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  • American Association for Cancer Research (AACR)  (17)
  • 1
    In: Cancer Research, American Association for Cancer Research (AACR), Vol. 72, No. 16 ( 2012-08-15), p. 4074-4084
    Kurzfassung: Conventional high-grade osteosarcoma is the most common primary bone malignancy. Although altered expression of the p53 inhibitor HDMX (Mdmx/Mdm4) is associated with cancer risk, progression, and outcome in other tumor types, little is known about its role in osteosarcoma. High expression of the Hdmx splice variant HDMX-S relative to the full-length transcript (the HDMX-S/HDMX-FL ratio) correlates with reduced HDMX protein expression, faster progression, and poorer survival in several cancers. Here, we show that the HDMX-S/HDMX-FL ratio positively correlates with less HDMX protein expression, faster metastatic progression, and a trend to worse overall survival in osteosarcomas. We found that the HDMX-S/HDMX-FL ratio associated with common somatic genetic lesions connected with p53 inhibition, such as p53 mutation and HDM2 overexpression in osteosarcoma cell lines. Interestingly, this finding was not limited to osteosarcomas as we observed similar associations in breast cancer and a variety of other cancer cell lines, as well as in tumors from patients with soft tissue sarcoma. The HDMX-S/HDMX-FL ratio better defined patients with sarcoma with worse survival rates than p53 mutational status. We propose a novel role for alternative splicing of HDMX, whereby it serves as a mechanism by which HDMX protein levels are reduced in cancer cells that have already inhibited p53 activity. Alternative splicing of HDMX could, therefore, serve as a more effective biomarker for p53 pathway attenuation in cancers than p53 gene mutation. Cancer Res; 72(16); 4074–84. ©2012 AACR.
    Materialart: Online-Ressource
    ISSN: 0008-5472 , 1538-7445
    RVK:
    RVK:
    Sprache: Englisch
    Verlag: American Association for Cancer Research (AACR)
    Publikationsdatum: 2012
    ZDB Id: 2036785-5
    ZDB Id: 1432-1
    ZDB Id: 410466-3
    Standort Signatur Einschränkungen Verfügbarkeit
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  • 2
    In: Clinical Cancer Research, American Association for Cancer Research (AACR), Vol. 15, No. 8 ( 2009-04-15), p. 2685-2694
    Kurzfassung: Purpose: Histologic grade is currently the best predictor of clinical course in chondrosarcoma patients. Grading suffers, however, from extensive interobserver variability and new objective markers are needed. Hence, we have investigated DNA copy numbers in chondrosarcomas with the purpose of identifying markers useful for prognosis and subclassification. Experimental Design: The overall pattern of genomic imbalances was assessed in a series of 67 chondrosarcomas using array comparative genomic hybridization. Statistical analyses were applied to evaluate the significance of alterations detected in subgroups based on clinical data, morphology, grade, tumor size, and karyotypic features. Also, the global gene expression profiles were obtained in a subset of the tumors. Results: Genomic imbalances, in most tumors affecting large regions of the genome, were found in 90% of the cases. Several apparently distinctive aberrations affecting conventional central and peripheral tumors, respectively, were identified. Although rare, recurrent amplifications were found at 8q24.21-q24.22 and 11q22.1-q22.3, and homozygous deletions of loci previously implicated in chondrosarcoma development affected the CDKN2A, EXT1, and EXT2 genes. The chromosomal imbalances in two distinct groups of predominantly near-haploid and near-triploid tumors, respectively, support the notion that polyploidization of an initially hyperhaploid/hypodiploid cell population is a common mechanism of chondrosarcoma progression. Increasing patient age as well as tumor grade were associated with adverse outcome, but no copy number imbalance affected metastasis development or tumor-associated death. Conclusion: Despite similarities in the overall genomic patterns, the present findings suggest that some regions are specifically altered in conventional central and peripheral tumors, respectively.
