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9
result(s) for
"Wakileh, Gamal A."
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Profiling the 3D interaction between germ cell tumors and microenvironmental cells at the transcriptome and secretome level
2022
The tumor microenvironment (TM), consisting of the extracellular matrix (ECM), fibroblasts, endothelial cells, and immune cells, might affect tumor invasiveness and the outcome of standard chemotherapy. This study investigated the cross talk between germ cell tumors (GCT) and surrounding TM cells (macrophages, T‐lymphocytes, endothelial cells, and fibroblasts) at the transcriptome and secretome level. Using high‐throughput approaches of three‐dimensional (3D) co‐cultured cellular aggregates, this study offers newly identified pathways to be studied with regard to sensitivity toward cisplatin‐based chemotherapy or tumor invasiveness as a consequence of the cross talk between tumor cells and TM components. Mass‐spectrometry‐based secretome analyses revealed that TM cells secreted factors involved in ECM organization, cell adhesion, angiogenesis, and regulation of insulin‐like growth factor (IGF) transport. To evaluate direct cell–cell contacts, green fluorescent protein (GFP)‐expressing GCT cells and mCherry‐expressing TM cells were co‐cultured in 3D. Afterward, cell populations were separated by flow cytometry and analyzed by RNA sequencing. Correlating the secretome with transcriptome data indicated molecular processes such as cell adhesion and components of the ECM being enriched in most cell populations. Re‐analyses of secretome data with regard to lysine‐ and proline‐hydroxylated peptides revealed a gain in proteins, such as collagens and fibronectin. Cultivation of GCT cells on collagen I/IV‐ or fibronectin‐coated plates significantly elevated adhesive and migratory capacity, while decreasing cisplatin sensitivity of GCT cells. Correspondingly, cisplatin sensitivity was significantly reduced in GCT cells under the influence of conditioned medium from fibroblasts and endothelial cells. This study sheds light on the cross talk between GCT cells and their circumjacent TM, which results in deposition of the ECM and eventually promotes a pro‐tumorigenic environment through enhanced migratory and adhesive capacity, as well as decreased cisplatin sensitivity. Hence, our observations indicate that targeting the ECM and its cellular components might be a novel therapeutic option in combination with cisplatin‐based chemotherapy for GCT patients. This study evaluated the interaction between germ cell tumors and their surrounding microenvironment. As such, the secretome has been analyzed to identify secreted factors, while transcriptome‐wide changes upon direct cell–cell interaction by means of 3D co‐cultures determined the deregulated gene sets. Subsequently, in vitro analyses were performed to validate the findings.
Journal Article
The signal transducer CD24 suppresses the germ cell program and promotes an ectodermal rather than mesodermal cell fate in embryonal carcinomas
2022
Testicular germ cell tumors (GCTs) are stratified into seminomas and nonseminomas. Seminomas share many histological and molecular features with primordial germ cells, whereas the nonseminoma stem cell population—embryonal carcinoma (EC)—is pluripotent and thus able to differentiate into cells of all three germ layers (teratomas). Furthermore, ECs are capable of differentiating into extra‐embryonic lineages (yolk sac tumors, choriocarcinomas). In this study, we deciphered the molecular and (epi)genetic mechanisms regulating expression of CD24, a highly glycosylated signaling molecule upregulated in many cancers. CD24 is overexpressed in ECs compared with other GCT entities and can be associated with an undifferentiated pluripotent cell fate. We demonstrate that CD24 can be transactivated by the pluripotency factor SOX2, which binds in proximity to the CD24 promoter. In GCTs, CD24 expression is controlled by epigenetic mechanisms, that is, histone acetylation, since CD24 can be induced by the application histone deacetylase inhibitors. Vice versa, CD24 expression is downregulated upon inhibition of histone methyltransferases, E3 ubiquitin ligases, or bromodomain (BRD) proteins. Additionally, three‐dimensional (3D) co‐cultivation of EC cells with microenvironmental cells, such as fibroblasts, and endothelial or immune cells, reduced CD24 expression, suggesting that crosstalk with the somatic microenvironment influences CD24 expression. In a CRISPR/Cas9 deficiency model, we demonstrate that CD24 fulfills a bivalent role in differentiation via regulation of homeobox, and phospho‐ and glycoproteins; that is, it is involved in suppressing the germ cell/spermatogenesis program and mesodermal/endodermal differentiation, while poising the cells for ectodermal differentiation. Finally, blocking CD24 by a monoclonal antibody enhanced sensitivity toward cisplatin in EC cells, including cisplatin‐resistant subclones, highlighting CD24 as a putative target in combination with cisplatin. This study presents the (epi)genetic mechanisms regulating the expression of the signaling transducer CD24 in embryonal carcinoma (EC), a germ cell tumor subtype with embryonic stem cell‐like features. We demonstrated that CD24 expression can be transactivated by the pluripotency factor SOX2 and is involved in suppressing the germ cell program during formation of ECs, while promoting ectodermal differentiation.
