Project description:Osteosarcoma is an aggressive tumor of the bone that primarily affects young adults and adolescents. Osteosarcoma is characterized by genomic chaos and heterogeneity. While inactivation of tumor suppressor p53 TP53 is nearly universal other high frequency mutations or structural variations have not been identified. Despite this genomic heterogeneity, key conserved transcriptional programs associated with survival have been identified across human, canine and induced murine osteosarcoma. The epigenomic landscape, including DNA methylation, plays a key role in establishing transcriptional programs in all cell types. The role of epigenetic dysregulation has been studied in a variety of cancers but has yet to be explored at scale in osteosarcoma. Here we examined genome-wide DNA methylation patterns in 24 human and 44 canine osteosarcoma samples identifying groups of highly correlated DNA methylation marks in human and canine osteosarcoma samples. We also link specific DNA methylation patterns to key transcriptional programs in both human and canine osteosarcoma. Building on previous work, we built a DNA methylation-based measure for the presence and abundance of various immune cell types in osteosarcoma. Finally, we determined that the underlying state of the tumor, and not changes in cell composition, were the main driver of differences in DNA methylation across the human and canine samples. Significance: This is the first large scale study of DNA methylation in osteosarcoma and lays the ground work for the exploration of DNA methylation programs that help establish conserved transcriptional programs in the context of different genomic landscapes.
Project description:Osteosarcoma is the most common primary bone cancer in children, adolescents and young adults. It is a rare cancer type. To obtain a comprehensive view of protein expression in osteosarcoma, quantitative TMT–MS was performed with six pairs of osteosarcoma specimens and adjacent normal tissue.
Project description:Osteosarcoma is a malignancy with variable outcomes that are not tightly aligned with chemotherapy response. Previous work has suggested a possible role for microRNAs (miRNAs) in determining the susceptibility of osteosarcomas to treatment but formal miRNA-based outcome models have not been reported. Formalin-fixed, paraffin-embedded (FFPE) specimens may be a unique approach for such studies in a rare malignancy. We used supervised principal components analysis and logistic regression to study survival and chemoresponse endpoints, and miRNA activity and gene set analysis algorithms to study miRNA regulatory networks using mRNA data. Our study also creates a paradigm for FFPE-based miRNA clinical biomarker research in rare tumors.
Project description:Osteosarcoma (OS) is a very aggressive bone tumor characterized by highly abnormal complex karyotypes.This a-CGH is a part of an expriment whose aim was to identify, genomic imbalance, DNA methylation and gene expression profiles in a panel osteosarcoma tumors. Keywords: comparative genomic hybridization
Project description:Osteosarcoma is a malignancy with variable outcomes that are not tightly aligned with chemotherapy response. Previous work has suggested a possible role for microRNAs (miRNAs) in determining the susceptibility of osteosarcomas to treatment but formal miRNA-based outcome models have not been reported. Formalin-fixed, paraffin-embedded (FFPE) specimens may be a unique approach for such studies in a rare malignancy. We used supervised principal components analysis and logistic regression to study survival and chemoresponse endpoints, and miRNA activity and gene set analysis algorithms to study miRNA regulatory networks using mRNA data. Our study also creates a paradigm for FFPE-based miRNA clinical biomarker research in rare tumors.
Project description:Pulmonary metastasis continues to be the most common cause of death in osteosarcoma. Indeed, the 5-year survival for newly diagnosed osteosarcoma patients has not significantly changed in over 20 years. Further understanding of the mechanisms of metastasis and resistance for this aggressive pediatric cancer is necessary. Pet dogs naturally develop osteosarcoma providing a novel opportunity to model metastasis development and progression. Given the accelerated biology of canine osteosarcoma, we hypothesized that a direct comparison of canine and pediatric osteosarcoma expression profiles may help identify novel metastasis-associated tumor targets that have been missed through the study of the human cancer alone. Collectively, these data support the strong similarities between human and canine osteosarcoma and underline the opportunities provided by a comparative oncology approach as a means to improve our understanding of cancer biology and therapy.
Project description:Pulmonary metastasis continues to be the most common cause of death in osteosarcoma. Indeed, the 5-year survival for newly diagnosed osteosarcoma patients has not significantly changed in over 20 years. Further understanding of the mechanisms of metastasis and resistance for this aggressive pediatric cancer is necessary. Pet dogs naturally develop osteosarcoma providing a novel opportunity to model metastasis development and progression. Given the accelerated biology of canine osteosarcoma, we hypothesized that a direct comparison of canine and pediatric osteosarcoma expression profiles may help identify novel metastasis-associated tumor targets that have been missed through the study of the human cancer alone. Collectively, these data support the strong similarities between human and canine osteosarcoma and underline the opportunities provided by a comparative oncology approach as a means to improve our understanding of cancer biology and therapy.
Project description:Osteosarcoma (OS)is a rare primary malignant bone tumor in adolescents and children with a poor prognosis. Identification of prognostic genes lags far behind the advance of the treatments. We identified differential genes by microarray analysis from paired OS tissues. Hub genes, gene set enrichment analysis, and pathway analysis were performed to gain an insight into the pathway alterations of OS. These results showed CPE could be served as a prognostic factor in osteoblastic OS and should be further investigated as potential therapeutic target. The present study evaluated the whole transcriptome expression of osteosarcoma progression and provided novel therapeutic targets for advanced osteosarcoma.
Project description:Despite the development of diagnostic and advanced treatment strategies, the prognosis of patients with osteosarcoma remains poor. A limited understanding of the pathogenesis of osteosarcomas has impeded any improvement in patient outcomes over the past 4 decades. It is thus urgent to identify novel effective targets and treatment regimens for osteosarcoma patients. In this study we delineated the super-enhancer landscape in osteosarcoma cells on the basis of H3K27ac signal intensity by ChIP-Seq and found that super-enhancer-associated genes contribute to the malignant potential of osteosarcoma. THZ2, a novel small molecular inhibitor, shows a powerful anti-osteosarcoma ability through suppress super-enhancer-associated genes selectively. Utilizing the characteristics of super-enhancers in cancer cells, we identified 5 critical super-enhancer-associated oncogenes. With the comparative and retrospective analysis in large numbers of human specimens from patients, these 5 oncogenes were observed closely related with patient prognosis. Our findings determined that targeting super-enhancer-associated oncogenes with transcriptional inhibitor, THZ2, was a promising therapeutic strategy in osteosarcoma, and provided novel candidate targets for patients with osteosarcoma.
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.