Felix K.H. Chun

Dr. Felix K.H. Chun

Department of Urology, University Hospital Frankfurt, Goethe University Frankfurt am Main, Frankfurt am Main, Germany Theodor-Stern-Kai 7, 60590 Frankfurt am Main, Germany

Research Focus & Metrics

Academic Career Length

9Years (2018-Present)

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

Representative Publications

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Verified
Journal Article
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JRJochen Rutz
Jochen Rutz
STSarah Thaler
Sarah Thaler
SMSebastian Maxeiner
Sebastian Maxeiner
FCFelix K.H. Chun
Felix K.H. Chun
RBRoman A. Blaheta
Roman A. Blaheta
Prostate cancer patients whose tumors develop resistance to conventional treatment often turn to natural, plant-derived products, one of which is sulforaphane (SFN). This study was designed to determine whether anti-tumor properties of SFN, identified in other tumor entities, are also evident in cultivated DU145 and PC3 prostate cancer cells. The cells were incubated with SFN (1–20 µM) and tumor cell growth and proliferative activity were evaluated. Having found a considerable anti-growth, anti-proliferative, and anti-clonogenic influence of SFN on both prostate cancer cell lines, further investigation into possible mechanisms of action were performed by evaluating the cell cycle phases and cell-cycle-regulating proteins. SFN induced a cell cycle arrest at the S- and G2/M-phase in both DU145 and PC3 cells. Elevation of histone H3 and H4 acetylation was also evident in both cell lines following SFN exposure. However, alterations occurring in the Cdk-cyclin axis, modification of the p19 and p27 proteins and changes in CD44v4, v5, and v7 expression because of SFN exposure differed in the two cell lines. SFN, therefore, does exert anti-tumor properties on these two prostate cancer cell lines by histone acetylation and altering the intracellular signaling cascade, but not through the same molecular mechanisms.

1 May 2021 in Journal of Endourology
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Journal Article
Closed access
PGPhilipp Gild
Philipp Gild
LLLukas Lenke
Lukas Lenke
RPRaisa Sinaida Pompe
Raisa Sinaida Pompe
MVMalte Wolfram Vetterlein
Malte Wolfram Vetterlein
TLTim Alexander Ludwig
Tim Alexander Ludwig
ABAndreas Becker
Andreas Becker
Purpose: To assess perioperative outcomes of HoLEP in a real-world scenario and with a focus on demanding patient factors such as large prostate size, advanced patient age, and anticoagulation therapy (AT). Material & Methods: We retrospectively analysed HoLEP procedures at our institution between 2010-2016. After stratification by prostate volume, age, and AT, perioperative and early voiding characteristics were compared. A multivariable regression model was employed to identify predictors of prolonged time of catheterization (defined as being above groups median). Results: The study cohort consisted of 1,816 men with a median age of 71 years (IQR:66-76), a median prostate volume of 80 ml (IQR:58-105) and American Society of Anesthesiologists (ASA) score ≥3 in 618 men (34%). Median time of enucleation and morcellation were 43 min (IQR:31-60) and 10 min (IQR:6-18), respectively. Perioperative blood transfusions were administered in 44 (2.4%) cases, severe postoperative complications (Clavien-Dindo grade ≥3b) occured in 61 (3.3%) of cases. The median time of catheterization was 2 days (IQR: 2-2), with prolonged catheterization occuring in 277 (15%) of cases. After adjustment, very large prostates (4th volume quartile (106-280ml) (OR:1.8, 95%CI:1.3-2.6, p=0.001), therapeutic low-molecular-weight heparin bridging regimen (OR: 2.2, 95%CI:1.4-3.6, p=0.037), low-dose acetylsalicyclic acid (OR:1.5, 95%CI:1.0-2.2, p=0.015), and a history of direct oral anticoagulation (OR:2.3, 95%CI:1.2-4.0, p=0.022), but not patient age, were independently associated with prolonged catherization. Conclusions: We confirm HoLEP as safe and efficient; however, patients with very large prostates and patients with a history of anticoagulation therapy are at risk of prolonged catheterization.

Verified
Journal Article
Open access
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Hui XieHui Xie
Hui Xie
FCFelix K.H. Chun
Felix K.H. Chun
JRJochen Rutz
Jochen Rutz
RBRoman A. Blaheta
Roman A. Blaheta
Sulforaphane (SFN) is a natural glucosinolate found in cruciferous vegetables that acts as a chemopreventive agent, but its mechanism of action is not clear. Due to antioxidative mechanisms being thought central in preventing cancer progression, SFN could play a role in oxidative processes. Since redox imbalance with increased levels of reactive oxygen species (ROS) is involved in the initiation and progression of bladder cancer, this mechanism might be involved when chemoresistance occurs. This review summarizes current understanding regarding the influence of SFN on ROS and ROS-related pathways and appraises a possible role of SFN in bladder cancer treatment.