    Materialart: Online-Ressource
    ISSN: 1078-0432 , 1557-3265
    RVK:
    Sprache: Englisch
    Verlag: American Association for Cancer Research (AACR)
    Publikationsdatum: 2009
    ZDB Id: 1225457-5
    ZDB Id: 2036787-9
    Standort Signatur Einschränkungen Verfügbarkeit
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  • 3
    In: Clinical Cancer Research, American Association for Cancer Research (AACR), Vol. 17, No. 8 ( 2011-04-15), p. 2110-2119
    Kurzfassung: Purpose: High-grade osteosarcoma is a malignant primary bone tumor with a peak incidence in adolescence. Overall survival (OS) of patients with resectable metastatic disease is approximately 20%. The exact mechanisms of development of metastases in osteosarcoma remain unclear. Most studies focus on tumor cells, but it is increasingly evident that stroma plays an important role in tumorigenesis and metastasis. We investigated the development of metastasis by studying tumor cells and their stromal context. Experimental Design: To identify gene signatures playing a role in metastasis, we carried out genome-wide gene expression profiling on prechemotherapy biopsies of patients who did (n = 34) and patients who did not (n = 19) develop metastases within 5 years. Immunohistochemistry (IHC) was performed on pretreatment biopsies from 2 additional cohorts (n = 63 and n = 16) and corresponding postchemotherapy resections and metastases. Results: A total of 118/132 differentially expressed genes were upregulated in patients without metastases. Remarkably, almost half of these upregulated genes had immunological functions, particularly related to macrophages. Macrophage-associated genes were expressed by infiltrating cells and not by osteosarcoma cells. Tumor-associated macrophages (TAM) were quantified with IHC and associated with significantly better overall survival (OS) in the additional patient cohorts. Osteosarcoma samples contained both M1- (CD14/HLA-DRα positive) and M2-type TAMs (CD14/CD163 positive and association with angiogenesis). Conclusions: In contrast to most other tumor types, TAMs are associated with reduced metastasis and improved survival in high-grade osteosarcoma. This study provides a biological rationale for the adjuvant treatment of high-grade osteosarcoma patients with macrophage activating agents, such as muramyl tripeptide. Clin Cancer Res; 17(8); 2110–9. ©2011 AACR.
    Materialart: Online-Ressource
    ISSN: 1078-0432 , 1557-3265
    RVK:
    Sprache: Englisch
    Verlag: American Association for Cancer Research (AACR)
    Publikationsdatum: 2011
    ZDB Id: 1225457-5
    ZDB Id: 2036787-9
    Standort Signatur Einschränkungen Verfügbarkeit
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  • 4
    In: Cancer Research, American Association for Cancer Research (AACR), Vol. 72, No. 8_Supplement ( 2012-04-15), p. 5128-5128
    Kurzfassung: High-grade osteosarcoma is a tumor with a complex genomic profile, occurring primarily in adolescents. The extensive genomic alterations obscure the identification of genes driving tumorigenesis in osteosarcoma progenitor cells. In order to identify such driver genes, we integrated DNA copy number profiles (Affymetrix SNP 6.0) of 32 diagnostic biopsies with 84 expression profiles (Illumina Human-6 v2.0) of osteosarcoma as compared with its putative progenitor cells, i.e. mesenchymal stem cells (n=12) or osteoblasts (n=3). In addition, we performed paired analyses between copy number and expression profiles of a subset of 29 patients for which we had both DNA and mRNA profiles. Integrative analyses were performed in Nexus Copy Number Software and statistical language R. Paired analyses were performed on all probes which were significantly differentially expressed in corresponding LIMMA analyses. For both non-paired and paired analyses, copy number aberration frequency was set to & gt;35%. Non-paired integrative analyses resulted in 45 genes that were present in both analyses using different control sets, i.e. MSCs and osteoblasts. 101 genes overlapped between the two paired integrative analyses. Paired analyses detected & gt;90% of all genes found with the corresponding non-paired analyses. Remarkably, approximately twice as many genes as found in the corresponding non-paired analyses were detected. Affected genes were compared with differential expression in osteosarcoma cell lines. An overrepresentation of altered cell division related genes was found, such as MCM4 and LATS2, suggesting that deregulation of the cell cycle is an initial driver of osteosarcomagenesis. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 5128. doi:1538-7445.AM2012-5128
    Materialart: Online-Ressource
