Wolfgang Krupp

Bortezomib Sensitizes Primary Human Astrocytoma Cells of WHO Grades I to IV for Tumor Necrosis Factor–Related Apoptosis-Inducing Ligand–Induced Apoptosis

Purpose: Malignant gliomas are the most aggressive human brain tumors without any curative treatment. The antitumor effect of tumor necrosis factor–related apoptosis-inducing ligand (TRAIL) in gliomas has thus far only been thoroughly established in tumor cell lines. In the present study, we investigated the therapeutic potential of TRAIL in primary human glioma cells. Experimental Design: We isolated primary tumor cells from 13 astrocytoma and oligoastrocytoma patients of all four WHO grades of malignancy and compared the levels of TRAIL-induced apoptosis induction, long-term tumor cell survival, caspase, and caspase target cleavage. Results: We established a stable culture model for isolated primary human glioma cells. In contrast to cell lines, isolated primary tumor cells from all investigated glioma patients were highly TRAIL resistant. Regardless of the tumor heterogeneity, cotreatment with the proteasome inhibitor bortezomib efficiently sensitized all primary glioma samples for TRAIL-induced apoptosis and tremendously reduced their clonogenic survival. Due to the pleiotropic effect of bortezomibenhanced TRAIL DISC formation upon TRAIL triggering, down-regulation of cFLIPL and activation of the intrinsic apoptosis pathway seem to cooperatively contribute to the antitumor effect of bortezomib/TRAIL cotreatment. Conclusion: TRAIL sensitivity of tumor cell lines is not a reliable predictor for the behavior of primary tumor cells. The widespread TRAIL resistance in primary glioma cells described here questions the therapeutic clinical benefit of TRAIL as a monotherapeutic agent. Overcoming TRAIL resistance by bortezomib cotreatment might, however, provide a powerful therapeutic option for glioma patients.

Comparative genomic hybridization in glioma: a meta-analysis of 509 cases

Much data about genetic imbalances in tumors have been accumulated by comparative genomic hybridization (CGH). In order to distinguish between significantly and coincidentally involved regions in glioma by means of a meta-analysis, we summarized and analyzed the CGH results of 509 cases published in 26 reports between 1992 and 2001. The expansion of all aberrations to the 850-band level impressively visualized distinct patterns in astrocytoma, oligodendroglioma, and ependymoma as well as loci of frequent aberrations. For example, in astrocytoma the frequency of gains culminated at 7p12, 8q24.1, and 12q13-q15 (the loci of EGF-R, C-MYC and CDK4, respectively) and losses at 9p21 (the locus of p15 and p16) and 10q23.3 where PTEN resides. Most chromosomes were variably prone to copy number changes at different scales of aberrations. At the whole chromosome level the analysis showed +7, -10 in astrocytoma and +9, +18 in ependymoma, but +20q, -9p in astrocytoma and +1q, -22q in ependymoma at the p-q arm level. Furthermore, we could confirm the correlation between the average number of copy alterations per patient (average number of copy alterations [ANCA] index) and malignancy for astrocytoma in a refined graduation as well as for oligodendroglioma. As a new parameter, the average number of affected GTG-bands per patient (average number of affected GTG bands [ANAG] index) showed an even more striking correlation with the World Health Organization grade for gains and losses.

Cell cycle, oncogenic and tumor suppressor pathways regulate numerous long and macro non-protein-coding RNAs

BackgroundThe genome is pervasively transcribed but most transcripts do not code for proteins, constituting non-protein-coding RNAs. Despite increasing numbers of functional reports of individual long non-coding RNAs (lncRNAs), assessing the extent of functionality among the non-coding transcriptional output of mammalian cells remains intricate. In the protein-coding world, transcripts differentially expressed in the context of processes essential for the survival of multicellular organisms have been instrumental in the discovery of functionally relevant proteins and their deregulation is frequently associated with diseases. We therefore systematically identified lncRNAs expressed differentially in response to oncologically relevant processes and cell-cycle, p53 and STAT3 pathways, using tiling arrays.ResultsWe found that up to 80% of the pathway-triggered transcriptional responses are non-coding. Among these we identified very large macroRNAs with pathway-specific expression patterns and demonstrated that these are likely continuous transcripts. MacroRNAs contain elements conserved in mammals and sauropsids, which in part exhibit conserved RNA secondary structure. Comparing evolutionary rates of a macroRNA to adjacent protein-coding genes suggests a local action of the transcript. Finally, in different grades of astrocytoma, a tumor disease unrelated to the initially used cell lines, macroRNAs are differentially expressed.ConclusionsIt has been shown previously that the majority of expressed non-ribosomal transcripts are non-coding. We now conclude that differential expression triggered by signaling pathways gives rise to a similar abundance of non-coding content. It is thus unlikely that the prevalence of non-coding transcripts in the cell is a trivial consequence of leaky or random transcription events.

