Project description:MicroRNAs (miRNAs) are small (21-25 nucleotide in length) non-coding RNA molecules that negatively regulate protein expression. They are linked to cancer development and maintenance. In this work, studying gene expression profiles of 340 mammalian miRNAs with DNA microarrays, we selected 10 miRNAs gene features able to distinguish primary from secondary glioblastoma type; furthermore we verified that miR-21 and miR-155 up-regulatation seems to characterize the glioblastoma tumour state since it was found up-regulated in all samples analyzed compared to adult brain noneoplastic tissue. Since miR-21 function in glioblastoma cells was addressed previously we concentrated our efforts on miR-155 function. We found that miR-155 levels were markedly elevated both in primary and secondary glioblastomas tumours, in glioblastoma cell cultures and in 4 glioblastoma cell lines (U87, A172, LN229, and LN308) compared with adult brain tissue, CHP212-neuroblastoma cell lines and DAOY-1-medulloblastoma cell line. Since one of the miR-155 target was gamma-aminobutyric acid (GABA) A receptor (GABRA1) we verified if there was a relation between miR-155 up-regulation and GABRA1 expression. We demonstrated that, in cultured glioblastoma cells, knockdown of miR-155, which lower miR-155 expression to normal level, restore the normal expression of the gamma-aminobutyric acid (GABA) A receptor (GABRA1), making glioblastoma cells responsive to GABA cell cycle inhibiting signals. Our data suggest that aberrantly over-expressed miR-155 contribute to the malignant phenotype of the glioblastoma cells, promoting their unlimited growth. Keywords: miRNA expression profile We studied the expression profiles of 340 miRNAs in 97 glioblastoma tissues, of which 66 were primary glioblastomas and 27 were secondary glioblastomas. We have 66 replicates of primary glioblastoma and 27 replicates of secondary glioblastoma, each hybridized with the respective adult non-neoplastic brain tissue as a control.
Project description:We performed scATAC-seq on primary glioblastoma tissue samples taken at time of initial resection to map the global chromatin profiles of glioblastoma cells and associated non-neoplastic cells
Project description:MicroRNAs (miRNAs) are small (21-25 nucleotide in length) non-coding RNA molecules that negatively regulate protein expression. They are linked to cancer development and maintenance. In this work, studying gene expression profiles of 340 mammalian miRNAs with DNA microarrays, we selected 10 miRNAs gene features able to distinguish primary from secondary glioblastoma type; furthermore we verified that miR-21 and miR-155 up-regulatation seems to characterize the glioblastoma tumour state since it was found up-regulated in all samples analyzed compared to adult brain noneoplastic tissue. Since miR-21 function in glioblastoma cells was addressed previously we concentrated our efforts on miR-155 function. We found that miR-155 levels were markedly elevated both in primary and secondary glioblastomas tumours, in glioblastoma cell cultures and in 4 glioblastoma cell lines (U87, A172, LN229, and LN308) compared with adult brain tissue, CHP212-neuroblastoma cell lines and DAOY-1-medulloblastoma cell line. Since one of the miR-155 target was gamma-aminobutyric acid (GABA) A receptor (GABRA1) we verified if there was a relation between miR-155 up-regulation and GABRA1 expression. We demonstrated that, in cultured glioblastoma cells, knockdown of miR-155, which lower miR-155 expression to normal level, restore the normal expression of the gamma-aminobutyric acid (GABA) A receptor (GABRA1), making glioblastoma cells responsive to GABA cell cycle inhibiting signals. Our data suggest that aberrantly over-expressed miR-155 contribute to the malignant phenotype of the glioblastoma cells, promoting their unlimited growth. Keywords: miRNA expression profile
Project description:Expression data from five primary human glioblastomas (frozen surgical resection) and one non-neoplastic adult brain (frozen autopsy tissue)