    ISSN: 0008-5472 , 1538-7445
    RVK:
    RVK:
    Sprache: Englisch
    Verlag: American Association for Cancer Research (AACR)
    Publikationsdatum: 2012
    ZDB Id: 2036785-5
    ZDB Id: 1432-1
    ZDB Id: 410466-3
    Standort Signatur Einschränkungen Verfügbarkeit
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  • 5
    Online-Ressource
    Online-Ressource
    American Association for Cancer Research (AACR) ; 2007
    In:  Clinical Cancer Research Vol. 13, No. 24 ( 2007-12-15), p. 7322-7328
    In: Clinical Cancer Research, American Association for Cancer Research (AACR), Vol. 13, No. 24 ( 2007-12-15), p. 7322-7328
    Kurzfassung: Purpose: Angiomatoid fibrous histiocytoma (AFH) is a low-grade mesenchymal neoplasm which usually occurs in children and adolescents. Either FUS-ATF1 or EWSR1-ATF1 have been detected in the few cases published, pointing to the interchangeable role of FUS and EWSR1 in this entity. EWSR1-ATF1 also represents the most frequent genetic alteration in clear cell sarcoma, suggesting the existence of a molecular homology between these two histotypes. We investigated the presence of EWSR1-CREB1, recently found in gastrointestinal clear cell sarcoma, and FUS-CREB1, as well as the already reported FUS-ATF1 and EWSR1-ATF1 in a series of AFH. Experimental Design: Fourteen cases were analyzed by fluorescence in situ hybridization (FISH) on paraffin-embedded tissue sections, using a commercial EWSR1 probe and custom-designed probes for FUS, ATF1, and CREB1. In two cases, four-color FISH was also done. Reverse transcription-PCR for the four hypothetical fusion genes was done in one case, for which frozen material was available. Results: Thirteen cases showed rearrangements of both EWSR1 and CREB1, whereas one case showed the rearrangement of both EWSR1 and ATF1. Four-color FISH confirmed the results in two selected cases. Reverse transcription-PCR showed EWSR1-CREB1 transcript in the case analyzed. Conclusion: We identified the presence of either EWSR1-CREB1 or EWSR1-ATF1 in all the cases, strengthening the concept of chromosomal promiscuity between AFH and clear cell sarcoma. Either the occurrence of a second unknown tumor-specific molecular event or, perhaps more likely, divergent differentiation programs of the putatively distinct precursor cells of AFH and clear cell sarcoma might be invoked in order to explain the two different phenotypes.
    Materialart: Online-Ressource
    ISSN: 1078-0432 , 1557-3265
    RVK:
    Sprache: Englisch
    Verlag: American Association for Cancer Research (AACR)
    Publikationsdatum: 2007
    ZDB Id: 1225457-5
    ZDB Id: 2036787-9
    Standort Signatur Einschränkungen Verfügbarkeit
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  • 6
    In: Clinical Cancer Research, American Association for Cancer Research (AACR), Vol. 15, No. 12 ( 2009-06-15), p. 4191-4198
    Kurzfassung: Purpose: Altered expression of cell cycle/apoptosis key regulators may promote tumor progression, reflect secondary genetic/epigenetic events, and impair the effectiveness of therapy. Their expression pattern might then identify gastrointestinal stromal tumor (GIST) patient subgroups with different response to imatinib and elucidate novel therapeutic targets. Experimental Design: Immunohistochemical evaluation of expression of p53, p16, p21, CHK2, CCND1, BCL2, CDK4, and MDM2 was done on 353 histologically validated GIST patients enrolled into a European/Australasian phase III trial. TP53 was screened for mutations in cases with presumptive nonfunctional protein; that is, high p53 and low expression of the two downstream molecules p21 and MDM2. Results were correlated with clinicopathologic data, KIT/PDGFRA mutation status, and imatinib dosage. Results: Frequent impaired expression was found for BCL2 (78%), CHK2 (53%), p53 (50%), and p16 (47%). Stomach-originating GISTs showed significantly lower expression of p21, p16, and BCL2. KIT/PDGFRA wild-type GISTs had significant lower expression of CDK4. Eighty-eight percent of the high p53 expressers show low downstream target activation, indicating a nonfunctional p53 route. Of these high p53 expressers, 16.4% harbor a detectable TP53 mutation. Multivariate analysis, including previously identified markers, showed an independent effect of p53 and p16 on progression-free survival (PFS). Patients with high level of CHK2 and p21 showed significantly better PFS upon a high-dose regimen. Conclusions: Impaired p53, p16, BCL2, and CHK2 expression is common in advanced GISTs. Distinct patterns of expression correlate with tumor site, genotype, and PFS. Cell cycle/apoptosis maintenance is instrumental for optimal response to imatinib.
