Markus Krebs

Markus Krebs

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Research Focus & Metrics

Academic Career Length

15Years (2012-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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MKMarkus Krebs
Markus Krebs
Antonio Giovanni SolimandoAntonio Giovanni Solimando
Antonio Giovanni Solimando
CKCharis Kalogirou
Charis Kalogirou
AMAndré Marquardt
André Marquardt
TFTorsten Frank
Torsten Frank
BKBurkhard Kneitz
Burkhard Kneitz
Downregulation of miR-221-3p expression in prostate cancer (PCa) predicted overall and cancer-specific survival of high-risk PCa patients. Apart from PCa, miR-221-3p expression levels predicted a response to tyrosine kinase inhibitors (TKI) in clear cell renal cell carcinoma (ccRCC) patients. Since this role of miR-221-3p was explained with a specific targeting of VEGFR2, we examined whether miR-221-3p regulated VEGFR2 in PCa. First, we confirmed VEGFR2/KDR as a target gene of miR-221-3p in PCa cells by applying Luciferase reporter assays and Western blotting experiments. Although VEGFR2 was mainly downregulated in the PCa cohort of the TCGA (The Cancer Genome Atlas) database, VEGFR2 was upregulated in our high-risk PCa cohort (n = 142) and predicted clinical progression. In vitro miR-221-3p acted as an escape mechanism from TKI in PC3 cells, as displayed by proliferation and apoptosis assays. Moreover, we confirmed that Sunitinib induced an interferon-related gene signature in PC3 cells by analyzing external microarray data and by demonstrating a significant upregulation of miR-221-3p/miR-222-3p after Sunitinib exposure. Our findings bear a clinical perspective for high-risk PCa patients with low miR-221-3p levels since this could predict a favorable TKI response. Apart from this therapeutic niche, we identified a partially oncogenic function of miR-221-3p as an escape mechanism from VEGFR2 inhibition.

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AAAntonella Argentiero
Antonella Argentiero
Antonio Giovanni SolimandoAntonio Giovanni Solimando
Antonio Giovanni Solimando
MKMarkus Krebs
Markus Krebs
Patrizia LeonePatrizia Leone
Patrizia Leone
NSNicola Susca
Nicola Susca
Nicola SilvestrisNicola Silvestris
Nicola Silvestris
Although decision making strategy based on clinico-histopathological criteria is well established, renal cell carcinoma (RCC) represents a spectrum of biological ecosystems characterized by distinct genetic and molecular alterations, diverse clinical courses and potential specific therapeutic vulnerabilities. Given the plethora of drugs available, the subtype-tailored treatment to RCC subtype holds the potential to improve patient outcome, shrinking treatment-related morbidity and cost. The emerging knowledge of the molecular taxonomy of RCC is evolving, whilst the antiangiogenic and immunotherapy landscape maintains and reinforces their potential. Although several prognostic factors of survival in patients with RCC have been described, no reliable predictive biomarkers of treatment individual sensitivity or resistance have been identified. In this review, we summarize the available evidence able to prompt more precise and individualized patient selection in well-designed clinical trials, covering the unmet need of medical choices in the era of next-generation anti-angiogenesis and immunotherapy.

25 June 2019 in BMC Cancer
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MKMirjam Kiener
Mirjam Kiener
LCLanpeng Chen
Lanpeng Chen
MKMarkus Krebs
Markus Krebs
JGJoël Grosjean
Joël Grosjean
IKIrena Klima
Irena Klima
EZEugenio Zoni
Eugenio Zoni
Despite latest advances in prostate cancer (PCa) therapy, PCa remains the third-leading cause of cancer-related death in European men. Dysregulation of microRNAs (miRNAs), small non-coding RNA molecules with gene expression regulatory function, has been reported in all types of epithelial and haematological cancers. In particular, miR-221-5p alterations have been reported in PCa. miRNA expression data was retrieved from a comprehensive publicly available dataset of 218 PCa patients (GSE21036) and miR-221-5p expression levels were analysed. The functional role of miR-221-5p was characterised in androgen- dependent and androgen- independent PCa cell line models (C4–2 and PC-3M-Pro4 cells) by miR-221-5p overexpression and knock-down experiments. The metastatic potential of highly aggressive PC-3M-Pro4 cells overexpressing miR-221-5p was determined by studying extravasation in a zebrafish model. Finally, the effect of miR-221-5p overexpression on the growth of PC-3M-Pro4luc2 cells in vivo was studied by orthotopic implantation in male Balb/cByJ nude mice and assessment of tumor growth. Analysis of microRNA expression dataset for human primary and metastatic PCa samples and control normal adjacent benign prostate revealed miR-221-5p to be significantly downregulated in PCa compared to normal prostate tissue and in metastasis compared to primary PCa. Our in vitro data suggest that miR-221-5p overexpression reduced PCa cell proliferation and colony formation. Furthermore, miR-221-5p overexpression dramatically reduced migration of PCa cells, which was associated with differential expression of selected EMT markers. The functional changes of miR-221-5p overexpression were reversible by the loss of miR-221-5p levels, indicating that the tumor suppressive effects were specific to miR-221-5p. Additionally, miR-221-5p overexpression significantly reduced PC-3M-Pro4 cell extravasation and metastasis formation in a zebrafish model and decreased tumor burden in an orthotopic mouse model of PCa. Together these data strongly support a tumor suppressive role of miR-221-5p in the context of PCa and its potential as therapeutic target.