Bortezomib sensitizes primary human esthesioneuroblastoma cells to TRAIL-induced apoptosis

TNF-related apoptosis-inducing ligand (TRAIL), a promising novel anti-cancer cytokine of the TNF superfamily, and Bortezomib, the first-in-class clinically used proteasome inhibitor, alone or in combination have been shown to efficiently kill numerous tumor cell lines. However, data concerning primary human tumor cells are very rare. Using primary esthesioneuroblastoma cells we analyzed the anti-tumor potential and the mechanism employed by Bortezomib in combination with TRAIL for the treatment of this rare but aggressive tumor. Expression of components of the TRAIL pathway was analyzed in tumor specimens and isolated primary tumor cells at the protein level. Cells were treated with TRAIL, Bortezomib, and a combination thereof, and apoptosis induction was quantified. Clonogenicity assays were performed to elucidate the long-term effect of this treatment. Despite expressing all components of the TRAIL pathway, freshly isolated primary esthesioneuroblastoma cells were completely resistant to TRAIL-induced apoptosis. They could, however, be very efficiently sensitized by subtoxic doses of Bortezomib. The influence of Bortezomib on the TRAIL pathway was analyzed and showed upregulation of TRAIL death receptor expression, enhancement of the TRAIL death-inducing signaling complex (DISC), and downregulation of anti-apoptotic proteins of the TRAIL pathway. Of clinical relevance, TRAIL-resistant primary tumor cells could be repeatedly sensitized by Bortezomib, providing the basis for repeated clinical application schedules. This is the first report on the highly synergistic induction of apoptosis in primary esthesioneuroblastoma cells by Bortezomib and TRAIL. This combination, therefore, represents a promising novel therapeutic option for esthesioneuroblastoma.

Genome-wide genetic characterization of an atypical meningioma by single-nucleotide polymorphism array–based mapping and classical cytogenetics

Most meningiomas, accounting for about 20% of intracranial tumors, can be cured by surgical removal. Yet, 8-22% of these tumors are classified as atypical or anaplastic (WHO grade II or III, respectively) presenting with a more aggressive behavior and a high relapse rate. We analyzed genomic alterations of an atypical meningioma using high-density single nucleotide polymorphism arrays (SNP-A) karyotyping combined with GTG-banding, multicolor fluorescence in situ hybridization (M-FISH), and locus-specific FISH. In accordance to recent studies applying SNP-A karyotyping in different malignancies we found that genomic lesions are present at a higher frequency than predicted by traditional cytogenetics. Most of these aberrations have not been described before. Additionally, we unveiled loss of heterozygosity (LOH) without copy number changes on chromosome regions 1p31.1, 2p16.1, 2q23.3, 6q14.1, 6q21, 9p21.1, 10q21.1, and 14q23.3, suggesting partial uniparental disomy (UPD). UPDs are currently considered to play an important role in the initiation and progression of different malignancies. Furthermore, we detected two de novo reciprocal translocations, t(8;19)(q24;q13) and t(10;16)(q22;q12.1). While GTG-banding and M-FISH data suggested balanced translocations, SNP-A analysis clearly demonstrated imbalances in the same region.

Multiple meningioma with different grades of malignancy: case report with genetic analysis applying single-nucleotide polymorphism array and classical cytogenetics.

Multiple meningiomas with synchronous tumor lesions represent only 1-9% of all meningiomas and usually show a uniform histology. The simultaneous occurrence of different grades of malignancy in these nodules is observed in only one third of multiple meningiomas. We report a case of a sporadic multiple meningioma presenting with different histopathological grades (WHO I and II). The tumor genome of both nodules was analyzed by GTG-banding, spectral karyotyping (SKY), locus-specific FISH, and single nucleotide polymorphism array (SNP-A) karyotyping. GTG-banding and SKY revealed 25 structural and 33 numerical aberrations with a slightly increased aberration frequency in the WHO grade II nodule. We could confirm terminal deletions on chromosomes 1p [ish del(1)(p36)(p58-,pter-) 16.5% WHO grade I and 20.9% WHO grade II], partial deletions on 22q, and/or monosomy 22 (monosomy 22 14% WHO grade I and 34% WHO grade II) as the most frequent aberrations in both meningioma nodules. In the meningioma WHO grade II, in addition, a de novo paracentric inversion within chromosomal band 1p36 was detectable. Furthermore, for meningiomas de novo, dicentric chromosomes 4 could be identified in both tumor nodules. We also detected previously published segmental uniparental disomy regions 1p31.1, 6q14.1, 10q21.1, and 14q23.3 in normal control DNA of the patient and in both tumor nodules. Taken together, we describe a very rare case of multiple meningioma with overlapping but also distinct genetic aberration patterns in two nodules of different WHO grades of malignancy.

