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1.
RNA ; 2024 Apr 02.
Article in English | MEDLINE | ID: mdl-38565242

ABSTRACT

The stem loop 2 motif (s2m) in SARS-CoV-2 (SCoV-2) is located in the 3'-UTR. Although s2m has been reported to display characteristics of a mobile genomic element that might lead to an evolutionary advantage, its function has remained unknown. The secondary structure of the original SCoV-2 RNA sequence (Wuhan-Hu-1) was determined by NMR in late 2020, delineating the base pairing pattern and revealing substantial differences in secondary structure compared to SARS-CoV-1 (SCoV-1). The existence of a single G29742-A29756 mismatch in the upper stem of s2m leads to its destabilization and impedes a complete NMR analysis. With Delta, a variant of concern has evolved with one mutation compared to the original sequence that replaces G29742 by U29742. We show here that this mutation results in a more defined structure at ambient temperature accompanied by a rise in melting temperature. Consequently, we were able to identify over 90 % of the relevant NMR resonances using a combination of selective RNA labeling and filtered 2D NOESY as well as 4D NMR experiments. We present a comprehensive NMR analysis of the secondary structure, (sub-) nanosecond dynamics and ribose conformation of s2m Delta based on heteronuclear 13C NOE and T1 measurements and ribose carbon chemical shift-derived canonical coordinates. We further show that the G29742U mutation in Delta has no influence on the druggability of s2m compared to the Wuhan-Hu-1 sequence. With the assignment at hand, we identify the flexible regions of s2m as primary site for small molecule binding.

2.
Int J Mol Sci ; 21(3)2020 Feb 07.
Article in English | MEDLINE | ID: mdl-32046186

ABSTRACT

Bladder cancer is one of the more common malignancies in humans and the most expensive tumor for treating in the Unites States (US) and Europe due to the need for lifelong surveillance. Non-invasive tests approved by the FDA have not been widely adopted in routine diagnosis so far. Therefore, we aimed to characterize the two putative tumor suppressor genes ECRG4 and ITIH5 as novel urinary DNA methylation biomarkers that are suitable for non-invasive detection of bladder cancer. While assessing the analytical performance, a spiking experiment was performed by determining the limit of RT112 tumor cell detection (range: 100-10,000 cells) in the urine of healthy donors in dependency of the processing protocols of the RWTH cBMB. Clinically, urine sediments of 474 patients were analyzed by using quantitative methylation-specific PCR (qMSP) and Methylation Sensitive Restriction Enzyme (MSRE) qPCR techniques. Overall, ECRG4-ITIH5 showed a sensitivity of 64% to 70% with a specificity ranging between 80% and 92%, i.e., discriminating healthy, benign lesions, and/or inflammatory diseases from bladder tumors. When comparing single biomarkers, ECRG4 achieved a sensitivity of 73%, which was increased by combination with the known biomarker candidate NID2 up to 76% at a specificity of 97%. Hence, ITIH5 and, in particular, ECRG4 might be promising candidates for further optimizing current bladder cancer biomarker panels and platforms.


Subject(s)
Biomarkers, Tumor/urine , DNA Methylation , Proteinase Inhibitory Proteins, Secretory/genetics , Tumor Suppressor Proteins/genetics , Urinary Bladder Neoplasms/urine , Adult , Aged , Aged, 80 and over , Biomarkers, Tumor/genetics , Biomarkers, Tumor/standards , Cell Line, Tumor , Female , Humans , Limit of Detection , Male , Middle Aged , Proteinase Inhibitory Proteins, Secretory/standards , Reproducibility of Results , Tumor Suppressor Proteins/standards , Urinary Bladder Neoplasms/diagnosis
3.
J Cancer Res Clin Oncol ; 143(9): 1757-1769, 2017 Sep.
Article in English | MEDLINE | ID: mdl-28484844

ABSTRACT

PURPOSE: Cytokeratin 20 (CK20) and insulin-like growth factor 2 (IGF2) were previously proposed to be elevated in clinical samples from patients with bladder cancer (BCa). A two cohort design validation study was used to assess the relevance for BCa detection by transcript quantitation of both markers in urine samples. Their diagnostic value was assessed in comparison with voided urine cytology (VUC). METHODS: RNA isolation was carried out using cellular sediments of urine samples from 196/103 histologically positive BCa patients, as well as 97/50 control subjects for the test (TC) and validation cohort (VC), respectively. Urinary transcript levels of CK20 and IGF2 were determined by qPCR. RESULTS: Relative transcript levels were significantly elevated 3.4/11-fold for CK20 and 188/64-fold for IGF2 (p < 0.001) in urine sediments of BCa patients compared to controls in the TC and VC, respectively. In a combined analysis, the resulting sensitivity (SN) (SNTC: 77.9; SNVC: 90.3%) and specificity (SP) (SPTC: 88.0; SPVC: 84.0%) were similar to that of VUC. The sensitivity of VUC in combination with CK20 and IGF2 was considerably increased (SNTC: 94.6; SNVC: 93.2%) while specificity was reduced (SPTC: 72.0; SPVC: 82.0%) compared to VUC alone in the test and validation cohort. CONCLUSIONS: Transcript levels of IGF2 and CK20 enabled the detection of BCa with a diagnostic performance similar to VUC. Combined analysis of voided urine cytology together with altered transcript levels of CK20 and IGF2 enhanced sensitivity, but did not improve overall test performance.


