10 results on '"Unger, Kristian"'
Search Results
2. Independent Validation of Candidate Genes Identified after a Whole Genome Screening on Mayak Workers Exposed to Prolonged Occupational Radiation
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Abend, Michael, Azizova, Tamara, Müller, Kerstin, Dörr, Harald, Senf, Sven, Kreppel, Helmut, Rusinova, Galina, Glazkova, Irina, Vyazovskaya, Natalia, Unger, Kristian, and Meineke, Viktor
- Published
- 2014
3. Integration of p16/HPV DNA Status with a 24-miRNA-Defined Molecular Phenotype Improves Clinically Relevant Stratification of Head and Neck Cancer Patients.
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Hess, Julia, Unger, Kristian, Maihoefer, Cornelius, Schüttrumpf, Lars, Weber, Peter, Marschner, Sebastian, Wintergerst, Ludmila, Pflugradt, Ulrike, Baumeister, Philipp, Walch, Axel, Woischke, Christine, Kirchner, Thomas, Werner, Martin, Sörensen, Kristin, Baumann, Michael, Tinhofer, Ingeborg, Combs, Stephanie E., Debus, Jürgen, Schäfer, Henning, and Krause, Mechthild
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DNA analysis , *PAPILLOMAVIRUSES , *MICRORNA , *HEAD & neck cancer , *REGRESSION analysis , *ESTROGEN , *WNT proteins , *CANCER patients , *ADJUVANT treatment of cancer , *CHEMORADIOTHERAPY , *CELLULAR signal transduction , *RISK assessment , *GENE expression profiling , *DESCRIPTIVE statistics , *DECISION making in clinical medicine , *PHENOTYPES , *LONGITUDINAL method - Abstract
Simple Summary: Human papillomavirus (HPV)-driven head and neck squamous cell carcinomas (HNSCC), regarded as a distinct clinical entity, are characterized by a considerably favourable prognosis after radio(chemo)therapy and a not yet fully understood distinct molecular pathogenesis. We aimed to develop a miRNA-signature that identifies HPV-associated HNSCC according to their specific molecular pathogenesis, and to characterise the transcriptome compared to HPV-negative HNSCC. We performed miRNA expression profiling of n = 229 HPV characterized HNSCC specimens of patients treated by adjuvant radio(chemo) therapy. Using lasso-regression, a 24-miRNA signature predicting HPV-status was built in a multicentre cohort and validated in a single-centre cohort. Its combination with p16/HPV DNA status improved clinically relevant risk stratification, allowed the identification of an HPV-associated patient subgroup with impaired overall survival, and might be considered for future clinical decision-making. miRNA-transcriptome integration identified HPV-specific signaling pathways. Human papillomavirus (HPV)-driven head and neck squamous cell carcinomas (HNSCC) generally have a more favourable prognosis. We hypothesized that HPV-associated HNSCC may be identified by an miRNA-signature according to their specific molecular pathogenesis, and be characterized by a unique transcriptome compared to HPV-negative HNSCC. We performed miRNA expression profiling of two p16/HPV DNA characterized HNSCC cohorts of patients treated by adjuvant radio(chemo)therapy (multicentre DKTK-ROG n = 128, single-centre LMU-KKG n = 101). A linear model predicting HPV status built in DKTK-ROG using lasso-regression was tested in LMU-KKG. LMU-KKG tumours (n = 30) were transcriptome profiled for differential gene expression and miRNA-integration. A 24-miRNA signature predicted HPV-status with 94.53% accuracy (AUC: 0.99) in DKTK-ROG, and 86.14% (AUC: 0.86) in LMU-KKG. The prognostic values of 24-miRNA- and p16/HPV DNA status were comparable. Combining p16/HPV DNA and 24-miRNA status allowed patient sub-stratification and identification of an HPV-associated patient subgroup with impaired overall survival. HPV-positive tumours showed downregulated MAPK, Estrogen, EGFR, TGFbeta, WNT signaling activity. miRNA-mRNA integration revealed HPV-specific signaling pathway regulation, including PD−L1 expression/PD−1 checkpoint pathway in cancer in HPV-associated HNSCC. Integration of clinically established p16/HPV DNA with 24-miRNA signature status improved clinically relevant risk stratification, which might be considered for future clinical decision-making with respect to treatment de-escalation in HPV-associated HNSCC. [ABSTRACT FROM AUTHOR]
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- 2022
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4. MicroRNA-182-5p and microRNA-205-5p as potential biomarkers for prognostic stratification of p16-positive oropharyngeal squamous cell carcinoma.
