Michael Chaloupka

Dr. Michael Chaloupka


Research Focus & Metrics

Academic Career Length

10Years (2017-Present)

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

Representative Publications

View All Publications
30 August 2018 in Frontiers in Immunology
Verified
Journal Article
Open access
PDF file
FRFelicitas Rataj
Felicitas Rataj
FKFabian B. T. Kraus
Fabian B. T. Kraus
MCMichael Chaloupka
Michael Chaloupka
SGSimon Grassmann
Simon Grassmann
CHConstanze Heise
Constanze Heise
SKSebastian Kobold
Sebastian Kobold
Background: Interaction of the programmed death receptor 1 (PD-1) and its ligand, PD-L1, suppresses T cell activity and permits tumors to evade T cell-mediated immune surveillance. We have recently demonstrated that antigen-specific CD8+ T cells transduced with a PD1-CD28 fusion protein are protected from PD-1-mediated inhibition. We have now investigated the potential of PD1-CD28 fusion protein-transduced CD4+ T cells alone or in combination with CD8+ T cells for immunotherapy of pancreatic cancer and non-Hodgkin lymphoma. Methods: OVA-specific CD4+ and CD8+ were retrovirally transduced with the PD1-CD28 fusion protein. Cytokine release, proliferation, cytotoxic activity, and phenotype of transduced T cells were assessed in the context of Panc02-OVA (murine pancreatic cancer model) and E.G7-PD-L1 (murine T cell lymphoma model) cells. Results: Stimulation of PD1-CD28 fusion protein-transduced CD4+ T cells with anti-CD3 and recombinant PD-L1 induced specific T cell activation, as measured by IFN-y release and T cell proliferation. Coculture with Panc02-OVA or E.G7-PD-L1 tumor cells also led to specific activation of CD4+ T cells. Cytokine release and T cell proliferation was most effective when tumor cells simultaneously encountered genetically engineered CD4+ and CD8+ T cells. Synergy between both cell populations was also observed for specific tumor cell lysis. T cell cytotoxicity was mediated via granzyme B release and mediated enhanced tumor control in vivo. Transduced CD4+ and CD8+ T cells in co-culture with tumor cells developed a predominant central memory phenotype over time. Different ratios of CD4+ and CD8+ transduced T cells led to a significant increase of IFN-y and IL-2 secretion positively correlating with CD4+ T cell numbers used. Mechanistically, IL-2 and MHC-I were central to the synergistic activity of CD4+ and CD8+ T cells, since neutralization of IL-2 prevented the crosstalk between these cell populations. Conclusion: PD1-CD28 fusion protein-transduced CD4+ T cells significantly improved anti-tumoral effect of fusion protein-transduced CD8+ T cells. Thus, our results indicate that PD1-CD28 fusion protein-transduced CD4+ T cells have the potential to overcome the PD-1-PD-L1 immunosuppressive axis in pancreatic cancer and non-Hodgkin lymphoma.

16 February 2023 in Cancers
Verified
Journal Article
Open access
PDF file
MCMichael Chaloupka
Michael Chaloupka
MAMaria Apfelbeck
Maria Apfelbeck
NPNikolaos Pyrgidis
Nikolaos Pyrgidis
JMJulian Marcon
Julian Marcon
PWPhilipp Dr. Weinhold
Philipp Dr. Weinhold
CSChristian G. Stief
Christian G. Stief
Modern risk stratification of prostate cancer (PCa) allows for prediction of advanced disease with a high level of certainty. We aimed to evaluate a prospective series of patients undergoing radical prostatectomy without prior biopsy based solely on clinical criteria and imaging results. The patients were divided into three groups. Group 1 included 27 patients with: (i) suspicious digital rectal examination, (ii) PSA ≥ 10 ng/mL, (iii) PI-RADS 4/5 on mpMRI, and (iv) high suspicion of PCa on PSMA-PET. Group 2 included six patients who fulfilled criteria i, ii, and iii but did not undergo PSMA-PET imaging. Group 3 included 17 patients with at least one clinical (i or ii) and one imaging (iii or iv) criterion. All of the patients were diagnosed with PCa. Comparison of Group 1 and 2 versus Group 3 showed a significantly higher ratio of locally advanced PCa for Groups 1 and 2 compared to Group 3 (60.6% versus 11.8%, p = 0.005, respectively). Similarly, these patients displayed a significantly higher ratio of aggressive PCa (ISUP grade > 2: 66.7% versus 23.5%, p = 0.027, respectively) and tumor infiltration (median tumor infiltration: 32.5% vs. 15%, p = 0.001, respectively) in the final specimen compared to Group 3. In conclusion, we have shown that radical prostatectomy without prior biopsy is safe in terms of the diagnosis of clinically significant PCa when proper preoperative risk stratification involving mpMRI and PSMA-PET imaging is applied.

