Project description:In our clinical practice, we perform genome-wide high-resolution SNP-array analysis as an adjunct to the histopathologic diagnosis for diagnostically challenging melanocytic tumors. The concept of using array-based DNA copy number analysis to screen for gene fusions associated with unbalanced genomic aberrations flanking the fusion points was applied in the diagnostic setting, and intragenic copy number changes involving common receptor kinase genes are typically further analyzed and, if necessary, studied by alternative methods. Here we present the discovery of recurrent NTRK3 gene rearrangements in childhood melanocytic neoplasms based on genome-wide high-resolution SNP-array analysis.
Project description:Retinoblastoma is a childhood retinal tumor that initiates in response to biallelic RB1 inactivation. We show that post-mitotic human cone precursors are uniquely sensitive to the oncogenic effects of Rb depletion. Rb knockdown induced cone precursor proliferation in prospectively isolated populations. SNP-array analysis of two Rb/p130-depleted cone precursor cell lines, revealing no megabase-size loss of heterozygosity (LOH) or copy number alterations (CNAs). SNP-array analysis of one Rb/p130-depleted (tumor 1) or one Rb-depleted (tumor 2) cone precursor-derived tumors, revealing no megabase-size LOH or CNAs, consistent with the lack of DNA copy number alterations in some retinoblastomas. Thus, the cone precursor tumors resembled human retinoblastomas at the molecular cytogenetic level. High resolution SNP-array DNA copy number analyses were performed using CytoScan® HD (Affymetrix, 901835) according to the manufacturer's directions. Data were analyzed using Chromosome Analysis Suite 2.0 (Affymetrix). DNA was extracted from two Rb/p130 depleted cone precursor cell lines and two cryopreserved mouse retinoblastoma samples from eyes xenograted with Rb/p130 or Rb depleted cone precursors. Affymetrix SNP analysis on retinoblastoma cell lines Y79, RB176, and WERI were used as control. Normal human genome 19 was used as reference.
Project description:SNP array data from 12 childhood adrenocortical tumors (ACT) were used to identify recurrent chromosome rearrangements and candidate driver genes.
Project description:Retinoblastoma is a childhood retinal tumor that initiates in response to biallelic RB1 inactivation. We show that post-mitotic human cone precursors are uniquely sensitive to the oncogenic effects of Rb depletion. Rb knockdown induced cone precursor proliferation in prospectively isolated populations. SNP-array analysis of two Rb/p130-depleted cone precursor cell lines, revealing no megabase-size loss of heterozygosity (LOH) or copy number alterations (CNAs). SNP-array analysis of one Rb/p130-depleted (tumor 1) or one Rb-depleted (tumor 2) cone precursor-derived tumors, revealing no megabase-size LOH or CNAs, consistent with the lack of DNA copy number alterations in some retinoblastomas. Thus, the cone precursor tumors resembled human retinoblastomas at the molecular cytogenetic level.
Project description:We performed whole genome single nucleotide polymorphism (SNP) based analysis of all available Venezuelan equine encephalitis (VEE) virus antigenic complex genomes and developed a high resolution genome-wide SNP microarray. We used the SNP microarray to analyze a broad panel of VEEV isolates, found excellent concordance between array and sequence based genotypes for previously sequenced strains, and genotyped unsequenced strains.
Project description:SNP array data from 13 Brazilian childhood adrenocortical tumors (ACTs) were analyzed to detect recurrent copy number changes and highlight potential candidate driver genes.
Project description:Purpose: To define copy number alterations and gene expression signatures underlying pediatric high-grade glioma (HGG). Patients and Methods: We conducted a high-resolution analysis of genomic imbalances in 78 de novo pediatric HGG, including 7 diffuse intrinsic pontine gliomas, and 10 HGG cases arising in children who received cranial irradiation for a previous cancer, using Affymetrix 500K GeneChips. Gene expression signatures for 53 tumors were analyzed with Affymetrix U133v2 arrays. Results were compared with publicly available data from adult tumors. Results: Pediatric and adult glioblastoma were clearly distinguished by frequent gain of chromosome 1q (30% vs 9%) and lower frequency of chromosome 7 gain (13% vs 74%), respectively. The most common focal amplifications also differed, with PDGFRA and EGFR predominant in childhood and adult populations respectively. These common alterations in pediatric HGG were detected at higher frequency in irradiation-induced tumors, suggesting that these are initiating events in childhood gliomagenesis. CDKN2A was the most common tumor suppressor gene targeted by homozygous deletion in pediatric HGG. No IDH1 hotspot mutations were found in pediatric tumors, highlighting molecular differences in pathogenesis between childhood HGG and adult secondary glioblastoma. Integrated copy number and gene expression data indicated that deregulated PDGFRA signaling plays a major role in pediatric HGG. Conclusions: Integrated molecular profiling showed substantial differences in the molecular features underlying pediatric and adult HGG, indicating that findings in adult tumors cannot be simply extrapolated to younger patients. PDGFRA may be a useful target for pediatric HGG including diffuse pontine gliomas. Keywords: disease state analysis 78 samples for SNP analysis, including 10 samples arising in children who received cranial irradiation for a previous cancer and 7 diffuse pontine gliomas; 53 of them with gene expression analysis; 2 tumor grades To have access to SNP CEL files, please contact Dr. Suzanne Baker (suzzane.baker@stjude.org).
Project description:Melanoma is the least common form of skin cancer, but accounts for the most deaths. Dermatopathologists face difficult diganostic determinations with a subset of ambiguous melanoma cases. Copy number variation in melanoma can serve as an additional biomarker to distinguish melanoma from benign melanocytic lesions.
Project description:SNP array data from 12 childhood adrenocortical tumors (ACT) were used to identify recurrent chromosome rearrangements and candidate driver genes. 12 childhood ACT were analyzed with Illumina Human610-Quad v1.0 BeadChips.