Project description:The majority of meningiomas are benign tumors associated with favorable outcomes; however, the less common aggressive variants with unfavorable outcomes often recur and may be due to sub-populations of less-differentiated cells residing within the tumor. These sub-populations of tumor cells, termed tumor-initiating cells, may be isolated from heterogeneous tumors when sorted or cultured in defined medium designed for enrichment of the tumor-initiating cells. We report the isolation and characterization of a population of tumor-initiating cells derived from an atypical meningioma. These meningioma-initiating cells (MICs) self-renew, differentiate, and can recapitulate the histological characteristics of the parental tumor when transplanted into athymic nude mice. Immunohistochemistry reveals protein expression patterns similar to neural stem and progenitor cells while genomic profiling verified the isolation of cancer cells (with defined meningioma chromosomal aberrations) from the bulk tumor. Furthermore, microarray analysis of gene expression reveals that many epithelial to mesenchymal transition genes are upregulated in the MICs, consistent with the presence of both neural stem cell and mature neural cell molecular markers seen in the derived cultures. Pathway analysis identifies biochemical processes and gene networks related to aberrant cell cycle progression, particularly the loss of heterozygosity of tumor suppressor genes CDKN2A (p16INK4A), p14ARF, and CDKN2B (p15INK4B). Flow cytometric analysis revealed the expression of CD44 and activated leukocyte adhesion molecule (ALCAM/CD166); these may prove to be markers able to identify this cell type. In conclusion, we identify a tumor-initiating population from an atypical meningioma that displays a unique phenotype and these results provide increased understanding of atypical meningioma progression. Part 1 of 2: Affymetrix SNP arrays were performed according to the manufacturer's directions on DNA extracted from primary tissue and their counterpart cell lines Part 2 of 2: Illumina gene expression array analysis was performed according to the manufacturer's directions on RNA extracted from cultured primary Meningioma and neural stem cell lines
Project description:The majority of meningiomas are benign tumors associated with favorable outcomes; however, the less common aggressive variants with unfavorable outcomes often recur and may be due to sub-populations of less-differentiated cells residing within the tumor. These sub-populations of tumor cells, termed tumor-initiating cells, may be isolated from heterogeneous tumors when sorted or cultured in defined medium designed for enrichment of the tumor-initiating cells. We report the isolation and characterization of a population of tumor-initiating cells derived from an atypical meningioma. These meningioma-initiating cells (MICs) self-renew, differentiate, and can recapitulate the histological characteristics of the parental tumor when transplanted into athymic nude mice. Immunohistochemistry reveals protein expression patterns similar to neural stem and progenitor cells while genomic profiling verified the isolation of cancer cells (with defined meningioma chromosomal aberrations) from the bulk tumor. Furthermore, microarray analysis of gene expression reveals that many epithelial to mesenchymal transition genes are upregulated in the MICs, consistent with the presence of both neural stem cell and mature neural cell molecular markers seen in the derived cultures. Pathway analysis identifies biochemical processes and gene networks related to aberrant cell cycle progression, particularly the loss of heterozygosity of tumor suppressor genes CDKN2A (p16INK4A), p14ARF, and CDKN2B (p15INK4B). Flow cytometric analysis revealed the expression of CD44 and activated leukocyte adhesion molecule (ALCAM/CD166); these may prove to be markers able to identify this cell type. In conclusion, we identify a tumor-initiating population from an atypical meningioma that displays a unique phenotype and these results provide increased understanding of atypical meningioma progression.
Project description:Current lack of insight into mechanisms governing breast cancer metastasis has precluded development of curative therapies. Metastasis-initiating cells (MICs) are cancer cells uniquely equipped to establish metastatic outgrowths and are thought to cause recurrence and therapeutic resistance. Using various models of early metastatic disease, we have uncovered mechanisms by which certain primary tumors can prevent MICs from generating secondary tumors. In such cases, the primary tumor elicits a systemic immune response involving IL-1β expressing innate inflammatory cells that infiltrate the distant MIC microenvironment. Elevated IL-1β levels at the metastatic site prevent MICs from generating their highly proliferative E-cadherin-positive epithelial progeny. Thus, when the inherent plasticity of MICs is impeded, robustly growing tumors cannot be established. Ablation of the pro-inflammatory response or IL-1R inhibition relieves the block in differentiation and results in MIC colonization. Our data reveal complex and potentially life-prolonging interactions that occur between primary tumors and disseminated MICs that could be exploited to improve survival of patients at risk for metastatic disease.
Project description:Transcription profiling by array of human primary astrocytes, cancer stem cells derived from astrocytes overexpressing various oncogenic and iPSC-inducing factors, glioma stem cells and gliblastomat cell line to compare their expression profiles and tumor-initiating capabilities
Project description:In this study, we characterize the fusion protein produced by the EPC1-PHF1 translocation in Low Grade Endometrial Stromal Sarcoma (LG-ESS) and Ossifying FibroMyxoid Tumors (OFMT). We express the fusion protein and necessary controls in K562 Cells. The fusion protein assembles a mega-complex harboring both NuA4/TIP60 and PRC2 subunits and enzymatic activities and leads to mislocalization of chromatin marks in the genome, linked to aberrant gene expression.
Project description:Kynureninase is a member of a large family of catalytically diverse but structurally homologous pyridoxal 5'-phosphate (PLP) dependent enzymes known as the aspartate aminotransferase superfamily or alpha-family. The Homo sapiens and other eukaryotic constitutive kynureninases preferentially catalyze the hydrolytic cleavage of 3-hydroxy-l-kynurenine to produce 3-hydroxyanthranilate and l-alanine, while l-kynurenine is the substrate of many prokaryotic inducible kynureninases. The human enzyme was cloned with an N-terminal hexahistidine tag, expressed, and purified from a bacterial expression system using Ni metal ion affinity chromatography. Kinetic characterization of the recombinant enzyme reveals classic Michaelis-Menten behavior, with a Km of 28.3 +/- 1.9 microM and a specific activity of 1.75 micromol min-1 mg-1 for 3-hydroxy-dl-kynurenine. Crystals of recombinant kynureninase that diffracted to 2.0 A were obtained, and the atomic structure of the PLP-bound holoenzyme was determined by molecular replacement using the Pseudomonas fluorescens kynureninase structure (PDB entry 1qz9) as the phasing model. A structural superposition with the P. fluorescens kynureninase revealed that these two structures resemble the "open" and "closed" conformations of aspartate aminotransferase. The comparison illustrates the dynamic nature of these proteins' small domains and reveals a role for Arg-434 similar to its role in other AAT alpha-family members. Docking of 3-hydroxy-l-kynurenine into the human kynureninase active site suggests that Asn-333 and His-102 are involved in substrate binding and molecular discrimination between inducible and constitutive kynureninase substrates.
Project description:Gene expression profiling of immortalized human mesenchymal stem cells with hTERT/E6/E7 transfected MSCs. hTERT may change gene expression in MSCs. Goal was to determine the gene expressions of immortalized MSCs.