4 March 2020 in World Journal of Urology
Verified
Journal Article
Open access
PDF file
Alexander KretschmerAlexander Kretschmer
Alexander Kretschmer
RBRobert Bischoff
Robert Bischoff
MCMichael Chaloupka
Michael Chaloupka
FJFriedrich Jokisch
Friedrich Jokisch
TWThilo Westhofen
Thilo Westhofen
CSChristian G. Stief
Christian G. Stief
Purpose: Introduction of robot-assisted radical prostatectomy (RARP) has revolutionized the therapeutic landscape of organ-confined prostate cancer (PCa). However, comparative analyses focused on health-related quality of life (HRQOL) after RARP and open retropubic prostatectomy (ORP) are sparse. Methods: In the current retrospective analysis,inclusion criteria encompassed PSA ≤ 10 ng/ml, ≤ pT2c, ISUP ≤ 3, age ≤ 65 years, and preoperative continence. A propensity score-matched patient cohort [n = 418 (ORP: 209, RARP: 209)] was created and HRQOL was prospectively assessed based on validated questionnaires (EORTC QLQ-C30) preoperatively, 3 months, 12 months, and 24 months postoperatively. Primary endpoint was good general HRQOL based on previously published cut-off values. Erectile function was measured via IIEF-5, urinary continence via ICIQ-SF questionnaire. Multivariable analysis included binary logistic regression models (p < 0.05). Results: Open retropubic prostatectomy and RARP cohorts were well balanced. General HRQOL was significantly higher for ORP compared to RARP after 3 months (70.1 vs. 61.6, p = 0.001), but not at the remaining follow-up time points. There were no significant differences for the remaining QLQ-C30 functioning and symptom scores. In multivariable analysis stratified for IIEF-5 and ICIQ-SF scores and surgeon experience, RARP could be confirmed as a marginally independent predictor for lower ratios of good general HRQOL after 3 months (OR 0.464, 95% CI 0.215–0.999; p = 0.050) without any differences at the remaining time points. Conclusions: The current study addresses various HRQOL outcomes over a postoperative period of up to 2 years in a homogenous propensity score-matched contemporary cohort. Marginally better general HRQOL outcomes could be detected for ORP compared to RARP 3 months postoperatively.

16 December 2022 in Cells
Verified
Journal Article
Open access
PDF file
Elif AkovaElif Akova
Elif Akova
AAAttila Aszodi
Attila Aszodi
HTHanna Taipaleenmäki
Hanna Taipaleenmäki
HSHiroaki Saito
Hiroaki Saito
VSVeronika Schönitzer
Veronika Schönitzer
Maximilian SallerMaximilian Saller
Maximilian Saller
Prostate cancer bone metastasis is still one of the most fatal cancer diagnoses for men. Survival of the circulating prostate tumor cells and their adaptation strategy to survive in the bone niche is the key point to determining metastasis in early cancer stages. The promoter of SFRP2 gene, encoding a WNT signaling modulator, is hypermethylated in many cancer types including prostate cancer. Moreover, SFRP2 can positively regulate osteogenic differentiation in vitro and in vivo. Here, we showed SFRP2 overexpression in the prostate cancer cell line PC3 induces an epithelial mesenchymal transition (EMT), increases the attachment, and modifies the transcriptome towards an osteoblast-like phenotype (osteomimicry) in a collagen 1-dependent manner. Our data reflect a novel molecular mechanism concerning how metastasizing prostate cancer cells might increase their chance to survive within bone tissue.

