consistent with a random distribution. These findings confirm that MCs enhance tumor angiogenesis and their preferential localization along blood vessels and sites of new vessel formation sustaining the suggestion for an association between MCs and angiogenesis. However, this spatial association between vessels and MCs might simply reflect migrating MCs from the blood stream at vessel growing sites.

Angiogenesis and hyperbaric oxygen in the chick embryo chorioallantoic membrane.

Hyperbaric Oxygen Therapy (HBOT) is increasingly applied in different areas of medical practice. The oxy-hyperbarism effects are not well understood in cancer malignancy. One unique feature of cancer is the presence of hypoxic regions that are insensitive to conventional therapies. It is possible to alter the hypoxic state and produce reactive oxygen species for better treatment outcome by HBOT. In the present study, we determined the effects of HBOT on angiogenesis, a signature of cancer progression, by using the chick chorioallantoic membrane (CAM) in vivo assay. CAMs were exposed to 2.0 ATA (atmospheres absolute) for 30 min of hyperbaric oxygen on the 6(th) and 7(th) days of incubation (ED6, ED7). On the 10-11(th) day of incubation, CAMs were excised from eggs, fixed and analysed using APERIO ImageScope software. HBOT outcomes were evaluated quantifying the volumetric area occupied by blood vessels and calculating the number of blood vessel ramifications. Results indicated that CAMs treated at ED6 and ED7 had a significantly higher CAM vascularization and an increased number of blood vessel ramifications (+82% higher for ED6) compared to untreated CAMs (ED6=63.3±2.5 and ED7=57.7±5.5 vs. CTRL=34.7±2.5). Thus, HBOT induces an angiogenic response in treated CAMs through a classic sprouting mechanism.

Translocation of the proto-oncogene Bcl-6 in human glioblastoma multiforme

Bcl-6 translocation is a genetic alteration that is commonly detected in Primary Central Nervous System Lymphoma. The role of this protein in cerebral tumors is unclear. In this study we investigated Bcl-6 translocation and its transcriptional and translational levels in formalin-fixed, paraffin-embedded cerebral tissue sections from glioblastoma (GBM), low-grade glioma (Astrocytoma grade II and III), and meningioma patients, and correlated them with apoptotic processes and p53 and caspase-3 expression. The results showed a frequency of 36.6% of Bcl-6 translocation in GBM patients and a decreased expression in low-grade glioma patients, correlated with the severity of the disease. Bcl-6 translocation induced an overexpression of both Bcl-6 protein and messenger in GBM, inhibiting apoptotic processes and caspases 3 expression. On the contrary, in low-grade gliomas and meningiomas Bcl-6 expression was reduced, resulting in an increase of apoptotic processes. Finally, p53 expression levels in brain tumors were comparable to Bcl-6 levels. Overall, these data demonstrate, for the first time, that the Bcl-6 gene translocates in GBM patients and that its translocation and expression are correlated with apoptosis inhibition, indicating a key role for this gene in the control of cellular proliferation. This study offers further insights into glioblastoma biology, and supports Bcl-6 as a new diagnostic marker to evaluate the disease severity.

Isolation and characterization of neural stem cells from dystrophic mdx mouse

The blood-brain barrier (BBB) is altered in mdx mouse, an animal model to study Duchenne muscular dystrophy (DMD). Our previous work demonstrated that perivascular glial endfeet control the selective exchanges between blood and neuropil as well as the BBB development and integrity; the alterations of dystrophin and dystrophin-associated protein complex (DAPs) in the glial cells of mdx mouse, parallel damages of the BBB and increase in vascular permeability. The aim of this study was to improve our knowledge about brain cellular components in the mdx mouse through the isolation, for the first time, of the adult neural stem cells (ANSCs). We characterized them by FACS, electron microscopy, confocal immunofluorescence microscopy, Real Time-PCR and western blotting, and we studied the expression of the DAPs aquaporin-4 (AQP4), potassium channel Kir4.1, α- and β-dystroglycan (αDG, βDG), α-syntrophin (αSyn), and short dystrophin isoform Dp71 proteins. The results showed that the mdx ANSCs expressed CD133 and Nestin receptor as the control ones, but showed a reduction in Notch receptor and altered cell proliferation with an increment in the apoptotic nuclei. Ultrastructurally, they appeared 50% size reduced compared to control ones, with a few cytoplasmic organelles. Moreover, the mdx ANSCs are devoid in full length dystrophin 427, and they expressed post-transcriptional reduction in the Dp71 in parallel with the ubiquitin proteasome activation, and decrement of DAPs proteins which appeared diffused in the cytoplasm and not polarized on the stem cells plasmamembrane, as prevalently observed in the controls. Overall, these results indicate that structural and molecular alterations affect the neural stem cells in the dystrophic brain, whose increased apoptosis and reduced Dp71 and DAPs proteins expression, together with loss in Dp427 dystrophin, could be responsible of the altered mdx glial maintenance and differentiation and consequent failure in the vessels barrier control occurring in the adult dystrophic brain.

