Project description:The risk of developing cutaneous squamous cell carcinoma (SCC) is markedly increased in organ transplant recipients (OTRs) compared to the normal population. Next to sun exposure, the immunosuppressive regimen is an important risk factor for the development of SCC in OTRs. Various gene mutations (e.g. TP53) and genetic alterations (e.g. loss of CDKN2A, amplification of RAS) have been found in SCCs. The aim of this genome-wide study was to identify pathways that are consistently involved in the formation of SCCs and their precursor lesions, actinic keratoses (AKs). To perform the analysis in an isogenic background, RNA and DNA were isolated from normal (unexposed) epidermis, benign AK, and SCC from each of 15 OTRs. Hierarchical cluster analysis of mRNA expression profiles showed SCC, AK and epidermal samples to separate into three distinct groups. Several thousand genes were differentially expressed between epidermis, AK and SCC; most upregulated in SCCs were genes related to hyperproliferation and stress markers, such as keratin 6 (KRT6), KRT16 and KRT17. Matching to oncogenic pathways revealed activation of downstream targets of RAS and cMYC in SCCs and of NFkappaB and TNF already in AKs. Patients were selected from the group of OTRs that are regularly seen at the dermatology clinic of the Leiden University Medical Center. Patients with clinically suspected SCC were informed on the study and after informed consent was obtained, fresh frozen samples were obtained from SCCs (n=15), AKs (n=14) and NS (n=13). RNA was isolated and gene expression profiles were obtained using HumanWG-6 v2 Expression BeadChips (Illumina). The normalized expression data was analyzed for differences in expression between SCC, AK and NS, at single-gene level but also at geneset level.
Project description:The risk of developing cutaneous squamous cell carcinoma (SCC) is markedly increased in organ transplant recipients (OTRs) compared to the normal population. Next to sun exposure, the immunosuppressive regimen is an important risk factor for SCC development in OTRs. Various gene mutations (e.g. TP53) and genetic alterations (e.g. CDKN2A loss, RAS amplification) have been found in SCCs. The aim of this study was to identify genomic alterations that are consistently involved in the formation of SCCs and their precursor lesions, actinic keratoses (AKs). To perform the analysis in an isogenic background, DNA was isolated from SCC and AK from each of 13 OTRs. Tumor samples and their matching normal control (peripheral blood) were analyzed on the Illumina HumanHap550V3_duo genotyping beadchips. In contrast to previous studies, genome-wide SNP analysis showed very few copy number variations in AKs and SCCs, and these variations had no apparent relationship with observed changes in mRNA expression profiles (GSE32628). Other molecular mechanisms, such as DNA methylation or miRNA alterations, may affect gene expression in SCCs of OTRs. Patients were selected from the group of OTRs that are regularly seen at the dermatology clinic of the Leiden University Medical Center. Patients with clinically suspected SCC were informed on the study and after informed consent was obtained, fresh frozen samples were obtained from SCCs (n=15, including 2 repeats) and AKs (n=11). Peripheral blood was taken as normal control. DNA was isolated and SNP profiles were obtained using HumanHap550V3_duo Genotyping BeadChips (Illumina). Both the log R ratio and the B allele frequency (BAF) were investigated to identify copy number alterations and loss of heterozygosity (LOH) The tumor DNA samples are from the same tumor samples as the RNA samples in GSE32628.
Project description:The diagnosis of myelodysplastic syndromes (MDS) remains problematic due to the subjective nature of morphological assessment. The reported high frequency of somatic mutations and increased structural variants by array-based cytogenetics have provided potential objective markers of disease however this has been complicated by reports of similar abnormalities in the healthy population. We aimed to identify distinguishing features between those with early MDS and reported healthy individuals by characterising 69 patients who, following a non-diagnostic marrow, developed progressive dysplasia or acute myeloid leukaemia (AML). Targeted sequencing and array based cytogenetics identified a driver mutation and/or structural variant in 91% (63/69) of pre-diagnostic samples with the mutational spectrum mirroring that in the MDS population. When compared with the reported healthy population the mutations detected had significantly greater median variant allele fraction (40% vs 9-10%) and occurred more commonly with additional mutations (≥2 mutations 64% vs. 8%). Furthermore mutational analysis identified a high-risk group of patients with shorter time to disease progression and poorer overall survival. The mutational features in our cohort are distinct from those seen in the healthy population and, even in the absence of definitive disease, can predict outcome. Early detection may allow consideration of intervention in poor risk patients. We performed array based cytogenetics using HumanCytoSNP-12 (Illumina) on 69 patients diagnosed with acute myeloid leukaemia or myelodysplastic syndrome who had a previously non-diagnostic sample. SNP array analysis was performed on all diagnostic samples. In those with a documented abnormality, SNP-A was performed on the corresponding pre-diagnostic sample (n=32).