11 November 2021 in Cancers
Verified
Journal Article
Open access
PDF file
MCMichael Chaloupka
Michael Chaloupka
LSLina Stoermer
Lina Stoermer
MAMaria Apfelbeck
Maria Apfelbeck
ABAlexander Buchner
Alexander Buchner
VWVera Wenter
Vera Wenter
Alexander KretschmerAlexander Kretschmer
Alexander Kretschmer
(1) Background: local treatment of the primary tumor has become a valid therapeutic option in de-novo oligo-metastatic prostate cancer (PC). However, evidence regarding radical prostatectomy (RP) in this setting is still subpar, and the effect of cytoreductive RP on postoperative health-related quality of life (HRQOL) is still unclear. (2) Methods: for the current study, patients with de-novo oligo-metastatic PC (cM1-oligo), defined as ≤5 bone lesions in the preoperative staging, were included, and matched cohorts using the variables age, body-mass index (BMI), and pT-stage were generated. Patient-reported outcome measures (PROMS) were assessed pre- and postoperatively using the validated EORTC-QLQ-C30, IIEF-5, and ICIQ-SF questionnaires. The primary endpoint for univariate and multivariable analysis was good general HRQOL defined by previously validated cut-off values. (3) Results: in total, 1268 patients (n = 84 (7%) cM1-oligo) underwent RP between 2012 and 2020 at one tertiary care center. A matched cohort of 411 patients (n = 79 with oligo-metastatic bone disease (cM1-oligo) and n = 332 patients without clinical indication of metastatic disease (cM0)) was created. The median follow-up was 25mo. There was no significant difference in good general HRQOL rates between cM1-oligo-patients and cM0-patients before RP (45.6% vs. 55.2%, p = 0.186), and at time of follow-up (44% vs. 56%, p = 0.811). Global health status (GHS) worsened significantly in cM0-patients compared to baseline (−5, p = 0.001), whereas GHS did not change significantly in cM1-oligo-patients (+3.2, p = 0.381). In multivariate analysis stratified for good erectile function (IIEF5 > 18; OR 5.722, 95% CI 1.89–17.36, p = 0.002) and continence recovery (OR 1.671, 95% CI 1.03–2.70, p = 0.036), cM1-oligo was not an independent predictive feature for general HRQOL (OR 0.821, 95% CI 0.44–1.53, p = 0.536). (4) Conclusions: in this large contemporary retrospective analysis, we observed no significant difference in HRQOL in patients with the oligometastatic bone disease after cytoreductive radical prostatectomy, when compared to patients with localized disease at time of surgery.

19 April 2025 in BJU International
Verified
Journal Article
Open access
NPNikolaos Pyrgidis
Nikolaos Pyrgidis
MCMichael Chaloupka
Michael Chaloupka
BEBenedikt Ebner
Benedikt Ebner
YVYannic Volz
Yannic Volz
PWPhilipp Weinhold
Philipp Weinhold
MAMaria Apfelbeck
Maria Apfelbeck
Objective: To compare the perioperative complications of the most common focal therapy (FT) modalities for prostate cancer. Patients and Methods: We assessed the GeRmAn Nationwide inpatient Data (GRAND) from 2005 to 2023, provided by the Research Data Center of the Federal Bureau of Statistics. We compared perioperative outcomes of high‐intensity focused ultrasound (HIFU), hyperthermia, irreversible electroporation of the prostate, cryotherapy, vascular photodynamic therapy of the prostate (VTP), and transurethral ultrasound ablation, as well as HIFU vs non‐HIFU treatments in general. Furthermore, we evaluated the role of concomitant transurethral resection of the prostate (TURP) on perioperative complications. Finally, the complication rate of FT was also compared to brachytherapy and robot‐assisted radical prostatectomy. Results: A total of 10 544 underwent FT. Most patients received HIFU (92%). The number of FT cases performed annually has been steadily decreasing. The most prevalent complication (9.6%) was urinary tract infection (HIFU: 10%, hyperthermia: 6.2%, cryotherapy: 6.8%, VTP: 3.9%). Haematuria was observed in 3.6% of all cases. In the multivariable regression, HIFU was associated with higher rates of urinary tract infections (10% vs 5.2%, P < 0.001) but lower rates of haematuria (3.4% vs 5.5%, P < 0.001) and admission to the intensive care unit (0.7% vs 2.2%, P < 0.001) compared to non‐HIFU procedures. Concomitant TURP was associated with higher transfusion ( P < 0.001), haematuria ( P < 0.001), sepsis ( P = 0.001), and urinary retention rates ( P = 0.03). Most perioperative complications were statistically significantly worse in patients undergoing FT compared to brachytherapy, while most perioperative complications were better after FT vs robot‐assisted radical prostatectomy. Conclusions: In the largest epidemiological comparative study on the risk of complications of the most common FT for prostate cancer, we were able to show an overall low risk of perioperative complications.