Journal Article
Molecular characterization of the CXCR4 / CXCR7 axis in germ cell tumors and its targetability using nanobody-drug-conjugates
2023
Being stimulated by the chemokine CXCL12, the CXCR4 / CXCR7 cascade is involved in tumor proliferation, migration, and metastasis. The interaction between CXCL12, secreted by cells from the microenvironment, and its receptors is complex and has been ascribed to promote chemotherapy resistance. However, the role of this signaling axis and its targetability in germ cell tumors (GCT) is not fully understood. Thus, this study investigated the therapeutic efficacy of a nanobody-drug-conjugate targeting CXCR4 (CXCR4-NDC) and functionally characterized this signaling pathway in GCT using small molecule inhibitors and nanobodies. As shown by diminished cell viability, enhanced apoptosis induction, and detection of mitotic catastrophes, we confirmed the cytotoxic efficacy of the CXCR4-NDC in CXCR4
+
-GCT cells (i.e. seminoma and yolk-sac tumor), while non-malignant CXCR4
−
-fibroblasts, remained largely unaffected. Stimulation of CXCR4
+
/ CXCR7
+
-GCT cells with CXCL12 resulted in an enhanced proliferative and migratory capacity, while this effect could be reverted using CXCR4 inhibitors or a CXCR7-nanobody. Molecularly, the CXCR4 / CXCR7-signaling cascade could be activated independently of MAPK (ERK1 / 2)-phosphorylation. Although, in CXCR4
−
/ CXCR7
−
-embryonal carcinoma cells,
CXCR7
-expression was re-induced upon inhibition of ERK1 / 2-signaling. This study identified a nanobody-drug-conjugate targeting CXCR4 as a putative therapeutic option for GCT, i.e. seminoma and yolk-sac tumors. Furthermore, this study shed light on the functional role of the CXCR4 / CXCR7 / CXCL12-signaling cascade in GCT, demonstrating an important influence on proliferation and migration.
Journal Article
Therapeutical interference with the epigenetic landscape of germ cell tumors: a comparative drug study and new mechanistical insights
by
Köhrer, Karl
,
Stephan, Alexa
,
Wakileh, Gamal A.
in
Adolescent
,
Adult
,
Antineoplastic Agents - therapeutic use
2022
Background
Type II germ cell tumors (GCT) are the most common solid cancers in males of age 15 to 35 years. Treatment of these tumors includes cisplatin-based therapy achieving high cure rates, but also leading to late toxicities. As mainly young men are suffering from GCTs, late toxicities play a major role regarding life expectancy, and the development of therapy resistance emphasizes the need for alternative therapeutic options. GCTs are highly susceptible to interference with the epigenetic landscape; therefore, this study focuses on screening of drugs against epigenetic factors as a treatment option for GCTs.
Results
We present seven different epigenetic inhibitors efficiently decreasing cell viability in GCT cell lines including cisplatin-resistant subclones at low concentrations by targeting epigenetic modifiers and interactors, like histone deacetylases (Quisinostat), histone demethylases (JIB-04), histone methyltransferases (Chaetocin), epigenetic readers (MZ-1, LP99) and polycomb-repressive complexes (PRT4165, GSK343). Mass spectrometry-based analyses of the histone modification landscape revealed effects beyond the expected mode-of-action of each drug, suggesting a wider spectrum of activity than initially assumed. Moreover, we characterized the effects of each drug on the transcriptome of GCT cells by RNA sequencing and found common deregulations in gene expression of ion transporters and DNA-binding factors. A kinase array revealed deregulations of signaling pathways, like cAMP, JAK-STAT and WNT.
