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  • 1
    In: Cancer Research, American Association for Cancer Research (AACR), Vol. 83, No. 7_Supplement ( 2023-04-04), p. 44-44
    Abstract: Renal cell carcinoma (RCC), is the most common kidney cancer of adults, originating in the lining of the proximal convoluted tubule. Prognosis is poor in patients with advanced or metastasized RCC. Drug resistance towards Standard of Care (SoC, incl. everolimus, sorafenib, or sunitinib) drugs develops frequently within months. Therefore, development of novel options to target acquired TKI resistance mechanisms in advanced and metastatic RCC is still an urgent medical need. Preclinical models with high translational relevance can promote the implementation of novel personalized therapies. To evaluate novel targeted therapies and their combinations in preclinical settings, patient-derived xenograft (PDX) models represent valuable tools. Responsible local ethics committees approved usage of patient tissue and all animal procedures. In this study, RCC tissue from 167 patients was collected and xenotransplanted in mice. Partially, a multi-region approach, xenografting tissue from different regions of one tumor, was used. PDX models were characterized by immunohistochemistry (Ki-67, CD31, Pax2 and Pax8 antibodies), gene expression, copy number variations and mutational analyses. To evaluate in vivo drug response of RCC PDX models, mice transplanted with PDX tumors were treated with bevacizumab (i.p.), with everolimus, sorafenib, or sunitinib (p.o.). Adopted clinical response criteria for solid tumors (RECIST) were applied to classify the anti-tumor activity of the tested compounds in RCC PDX models. Next generation sequencing (NGS, panel) and transcriptome data were used to compare primary tumors and metastases. A comprehensive panel of subcutaneous RCC PDX models with well-conserved molecular and pathological features over multiple passages was established. The overall take for the RCC PDX in this study was 21%. Tumor growth characteristics were heterogeneous throughout the different models but were stable during in vivo passaging. Drug screening towards four SoC drugs, targeting the VEGF and PI3K/mTOR pathway, revealed individual and heterogeneous response profiles in the PDX, resembling the clinical situation. Intra-tumor heterogeneity can be assessed via PDX models from multi-tumor regions from one patient in our platform. Development of corresponding in vitro cell culture models from the PDX enables advanced high throughput drug screening in a personalized context. Analyzing novel targeted molecules is possible due to the pre-established molecular characterization of the PDX at the genomic and expression level. In conclusion, we established a new and molecularly characterized panel of RCC PDX models with high relevance for translational preclinical research. Citation Format: Dennis Kobelt, Dennis Gürgen, Michael Becker, Mathias Dahlmann, Susanne Flechsig, Elke Schaeffeler, Florian A. Büttner, Christian Schmees, Regina Bohnert, Jens Bedke, Matthias Schwab, Johann J. Wendler, Martin Schostak, Burkhard Jandrig, Wolfgang Walther, Jens Hoffmann. An in vivo platform of pre-characterized renal cell carcinoma (RCC) patient-derived xenograft models allows the preclinical evaluation of patient-tailored intervention strategies [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 44.
    Type of Medium: Online Resource
    ISSN: 1538-7445
    Language: English
    Publisher: American Association for Cancer Research (AACR)
    Publication Date: 2023
    detail.hit.zdb_id: 2036785-5
    detail.hit.zdb_id: 1432-1
    detail.hit.zdb_id: 410466-3
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  • 2
    In: Journal of Experimental & Clinical Cancer Research, Springer Science and Business Media LLC, Vol. 41, No. 1 ( 2022-12)
    Abstract: An amendment to this paper has been published and can be accessed via the original article.
    Type of Medium: Online Resource
    ISSN: 1756-9966
    Language: English
    Publisher: Springer Science and Business Media LLC
    Publication Date: 2022
    detail.hit.zdb_id: 2430698-8
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  • 3
    In: American Journal of Physiology-Heart and Circulatory Physiology, American Physiological Society, Vol. 301, No. 1 ( 2011-07), p. H115-H122
    Abstract: Exercise-induced cardiac hypertrophy has been recently identified to be regulated in a sex-specific manner. In parallel, women exhibit enhanced exercise-mediated lipolysis compared with men, which might be linked to cardiac responses. The aim of the present study was to assess if previously reported sex-dependent differences in the cardiac hypertrophic response during exercise are associated with differences in cardiac energy substrate availability/utilization. Female and male C57BL/6J mice were challenged with active treadmill running for 1.5 h/day (0.25 m/s) over 4 wk. Mice underwent cardiac and metabolic phenotyping including echocardiography, small-animal PET, peri-exercise indirect calorimetry, and analysis of adipose tissue (AT) lipolysis and cardiac gene expression. Female mice exhibited increased cardiac hypertrophic responses to exercise compared with male mice, measured by echocardiography [percent increase in left ventricular mass (LVM): female: 22.2 ± 0.8%, male: 9.0 ± 0.2%; P 〈 0.05]. This was associated with increased plasma free fatty acid (FFA) levels and augmented AT lipolysis in female mice after training, whereas FFA levels from male mice decreased. The respiratory quotient during exercise was significantly lower in female mice indicative for preferential utilization of fatty acids. In parallel, myocardial glucose uptake was reduced in female mice after exercise, analyzed by PET {injection dose (ID)/LVM [%ID/g] : 36.8 ± 3.5 female sedentary vs. 28.3 ± 4.3 female training; P 〈 0.05}, whereas cardiac glucose uptake was unaltered after exercise in male counterparts. Cardiac genes involved in fatty acid uptake/oxidation in females were increased compared with male mice. Collectively, our data demonstrate that sex differences in exercise-induced cardiac hypertrophy are associated with changes in cardiac substrate availability and utilization.
