Search results for "Tissue microarray"
showing 10 items of 48 documents
Correlation between EGFR Amplification and the Expression of MicroRNA-200c in Primary Glioblastoma Multiforme
2014
Extensive infiltration of the surrounding healthy brain tissue is a critical feature in glioblastoma. Several miRNAs have been related to gliomagenesis, some of them related with the EGFR pathway. We have evaluated whole-genome miRNA expression profiling associated with different EGFR amplification patterns, studied by fluorescence in situ hybridization in tissue microarrays, of 30 cases of primary glioblastoma multiforme, whose clinicopathological and immunohistochemical features have also been analyzed. MicroRNA-200c showed a very significant difference between tumors having or not EGFR amplification. This microRNA plays an important role in epithelial-mesenchymal transition, but its impl…
The Role of Immunohistochemistry in Rhabdomyosarcoma Diagnosis Using Tissue Microarray Technology and a Xenograft Model
2015
Rhabdomyosarcomas (RMS) may resemble other non-myogenic sarcomas and malignant rhabdoid tumor (MRT). Alveolar rhabdomyosarcoma (ARMS) often harbors a typical translocation, but embryonal rhabdomyosarcoma (ERMS) lacks any specific rearrangement. Histopathology is not always sufficient for an unequivocal diagnosis, necessitating ancillary studies, including immunohistochemistry (IHC). Sixteen genetically tested RMS and two MRT were xenografted and followed in successive passages. Tissue microarrays were constructed including samples from original and xenograft tumors. Desmin, myogenin, CK, EMA, INI1, LSD1, AP2 beta, fibrillin-2, HMGA2, nestin, and SIRT1 were tested using immunohistochemical s…
Tissue microarrays: applications in study of p16 and p53 alterations in Ewing's cell lines
2008
Background Tissue microarrays (TMAs) are used to study genomics and proteomics in several tumour tissue samples. Cell lines (CC) are of great importance in the study of the genetic changes in tumours, and some reveal several aspects of tumour oncogenesis. There are few published reports on Ewing's tumours with TMAs including original tumours (OT) and corresponding CC. Methods We have performed four TMAs, from 3 OT and the corresponding CC of successive in vivo and in vitro tumour passages. Xenotransplant CC in nude mice from OT (XT/OT) was made. Subsequently multiple XT were performed and in vitro XT cell line (CC/XT) was obtained. In vivo re-inoculation of CC/XT (XT/CC) was planned. TMAs w…
A Comprehensive Tissue Microarray-Based FISH Screen of ALK Gene in Neuroblastomas
2011
The heterogeneity of neuroblastic tumors added to the immense biological complexity has led to an unprecedented scale of investigations and a growing list of molecular genetic targets for prognosis as well as therapy. Recently, Anaplastic Lymphoma Kinase (ALK) has been identified as a major predisposing gene as well as a potential therapeutic target for neuroblastoma. Individuals with ALK-related neuroblastoma susceptibility (i.e., heterozygous for an ALK mutation) are at risk of developing neuroblastic tumors. Aberrant copy number or mutations in ALK gene and overexpression of its protein tyrosine-kinase receptor have been related to poor prognosis of this disease, although a great degree …
Intracellular signalling via the AKT axis and downstream effectors is active and prognostically significant in cancer of unknown primary (CUP): a stu…
2012
Background: Hypothesising that cancer of unknown primary (CUP) may harbour unique characteristics, we present a translational study of the immunohistochemical expression and clinical correlation of key PTEN/AKT pathway molecules. Patients and methods: We collected 100 paraffin-embedded CUP tissue blocks. We studied using tissue microarrays the expression of PTEN, phospho-AKT, Cyclin D1, p21, phospho-RPS6. From the percentage of staining tumour cells and the literature, we selected cut-offs to classify the expression of each biomolecule. We correlated IHC expression with clinical data. Results: PTEN, pAKT, and pRPS6 showed frequent expression. At univariate analysis, high IHC expression of p…
Quantification of the heterogeneity of prognostic cellular biomarkers in ewing sarcoma using automated image and random survival forest analysis
2014
Driven by genomic somatic variation, tumour tissues are typically heterogeneous, yet unbiased quantitative methods are rarely used to analyse heterogeneity at the protein level. Motivated by this problem, we developed automated image segmentation of images of multiple biomarkers in Ewing sarcoma to generate distributions of biomarkers between and within tumour cells. We further integrate high dimensional data with patient clinical outcomes utilising random survival forest (RSF) machine learning. Using material from cohorts of genetically diagnosed Ewing sarcoma with EWSR1 chromosomal translocations, confocal images of tissue microarrays were segmented with level sets and watershed algorithm…
Immunohistochemical analysis of cancer-associated fibroblasts and podoplanin in head and neck cancer
2019
Background To immunohistochemically evaluate the association between the presence of cancer-associated fibroblasts (CAFs) and the tumour expression of podoplanin (PDPN) in head and neck squamous cell carcinoma (HNSCC) and their association with clinicopathological variables. Material and Methods A tissue microarray (TMA) with biopsy sections from patients diagnosed with HNSCC was stained with antibodies against the CAFs marker, α-smooth muscle actin (α-SMA), and PDPN. We subsequently evaluated their expression to determine the association between them and with clinicopathological variables including age, primary tumour site, TNM stage, and tumour differentiation grade. Results Positive reac…
Immunoreactivity using anti-ERG monoclonal antibodies in sarcomas is influenced by clone selection.
2014
The aim of the present study was to explore ERG immunoreactivity in a series of sarcomas, GIST and malignant rhabdoid tumor (MRT), considering the not fully elucidated specificity and sensitivity of this antibody. Paraffin-embedded tissue microarrays from those tumors were stained with anti-ERG against the C-terminus [(EPR3864(2)] and N-terminus (Clone 9FY). EPR3864(2) was positive in almost all angiosarcomas, and MRT.GIST were positive in a large proportion of cases (38.4%), and more than half the synovial sarcomas (52.7%) revealed EPR3864(2) staining. Several chondrosarcomas, osteosarcomas, rhabdomyosarcoma and Ewing's sarcoma family of tumors (ESFT) presented EPR3864(2) expression in a l…
Tissue microarray construction for salivary gland tumors study
2012
Objective: To describe and discuss the design, building and usefulness of tissue microarray (TMA) blocks for the study of salivary gland tumors (SGTs). Study Design: Two hundred thirty-eight formalin-fixed, paraffin-embedded SGTs were arranged in blocks of TMA using a manual tissue arrayer. Three representative cores of 1.0, 2.0 or 3.0mm were taken from each original block and their characteristics were analyzed and described. Results: It was created 12 TMA blocks that presented highly representative neoplastic cylinders. However, those neoplasias rich in cystic spaces such as mucoepidermoid carcinoma and Warthin tumor presented more difficulties to be sampled, as the neoplastic tissue avai…
Models of Biobanking and Tissue Preservation: RNA Quality in Archival Samples in Pathology Laboratories and “In Vivo Biobanking” by Tumor Xenografts …
2011
Tissue banks represent essential resources and platforms for biomedical research serving basic, translational, and clinical research projects. In this article, we describe 2 models of biobanking and tissue preservation with different approaches and aims. Archive tissue biobanking is described here as a resource of residual pathology tissues for translational research, which represents the huge clinical heterogeneity. In this context, managing of tissues and RNA quality in archive tissue are discussed. The other model of tissue biobanking is referred to as xenograft tissue banking, which represents an alternative method for obtaining large amounts of tissue, over an indefinite period, in so …