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Weiss, Bernhard G., Anczykowski, Mahalia Zoe, Ihler, Friedrich, Bertlich, Mattis, Spiegel, Jennifer L., Haubner, Frank, Canis, Martin, Küffer, Stefan, Hess, Julia, Unger, Kristian, Kitz, Julia, and Jakob, Mark
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SQUAMOUS cell carcinoma ,MICRORNA ,PROGNOSIS ,PROGRESSION-free survival - Abstract
BACKGROUND: MicroRNAs constitute promising biomarkers. OBJECTIVE: The aim was to investigate diagnostic and prognostic implications of miR-182-5p and miR-205-5p in p16-positive and p16-negative oropharyngeal squamous cell carcinomas (OPSCCs). METHODS: Expression of miR-182-5p, miR-205-5p were determined via quantitative real-time-PCR in fresh frozen tissues of 26 p16-positive, 19 p16-negative OPSCCs and 18 HPV-negative oropharyngeal controls. Associations between miRNA-expression, clinicopathological characteristics and prognosis were analyzed. RESULTS: Higher miR-182-5p expression was associated with significant inferior disease-specific survival for p16-positive OPSCCs (HR = 1.98E + 09, 95% CI 0–Inf; P = 0.028) and a similar trend was observed for p16-negative OPSCCs (HR = 1.56E + 09, 95% CI 0–Inf; P = 0.051). Higher miR-205-5p expression was associated with an inferior progression-free survival (HR = 4.62, 95% CI 0.98–21.83; P = 0.034) and local control rate (HR = 2.18E + 09, 95% CI 0–Inf; P = 0.048) for p16-positive OPSCCs. CONCLUSIONS: Results indicate that miR-182-5p and miR-205-5p can further stratify patients with p16-positive OPSCC into prognostic groups. [ABSTRACT FROM AUTHOR]
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- 2022
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5. Human microRNA‐182‐5p and kinectin 1: Potential biomarkers for prognosis in oral squamous cell carcinoma.
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Jakob, Mark, Mattes, Lena M., Unger, Kristian, Kueffer, Stefan, Hess, Julia, Canis, Martin, Schirmer, Markus, Spiegel, Jennifer L., Haubner, Frank, Ihler, Friedrich, Weiss, Bernhard G., and Kitz, Julia
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SQUAMOUS cell carcinoma ,PROGNOSIS ,MICRORNA ,MUCOUS membranes ,PROGRESSION-free survival - Abstract
Background: The prognostic impact of hsa‐miRNA‐182‐5p in oral cancer remains unexplored. Therefore, the aim of this study was to investigate the prognostic value of hsa‐miRNA‐182‐5p and its predicted target kinectin 1 (KTN1) in oral squamous cell carcinoma (OSCC). Method: Expression level of hsa‐miRNA‐182‐5p was analyzed in tumor tissue (n = 36) and healthy oral mucosal tissue (n = 17) using quantitative real‐time polymerase chain reaction. Protein level of the predicted target KTN1 was detected via immunohistochemistry. Results were validated in a cohort of The Cancer Genome Atlas (TCGA). Results: After dividing the data into a subgroup with high and low hsa‐miRNA‐182‐5p expression level, a significant better overall (p = 0.016), recurrence‐free (p = 0.009), and progression‐free survival (p = 0.004) was observed in an upregulation of hsa‐miRNA‐182‐5p. Staining intensity of KTN1 showed a reciprocal impact on the prognosis. Validation in a TCGA cohort confirmed these results. Conclusion: Our results indicate hsa‐miRNA‐182‐5p and KTN1 as potential biomarkers for OSCC. [ABSTRACT FROM AUTHOR]
- Published
- 2021
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6. MicroRNA expression patterns in oral squamous cell carcinoma: hsa‐mir‐99b‐3p and hsa‐mir‐100‐5p as novel prognostic markers for oral cancer.