    Type of Medium: Online Resource
    ISSN: 0363-6135 , 1522-1539
    RVK:
    Language: English
    Publisher: American Physiological Society
    Publication Date: 2011
    detail.hit.zdb_id: 1477308-9
    SSG: 12
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  • 4
    In: Nature Communications, Springer Science and Business Media LLC, Vol. 12, No. 1 ( 2021-11-23)
    Abstract: Intratumour heterogeneity is a major cause of treatment failure in cancer. We present in-depth analyses combining transcriptomic and genomic profiling with ultra-deep targeted sequencing of multiregional biopsies in 10 patients with neuroblastoma, a devastating childhood tumour. We observe high spatial and temporal heterogeneity in somatic mutations and somatic copy-number alterations which are reflected on the transcriptomic level. Mutations in some druggable target genes including ALK and FGFR1 are heterogeneous at diagnosis and/or relapse, raising the issue whether current target prioritization and molecular risk stratification procedures in single biopsies are sufficiently reliable for therapy decisions. The genetic heterogeneity in gene mutations and chromosome aberrations observed in deep analyses from patient courses suggest clonal evolution before treatment and under treatment pressure, and support early emergence of metastatic clones and ongoing chromosomal instability during disease evolution. We report continuous clonal evolution on mutational and copy number levels in neuroblastoma, and detail its implications for therapy selection, risk stratification and therapy resistance.
    Type of Medium: Online Resource
    ISSN: 2041-1723
    Language: English
    Publisher: Springer Science and Business Media LLC
    Publication Date: 2021
    detail.hit.zdb_id: 2553671-0
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  • 5
    In: Neuro-Oncology, Oxford University Press (OUP), Vol. 24, No. Supplement_1 ( 2022-06-03), p. i189-i189
    Abstract: Thanks to state-of-the-art molecular profiling techniques we by now have a much better understanding of pediatric cancers and what is driving them. On the other hand, we have also realized that pediatric cancers are much more heterogeneous than previously thought. Many new types and subtypes of pediatric cancers have been identified with distinct molecular and clinical characteristics. However, for many if not most of these new types and subtypes there is no specific treatment available, yet. In order to develop specific treatment protocols and to increase survival rates for pediatric cancer patients further, both at diagnosis and relapse/metastasis, we need a large collection of well-characterized preclinical models representing all the different types and subtypes. These models can be used for preclinical drug testing to prioritize the pediatric development of anticancer drugs that would be best targeting pediatric tumor biology. The ITCC-P4 consortium, which is a collaboration between many academic centers across Europe, several companies involved in in vivo preclinical testing, and ten pharmaceutical companies, started in 2017 with the overall aim to establish a sustainable platform of & gt;400 molecularly well-characterized PDX models of high-risk pediatric cancers and to use them for in vivo testing of novel mechanism-of-action based treatments. Currently, 340 models have been fully established, including 87 brain tumor models and 253 non-brain tumor models, together representing many different tumor types both from primary and relapsed/metastatic disease. Out of these 340 models, 252 have been fully molecularly characterized, most of them together with their matching original tumors, and almost of all these models are currently being subjected to in vivo testing using three standard of care drugs and six novel mechanism-of-action based drugs. In this presentation, an update on the current status of the ITCC-P4 platform and the data we collectively have generated thus far will be presented.
    Type of Medium: Online Resource
    ISSN: 1522-8517 , 1523-5866
    Language: English
    Publisher: Oxford University Press (OUP)
    Publication Date: 2022
    detail.hit.zdb_id: 2094060-9
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  • 6
    In: Scientific Reports, Springer Science and Business Media LLC, Vol. 10, No. 1 ( 2020-02-25)
    Abstract: An amendment to this paper has been published and can be accessed via a link at the top of the paper.
