Your browser doesn't support javascript.
loading
: 20 | 50 | 100
1 - 20 de 357
1.
ESMO Open ; 7(6): 100637, 2022 12.
Article En | MEDLINE | ID: mdl-36423362

BACKGROUND: COGNITION (Comprehensive assessment of clinical features, genomics and further molecular markers to identify patients with early breast cancer for enrolment on marker driven trials) is a diagnostic registry trial that employs genomic and transcriptomic profiling to identify biomarkers in patients with early breast cancer with a high risk for relapse after standard neoadjuvant chemotherapy (NACT) to guide genomics-driven targeted post-neoadjuvant therapy. PATIENTS AND METHODS: At National Center for Tumor Diseases Heidelberg patients were biopsied before starting NACT, and for patients with residual tumors after NACT additional biopsy material was collected. Whole-genome/exome and transcriptome sequencing were applied on tumor and corresponding blood samples. RESULTS: In the pilot phase 255 patients were enrolled, among which 213 were assessable: thereof 48.8% were identified to be at a high risk for relapse following NACT; 86.4% of 81 patients discussed in the molecular tumor board were eligible for a targeted therapy within the interventional multiarm phase II trial COGNITION-GUIDE (Genomics-guided targeted post neoadjuvant therapy in patients with early breast cancer) starting enrolment in Q4/2022. An in-depth longitudinal analysis at baseline and in residual tumor tissue of 16 patients revealed some cases with clonal evolution but largely stable genetic alterations, suggesting restricted selective pressure of broad-acting cytotoxic neoadjuvant chemotherapies. CONCLUSIONS: While most precision oncology initiatives focus on metastatic disease, the presented concept offers the opportunity to empower novel therapy options for patients with high-risk early breast cancer in the post-neoadjuvant setting within a biomarker-driven trial and provides the basis to test the value of precision oncology in a curative setting with the overarching goal to increase cure rates.


Breast Neoplasms , Female , Humans , Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Breast Neoplasms/drug therapy , Breast Neoplasms/genetics , Breast Neoplasms/pathology , Neoadjuvant Therapy , Neoplasm Recurrence, Local/drug therapy , Precision Medicine , Prospective Studies
2.
Neuropathol Appl Neurobiol ; 45(2): 108-118, 2019 02.
Article En | MEDLINE | ID: mdl-30326163

AIMS: Mutations of isocitrate dehydrogenase (IDH)1/2 affect almost all astrocytomas of WHO grade II and III. A subset of IDH-mutant astrocytic tumours progresses to IDH-mutant glioblastoma or presents with the histology of a glioblastoma at first presentation. We set out here to assess the molecular spectrum of IDH-mutant glioblastomas. METHODS: We performed an integrated molecular analysis of a mono-centric cohort (n = 97); assessed through genome-wide DNA methylation analysis, copy-number profiling and targeted next generation sequencing using a neurooncology-tailored gene panel. RESULTS: Of these 97 IDH-mutant glioblastomas, 68 had a glioblastoma at first presentation ('de novo' IDH-mutant glioblastoma) and 29 emerged from a prior low-grade lesion ('evolved' IDH-mutant glioblastoma). Unsupervised hierarchical clustering of DNA methylation data disclosed that IDH-mutant glioblastoma ('de novo' and 'evolved') formed a distinct group separate from other diffuse glioma subtypes. Homozygous deletions of CDKN2A/B were found to be associated with shorter survival. CONCLUSIONS: This study demonstrates DNA methylation patterns in IDH-mutant glioblastoma to be distinct from lower-grade astrocytic counterparts but homogeneous within de novo and evolved IDH-mutant glioblastomas, and identifies CDKN2A as a marker for possible genetic sub-stratification.


Astrocytoma/pathology , Brain Neoplasms/pathology , Glioblastoma/genetics , Glioma/pathology , Isocitrate Dehydrogenase/genetics , Adolescent , Adult , Aged , Aged, 80 and over , Astrocytoma/genetics , Brain Neoplasms/genetics , Glioma/genetics , Humans , Middle Aged , Mutation/genetics , Neoplasm Grading/methods , Young Adult
3.
Oncogene ; 36(37): 5231-5242, 2017 09 14.
Article En | MEDLINE | ID: mdl-28504719

Group3 medulloblastoma (MBG3) that predominantly occur in young children are usually associated with MYC amplification and/or overexpression, frequent metastasis and a dismal prognosis. Physiologically relevant MBG3 models are currently lacking, making inferences related to their cellular origin thus far limited. Using in utero electroporation, we here report that MBG3 mouse models can be developed in situ from different multipotent embryonic cerebellar progenitor cells via conditional expression of Myc and loss of Trp53 function in several Cre driver mouse lines. The Blbp-Cre driver that targets embryonic neural progenitors induced tumors exhibiting a large-cell/anaplastic histopathology adjacent to the fourth ventricle, recapitulating human MBG3. Enforced co-expression of luciferase together with Myc and a dominant-negative form of Trp53 revealed that GABAergic neuronal progenitors as well as cerebellar granule cells give rise to MBG3 with their distinct growth kinetics. Cross-species gene expression analysis revealed that these novel MBG3 models shared molecular characteristics with human MBG3, irrespective of their cellular origin. We here developed MBG3 mouse models in their physiological environment and we show that oncogenic insults drive this MB subgroup in different cerebellar lineages rather than in a specific cell of origin.


