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Disclosing the CXCR4 expression in lymphoproliferative diseases by targeted molecular imaging
(2015)
Chemokine ligand-receptor interactions play a pivotal role in cell attraction and cellular trafficking, both in normal tissue homeostasis and in disease. In cancer, chemokine receptor-4 (CXCR4) expression is an adverse prognostic factor. Early clinical studies suggest that targeting CXCR4 with suitable high-affinity antagonists might be a novel means for therapy. In addition to the preclinical evaluation of [\(^{68}\)Ga]Pentixafor in mice bearing human lymphoma xenografts as an exemplary CXCR4-expressing tumor entity, we report on the first clinical applications of [\(^{68}\)Ga]Pentixafor-Positron Emission Tomography as a powerful method for CXCR4 imaging in cancer patients. [\(^{68}\)Ga]Pentixafor binds with high affinity and selectivity to human CXCR4 and exhibits a favorable dosimetry. [\(^{68}\)Ga]Pentixafor-PET provides images with excellent specificity and contrast. This non-invasive imaging technology for quantitative assessment of CXCR4 expression allows to further elucidate the role of CXCR4/CXCL12 ligand interaction in the pathogenesis and treatment of cancer, cardiovascular diseases and autoimmune and inflammatory disorders.
Die Versorgung von Leistenhernien mit offenen und minimal-invasiven Verfahren hat in den vergangenen 30 Jahren einen vom Ergebnis her gesehen hohen Standard erreicht. Allerdings besteht noch Bedarf an einer weiteren Reduktion der postoperativen Serome, chronischen Schmerzen und des Rezidivs. In diesem Videobeitrag wird die endoskopische Anatomie der Leiste im Hinblick auf die robotische transabdominelle präperitoneale Patchplastik (r‑TAPP) dargestellt und die Operationsschritte der r‑TAPP als Video illustriert. Es werden die Ergebnisse einer Kohortenstudie an 302 konsekutiven Hernien, die mittels r‑TAPP operiert wurden, vorgestellt und hinsichtlich des Mehrwerts der robotischen Technik – auch in der Weiterbildung – diskutiert. Die r‑TAPP ist die natürliche Weiterentwicklung der konventionellen TAPP und hat das Potenzial, bei zunehmender Geräteverfügbarkeit und Reduktion der Materialkosten zu einem neuen Standard zu werden. Künftige Studien werden den vielseitigen Mehrwert der r‑TAPP auch mit neuen Parametern verfeinern müssen.
The treatment of inguinal hernias with open and minimally invasive procedures has reached a high standard in terms of outcome over the past 30 years. However, there is still need for further improvement, mainly in terms of reduction of postoperative seroma, chronic pain, and recurrence. This video article presents the endoscopic anatomy of the groin with regard to robotic transabdominal preperitoneal patch plasty (r‑TAPP) and illustrates the surgical steps of r‑TAPP with respective video sequences. The results of a cohort study of 302 consecutive hernias operated by r‑TAPP are presented and discussed in light of the added value of the robotic technique, including advantages for surgical training. r‑TAPP is the natural evolution of conventional TAPP and has the potential to become a new standard as equipment availability increases and material costs decrease. Future studies will also have to refine the multifaceted added value of r‑TAPP with new parameters.
CXCR4 is a G-protein-coupled receptor that mediates recruitment of blood cells toward its ligand SDF-1. In cancer, high CXCR4 expression is frequently associated with tumor dissemination andpoor prognosis. We evaluated the novel CXCR4 probe [\(^{68}\)Ga]Pentixafor for invivo mapping of CXCR4 expression density in mice xenografted with human CXCR4-positive MM cell lines and patients with advanced MM by means of positron emission tomography (PET). [\(^{68}\)Ga]Pentixafor PET provided images with excellent specificity and contrast. In 10 of 14 patients with advanced MM [\(^{68}\)Ga]Pentixafor PET/CT scans revealed MM manifestations, whereas only nine of 14 standard [\(^{18}\)F]fluorodeoxyglucose PET/CT scans were rated visually positive. Assessment of blood counts and standard CD34\(^{+}\) flow cytometry did not reveal significant blood count changes associated with tracer application. Based on these highly encouraging data on clinical PET imaging of CXCR4 expression in a cohort of MM patients, we conclude that [\(^{68}\)Ga]Pentixafor PET opens a broad field for clinical investigations on CXCR4 expression and for CXCR4-directed therapeutic approaches in MM and other diseases.