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Jakob, Mark, Mattes, Lena M., Küffer, Stefan, Unger, Kristian, Hess, Julia, Bertlich, Mattis, Haubner, Frank, Ihler, Friedrich, Canis, Martin, Weiss, Bernhard G., and Kitz, Julia
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SQUAMOUS cell carcinoma ,TUMOR markers ,ORAL cancer ,MICRORNA ,MUCOUS membranes - Abstract
Background: MicroRNAs (miRNA) recently evolved as potential cancer biomarkers. Therefore, the aim of the present study was to evaluate the prognostic impact of eight miRNAs connected to oral squamous cell carcinoma (OSCC). Method: Expression levels of hsa‐mir‐21‐5p, hsa‐mir‐29b‐3p, hsa‐mir‐31‐5p, hsa‐mir‐99a‐5p, hsa‐mir‐99b‐3p, hsa‐mir‐100‐5p, hsa‐mir‐143‐3p and hsa‐mir‐155‐5p were analyzed in tumor tissue (n = 36) and healthy oral mucosal tissue (n = 17) and correlated with clinical variables. Results of the study cohort were validated in an OSCC cohort of The Cancer Genome Atlas. Results: Increased hsa‐mir‐99b‐3p expression level showed a tendency toward advanced tumor stages, and high levels of hsa‐mir‐100‐5p expression were associated with extracapsular extension. While a high expression level of hsa‐mir‐99b‐3p was associated with better survival, a high expression level of hsa‐mir‐100‐5p was correlated with a poorer survival in the study cohort. Conclusion: Our results indicate that hsa‐mir‐99b‐3p and hsa‐mir‐100‐5p may serve as novel prognostic biomarkers in OSCC. [ABSTRACT FROM AUTHOR]
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- 2019
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7. MicroRNA-Target Network Inference and Local Network Enrichment Analysis Identify Two microRNA Clusters with Distinct Functions in Head and Neck Squamous Cell Carcinoma.
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Sass, Steffen, Pitea, Adriana, Unger, Kristian, Hess, Julia, Mueller, Nikola S., and Theis, Fabian J.
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MICRORNA ,SQUAMOUS cell carcinoma ,HEAD & neck cancer ,GENE expression ,PAPILLOMAVIRUSES ,GENETICS - Abstract
MicroRNAs represent ~22 nt long endogenous small RNA molecules that have been experimentally shown to regulate gene expression post-transcriptionally. One main interest in miRNA research is the investigation of their functional roles, which can typically be accomplished by identification of mi-/mRNA interactions and functional annotation of target gene sets. We here present a novel method "miRlastic", which infers miRNA-target interactions using transcriptomic data as well as prior knowledge and performs functional annotation of target genes by exploiting the local structure of the inferred network. For the network inference, we applied linear regression modeling with elastic net regularization on matched microRNA and messenger RNA expression profiling data to perform feature selection on prior knowledge from sequence-based target prediction resources. The novelty of miRlastic inference originates in predicting data-driven intra-transcriptome regulatory relationships through feature selection. With synthetic data, we showed that miRlastic outperformed commonly used methods and was suitable even for low sample sizes. To gain insight into the functional role of miRNAs and to determine joint functional properties of miRNA clusters, we introduced a local enrichment analysis procedure. The principle of this procedure lies in identifying regions of high functional similarity by evaluating the shortest paths between genes in the network. We can finally assign functional roles to the miRNAs by taking their regulatory relationships into account. We thoroughly evaluated miRlastic on a cohort of head and neck cancer (HNSCC) patients provided by The Cancer Genome Atlas. We inferred an mi-/mRNA regulatory network for human papilloma virus (HPV)-associated miRNAs in HNSCC. The resulting network best enriched for experimentally validated miRNA-target interaction, when compared to common methods. Finally, the local enrichment step identified two functional clusters of miRNAs that were predicted to mediate HPV-associated dysregulation in HNSCC. Our novel approach was able to characterize distinct pathway regulations from matched miRNA and mRNA data. An R package of miRlastic was made available through: http://icb.helmholtz-muenchen.de/mirlastic. [ABSTRACT FROM AUTHOR]
- Published
- 2015
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8. Integrative analysis of the microRNA-mRNA response to radiochemotherapy in primary head and neck squamous cell carcinoma cells.