Cerebellar Neoplasms/genetics , Cerebellum/embryology , Cerebellum/pathology , Medulloblastoma/genetics , Proto-Oncogene Proteins c-myc/genetics , Animals , Cerebellar Neoplasms/metabolism , Cerebellar Neoplasms/pathology , Cerebellum/cytology , Cerebellum/metabolism , Disease Models, Animal , Female , Humans , Male , Medulloblastoma/metabolism , Medulloblastoma/pathology , Mice , Mice, Transgenic , Proto-Oncogene Proteins c-myc/metabolism , Transfection
4.
Oncogene ; 36(29): 4124-4134, 2017 07 20.
Article En | MEDLINE | ID: mdl-28319069

Antiestrogen-resistant and triple-negative breast tumors pose a serious clinical challenge because of limited treatment options. We assessed global gene expression changes in antiestrogen-sensitive compared with antiestrogen-resistant (two tamoxifen resistant and two fulvestrant resistant) MCF-7 breast cancer cell lines. The branched-chain amino acid transaminase 1 (BCAT1), which catalyzes the first step in the breakdown of branched-chain amino acids, was among the most upregulated transcripts in antiestrogen-resistant cells. Elevated BCAT1 expression was confirmed in relapsed tamoxifen-resistant breast tumor specimens. High intratumoral BCAT1 levels were associated with a reduced relapse-free survival in adjuvant tamoxifen-treated patients and overall survival in unselected patients. On a tissue microarray (n=1421), BCAT1 expression was detectable in 58% of unselected primary breast carcinomas and linked to a higher Ki-67 proliferation index, as well as histological grade. Interestingly, BCAT1 was predominantly expressed in estrogen receptor-α-negative/human epidermal growth factor receptor-2-positive (ERα-negative/HER-2-positive) and triple-negative breast cancers in independent patient cohorts. The inverse relationship between BCAT1 and ERα was corroborated in various breast cancer cell lines and pharmacological long-term depletion of ERα induced BCAT1 expression in vitro. Mechanistically, BCAT1 indirectly controlled expression of the cell cycle inhibitor p27Kip1 thereby affecting pRB. Correspondingly, phenotypic analyses using a lentiviral-mediated BCAT1 short hairpin RNA knockdown revealed that BCAT1 sustains proliferation in addition to migration and invasion and that its overexpression enhanced the capacity of antiestrogen-sensitive cells to grow in the presence of antiestrogens. Importantly, silencing of BCAT1 in an orthotopic triple-negative xenograft model resulted in a massive reduction of tumor volume in vivo, supporting our findings that BCAT1 is necessary for the growth of hormone-independent breast tumors.


Breast Neoplasms/metabolism , Estrogen Antagonists/pharmacology , Estrogen Receptor alpha/metabolism , Transaminases/genetics , Animals , Breast Neoplasms/drug therapy , Breast Neoplasms/genetics , Breast Neoplasms/pathology , Cell Line, Tumor , Cell Movement/physiology , Cell Proliferation/physiology , Drug Resistance, Neoplasm , Female , Gene Expression Profiling , Heterografts , Humans , MCF-7 Cells , Mice , Mice, Inbred BALB C , Tamoxifen/pharmacology , Transaminases/antagonists & inhibitors , Transaminases/biosynthesis , Transaminases/metabolism , Up-Regulation
5.
Leukemia ; 31(10): 2048-2056, 2017 10.
Article En | MEDLINE | ID: mdl-28196983

Recent developments in sequencing technologies led to the discovery of a novel form of genomic instability, termed chromothripsis. This catastrophic genomic event, involved in tumorigenesis, is characterized by tens to hundreds of simultaneously acquired locally clustered rearrangements on one chromosome. We hypothesized that leukemias developing in individuals with Ataxia Telangiectasia, who are born with two mutated copies of the ATM gene, an essential guardian of genome stability, would show a higher prevalence of chromothripsis due to the associated defect in DNA double-strand break repair. Using whole-genome sequencing, fluorescence in situ hybridization and RNA sequencing, we characterized the genomic landscape of Acute Lymphoblastic Leukemia (ALL) arising in patients with Ataxia Telangiectasia. We detected a high frequency of chromothriptic events in these tumors, specifically on acrocentric chromosomes, as compared with tumors from individuals with other types of DNA repair syndromes (27 cases total, 10 with Ataxia Telangiectasia). Our data suggest that the genomic landscape of Ataxia Telangiectasia ALL is clearly distinct from that of sporadic ALL. Mechanistically, short telomeres and compromised DNA damage response in cells of Ataxia Telangiectasia patients may be linked with frequent chromothripsis. Furthermore, we show that ATM loss is associated with increased chromothripsis prevalence in additional tumor entities.


Ataxia Telangiectasia Mutated Proteins/physiology , Ataxia Telangiectasia/genetics , Neoplasm Proteins/physiology , Precursor Cell Lymphoblastic Leukemia-Lymphoma/genetics , Adolescent , Ataxia Telangiectasia/complications , Ataxia Telangiectasia Mutated Proteins/deficiency , Ataxia Telangiectasia Mutated Proteins/genetics , Child , Child, Preschool , Chromosomes, Human/ultrastructure , Chromothripsis , DNA Repair/genetics , DNA, Neoplasm/genetics , Female , Genome, Human , Genomic Instability , Humans , In Situ Hybridization, Fluorescence , Male , Mutation , Neoplasm Proteins/deficiency , Neoplasm Proteins/genetics , Neoplasms/genetics , Precursor Cell Lymphoblastic Leukemia-Lymphoma/etiology , Precursor T-Cell Lymphoblastic Leukemia-Lymphoma/genetics , RNA, Neoplasm/genetics , Sequence Analysis, DNA , Sequence Analysis, RNA , Telomere Shortening/genetics , Transcriptome
6.
Leukemia ; 30(3): 570-9, 2016 Mar.
Article En | MEDLINE | ID: mdl-26522085

