Project description:Serous borderline tumours (SBOT) are a challenging group of ovarian tumours positioned between benign and malignant disease. We have profiled the DNA methylomes of 12 low grade serous carcinoma (LGSC), 19 SBOT and 16 benign serous tumours (BST) across 27,578 CpG sites to further characterise the epigenomic relationship between these subtypes of ovarian tumours. Unsupervised hierarchical clustering of DNA methylation levels showed that LGSC differ distinctly from BST, however, not from SBOT. Gene ontology analysis of genes showing differential methylation at linked CpG sites between LGSC and BST revealed significant enrichment of gene groups associated with cell adhesion, cell-cell signalling and the extracellular region consistent with a more invasive phenotype of LGSC as compared to BST. Consensus clustering highlighted differences between SBOT methylomes and returned subgroups with malignant-like or benign-like methylation profiles. Furthermore, a two loci DNA methylation signature can distinguish between these SBOT subgroups with benign-like and malignant-like methylation characteristics. Our findings indicate striking similarities between SBOT and LGSC methylomes which supports a common origin and the view that LGSC may arise from SBOT. A subgroup of SBOT can be classified into tumours with a benign-like or a malignant-like methylation profile which may help in identifying tumours more likely to progress into LGSC.
Project description:Serous borderline tumours (SBOT) are a challenging group of ovarian tumours positioned between benign and malignant disease. We have profiled the DNA methylomes of 12 low grade serous carcinoma (LGSC), 19 SBOT and 16 benign serous tumours (BST) across 27,578 CpG sites to further characterise the epigenomic relationship between these subtypes of ovarian tumours. Unsupervised hierarchical clustering of DNA methylation levels showed that LGSC differ distinctly from BST, however, not from SBOT. Gene ontology analysis of genes showing differential methylation at linked CpG sites between LGSC and BST revealed significant enrichment of gene groups associated with cell adhesion, cell-cell signalling and the extracellular region consistent with a more invasive phenotype of LGSC as compared to BST. Consensus clustering highlighted differences between SBOT methylomes and returned subgroups with malignant-like or benign-like methylation profiles. Furthermore, a two loci DNA methylation signature can distinguish between these SBOT subgroups with benign-like and malignant-like methylation characteristics. Our findings indicate striking similarities between SBOT and LGSC methylomes which supports a common origin and the view that LGSC may arise from SBOT. A subgroup of SBOT can be classified into tumours with a benign-like or a malignant-like methylation profile which may help in identifying tumours more likely to progress into LGSC. Array-based methylation profiling was performed using the Infinium HumanMethylation27 BeadChip in 12 low grade serous carcinoma, 19 serous borderline tumours and 16 benign serous tumours. The reproducibility of the Infinium HumanMethylation27 BeadChips was evaluated using four biological replicates of the high grade serous ovarian cancer cell line PEO1. Differential methylation cutoff was estimated from four biological replicates by bootstrap resampling and set at Δβ ≥ 0.25 corresponding to a FDR ≤ 0.09.
Project description:Genome wide DNA methylation profiling was done on expressed prostatic secretions (EPS) of normal individuals and dry-core needle biopsy samples of benign and malignant (Primary tumor) prostatic lesions. The Illumina Infinium 850k Infinium MethylationEPIC v 1.0 was used to obtain DNA methylation profiles across approximately 850,000 CpGs in EPS and prostatic lesion biopsy samples. Samples included 4 EPS of normal individuals, and 8 biopsy tissues of benign, and malignant lesions each of patient individuals.
Project description:Pheochromocytomas and paragangliomas (PPGL) are rare neuroendocrine, usually benign tumors. Currently, for these neoplasms the only reliable criterion of malignancy is the presence of metastases. The aim of the present study was to identify molecular markers that can distinguish malignant from benign PPGL. An mRNA expression array was performed on 40 benign and 11 malignant PPGL. Genes showing a significantly different expression between benign and malignant PPGL with a ratio ? 4 were selected. Differentially expressed genes were confirmed by qRT-PCR and subsequently tested in an independent validation series (4 benign and 4 malignant) by qRT-PCR. Finally, immunohistochemistry was performed for the validated genes on Tissue Micro Arrays, which included 100 PPGL (87 benign and 13 malignant). Ten genes, which were significantly differentially expressed between benign and malignant tumors (False Discovery Rates <0.05), were selected from the mRNA expression array data. Differential expression of Interleukin 13 Receptor Alpha 2 and Contactin 4 was confirmed (p<0.05) and validated by qRT-PCR. However, at the protein level, only Contactin 4 appeared to be significantly overexpressed in malignant tumors (58% in malignant versus 17% in benign; p<0.05). No difference in the immunohistochemical staining for Interleukin 13 Receptor Alpha 2 was observed between benign and malignant PPGL. Contactin 4 expression appears to be associated with malignancy in pheochromocytomas and paragangliomas, and may be predictive of malignant behavior.