Subject(s)
Biomarkers, Tumor/urine , Carcinoma, Transitional Cell/diagnosis , Insulin-Like Growth Factor II/urine , Urinary Bladder Neoplasms/diagnosis , Adult , Aged , Aged, 80 and over , Carcinoma, Transitional Cell/urine , Cohort Studies , Female , Humans , Keratin-20/urine , Male , Middle Aged , Sensitivity and Specificity , Urinary Bladder Neoplasms/urine
4.
Vaccine ; 35(5): 814-820, 2017 02 01.
Article in English | MEDLINE | ID: mdl-28049587

ABSTRACT

All patients with advanced chronic kidney disease or on renal replacement therapy should receive active hepatitis B vaccination. The aim of this retrospective cohort study was to investigate the association between the immune response to hepatitis B vaccination and all-cause, cardiovascular or infection-related mortality in incident dialysis patients starting dialysis between 2001 and 2008 (n=426) in two Austrian dialysis centers. Vaccination response was defined as follows: absent anti-HBs antibody titer or a titer <10IU/L was classified as non-response, seroconversion (SC) was defined as a titer ⩾10IU/L, and seroprotection (SP) as a titer ⩾100IU/L. Kaplan-Meier survival curves and multivariable adjusted Cox Proportional Hazards Models were used to determine the association between vaccination response and all-cause, cardiovascular and infection-related mortality. Of all patients 207 (48.6%) were non-responders, SC was observed in 219 (51.4%), SP in 118 (27.7%) patients. During a median follow-up of 51.2 months 228 (53.5%) patients died. Patients with SP and SC showed a significantly lower all-cause (p<0.001 for both) and cardiovascular mortality (p=0.006 for SP, p=0.01 for SC). SP and SC were independently associated with a significant risk reduction for all-cause mortality (SP: HR 0.69, 95% CI 0.49-0.97, p=0.03; SC: HR 0.72, 95% CI 0.55-0.95, p=0.02). In conclusion, achieving seroconversion and seroprotection after active hepatitis B vaccination is associated with significantly reduced all-cause mortality in incident dialysis patients. This simple and readily available tool allows estimation of patient survival independently of other well-known key parameters such as age, gender, the presence of diabetes and markers of malnutrition and inflammation.


Subject(s)
Hepatitis B Antibodies/biosynthesis , Hepatitis B Vaccines/administration & dosage , Hepatitis B virus/drug effects , Hepatitis B/prevention & control , Renal Dialysis , Vaccination , Aged , Female , Hepatitis B/immunology , Hepatitis B/mortality , Hepatitis B/virology , Hepatitis B virus/immunology , Humans , Kaplan-Meier Estimate , Male , Middle Aged , Proportional Hazards Models , Renal Insufficiency, Chronic/mortality , Renal Insufficiency, Chronic/pathology , Renal Insufficiency, Chronic/physiopathology , Renal Insufficiency, Chronic/therapy , Retrospective Studies
5.
Genes Chromosomes Cancer ; 52(3): 265-73, 2013 Mar.
Article in English | MEDLINE | ID: mdl-23125027

ABSTRACT

PARK2 is an E3 ligase, known to be involved in ubiquitination of several proteins and to play a role in neuronal protection. The gene PARK2 and its potentially co-regulated gene PACRG have been previously found to be deleted in clear-cell renal cell carcinomas (ccRCCs). The aim of our study was to evaluate the mRNA and protein expression of PARK2 and PACRG in a large cohort of ccRCC, and to investigate their association with outcome. The expression of both genes was measured by quantitative PCR in 94 primary ccRCCs and autologous nonmalignant kidney tissues. PACRG and PARK2 protein expression was determined immunohistochemically using tissue microarrays comprising 133 ccRCCs. The mRNA and protein expression of PARK2 and PACRG was significantly downregulated in ccRCCs compared with nonmalignant tissues. Low levels of PARK2 mRNA were associated with high-grade ccRCC and lymph node metastasis. Patients with low PARK2 mRNA levels showed a higher tumor-specific mortality rate and a shorter overall survival (OS) than those with high PARK2 expression. Patients without PACRG mRNA expression in the tumor had a shorter disease-free survival and OS than those with tumors expressing PACRG. In multivariate analyses, neither PARK2 nor PACRG expression were independent prognostic factors. The protein expression of PARK2 and PACRG was significantly downregulated in ccRCCs (82.8, and 96.9%, respectively), but no association with clinical outcome was noticed.


