Project description:Distinguishing between Spitz nevus and melanoma presents a challenging task for clinicians and pathologists. Most of these lesions are submitted entirely in formalin for histologic analysis by conventional hematoxylin and eosin-stained sections, and fresh-frozen material for ancillary studies is rarely collected. Molecular techniques, such as comparative genomic hybridization (CGH), can detect chromosomal alterations in tumor DNA that differ between these 2 lesions. This study investigated the ability of high-resolution array-based CGH to serve as a diagnostic test in distinguishing Spitz nevus and melanoma using DNA isolated from formalin-fixed and paraffin-embedded samples. Two of 3 Spitz nevi exhibited no significant chromosomal alterations, while the third showed gain of the short arm of chromosome 11p. The latter finding has previously been described as characteristic of a subset of Spitz nevi. The 2 melanomas showed multiple copy number alterations characteristic of melanoma such as 1q amplification and chromosome 9 deletion. This study has shown the utility of array-based CGH as a potential molecular test in distinguishing Spitz nevus from melanoma. The assay is capable of using archival paraffin-embedded, formalin-fixed material; is technically easier to perform as compared with conventional CGH; is more sensitive than conventional CGH in being able to detect focal alterations; and can detect copy number alterations even with relatively small amounts of lesional tissue as is typical of many skin tumors. Series_type = clinical_history_design A clinical history design type is where the organisms clinical history of diagnosis, treatments, e.g. vaccinations, surgery etc. Keywords: other
Project description:A substantial part of cutaneous malignant melanomas develops from benign nevi. However, the precise molecular events driving the transformation from benign to malignant melanoma are not well understood. We used laser microdissection and mass spectrometry to analyze the proteomes of melanoma subtypes, including superficial spreading melanomas (SSM, n=17), nodular melanomas (NM, n=17), and acral melanomas (AM, n=15). Furthermore, we compared the proteomes of nevi cells and melanoma cells within the same specimens (nevus-associated melanoma (NAM, n=14)). In total, we quantified 7,935 proteins. Despite the genomic and clinical differences of the melanoma subtypes, our analysis revealed relatively similar proteomes, except for the upregulation of proteins involved in immune activation in NM vs AM. Examining NAM versus nevi, we found 1,725 differentially expressed proteins. Among these proteins were 140 that overlapped with cancer hallmarks, tumor suppressors, and regulators of metabolism and cell cycle. Pathway analysis indicated aberrant activation of the RAS/MAPK and PI3K-AKT-mTOR pathways, as well as the Hippo-YAP pathway. Using a classifier, we identified six proteins capable of distinguishing melanoma from nevi samples. Our study represents the first comprehensive comparative analysis of the proteome in melanoma subtypes and associated nevi, offering new insights into the biological behavior of these distinct entities.
Project description:The aim of this work was to identify the Copy Number Aberrations (CNAs) by high-resolution array Comparative Genomic Hybridization (aCGH) on 19 formalin-fixed, paraffin-embedded (FFPE) samples of treatment-naïve COM.
Project description:Analysis of DNA from 89 oral lesions by whole genome tiling-path array comparative genomic hybridization. Keywords: array comparative genomic hybridization Genomic DNA isolated from 89 formalin-fixed paraffin-embedded oral dysplasias and tumors, then profiled by whole genome tiling-path array CGH to identify DNA copy alterations for each case.
Project description:Dermatofibrosarcoma protuberans (DFSP) is an aggressive spindle cell neoplasm. It is associated with the chromosomal translocation, t(17:22), which fuses the COL1A1 and PDGFbeta genes. We determined the characteristic gene expression profile of DFSP and characterized DNA copy number changes in DFSP by array-based comparative genomic hybridization (array CGH). Fresh frozen and formalin-fixed, paraffin-embedded samples of DFSP were analyzed by array CGH (four cases) and DNA microarray analysis of global gene expression (nine cases). The nine DFSPs were readily distinguished from 27 other diverse soft tissue tumors based on their gene expression patterns. Genes characteristically expressed in the DFSPs included PDGFbeta and its receptor, PDGFRB, APOD, MEOX1, PLA2R, and PRKCA. Array CGH of DNA extracted either from frozen tumor samples or from paraffin blocks yielded equivalent results. Large areas of chromosomes 17q and 22q, bounded by COL1A1 and PDGFbeta, respectively, were amplified in DFSP. Expression of genes in the amplified regions was significantly elevated. Our data shows that: 1) DFSP has a distinctive gene expression profile; 2) array CGH can be applied successfully to frozen or formalin-fixed, paraffin-embedded tumor samples; 3) a characteristic amplification of sequences from chromosomes 17q and 22q, demarcated by the COL1A1 and PDGFbeta genes, respectively, was associated with elevated expression of the amplified genes. A disease state experiment design type is where the state of some disease such as infection, pathology, syndrome, etc is studied. Keywords: disease_state_design
Project description:Primary uveal melanomas show multiple chromosomal aberrations. To identify genome variation in six human primary uveal melanomas, genome wide copy number variation (CNV) analyses were carried out in human primary uveal melanoma samples using array comparative genome hybridization.
Project description:Genome wide DNA methylation profiling of 89 primary invasive FFPE melanomas and 73 nevi were evaluated using the Illumina Infinium HumanMethylation450 BeadChip array
Project description:Primary Central Nervous System Lymphomas. A validation study of array-based Comparative Genomic Hybridization in Formalin-Fixed Paraffin-Embedded Tumor Specimens
Project description:Dermatofibrosarcoma protuberans (DFSP) is an aggressive spindle cell neoplasm. It is associated with the chromosomal translocation, t(17:22), which fuses the COL1A1 and PDGFbeta genes. We determined the characteristic gene expression profile of DFSP and characterized DNA copy number changes in DFSP by array-based comparative genomic hybridization (array CGH). Fresh frozen and formalin-fixed, paraffin-embedded samples of DFSP were analyzed by array CGH (four cases) and DNA microarray analysis of global gene expression (nine cases). The nine DFSPs were readily distinguished from 27 other diverse soft tissue tumors based on their gene expression patterns. Genes characteristically expressed in the DFSPs included PDGFbeta and its receptor, PDGFRB, APOD, MEOX1, PLA2R, and PRKCA. Array CGH of DNA extracted either from frozen tumor samples or from paraffin blocks yielded equivalent results. Large areas of chromosomes 17q and 22q, bounded by COL1A1 and PDGFbeta, respectively, were amplified in DFSP. Expression of genes in the amplified regions was significantly elevated. Our data shows that: 1) DFSP has a distinctive gene expression profile; 2) array CGH can be applied successfully to frozen or formalin-fixed, paraffin-embedded tumor samples; 3) a characteristic amplification of sequences from chromosomes 17q and 22q, demarcated by the COL1A1 and PDGFbeta genes, respectively, was associated with elevated expression of the amplified genes.