Klinik und Poliklinik für Urologie
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Clear cell renal cell carcinoma is the most frequent malignant kidney tumor in adults. It is often associated with biallelic VHL mutations. We characterized our cell lines according to their HIF expression pattern. Cell lines RCC4, UOK-220 and CaKi-2 were assigned to subtype H1H2, cell lines 786-O and A-498 were assigned to subtype H2 and cell lines CaKi-1 and Rc-124 were assigned to subtype VHLwt.
Previous work of our group had shown, that p53 can be activated in ccRCC following irradiation but is not able to induce apoptosis. An important link to p53 activity with strong antiapoptotic qualities is the NFB pathway, which can be activated e. g. by irradiation.
We irradiated the three subtypes previously established as well as two control cell lines, SAOS-2 (p53 negative cell line) and HEK 293 (contains functioning p53) with 2 Gy and 10 Gy and analyzed several proteins of the pathway by using western blots. Several target genes with antiapoptotic qualities were analyzed by using rt-PCR.
We found, that out of the cell lines analyzed, both control cell lines (SAOS-2, HEK 293) showed the strongest response (activation of the NFB pathway) following irradiation. Among the three ccRCC subtypes the VHLwt cell lines showed the strongest response. H2 cell lines showed almost no response at all.
A connection between the missing ability of p53 to induce apoptosis and an induction of transcription factors by the NFB pathway could not be determined. We also could not determine biological differences between the subtypes.
We analyzed, whether any NFB proteins were present in the nucleus following irradiation and found, that only p50 homodimers were present in the nucleus. This might point towards p50 homodimers, which have been described to have different characteristics than heterodimers. More research is needed to analyze this important finding.
Introduction: Cisplatin is extensively used in the treatment of head and neck carcinomas. Cetuximab combination therapy is employed in recurrent and metastatic settings. Sunitinib showed positive results in the treatment of head and neck carcinomas, both as monotherapy or in combination with cetuximab. Nonetheless, the mechanism governing these pharmacological interactions is largely unresolved. This study investigates the impact of cetuximab on the cytotoxicity of cisplatin and sunitinib using cells representative of head and neck carcinoma and the oral epithelium.
Methods: The uptake and efflux activities of cells were determined using the prototypical fluorescent substrates 4-[4-[dimethylamino]styryl)-1-methyl pyridinium iodide, Hoechst 33342, and calcein-AM in the presence or absence of specific inhibitors in cells pretreated with cetuximab. The expression of key uptake and efflux drug transporters was analyzed using qPCR and immunofluorescence. Cisplatin and sunitinib cytotoxicities after cetuximab pretreatment were evaluated using the PrestoBlue viability assay.
Results: Both tumor and nontumor cells showed significant active drug transport activity. Cetuximab substantially deregulated the expression of key transporters involved in drug resistance in head and neck cancer cells. Transporter expression in the nontumor cell was unaffected. Upon cetuximab pretreatment, the half maximal effective toxic concentration of cisplatin was reduced by 0.75-fold and sunitinib by 0.82-fold in cancer cells. Nontumor cells were not sensitive to cisplatin or sunitinib under the conditions tested.
Conclusion: Cetuximab regulates the expression and activity of key membrane drug transporters in head and neck cancer cells, involved in drug resistance. The deregulation of the transport mechanism behind cisplatin and sunitinib uptake reverses drug resistance and enhances the cytotoxicity of both drugs.
Organic anion transporters 1 and 3 (OAT1 and OAT3) play a crucial role in kidney function by regulating the secretion of multiple renally cleared small molecules and toxic metabolic by-products. Assessing the activity of these transporters is essential for drug development purposes as they can significantly impact drug disposition and safety. OAT1 and OAT3 are amongst the most abundant drug transporters expressed in human renal proximal tubules. However, their expression is lost when cells are isolated and cultured in vitro, which is a persistent issue across all human and animal renal proximal tubule cell models, including primary cells and cell lines. Although it is well known that the overall expression of drug transporters is affected in vitro, the underlying reasons for the loss of OAT1 and OAT3 are still not fully understood. Nonetheless, research into the regulatory mechanisms of these transporters has provided insights into the molecular pathways underlying their expression and activity. In this review, we explore the regulatory mechanisms that govern the expression and activity of OAT1 and OAT3 and investigate the physiological changes that proximal tubule cells undergo and that potentially result in the loss of these transporters. A better understanding of the regulation of these transporters could aid in the development of strategies, such as introducing microfluidic conditions or epigenetic modification inhibitors, to improve their expression and activity in vitro and to create more physiologically relevant models. Consequently, this will enable more accurate assessment for drug development and safety applications.
