Adenosine receptor 2B activity promotes autonomous growth, migration as well as vascularization of head and neck squamous cell carcinoma cells

Adenosine is a signaling molecule that exerts dual effects on tumor growth: while it inhibits immune cell function and thereby prevents surveillance by the immune system, it influences tumorigenesis directly via activation of adenosine receptors on tumor cells at the same time. However, the adenosine-mediated mechanisms affecting oncogenic processes particularly in head and neck squamous cell carcinomas (HNSCC) are not fully understood. Here, we investigated the role of adenosine receptor activity on HNSCC-derived cell lines. Targeting the adenosine receptor A2B (ADORA2B) on these cells with the inverse agonist/antagonist PSB-603 leads to inhibition of cell proliferation, transmigration as well as VEGFA secretion in vitro. At the molecular level, these effects were associated with cell cycle arrest as well as the induction of the apoptotic pathway. In addition, shRNA-mediated downmodulation of ADORA2B expression caused decreased proliferation. Moreover, in in vivo xenograft experiments, chemical and genetic abrogation of ADORA2B activity impaired tumor growth associated with decreased tumor vascularization. Together, our findings characterize ADORA2B as a crucial player in the maintenance of HNSCC and, therefore, as a potential therapeutic target for HNSCC treatment

Analyse des Einflusses von Adenosin auf Plattenepithelkarzinomzelllinien etabliert von Tumoren des Kopf-Hals-Bereiches

Plattenepithelkarzinome des Kopf-Hals-Bereiches - auch HNSCC genannt (engl. head and neck squamous cell carcinoma) - stellen eine schwerwiegende neoplastische Erkrankung mit globaler Prävalenz dar und gehören zu den sechsthäufigsten Krebserkrankungen in der männlichen Population weltweit. Trotz etablierter Therapieregime bestehend aus Chirurgie, Radiatio und Chemotherapie beträgt die 5-Jahres-Überlebensrate nur ca. 50%, welche häufig auf lokoregionäre Rezidive oder Fernmetastasierungen auf Grund einer späten Diagnosestellung in fortgeschrittenen Stadien zurückzuführen ist. Gerade für diese fortgeschrittenen Stadien werden daher dringend neue Therapieansätze benötigt. Im aktuellen Forschungsinteresse steht dabei die Immuntherapie, welche die durch den Tumor unterhaltende Evasion des Tumors vor dem wirtseigenen Immunsystem zu inhibieren versucht, um dadurch die Tumorprogression zu verhindern. Als ein Mechanismus bei der Tumorevasion wurde dabei die Ausschüttung des immunsupprimierenden Faktors Adenosin identifiziert. Es wurden jedoch auch direkte protumerogene Effekte von Adenosin auf Tumorzellen bestimmter Entitäten beobachtet. Welche Rolle Adenosin bei HNSCC-Zellen spielt, ist jedoch noch ungeklärt. Daher befasste sich die vorliegende Arbeit mit der Charakterisierung des adenosinergen Systems in zwölf Zelllinien, die sich von HNSCCs ableiten. Bei den laborexperimentellen Arbeiten kamen Expressionsanalysen mit Hilfe von Polymerasekettenreaktionen, Durchflusszytometrie und Western Blots sowie funktionelle Zellassays zur Untersuchung von Proliferation, Migration und spontaner VEGF-Sekretion (engl. vascular endothelial growth factor) zur Anwendung. Das adenosinerge System besteht u.a. aus den Ektonukleotidasen CD39 und CD73 (engl. cluster of differentiation), welche im extrazellulären Raum ATP (Adenosintriphosphat) zu AMP (Adenosinmonophosphat) und schlussendlich zu Adenosin degradieren. Weiterhin spielen die vier Adenosinrezeptoren ADORA1, ADORA2A, ADORA2B und ADORA3 eine Rolle. In den untersuchten zwölf HNSCC-Zelllinien zeigte sich, dass alle CD73 auf ihrer Zelloberfläche überexprimierten, während eine Expression von CD39 nicht nachzuweisen war. Es wurde diskutiert, dass dadurch die klassische Achse der Adenosingenerierung durch die Tumorzellen alleine nicht bedient werden kann, allerdings gibt es Möglichkeiten über andere enzymatische Pfade oder diskontinuierliche Pfade unter Zuhilfenahme anderer Zellen innerhalb des Tumormikromilieus signifikante extrazelluläre Adenosinkonzentrationen trotz CD39-Defizienz zu erreichen. Weiterhin wurde ein tumorfördernder Effekt von CD73 unabhängig von seiner enzymatischen Aktivität für andere Tumorentitäten beschrieben, was prinzipiell auch bei HNSCCs der Fall sein könnte. Im Weiteren wurde gezeigt, dass von allen Adenosinrezeptor-Subtypen ausschließlich ADORA2B exprimiert wird. Dabei zeigte sich auf RNA- (engl. ribonucleic acid) als auch auf Proteinebene eine Überexpression für alle zwölf untersuchten Zelllinien, wobei die Transkriptions- und die Translationsraten miteinander korrelierten. In den folgenden Experimenten wurden die Proliferation, Migration und spontane VEGF-Sekretion unter ADORA2B-Modulation analysiert. Dabei kamen der endogene Agonist Adenosin, der im Vergleich chemisch stabilere Agonist NECA sowie der inverse Agonist PSB603 zum Einsatz. Hierbei zeigte sich, dass die Agonisten nur einen geringen positiven bis keinen Effekt auf die oben genannten untersuchten Eigenschaften hatten, während der inverse Agonist PSB603 eine signifikante Inhibition dieser Prozesse nach sich zog. Es wurde diskutiert, dass ein solcher Effekt durch eine möglicherweise vorliegende konstitutive Aktivität von ADORA2B zu erklären sei, welche bereits bei Karzinomen der Mundhöhle beschrieben wurde. Weiterhin wurde darauf hingewiesen, dass die hier dargestellten Ergebnisse in Folgestudien bereits weiter charakterisiert wurden und sich unter anderem in in vivo-Untersuchungen in Tumor-Xenograft-Modellen in Hühnereiern bestätigten. Zusammenfassend konnte die vorliegende Arbeit zeigen, dass HNSCC-Zelllinien bestimmte ‚key players‘ des adenosinergen Systems exprimieren und diese Einfluss auf die Tumorprogression haben. Insbesondere die Inhibition von ADORA2B konnte als ein potentielles vielversprechendes strategisches Angriffsziel zur Tumorsuppression herausgearbeitet werden. Daher scheint ein weiteres Forschungsbemühen zu dem adenosinergen System bei HNSCCs lohnenswert, da sich hieraus innovative Impulse zur Entwicklung spezifischer Therapien für Plattenepithelkarzinome des Kopf-Hals-Bereiches zukünftig ergeben könnten