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Summerer, Isolde, Hess, Julia, Pitea, Adriana, Unger, Kristian, Hieber, Ludwig, Selmansberger, Martin, Lauber, Kirsten, and Zitzelsberger, Horst
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HEAD & neck cancer treatment ,SQUAMOUS cell carcinoma ,MICRORNA ,CANCER chemotherapy ,CANCER radiotherapy ,CANCER cells - Abstract
Background: Head and neck squamous cell carcinoma (HNSCC) is a very heterogeneous disease resulting in huge differences in the treatment response. New individualized therapy strategies including molecular targeting might help to improve treatment success. In order to identify potential targets, we developed a HNSCC radiochemotherapy cell culture model of primary HNSCC cells derived from two different patients (HN1957 and HN2092) and applied an integrative microRNA (miRNA) and mRNA analysis in order to gain information on the biological networks and processes of the cellular therapy response. We further identified potential target genes of four therapy-responsive miRNAs detected previously in the circulation of HNSCC patients by pathway enrichment analysis. Results: The two primary cell cultures differ in global copy number alterations and P53 mutational status, thus reflecting heterogeneity of HNSCC. However, they also share many copy number alterations and chromosomal rearrangements as well as deregulated therapy-responsive miRNAs and mRNAs. Accordingly, six common therapy-responsive pathways (direct P53 effectors, apoptotic execution phase, DNA damage/telomere stress induced senescence, cholesterol biosynthesis, unfolded protein response, dissolution of fibrin clot) were identified in both cell cultures based on deregulated mRNAs. However, inflammatory pathways represented an important part of the treatment response only in HN1957, pointing to differences in the treatment responses of the two primary cultures. Focused analysis of target genes of four therapy-responsive circulating miRNAs, identified in a previous study on HNSCC patients, revealed a major impact on the pathways direct P53 effectors, the E2F transcription factor network and pathways in cancer (mainly represented by the PTEN/AKT signaling pathway). Conclusions: The integrative analysis combining miRNA expression, mRNA expression and the related cellular pathways revealed that the majority of radiochemotherapy-responsive pathways in primary HNSCC cells are related to cell cycle, proliferation, cell death and stress response (including inflammation). Despite the heterogeneity of HNSCC, the two primary cell cultures exhibited strong similarities in the treatment response. The findings of our study suggest potential therapeutic targets in the E2F transcription factor network and the PTEN/AKT signaling pathway. [ABSTRACT FROM AUTHOR]
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- 2015
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9. Changes in circulating microRNAs after radiochemotherapy in head and neck cancer patients.