Chronic lymphocytic leukemia (CLL) is characterized by apoptosis resistance and a dysfunctional immune system. Previous reports suggested a potential role of myeloid cells in mediating these defects. However, the composition and function of CLL-associated myeloid cells have not been thoroughly investigated in vivo. Using the Eµ-TCL1 mouse model, we observed severe skewing of myeloid cell populations with CLL development. Monocytes and M2-like macrophages infiltrated the peritoneal cavity of leukemic mice. Monocytes also accumulated in the spleen in a CCR2-dependent manner, and were severely skewed toward Ly6C(low) patrolling or nonclassical phenotype. In addition, the percentage of MHC-II(hi) dendritic cells and macrophages significantly dropped in the spleen. Gene expression profiling of CLL-associated monocytes revealed aberrantly high PD-L1 expression and secretion of multiple inflammatory and immunosuppressive cytokines like interleukin-10, tumor necrosis factor-α and CXCL9. In vivo myeloid cell depletion using liposomal Clodronate resulted in a significant control of CLL development accompanied by a pronounced repair of innate immune cell phenotypes and a partial resolution of systemic inflammation. In addition, CLL-associated skewing of T cells toward antigen-experienced phenotypes was repaired. The presented data suggest that targeting nonmalignant myeloid cells might serve as a novel immunotherapeutical strategy for CLL.


Clodronic Acid/pharmacology , Gene Expression Regulation, Leukemic , Leukemia, Lymphocytic, Chronic, B-Cell/drug therapy , Macrophages/drug effects , Monocytes/drug effects , Animals , Antigens, Ly/genetics , Antigens, Ly/immunology , B7-H1 Antigen/genetics , B7-H1 Antigen/immunology , Chemokine CXCL9/genetics , Chemokine CXCL9/immunology , Dendritic Cells/drug effects , Dendritic Cells/immunology , Dendritic Cells/pathology , Disease Models, Animal , Humans , Immunophenotyping , Interleukin-10/genetics , Interleukin-10/immunology , Leukemia, Lymphocytic, Chronic, B-Cell/genetics , Leukemia, Lymphocytic, Chronic, B-Cell/immunology , Leukemia, Lymphocytic, Chronic, B-Cell/pathology , Macrophages/immunology , Macrophages/pathology , Mice , Mice, Transgenic , Monocytes/immunology , Monocytes/pathology , Peritoneal Cavity/pathology , Phenotype , Receptors, CCR2/genetics , Receptors, CCR2/immunology , Signal Transduction , Spleen/drug effects , Spleen/immunology , Spleen/pathology , T-Lymphocytes/drug effects , T-Lymphocytes/immunology , T-Lymphocytes/pathology , Tumor Necrosis Factor-alpha/genetics , Tumor Necrosis Factor-alpha/immunology
7.
Cell Death Differ ; 21(9): 1419-31, 2014 Sep.
Article En | MEDLINE | ID: mdl-24832469

p53 loss of heterozygosity (p53LOH) is frequently observed in Li-Fraumeni syndrome (LFS) patients who carry a mutant (Mut) p53 germ-line mutation. Here, we focused on elucidating the link between p53LOH and tumor development in stem cells (SCs). Although adult mesenchymal stem cells (MSCs) robustly underwent p53LOH, p53LOH in induced embryonic pluripotent stem cells (iPSCs) was significantly attenuated. Only SCs that underwent p53LOH induced malignant tumors in mice. These results may explain why LFS patients develop normally, yet acquire tumors in adulthood. Surprisingly, an analysis of single-cell sub-clones of iPSCs, MSCs and ex vivo bone marrow (BM) progenitors revealed that p53LOH is a bi-directional process, which may result in either the loss of wild-type (WT) or Mut p53 allele. Interestingly, most BM progenitors underwent Mutp53LOH. Our results suggest that the bi-directional p53LOH process may function as a cell-fate checkpoint. The loss of Mutp53 may be regarded as a DNA repair event leading to genome stability. Indeed, gene expression analysis of the p53LOH process revealed upregulation of a specific chromatin remodeler and a burst of DNA repair genes. However, in the case of loss of WTp53, cells are endowed with uncontrolled growth that promotes cancer.


Alleles , Loss of Heterozygosity , Stem Cells/metabolism , Tumor Suppressor Protein p53/genetics , Animals , Mice , Mice, Inbred C57BL , Mice, Inbred NOD , Mice, Nude , Mice, SCID , Tumor Suppressor Protein p53/metabolism
8.
Eye (Lond) ; 28(6): 662-71, 2014 Jun.
Article En | MEDLINE | ID: mdl-24603425

