Project description:Gain or loss of genes and deregulation of gene expression can result in cumulative and progressive disruptions of normal cellular functions. Cancer-specific changes in gene expression play an essential role in cancer occurrence, and ultimately lead to cancer-related self-sufficiency in growth signals, insensitivity to growth inhibitory signals, evasion of apoptosis, limitless replicative potential, angiogenesis, and metastasis. We aimed to analyse such changes in gene expression related to osteosarcoma. Keywords: Comparative We performed genome-wide comparison of gene expression and identified genes that are differentialy expressed in osteosarcoma (U2OS, MG63) cell lines relative to normal human osteoblasts (HOB)
Project description:Osteosarcomas are the most common primary malignant tumours of bone, and almost all conventional osteosarcomas are high-grade tumours showing complex genomic aberrations. We have integrated genome-wide genetic and epigenetic profiles from the EuroBoNeT panel of 19 human osteosarcoma cell lines based on microarray technologies. The cell lines showed complex patterns of DNA copy number changes, where copy number gains were significantly associated with gene-rich regions of the genome and losses with gene-poor areas. Integration of the datasets showed that the mRNA levels were regulated by either alterations in DNA copy number or DNA methylation. Using a recurrence threshold of 6/19 (> 30 %) cell lines, 348 genes were identified as having alterations of two data types (gain or hypo-methylation/over-expression, loss or hyper-methylation/under-expression). These genes are involved in embryonic skeletal system development and morphogenesis, as well as remodelling of extracellular matrix. Several genes were hyper-methylated and under-expressed compared to normal osteoblasts, and expression could be reactivated by demethylation using 5-Aza-2M-bM-^@M-^Y-deoxycytidine treatment for all four genes tested. Globally, there was as expected a significant positive association between gain and over-expression, loss and under-expression as well as hyper-methylation and under-expression, but gain was also associated with hyper-methylation and under-expression, suggesting that hyper-methylation may oppose the effects of increased copy number for some genes. Integrative analysis of genome-wide genetic and epigenetic alterations identified mechanistic dependencies and relationships between DNA copy number and DNA methylation in terms of regulating mRNA expression levels in osteosarcomas, contributing to better understanding of osteosarcoma biology. Comparison of DNA methylation patterns in 19 osteosarcoma cell lines and 6 normal samples (osteoblasts and bones)
Project description:Osteosarcomas are the most common primary malignant tumours of bone, and almost all conventional osteosarcomas are high-grade tumours showing complex genomic aberrations. We have integrated genome-wide genetic and epigenetic profiles from the EuroBoNeT panel of 19 human osteosarcoma cell lines based on microarray technologies. The cell lines showed complex patterns of DNA copy number changes, where copy number gains were significantly associated with gene-rich regions of the genome and losses with gene-poor areas. Integration of the datasets showed that the mRNA levels were regulated by either alterations in DNA copy number or DNA methylation. Using a recurrence threshold of 6/19 (> 30 %) cell lines, 348 genes were identified as having alterations of two data types (gain or hypo-methylation/over-expression, loss or hyper-methylation/under-expression). These genes are involved in embryonic skeletal system development and morphogenesis, as well as remodelling of extracellular matrix. Several genes were hyper-methylated and under-expressed compared to normal osteoblasts, and expression could be reactivated by demethylation using 5-Aza-2M-bM-^@M-^Y-deoxycytidine treatment for all four genes tested. Globally, there was as expected a significant positive association between gain and over-expression, loss and under-expression as well as hyper-methylation and under-expression, but gain was also associated with hyper-methylation and under-expression, suggesting that hyper-methylation may oppose the effects of increased copy number for some genes. Integrative analysis of genome-wide genetic and epigenetic alterations identified mechanistic dependencies and relationships between DNA copy number and DNA methylation in terms of regulating mRNA expression levels in osteosarcomas, contributing to better understanding of osteosarcoma biology. Comparison of gene expression patterns in 19 osteosarcoma cell lines and 6 normal samples (osteoblasts and bones)
Project description:We performed genome-wide gene expression data of high-grade osteosarcoma cell lines, as well as on mesenchymal stem cells, and osteoblasts, and performed global test analysis in order to determine the most significantly affected KEGG pathways. Genome-wide gene expression analysis was performed on 19 high-grade osteosarcoma cell lines. Significantly differentially expressed genes were determined between osteosarcoma cells and two different sets of control samples - osteoblasts [n=3, GEO accession number GSE33382] and mesenchymal stem cells [n=12, GEO accession number GSE28974]. Global test was applied to the different analyses, in order to determine the most affected signaling pathways in osteosarcoma cells.