Advances and Innovations in Ablative Head and Neck Oncologic Surgery Using Mixed Reality Technologies in Personalized Medicine

The benefit of computer-assisted planning in head and neck ablative and reconstructive surgery has been extensively documented over the last decade. This approach has been proven to offer a more secure surgical procedure. In the treatment of cancer of the head and neck, computer-assisted surgery can be used to visualize and estimate the location and extent of the tumor mass. Nowadays, some software tools even allow the visualization of the structures of interest in a mixed reality environment. However, the precise integration of mixed reality systems into a daily clinical routine is still a challenge. To date, this technology is not yet fully integrated into clinical settings such as the tumor board, surgical planning for head and neck tumors, or medical and surgical education. As a consequence, the handling of these systems is still of an experimental nature, and decision-making based on the presented data is not yet widely used. The aim of this paper is to present a novel, user-friendly 3D planning and mixed reality software and its potential application for ablative and reconstructive head and neck surgery

Prospective Evaluation of Two Wall Orbital Fractures Involving the Medial Orbital Wall: PSI Reconstruction versus PDS Repair—Worth the Effort?

Proper treatment of the two-wall fractured orbit is still controversial. Specifically, there is no consensus on the issue of the necessity of medial orbital wall repair. With anatomically critical structures at risk during the surgical approach, surgeons’ view on the necessity of medial orbital wall repair often is restricted and an aesthetically disturbing enophthalmos is more likely to be accepted. Therefore, treatment options range from leaving the medial wall without repair to reconstruction with autogenous tissue or alloplastic materials, which can lead to moderate to severe side effects. However, emerging technologies such as patient-specific implants (PSI) offer a reliable and anatomically correct reconstruction of the bony orbit. This study aimed to evaluate the outcome of full orbital reconstruction using PSIs compared to only orbital floor repair using PDS (bioresorbable polydioxanone) foils leaving the medial orbital wall untouched in traumatic two-wall orbital fractures. Of all patients treated at the University Hospital of Düsseldorf between 2017 and 2019 who suffered from traumatic orbital fracture, only patients with a two-wall orbital fracture involving both the orbital floor and the medial wall (n = 68) were included. Patients were treated either with a PSI (n = 35) or a PDS foil (n = 33). Primary outcome parameters were ophthalmological disturbances analyzed via clinical investigation and intra-orbital angles, volumes and implant position analyzed with radiological 3D-datasets. While a two-wall reconstruction using PSIs led to a significant improvement of the enophthalmos, the rate of postoperative enophthalmos was significantly increased in cases of only orbital floor repair with PDS foils. Radiologically, a significant reconstruction of the three-dimensional bony orbit succeeded with the simple use of PSIs leading to a significant reduction in the traumatically enlarged orbital volume. PSI also led to a significant reduction in the traumatically enlarged medial angle of the orbit. This was not the case for single-floor repair with PDS foil. The results of this study suggest that complex orbital fractures can be reconstructed at an even higher degree of accuracy with selective laser-melted PSIs than PDS foils. In order to achieve a true to original reconstruction of the bony orbit, surgical treatment of the medial orbital wall can be advocated for in the long term depending on the indication

