Project description:Novel prognostic subclasses of high-grade astrocytoma are identified and discovered to resemble stages in neurogenesis. One tumor class displaying neuronal lineage markers shows longer survival, while two tumor classes enriched for neural stem cell markers display equally short survival. Poor prognosis subclasses exhibit either markers of proliferation or of angiogenesis and mesenchyme. Analysis of gene expression data is described in Phillips et al., Cancer Cell, 2006. Experiment Overall Design: 77 primary high-grade astrocytomas and 23 matched recurrences were profiled to identify changes in gene expression that relate to both survival and disease progression. Samples include WHO grade III and IV astrocytomas with a wide range of survival times.
Project description:Diffuse gliomas represent the most prevalent class of primary brain tumor. Despite significant recent advances in the understanding of glioblastoma (WHO IV), its most malignant subtype, lower-grade (WHO II and III) glioma variants remain comparatively understudied, especially in light of their notably variable clinical behavior. To examine the foundations of this heterogeneity, we performed multidimensional molecular profiling, including global transcriptional analysis, on 101 lower-grade diffuse astrocytic gliomas collected at our own institution, and validated our findings using publically available gene expression and copy number data from large independent patient cohorts. We found that IDH mutational status delineated molecularly and clinically distinct glioma subsets, with IDH mutant (IDH mt) tumors exhibiting TP53 mutations, PDGFRA overexpression, and prolonged survival, and IDH wild-type (IDH wt) tumors exhibiting EGFR amplification, PTEN loss, and unfavorable disease outcome. Furthermore, global expression profiling revealed three robust molecular subclasses within lower-grade diffuse astrocytic gliomas, two of which were predominantly IDH mt and one almost entirely IDH wt. IDH mt subclasses were distinguished from each other on the basis of TP53 mutations, DNA copy number abnormalities, and links to distinct stages of neurogenesis in the subventricular zone (SVZ). This latter finding implicates discrete pools of neuroglial progenitors as cells of origin for the different subclasses of IDH mt tumors. In summary, we have elucidated molecularly distinct subclasses of lower-grade diffuse astrocytic glioma that dictate clinical behavior and demonstrate fundamental associations with both IDH mutational status and neuroglial developmental stage. 80 tumor samples, one normal tissue sample (brain)
Project description:Novel prognostic subclasses of high-grade astrocytoma are identified and discovered to resemble stages in neurogenesis. One tumor class displaying neuronal lineage markers shows longer survival, while two tumor classes enriched for neural stem cell markers display equally short survival. Poor prognosis subclasses exhibit either markers of proliferation or of angiogenesis and mesenchyme. Analysis of gene expression data is described in Phillips et al., Cancer Cell, 2006. Keywords: Disease state comparison
Project description:Diffuse gliomas represent the most prevalent class of primary brain tumor. Despite significant recent advances in the understanding of glioblastoma (WHO IV), its most malignant subtype, lower-grade (WHO II and III) glioma variants remain comparatively understudied, especially in light of their notably variable clinical behavior. To examine the foundations of this heterogeneity, we performed multidimensional molecular profiling, including global transcriptional analysis, on 101 lower-grade diffuse astrocytic gliomas collected at our own institution, and validated our findings using publically available gene expression and copy number data from large independent patient cohorts. We found that IDH mutational status delineated molecularly and clinically distinct glioma subsets, with IDH mutant (IDH mt) tumors exhibiting TP53 mutations, PDGFRA overexpression, and prolonged survival, and IDH wild-type (IDH wt) tumors exhibiting EGFR amplification, PTEN loss, and unfavorable disease outcome. Furthermore, global expression profiling revealed three robust molecular subclasses within lower-grade diffuse astrocytic gliomas, two of which were predominantly IDH mt and one almost entirely IDH wt. IDH mt subclasses were distinguished from each other on the basis of TP53 mutations, DNA copy number abnormalities, and links to distinct stages of neurogenesis in the subventricular zone (SVZ). This latter finding implicates discrete pools of neuroglial progenitors as cells of origin for the different subclasses of IDH mt tumors. In summary, we have elucidated molecularly distinct subclasses of lower-grade diffuse astrocytic glioma that dictate clinical behavior and demonstrate fundamental associations with both IDH mutational status and neuroglial developmental stage.
Project description:Astrocytic tumors are known for their high progression capacity and for high mortality rates; in this regard, proteins correlated to prognosis can aid medical conduct. Although several genetic changes related to progression from low to high-grade astrocytoma are already known, mRNA copies do not necessarily correlate with protein abundance and, therefore could shadow further comprehension about this tumor’s biology. This motivates us to seek for complementary strategies to study tumor progression at the protein level. Here we compare the proteomic profile of biopsies from patients with low-grade (diffuse, n=6) versus high-grade astrocytoma (anaplastic and glioblastomas, n =10), using shotgun proteomics. Data analysis performed with PatternLab for proteomics identified 5,206 and 6,004 proteins in the low- and high-grade groups, respectively. Our results revealed seventy-four differentially abundant proteins (p < 0.01); we then shortlist those related to greater malignancy. We also describe molecular pathways distinctly activated in the two groups, such as differences in the organization of the extracellular matrix, decisive both in tumor invasiveness and in signaling for cell division, which, together with marked contrasts in energy metabolism, are determining factors in the speed of growth and dissemination of these neoplasms. The degradation pathways of GABA, enriched in the low-grade group, is consistent with a favorable prognosis. Other functions such as platelet degranulation, apoptosis, and activation of the MAPK pathway were correlated to high-grade tumors and, consequently, unfavorable prognoses. Our results provide an important survey of molecular pathways involved in glioma pathogenesis for these histopathological groups.