Conclusion
Our study identified seven drugs against epigenetic modifiers to treat cisplatin-resistant GCTs. Further, we extensively analyzed off-target effects and modes-of-action, which are important for risk assessment of the individual drugs.
Journal Article
Contemporary options and future perspectives: three examples highlighting the challenges in testicular cancer imaging
by
Ruf, Christian
,
Lisson Catharina
,
Wakileh Gamal Anton
in
Computed tomography
,
Lymph nodes
,
Magnetic resonance imaging
2022
PurposeOne of the main issues in testicular germ cell tumors (TGCTs) management is to reduce the necessary amount of treatment to achieve cure. Excess treatment burden may arise from late diagnosis of the primary as well as from false positive or negative staging results. Correct imaging is of paramount importance for successful management of TGCT. The aim of this review is to point out the current state of the art as well as innovative developments in TGCT imaging on the basis of three common challenging clinical situations.MethodsA selective literature search was performed in PubMed, Medline as well as in recent conference proceedings.ResultsRegarding small testicular lesions, recent studies using elastography, contrast-enhanced ultrasound or magnetic resonance imaging (MRI) showed promising data for differentiation between benign and malignant histology. For borderline enlarged lymph nodes FDG-PET-CT performance is unsatisfactory, promising new techniques as lymphotropic nanoparticle-enhanced MRI is the subject of research in this field. Regarding the assessment of postchemotherapeutic residual masses, the use of conventional computerized tomography (CT) together with serum tumor markers is still the standard of care. To avoid overtreatment in this setting, new imaging modalities like diffusion-weighted MRI and radiomics are currently under investigation. For follow-up of clinical stage I TGCTs, the use of MRI is non-inferior to CT while omitting radiation exposure.ConclusionFurther efforts should be made to refine imaging for TGCT patients, which is of high relevance for the guidance of treatment decisions as well as the associated treatment burdens and oncological outcomes.
Journal Article
Hemorrhagic shock induces renal complement activation
by
Radermacher, Peter
,
Schultze, Anke
,
Wakileh, Gamal
in
Emergency medical care
,
Health risk assessment
,
Hemodynamics
2021
PurposeComplement is activated in hemorrhagic shock and protective effects by specific complement inhibition were shown. However, it remains unclear if complement activation contributes to the local tissue damage and organ failure. Zonulin is known to activate complement and affect organ failure. Therefore, local and systemic complement activation during hemorrhagic shock and its consequences on zonulin were examined.MethodsPorcine hemorrhagic shock (n = 9) was initiated with mean arterial blood pressure maintained constant for 4 h before retransfusion. Before, 4 h after hemorrhage and 12 and 22 h after resuscitation, central and renal blood samples were drawn. Analysis included HMGB-1, C3a, and zonulin (blood and kidney homogenisates) as well as terminal complement complex (TCC) and CH50 (blood). Organ samples were taken for histological and immunohistochemical analyses (C3c).ResultsHMGB-1 was significantly elevated in plasma 4 h after hemorrhagic shock and in homogenized kidneys. TCC after 12 h was significantly elevated centrally, while renal levels were not altered. In contrast, CH50 showed diminished renal values, while normal central levels were observed. Local complement activation was observed with enhanced C3c deposition in kidneys. Zonulin showed significantly diminished levels at 12 and 22 h after hemorrhagic shock (central and renal) and significantly correlated with levels of CH50 and neutrophil gelatinase-associated lipocalin (NGAL).ConclusionThe more pronounced complement activation centrally might indicate consumption of complement products in kidney tissue, which is underlined by C3c staining. Together with diminished levels of zonulin in both systemic and local samples, results could indicate the involvement of complement as well as zonulin in acute kidney failure.
Journal Article
Analysis of performance factors in 240 consecutive cases of robot-assisted flexible ureteroscopic stone treatment
2021
Flexible ureteroscopy is the keystone of modern kidney stone treatment. Although a simple surgical technique achieves good clinical results and a low complication rate, there are high demands on the surgeon’s dexterity and ergonomic restrictions. Robotic-assisted flexible ureteroscopy (rfURS) could overcome these limitations. After 4 years of use of rfURS at a tertiary stone center, performance factors were analyzed to define the role of rfURS in kidney stone management. A rfURS system was installed in August 2014 at the SLK Kliniken (Heilbronn, Germany). Treatment data of
N
= 240 consecutive patients undergoing rfURS were prospectively collected and analyzed. The patient cohort represents typical stone formers.