Subject(s)
Carcinoma, Renal Cell/genetics , Carcinoma, Renal Cell/pathology , Gene Expression Regulation, Neoplastic , Kidney Neoplasms/genetics , Molecular Chaperones/genetics , Ubiquitin-Protein Ligases/genetics , Adult , Aged , Carcinoma, Renal Cell/mortality , Disease Progression , Female , Gene Expression Profiling , Humans , Kidney Neoplasms/mortality , Kidney Neoplasms/pathology , Male , Microfilament Proteins , Middle Aged , Molecular Chaperones/metabolism , Neoplasm Staging , RNA, Messenger/genetics , RNA, Messenger/metabolism , Ubiquitin-Protein Ligases/metabolism
7.
Neurol Res ; 33(6): 638-55, 2011 Jul.
Article in English | MEDLINE | ID: mdl-21708074

ABSTRACT

BACKGROUND: The heteroplasmic mitochondrial DNA (mtDNA) mutation A3243G causes the mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes (MELAS) syndrome as one of the most frequent mitochondrial diseases. The process of reconfiguration of nuclear gene expression profile to accommodate cellular processes to the functional status of mitochondria might be a key to MELAS disease manifestation and could contribute to its diverse phenotypic presentation. OBJECTIVE: To determine master regulatory protein networks and disease-modifying genes in MELAS syndrome. METHODS: Analyses of whole blood transcriptomes from 10 MELAS patients using a novel strategy by combining classic Affymetrix oligonucleotide microarray profiling with regulatory and protein interaction network analyses. RESULTS: Hierarchical cluster analysis elucidated that the relative abundance of mutant mtDNA molecules is decisive for the nuclear gene expression response. Further analyses confirmed not only transcription factors already known to be involved in mitochondrial diseases (such as TFAM), but also detected the hypoxia-inducible factor 1 complex, nuclear factor Y and cAMP responsive element-binding protein-related transcription factors as novel master regulators for reconfiguration of nuclear gene expression in response to the MELAS mutation. Correlation analyses of gene alterations and clinico-genetic data detected significant correlations between A3243G-induced nuclear gene expression changes and mutant mtDNA load as well as disease characteristics. These potential disease-modifying genes influencing the expression of the MELAS phenotype are mainly related to clusters primarily unrelated to cellular energy metabolism, but important for nucleic acid and protein metabolism, and signal transduction. DISCUSSION: Our data thus provide a framework to search for new pathogenetic concepts and potential therapeutic approaches to treat the MELAS syndrome.


Subject(s)
Gene Expression Profiling/methods , Gene Regulatory Networks/genetics , Genome-Wide Association Study/methods , MELAS Syndrome/blood , MELAS Syndrome/genetics , Adult , Female , Humans , Male , Middle Aged , Mutation/genetics , Protein Array Analysis/methods , Young Adult
8.
Biosens Bioelectron ; 26(4): 1543-7, 2010 Dec 15.
Article in English | MEDLINE | ID: mdl-20729067

ABSTRACT

We report on the development of a new platform technology for the detection of genetic variations by means of surface plasmon resonance (SPR) spectroscopy. TOPAS chips with integrated optics were exploited in combination with microfluidics. Within minutes, the detection of hybridization kinetics was achieved simultaneously at all spots of the DNA microarray. A nanoliter dispenser is used to deposit thiol-modified single-stranded probe DNA on the gold surface of the chips. We investigated the influence of different parameters on hybridization using model polymerase chain reaction (PCR) products. These PCR products comprised a single-stranded tag sequence being complementary to an anti-tag sequence of probes immobilized on the gold surface. The signals increased with increasing length of PCR products (60, 100 or 300 base pairs) as well as with their concentration. We investigated hybridizations on DNA microarrays comprising 90 spots of probe DNA with three different sequences. Furthermore, we demonstrate that sequences with possible hairpin structures significantly lower the binding rate, and thus, the SPR signals during hybridization.


Subject(s)
Oligonucleotide Array Sequence Analysis/instrumentation , Surface Plasmon Resonance/instrumentation , Base Sequence , DNA Probes/chemistry , DNA Probes/genetics , Nucleic Acid Conformation , Nucleic Acid Hybridization , Oligonucleotide Array Sequence Analysis/methods , Polymerase Chain Reaction , Surface Plasmon Resonance/methods
9.
Exp Cell Res ; 316(17): 2760-78, 2010 Oct 15.
Article in English | MEDLINE | ID: mdl-20599952