Draft genome of the \(Arabidopsis\) \(thaliana\) phyllosphere bacterium, \(Williamsia\) sp. ARP1
(2016)
The Gram-positive actinomycete \(Williamsia\) sp. ARP1 was originally isolated from the \(Arabidopsis\) \(thaliana\) phyllosphere. Here we describe the general physiological features of this microorganism together with the draft genome sequence and annotation. The 4,745,080 bp long genome contains 4434 protein-coding genes and 70 RNA genes. To our knowledge, this is only the second reported genome from the genus \(Williamsia\) and the first sequenced strain from the phyllosphere. The presented genomic information is interpreted in the context of an adaptation to the phyllosphere habitat.
Despite improved survival in the Rituximab (R) era, a considerable number of patients with diffuse large B-cell lymphoma (DLBCL) ultimately die from the disease. Functional imaging using [18F]fluorodeoxyglucose-PET is suggested for assessment of residual viable tumor very early during treatment but is compromised by non-specific tracer retention in inflammatory lesions. The PET tracer [18F]fluorodeoxythymidine (FLT) as surrogate marker of tumor proliferation may overcome this limitation. We present results of a prospective clinical study testing FLT-PET as superior and early predictor of response to chemotherapy and outcome in DLBCL. 54 patients underwent FLT-PET prior to and one week after the start of R-CHOP chemotherapy. Repetitive FLT-PET imaging was readily implemented into the diagnostic work-up. Our data demonstrate that the reduction of FLT standard uptake valuemean (SUVmean) and SUVmax one week after chemotherapy was significantly higher in patients achieving complete response (CR, n=48; non-CR, n=6; p<0.006). Martingale-residual and Cox proportional hazard analyses showed a significant monotonous decrease of mortality risk with increasing change in SUV. Consistent with these results, early FLT-PET response showed relevant discriminative ability in predicting CR. In conclusion, very early FLT-PET in the course of R-CHOP chemotherapy is feasible and enables identification of patients at risk for treatment failure.
Anaplastic large cell lymphoma (ALCL) is a common subtype of the heterogeneous group of peripheral T-cell lymphomas, which is characterized by large pleomorphic cells with strong expression of CD30. Translocations involving ALK, the anaplastic lymphoma kinase gene, are associated with a favorable clinical outcome. Such ALK-positive ALCLs are usually responsive to a multidrug chemotherapy with CHOP (cyclophosphamide, doxorubicin, vincristine, prednisone). However, there is no general consensus on the optimal therapy for relapsed or refractory ALCL. We report the case of a 24-year-old male suffering from ALK-positive ALCL with an uncommon manifestation of only extranodal disease in the gastric cardia region that showed primary refractoriness to standard CHOP chemotherapy. A combination therapy consisting of the anti-CD30 drug conjugate, brentuximab vedotin, and classical lymphoma salvage regimen DHAP (cisplatin, high-dose cytarabine and dexamethasone) was administered. Following two treatment cycles in 21-day intervals, the lymphoma showed considerable regression based on imaging diagnostics and no evidence of vital lymphoma in a subsequent biopsy. We did not observe any increase in toxicity; in particular, polyneuropathy and febrile neutropenia were not observed. In summary, we report that the antibody-drug conjugate brentuximab vedotin and a classical regimen used for aggressive lymphoma, DHAP, could be combined as salvage therapy in a case of refractory ALK-positive ALCL. Phase I/II studies will be required for safety and efficacy analysis.
