Project description:Genome wide DNA methylation profiling of dedifferentiated chondrosarcoma samples. Genomic DNA was extracted from formalin-fixed paraffin-embedded (FFPE) tissue after manual macrodissection to ensure at least 10% tumor content, followed by bisulfite converstion. All samples were processed on the Infinium 850k array and scanned using the Illumina iScan, according to the manufacturer's recommended protocol.
Project description:To examine methylation levels of genes, we performed whole-genome bisulfite sequence for 2 cell lines: NDCS-1, which was established from dedifferentiated chondrosarcoma and had a fast-growing phenotype, and OUMS-27, which was established from conventional chondrosarcoma and had a slow-growing phenotype.
Project description:Chondrosarcomas are malignant cartilage-forming bone tumours with heterogeneous behaviour, making prognostication and clinical management challenging. Histological grading is the primary tool for predicting clinical outcomes in conventional chondrosarcoma. However, its high interobserver variability limits reliable distinction between low- and high-risk patients, potentially leading to suboptimal clinical management. Given the increasing use of DNA methylation profiling as a valuable tool in surgical pathology for tumour classification, we investigated its prognostic value in central conventional chondrosarcoma. We generated methylation data from 69 primary central conventional chondrosarcomas profiled with Illumina’s Human MethylationEPIC Array (850k sites), and identified methylation sites individually linked to patient outcome. A LASSO Cox regression model was applied to these methylation sites to identify an optimal set of 8 informative sites. With the regression coefficients of these methylation sites, we constructed a risk score that predicts central conventional CHondrosarcoma Risk Outcome from Methylation (CHROME). CHROME stratifies patients into High or Low risk groups for disease recurrence, onset of metastasis and disease-specific mortality. Survival analysis in an independent validation cohort (n=68) demonstrated strong discriminatory performance of CHROME, with complete separation of outcomes and no adverse events observed in the Low risk group. Overview of the clinico-pathological information showed that a low grade (ACT/G1) case with an event was correctly assigned to the High risk group, while 9 high grade cases without events were classified as Low risk. CHROME provides accurate risk stratification in central conventional chondrosarcoma and may represent a valuable tool for improving its prognostication and clinical management.
Project description:Methylation Mediated Silencing of Protein Kinase C Zeta Induces Apoptosis Avoidance through ATM/Chk-2 Inactivation in Dedifferentiated Chondrosarcoma
Project description:Gene expression profiling of 17 fresh frozen chondrosarcoma biopsies using the Human-6 v2 Expression BeadChip (Illumina Inc., San Diego, CA, USA). DNA copy number analyses was also performed in these tumors. Keywords: chondrosarcoma, gene expression profiling, Illumina
Project description:DNA methylation and copy number variation (CNV) profiling has emerged as a promising tool for the classification of bone and soft tissue tumors. We evaluated its utility in cartilage tumors, where distinguishing low-grade from high-grade conventional central chondrosarcoma (CS) as well as atypical cartilaginous tumors (ACT) from enchondromas are frequent diagnostic challenges, particularly on biopsy material. We analyzed 214 chondrogenic tumors, including enchondromas, ACT, conventional central, dedifferentiated, and clear cell chondrosarcomas, and determined their IDH1/2 mutation status. Unsupervised dimensionality reduction of genome-wide DNA methylation patterns revealed four clusters among IDH-mutant tumors (IDH-MUT-1: mostly enchondromas and ACT and some high-grade CS; IDH-MUT-2: predominantly high-grade CS; IDH-MUT-3: largely dedifferentiated CS; IDH-MUT-HN: distinct head and neck group with markedly different methylation pattern) and two clusters among IDH-wildtype tumors (IDH-WT-1 and IDH-WT-2: both primarily high-grade CS, with IDH-WT-2 showing higher tumor grade and more extensive CNVs). Clear cell chondrosarcomas formed a separate cluster (CC). The amount of CNVs, including loss of CDKN2A, increased with tumor grade, reflecting increased genomic instability during chondrosarcoma progression. Supervised classifiers trained separately, both on methylation and CNV data, distinguished low- and high-grade cartilaginous tumors with AUC values of 0.87–0.97 and 85–90% accuracy. Furthermore, we tested whether dedifferentiated chondrosarcoma (DDCS) can be distinguished from metastatic carcinomas and other high-grade sarcomas of bone. Across 246 reference samples, a supervised classifier achieved 97.2% accuracy (AUC 99.8%) and correctly identified 30/32 (93.8%) DDCS. These results indicate that DNA methylation and CNV data analysis provide a valuable tool for distinguishing most low- and high-grade chondrosarcomas, with additional utility also in differentiating DDCS from morphologic mimics.
Project description:To investigate the gene expression profiling in bone diseases including osteoathritis (OA) and bone cancer (chondrosarcoma), different chondrocytes were isolated and assessed. For OA, the paired normal and OA chondrocytes were isolated from patient with total knee replacement surgery. Identification and delineation of dys-regulated genes between normal and OA chondrocytes and the regulatory mechanisms may provide the opportunity to treat OA. Also, the comparison with normal chondrocyte and chondrosarcoma cell lline (JJ012) gene expression profiling to identify the novel targets for chondrosarcoma therapies.