ABSTRACT

Tissue-specific stem cells, such as bone-marrow-derived human mesenchymal stem cells (hMSCs), are thought to be lineage restricted and therefore, could only be differentiated into cell types of the tissue of origin. Several recent studies however have suggested that these types of stem cells might be able to break barriers of germ layer commitment and differentiate in vitro into cells with neuroectodermal properties. We reported earlier about efficient conversion of adult hMSCs into a neural stem cell (NSC)-like population (hmNSCs, for human marrow-derived NSC-like cells) with all major properties of NSCs including functional neuronal differentiation capacity. Here we compared the transcriptomes from hMSCs and hmNSCs using a novel strategy by combining classic Affymetrix oligonucleotide microarray profiling with regulatory and protein interaction network analyses to shed light on regulatory protein networks involved in this neuroectodermal conversion process. We found differential regulation of extracellular matrix protein transcripts, up-regulation of distinct neuroectodermal and NSCs marker genes and local chromosomal transcriptional up-regulation at chromosome 4q13.3. In comparison to hMSCs and primary adult hippocampal NSCs, the transcriptome of hmNSCs displayed minor overlap with both other cell populations. Advanced bioinformatics of regulated genes upon neuroectodermal conversion identified transcription factor networks with HIF-1 and microRNA miR-124a as potential major regulators. Together, transgerminal neuroectodermal conversion of hMSCs into NSC-like cells is accompanied by extensive changes of their global gene expression profile, which might be controlled in part by transcription factor networks related to HIF-1 and miR-124a.


Subject(s)
Gene Expression Profiling , Gene Regulatory Networks , Genome, Human , Hypoxia-Inducible Factor 1/genetics , Mesenchymal Stem Cells/cytology , MicroRNAs/genetics , Neural Plate/cytology , Adolescent , Adult , Bone Marrow Cells , Cell Lineage , Cells, Cultured , Humans , Neurons/cytology , Stem Cells/cytology , Young Adult
10.
Int J Cancer ; 125(2): 474-82, 2009 Jul 15.
Article in English | MEDLINE | ID: mdl-19391132

ABSTRACT

Our understanding of metastatic spread is limited and molecular mechanisms causing particular characteristics of metastasis are largely unknown. Herein, transcriptome-wide expression profiles of a unique cohort of 20 laser-resected pulmonary metastases (Mets) of 18 patients with clear-cell renal cell carcinoma (RCC) were analyzed to identify expression patterns associated with two important prognostic factors in RCC: the disease-free interval (DFI) after nephrectomy and the number of Mets per patient. Differentially expressed genes were identified by comparing early (DFI < or = 9 months) and late (DFI > or = 5 years) Mets, and Mets derived from patients with few (< or =8) and multiple (> or =16) Mets. Early and late Mets could be separated by the expression of genes involved in metastasis-associated processes, such as angiogenesis, cell migration and adhesion (e.g., PECAM1, KDR). Samples from patients with multiple Mets showed an elevated expression of genes associated with cell division and cell cycle (e.g., PBK, BIRC5, PTTG1) which indicates that a high number of Mets might result from an increased growth potential. Minimal sets of genes for the prediction of the DFI and the number of Mets per patient were identified. Microarray results were confirmed by quantitative PCR by including nine further pulmonary Mets of RCC. In summary, we showed that subgroups of Mets are distinguishable based on their expression profiles, which reflect the DFI and the number of Mets of a patient. To what extent the identified molecular factors contribute to the development of these characteristics of metastatic spread needs to be analyzed in further studies.


Subject(s)
Carcinoma, Renal Cell/pathology , Kidney Neoplasms/pathology , Lung Neoplasms/genetics , Neoplasm Metastasis , Adult , Aged , Disease-Free Survival , Female , Humans , Lung Neoplasms/secondary , Male , Middle Aged , Polymerase Chain Reaction , Tissue Array Analysis
11.
Neoplasia ; 10(7): 634-42, 2008 Jul.
Article in English | MEDLINE | ID: mdl-18592004

ABSTRACT

Genetic aberrations are crucial in renal tumor progression. In this study, we describe loss of heterozygosity (LOH) and DNA-copy number abnormalities in clear cell renal cell carcinoma (cc-RCC) discovered by genome-wide single nucleotide polymorphism (SNP) arrays. Genomic DNA from tumor and normal tissue of 22 human cc-RCCs was analyzed on the Affymetrix GeneChip Human Mapping 10K Array. The array data were validated by quantitative polymerase chain reaction and immunohistochemistry. Reduced DNA copy numbers were detected on chromosomal arm 3p in 91%, on chromosome 9 in 32%, and on chromosomal arm 14q in 36% of the tumors. Gains were detected on chromosomal arm 5q in 45% and on chromosome 7 in 32% of the tumors. Copy number abnormalities were found not only in FHIT and VHL loci, known to be involved in renal carcinogenesis, but also in regions containing putative new tumor suppressor genes or oncogenes. In addition, microdeletions were detected on chromosomes 1 and 6 in genes with unknown impact on renal carcinogenesis. In validation experiments, abnormal protein expression of FOXP1 (on 3p) was found in 90% of tumors (concordance with SNP array data in 85%). As assessed by quantitative polymerase chain reaction, PARK2 and PACRG were down-regulated in 57% and 100%, respectively, and CSF1R was up-regulated in 69% of the cc-RCC cases (concordance with SNP array data in 57%, 33%, and 38%). Genome-wide SNP array analysis not only confirmed previously described large chromosomal aberrations but also detected novel microdeletions in genes potentially involved in tumor genesis of cc-RCC.