AIMS: Vascular perfusion may be impaired in primary open-angle glaucoma (POAG); thus, we evaluated a panel of markers in vascular tone-regulating genes in relation to POAG. METHODS: We used Illumina 660W-Quad array genotype data and pooled P-values from 3108 POAG cases and 3430 controls from the combined National Eye Institute Glaucoma Human Genetics Collaboration consortium and Glaucoma Genes and Environment studies. Using information from previous literature and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways, we compiled single-nucleotide polymorphisms (SNPs) in 186 vascular tone-regulating genes. We used the 'Pathway Analysis by Randomization Incorporating Structure' analysis software, which performed 1000 permutations to compare the overall pathway and selected genes with comparable randomly generated pathways and genes in their association with POAG. RESULTS: The vascular tone pathway was not associated with POAG overall or POAG subtypes, defined by the type of visual field loss (early paracentral loss (n=224 cases) or only peripheral loss (n=993 cases)) (permuted P≥0.20). In gene-based analyses, eight were associated with POAG overall at permuted P<0.001: PRKAA1, CAV1, ITPR3, EDNRB, GNB2, DNM2, HFE, and MYL9. Notably, six of these eight (the first six listed) code for factors involved in the endothelial nitric oxide synthase activity, and three of these six (CAV1, ITPR3, and EDNRB) were also associated with early paracentral loss at P<0.001, whereas none of the six genes reached P<0.001 for peripheral loss only. DISCUSSION: Although the assembled vascular tone SNP set was not associated with POAG, genes that code for local factors involved in setting vascular tone were associated with POAG.


Endothelium, Vascular/metabolism , Genetic Predisposition to Disease , Glaucoma, Open-Angle/genetics , Muscle, Smooth, Vascular/physiology , Polymorphism, Single Nucleotide , Signal Transduction/genetics , AMP-Activated Protein Kinases/genetics , Aged , Case-Control Studies , Caveolin 1/genetics , Dynamin II , Dynamins/genetics , Female , GTP-Binding Proteins/genetics , Genotype , Glaucoma, Open-Angle/physiopathology , Humans , Inositol 1,4,5-Trisphosphate Receptors/genetics , Intraocular Pressure , Male , Middle Aged , Nitric Oxide Synthase Type III/genetics , Receptor, Endothelin B , Receptors, Endothelin/genetics
9.
Cell Death Differ ; 21(6): 929-40, 2014 Jun.
Article En | MEDLINE | ID: mdl-24531536

Glioblastomas are highly aggressive brain tumours and are characterised by substantial cellular heterogeneity within a single tumour. A sub-population of glioblastoma stem-like cells (GSCs) that shares properties with neural precursor cells has been described, exhibiting resistance to therapy and therefore being considered responsible for the high recurrence rate in glioblastoma. To elucidate the underlying cellular processes we investigated the role of phosphatases in the GSC phenotype, using an in vitro phosphatome-wide RNA interference screen. We identified a set of genes, the knockdown of which induces a significant decrease in the glioma stem cell marker CD133, indicating a role in the glioblastoma stem-like phenotype. Among these genes, the ecto-nucleotidase ENPP1 (ectonucleotide pyrophosphatase/phosphodiesterase 1) was found to be highly expressed in GSCs compared with normal brain and neural stem cells. Knockdown of ENPP1 in cultured GSCs resulted in an overall downregulation of stem cell-associated genes, induction of differentiation into astrocytic cell lineage, impairment of sphere formation, in addition to increased cell death, accumulation of cells in G1/G0 cell cycle phase and sensitisation to chemotherapeutic treatment. Genome-wide gene expression analysis and nucleoside and nucleotide profiling revealed that knockdown of ENPP1 affects purine and pyrimidine metabolism, suggesting a link between ENPP1 expression and a balanced nucleoside-nucleotide pool in GSCs. The phenotypic changes in E-NPP1-deficient GSCs are assumed to be a consequence of decreased transcriptional function of E2F1. Together, these results reveal that E-NPP1, by acting upstream of E2F1, is indispensable for the maintenance of GSCs in vitro and hence required to keep GSCs in an undifferentiated, proliferative state.


Brain Neoplasms/genetics , Glioblastoma/genetics , Neural Stem Cells/metabolism , Phosphoric Diester Hydrolases/metabolism , Pyrophosphatases/metabolism , AC133 Antigen , Antigens, CD/biosynthesis , Brain Neoplasms/metabolism , Brain Neoplasms/pathology , Cell Cycle Checkpoints/genetics , Cell Differentiation/genetics , Cell Line, Tumor , Cell Lineage , E2F1 Transcription Factor/metabolism , Gene Expression Regulation, Neoplastic , Glioblastoma/metabolism , Glioblastoma/pathology , Glycoproteins/biosynthesis , Humans , Peptides , Phosphoric Diester Hydrolases/genetics , Pyrophosphatases/genetics
10.
Leukemia ; 28(6): 1289-98, 2014 Jun.
Article En | MEDLINE | ID: mdl-24280868

Chronic lymphocytic leukemia (CLL) is an incurable malignancy of mature B cells. One of the major challenges in treatment of CLL is the achievement of a complete remission to prevent relapse of disease originating from cells within lymphoid tissues and subsequent chemoresistance. In search for novel drugs that target CLL cells in protective microenvironments, we performed a fungal extract screen using cocultures of primary CLL cells with bone marrow-derived stromal cells. A secondary metabolite produced by Penicillium aquamarinium was identified as Chaetoglobosin A (ChA), a member of the cytochalasan family that showed preferential induction of apoptosis in CLL cells, even under culture conditions that mimic lymphoid tissues. In vitro testing of 89 CLL cases revealed effective targeting of CLL cells by ChA, independent of bad prognosis characteristics, like 17p deletion or TP53 mutation. To provide insight into its mechanism of action, we showed that ChA targets filamentous actin in CLL cells and thereby induces cell-cycle arrest and inhibits membrane ruffling and cell migration. Our data further revealed that ChA prevents CLL cell activation and sensitizes them for treatment with PI3K and BTK inhibitors, suggesting this compound as a novel potential drug for CLL.


