Dirk O. Bauerschlag

Dr. Dirk O. Bauerschlag

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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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11 May 2023 in Medicina
Verified
Journal Article
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MSMelanie Schubert
Melanie Schubert
DBDirk O. Bauerschlag
Dirk O. Bauerschlag
Mustafa Zelal MuallemMustafa Zelal Muallem
Mustafa Zelal Muallem
NMNicolai Maass
Nicolai Maass
IAIbrahim Alkatout
Ibrahim Alkatout
Cervical cancer is still the fourth most common cancer in women throughout the world; an estimated 604,000 new cases were observed in 2020. Better knowledge of its pathogenesis, gained in recent years, has introduced new preventive and diagnostic approaches. Knowledge of its pathogenesis has made it possible to provide individualized surgical and drug treatment. In industrialized countries, cervical cancer has become a less frequent tumor entity due to the accessibility of the human papilloma virus vaccination, systematic preventive programs/early detection programs, health care infrastructure and the availability of effective therapy options. Nevertheless, globally, neither mortality nor morbidity has been significantly reduced over the past 10 years, and therapy approaches differ widely. The aim of this review is to address recent advances in the prevention, diagnostic investigation and treatment of cervical cancer globally, focusing on advances in Germany, with a view toward providing an updated overview for clinicians. The following aspects are addressed in detail: (a) the prevalence and causes of cervical cancer, (b) diagnostic tools using imaging techniques, cytology and pathology, (c) pathomechanisms and clinical symptoms of cervical cancer and (d) different treatment approaches (pharmacological, surgical and others) and their impact on outcomes.

23 April 2021 in Cancers
Verified
Journal Article
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NHNina Hedemann
Nina Hedemann
AHAndreas Herz
Andreas Herz
JSJan Hendrik Schiepanski
Jan Hendrik Schiepanski
JDJan Dittrich
Jan Dittrich
SSSusanne Sebens
Susanne Sebens
DBDirk O. Bauerschlag
Dirk O. Bauerschlag
Chemotherapy resistance is a major challenge in ovarian cancer (OvCa). Thus, novel treatment combinations are highly warranted. However, many promising drug candidates tested in two-dimensional (2D) cell culture have not proved successful in the clinic. For this reason, we analyzed our drug combination not only in monolayers but also in three-dimensional (3D) tumor spheroids. One potential therapeutic target for OvCa is A disintegrin and metalloprotease 17 (ADAM17). ADAM17 can be activated by chemotherapeutics, which leads to enhanced tumor growth due to concomitant substrate cleavage. Therefore, blocking ADAM17 during chemotherapy may overcome resistance. Here, we tested the effect of the ADAM17 inhibitor GW280264X in combination with cisplatin on ovarian cancer cells in 2D and 3D. In 2D, the effect on five cell lines was analyzed with two readouts. Three of these cell lines formed dense aggregates or spheroids (HEY, SKOV-3, and OVCAR-8) in 3D and the treatment effect was analyzed with a multicontent readout (cytotoxicity, viability, and caspase3/7 activation). We tested the combined therapy on tumor spheroids derived from primary patient cells. In 2D, we found a significant reduction in the half minimal (50%) inhibitory concentration (IC50) value of the combined treatment (GW280264X plus cisplatin) in comparison with cisplatin monotherapy in all five cell lines with both 2D readout assays (viability and caspase activation). In contrast, the combined treatment only showed an IC50 reduction in HEY and OVCAR-8 3D tumor spheroid models using caspase3/7 activity or CelltoxTM Green as the readout. Finally, we found an improved effect of GW280264X with cisplatin in tumor spheroids derived from patient samples. In summary, we demonstrate that ADAM17 inhibition is a promising treatment strategy in ovarian cancer.

23 March 2018 in Oncotarget
Verified
Journal Article
Open access
NHNina Hedemann
Nina Hedemann
CRChristoph Rogmans
Christoph Rogmans
SSSusanne Sebens
Susanne Sebens
DWDaniela Wesch
Daniela Wesch
MRManuel Reichert
Manuel Reichert
DBDirk O. Bauerschlag
Dirk O. Bauerschlag
Chemotherapeutic resistance evolves in about 70 % of ovarian cancer patients and is a major cause of death in this tumor entity. Novel approaches to overcome these therapeutic limitations are therefore highly warranted. A disintegrin and metalloprotease 17 (ADAM17) is highly expressed in ovarian cancer and required for releasing epidermal growth factor receptor (EGFR) ligands like amphiregulin (AREG). This factor has recently been detected in ascites of advanced stage ovarian cancer patients. However, it is not well understood, whether and how ADAM17 might contribute to chemo resistance of ovarian cancer. In this study, we identified ADAM17 as an essential upstream regulator of AREG release under chemotherapeutic treatment in ovarian cancer cell lines and patient derived cells. In the majority of ovarian cancer cells cisplatin treatment resulted in enhanced ADAM17 activity, as shown by an increased shedding of AREG. Moreover, both mRNA and the protein content of AREG were dose-dependently increased by cisplatin exposure. Consequently, cisplatin strongly induced phosphorylation of ADAM17-downstream mediators, the EGFR and extracellular signal-regulated kinases (ERK). Phorbol 12-myristate 13-acetate (PMA), similarly to cisplatin, mediated AREG shedding and membrane fading of surface ADAM17. Inhibition of ADAM17 with either GW280264X or the anti-ADAM17 antibody D1 (A12) as well as silencing of ADAM17 by siRNA selectively reduced AREG release. Thus, ADAM17 inhibition sensitized cancer cells to cisplatin-induced apoptosis, and significantly reduced cell viability. Based on these findings, we propose that targeting of ADAM17 in parallel to chemotherapeutic treatment suppresses survival pathways and potentially diminish evolving secondary chemo resistance mechanisms.