Subject(s)
Carcinoma, Renal Cell/genetics , Chromosome Aberrations , Chromosome Mapping/methods , Gene Dosage , Kidney Neoplasms/genetics , Loss of Heterozygosity , Oligonucleotide Array Sequence Analysis/methods , Polymorphism, Single Nucleotide , Adult , Aged , Aged, 80 and over , Case-Control Studies , Chromosome Mapping/instrumentation , Chromosomes, Human , Chromosomes, Human, Pair 3 , Female , Humans , Male , Middle Aged
12.
Hum Pathol ; 39(11): 1621-9, 2008 Nov.
Article in English | MEDLINE | ID: mdl-18656243

ABSTRACT

Tubular breast carcinoma is a highly differentiated carcinoma with an excellent prognosis. Distinct genetic alterations in tubular breast carcinoma cells have been described, especially broad genetic losses on the q-arm of chromosome 16. These are more common in lobular breast carcinoma and low-grade ductal carcinoma in situ than in ductal breast carcinoma and high-grade ductal carcinoma in situ. To further delineate the molecular changes involved in tubular breast carcinoma more precisely, we examined 23 formalin-fixed and paraffin wax-embedded tissue samples (21 of tubular breast carcinoma and 2 of nonneoplastic breast epithelium) by microarray-based comparative genomic hybridization focusing on 287 genomic target clones of oncogenes and tumor suppressor genes. The results obtained from all nonneoplastic tissue samples of breast epithelium indicate no DNA copy number changes. In the tubular breast carcinoma samples, the highest frequencies for DNA sequence copy number losses were detected for CDH13 (in 86% of the samples) and MSH2, KCNK12 (in 52% of the samples). The highest frequencies of DNA sequence copy number gains were detected for HRAS and D13S319XYZ (each in 62% of the samples). Using principal component analysis, 3 subgroups of tubular breast carcinomas showing relative genetic changes were identified. For validation, the most frequent DNA copy number loss for CDH13 (18/21) was confirmed using fluorescence in situ hybridization in 4 of 5 tubular breast carcinomas analyzed. The newly identified genes with considerable copy number changes may include so far unknown candidate genes for the development and progression of tubular breast carcinoma, such as CDH13. The study provides the starting point for further delineating their detailed influence on the pathogenesis of tubular breast carcinoma.


Subject(s)
Breast Neoplasms/genetics , Cadherins/genetics , Carcinoma, Ductal, Breast/genetics , Chromosomes, Human, Pair 16 , Biomarkers, Tumor/genetics , Carcinoma, Lobular/genetics , Comparative Genomic Hybridization , Female , Humans , In Situ Hybridization, Fluorescence , Microarray Analysis , Microscopy, Fluorescence
13.
Int J Cancer ; 123(6): 1433-8, 2008 Sep 15.
Article in English | MEDLINE | ID: mdl-18561322

ABSTRACT

Intensive lymph node involvement indicates poor prognosis in breast cancer patients. The significance of other molecular prognostic factors in this subgroup is unclear. Karyopherin alpha2 (KPNA2) has been reported as an important factor of tumorgenesis and progression of breast cancer. The aim of present study was to evaluate the impact of KPNA2 expression on prognosis of patients with high risk breast cancer (HRBC) and response intensive chemotherapy within the randomized WSG-AM-01 trial. KPNA2 nuclear expression (>10% vs. <10% of nuclei) was measured by immunohistochemistry on tissue arrays of 191 patients randomized to tandem high dose vs. conventional dose-dense chemotherapy in HRBC with >9 positive lymph nodes and correlated with clinical outcome (median follow-up of 63.3 months) by Kaplan-Meier and multivariate Cox hazard model analysis, including, molecular subtypes determined by k-clustering (k = 5). KPNA2 overexpression (n = 74, 39%) significantly correlated with shorter event-free and overall survival (OS) in both therapy arms by univariate analysis. Multivariate analysis showed that the overexpression of KPNA2 was an independent prognostic factor of decreased OS HR = 1.86 [95% CI: 1.07-3.23, p = 0.03]. This predictive value was independent of basal-like/Her-2/neu subtypes, significantly associated with KPNA2 and was addressed particularly to G2 tumors. Our data suggest the use of KPNA2 nuclear expression as novel prognostic marker in node-positive patients, especially in determination of G2 tumors in 2 subgroups of different prognosis. KPNA2 expression may be also considered as a marker for global chemoresistance, which can not be overcome by conventional dose-modification of chemotherapy in advanced breast cancer.