The study of prostate cancer in vitro relies on established cell lines that lack important physiological characteristics, such as proper polarization and expression of relevant biomarkers. Microphysiological systems (MPS) can replicate cancer microenvironments and lead to cellular phenotypic changes that better represent organ physiology in vitro. In this study, we developed an MPS model comprising conventional prostate cancer cells to evaluate their activity under dynamic culture conditions. Androgen-sensitive (LNCaP) and androgen-insensitive (PC3) cells were grown in conventional and 3D cultures, both static and dynamic. Cell morphology, the secretion of prostate-specific antigen, and the expression of key prostate markers and microRNAs were analyzed. LNCaP formed spheroids in 3D and MPS cultures, with morphological changes supported by the upregulation of cytokeratins and adhesion proteins. LNCaP also maintained a constant prostate-specific antigen secretion in MPS. PC3 cells did not develop complex structures in 3D and MPS cultures. PSA expression at the gene level was downregulated in LNCaP-MPS and considerably upregulated in PC3-MPS. MicroRNA expression was altered by the 3D static and dynamic culture, both intra- and extracellularly. MicroRNAs associated with prostate cancer progression were mostly upregulated in LNCaP-MPS. Overall dynamic cell culture substantially altered the morphology and expression of LNCaP cells, arguably augmenting their prostate cancer phenotype. This novel approach demonstrates that microRNA expression in prostate cancer cells is sensitive to external stimuli and that MPS can effectively promote important physiological changes in conventional prostate cancer models.
Simple Summary
This German multicenter study investigated the importance of different supportive measures offered to patients with prostate cancer who undergo surgery (radical prostatectomy). A number of these supportive measures are required during the certification of a urologic hospital as prostate cancer center. However, a broad scientific basis evaluating these measures from the patient’s perspective is still lacking. In this study, patients were asked to rate the relevance of several supportive measures and to estimate the effective availability of these different supportive measures at their urologic clinic about 15 months after surgery. Our study highlights that only six of fifteen different supportive measures were rated as very relevant by patients. None of these six supportive measures were offered more intensively at the certified clinics compared to the non-certified clinics according to the patients. Our study helps to identify those supportive measures with the highest subjective impact on patients in this setting.
Abstract
Certification as a prostate cancer center requires the offer of several supportive measures to patients undergoing radical prostatectomy (RP). However, it remains unclear how patients estimate the relevance of these measures and whether the availability of these measures differs between certified prostate cancer centers (CERTs) and non-certified centers (NCERTs). In 20 German urologic centers, a survey comprising questions on the relevance of 15 supportive measures was sent to 1000 patients at a median of 15 months after RP. Additionally, patients were asked to rate the availability of these measures using a four-item Likert scale. The aim of this study was to compare these ratings between CERTs and NCERTs. The response rate was 75.0%. In total, 480 patients underwent surgery in CERTs, and 270 in NCERTs. Patients rated 6/15 supportive measures as very relevant: preoperative medical counselling concerning treatment options, a preoperative briefing answering last questions, preoperative pelvic floor exercises (PFEs), postoperative PFEs, postoperative social support, and postoperative rehabilitation addressing physical fitness recovery. These ratings showed no significant difference between CERTs and NCERTs (p = 0.133–0.676). In addition, 4/9 of the remaining criteria were rated as more detailed by patients in CERTs. IMPROVE represents the first study worldwide to evaluate a patient-reported assessment of the supportive measures accompanying RP. Pertinent offers vary marginally between CERTs and NCERTs.
Introduction
Medical gas plasma therapy has been successfully applied to several types of cancer in preclinical models. First palliative tumor patients suffering from advanced head and neck cancer benefited from this novel therapeutic modality. The gas plasma-induced biological effects of reactive oxygen and nitrogen species (ROS/RNS) generated in the plasma gas phase result in oxidation-induced lethal damage to tumor cells.
Objectives
This study aimed to verify these anti-tumor effects of gas plasma exposure on urinary bladder cancer.
Methods
2D cell culture models, 3D tumor spheroids, 3D vascularized tumors grown on the chicken chorion-allantois-membrane (CAM) in ovo, and patient-derived primary cancer tissue gas plasma-treated ex vivo were used.