    Type of Medium: Online Resource
    ISSN: 2045-2322
    Language: English
    Publisher: Springer Science and Business Media LLC
    Publication Date: 2020
    detail.hit.zdb_id: 2615211-3
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  • 7
    In: Scientific Reports, Springer Science and Business Media LLC, Vol. 9, No. 1 ( 2019-12-27)
    Abstract: Vascular regeneration depends on intact function of progenitors of vascular smooth muscle cells such as pericytes and their circulating counterparts, mesenchymal stromal cells (MSC). Deregulated MSC differentiation and maladaptive cell fate programs associated with age and metabolic diseases may exacerbate arteriosclerosis due to excessive transformation to osteoblast-like calcifying cells. Targeting mTOR, a central controller of differentiation and cell fates, could offer novel therapeutic perspectives. In a cell culture model for osteoblastic differentiation of pluripotent human MSC we found distinct roles for mTORC1 and mTORC2 in the regulation of differentiation towards calcifying osteoblasts via cell fate programs in a temporally-controlled sequence. Activation of mTORC1 with induction of cellular senescence and apoptosis were hallmarks of transition to a calcifying phenotype. Inhibition of mTORC1 with Rapamycin elicited reciprocal activation of mTORC2, enhanced autophagy and recruited anti-apoptotic signals, conferring protection from calcification. Pharmacologic and genetic negative interference with mTORC2 function or autophagy both abolished regenerative programs but induced cellular senescence, apoptosis, and calcification. Overexpression of the mTORC2 constituent rictor revealed that enhanced mTORC2 signaling without altered mTORC1 function was sufficient to inhibit calcification. Studies in mice reproduced the in vitro effects of mTOR modulation with Rapamycin on cell fates in vascular cells in vivo . Amplification of mTORC2 signaling promotes protective cell fates including autophagy to counteract osteoblast differentiation and calcification of MSC, representing a novel mTORC2 function. Regenerative approaches aimed at modulating mTOR network activation patterns hold promise for delaying age-related vascular diseases and treatment of accelerated arteriosclerosis in chronic metabolic conditions.
    Type of Medium: Online Resource
    ISSN: 2045-2322
    Language: English
    Publisher: Springer Science and Business Media LLC
    Publication Date: 2019
    detail.hit.zdb_id: 2615211-3
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  • 8
    In: Acta Physiologica, Wiley, Vol. 227, No. 2 ( 2019-10)
    Abstract: Imbalances in cytochrome P450 (CYP)‐dependent eicosanoid formation may play a central role in ischemic acute kidney injury (AKI). We reported previously that inhibition of 20‐hydroxyeicosatetraenoic acid (20‐HETE) action ameliorated ischemia/reperfusion (I/R)‐induced AKI in rats. Now we tested the hypothesis that enhancement of epoxyeicosatrienoic acid (EET) actions may counteract the detrimental effects of 20‐HETE and prevent the initiation of AKI. Methods Male Lewis rats underwent right nephrectomy and ischemia was induced by 45 min clamping of the left renal pedicle followed by up to 48 h of reperfusion. Circulating CYP‐eicosanoid profiles were compared in patients who underwent cardiac surgery with (n = 21) and without (n = 38) developing postoperative AKI. Results Ischemia induced an about eightfold increase of renal 20‐HETE levels, whereas free EETs were not accumulated. To compensate for this imbalance, a synthetic 14,15‐EET analogue was administered by intrarenal infusion before ischemia. The EET analogue improved renal reoxygenation as monitored by in vivo parametric MRI during the initial 2 h reperfusion phase. The EET analogue improved PI3K‐ as well as mTORC2‐dependent rephosphorylation of Akt, induced inactivation of GSK‐3β, reduced the development of tubular apoptosis and attenuated inflammatory cell infiltration. The EET analogue also significantly alleviated the I/R‐induced drop in creatinine clearance. Patients developing postoperative AKI featured increased preoperative 20‐HETE and 8,9‐EET levels. Conclusions Pharmacological interventions targeting the CYP‐eicosanoid pathway could offer promising new options for AKI prevention. Individual differences in CYP‐eicosanoid formation may contribute to the risk of developing AKI in clinical settings.