Apoptosis/drug effects , Cytokinesis/drug effects , Cytoskeleton/drug effects , Indole Alkaloids/pharmacology , Leukemia, Lymphocytic, Chronic, B-Cell/pathology , Mycotoxins/pharmacology , Stromal Cells/drug effects , Actins/metabolism , Blotting, Western , Case-Control Studies , Cell Adhesion/drug effects , Cell Cycle/drug effects , Cell Movement/drug effects , Cell Proliferation/drug effects , Chromatography, High Pressure Liquid , Coculture Techniques , Cytoskeleton/metabolism , Flow Cytometry , Fungi/chemistry , Healthy Volunteers , Humans , Leukemia, Lymphocytic, Chronic, B-Cell/drug therapy , Leukemia, Lymphocytic, Chronic, B-Cell/metabolism , Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization , Stromal Cells/metabolism , Stromal Cells/pathology , Tumor Cells, Cultured
11.
Leukemia ; 27(2): 353-61, 2013 Feb.
Article En | MEDLINE | ID: mdl-22810507

Recently, the p53-miR-34a network has been identified to have an important role in tumorigenesis. As in acute myeloid leukemia with complex karyotype (CK-AML) TP53 alterations are the most common known molecular lesion, we further analyzed the p53-miR-34a axis in a large cohort of CK-AML with known TP53 status (TP53(altered), n=57; TP53(unaltered), n=31; altered indicates loss and/or mutation of TP53). Profiling microRNA (miRNA) expression delineated TP53 alteration-associated miRNA profiles, and identified miR-34a and miR-100 as the most significantly down- and upregulated miRNA, respectively. Moreover, we found a distinct miR-34a expression-linked gene expression profile enriched for genes belonging to p53-associated pathways, and implicated in cell cycle progression or apoptosis. Clinically, low miR-34a expression and TP53 alterations predicted for chemotherapy resistance and inferior outcome. Notably, in TP53(unaltered) CK-AML, high miR-34a expression predicted for inferior overall survival (OS), whereas in TP53(biallelic altered) CK-AML, high miR-34a expression pointed to better OS. Thus, detailed molecular profiling links impaired p53 to decreased miR-34a expression, but also identifies p53-independent miR-34a induction mechanisms as shown in TP53(biallelic altered) cell lines treated with 15-deoxy-Δ(12,14)-prostaglandin. An improved understanding of this mechanism might provide novel therapeutic options to restore miR-34a function and thereby induce cell cycle arrest and apoptosis in TP53(altered) CK-AML.


Biomarkers, Tumor/genetics , Chromosome Aberrations , Leukemia, Myeloid, Acute/genetics , MicroRNAs/genetics , Tumor Suppressor Protein p53/genetics , Adolescent , Adult , Aged , Cells, Cultured , Female , Gene Expression Profiling , Humans , Karyotyping , Leukemia, Myeloid, Acute/mortality , Male , Middle Aged , Oligonucleotide Array Sequence Analysis , Prognosis , RNA, Messenger/genetics , Real-Time Polymerase Chain Reaction , Reverse Transcriptase Polymerase Chain Reaction , Survival Rate , Young Adult
12.
Oncogene ; 31(27): 3235-43, 2012 Jul 05.
Article En | MEDLINE | ID: mdl-22056879

The concept of cancer stem-like cells (CSCs) has gained considerable attention in various solid tumors including glioblastoma, the most common primary brain tumor. This sub-population of tumor cells has been intensively investigated and their role in therapy resistance as well as tumor recurrence has been demonstrated. In that respect, development of therapeutic strategies that target CSCs (and possibly also the tumor bulk) appears a promising approach in patients suffering from primary brain tumors. In the present study, we utilized RNA interference (RNAi) to screen the complete human kinome and phosphatome (682 and 180 targets, respectively) in order to identify genes and pathways relevant for the survival of brain CSCs and thereby potential therapeutical targets for glioblastoma. We report of 46 putative candidates including known survival-related kinases and phosphatases. Interestingly, a number of genes identified are involved in metabolism, especially glycolysis, such as PDK1 and PKM2 and, most prominently PFKFB4. In vitro studies confirmed an essential role of PFKFB4 in the maintenance of brain CSCs. Furthermore, high PFKFB4 expression was associated with shorter survival of primary glioblastoma patients. Our findings support the importance of the glycolytic pathway in the maintenance of malignant glioma cells and brain CSCs and imply tumor metabolism as a promising therapeutic target in glioblastoma.