Verified
Journal Article
Open access
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SJSaira Justin
Saira Justin
JRJochen Rutz
Jochen Rutz
SMSebastian Maxeiner
Sebastian Maxeiner
FCFelix K.H. Chun
Felix K.H. Chun
EJEva Juengel
Eva Juengel
RBRoman A. Blaheta
Roman A. Blaheta
Progressive bladder cancer growth is associated with abnormal activation of the mammalian target of the rapamycin (mTOR) pathway, but treatment with an mTOR inhibitor has not been as effective as expected. Rather, resistance develops under chronic drug use, prompting many patients to lower their relapse risk by turning to natural, plant-derived products. The present study was designed to evaluate whether the natural compound, sulforaphane (SFN), combined with the mTOR inhibitor everolimus, could block the growth and proliferation of bladder cancer cells in the short- and long-term. The bladder cancer cell lines RT112, UMUC3, and TCCSUP were exposed short- (24 h) or long-term (8 weeks) to everolimus (0.5 nM) or SFN (2.5 µM) alone or in combination. Cell growth, proliferation, apoptosis, cell cycle progression, and cell cycle regulating proteins were evaluated. siRNA blockade was used to investigate the functional impact of the proteins. Short-term application of SFN and/or everolimus resulted in significant tumor growth suppression, with additive inhibition on clonogenic tumor growth. Long-term everolimus treatment resulted in resistance development characterized by continued growth, and was associated with elevated Akt-mTOR signaling and cyclin-dependent kinase (CDK)1 phosphorylation and down-regulation of p19 and p27. In contrast, SFN alone or SFN+everolimus reduced cell growth and proliferation. Akt and Rictor signaling remained low, and p19 and p27 expressions were high under combined drug treatment. Long-term exposure to SFN+everolimus also induced acetylation of the H3 and H4 histones. Phosphorylation of CDK1 was diminished, whereby down-regulation of CDK1 and its binding partner, Cyclin B, inhibited tumor growth. In conclusion, the addition of SFN to the long-term everolimus application inhibits resistance development in bladder cancer cells in vitro. Therefore, sulforaphane may hold potential for treating bladder carcinoma in patients with resistance to an mTOR inhibitor.

26 September 2022 in Cancers
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Journal Article
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Hui XieHui Xie
Hui Xie
JRJochen Rutz
Jochen Rutz
SMSebastian Maxeiner
Sebastian Maxeiner
TGTimothy Grein
Timothy Grein
ATAnita Thomas
Anita Thomas
RBRoman A. Blaheta
Roman A. Blaheta
Combined cisplatin–gemcitabine (GC) application is standard for treating muscle-invasive bladder cancer. However, since rapid resistance to treatment often develops, many patients turn to supplements in the form of plant-based compounds. Sulforaphane (SFN), derived from cruciferous vegetables, is one such compound, and the present study was designed to investigate its influence on growth and proliferation in a panel of drug-sensitive bladder cancer cell lines, as well as their gemcitabine- and cisplatin-resistant counterparts. Chemo-sensitive and -resistant RT4, RT112, T24, and TCCSUP cell lines were exposed to SFN in different concentrations, and tumor growth, proliferation, and clone formation were evaluated, in addition to apoptosis and cell cycle progression. Means of action were investigated by assaying cell-cycle-regulating proteins and the mechanistic target of rapamycin (mTOR)/AKT signaling cascade. SFN significantly inhibited growth, proliferation, and clone formation in all four tumor cell lines. Cells were arrested in the G2/M and/or S phase, and alteration of the CDK–cyclin axis was closely associated with cell growth inhibition. The AKT/mTOR signaling pathway was deactivated in three of the cell lines. Acetylation of histone H3 was up-regulated. SFN, therefore, does exert tumor-suppressive properties in cisplatin- and gemcitabine-resistant bladder cancer cells and could be beneficial in optimizing bladder cancer therapy.

12 January 2022 in Cancers
Verified
Journal Article
Open access
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CSCarolin Siech
Carolin Siech
JRJochen Rutz
Jochen Rutz
SMSebastian Maxeiner
Sebastian Maxeiner
TGTimothy Grein
Timothy Grein
MSMarlon Sonnenburg
Marlon Sonnenburg
RBRoman A. Blaheta
Roman A. Blaheta
Insulin-like growth factor-1 (IGF-1)-related signaling is associated with prostate cancer progression. Links were explored between IGF-1 and expression of integrin adhesion receptors to evaluate relevance for growth and migration. Androgen-resistant PC3 and DU145 and androgen-sensitive LNCaP and VCaP prostate cancer cells were stimulated with IGF-1 and tumor growth (all cell lines), adhesion and chemotaxis (PC3, DU145) were determined. Evaluation of Akt/mTOR-related proteins, focal adhesion kinase (FAK) and integrin α and β subtype expression followed. Akt knock-down was used to investigate its influence on integrin expression, while FAK blockade served to evaluate its influence on mTOR signaling. Integrin knock-down served to investigate its influence on tumor growth and chemotaxis. Stimulation with IGF-1 activated growth in PC3, DU145, and VCaP cells, and altered adhesion and chemotactic properties of DU145 and PC3 cells. This was associated with time-dependent alterations of the integrins α3, α5, αV, and β1, FAK phosphorylation and Akt/mTOR signaling. Integrin blockade or integrin knock-down in DU145 and PC3 cells altered tumor growth, adhesion, and chemotaxis. Akt knock-down (DU145 cells) cancelled the effect of IGF-1 on α3, α5, and αV integrins, whereas FAK blockade cancelled the effect of IGF-1 on mTOR signaling (DU145 cells). Prostate cancer growth and invasion are thus controlled by a fine-tuned network between IGF-1 driven integrin-FAK signaling and the Akt-mTOR pathway. Concerted targeting of integrin subtypes along with Akt-mTOR signaling could, therefore, open options to prevent progressive dissemination of prostate cancer.