Results
Gas plasma treatment led to oxidation, growth retardation, motility inhibition, and cell death in 2D and 3D tumor models. A marked decline in tumor growth was also observed in the tumors grown in ovo. In addition, results of gas plasma treatment on primary urothelial carcinoma tissues ex vivo highlighted the selective tumor-toxic effects as non-malignant tissue exposed to gas plasma was less affected. Whole-transcriptome gene expression analysis revealed downregulation of tumor-promoting fibroblast growth factor receptor 3 (FGFR3) accompanied by upregulation of apoptosis-inducing factor 2 (AIFm2), which plays a central role in caspase-independent cell death signaling.
Conclusion
Gas plasma treatment induced cytotoxicity in patient-derived cancer tissue and slowed tumor growth in an organoid model of urinary bladder carcinoma, along with less severe effects in non-malignant tissues. Studies on the potential clinical benefits of this local and safe ROS therapy are awaited.
Modulation der biologischen Wirkung von MikroRNA-1 mittels chemischer Modifikation des RNA-Moleküls
(2021)
In vielen Malignitäten kann eine Dysregulation von miR beobachtet werden. Die reduzierte Expression dieser kleinen, nicht-codierenden RNA resultiert in verlängertem Tumorüberleben, einer gesteigerten Proliferationsrate, verbesserter Angiogenese und Metastasierung von Tumorzellen [1, 2]. Da miR-1 in ihrer Funktion als Tumorsuppressor mehrere onkogene Signal- und Effektorkaskaden supprimieren kann, ist die Erforschung ihres therapeutischen Potenzials von gesteigertem Interesse [1]. Dies zu realisieren eignen sich Prostatakarzinomzellen in besonderem Maße, da dort endogene miR-1 enorm herunterreguliert ist [157].
Die vorliegende Arbeit untersuchte die miR-1 Re-Expressionstherapie zur Hemmung der Tumorprogression auf molekularer Ebene an Prostatakarzinomzellen mit synthetischen miR-1 Molekülen. Darüber hinaus wurde die synthetische miR-1 durch unterschiedliche Substituenten modifiziert, um zu evaluieren ob diese Modifikationen Einfluss auf die biologische Wirkung auf die untersuchten Prostatakarzinomzelllinien haben. Ein weiterer Fokus lag dabei auf der Fragestellung, ob die Position und die chemischen Eigenschaften der Substituenten selbst einen Einfluss auf die miR-1 Effekte ausüben.
Es konnte gezeigt werden, dass die Wiederherstellung der intrazellulären miR-1 Spiegel durch die unmodifizierte, synthetische miR-1 bereits einen hemmenden Effekt auf das Tumorwachstum hatte. Ausserdem deuten die Ergebnisse darauf hin, dass die chemisch synthetisierte und modifizierte miR-1, der unveränderten, synthetischen miR-1 in ihrer tumorsupprimierenden Funktion überlegen sein kann.
Die antiproliferative Wirksamkeit der modifizierten miR-1 Moleküle hing jedoch eher von der Position, als von der Art des modifizierten Nukleotids ab. Es konnte gezeigt werden, dass, unabhängig vom Substituenten, Modifikationen an vermutlich kritischen Positionen sogar ein gesteigertes Tumorwachstum zur Folge hatten. Substituenten an ungünstigen Positionen konnten zu Reduktion der antiproliferativen Effekte von miR-1-Molekülen und somit sogar zu vermehrten Tumorwachstum führen. Dies bietet die Möglichkeit, durch die Auswahl gut charakterisierter miR mit hohem antiproliferativem Potenzial maßgeschneiderte, synthetisch modifizierte miR für die zukünftige, individualisierte Therapie verschiedener Krebsentitäten zu entwickeln.