    Materialart: Online-Ressource
    ISSN: 1078-0432 , 1557-3265
    RVK:
    Sprache: Englisch
    Verlag: American Association for Cancer Research (AACR)
    Publikationsdatum: 2009
    ZDB Id: 1225457-5
    ZDB Id: 2036787-9
    Standort Signatur Einschränkungen Verfügbarkeit
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  • 7
    In: Cancer Research, American Association for Cancer Research (AACR), Vol. 70, No. 18 ( 2010-09-15), p. 7304-7314
    Kurzfassung: Intimal sarcoma (IS) is a rare, malignant, and aggressive tumor that shows a relentless course with a concomitant low survival rate and for which no effective treatment is available. In this study, 21 cases of large arterial blood vessel IS were analyzed by immunohistochemistry and fluorescence in situ hybridization and selectively by karyotyping, array comparative genomic hybridization, sequencing, phospho-kinase antibody arrays, and Western immunoblotting in search for novel diagnostic markers and potential molecular therapeutic targets. Ex vivo immunoassays were applied to test the sensitivity of IS primary tumor cells to the receptor tyrosine kinase (RTK) inhibitors imatinib and dasatinib. We showed that amplification of platelet-derived growth factor receptor α (PDGFRA) is a common finding in IS, which should be considered as a molecular hallmark of this entity. This amplification is consistently associated with PDGFRA activation. Furthermore, the tumors reveal persistent activation of the epidermal growth factor receptor (EGFR), concurrent to PDGFRA activation. Activated PDGFRA and EGFR frequently coexist with amplification and overexpression of the MDM2 oncogene. Ex vivo immunoassays on primary IS cells from one case showed the potency of dasatinib to inhibit PDGFRA and downstream signaling pathways. Our findings provide a rationale for investigating therapies that target PDGFRA, EGFR, or MDM2 in IS. Given the clonal heterogeneity of this tumor type and the potential cross-talk between the PDGFRA and EGFR signaling pathways, targeting multiple RTKs and aberrant downstream effectors might be required to improve the therapeutic outcome for patients with this disease. Cancer Res; 70(18); 7304–14. ©2010 AACR.
    Materialart: Online-Ressource
    ISSN: 0008-5472 , 1538-7445
    RVK:
    RVK:
    Sprache: Englisch
    Verlag: American Association for Cancer Research (AACR)
    Publikationsdatum: 2010
    ZDB Id: 2036785-5
    ZDB Id: 1432-1
    ZDB Id: 410466-3
    Standort Signatur Einschränkungen Verfügbarkeit
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  • 8
    In: Clinical Cancer Research, American Association for Cancer Research (AACR), Vol. 11, No. 22 ( 2005-11-15), p. 8028-8035
    Kurzfassung: Purpose: Chondrosarcoma is a malignant cartilaginous matrix–producing tumor that can be lethal in 10% to 50% of the patients. Surgery is the only effective treatment known as these tumors are notorious refractory to all types of conventional chemotherapy or radiotherapy. To identify a target for therapy, we want to determine whether estrogen signaling is active in chondrosarcoma because estrogen is important in the regulation of longitudinal growth that is initiated by chondrocyte proliferation and differentiation in the epiphyseal growth plate of long bones. Experimental Design: We studied protein expression of the estrogen receptor in 35 cartilaginous tumors as well as mRNA levels for the estrogen receptor and for aromatase, an enzyme for estrogen synthesis and another potential therapeutic target. Furthermore, the activity of aromatase was determined in vitro by the tritiated water release assay. Dose-response experiments with chondrosarcoma cultured cells were done with estrogen, androstenedione, and exemestane. Results: All chondrosarcomas tested showed mRNA and nuclear protein expression of the estrogen receptor. Also, aromatase mRNA was detected. The aromatase activity assay showed a functional aromatase enzyme in primary chondrosarcoma cultures and in a cell line. Growth of chondrosarcoma cell cultures can be stimulated by adding estrogen or androstenedione, which can be inhibited by exemestane. Conclusions: These results show, on the RNA, protein, and cell biological levels, that the ligand and the receptor are active in estrogen-mediated signal transduction. This observation implicates potential use of targeted drugs that interfere with estrogen signaling, such as those applied for treating breast cancer.