Glioma/genetics , Glioma/pathology , Neoplastic Stem Cells/metabolism , Neoplastic Stem Cells/pathology , Phosphofructokinase-2/deficiency , Phosphofructokinase-2/genetics , RNA Interference , Adenosine Triphosphate/biosynthesis , Brain Neoplasms/diagnosis , Brain Neoplasms/genetics , Brain Neoplasms/metabolism , Brain Neoplasms/pathology , Cell Death/genetics , Cell Survival/genetics , Gene Expression Regulation, Neoplastic/genetics , Glioma/diagnosis , Glioma/metabolism , Glycolysis/genetics , Humans , Isoenzymes/deficiency , Isoenzymes/genetics , Lactic Acid/biosynthesis , Lentivirus/genetics , Prognosis , RNA, Small Interfering/genetics
13.
Oncogene ; 31(29): 3409-18, 2012 Jul 19.
Article En | MEDLINE | ID: mdl-22158042

Deletions of chromosomal arms 1p and 19q are frequent in oligodendroglial tumours and linked to radio- and chemotherapy response as well as longer survival. The molecular mechanisms underlying this clinically important association are as yet unknown. Here, we studied the peroxiredoxin 1 (PRDX1) gene at 1p34.1 for promoter methylation and expression in primary gliomas and investigated its role in radio- and chemosensitivity of glioma cells in vitro. In total, we screened primary glioma tissues from 93 patients for methylation of the 5'-CpG island of PRDX1 by sodium bisulfite sequencing. PRDX1 mRNA and protein expression levels were determined in subsets of the tumours by quantitative PCR and western blot analysis, respectively. PRDX1 hypermethylation and reduced expression were frequently detected in oligodendroglial tumours and secondary glioblastomas, but not in primary glioblastomas. In oligodendroglial tumours, both PRDX1 hypermethylation and reduced mRNA expression were significantly associated with 1p/19q-deletion. Stable knockdown of PRDX1 by lentiviral transduction of short-hairpin (sh)RNA constructs significantly increased apoptosis and reduced cell viability of Hs683 glioma cells exposed to ionizing irradiation or temozolomide in vitro. Taken together, our findings indicate that epigenetic silencing of PRDX1 is frequent in 1p/19q-deleted oligodendroglial tumours and likely contributes to radio- and chemosensitivity of these tumours.


Chromosome Deletion , Chromosomes, Human, Pair 1/genetics , Glioma/pathology , Oligodendroglia/metabolism , Peroxiredoxins/genetics , Promoter Regions, Genetic/genetics , Radiation Tolerance/genetics , Adult , Aged , Apoptosis/drug effects , Apoptosis/genetics , Apoptosis/radiation effects , Cell Line, Tumor , CpG Islands/genetics , DNA Methylation/drug effects , DNA Methylation/radiation effects , Dacarbazine/analogs & derivatives , Dacarbazine/pharmacology , Down-Regulation/genetics , Female , Gene Knockdown Techniques , Gene Silencing , Glioma/drug therapy , Glioma/genetics , Glioma/radiotherapy , Humans , Isocitrate Dehydrogenase/genetics , Male , Middle Aged , Mutation , Oligodendroglia/drug effects , Oligodendroglia/pathology , Oligodendroglia/radiation effects , Peroxiredoxins/deficiency , Promoter Regions, Genetic/drug effects , Promoter Regions, Genetic/radiation effects , Temozolomide , Young Adult
14.
Article En | MEDLINE | ID: mdl-21095801

Surface electrodes in modern myoelectric prosthetics are often embedded in the prosthesis socket and make contact with the skin. These electrodes detect and amplify muscle action potentials from voluntary contractions of the muscle in the residual limb and are used to control the prosthetic's movement and function. There are a number of performance-related deficiencies associated with external electrodes including the maintenance of sufficient electromyogram (EMG) signal amplitude, extraneous noise acquisition, and proper electrode interface maintenance that are expected to be improved or eliminated using the proposed implanted sensors. This research seeks to investigate the design components for replacing external electrodes with fully-implantable myoelectric sensors that include a wireless interface to the prosthetic limbs. This implanted technology will allow prosthetic limb manufacturers to provide products with increased performance, capability, and patient-comfort. The EMG signals from the intramuscular recording electrode are amplified and wirelessly transmitted to a receiver in the prosthetic limb. Power to the implant is maintained using a rechargeable battery and an inductive energy transfer link from the prosthetic. A full experimental system was developed to demonstrate that a wireless biopotential sensor can be designed that meets the requirements of size, power, and performance for implantation.


Artificial Limbs , Electric Power Supplies , Electrodes, Implanted , Electromyography/instrumentation , Prosthesis Design/instrumentation , Wireless Technology/instrumentation
15.
Pathologe ; 31 Suppl 2: 211-4, 2010 Oct.
Article De | MEDLINE | ID: mdl-20711583

To establish precise diagnostic algorithms and standardised treatment of sarcomas in specialized centers, the interdisciplinary research group KoSar (sarcoma competence network) has been funded by German Cancer Aid. A sarcoma tissue repository and a diagnostic reference center have been set up, presently containing about 1000 accurately diagnosed sarcomas of different entities. Significant gene expression profiles for synovial sarcomas, leiomyosarcomas, myxoid liposarcomas and a small profile for myxofibrosarcomas as well as a new classification of angiosarcomas were defined. We systematically searched for activated signal transduction pathways in sarcoma cell lines and xenograft transplant models and candidate targets for molecular therapies were identified. Based on these results first clinical studies have been initiated by the German Interdisciplinary Sarcoma Study Group (GISG).