Plasma Electrolytic Polished Patient-Specific Orbital Implants in Clinical Use—A Technical Note

This technical note describes the technique of plasma electrolytic polishing on orbital patient-specific implants and demonstrates clinical handling and use by the insertion of a plasma electrolytic polished orbital implant into a patient

Evaluation of the Fitting Accuracy of CAD/CAM-Manufactured Patient-Specific Implants for the Reconstruction of Cranial Defects—A Retrospective Study

Cranioplasties show overall high complication rates of up to 45.3%. Risk factors potentially associated with the occurrence of postoperative complications are frequently discussed in existing research. The present study examines the positioning of 39 patient-specific implants (PSI) made from polyetheretherketone (PEEK) and retrospectively investigates the relationship between the fitting accuracy and incidence of postoperative complications. To analyze the fitting accuracy of the implants pre- and post-operatively, STL files were created and superimposed in a 3D coordinate system, and the deviations were graphically displayed and evaluated along with the postoperative complications. On average, 95.17% (SD = 9.42) of the measurements between planned and surgically achieved implant position were within the defined tolerance range. In cases with lower accordance, an increased occurrence of complications could not be demonstrated. The overall postoperative complication rate was 64.1%. The fitting of the PEEK-PSI was highly satisfactory. There were predominantly minor deviations of the achieved compared to the planned implant positions; however, estimations were within the defined tolerance range. Despite the overall high accuracy of fitting, a considerable complication rate was found. To optimize the surgical outcome, the focus should instead be directed towards the investigation of other risk factors

Primary Orbital Reconstruction with Selective Laser Melting (SLM) of Patient-Specific Implants (PSIs): An Overview of 96 Surgically Treated Patients

Contemporary advances in technology have allowed the transfer of knowledge from industrial laser melting systems to surgery; such an approach could increase the degree of accuracy in orbital restoration. The aim of this study was to examine the accuracy of selective laser melted PSIs (patient-specific implants) and navigation in primary orbital reconstruction. Ninety-six patients with orbital fractures were included in this study. Planned vs. achieved orbital volumes (a) and angles (b) were compared to the unaffected side (n = 96). The analysis included the overlay of post-treatment on planned images (iPlan 3.0.5, Brainlab®, Feldkirchen, Germany). The mean difference in orbital volume between the digitally planned orbit and the postoperative orbit was 29.16 cm3 (SD 3.54, presurgical) to 28.33 cm3 (SD 3.64, postsurgical, t = 5.00, df = 95.00; p < 0.001), resulting in a mean volume difference (planned vs. postop) of less than 1 cm3. A 3D analysis of the color mapping showed minor deviations compared to the mirrored unaffected side. The results suggested that primary reconstruction in complex orbital wall fractures can be routinely achieved with a high degree of accuracy by using selective laser melted orbital PSIs

Simultaneous PSI-Based Orthognathic and PEEK Bone Augmentation Surgery Leads to Improved Symmetric Facial Appearance in Craniofacial Malformations

(1) The aim of the present study was to compare the outcome of facial symmetry after simultaneous digitally planned patient-specific implant (PSI-) based orthognathic surgery and polyether ether ketone (PEEK) bone augmentation in patients with craniofacial malformations. (2) To evaluate the outcome of the two different surgical approaches (conventional PSI-based orthognathic surgery versus simultaneous PSI-based orthognathic surgery with PEEK bone augmentation), a comparison of five different groups with a combination of the parameters (A) with vs. without laterognathia, (B) syndromic vs. non-syndromic, and (C) surgery with vs. without PEEK bone augmentation was conducted. The digital workflow comprised cone beam CT (CBCT) scans and virtual surgery planning for all patients in order to produce patient specific cutting guides and osteosynthesis plates. Additionally, deformed skulls were superimposed by a non-deformed skull and/or the healthy side was mirrored to produce PSI PEEK implants for augmentation. Retrospective analyses included posterior–anterior conventional radiographs as well as en face photographs taken before and nine months after surgery. (3) Simultaneous orthognathic surgery with PEEK bone augmentation significantly improves facial symmetry compared to conventional orthognathic surgery (6.5%P (3.2–9.8%P) (p = 0.001). (4) PSI-based orthognathic surgery led to improved horizontal bone alignment in all patients. Simultaneous PEEK bone augmentation enhanced facial symmetry even in patients with syndrome-related underdevelopment of both soft and hard tissues