Project description:Combing WHO classification and molecular characteristics to analysis gliomas more and more important. But Grade III glioma samples have a big difference within the group had not been reported as far as we know. In this study, we proposed a model to evaluate diagnosis and prognosis of Grade III glioma patients, and two independent datasets indicated that the model has a good predictive ability. Therefore, this strategy provides a new method to assist diagnosis and treatment of Grade III glioma patients.
Project description:Gastric cancer, a leading cause of cancer related deaths, is a heterogeneous disease, with little consensus on molecular subclasses and their clinical relevance. We describe four molecular subtypes linked with distinct patterns of molecular alterations, disease progression and prognosis viz. a) Microsatellite Instable: hypermutated intestinal subtype tumors occurring in antrum, best overall prognosis, lower frequency of recurrence (22%), with liver metastasis in 23% of recurred cases b) Mesenchymal-like: diffuse tumors with worst prognosis, a tendency to occur at an earlier age and highest recurrence (63%) with peritoneal seeding in 64% of recurred cases, low frequency of molecular alterations c) TP53-inactive with TP53 loss, presence of focal amplifications and chromosomal instability d) TP53-active marked by EBV infection and PIK3CA mutations. The key molecular mechanisms and associated survival patterns are validated in multiple independent cohorts, to provide a consistent and unified framework for further preclinical and clinical research. ACRG Gastric cohort: microarray profiles from 300 gastric tumors from gastric cancer patients.
Project description:High-grade gliomas are aggressive primary brain cancers with poor response to standard regimens, driven by immense heterogeneity. In isocitrate dehydrogenase (IDH) wild-type high-grade glioma (glioblastoma, GBM), increased intra-tumoral heterogeneity is associated with more aggressive disease. Recently, spatial technologies have emerged to dissect this complex heterogeneity within the tumor ecosystem by preserving cellular organization in situ. Here, we construct a high- resolution molecular landscape of GBM and IDH-mutant high-grade glioma patient samples to investigate the cellular subtypes and spatial communities that compose high-grade glioma using digital spatial profiling and spatial molecular imaging. This uncovered striking diversity of the tumor and immune microenvironment, that is embodied by the heterogeneity of the inferred copy- number alterations in the tumor. Reconstructing the tumor architecture revealed brain-intrinsic niches, composed of tumor cells reflecting brain cell types and microglia; and brain-extrinsic niches, populated by mesenchymal tumor cells and monocytes. We further reveal that cellular communication in these niches is underpinned by specific ligand-receptor pairs. This primary study reveals high levels of intra-tumoral heterogeneity in high-grade gliomas, associated with a diverse immune landscape within spatially localized regions.
Project description:Purpose: The most clearly established genetic hallmark in oligodendroglial tumors (OTs) is the combined loss of 1p/19q, a molecular alteration characteristic of tumors responding to therapy. Markers of tumoral progression have not yet been studied. Experimental Design: Novel markers of tumoral progression in OTs were sought through gene expression profiling analysis. Results: Unsupervised hierarchical cluster analysis classified OTs into two main groups associated with tumoral grade, independent of histological subtype and 1p/19q status. Differential gene expression analysis between low- and high-grade OTs revealed that only cell cycle-related genes were significantly upregulated in high-grade OTs. Among the deregulated genes, NDRG2 downregulation was detected in high-grade OTs with combined loss of 1p/19q. Expression analysis revealed low transcript levels of NDRG2 relative to non-tumoral brain tissue in 45% (9/20) of high-grade OTs. Furthermore, the low transcript levels of NDRG2 were significantly associated with a worse clinical outcome in patients. Transcript levels of NDRG2 were associated with promoter hypermethylation, which was detected in 38.4% (10/26) of high-grade OTs. The treatment of glioma cell lines T98 and LN18 with demethylating agents increased the mRNA expression levels of NDRG2 relative to the control cell line. Additionally, cell proliferation was significantly reduced and cell cycle was arrested in G1 phase after treatment with demethylating agents. Conclusions: Taken together, our results suggest that NDRG2 is a candidate tumor suppressor gene in OTs whose inactivation could be involved in tumoral progression and worse patient survival. The microarray study involved 28 glioma samples including oligodendrogliomas and oligoastrocytomas WHO grade II and III. Six non-tumoral brain tissues were used as controls, two of which were purchased from Stratagene (La Jolla, CA) and Clontech (Mountain View, CA). RNAs from several cell lines (Universal Human RNA, Stratagene, La Jolla, CA) was used as a standard reference in all hybridizations