Background: Dual phosphatidylinositol-3-kinase (PI3K)/mammalian target of rapamycin (mTOR) inhibition offers an attractive therapeutic strategy in anaplastic large cell lymphoma depending on oncogenic nucleophosmin-anaplastic lymphoma kinase (NPM-ALK) signaling. We tested the efficacy of a novel dual PI3K/mTOR inhibitor, NVP-BGT226 (BGT226), in two anaplastic large cell lymphoma cell lines in vitro and in vivo and performed an early response evaluation with positron emission tomography (PET) imaging using the standard tracer, 2-deoxy-2-[F-18] fluoro-D-glucose (FDG) and the thymidine analog, 3'-deoxy-3'-[F-18] fluorothymidine (FLT).
Methods: The biological effects of BGT226 were determined in vitro in the NPM-ALK positive cell lines SU-DHL-1 and Karpas299 by 3-[4,5-Dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide assay, propidium iodide staining, and biochemical analysis of PI3K and mTOR downstream signaling. FDG-PET and FLT-PET were performed in immunodeficient mice bearing either SU-DHL-1 or Karpas299 xenografts at baseline and 7 days after initiation of treatment with BGT226. Lymphomas were removed for immunohistochemical analysis of proliferation and apoptosis to correlate PET findings with in vivo treatment effects.
Results: SU-DHL-1 cells showed sensitivity to BGT226 in vitro, with cell cycle arrest in G0/G1 phase and an IC50 in the low nanomolar range, in contrast with Karpas299 cells, which were mainly resistant to BGT226. In vivo, both FDG-PET and FLT-PET discriminated sensitive from resistant lymphoma, as indicated by a significant reduction of tumor-to-background ratios on day 7 in treated SU-DHL-1 lymphoma-bearing animals compared with the control group, but not in animals with Karpas299 xenografts. Imaging results correlated with a marked decrease in the proliferation marker Ki67, and a slight increase in the apoptotic marker, cleaved caspase 3, as revealed by immunostaining of explanted lymphoma tissue.
Conclusion: Dual PI3K/mTOR inhibition using BGT226 is effective in ALK-positive anaplastic large cell lymphoma and can be monitored with both FDG-PET and FLT-PET early on in the course of therapy.
Cancer pathogenesis involves tumor-intrinsic genomic aberrations and tumor-cell extrinsic mechanisms such as failure of immunosurveillance and structural and functional changes in the microenvironment. Using Myc as a model oncogene we established a conditional mouse bone marrow transduction/transplantation model where the conditional activation of the oncoprotein Myc expressed in the hematopoietic system could be assessed for influencing the host microenvironment. Constitutive ectopic expression of Myc resulted in rapid onset of a lethal myeloproliferative disorder with a median survival of 21 days. In contrast, brief 4-day Myc activation by means of the estrogen receptor (ER) agonist tamoxifen did not result in gross changes in the percentage/frequency of hematopoietic lineages or hematopoietic stem/progenitor cell (HSPC) subsets, nor did Myc activation significantly change the composition of the non-hematopoietic microenvironment defined by phenotyping for CD31, ALCAM, and Sca-1 expression. Transcriptome analysis of endothelial CD45-Ter119-cells from tamoxifen-treated MycER bone marrow graft recipients revealed a gene expression signature characterized by specific changes in the Rho subfamily pathway members, in the transcription-translation-machinery and in angiogenesis. In conclusion, intra-hematopoietic Myc activation results in significant transcriptome alterations that can be attributed to oncogene-induced signals from hematopoietic cells towards the microenvironment, e. g. endothelial cells, supporting the idea that even pre-leukemic HSPC highjack components of the niche which then could protect and support the cancer-initiating population.