Project description:Glioblastoma is an aggressive diffusely infiltrating neoplasm that spreads beyond surgical resection margins, where it intermingles with non-neoplastic brain cells. This complex microenvironment harbouring infiltrating glioma and non-neoplastic brain cells is the origin of tumor recurrence. Thus, understanding the cellular and molecular features of the glioma microenvironment is therapeutically and prognostically important. Here, we used single-nucleus RNA sequencing (snRNAseq) of primary and recurrent glioma to define three compositional ‘tissue-states’ rooted in cohabitation of cell-types and transcriptional states. These comprise a state featuring A) minimally infiltrated-brain, B) reactive inflamed infiltrated tissue, and C) cellular tumor. Spatial transcriptomics confirmed that the cell-types and transcriptomics states which compositionally cohabitate indeed do colocalize in space. Tissue states are clinically significant because they correlate with radiographic, histopathologic, and prognostic features. We found that in addition to enrichment of tissue state B signature, enrichment of both neoplastic and non-neoplastic cell-type gene signatures in tissue state B correlated with decreased survival. Importantly, we found that our compositionally defined tissue states are enriched in distinct metabolic pathways. One such pathway is fatty acid biosynthesis, which was enriched in tissue state B – a state enriched in recurrent glioblastoma and composed of astrocyte-like/mesenchymal glioma cells, reactive astrocytes resembling those seen in neurodegeneration, and monocyte-like myeloid cells. We discovered that targeting fatty acid synthesis was sufficient to deplete the transcriptional signature of tissue state B. Our findings define a novel compositional approach to the glioma infiltrated tissue which allows us to discover prognostic and targetable features, paving the way to new mechanistic and therapeutic discoveries.
Project description:Glioblastoma is an aggressive diffusely infiltrating neoplasm that spreads beyond surgical resection margins, where it intermingles with non-neoplastic brain cells. This complex microenvironment harbouring infiltrating glioma and non-neoplastic brain cells is the origin of tumor recurrence. Thus, understanding the cellular and molecular features of the glioma microenvironment is therapeutically and prognostically important. Here, we used single-nucleus RNA sequencing (snRNAseq) of primary and recurrent glioma to define three compositional ‘tissue-states’ rooted in cohabitation of cell-types and transcriptional states. These comprise a state featuring A) minimally infiltrated-brain, B) reactive inflamed infiltrated tissue, and C) cellular tumor. Spatial transcriptomics confirmed that the cell-types and transcriptomics states which compositionally cohabitate indeed do colocalize in space. Tissue states are clinically significant because they correlate with radiographic, histopathologic, and prognostic features. We found that in addition to enrichment of tissue state B signature, enrichment of both neoplastic and non-neoplastic cell-type gene signatures in tissue state B correlated with decreased survival. Importantly, we found that our compositionally defined tissue states are enriched in distinct metabolic pathways. One such pathway is fatty acid biosynthesis, which was enriched in tissue state B – a state enriched in recurrent glioblastoma and composed of astrocyte-like/mesenchymal glioma cells, reactive astrocytes resembling those seen in neurodegeneration, and monocyte-like myeloid cells. We discovered that targeting fatty acid synthesis was sufficient to deplete the transcriptional signature of tissue state B. Our findings define a novel compositional approach to the glioma infiltrated tissue which allows us to discover prognostic and targetable features, paving the way to new mechanistic and therapeutic discoveries.
Project description:Microarray-based gene expression analysis identified genes differentially expressed in 10 glioblastoma spheroid cultures compared to a non-neoplastic spheroid culture isolated from the bulbus olfactorius In this study, a set of 10 glioblastoma spheroid cultures was used to acquire expression profiles of a total of 17 093 transcripts, leading to the identification of differentially expressed genes compared to a non-neoplastic brain spheroid culture
Project description:We performed scATAC-seq on glioblastoma tissue samples taken at time of recurrence to map the global chromatin profiles of glioblastoma cells and associated non-neoplastic cells