0000000000824628
AUTHOR
Ola Myklebost
Preclinical xenograft models of human sarcoma show nonrandom loss of aberrations
BACKGROUND: Human tumors transplanted into immunodeficient mice (xenografts) are good preclinical models, and it is important to identify possible systematic changes during establishment and passaging in mice. METHODS: High-resolution microarray-based comparative genomic hybridization (array CGH) was used to investigate how well a series of sarcoma xenografts, including 9 patient/xenograft pairs and 8 early versus late xenograft passage pairs, represented the patient tumor from which they originated. RESULTS: In all analyses, the xenografts were more similar to their tumor of origin than other xenografts of the same type. Most changes in aberration patterns were toward a more normal genome …
miR-486-5p expression is regulated by DNA methylation in osteosarcoma.
Abstract Background Osteosarcoma is the most common primary malignant tumour of bone occurring in children and young adolescents and is characterised by complex genetic and epigenetic changes. The miRNA miR-486-5p has been shown to be downregulated in osteosarcoma and in cancer in general. Results To investigate if the mir-486 locus is epigenetically regulated, we integrated DNA methylation and miR-486-5p expression data using cohorts of osteosarcoma cell lines and patient samples. A CpG island in the promoter of the ANK1 host gene of mir-486 was shown to be highly methylated in osteosarcoma cell lines as determined by methylation-specific PCR and direct bisulfite sequencing. High methylati…
mRNA expression profiles of primary high-grade central osteosarcoma are preserved in cell lines and xenografts
Abstract Background Conventional high-grade osteosarcoma is a primary malignant bone tumor, which is most prevalent in adolescence. Survival rates of osteosarcoma patients have not improved significantly in the last 25 years. Aiming to increase this survival rate, a variety of model systems are used to study osteosarcomagenesis and to test new therapeutic agents. Such model systems are typically generated from an osteosarcoma primary tumor, but undergo many changes due to culturing or interactions with a different host species, which may result in differences in gene expression between primary tumor cells, and tumor cells from the model system. We aimed to investigate whether gene expressio…
Additional file 1 of miR-486-5p expression is regulated by DNA methylation in osteosarcoma
Additional file 1: Supplementary Table S1. Overview of TaqMan assays for miRNA and mRNA qRT-PCR experiments. Supplementary Table S2. Primers used for qualitative Methylation-Specific Polymerase Chain Reaction (MSP), bisulfite sequencing (BS) and quantitative Methylation-Specific Polymerase Chain Reaction (qMSP). Supplementary Figure S1. Genomic overview of the mir-486/ANK1 locus. Supplementary Figure S2. Expression of ANK1 transcript variants in untreated and 5-Aza treated osteosarcoma cell lines. Supplementary Figure S3. Methylation level of miR-486 as assessed by methylation specific PCR (MSP).
A tissue microarray study of osteosarcoma: histopathologic and immunohistochemical validation of xenotransplanted tumors as preclinical models.
Osteosarcomas (OS) are aggressive neoplasms with a wide range of morphologic patterns.OS cases (primary and xenotransplanted) with paraffin blocks available were collected and included in tissue microarrays (TMAs). A morphologic evaluation including the different passages in mice was carried out according to the new WHO criteria. In addition, TMAs were analyzed with a wide panel of immunohistochemical (IHC) markers (osteonectin, osteocalcin,cytokeratin, S100, Sox-9, Ki-67, Bcl-2, p53, p16, survivin, CD99, and caveolin-1).A total of 61 cases were collected. The distribution of the cases according to the histopathologic pattern was: 38 osteogenic OS, 8 primary chondrogenic OS, 2 primary telan…