    Materialart: Online-Ressource
    ISSN: 1078-0432 , 1557-3265
    RVK:
    Sprache: Englisch
    Verlag: American Association for Cancer Research (AACR)
    Publikationsdatum: 2005
    ZDB Id: 1225457-5
    ZDB Id: 2036787-9
    Standort Signatur Einschränkungen Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 9
    In: Clinical Cancer Research, American Association for Cancer Research (AACR), Vol. 18, No. 2 ( 2012-01-15), p. 432-441
    Kurzfassung: Purpose: Osteosarcoma and Ewing's sarcoma are the most common bone tumors in children and adolescents. Despite intensive chemotherapy, patients with advanced disease have a poor prognosis, illustrating the need for alternative therapies. Sarcoma cells are susceptible to the cytolytic activity of resting natural killer (NK) cells which can be improved by interleukin (IL)-15 stimulation. In this study, we explored whether the cytolytic function of resting NK cells can be augmented and specifically directed toward sarcoma cells by antibody-dependent cellular cytotoxicity (ADCC). Experimental Design: Epidermal growth factor receptor (EGFR) expression was examined on osteosarcoma and Ewing's sarcoma cell lines by flow cytometry and in osteosarcoma biopsy and resection specimens by immunohistochemistry. Cetuximab-mediated ADCC by NK cells from osteosarcoma patients and healthy controls was measured with 4-hour 51Cr release assays. Results: EGFR surface expression was shown on chemotherapy-sensitive and chemotherapy-resistant osteosarcoma cells (12/12), most primary osteosarcoma cultures (4/5), and few Ewing's sarcoma cell lines (2/7). In the presence of cetuximab, the cytolytic activity of resting NK cells against all EGFR-expressing sarcoma cells was substantially increased and comparable with that of IL-15–activated NK cells. Surface EGFR expression on primary osteosarcoma cultures correlated with EGFR expression in the original tumor. The cytolytic activity of osteosarcoma patient-derived NK cells against autologous tumor cells was as efficient as that of NK cells from healthy donors. Conclusion: Our data show that the cytolytic potential of resting NK cells can be potentiated and directed toward osteosarcoma cells with cetuximab. Therefore, cetuximab-mediated immunotherapy may be considered a novel treatment modality in the management of advanced osteosarcoma. Clin Cancer Res; 18(2); 432–41. ©2011 AACR.
    Materialart: Online-Ressource
    ISSN: 1078-0432 , 1557-3265
    RVK:
    Sprache: Englisch
    Verlag: American Association for Cancer Research (AACR)
    Publikationsdatum: 2012
    ZDB Id: 1225457-5
    ZDB Id: 2036787-9
    Standort Signatur Einschränkungen Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 10
    In: Clinical Cancer Research, American Association for Cancer Research (AACR), Vol. 13, No. 1 ( 2007-01-01), p. 206-214
    Kurzfassung: Purpose: Ewing sarcoma is a common pediatric bone tumor with an unfavorable prognosis for metastatic or recurrent disease. Cellular immunotherapy may provide new treatment options and depends on the cytolytic death receptor and perforin/granzyme pathways. Expression of death receptor pathway inhibitor cellular FLICE inhibitory protein (cFLIP), initiator caspase-8, and granzyme B inhibitor protease inhibitor-9 (PI-9) have been reported to determine susceptibility to cell- and chemotherapy-mediated killing in several tumor types. Here, we have studied their in vitro and in vivo expression in Ewing sarcoma and the implications for susceptibility to cytotoxicity. Experimental Design: Ewing sarcoma cell lines (n = 8) were tested for cFLIP, PI-9, and caspase-8 expression. Functional significance was tested by anti-Fas antibody (death receptor pathway) or natural killer cell (perforin/granzyme pathway) treatment. Immunohistochemistry was done on 28 sections from 18 patients. In half of the cases, sequential material, including metastases, was available. Results: Although all tested Ewing sarcoma cell lines expressed cFLIP, resistance to CD95/Fas–mediated apoptosis was only observed in two cell lines lacking caspase-8 expression. PI-9 was expressed at low levels in four of eight Ewing sarcoma cell lines, but positive cell lines remained susceptible to perforin/granzyme–mediated killing. In primary Ewing sarcoma, including metastases, cFLIP was abundantly expressed in 18 of 18 patients. Caspase-8 was expressed in all patients but showed more intertumoral and intratumoral variation in both intensity and heterogeneity of staining. PI-9, in contrast, was undetectable. Conclusions: The expression patterns of cFLIP, caspase-8, and the absence of PI-9 provide a rationale to preferentially exploit the perforin/granzyme pathway in cytotoxic therapies against Ewing sarcoma.
    Materialart: Online-Ressource
    ISSN: 1078-0432 , 1557-3265
    RVK:
    Sprache: Englisch
    Verlag: American Association for Cancer Research (AACR)
    Publikationsdatum: 2007
    ZDB Id: 1225457-5
    ZDB Id: 2036787-9
    Standort Signatur Einschränkungen Verfügbarkeit
    BibTip Andere fanden auch interessant ...
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