Subject(s)
Biomarkers, Tumor/analysis , Breast Neoplasms/metabolism , Breast Neoplasms/mortality , alpha Karyopherins/biosynthesis , Antineoplastic Combined Chemotherapy Protocols/administration & dosage , Breast Neoplasms/drug therapy , Cell Nucleus/metabolism , Dose-Response Relationship, Drug , Female , Humans , Immunohistochemistry , Kaplan-Meier Estimate , Lymphatic Metastasis/pathology , Middle Aged , Prognosis , Randomized Controlled Trials as Topic , Receptor, ErbB-2/genetics , Receptor, ErbB-2/metabolism , Tissue Array Analysis
14.
Biomaterials ; 29(3): 302-13, 2008 Jan.
Article in English | MEDLINE | ID: mdl-17935776

ABSTRACT

Biomaterials are used in tissue engineering with the aim to repair or reconstruct tissues and organs. Frequently, the identification and development of biomaterials is an iterative process with biomaterials being designed and then individually tested for their properties in combination with one specific cell type. However, recent efforts have been devoted to systematic, combinatorial and parallel approaches to identify biomaterials, suitable for specific applications. Embryonic and adult stem cells represent an ideal cell source for tissue engineering. Since stem cells can be readily isolated, expanded and transplanted, their application in cell-based therapies has become a major focus of research. Biomaterials can potentially influence e.g. stem cell proliferation and differentiation in both, positive or negative ways and biomaterial characteristics have been applied to repel or attract stem cells in a niche-like microenvironment. Our consortium has now established a grid-based platform to investigate stem cell/biomaterial interactions. So far, we have assessed 140 combinations of seven different stem cell types and 19 different polymers performing systematic screening assays to analyse parameters such as morphology, vitality, cytotoxicity, apoptosis, and proliferation. We thus can suggest and advise for and against special combinations for stem cell-based tissue engineering.


Subject(s)
Biocompatible Materials/pharmacology , Mesenchymal Stem Cells/cytology , Mesenchymal Stem Cells/drug effects , Tissue Engineering/methods , Animals , Biocompatible Materials/metabolism , Biocompatible Materials/toxicity , Cell Shape/drug effects , Cell Survival/drug effects , Cells, Cultured , Cluster Analysis , Female , Hot Temperature , Humans , Mice , Microscopy, Atomic Force , Microscopy, Electron, Scanning
15.
Stem Cells ; 25(5): 1231-40, 2007 May.
Article in English | MEDLINE | ID: mdl-17218394

ABSTRACT

Global gene expression profiling was performed using RNA from adult human hippocampus-derived neuroprogenitor cells (NPCs) and multipotent frontal cortical fetal NPCs compared with adult human mesenchymal stem cells (hMSCs) as a multipotent adult stem cell control, and adult human hippocampal tissue, to define a gene expression pattern that is specific for human NPCs. The results were compared with data from various databases. Hierarchical cluster analysis of all neuroectodermal cell/tissue types revealed a strong relationship of adult hippocampal NPCs with various white matter tissues, whereas fetal NPCs strongly correlate with fetal brain tissue. However, adult and fetal NPCs share the expression of a variety of genes known to be related to signal transduction, cell metabolism and neuroectodermal tissue. In contrast, adult NPCs and hMSCs overlap in the expression of genes mainly involved in extracellular matrix biology. We present for the first time a detailed transcriptome analysis of human adult NPCs suggesting a relationship between hippocampal NPCs and white matter-derived precursor cells. We further provide a framework for standardized comparative gene expression analysis of human brain-derived NPCs with other stem cell populations or differentiated tissues. Disclosure of potential conflicts of interest is found at the end of this article.


Subject(s)
Fetus/cytology , Fetus/metabolism , Gene Expression Profiling , Neurons/cytology , Stem Cells/cytology , Stem Cells/metabolism , Transcription, Genetic , Adolescent , Adult , Biomarkers/metabolism , Cell Differentiation , Cluster Analysis , Female , Hippocampus/metabolism , Humans , Male , Mesenchymal Stem Cells/cytology , Mesenchymal Stem Cells/metabolism , Mesoderm/cytology , Mesoderm/metabolism
16.
Clin Cancer Res ; 13(2 Pt 1): 488-97, 2007 Jan 15.
Article in English | MEDLINE | ID: mdl-17255270