Project description:A genome-wide eQTL analysis was performed in whole blood samples collected from 76 Japanese subjects. RNA microarray analysis was performed for 3 independent samples that were genotyped in a genome-wide scan. The correlations between the genotypes of 534,404 autosomal single nucleotide polymorphisms (SNPs) and the expression levels of 30,465 probes were examined for each sample. The SNP-probe pairs with combined correlation coefficients of all 3 samples corresponding to P < 3.10 × 10-12 (i.e., Bonferroni-corrected P < 0.05) were considered significant. SNP-probe pairs with a high likelihood of cross-hybridization and SNP-in-probe effects were excluded to exclude false positive results. We identified 102 cis-acting and 5 trans-acting eQTL regions. The cis-eQTL regions were widely distributed both upstream and downstream of the gene, as well as within the gene. RNA microarray data obtained from 3 independent samples originally recruited for other studies investigating the gene expression levels in psychiatric disorders were used in the present study. For the purpose of the present analyses, genomic DNA was collected from 24 subjects (13 men and 11 women, mean age [SD] = 39.9 [7.6] years) in sample 1, 24 subjects in sample 2 (12 men and 12 women, 34.1 [11.5] years), and 28 subjects (14 men and 14 women, 41.4 [11.8] years) in sample 3. Some of the subjects had depressive symptoms, but all were physically healthy and without clinically significant systemic disease (e.g., malignant disease, diabetes mellitus, hypertension, renal failure, or endocrine disorders). Subjects were recruited from the outpatient clinic of the National Center of Neurology and Psychiatry Hospital, Tokyo, Japan, through advertisements in free local information magazines or through our website announcement. All the subjects were biologically unrelated Japanese individuals who resided in the same geographical area (western Tokyo). The study protocol was approved by the ethics committee at the National Center of Neurology and Psychiatry, Japan. Written informed consent was obtained from every subject after the study was explained to them. Venous blood was collected between 1100 and 1200 h in PAXgene tubes (Qiagen, Valencia) from each subject and was incubated at room temperature for 24 h for RNA stabilization. RNA was extracted from whole blood according to the manufacturer’s guidelines by using the PAXgene Blood RNA System Kit (PreAnalytix GmbH, Hombrechtikon, Switzerland). The RNA was quantified by optical density readings at A260nm by using the NanoDrop ND-1000 (Thermo Scientific, Rockford). Gene expression analysis was performed using Agilent Human Genome 4 × 44 K arrays (Agilent Technologies, Santa Clara). Raw signal data for each of the 3 independent samples were analyzed separately by the GeneSpring GX software (Agilent Technologies). Data were filtered according to the expression level for quality control to eliminate genes that were below the 20th percentile threshold. The expression value of each gene was normalized to the median expression value of all genes in each chip. A total of 30,465 probes were included in the analysis. Genomic DNA was obtained from venous blood samples. Genotyping was performed by Riken Genesis (Yokohama, Japan) using the Illumina HumanOmni1-Quad BeadChip (Illumina, Inc., San Diego). A total of 713,495 autosomal SNPs were assessed for quality using the PLINK v1.07 software. All SNPs with a call rate below 95%, a deviation from Hardy-Weinberg equilibrium at an error level of P < 0.001, or a minor allele frequency of less than 10% were excluded. The remaining 534,404 SNPs were used for further analysis.
Project description:Diamond Blackfan anemia is a congenital bone marrow failure syndrome characterized by hypoproliferative anemia, often with associated physical abnormalities. Perturbations of the ribosome appear critically important to the development of DBA, as alterations in 9 different ribosomal protein genes have been identified in multiple unrelated families, along with rarer abnormalities of additional ribosomal proteins. However, presently only 50-60% of patients have an identifiable genetic lesion by ribosomal protein gene sequencing. Using genome-wide SNP array to evaluate for regions of recurrent copy variation, we identified 2 patients with mosaic loss in the region of the the chromosome 5-deleted region involved in somatically-acquired 5q- myelodysplastic syndrome. Samples were analyzed on Illumina HumanOmni1_Quad, HumanOmniExpress, or HumanOmniExpressExome Genotyping bead arrays; 1 patient was available for longitudinal study including assessment of mosaicism in lymphoid and myeloid-enriched cell populations before treatement with lenolidamide. Similar studies were performed while on lenoldamide therapy in peripheral blood at 3 months and in bone marrow at 20 months of treatment. One patient with mosaic deletion of 5q was available for longitudinal study including assessment of gene expression in bone marrow before and during treatment with lenalidomide.