Project description:Salivary gland myoepithelial tumors are relatively uncommon tumors with an unpredictable clinical course. More knowledge about their genetic profiles is necessary to identify novel predictors of disease. In this study, we subjected 27 primary tumors (15 myoepitheliomas and 12 myoepithelial carcinomas) to genome-wide microarray-based comparative genomic hybridization (array CGH). We set out to delineate known chromosomal aberrations in more detail and to unravel chromosomal differences between benign myoepitheliomas and myoepithelial carcinomas. Patterns of DNA copy number aberrations were analyzed by unsupervised hierarchical cluster analysis. Both benign and malignant tumors revealed a limited amount of chromosomal alterations (median of 5 and 7.5 respectively). In both tumor groups, high frequency gains (≥20%) were found mainly at loci of growth factors and growth factor receptors (e.g. PDGF, FGF(R)s, and EGFR). In myoepitheliomas, high frequency losses (≥20%) were detected at regions of proto-cadherins. Cluster analysis of the array CGH data identified three clusters. Differential copy numbers on chromosome arm 8q and chromosome 17 set the clusters apart. Cluster 1 contained a mixture of the two phenotypes (n=10), cluster 2 included mostly benign tumors (n=10), and cluster 3 only contained carcinomas (n=7). Supervised analysis between malignant and benign tumors revealed a 36 Mbp-region at 8q being more frequently gained in malignant tumors (p=0.007, FDR=0.05). This is the first study investigating genomic differences between benign and malignant myoepithelial tumors of the salivary glands at a genomic level. Both unsupervised and supervised analysis of the genomic profiles revealed chromosome arm 8q to be involved in the malignant phenotype of salivary gland myoepitheliomas.
Project description:Intra-tumor heterogeneity (ITH) has been studied at the morphologic, genomic, and transcriptomic level, but not proteomic level. Recent advances in mass spectrometric (MS) proteome quantification techniques, exemplified by SWATH-MS, a massively parallel targeting method, now also support precise quantitative proteomic comparisons across multiple samples, thus identifying molecular and implied functional differences. Here we used SWATH-MS to analyze the proteome profiles of a set of fresh-frozen prostate tissue samples derived from radical prostatectomy specimens. A high confidence set of 1,906 proteins were consistently quantified across 60 biopsy-level tissue samples from three prostatectomy patients, each consisting of 1.0 mm punch biopsies from histologically malignant (acinar and ductal adenocarcinoma) and matching benign prostatic hyperplasia tissues. The quantitative protein profiles allowed independent quantification of the degree of intra-tumor heterogeneity for each protein in benign and malignant tissues. We found that while majority of the proteins showed comparably low intra-tumor variability, 122 proteins were highly variable in malignant and/or matching benign tissues. We observed that proteins that varied between patients or tissue types also tended to be highly variable within prostate tissues, suggesting that these variability patterns will be a critical selection criterion in future protein biomarker studies. The data also permitted investigation of the heterogeneity of multiple biochemical pathways. The high variability of several of the pathways, including Glypican-1 network, alpha-linolenic acid metabolism and celecoxib pathway, explained contradictory results regarding them in the literature. In conclusion, we demonstrated a methodology for investigating proteomic intra-tumor heterogeneity from biopsy-level tissue samples, and quantified the degree of intra-tumor heterogeneity of 1,906 proteins in prostate tumors. The method and data presented here have advanced our understanding of tumor biology and offered critical insights for future biomarker development.
Project description:Perturbations in microRNA (miRNA) expression profiles has been reported for cutaneous malignant melanoma (CMM). With regards to a rapidly growing number of newly discovered miRNA sequences, the availability of up-to-date miRNA expression profiles for primary cutaneous malignant melanoma (PCMM), cutaneous malignant melanoma metastases (CMMM) and benign melanocytic naevi (BMN) is limited. Patients with PCMM (n=9), CMMM (n=4) and BMN (n=8) were included in the study. Specimens were obtained during surgery from the center of the tumors (lesional). An exploratory microarray analysis was performed by miRNA expression profiling based on miRBase V.16. Additionally, the expression levels of selected miRNA candidates were confirmed by TaqMan real-time quantitative polymerase chain reaction (RT-PCR). New miRNA candidates previously not described to be associated with CMM were found to be potentially dysregulated in CMM.
Project description:To investigate the pathogenesis of malignant phyllodes tumors of the breast, we used lncRNA+mRNA microarray expression profiling as a platform to investigate lncRNAs that play a key role in the malignant progression of phyllodes tumors of the breast.A total of 4 cases of breast fibroadenomas, 6 cases of benign phyllodes tumors and 6 cases of malignant phyllodes tumors were included. Fibroadenomas and benign phyllodes tumors were used as controls to screen out significantly differentially expressed lncrnas in malignant phyllodes tumors.