An Serin139 phosphoryliertes gamma Histon H2A.X (γH2A.X) hat sich über die Jahrzehnte als sensitiver Surrogat-Endpunkt Strahlen-induzierter DNA-Schäden, insbesondere von DNA-Doppelstrangbrüchen (DSBs) etabliert. Daher wurde γH2A.X in seiner biomedizinischen Anwendung als geeigneter Marker und genereller Indikator direkter DNA-Schäden anderer Agenzien, beispielsweise niedrig konzentrierter primär exogener reaktiver Sauerstoffspezies (ROS), deren intrazelluläre Effekte weniger direkt auf eine DNA-Oxidation oder das Einfügen von Strangbrüchen abzielen, angesehen. Nicht-thermisches physikalisches Plasma (NTPP), ein teilweise ionisiertes Gas, dessen biochemische Wirkung in vitro hauptsächlich über Freisetzung reaktiver Sauerstoff- und Stickstoffspezies (RONS) in der flüssigen Phase der Zellumgebung vermittelt wird, setzt lebende Systeme dosisabhängig oxidativem Stress aus und wird therapeutisch in der Wundbehandlung sowie Krebsbehandlung angewendet. Die γH2A.X Quantifizierung wurde häufig zur Beurteilung der Genotoxizität in Plasma-behandelten Zellen verwendet, wobei die NTPP-Exposition in vitro bereits häufig einen γH2A.X Anstieg zeigte, was zu der Hypothese führte, dass ein (oxidativer) DNA-Schaden die direkte Konsequenz Plasma-generierter ROS sei. Darüber hinaus tritt γH2A.X auch während der Apoptose auf, die wiederum selbst mit der NTPP- und ROS-Exposition assoziiert ist. Die vorliegende Arbeit untersuchte die γH2A.X-Induktion in einer Lymphoblasten-Zelllinie bei ROS-Exposition (NTPP, H2O2 oder HOCl) bzw. Behandlung mit UVB-Licht. Durch Verwendung von Antioxidantien wurden sowohl die Zytotoxizität als auch die γH2A.X-Induktion bei allen Arten der ROS-Quellen außer bei UVB-Strahlung aufgehoben. Inhibition der Signalwege für oxidativen Stress (p38-MAPK) und Apoptose (Pan-Caspase) hemmten signifikant die γH2A.X-Induktion bei ROS, jedoch nicht bei UVB-Licht. Letztlich und trotz H2A.X Phosphorylierung führte die UVB-Licht- und eben nicht die NTPP-Exposition zu einer signifikanten Bildung von Mikronuklei (MN), die einen funktionellen Endpunkt genotoxischer DSBs darstellen, sodass trotz der γH2A.X Präsenz kein nachhaltiges mutagenes Potential der medizinischen Plasmabehandlung identifiziert werden konnte. Im Gegensatz zu Strahlen- oder Chemotherapeutika- induziertem und somit DNA-Schaden-assoziiertem γH2A.X zeigen die Daten dieser Arbeit die H2A.X Phosphorylierung weniger als Folge eines ROS-vermittelten primären DNA-Schadens, sondern vielmehr im Licht redox-sensitiver Signalwege der Apoptose, sodass künftige γH2A.X Messungen im medizinischen Bereich, insbesondere in der Plasmamedizin und Redoxbiologie einer sorgfältigen Interpretation bedürfen.
Leukocyte telomere length (TL) has been suggested as a marker of biological age in healthy
individuals, but can also reflect inherited and acquired hematopoietic dysfunctions or indicate an
increased turnover of the hematopoietic stem and progenitor cell compartment. In addition, TL is able
to predict the response rate of tyrosine kinase inhibitor therapy in chronic myeloid leukemia (CML),
indicates clinical outcomes in chronic lymphocytic leukemia (CLL), and can be used as screening tool
for genetic sequencing of selected genes in patients with inherited bone marrow failure syndromes
(BMFS). In tumor cells and clonal hematopoietic disorders, telomeres are continuously stabilized by
reactivation of telomerase, which can selectively be targeted by telomerase-specific therapy. The use of
the telomerase inhibitor Imetelstat in patients with essential thrombocythmia or myelofibrosis as well
as the use of dendritic cell-based telomerase vaccination in AML patients with complete remissions are
promising examples for anti-telomerase targeted strategies in hematologic malignancies. In contrast,
the elevation in telomerase levels through treatment with androgens has become an exciting clinical
intervention for patients with BMFS. Here, we review recent developments, which highlight the
impact of telomeres and telomerase targeted therapies in hematologic dysfunctions.
Definition
Microphysiological systems (MPSs) are in vitro models that can incorporate dynamic stimuli such as flow, pressure and contraction in cell culture, enabling the formation of cellular architectures and retrieving physiological function often absent in conventional 2D-cell culture. MPS applications saw a substantial growth in recent years, drawing attention from industry as a strategy to optimize pre-clinical drug-development purposes, as well as from biomedical research, to fill a gap between in vivo and in vitro models. Several MPS platforms are now available and are employed in the development of bone and kidney complex systems for urologic and orthopaedic research. These advances have enabled, for example, the in vitro modelling of bone regeneration and renal drug secretion, and have dramatic potential to improve research into both orthopaedic and urology cancers.