Cristiana Simionescu

VEGF expression and angiogenesis in oral squamous cell carcinoma: an immunohistochemical and morphometric study

Angiogenesis is involved in tumor progression of oral squamous cell carcinoma (OSCC). In this study, we have investigated by immunohistochemistry vascular endothelial growth factor (VEGF) expression in tumor cells and we have correlated VEGF expression to microvessel area, evaluated by using CD105 as a marker of endothelial cells, in bioptic specimens of 54 human OSCC. Results demonstrated that VEGF is highly expressed in OSCC tumor specimens when compared to pre-neoplastic and normal tissues, without differences between the edge and inside the tumor. Moreover, VEGF expression is reduced in poor differentiated OSCC tumors when compared to moderate and good differentiated forms, and tumor microvessel area is higher in tumors when compared to pre-neoplastic lesions and normal tissues. Finally, VEGF and CD105 may be considered as reliable markers of tumor angiogenesis and progression in OSCC, even if we did not demonstrate any correlation between VEGF expression, tumor microvascular area, clinical stage, and lymph node status.

Different Dynamics of Aquaporin 4 and Glutamate Transporter-1 Distribution in the Perineuronal and Perivascular Compartments during Ischemic Stroke

Aquaporin‐4 (AQP4) and glutamate transporter‐1 (GLT‐1) represent the major water and glutamate astrocyte buffering gateways in the brain. Utilizing perilesional ischemic human cortices, we have performed here for the first time an integrative assessment on both AQP4 and GLT‐1, and on their proximity to blood vessels and neurons. Counting the relative number of AQP4±/GLT‐1±/glial fibrillary acidic protein± cells showed that double‐positive variants were overall most frequent, and their number tended to decrease from organized and recent perilesional cortices to controls. AQP4/GLT‐1 colocalization showed higher coefficients for the perilesional cortices compared with controls, suggesting an increased water/glutamate‐buffering capability. Distance frequency analysis of AQP4/GLT‐1 in relationship to neurons showed that both markers were concentrated at 20–40u2009μm around the perikarya; with AQP4 being more abundant in close proximity, these differences were not being driven by changes in neuropil density alone. Our study suggests a dual, simultaneous astrocytic function depending on the relative distance to neurons and vessels, with increased water and glutamate‐buffering capability in the mid perineuronal space, and an increased water‐buffering capability in the immediate perineuronal space, even higher than around vessels. Thus, adding specific AQP4/GLT‐1 modulator agents selectively depending on the acute/chronic phase of stroke might increase the efficacy of existing treatments.

Matrix metalloproteinase-9 expression in the nuclear compartment of neurons and glial cells in aging and stroke

Matrix metalloproteinases (MMPs) are well‐recognized denominators for extracellular matrix remodeling in the pathology of both ischemic and hemorrhagic strokes. Recent data on non‐nervous system tissue showed intracellular and even intranuclear localizations for different MMPs, and together with this, a plethora of new functions have been proposed for these intracellular active enzymes, but are mostly related to apoptosis induction and malign transformation. In neurons and glial cells, on human tissue, animal models and cell cultures, different active MMPs have been also proven to be located in the intra‐cytoplasmic or intra‐nuclear compartments, with no clear‐cut function. In the present study we show for the first time on human tissue the nuclear expression of MMP‐9, mainly in neurons and to a lesser extent in astrocytes. We have studied ischemic and hemorrhagic stroke patients, as well as aged control patients. Age and ischemic suffering seemed to be the best predictors for an elevated MMP‐9 nuclear expression, and there was no evidence of a clear‐cut extracellular proteolytic activity for this compartment, as revealed by intact vascular basement membranes and assessment of vascular densities. More, the majority of the cells expressing MMP‐9 in the nuclear compartment also co‐expressed activated‐caspase 3, indicating a possible link between nuclear MMP‐9 localization and apoptosis in neuronal and glial cells following an ischemic or hemorrhagic event. These results, besides showing for the first time the nuclear localization of MMP‐9 on a large series of human stroke and aged brain tissues, raise new questions regarding the unknown spectrum of the functions MMPs in human CNS pathology.

Tumor angiogenesis, macrophages and mast cell microdensities in endometrioid endometrial carcinoma

The present study aimed to observe and compare the values of microvessel density (MVD), mast cell microdensity (McMD) and macrophage microdensity (MphMD) in intratumoral areas compared with the advancing edges, and to assess any correlations between these values and the degree and stage of the neoplasia. The cases of 52 patients who were diagnosed with endometrial carcinoma between 2003 and 2011 were analyzed, the majority of which were in the first stage of the disease (44 cases). Double sequential immunohistochemistry and the hot-spot counting method were used to assess the MVD (CD105+ MVD), McMD [tryptase+ (Try+) McMD] and MphMD (CD68+ MphMD) densities. The χ2 test, paired Student’s t-test and the Pearson correlation index were used to assess the significance of the results. A weak correlation was observed at the advancing edge only, between CD105+ MVD and Try+ McMD (P=0.039). No significant differences were identified in the analysis of CD105+ MVD, Try+ McMD and CD68+ MphMD, but wide variations in their distribution were observed. Depending on the tumor stage, CD105+ MVD exhibited an intratumoral, indirect correlation with Try+ McMD for stage IA (P=0.026) and II (P=0.013) tumors. CD105+ MVD presented an indirect correlation with CD68+ MphMD in stage IB tumors (P=0.016) and at the advancing edge for well-differentiated tumors (P=0.027). An analysis of the correlation between CD68+ MphMD and Try+ McMD indicated that the intratumoral levels of CD68+ MphMD were directly proportional with the Try+ McMD values in well-differentiated (P=0.005) and stage II (P=0.012) tumors, while at the front of the invasion, this correlation was indirect (P=0.010) in stage II tumors. In endometrioid endometrial carcinoma (EEC), angiogenesis is at its most active at the advancing edge of the tumor, where mast cells play a pro-angiogenic role.

Fractal Analysis and the Diagnostic Usefulness of Silver Staining Nucleolar Organizer Regions in Prostate Adenocarcinoma

Pathological diagnosis of prostate adenocarcinoma often requires complementary methods. On prostate biopsy tissue from 39 patients including benign nodular hyperplasia (BNH), atypical adenomatous hyperplasia (AAH), and adenocarcinomas, we have performed combined histochemical-immunohistochemical stainings for argyrophilic nucleolar organizer regions (AgNORs) and glandular basal cells. After ascertaining the pathology, we have analyzed the number, roundness, area, and fractal dimension of individual AgNORs or of their skeleton-filtered maps. We have optimized here for the first time a combination of AgNOR morphological denominators that would reflect best the differences between these pathologies. The analysis of AgNORs roundness, averaged from large composite images, revealed clear-cut lower values in adenocarcinomas compared to benign and atypical lesions but with no differences between different Gleason scores. Fractal dimension (FD) of AgNOR silhouettes not only revealed significant lower values for global cancer images compared to AAH and BNH images, but was also able to differentiate between Gleason pattern 2 and Gleason patterns 3–5 adenocarcinomas. Plotting the frequency distribution of the FDs for different pathologies showed clear differences between all Gleason patterns and BNH. Together with existing morphological classifiers, AgNOR analysis might contribute to a faster and more reliable machine-assisted screening of prostatic adenocarcinoma, as an essential aid for pathologists.