Project description:Prognosis of glioblastoma remains poor despite a great deal of research. In glioblastoma, the existence of glioblastoma stem cells (GSCs) has been shown, which are responsible for tumorigenesis, invasive capacity, and therapy resistance. One of cancer stem cell markers, Leucine-rich repeat-containing G-protein coupled receptor (Lgr5) plays a role in maintenance of GSCs, however, properties of the Lgr5 positive GSCs have not been fully understood. We applied the Sleeping-Beauty transposon-induced glioblastoma model to the Lgr5-GFP transgenic mice and sorted the GFP-positive cells from the neurosphere cultures derived from the mouse glioblastoma tissues. We found that the GFP-positive GSCs exhibited higher expression of Gli2 using a global gene expression analysis.
Project description:About 50% of colorectal cancer patients develop liver metastases. Patients with metastatic colorectal cancer have 5-year survival rates below 20% despite new therapeutic regimens. Tumor heterogeneity has been linked with poor clinical outcome, but was so far mainly studied via bulk genomic analyses. In this study we performed spatial proteomics via MALDI mass spectrometry imaging on six patient matched CRC primary tumor and liver metastases to characterize interpatient, intertumor and intratumor hetereogeneity. We found several peptide features that were enriched in vital tumor areas of primary tumors and liver metastasis and tentatively derived from tumor cell specific proteins such as annexin A4 and prelamin A/C. Liver metastases of colorectal cancer showed higher heterogeneity between patients than primary tumors while within patients both entities show similar intratumor heterogeneity sometimes organized in zonal pattern. Together our findings give new insights into the spatial proteomic heterogeneity of primary CRC and patient matched liver metastases.
Project description:To explore intratumor heterogeneity in gene expression profiles from patients with cervical cancer. Experimental Design: A total of 33 biopsies were obtained from 11 patients, sampling between two and five different areas for each tumor.The extracted RNA was hybridized onto the Affymetrix U133 Plus 2.0 oligonucleotide chip. The variance of expression within a patient (W), between patients (B) and the total variance (T =W + B) were calculated for each ProbeSet, and the ratio W/T was used as a measure of intratumor heterogeneity. Gene Ontology functional analysis was done to assess the function of genes that had high W/T (top 10%) and low W/T (bottom 10%) values.
Project description:Brain tumors are among the most malignant cancers and can arise from neural stem cells or oligodendrocyte progenitor cells (OPCs). Glioma-propagating cells (GPCs) that have stem-like properties have been derived from tumor variants such as glioblastoma multiforme (GBM) and oligodendroglial tumors, the latter being more chemosensitive with better prognosis. It has been suggested that such differences in chemosensitivity arise from the different profiles of OPCs versus neural stem cells. We thus explored if GPCs derived from these glioma variants can serve as reliable in vitro culture systems for studies. We utilized gene expression analyses, since GBM and oligodendrogliomas can be molecularly classified. Accordingly, we derived a gene signature distinguishing oligodendroglial GPCs from GBM GPCs collated from different studies, which was enriched for the Wnt, Notch and TGF-beta pathways. Using a novel method in glioma biology, the Connectivity Map, we mapped the strength of gene signature association with patient gene expression profiles in 2 independent glioma databases [GSE16011, http://caintegrator-info.nci.nih.gov/rembrandt]. Our gene signature consistently stratified survival in glioma patients. This data would suggest that in vitro low passage GPCs are similarly driven by transcriptomic changes that characterize the favorable outcome of oligodendrogliomas over GBM. Additionally, the gene signature was associated with the 1p/19q co-deletion status, the current clinical indicator of chemosensitivity. Our gene signature detects molecular heterogeneity in oligodendroglioma patients that cannot be accounted for by histology or the 1p/19q status alone, and highlights the limitation of morphology-based histological analyses in tumor classification, consequently impacting on treatment decisions. Total RNA obtained from primary neurosphere culture from brain tumor specimens of 6 patients were compared. Replicate arrays were performed for all 6 neurosphere cultures.
Project description:It is currently challenging to adequately model the growth and migration of glioblastoma using 2D in vitro culture systems as they quickly lose the original, patient-specific identity and heterogeneity. However, with the advent of 3D cell cultures and human induced pluripotent stem cells (iPSCs)-derived cerebral organoids (COs), studies demonstrate that the glioblastoma-cerebral organoid (GLICO) co-culture model helps to preserve the phenotype of the patient-specific tissue. Here we aimed to set up such a model using mature COs and develop a pipeline for subsequent analysis of co-cultured glioblastoma. Our data demonstrates that the growth and migration of the glioblastoma cell line within the mature COs are significantly increased in the presence of extracellular matrix proteins, shortening the time needed for glioblastoma to initiate migration. We also describe in detail the method for the visualization and quantification of these migrating cells within the GLICO model. Lastly, we show that this co-culture model (and the human brain-like microenvironment) can significantly transform the gene expression profile of the established U87 glioblastoma cell line into proneural and classical glioblastoma cell types.
Project description:To identify proneural, neural, classical and mesenchymal gene expression signature (Verhaak's classification) in human glioblastoma, a microarray analysis on 16 patient-derived glioblastoma stem cell cultures was performed.
Project description:Glioblastoma multiforme (GBM) is a lethal malignancy whose clinical intransigence has been linked to extensive intra-clonal genetic and phenotypic diversity and therapeutic resistance of cancer stem cells (CSCs). This interpretation embodies an implicit assumption that CSCs are themselves genetically diverse. To test this, we screened neurosphere cultures by SNP arrays to identify copy number alterations (CNA) (minimum of three) that could be visualised in single cells by multi-colour FISH. Interrogation of neurosphere-derived cells (from four patients) and cells derived from secondary transplants of these same cells in Nod/Scid mice allowed us to infer clonal phylogenic architecture and the likely derivation of functional CSCs. This proof-of-principle experiment revealed that more than one sub-clone (but not all) in each GBM had functionally defined, genetically distinct stem cells.
Project description:We classified samples and deciphered a key genes signature of intratumor heterogeneity by Principal Component Analysis and Weighted Gene Co-expression Network Analysis. We provide a signature of key cancer-heterogeneity genes highly associated with the intratumor spatial gradient and show that it is enriched in genes with correlation between methylation and expression levels.
Project description:TGF-beta has an oncogenic response in glioblastoma and it is considered to be a therapeutic target. We evaluated the effect of TGF-beta inhibition in glioblastoma. Differential gene expression analysis of patient-derived primary cultured glioblastoma cells treated with the TGF-beta receptor inhibitor, LY2109761 11 patient-derived cell cultures from 11 patients were treated with 2microM of the TGF-beta receptor inhibitor, LY2109761, for 3 hours or left untreated and RNA was isolated and microarray analysis was performed