Interval sentinel lymph nodes in melanoma: a digital pathology analysis of Ki67 expression and microvascular density

Abstract The presence of interval sentinel lymph nodes in melanoma is documented in several studies, but controversies still exist about the management of these lymph nodes. In this study, an immunohistochemical evaluation of tumor cell proliferation and neo-angiogenesis has been performed with the aim of establishing a correlation between these two parameters between positive and negative interval sentinel lymph nodes. This retrospective study reviewed data of 23 patients diagnosed with melanoma. Bioptic specimens of interval sentinel lymph node were retrieved, and immunohistochemical reactions on tissue sections were performed using Ki67 as a marker of proliferation and CD31 as a blood vessel marker for the study of angiogenesis. The entire stained tissue sections for each case were digitized using Aperio Scanscope Cs whole-slide scanning platform and stored as high-resolution images. Image analysis was carried out on three selected fields of equal area using IHC Nuclear and Microvessel analysis algorithms to determine positive Ki67 nuclei and vessel number. Patients were divided into positive and negative interval sentinel lymph node groups, and the positive interval sentinel lymph node group was further divided into interval positive with micrometastasis and interval positive with macrometastasis subgroups. The analysis revealed a significant difference between positive and negative interval sentinel lymph nodes in the percentage of Ki67-positive nuclei and mean vessel number suggestive of an increased cellular proliferation and angiogenesis in positive interval sentinel lymph nodes. Further analysis in the interval positive lymph node group showed a significant difference between micro- and macrometastasis subgroups in the percentage of Ki67-positive nuclei and mean vessel number. Percentage of Ki67-positive nuclei was increased in the macrometastasis subgroup, while mean vessel number was increased in the micrometastasis subgroup. The results of this study suggest that the correlation between tumor cell proliferation and neo-angiogenesis in interval sentinel lymph nodes in melanoma could be used as a good predictive marker to distinguish interval positive sentinel lymph nodes with micrometastasis from interval positive lymph nodes with macrometastasis subgroups.

Angiogenic activity in vivo of the particulate matter (PM10)

BACKGROUND Particulate matter (PM) is the most efficient vehicle for the inhalation and absorption of toxic substances into the body. METHOD The present study was aimed at testing the hypothesis that PM10 samples collected on quartz filters exert an angiogenic activity in vivo in the chick embryo chorioallantoic membrane (CAM) assay. RESULTS When the low, medium, and high PM10 concentrations filters were tested in the CAM assay, an increasing number of microvessels was detectable after 4 days of applications of the filters. Moreover, at histological level, numerous microvessels and a dense inflammatory infiltrate were recognizable in the CAM mesenchyme. CONCLUSION Our data show a clear dose-response relationship between the dose variable (PM10 and Bap) and the outcome variable. So far, the PM10 target value is determined on the basis of regulatory agreements and is not health-based. In addition, the mere gravimetric measure of PM10 cannot be considered a fully reliable surrogate of the overall toxicity of the mixture.

A simple method of image analysis to estimate CAM vascularization by APERIO ImageScope software

The chick chorioallantoic membrane (CAM) assay is a well-established method to test the angiogenic stimulation or inhibition induced by molecules and cells administered onto the CAM. The quantification of blood vessels in the CAM assay relies on a semi-manual image analysis approach which can be time consuming when considering large experimental groups. Therefore we present here a simple and fast volumetric method to inspect differences in vascularization between experimental conditions related to the stimulation and inhibition of CAM angiogenesis based on the Positive Pixel Count algorithm embedded in the APERIO ImageScope software.