4 November 2021 in Blood
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LHLarissa Haertle
Larissa Haertle
SBSantiago Barrio
Santiago Barrio
UMUmair Munawar
Umair Munawar
SHSeungbin Han
Seungbin Han
XZXiang Zhou
Xiang Zhou
KKK. Martin Kortüm
K. Martin Kortüm
Cereblon is the direct binding target of the immunomodulatory drugs (IMiDs) that are commonly used to treat multiple myeloma (MM), the second most frequent hematologic malignancy. Patients respond well to initial treatment with IMiDs, but virtually all patients develop drug resistance over time, and the underlying mechanisms are poorly understood. We identified an as yet undescribed DNA hypermethylation in an active intronic CRBN enhancer. Differential hypermethylation in this region was found to be increased in healthy plasma cells, but was more pronounced in IMiD-refractory MM. Methylation significantly correlated with decreased CRBN expression levels. DNA methyltransferase inhibitor (DNTMi) in vitro experiments induced CRBN enhancer demethylation, and sensitizing effects on lenalidomide treatment were observed in 2 MM cell lines. Thus, we provide first evidence that aberrant CRBN DNA methylation is a novel mechanism of IMiD resistance in MM and may predict IMiD response prior to treatment.

1 September 2019 in Journal of Urology
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ISIoannis Sokolakis
Ioannis Sokolakis
TSTina Schubert
Tina Schubert
MOMarkus Oelschlaeger
Markus Oelschlaeger
MKMarkus Krebs
Markus Krebs
JGJürgen E. Gschwend
Jürgen E. Gschwend
GHGeorgios Hatzichristodoulou
Georgios Hatzichristodoulou
Purpose:To evaluate the role of magnetic resonance imaging (MRI) of the penis in the diagnosis of penile fracture and/or concomitant urethral lesion in real-life emergency settings in comparison with intraoperative findings.Materials and methods:Forty-three patients presented with suspicion of penile fracture between January 2006 and December 2016. MRI was performed in 28 patients prior to surgical treatment in emergency settings. Surgery was performed in all patients through subcoronal circumferential degloving approach. Sensitivity, specificity, positive and negative predictive value (PPV/NPV), as well as the likelihood ratio for positive and negative results (LR+/LR-) were calculated for the agreement between MRI and intraoperative findings. Confidence intervals (CI) were set at 95%.Results:Intraoperatively, penile fracture was confirmed in 19/28 (67.9%) patients, while concomitant urethral lesion was observed in 5/28 patients (17.9%). MRI findings were highly associated with intraoperative fin...

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VBVerena Boschert
Verena Boschert
JTJonas Teusch
Jonas Teusch
AAAnwar Aljasem
Anwar Aljasem
PSPhilipp Schmucker
Philipp Schmucker
NKNicola Klenk
Nicola Klenk
Stefan HartmannStefan Hartmann
Stefan Hartmann
Head and neck squamous cell carcinoma (HNSCC) is a widespread disease with a low survival rate and a high risk of recurrence. Nowadays, immune checkpoint inhibitor (ICI) treatment is approved for HNSCC as a first-line treatment in recurrent and metastatic disease. ICI treatment yields a clear survival benefit, but overall response rates are still unsatisfactory. As shown in different cancer models, hepatocyte growth factor/mesenchymal–epithelial transition (HGF/Met) signaling contributes to an immunosuppressive microenvironment. Therefore, we investigated the relationship between HGF and programmed cell death protein 1 (PD-L1) expression in HNSCC cell lines. The preclinical data show a robust PD-L1 induction upon HGF stimulation. Further analysis revealed that the HGF-mediated upregulation of PD-L1 is MAP kinase-dependent. We then hypothesized that serum levels of HGF and soluble programmed cell death protein 1 (sPD-L1) could be potential markers of ICI treatment failure. Thus, we determined serum levels of these proteins in 20 HNSCC patients before ICI treatment and correlated them with treatment outcomes. Importantly, the clinical data showed a positive correlation of both serum proteins (HGF and sPD-L1) in HNSCC patient’s sera. Moreover, the serum concentration of sPD-L1 was significantly higher in ICI non-responsive patients. Our findings indicate a potential role for sPD-L1 as a prognostic marker for ICI treatment in HNSCC.