Project description:In this study, pediatric ALL patient-derived xenografts (PDXs) inherently resistant to glucocorticoids were cultured in vitro. The study aims to determine discrepancy in gene expressions between different xeno strains.
Project description:In this study, pediatric ALL patient-derived xenografts (PDXs) inherently resistant to glucocorticoids were cultured in vitro. The study aims to determine discrepancy in gene expressions between different xeno strains. The same xenograft was innoculated into 3 mice. Spleen-harvest xenograft samples were analyzed using microarray.
Project description:Glioblastoma (GBM) patient-derived orthotopic xenografts (PDOXs) were derived from organotypic spheroids obtained from patient tumor samples. To detect whether gene expression profiles of GBM patient tumors are retained in PDOXs, we performed genome-wide transcript analysis by human-specific microarrays . In parallel, we analyzed GBM cell cultures and corresponding intracranial xenografts from stem-like (NCH421k, NCH644) and adherent GBM cell lines (U87, U251). PDOXs show a better transcriptomic resemblance with patient tumors than other preclinical models. The major difference is largely explained by the depletion of human-derived non-malignant cells.
Project description:Glioblastoma is the most common type of malignant brain tumor among adults. We used single-cell RNA sequencing (scRNA-seq) to analyze the diversity of glioblastoma cells.
Project description:Brain tumors are the leading cause of cancer-related death in children. Experimental in vitro models that faithfully capture the hallmarks and tumor heterogeneity of pediatric brain cancer are limited and hard to establish. We present a protocol that enables efficient generation, expansion and biobanking of pediatric brain cancer organoids. Utilizing our protocol, we have established patient-derived organoids (PDOs) from ependymomas, medulloblastomas, low-grade glial tumors and patient-derived xenograft organoids (PDXOs) from medulloblastoma xenografts. PDOs and PDXOs recapitulate histological features, DNA methylation profiles and intratumor heterogeneity of the tumors from which they were derived. We also showed that PDOs can be xenografted. Most interestingly, when subjected to the same routinely applied therapeutic regimens, PDOs respond similarly to the patients. Taken together, our study highlights the potential of PDOs and PDXOs for research and translational applications for personalized medicine.
Project description:Glucocorticoids are critical components of combination chemotherapy regimens in pediatric acute lymphoblastic leukemia (ALL). The pro-apoptotic BIM protein is an important mediator of glucocorticoid-induced apoptosis in normal and malignant lymphocytes, while the anti-apoptotic BCL2 confers resistance. The signaling pathways regulating BIM and BCL2 expression in glucocorticoid-treated lymphoid cells remain unclear. In this study, pediatric ALL patient-derived xenografts (PDXs) inherently sensitive or resistant to glucocorticoids were exposed to dexamethasone in vivo. In order to understand the basis for differential in vivo glucocorticoid sensitivity of PDXs, microarray analysis of gene expression was carried out on 5 each of dexamethasone-sensitive and resistant PDXs . This provided a global understanding of dexamethasone-induced signaling cascades in ALL cells in vivo, and especialy identified the genes that are involved in transducing the apoptotic signal, upstream of BIM/BCL2 dynamic interactions.