The mitotic spindle assembly checkpoint (SAC) maintains genome stability and marks an important target for antineoplastic therapies. However, it has remained unclear how cells execute cell fate decisions under conditions of SAC‐induced mitotic arrest. Here, we identify USP9X as the mitotic deubiquitinase of the X‐linked inhibitor of apoptosis protein (XIAP) and demonstrate that deubiquitylation and stabilization of XIAP by USP9X lead to increased resistance toward mitotic spindle poisons. We find that primary human aggressive B‐cell lymphoma samples exhibit high USP9X expression that correlate with XIAP overexpression. We show that high USP9X/XIAP expression is associated with shorter event‐free survival in patients treated with spindle poison‐containing chemotherapy. Accordingly, aggressive B‐cell lymphoma lines with USP9X and associated XIAP overexpression exhibit increased chemoresistance, reversed by specific inhibition of either USP9X or XIAP. Moreover, knockdown of USP9X or XIAP significantly delays lymphoma development and increases sensitivity to spindle poisons in a murine Eμ‐Myc lymphoma model. Together, we specify the USP9X–XIAP axis as a regulator of the mitotic cell fate decision and propose that USP9X and XIAP are potential prognostic biomarkers and therapeutic targets in aggressive B‐cell lymphoma.
Das Prinzip der gezielten Trennung bzw. Schwächung einzelner Komponenten der Bauchdecke zur Spannungsentlastung der Medianlinie bei großen abdominellen Rekonstruktionen ist seit über 30 Jahren als anteriore Komponentenseparation (aKS) bekannt und ein etabliertes Verfahren. Auf der Suche nach Alternativen mit geringerer Komplikationsrate wurde die posteriore Komponentenseparation (pKS) entwickelt; der „transversus abdominis release“ (TAR) ist eine nervenschonende Modifikation der pKS. Mit den ergonomischen Ressourcen der Robotik (z. B. abgewinkelte Instrumente) kann der TAR minimal-invasiv durchgeführt werden (r-TAR): Bruchlücken von bis zu 14 cm lassen sich verschließen und ein großes extraperitoneales Netz implantieren. In diesem Videobeitrag wird die Versorgung großer Inzisionalhernien in der r‑TAR-Technik präsentiert. Exemplarisch werden die Ergebnisse einer Kohortenstudie an 13 konsekutiven Patienten vorgestellt. Der Eingriff ist anspruchsvoll, die eigenen Ergebnisse sind – wie auch die Berichte aus der Literatur – ermutigend. Der r‑TAR entwickelt sich zur Königsdisziplin der Bauchdeckenrekonstruktion.
The principle of targeted separation or weakening of individual components of the abdominal wall to relieve tension in the median line during major abdominal reconstruction has been known for over 30 years as anterior component separation (aCS) and is an established procedure. In search of alternatives with lower complication rates, posterior component separation (pCS) was developed; transversus abdominis release (TAR) is a nerve-sparing modification of pCS. With the ergonomic resources of robotics (e.g., angled instruments), TAR can be performed in a minimally invasive manner (r-TAR): hernia gaps of up to 14 cm can be closed and a large extraperitoneal mesh implanted. In this video article, the treatment of large incisional hernias using the r‑TAR technique is presented. Exemplary results of a cohort study in 13 consecutive patients are presented. The procedure is challenging, but our own results—as well as reports from the literature—are encouraging. The r‑TAR is becoming the pinnacle procedure for abdominal wall reconstruction.
Die chirurgische Behandlung parastomaler Hernien gilt als komplex und ist bekanntermaßen komplikationsträchtig. In der Vergangenheit wurden diese Hernien durch die Relokation des Stomas oder Nahtverfahren der Austrittstelle versorgt. In den letzten Jahren wurden verschiedene netzbasierte Techniken vorgeschlagen, die heute in der minimal-invasiven Chirurgie eingesetzt werden. Mit der Verbreitung der roboterassistierten Hernienchirurgie wurden die Netzverfahren weiterentwickelt und die Ergebnisse für die Patienten erheblich verbessert. In diesem Beitrag wird ein Überblick über die verfügbaren Techniken der roboterassistierten Versorgung parastomaler Hernien präsentiert. Es werden technische Überlegungen und erste Ergebnisse des roboterassistierten modifizierten Sugarbaker-Verfahrens, der roboterassistierten Pauli-Technik und der Verwendung des trichterförmigen Netzes IPST vorgestellt. Darüber hinaus werden die Herausforderungen bei der roboterassistierten Versorgung parastomaler Hernien am Ileum-Conduit diskutiert. Die Operationstechniken werden durch Foto- und Videomaterial veranschaulicht.