ABSTRACT

PURPOSE: To characterize the prognostic and predictive impact of protein expression profiles in high-risk breast cancer patients who had previously been shown to benefit from high-dose chemotherapy (HDCT) in comparison to dose-dense chemotherapy (DDCT). EXPERIMENTAL DESIGN: The expression of 34 protein markers was evaluated using tissue microarrays containing paraffin-embedded breast cancer samples from 236 patients who were randomized to the West German Study Group AM01 trial. RESULTS: (a) 24 protein markers of the initial panel of 34 markers were sufficient to identify five profile clusters (subtypes) by K-means clustering: luminal-A (27%), luminal-B (12%), HER-2 (21%), basal-like (13%) cluster, and a so-called "multiple marker negative" (MMN) cluster (27%) characterized by the absence of specifying markers. (b) After DDCT, HER-2 and basal-like groups had significantly worse event-free survival [EFS; hazard ratio (HR), 3.6 [95% confidence interval (95% CI), 1.65-8.18; P = 0.001] and HR, 3.7 (95% CI, 1.68-8.48; P < 0.0001), respectively] when compared with both luminal groups. (c) After HDCT, the HR was 1.5 (95% CI, 0.76-3.05) for EFS in the HER-2 subgroup and 1.1 (95% CI, 0.37-3.32) in the basal-like subgroup, which indicates a better outcome for patients in the HER-2 and basal-like subgroups who received HDCT. The MMN cluster showed a trend to a better EFS after HDCT compared with DDCT. CONCLUSIONS: Protein expression profiling in high-risk breast cancers identified five subtypes, which differed with respect to survival and response to chemotherapy: In contrast to luminal-A and luminal-B subtypes, HER-2 and basal-like subgroups had a significant predictive benefit, and the MMN cluster had a trend to a predictive benefit, both from HDCT when compared with DDCT.


Subject(s)
Gene Expression Profiling/methods , Gene Expression Regulation, Neoplastic , Adult , Aged , Antineoplastic Agents/pharmacology , Biomarkers, Tumor , Cluster Analysis , Disease-Free Survival , Female , Germany , Humans , Middle Aged , Oligonucleotide Array Sequence Analysis , Prognosis , Risk
17.
Int J Cancer ; 119(6): 1276-84, 2006 Sep 15.
Article in English | MEDLINE | ID: mdl-16615118

ABSTRACT

The human telomerase reverse transcriptase (hTERT) contributes to the immortal phenotype of the majority of cancers. Targeting hTERT by transfection with antisense oligonucleotides (AS-ODNs) induced immediate growth inhibition in human bladder cancer (BCa) cells. The molecular basis of the antiproliferative capacity of hTERT AS-ODNs was investigated by oligonucleotide microarray analyses and was compared to effects caused by siRNA-mediated knock-down of hTERT in EJ28 BCa cells. Two different AS-ODNs -- both down-regulated the expression of hTERT -- changed the expression of different genes mainly involved in stress response (including EGR1, ATF3 and GDF15), but without an association to telomerase function. This indicates that the immediate growth inhibition was caused, at least in part, by off-target effects. In comparison to that the blockade of the expression of hTERT using 2 different siRNAs was accompanied by the down-regulation of the oncogenes FOS-like antigen 1 (FOSL1) and epidermal growth factor receptor (EGFR), known to be overexpressed in BCa. We show here for the first time that repression of the hTERT transcript number decreased the expression of EGFR both at the mRNA and protein levels, suggesting a potential new function of hTERT in the regulation of EGFR-stimulated proliferation. Furthermore, the suppression of hTERT by siRNAs caused an enhancement of the antiproliferative capacity of the chemotherapeutics mitomycin C and cisplatin. The results presented herein may support the hypothesis that hTERT promotes the growth of tumor cells by mechanisms independent from telomere lengthening. The detailed clarification of these processes will shed light on the question, whether telomerase inhibitors might constitute suitable anticancer tools.


Subject(s)
DNA-Binding Proteins/antagonists & inhibitors , ErbB Receptors/metabolism , Gene Expression Profiling , RNA, Small Interfering/pharmacology , Telomerase/antagonists & inhibitors , Urinary Bladder Neoplasms/metabolism , DNA-Binding Proteins/genetics , DNA-Binding Proteins/metabolism , Down-Regulation , Humans , Microarray Analysis , Oligonucleotide Array Sequence Analysis , RNA, Messenger/genetics , RNA, Messenger/metabolism , Telomerase/genetics , Telomerase/metabolism , Tumor Cells, Cultured
18.
Eur J Med Genet ; 48(3): 328-38, 2005.
Article in English | MEDLINE | ID: mdl-16179228