N
= 240 renal units containing 443 stones with an average stone load of 1798 mm
3
were treated. Surgical parameters as well as the peri- and postoperative complications were recorded, analyzed and compared to the current data in the literature. OR time 91 min, stone treatment time 55 min, stone treatment efficacy 33 mm
3
/min; perioperative complications 5.4%; robot times: preparation 5 min, docking 5 min, console time to stone contact 6 min, console time 75 min; postoperative complications 6.7%; postoperative length of stay 1.5 days; stone-free rate (residuals < 2 mm) 90% and re-treatment rate 8.75%. This consecutive series represents real-life data about the utilization of rfURS. The detailed analysis of performance factors revealed the successful utilization of the first generation of robotic systems in endourologic stone surgery, and indicates that the robot performs comparably to conventional flexible URS. Optimal ergonomics maintain the surgeon’s endurance in long-lasting surgeries.
Journal Article
Guideline-adherence in the treatment of symptomatic urolithiasis in children and adolescents in southwestern Germany
by
Klein, Jan-Thorsten
,
Humke, Ulrich
,
Wakileh, Gamal Anton
in
Adolescent
,
Adolescents
,
Care and treatment
2020
Background
Approximately 1% of urolithiasis cases in Germany affect children. Interdisciplinary groups have agreed on national and international guidelines for children to recommend appropriate treatment pathways. The aim of this retrospective and preliminary study is to analyze whether adherence to current guidelines for pediatric stone disease in southwestern Germany is feasible.
Methods
During 2014 to 2017 24 children and adolescents (nine female, 15 male, median age 9.7 years), were treated for symptomatic urolithiasis in our institutions. We retrospectively collected clinical and operative courses. Clinical pathways were compared to previous guideline recommendations of the EAU 2014 and the German S2k guideline 2015.
Results
17 of the 24 patients were treated according to guideline recommendations (71%). Non-adherency was based on parental decisions in two and technical/medical considerations in five cases. In 11 children (45.8%) secondary or adjunctive treatments were necessary, in three of the seven non-adherently treated (43%) and in eight of the 17 adherently treated children (47%).
Conclusion
Our daily treatment approach seems to comply well with current pediatric stone guidelines. Nevertheless, guideline-non-adherent decision making emphasizes their strength and limitations, as specific clinical situations in children may require an individual treatment plan, as non-predictable conditions may occur.
Journal Article
A Novel Tissue and Stem Cell Specific TERF1 Splice Variant Is Downregulated in Tumour Cells
by
Najjar, Gregoire
,
Zengerling, Friedemann
,
Morcos, Yousef Ashraf Tawfik
in
Amino acids
,
Animals
,
Cell Line, Tumor
2019
In this study, we describe the identification of a novel splice variant of TERF1/PIN2, one of the main components of the telomeric shelterin complex. This new splice variant is identical to TERF1, apart from a 30 amino acid internal insertion near to the C-terminus of TERF1. Based on genome comparison analyses and RNA expression data, we show that this splice variant is conserved among hominidae but absent from all other species. RNA expression and histological analyses show specific expression in human spermatogonial and hematopoietic stem cells (HSCs), while all other analyzed tissues lack the expression of this TERF1-isoform, hence the name TERF1-tsi (TERF1-tissue-specific-isoform). In addition, we could not detect any expression in primary human cells and established cancer cell lines. Immunohistochemistry results involving two new rabbit polyclonal antibodies, generated against TERF1-tsi specific peptides, indicate nuclear localization of TERF1-tsi in a subset of spermatogonial stem cells. In line with this observation, immunofluorescence analyzes in various cell lines consistently revealed that ectopic TERF1-tsi localizes to the cell nucleus, mainly but not exclusively at telomeres. In a first attempt to evaluate the impact of TERF1-tsi in the testis, we have tested its expression in normal testis samples versus matched tumor samples from the same patients. Both RT-PCR and IHC show a specific downregulation of TERF1-tsi in tumor samples while the expression of TERF1 and PIN2 remains unchanged.
Journal Article