The surgical treatment of parastomal hernias is considered complex and is known to be prone to complications. Traditionally, this condition was treated using relocation techniques or local suture repairs. Since then, several mesh-based techniques have been proposed and are nowadays used in minimally invasive surgery. Since the introduction of robot-assisted surgery to the field of abdominal wall surgery, several adaptations to these techniques have been made, which may significantly improve patient outcomes. In this contribution, we provide an overview of available techniques in robot-assisted parastomal hernia repair. Technical considerations and preliminary results of robot-assisted modified Sugarbaker repair, robot-assisted Pauli technique, and minimally invasive use of a funnel-shaped mesh in the treatment of parastomal hernias are presented. Furthermore, challenges in robot-assisted ileal conduit parastomal hernia repair are discussed. These techniques are illustrated by photographic and video material. Besides providing a comprehensive overview of robot-assisted parastomal hernia repair, this article focuses on the specific advantages of robot-assisted techniques in the treatment of this condition.
Die endoskopische Versorgung von Umbilikal- und Inzisionalhernien hat sich in den vergangenen 30 Jahren an die Limitationen der konventionellen laparoskopischen Instrumente angepasst. Dazu gehört die Entwicklung von Netzen für die intraperitoneale Lage (intraperitoneales Onlay-Mesh, IPOM) mit antiadhäsiven Beschichtungen; allerdings kommt es bei einem beträchtlichen Teil dieser Patienten doch zu Adhäsionen. Minimal-invasive Verfahren führen zu weniger perioperativen Komplikationen, bei einer etwas höheren Rezidivrate. Mit den ergonomischen Ressourcen der Robotik, die abgewinkelte Instrumente anbietet, besteht erstmals die Möglichkeit, Netze minimal-invasiv in unterschiedliche Bauchdeckenschichten zu implantieren und gleichzeitig eine morphologische und funktionelle Rekonstruktion der Bauchdecke zu erreichen. In diesem Videobeitrag wird die Versorgung von Ventral- und Inzisionalhernien mit Netzimplantation in den präperitonealen Raum (robotische ventrale transabdominelle präperitoneale Patchplastik, rv-TAPP) sowie in den retrorektalen Raum (r-Rives bzw. robotische transabdominelle retromuskuläre umbilikale Patchplastik [r-TARUP]) präsentiert. Es werden die Ergebnisse einer Kohortenstudie an 118 konsekutiven Patienten vorgestellt und im Hinblick auf den Mehrwert der robotischen Technik in der Extraperitonealisierung der Netze und in der Weiterbildung diskutiert.
Endoscopic management of umbilical and incisional hernias has adapted to the limitations of conventional laparoscopic instruments over the past 30 years. This includes the development of meshes for intraperitoneal placement (intraperitoneal onlay mesh, IPOM), with antiadhesive coatings; however, adhesions do occur in a significant proportion of these patients. Minimally invasive procedures result in fewer perioperative complications, but with a slightly higher recurrence rate. With the ergonomic resources of robotics, which offers angled instruments, it is now possible to implant meshes in a minimally invasively manner in different abdominal wall layers while achieving morphologic and functional reconstruction of the abdominal wall. This video article presents the treatment of ventral and incisional hernias with mesh implantation into the preperitoneal space (robot-assisted transabdominal preperitoneal ventral hernia repair, r‑ventral TAPP) as well as into the retrorectus space (r-Rives and robotic transabdominal retromuscular umbilical prosthetic repair, r‑TARUP, respectively). The results of a cohort study of 118 consecutive patients are presented and discussed with regard to the added value of the robotic technique in extraperitoneal mesh implantation and in the training of residents.