2 February 2021 in Medicina
Verified
Journal Article
Open access
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MEMohamed Elessawy
Mohamed Elessawy
MMM. Mabrouk
M. Mabrouk
THThorsten Heilmann
Thorsten Heilmann
MWMarion Weigel
Marion Weigel
mohamed Hossam zidanmohamed Hossam zidan
mohamed Hossam zidan
DKDina Kamel
Dina Kamel
Background and objectives: The primary objective was to evaluate the benefit of training with virtual reality simulation. The secondary objective was to describe the short-term skill acquisition obtained by simulation training and to determine the factors affecting its magnitude. Materials and Methods: We prospectively performed a three-stage evaluation: face, constructive, and predictive to evaluate the training with a laparoscopic simulator with haptic feedback. The participants (n = 63) were divided according to their level of experience into three groups: 16% residents; 46% specialists and 38% were consultants. Results: Face evaluation demonstrates the acceptance of the design and realism of the tasks; it showed a median score of eight (IQR 3) on a Likert scale and 54% of participants (n = 34) gave the tissue feedback a moderate rating. Constructive evaluation demonstrates the improvement of the participants in the training session and the ability of the designed task to distinguish the experienced from the inexperienced surgeon based on the performance score, at task I (transfer of pegs) and II (laparoscopic salpingectomy). There was an improvement in both tasks with a significant increase in score and reduction in time. The study showed that those with a high score at the pre-test recorded a high score post-test, showing a significant pair-wise comparison (Z) and correlation (p) showing a significant statistical significance (p < 0.001). The predictive evaluation demonstrates the beneficiary effect of training four weeks afterward on the practice of surgeons addressed with five questions. It showed an improvement regarding implementation into daily routine, performance of procedure, suturing, shortening of the operative time, and complication management. Conclusions: Virtual reality simulation established high ratings for both realism and training capacity, including clinical relevance, critical relevance, and maintaining training enthusiasm.

6 November 2021 in Cancers
Verified
Journal Article
Open access
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CRChristoph Rogmans
Christoph Rogmans
Jan Dominik KuhlmannJan Dominik Kuhlmann
Jan Dominik Kuhlmann
GHGerrit Hugendieck
Gerrit Hugendieck
TLTheresa Link
Theresa Link
NANorbert Arnold
Norbert Arnold
NHNina Hedemann
Nina Hedemann
Ovarian cancer has the highest mortality rate among gynecological tumors. This is based on late diagnosis and the lack of early symptoms. To improve early detection, it is essential to find reliable biomarkers. The metalloprotease ADAM17 could be a potential marker, as it is highly expressed in many solid tumors, including ovarian and breast cancer. The aim of this work is to evaluate the relevance of ADAM17 as a potential diagnostic blood-based biomarker in ovarian cancer. Ovarian cancer cell lines IGROV-1 and A2780, as well as primary patient-derived tumor cells obtained from tumor tissue and ascitic fluid, were cultured to analyze ADAM17 abundance in the culture supernatant. In a translational approach, a cohort of 117 well-characterized ovarian cancer patients was assembled and ADAM17 levels in serum and corresponding ascitic fluid were determined at primary diagnosis. ADAM17 was quantified by enzyme-linked immunosorbent assay (ELISA). In the present study, ADAM17 was detected in the culture supernatant of ovarian cancer cell lines and primary cells. In addition, ADAM17 was found in serum and ascites of ovarian cancer patients. ADAM17 level was significantly increased in ovarian cancer patients compared to an age-matched control group (p < 0.0001). Importantly early FIGO I/II stages, which would not have been detected by CA-125, were associated with higher ADAM17 concentrations (p = 0.007). This is the first study proposing ADAM17 as a serum tumor marker in the setting of a gynecological tumor disease. Usage of ADAM17 in combination with CA-125 and other markers could help detect early stages of ovarian cancer.

29 November 2022 in Cancers
Verified
Journal Article
Open access
PDF file
CRChristoph Rogmans
Christoph Rogmans
JFJulia Feuerborn
Julia Feuerborn
LTLeonie Treeck
Leonie Treeck
NTNils Tribian
Nils Tribian
IFInken Flörkemeier
Inken Flörkemeier
NHNina Hedemann
Nina Hedemann
Ovarian cancer is the third most common gynecological malignancy and has the highest mortality rate. Owing to unspecific symptoms, ovarian cancer is not detected until an advanced stage in about two-thirds of cases. Therefore, it is crucial to establish reliable biomarkers for the early stages to improve the patients’ prognosis. The aim of this study is to investigate whether the ADAM17 substrates Nectin-4, Heparin-binding EGF-like growth factor (HB-EGF) and Amphiregulin (AREG) could function as potential tumor markers for ovarian cancer. In this study a set of 231 sera consisting of 131 ovarian cancer patients and 100 healthy age-matched controls were assembled. Nectin-4, HB-EGF and AREG levels of preoperatively collected sera were determined by enzyme-linked immunosorbent assay (ELISA). Our analysis revealed that Nectin-4 and HB-EGF were significantly increased compared to the age-matched control group (p < 0.0001, p = 0.016). Strikingly, significantly higher Nectin-4 and HB-EGF levels were detected in early-stage FIGO I/II (p <0.001; p = 0.025) compared to healthy controls. Eighty-four percent (16/19) of patients with low Ca-125 levels showed increased Nectin-4 levels. Our study proposes Nectin-4 and HB-EGF as promising blood-based biomarkers for the detection of early stages of ovarian cancer patients that would not have been detected by Ca-125.