Project description:Induced pluripotent stem cells (iPSCs) have become an essential tool for both modeling how causal genetic variants impact cellular function in disease, as well as being an emerging source of tissue for transplantation medicine. Unfortunately the preparation of somatic cells, their reprogramming and the subsequent verification of iPSC pluripotency are laborious, manual processes that limit the scale and level of reproducibility of this technology. Here we describe a modular, robotic platform for iPSC reprogramming that enables automated, high-throughput conversion of skin biopsies into iPSCs and differentiated cells with minimal manual intervention. Using this platform, we demonstrate that automated reprogramming and the pooled selection of pluripotent cells results in high quality, stable, iPSCs. These lines display less line-to-line variation than either manually produced lines or lines produced through automation followed by single colony-subcloning. The robotic platform we describe will enable the application of iPSCs to population-scale biomedical problems including the study of complex genetic diseases and the development of personalized medicines. Two independent human fibroblast lines were reprogrammed, using modified mRNA, into induced pluripotent stem cells (iPSCs). The genomic stability of several cell lines was evaluated using SNP arrays. Three iPSCs originating from one fibroblast line were tested at passages 8 and 20, with two of these derived as picked (clonal) lines and the third being a pooled population. Five iPSCs originating from a second fibroblast line were tested at passages 8 and 20, with three of these derives derived as picked (clonal) lines and two derived as pooled populations. The iPSCs were compared against the original parental fibroblasts.
Project description:This dataset contains data from two acute myeloid leukaemia (AML) specimens processed with the Illumina CytoSNP-12 SNP array platform. SNP array data showed evidence of chromothripsis in these two specimens. Each deletion in the mosaic specimen was present in the same proportion of cells, which supports the view that the many breaks occur as a single event. Complementary FISH studies highlighted the inclusion of centromeres from different chromosomes during the formation of the new chromosomes. Residual bone marrow specimens were chosen from patients who were determined to have a complex karyotype which included abnormalities of chromosomes 5 and 17, by routine cytogenetic examination.
Project description:Parent-of-origin dependent expression of alleles, imprinting, has been suggested to impact a substantial proportion of mammalian genes. Its discovery requires allele-specific detection of expressed transcripts, but in some cases detected allelic expression (AE) bias has been interpreted as imprinting without demonstrating compatible transmission patterns and excluding heritable variation. Therefore, we utilized a genome-wide tool exploiting high density genotyping arrays in parallel measurements of genotypes in RNA and DNA to determine AE across the transcriptome in lymphoblastoid cell lines (LCLs) and skin fibroblasts derived from families. To investigate imprinting, transmission patterns were analyzed in 2 LCL trios, 1 LCL 3-generation pedigree and 9 FB trios. To investigate random monoallelic expression, 2 cell lines were treated with three concentrations of 5-azadeoxycytidine (AZA), and one cell line was treated for two time periods.
Project description:The Caucasus, inhabited by modern humans since the Early Upper Paleolithic and known for its linguistic diversity, is considered to be important for understanding human dispersals and genetic diversity in Eurasia. We report a synthesis of autosomal, Y chromosome, and mitochondrial DNA (mtDNA) variation in populations from all major subregions and linguistic phyla of the area. Autosomal genome variation in the Caucasus reveals significant genetic uniformity among its ethnically and linguistically diverse populations and is consistent with predominantly Near/Middle Eastern origin of the Caucasians, with minor external impacts. In contrast to autosomal and mtDNA variation, signals of regional Y chromosome founder effects distinguish the eastern from western North Caucasians. Genetic discontinuity between the North Caucasus and the East European Plain contrasts with continuity through Anatolia and the Balkans, suggesting major routes of ancient gene flows and admixture. 204 samples were analysed with the Illumina platform Human610-Quad v 1.0 and are described herein.