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Summerer, Isolde, Niyazi, Maximilian, Unger, Kristian, Pitea, Adriana, Zangen, Verena, Hess, Julia, Atkinson, Michael J., Belka, Claus, Moertl, Simone, and Zitzelsberger, Horst
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HEAD & neck cancer treatment ,MICRORNA ,CANCER radiotherapy ,SQUAMOUS cell carcinoma ,CANCER chemotherapy ,ANTINEOPLASTIC agents ,BLOOD plasma ,TUMOR markers ,RNA metabolism ,THERAPEUTIC use of antineoplastic agents ,HEAD tumors ,RESEARCH ,RESEARCH methodology ,RNA ,CELL physiology ,MICROARRAY technology ,PROGNOSIS ,MEDICAL cooperation ,EVALUATION research ,TREATMENT effectiveness ,COMPARATIVE studies ,GENES ,GENE expression profiling ,STEM cells ,CELL lines ,CLUSTER analysis (Statistics) ,POLYMERASE chain reaction ,NECK tumors - Abstract
Introduction: Circulating microRNAs (miRNAs) are easily accessible and have already proven to be useful as prognostic markers in cancer patients. However, their origin and function in the circulation is still under discussion. In the present study we analyzed changes in the miRNAs in blood plasma of head and neck squamous cell carcinoma (HNSCC) patients in response to radiochemotherapy and compared them to the changes in a cell culture model of primary HNSCC cells undergoing simulated anti-cancer therapy.Materials and Methods: MiRNA-profiles were analyzed by qRT-PCR arrays in paired blood plasma samples of HNSCC patients before therapy and after two days of treatment. Candidate miRNAs were validated by single qRT-PCR assays. An in vitro radiochemotherapy model using primary HNSCC cell cultures was established to test the possible tumor origin of the circulating miRNAs. Microarray analysis was performed on primary HNSCC cell cultures followed by validation of deregulated miRNAs via qRT-PCR.Results: Unsupervised clustering of the expression profiles using the six most regulated miRNAs (miR-425-5p, miR-21-5p, miR-106b-5p, miR-590-5p, miR-574-3p, miR-885-3p) significantly (p = 0.012) separated plasma samples collected prior to treatment from plasma samples collected after two days of radiochemotherapy. MiRNA profiling of primary HNSCC cell cultures treated in vitro with radiochemotherapy revealed differentially expressed miRNAs that were also observed to be therapy-responsive in blood plasma of the patients (miR-425-5p, miR-21-5p, miR-106b-5p, miR-93-5p) and are therefore likely to stem from the tumor. Of these candidate marker miRNAs we were able to validate by qRT-PCR a deregulation of eight plasma miRNAs as well as miR-425-5p and miR-93-5p in primary HNSCC cultures after radiochemotherapy.Conclusion: Changes in the abundance of circulating miRNAs during radiochemotherapy reflect the therapy response of primary HNSCC cells after an in vitro treatment. Therefore, the responsive miRNAs (miR-425-5p, miR-93-5p) may represent novel biomarkers for therapy monitoring. The prognostic value of this exciting observation requires confirmation using an independent patient cohort that includes clinical follow-up data. [ABSTRACT FROM AUTHOR]- Published
- 2013
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10. MicroRNA profiling with correlation to gene expression revealed the oncogenic miR-17-92 cluster to be up-regulated in osteosarcoma
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Baumhoer, Daniel, Zillmer, Stephanie, Unger, Kristian, Rosemann, Michael, Atkinson, Michael J., Irmler, Martin, Beckers, Johannes, Siggelkow, Heide, von Luettichau, Irene, Jundt, Gernot, Smida, Jan, and Nathrath, Michaela
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MICRORNA , *GENE expression , *TUMOR suppressor genes , *ONCOGENES , *OSTEOSARCOMA , *CELL lines , *CELL differentiation - Abstract
Osteosarcomas are genetically complex tumors with abundant structural and numerical alterations. The molecular pathogenesis of the disease is, however, still poorly understood. Aside from various oncogenes and tumor suppressor genes, deregulated microRNAs (miRNAs) are known to influence tumor development and biology. We therefore investigated six well-established osteosarcoma cell lines (HOS58, U2-OS, Saos-2, MNNG/HOS, SJSA-1, and MG-63) for genome-wide miRNA expression (miRBase Version 15.0, http://www.mirbase.org/) and correlated our findings with gene expression. Cultured osteoblasts (hFOB 1.19) and mesenchymal stem cells (L87/4) were used as normal references. Focusing only on miRNAs that were deregulated in the majority of osteosarcoma cell lines, we identified several miRNAs with oncogenic and tumor suppressor properties, including various members of the oncogenic miR-17-92 cluster. In addition, several genes involved in differentiation (RGMB, LRRC17), cell cycle control (CCNE1), and apoptosis (LIMA1, CAMK2N1) were found to be deregulated in osteosarcoma cell lines, most likely due to altered miRNA expression patterns. Our findings indicate a crucial impact of deregulated miRNAs with consecutive changes in gene expression in osteosarcomas, which strongly suggests pathogenetic and potentially therapeutic implications. [ABSTRACT FROM AUTHOR]
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- 2012
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