ABSTRACT

A 5.4-year-old male propositus is reported with mild dysmorphic features including hypoplasia of the radial part of both hands affecting thenar, thumb and fingers 2-3, incomplete syndactyly of fingers 3-4, single palmar creases, brachymesophalangia of toes 3-5, dissociated retardation of bone age, telecanthus, spina bifida occulta, cryptorchidism, muscular hypotonia, and borderline mental retardation. His karyotype was unbalanced, 46,XY,der(16)ins(4;16)(q26q28.1; q12.1q12.2)pat. In the propositus' father who had brachydactyly of fingers 2-5 and brachymesophalangia of toes 3-5 the insertion was reciprocal, 46,XY,rep ins(4;16)(q26q28.1;q12.1q12.2). Insertions are rare, reciprocal insertions most unusual. The characterization of the insertion in the propositus and the detection of its reciprocity in the father were achieved by the application of spectral karyotyping (SKY). Further examination of the propositus' unbalanced genome by array-CGH analysis delimited the chromosomal locations of the deletion/insertion rearrangement on a 0.5-2 Mb resolution level and allowed to design specific BAC FISH analyses that pinpointed the borders of the affected segments. The rearrangement involved a segment of 7.7 Mb between RP11-1030 g22 and RP11-52k8 at the chromosomal regions 4q26 and 4q28.1, respectively, and a segment of 2.8 Mb between RP11-242n20 at 16q12.1 and RP11-324d17 at 16q12.2. A simple molecular genetic explanation of the phenotype cannot be given. A relation to the Townes Brocks gene (SALL1) located 340 kb proximal of the 16q12 deletion/insertion is unlikely. Possibly more relevant is an overlap of the 16q12 deletion/insertion with a small deletion of the syntenic chromosomal region in the mouse that causes a developmental disorder of digits ("Fused toes").


Subject(s)
Chromosomes, Human, Pair 16/genetics , Limb Deformities, Congenital/genetics , Oligonucleotide Array Sequence Analysis/methods , Spectral Karyotyping , Translocation, Genetic , Child , Child, Preschool , Chromosomes, Artificial, Bacterial , Humans , In Situ Hybridization, Fluorescence , Limb Deformities, Congenital/diagnosis , Male
19.
Clin Cancer Res ; 11(12): 4415-29, 2005 Jun 15.
Article in English | MEDLINE | ID: mdl-15958626

ABSTRACT

PURPOSE: The aim of the present study was to define gene expression profiles of noninvasive and invasive bladder cancer, to identify potential therapeutic or screening targets in bladder cancer, and to define genetic changes relevant for tumor progression of recurrent papillary bladder cancer (pTa). EXPERIMENTAL DESIGN: Overall, 67 bladder neoplasms (46 pTa, 3 pTis, 10 pT1, and 8 pT2) and eight normal bladder specimens were investigated by a combination of laser microdissection and gene expression profiling. Eight of 16 patients with recurrent noninvasive papillary bladder tumors developed carcinoma in situ (pTis) or invasive bladder cancer (> or = pT1G2) in the course of time. RNA expression results of the putative progression marker cathepsin E (CTSE) were confirmed by immunohistochemistry using high-throughput tissue microarray analysis (n = 776). Univariate analysis of factors regarding overall survival, progression-free survival, and recurrence-free survival in patients with urothelial bladder cancer was done. RESULTS: Hierarchical cluster analyses revealed no differences between pTaG1 and pTaG2 tumors. However, distinct groups of invasive cancers with different gene expression profiles in papillary and solid tumors were found. Progression-associated gene profiles could be defined (e.g., FABP4 and CTSE) and were already present in the preceding noninvasive papillary tumors. CTSE expression (P = 0.003) and a high Ki-67 labeling index of at least 5% (P = 0.01) were the only factors that correlated significantly with progression-free survival of pTa tumors in our gene expression approach. CONCLUSIONS: Gene expression profiling revealed novel genes with potential clinical utility to select patients that are more likely to develop aggressive disease.


Subject(s)
Carcinoma, Papillary/pathology , Gene Expression Profiling , Urinary Bladder Neoplasms/pathology , Aged , Analysis of Variance , Carcinoma, Papillary/genetics , Carcinoma, Papillary/metabolism , Cathepsin E/genetics , Cathepsin E/metabolism , Cluster Analysis , Disease Progression , Female , Gene Expression Regulation, Neoplastic/genetics , Humans , Immunohistochemistry , Lasers , Male , Microdissection , Middle Aged , Neoplasm Invasiveness , Neoplasm Recurrence, Local , Oligonucleotide Array Sequence Analysis , Survival Analysis , Urinary Bladder Neoplasms/genetics , Urinary Bladder Neoplasms/metabolism
20.
Genomics ; 85(3): 392-400, 2005 Mar.
Article in English | MEDLINE | ID: mdl-15718106

ABSTRACT

Array-based comparative genome hybridization is a powerful tool for detecting chromosomal imbalances at high resolution. However, the design and setup of such arrays are time consuming and expensive and thus worthwhile only when large numbers of arrays will be processed. To provide a feasible solution, we have developed an algorithm that renders the publicly available Affymetrix 10K SNP genotyping chip useful for high-resolution analysis of chromosomal imbalances. We have used our newly developed algorithm to analyze data from Affymetrix 10K chips that were hybridized with DNA probes from a variety of different sources, such as primary tumors, cell lines, and blood from patients with unbalanced translocations. In summary, we were able to (i) demonstrate the capability of our method by reproduction of published and unpublished data obtained with alternative methods and (ii) identify novel imbalances that were not shown before.


Subject(s)
Oligonucleotide Array Sequence Analysis , Polymorphism, Single Nucleotide , Algorithms , Chromosomes, Artificial, Bacterial , Genotype , Heterozygote
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