    Type of Medium: Online Resource
    ISSN: 1748-1708 , 1748-1716
    URL: Issue
    Language: English
    Publisher: Wiley
    Publication Date: 2019
    detail.hit.zdb_id: 2617148-X
    detail.hit.zdb_id: 2219379-0
    SSG: 12
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  • 9
    In: Hypertension, Ovid Technologies (Wolters Kluwer Health), Vol. 64, No. suppl_1 ( 2014-09)
    Abstract: Mechanistic target of rapamycin (mTOR) kinase operates in two functionally and structurally distinct multiprotein complexes mTORC1 and mTORC2. mTORC1 including its defining raptor protein is a critical mediator of myocardial growth. We induced cardiomyocyte specific raptor-KO (cKO) deletion to investigate a sex specific role of mTORC1 during cardiac adaptation in normotensive DOCA-salt mice. Untypical for this mild cardiac stress model, raptor-cKO females had sharper decrease in EF (51 vs. 26%) than males (50 vs. 32%) already at 3 weeks after start of DOCA-salt challenge. Male raptor-cKO mice mounted eccentric hypertrophic response upon DOCA-salt indicated by heart weight/tibia length ratios (6.7 to 8.0) as compared to their WT litters (6.6 to 7.6). In contrast female raptor-cKO (5.8 to 6.4) minimally differed from their litters (5.8 to 6.6). Severe dilative phenotype was detected in both sexes regardless of DOCA-salt challenge. In addition, we found tremendous diffuse left ventricular fibrosis which was also more prominent in raptor-cKO females. Collagen depositions in the LV visualized by Sirius red staining increased 10fold in males (1.0 to 10.6%) and 15fold in females (0.9 to 15.7%), respectively. Expression of raptor protein in the heart was diminished by 80% in raptor cKO mice of both sexes what lead to similar extent of decreased activity of direct mTORC1 downstream targets phospho-S6 ribosomal protein and phospho-4E-BP1Ser65 (68% reduction in males vs. 61% in females. Over-compensatory mTORC2 activation in cKO animals via phospho-AKTSer473 (12fold increase) and induction of anti-apoptotic signaling was similar in both sexes. However, raptor-cKO females failed to up-regulate expression of mitochondrial genes such as Mtnd1 (ND1), mt-Co1 (COX1) and Atp5i (ATP5k), stressing sex differences in mTORC1 dependent mitochondrial adaptation. In addition, transmission electron microscopy (TEM) points towards structural alterations of mitochondrial morphology. Intact mTORC1 function is important for myocardial adaptation in both sexes. More severe phenotype in females further implicates mTORC1 to be essential for intrinsic female cardio protection.
    Type of Medium: Online Resource
    ISSN: 0194-911X , 1524-4563
    Language: English
    Publisher: Ovid Technologies (Wolters Kluwer Health)
    Publication Date: 2014
    detail.hit.zdb_id: 2094210-2
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  • 10
    In: Journal of Experimental & Clinical Cancer Research, Springer Science and Business Media LLC, Vol. 40, No. 1 ( 2021-10-15)
    Abstract: Histone acetylation and deacetylation seem processes involved in the pathogenesis of Ewing sarcoma (EwS). Here histone deacetylases (HDAC) class I were investigated. Methods Their role was determined using different inhibitors including TSA, Romidepsin, Entinostat and PCI-34051 as well as CRISPR/Cas9 class I HDAC knockouts and HDAC RNAi. To analyze resulting changes microarray analysis, qRT-PCR, western blotting, Co-IP, proliferation, apoptosis, differentiation, invasion assays and xenograft-mouse models were used. Results Class I HDACs are constitutively expressed in EwS. Patients with high levels of individual class I HDAC expression show decreased overall survival. CRISPR/Cas9 class I HDAC knockout of individual HDACs such as HDAC1 and HDAC2 inhibited invasiveness, and blocked local tumor growth in xenograft mice. Microarray analysis demonstrated that treatment with individual HDAC inhibitors (HDACi) blocked an EWS-FLI1 specific expression profile, while Entinostat in addition suppressed metastasis relevant genes. EwS cells demonstrated increased susceptibility to treatment with chemotherapeutics including Doxorubicin in the presence of HDACi. Furthermore, HDACi treatment mimicked RNAi of EZH2 in EwS. Treated cells showed diminished growth capacity, but an increased endothelial as well as neuronal differentiation ability. HDACi synergizes with EED inhibitor (EEDi) in vitro and together inhibited tumor growth in xenograft mice. Co-IP experiments identified HDAC class I family members as part of a regulatory complex together with PRC2. Conclusions Class I HDAC proteins seem to be important mediators of the pathognomonic EWS-ETS-mediated transcription program in EwS and in combination therapy, co-treatment with HDACi is an interesting new treatment opportunity for this malignant disease.
    Type of Medium: Online Resource
    ISSN: 1756-9966
    Language: English
    Publisher: Springer Science and Business Media LLC
    Publication Date: 2021
    detail.hit.zdb_id: 2430698-8
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