1,721,144 research outputs found
Correlative evidence that tumor cell-derived caveolin 1 mediates angiogenesis
No full textno abstract availabl
Evaluation of neo-angiogenesis in a case of chordoid meningioma
No full textChordoid is a rare variant of meningioma that displays a high recurrence rate. In this study we evaluated the immunohistochemical expression of factors that regulate the neo-angiogenesis process in a case of chordoid meningioma with an adverse clinical course. A high microvessel density (MVD), as well as high VEGF and VEGF-R1 expression, was encountered in this tumor. By contrast, the anti-angiogenic factor semaphorin3A, highly expressed in this chordoid meningioma, was ineffective because of the absence of its receptor neuropilin-1. We suggest that VEGF expression and MVD may represent significant prognostic factors in chordoid meningiomas
Meningioma with zellballen growth pattern: histological and immunohistochemical findings
No full textno abstract availabl
HOXB13 is not expressed in pleomorphic giant cell carcinoma of the bladder
No full textThe paper describes the utility of HOXB13 in distinguishing prostatic vs urothelial origin of pleomorphic carcinoma
Angiogenesis in meningiomas
No full textNeoangiogenesis has been correlated to biological aggressiveness and an adverse clinical course of several neoplasias. Its prognostic role in meningiomas appears to be controversial. Nonetheless, if adequately quantified with specific markers and appropriate scoring methods, angiogenesis seems to be significantly associated with a high growth fraction, development of recurrences and shorter overall survival of meningiomas. As a consequence, neoangiogenesis may represent a target for therapies aimed at reducing the growth of inoperable meningiomas or recurrence risk of totally resected tumors. Even more significantly, the identification of the factors that mediate angiogenesis in meningiomas could help us to determine appropriate novel anti-angiogenic therapies for these tumors. Herein the methods for quantification of angiogenesis as well as its regulating factors in meningiomas are reviewed
Meningiomas: Role of Semaphorin3A Protein in Antiangiogenesis
No full textMeningiomas represent frequent tumors mainly characterized by a benign histology and an indolent clinical course. The histological grade and extent of surgical resection are considered to be the most powerful prognosticators for these neoplasias. Nonetheless, a percentage of meningiomas do display relapses despite a total macroscopic resection, although the reasons of this phenomenon still remain to be fully clarified. Herein the prognostic value of angiogenesis and of the expression of its regulators in completely surgically resected meningiomas is discussed. In particular, the role of semaphorin3A (SEMA3A) in the regulation of angiogenesis and the correlation between its expression and the risk of recurrence of meningiomas are illustrate
Poorly differentiated clusters in colorectal liver metastases: Prognostic significance in synchronous and metachronous metastases
No full textNo abstract availabl
NGAL immunohistochemical expression in brain primary and metastatic tumors
No full textA significant association has been recently shown between the expression of neutrophil gelatinase-associated lipocalin (NGAL) in tumors and its urinary levels. Thus NGAL urinary detection has been proposed as a method for the early diagnosis of brain tumors. In view of this, the objective of this study was to investigate whether NGAL expression differs according to brain tumor type or in primary vs. metastatic brain neolasias. 42 surgically resected formalin fixed and paraffin embedded neoplasias, including 15 cases of brain metastasis and 27 cases of primary central nervous system (CNS) tumors (11 meningiomas; 1 pilocytic astrocytoma, 2 diffuse astrocytomas, 2 oligoastrocytomas, 2 oligodendrogliomas, 1 anaplastic oligoastrocytoma, 7 glioblastomas, 1 ependymoma) were submitted to the immunohistochemical procedure. Sections were incubated overnight with the primary antibody against NGAL. NGAL staining was found in all the analyzed glioblastomas and in the anaplastic oligoastrocytoma. No NGAL immuno-expression was evidenced in all the other cases. A statistically significant correlation was demonstrated between NGAL presence and high proliferation index in the primary tumors. In conclusion, our findings suggest that NGAL expression is restricted to high grade gliomas among primary brain tumors, and that brain metastases do not express this protein. Considering the correlation between NGAL expression in tumors and its urinary levels, if our observations will be further validated, NGAL urinary detection might be used as an additional tool in the pre-surgical definition of brain lesions involving difficult differential diagnosis
Correlative evidence that tumor cell-derived caveolin-1 mediates angiogenesis in meningiomas
No full textSince it has recently been reported that caveolin-1 (cav-1) may favor the progression of prostatic and renal cancers by stimulating tumor neoangiogenesis, we thought it of interest to analyze the correlation between cav-1 expression and tumor microvessel density (MVD) in meningiomas. In the present study we quantified cav-1 expression by immunohistochemistry and used CD105 immunohistochemical staining to measure MVD. Sixty-two formalin-fixed, paraffin-embedded, surgically resected meningiomas were submitted to the analysis. On the basis of cav-1 immuno-expression, cases were subdivided into meningiomas displaying a low (n = 34) and a high (n = 28) cav-1 immuno-expression, respectively. Mann-Whitney test showed that a significantly higher MVD was present in the cases with a high cav-1 expression than in those with a low expression (mean 24.44 vs. 41.28 microvessels/mm(2)) (P = 0.0001). Moreover, Spearman test revealed a significant positive correlation between cav-1 rate of expression and MVD counts in the meningiomas of our series (r = 0.390; P = 0.0023). Therefore, our study demonstrates the existence of an association between cav-1 expression and neoangiogenesis in meningiomas, suggesting that cav-1 may mediate the progression of these tumors by stimulating the angiogenic process. Besides, it is known that the progression of meningiomas is paralleled by an increase in MVD. The clarification of cav-1 role in the neoangiogensis of meningiomas may open new insights about the possibility of novel therapeutic strategies in these neoplasias
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