Sarcoma/genetics , Sarcoma/pathology , Animals , Biomedical Research , Cell Line, Tumor , Cooperative Behavior , Drug Evaluation, Preclinical , Fibrosarcoma/diagnosis , Fibrosarcoma/drug therapy , Fibrosarcoma/genetics , Fibrosarcoma/pathology , Gene Expression Profiling , Gene Expression Regulation, Neoplastic/genetics , Humans , Interdisciplinary Communication , Leiomyosarcoma/diagnosis , Leiomyosarcoma/drug therapy , Leiomyosarcoma/genetics , Leiomyosarcoma/pathology , Liposarcoma, Myxoid/diagnosis , Liposarcoma, Myxoid/drug therapy , Liposarcoma, Myxoid/genetics , Liposarcoma, Myxoid/pathology , Molecular Diagnostic Techniques , Molecular Targeted Therapy , Neoplasm Transplantation , Sarcoma/diagnosis , Sarcoma/drug therapy , Sarcoma, Synovial/diagnosis , Sarcoma, Synovial/drug therapy , Sarcoma, Synovial/genetics , Sarcoma, Synovial/pathology , Signal Transduction/genetics
16.
Gut ; 59(9): 1236-44, 2010 Sep.
Article En | MEDLINE | ID: mdl-20479215

BACKGROUND AND AIMS: Liver metastases are the leading cause of death in colorectal cancer. To gain better insight into the biology of metastasis and possibly identify new therapeutic targets we systematically investigated liver-metastasis-specific molecular aberrations. METHODS: Primary colorectal cancer (pCRC) and matched liver metastases (LMs) from the same patients were analysed by microarray-based comparative genomic hybridisation in 21 pairs and gene expression profiling in 18 pairs. Publicly available databases were used to confirm findings in independent datasets. RESULTS: Chromosome aberration patterns and expression profiles of pCRC and matched LMs were strikingly similar. Unsupervised cluster analysis of genomic data showed that 20/21 pairs were more similar to each other than to any other analysed tumour. A median of only 11 aberrations per patient was found to be different between pCRC and LM, and expression of only 16 genes was overall changed upon metastasis. One region on chromosome band 11p15.5 showed a characteristic gain in LMs in 6/21 patients. This gain could be confirmed in an independent dataset of LMs (n=50). Localised within this region, the growth factor IGF2 (p=0.003) and the intestinal stem cell specific transcription factor ASCL2 (p=0.029) were found to be over-expressed in affected LM. Several ASCL2 target genes were upregulated in this subgroup of LM, including the intestinal stem cell marker OLFM4 (p=0.013). The correlation between ASCL2 expression and four known direct transcriptional targets (LGR5, EPHB3, ETS2 and SOX9) could be confirmed in an independent expression dataset (n=50). CONCLUSIONS: With unprecedented resolution a striking conservation of genomic alterations was demonstrated in liver metastases, suggesting that metastasis typically occurs after the pCRC has fully matured. In addition, we characterised a subset of liver metastases with an ASCL2-related stem-cell signature likely to affect metastatic behaviour of tumour cells.


Basic Helix-Loop-Helix Transcription Factors/biosynthesis , Chromosomes, Human, Pair 11/genetics , Colorectal Neoplasms/metabolism , Insulin-Like Growth Factor II/biosynthesis , Liver Neoplasms/secondary , Basic Helix-Loop-Helix Transcription Factors/genetics , Chromosome Aberrations , Cluster Analysis , Colorectal Neoplasms/genetics , Gene Expression Profiling/methods , Genome/genetics , Humans , Insulin-Like Growth Factor II/genetics , Liver Neoplasms/genetics , Liver Neoplasms/metabolism , Neoplastic Stem Cells/metabolism , Oligonucleotide Array Sequence Analysis , Phenotype , Reverse Transcriptase Polymerase Chain Reaction/methods
17.
Oncogene ; 29(23): 3411-22, 2010 Jun 10.
Article En | MEDLINE | ID: mdl-20305691

All-trans retinoic acid is a potent promoter of cellular differentiation processes, which is used in cancer therapy. Glioblastoma spheroid cultures are enriched in tumor-initiating cells, and provide a model to test new treatment options in vitro. We investigated the molecular mechanisms of response to exposure to differentiation-promoting conditions in such cultures. Microarray analyses of five independent cultures showed that after induction of differentiation, inhibitors of transforming growth factor-beta/bone morphogenetic protein, Wnt/beta-catenin and IGF signaling were upregulated, whereas expression of several microRNAs decreased, particularly that of the miR-17-92 cluster. In primary astrocytic gliomas (n=82), expression of several members of miR-17-92 was significantly higher relative to those of normal brain (n=8) and significantly increased with tumor grade progression (P<0.05). A high-level amplification of the miR-17-92 locus was detected in one glioblastoma specimen. Transfection of inhibitors of miR-17-92 induced increased apoptosis and decreased cell proliferation in glioblastoma spheroids. Mir-17-92 inhibition was also associated with increased messenger RNA (mRNA) and/or protein expression of CDKN1A, E2F1, PTEN and CTGF. The CTGF gene was shown to be a target of miR-17-92 in glioblastoma spheroids by luciferase reporter assays. Our results suggest that miR-17-92 and its target CTGF mediate effects of differentiation-promoting treatment on glioblastoma cells through multiple regulatory pathways.