Project description:Patient-derived bone tumor (osteosarcoma and giant cell tumor of bone) cells, and the normal mesenchymal stem cells and osteoblasts were cultured and subjected to UV crosslinking (UV) at 254 nm or without crosslinking (noUV) as negative controls. Subsequently, RNA-binding proteins (RBPs) were identified by eRIC.
Project description:expression analysis from a genetically engineered mouse model of osteosarcoma; determine the expression profile of mouse osteosarcoma Experiment Overall Design: 3 control in vitro differentiated WT primary osteoblasts; 15 primary osteosarcoma; 4 OS cell lines; 4 secondary tumours
Project description:Background: Osteosarcomas are the most common primary malignant tumors of bone and show multiple and complex genomic aberrations. miRNAs are non-coding RNAs capable of regulating gene expression at the post transcriptional level, and miRNAs and their target genes may represent novel therapeutic targets or biomarkers for osteosarcoma. In order to investigate the involvement of miRNAs in osteosarcoma development, global microarray analyses of a panel of 19 human osteosarcoma cell lines was performed. Principal findings: We identified 177 miRNAs that were differentially expressed in osteosarcoma cell lines relative to normal bone. Among these, miR-126/miR-126*, miR-142-3p, miR-150, miR-223, miR-486-5p and members of the miR-1/miR-133a, miR-144/miR-451, miR-195/miR-497, and miR-206/miR-133b clusters were found to be downregulated in osteosarcoma cell lines. All miRNAs in the paralogous clusters miR-17-92, miR-106b-25 and miR-106a-92 were overexpressed. Furthermore, the upregulated miRNAs included miR-9/miR-9*, miR-21*, miR-31/miR-31*, miR-196a/miR-196b, miR-374a and members of the miR-29, miR-130/301 families. The most interesting inversely correlated miRNA/mRNA pairs in osteosarcoma cell lines included miR-9/TGFBR2 and miR-29/the p85α regulatory subunit of PI3K. PTEN mRNA correlated inversely with miR-92a and members of the miR-17 and miR-130/301 families. Expression profiles of selected miRNAs were confirmed in clinical samples. A set of miRNAs, miR-1, miR-18a, miR-18b, miR-19b, miR-31, miR-126, miR-142-3p, miR-133b, miR-144, miR-195, miR-223, miR-451 and miR-497 was identified with an intermediate expression level in osteosarcoma clinical samples compared to osteoblasts and bone, which may reflect the differentiation level of osteosarcoma relative to the undifferentiated osteoblast and fully differentiated normal bone. Significance: This study provides an integrated analysis of miRNA and mRNA in osteosarcoma, and gives new insight into the complex genetic mechanisms of osteosarcoma development and progression.
Project description:Gain or loss of genes and deregulation of gene expression can result in cumulative and progressive disruptions of normal cellular functions. Cancer-specific changes in gene expression play an essential role in cancer occurrence, and ultimately lead to cancer-related self-sufficiency in growth signals, insensitivity to growth inhibitory signals, evasion of apoptosis, limitless replicative potential, angiogenesis, and metastasis. We aimed to analyse such changes in gene expression related to osteosarcoma. We performed genome-wide comparison of gene expression and identified genes that are differentialy expressed in osteosarcoma tumour samples relative to normal human osteoblasts (HOB)
Project description:We studied MET-transformed human primary osteoblasts (MET-HOBs), which we previously turned into osteosarcoma cells by LV driven over-expression of MET oncogene. We obtained distinct MET transformed HOB clones derived from independent events of transgene integration. To characterise the phenotype of the MET-HOB clones we used oligonucleotide microarrays. Expression profiles of MET-HOBs and osteosarcoma cell lines were compared.