Project description:Gene expression profiling revealed over-representation of a distinct (proneural-like) expression signature in long-term survivors that was linked to IDH1/2 mutation. However, among the IDH1/2-wildtype patients, tumors from long-term survivors did not show distinct gene expression profiles and included proneural, classical and mesenchymal glioblastoma subtypes. We performed genome- and/or transcriptome-wide molecular profiling of primary tumor samples from 70 glioblastoma patients of the German Glioma Network, including 23 longterm survivors with >36 months overall survival (OS), 16 short-term survivors with <12 months OS, and 31 patients with intermediate OS For this study, we screened prospectively recruited patients with a histopathological reference diagnosis of glioblastoma, known KPS at diagnosis, information on extent of resection by early postoperative neuroimaging, available frozen tissue specimens from the initial operation, and documented clinical outcome.
Project description:Gene expression profiling revealed over-representation of a distinct (proneural-like) expression signature in long-term survivors that was linked to IDH1/2 mutation. However, among the IDH1/2-wildtype patients, tumors from long-term survivors did not show distinct gene expression profiles and included proneural, classical and mesenchymal glioblastoma subtypes. We performed genome- and/or transcriptome-wide molecular profiling of primary tumor samples from 70 glioblastoma patients of the German Glioma Network, including 23 longterm survivors with >36 months overall survival (OS), 16 short-term survivors with <12 months OS, and 31 patients with intermediate OS
Project description:In this study, we report a broad analysis of central tumor samples (C), from both Glioblastoma long term survivors (LT) and short term ones (ST), integrated by the same analysis performed on peritumoral areas (P) from the same patients. We provide data from SAGE analysis performed with deep sequencing.
Project description:Purpose: Autologous tumor lysate-pulsed dendritic cell (DC) vaccination has shown promising long-term survival in a cohort of patients with newly diagnosed glioblastoma. The purpose of this study was to better understand the mechanisms and modulation of the immune microenvironment underlying the clinical efficacy of DC-based vaccine therapy. Experimental Design: We performed bulk RNA sequencing on tumor samples from patients with newly diagnosed glioblastoma obtained prior to treatment with dendritic cell vaccination. We characterized the molecular mechanisms and immune microenvironments of long-term survivors (LTS, n= 8), medium-term survivors (MTS, n= 13), and short-term survivors (STS, n = 17). Results: There was an enrichment of the mesenchymal subtype of glioblastoma in the long-term survival group. Additionally, decreased tumor cell density, upregulation of cell surface markers, and increased neuronal activity were associated with the longer survival cohorts. Two microglia populations, one associated with increased survival and one associated with decreased survival in the DC-treated cohorts, but not standard of care (SOC) cohorts, are also potentially implicated in response to DC immunotherapy. There were increases in functional activity of the immune environment in longer survivor cohorts. Conclusions: These analyses suggest the potential to identify tumor-based predictive factors that may be associated with favorable responses to DC vaccination in glioblastoma patients; and if validated, these findings may enable better patient selection for future clinical trials.
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:Glioblastoma multiforme (GBM) is the most common and deadliest primary brain tumor. Its prognosis is inexorably unfavorable, as these tumors drive affected patients to death usually within 15 months after diagnosis (short term survivors, ST), with the only exception of a small fraction of patients (long term survivors, LT) surviving longer than 36 months. Even after the frontline therapeutic approach, including surgical resection followed by chemo- and radiotherapy, the cause of death in most cases is tumor recurrence, which occurs in peritumoral tissues in about 95% of patients. Here, we provide a comprehensive molecular analysis of a set of ST and LT samples derived from frankly tumoral areas (C) and from the peritumoral regions (P) of the same patients. By performing microRNA deep sequencing, we collected data showing that P areas differ from healthy white matter, but share with C samples, a number of microRNAs
Project description:As the evolution of miRNA genes has been found to be one of the important factors in formation of the modern type of man, we performed a comparative analysis of the evolution of miRNA genes in two archaic hominines, Homo sapiens neanderthalensis and Homo sapiens denisova, and elucidated the expression of their target mRNAs in bain.A comparative analysis of the genomes of primates, including species in the genus Homo, identified a group of miRNA genes having fixed substitutions with important implications for the evolution of Homo sapiens neanderthalensis and Homo sapiens denisova. The mRNAs targeted by miRNAs with mutations specific for Homo sapiens denisova exhibited enhanced expression during postnatal brain development in modern humans. By contrast, the expression of mRNAs targeted by miRNAs bearing variations specific for Homo sapiens neanderthalensis was shown to be enhanced in prenatal brain development.Our results highlight the importance of changes in miRNA gene sequences in the course of Homo sapiens denisova and Homo sapiens neanderthalensis evolution. The genetic alterations of miRNAs regulating the spatiotemporal expression of multiple genes in the prenatal and postnatal brain may contribute to the progressive evolution of brain function, which is consistent with the observations of fine technical and typological properties of tools and decorative items reported from archaeological Denisovan sites. The data also suggest that differential spatial-temporal regulation of gene products promoted by the subspecies-specific mutations in the miRNA genes might have occurred in the brains of Homo sapiens denisova and Homo sapiens neanderthalensis, potentially contributing to the cultural differences between these two archaic hominines.
Project description:PurposeWe investigated the evidence of recent positive selection in the human phototransduction system at single nucleotide polymorphism (SNP) and gene level.MethodsSNP genotyping data from the International HapMap Project for European, Eastern Asian, and African populations was used to discover differences in haplotype length and allele frequency between these populations. Numeric selection metrics were computed for each SNP and aggregated into gene-level metrics to measure evidence of recent positive selection. The level of recent positive selection in phototransduction genes was evaluated and compared to a set of genes shown previously to be under recent selection, and a set of highly conserved genes as positive and negative controls, respectively.ResultsSix of 20 phototransduction genes evaluated had gene-level selection metrics above the 90th percentile: RGS9, GNB1, RHO, PDE6G, GNAT1, and SLC24A1. The selection signal across these genes was found to be of similar magnitude to the positive control genes and much greater than the negative control genes.ConclusionsThere is evidence for selective pressure in the genes involved in retinal phototransduction, and traces of this selective pressure can be demonstrated using SNP-level and gene-level metrics of allelic variation. We hypothesize that the selective pressure on these genes was related to their role in low light vision and retinal adaptation to ambient light changes. Uncovering the underlying genetics of evolutionary adaptations in phototransduction not only allows greater understanding of vision and visual diseases, but also the development of patient-specific diagnostic and intervention strategies.
Project description:Cortical thickness has been investigated since the beginning of the 20th century, but we do not know how similar the cortical thickness profiles among humans are. In this study, the local similarity of cortical thickness profiles was investigated using sliding window methods. Here, we show that approximately 5% of the cortical thickness profiles are similarly expressed among humans while 45% of the cortical thickness profiles show a high level of heterogeneity. Therefore, heterogeneity is the rule, not the exception. Cortical thickness profiles of somatosensory homunculi and the anterior insula are consistent among humans, while the cortical thickness profiles of the motor homunculus are more variable. Cortical thickness profiles of homunculi that code for muscle position and skin stimulation are highly similar among humans despite large differences in sex, education, and age. This finding suggests that the structure of these cortices remains well preserved over a lifetime. Our observations possibly relativize opinions on cortical plasticity.