Brain Neoplasms/pathology , Connective Tissue Growth Factor/physiology , Glioblastoma/pathology , Spheroids, Cellular/pathology , Apoptosis Regulatory Proteins/genetics , Bcl-2-Like Protein 11 , Cell Differentiation , Cell Proliferation , Cell Survival , Connective Tissue Growth Factor/genetics , CpG Islands , Cyclin-Dependent Kinase Inhibitor p21/genetics , DNA Methylation , E2F1 Transcription Factor/genetics , Humans , Membrane Proteins/genetics , MicroRNAs , PTEN Phosphohydrolase/genetics , Proto-Oncogene Proteins/genetics , Signal Transduction
18.
Ann Oncol ; 21(8): 1636-1642, 2010 Aug.
Article En | MEDLINE | ID: mdl-20147743

BACKGROUND: A single-nucleotide polymorphism (SNP) in the FGFR4 gene is associated with poor prognosis in solid tumors. A recent study presented the first evidence that FGFR4 Arg388 could predict resistance to adjuvant chemotherapy in breast cancer. The present study evaluates the potential of this SNP to predict response to neoadjuvant chemotherapy (NCT) for primary breast cancer (PBC). METHODS: As part of a randomized phase II trial, 257 patients received either doxorubicin-cyclophosphamide (AC) or doxorubicin-pemetrexed (AP) followed by docetaxel (Doc; Taxotere) as NCT for T2-4/N0-2/M0 PBC. FGFR4 genotype analyzed on germline DNA was correlated with clinicopathologic variables, clinical response, and pathological complete response (pCR) using univariate and multivariate analyses. RESULTS: Only axillary lymph node status was associated with FGFR4 Arg388 [odds ratio (OR) 1.82, P = 0.03]. Joint analysis of both treatment arms revealed a correlation of FGFR4 Arg388 with clinical response (OR 2.14, P = 0.03) but not with pCR. In the AC-Doc arm, however, FGFR4 Arg388 was a strong predictor of pCR in the multivariate analysis (OR 3.79, P = 0.03). A significant interaction between FGFR4 genotype and treatment (P = 0.01) was found, indicating a therapy-specific effect. CONCLUSION: We provide the evidence that FGFR4 388Arg is an independent predictor of pCR following AC-Doc as NCT in PBC.


Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Arginine/genetics , Breast Neoplasms/genetics , Receptor, Fibroblast Growth Factor, Type 4/genetics , Adult , Aged , Arginine/chemistry , Base Sequence , Breast Neoplasms/drug therapy , Breast Neoplasms/pathology , Chemotherapy, Adjuvant , DNA Primers , Female , Genotype , Humans , Immunohistochemistry , Middle Aged , Prognosis , Receptor, Fibroblast Growth Factor, Type 4/chemistry , Remission Induction
19.
Article En | MEDLINE | ID: mdl-19963686

A positive impact on cardiac arrest survival has been demonstrated with the substantial reduction in time to defibrillation provided by the widespread deployment of automated external defibrillators (AEDs). However, recent studies have identified the importance of performing chest compressions before defibrillation in facilitating effective recovery from long duration ventricular fibrillation (VF). Despite the importance of cardiopulmonary resuscitation (CPR), effective performance of it in the field is hampered by many problems including the dependence on rescuer technique, which is known to be variable even with trained professionals. This research seeks to enhance survival outcomes following resuscitation. A full experimental system was developed that used an instrumented CPR manikin to provide interactive CPR coaching while collecting performance data. This system was utilized in a controlled human CPR performance study comparing the differences in chest compression performance with and without visual coaching and with and without interactive performance feedback coaching. Results from the human study support a number of conclusions and recommendations. In general using any type of coaching provided improvements in all of the CPR performance measures excluding chest recoil where there was a slight decrease in performance. The statistical results also indicated that the audio/visual coaching conditions provided a more effective coaching condition with respect to chest compression rate. Most notably, the feedback conditions both provided a statistically significant or trends toward improving chest compression effectiveness and produced superior performance as a whole.


Cardiopulmonary Resuscitation/education , Cardiopulmonary Resuscitation/methods , Defibrillators , Humans , Manikins , Software , Statistics as Topic
20.
Leukemia ; 23(11): 2018-26, 2009 Nov.
Article En | MEDLINE | ID: mdl-19641524

The two B-cell non-Hodgkin's lymphoma entities, chronic lymphocytic leukemia (CLL) and mantle cell lymphoma (MCL), show recurrent chromosomal gains of 3q25-q29, 12q13-q14 and 18q21-q22. The pathomechanisms affected by these aberrations are not understood. The aim of this study was to identify genes, located within these gained regions, which control cell death and cell survival of MCL and CLL cancer cells. Blood samples collected from 18 patients with CLL and 6 patients with MCL, as well as 6 cell lines representing both malignancies were analyzed by gene expression profiling. By a comparison of genomic DNA and gene expression, 72 candidate genes were identified. We performed a limited RNA interference screening with these candidates to identify genes affecting cell survival. CCDC50 (coiled coil domain containing protein 50), SERPINI2 and SMARCC2 mediated a reduction of cell viability in primary CLL cells as well as in cell lines. Gene knockdown and a nuclear factor kappa B (NFkappaB) reporter gene assay revealed that CCDC50 is required for survival in MCL and CLL cells and controls NFkappaB signaling.


Intracellular Signaling Peptides and Proteins/genetics , Leukemia, Lymphocytic, Chronic, B-Cell/genetics , Lymphoma, Mantle-Cell/genetics , RNA, Small Interfering , Bone Marrow Cells/cytology , Cell Line, Tumor , Cell Survival/physiology , DNA-Binding Proteins , Gene Expression Profiling , Gene Expression Regulation, Leukemic , Gene Expression Regulation, Neoplastic , Genetic Testing , Genomics , Humans , Intracellular Signaling Peptides and Proteins/chemistry , Kidney/cytology , Leukemia, Lymphocytic, Chronic, B-Cell/pathology , Lymphoma, Mantle-Cell/pathology , NF-kappa B/metabolism , Neoplasm Proteins/genetics , Protein Structure, Tertiary , Serpins/genetics , Transcription Factors/genetics , Transfection
...