Bortezomib Sensitizes Primary Meningioma Cells to TRAIL-Induced Apoptosis by Enhancing Formation of the Death-Inducing Signaling Complex

Abstract A meningioma is the most common primary intracranial tumor in adults. Here, we investigated the therapeutic potential of the tumor necrosis factor–related apoptosis-inducing ligand (TRAIL) in 37 meningiomas. Freshly isolated primary meningioma cells were treated with TRAIL with or without different sensitizing protocols, and apoptotic cell death was then quantified. Mechanisms of TRAIL sensitization were determined by a combination of Western blotting, flow cytometry, receptor complex immunoprecipitation, and siRNA-mediated knockdown experiments. Tumor necrosis factor–related apoptosis-inducing ligand receptor expression was analyzed using immunohistochemistry and quantified by an automated software-based algorithm. Primary tumor cells from 11 (29.7%) tumor samples were sensitive to TRAIL-induced apoptosis, 12 (32.4%) were intermediate TRAIL resistant, and 14 (37.8%) were completely TRAIL resistant. We tested synergistic apoptosis-inducing cotreatment strategies and determined that only the proteasome inhibitor bortezomib potently enhanced expression of the TRAIL receptors TRAIL-R1 and/or TRAIL-R2, the formation of the TRAIL death-inducing signaling complex, and activation of caspases; this treatment resulted in sensitization of all TRAIL-resistant meningioma samples to TRAIL-induced apoptosis. Bortezomib pretreatment induced NOXA expression and downregulated c-FLIP, neither of which caused the TRAIL-sensitizing effect. Native TRAIL receptor expression could not predict primary TRAIL sensitivity. This first report on TRAIL sensitivity of primary meningioma cells demonstrates that TRAIL/bortezomib cotreatment may represent a novel therapeutic option for meningiomas.

Giant intradiploic epidermoid cyst with large osteolytic lesions of the skull: a case report

IntroductionWe report a case of tumor growth over a period of four decades, presenting with large multicentric lytic lesions of the skull and a profound mass effect, without neurological deficits. Clinical and radiological features of a patient with a giant intradiploic epidermoid and its impact on the choice of treatments are discussed.Case presentationAn 81-year-old Caucasian man, who had first noticed a painless subcutaneous swelling over the left frontal scalp about 40 years ago, presented after a short episode of dizziness, which he experienced after treatment of focal retinal detachment. Computed tomography (CT) and magnetic resonance imaging (MRI) examinations revealed an exceptionally large tumor involving major parts of the skull with extensive destruction of the bone and distinct deformation of the brain. Considering his age and the absence of neurological deficits or pain, the patient refused the option of tumor removal and cranioplasty, yet agreed to a biopsy, which confirmed the suspected diagnosis.ConclusionsThe course of the disease demonstrates that even patients with large tumors, inducing distinct pathomorphological changes, do not necessarily experience significant impairment of their quality of life without surgery. This is an impressive example of the chance to lead a long and satisfying life without specific medical treatment, avoiding the inherent risks of these procedures. Yet, there is a clear indication for surgery of intradiploic epidermoids in most cases described in the literature.

Two cases of atypical meningioma with pulmonary metastases: A comparative cytogenetic analysis of chromosomes 1p and 22 and a review of the literature

We present two cases of atypical meningioma WHO grade II with a history of multiple local recurrences and late pulmonary metastases. Comparative cytogenetic analyses on 1p and 22q confirmed clonal origin of the primary intracranial meningiomas and the pulmonary metastases in both cases. These cases illustrate the importance of close neuroradiological follow‐up to detect tumor recurrence in patients with atypical meningiomas WHO grade II even with clinically stable disease and should sensitize clinicians to late extracranial metastases of these tumors, especially to the lung. In an effort to elucidate common clinical features of metastatic meningiomas, especially to the lung, the literature was reviewed from 1995 to 2014, identifying a total of 45 published cases.

Detection of novel genomic aberrations in anaplastic astrocytomas by GTG-banding, SKY, locus-specific FISH, and high density SNP-array.

Astrocytomas represent the largest and most common subgroup of brain tumors. Anaplastic astrocytoma (WHO grade III) may arise from low-grade diffuse astrocytoma (WHO grade II) or as primary tumors without any precursor lesion. Comprehensive analyses of anaplastic astrocytomas combining both cytogenetic and molecular cytogenetic techniques are rare. Therefore, we analyzed genomic alterations of five anaplastic astrocytomas using high-density single nucleotide polymorphism arrays combined with GTG-banding and FISH-techniques. By cytogenetics, we found 169 structural chromosomal aberrations most frequently involving chromosomes 1, 2, 3, 4, 10, and 12, including two not previously described alterations, a nonreciprocal translocation t(3;11)(p12;q13), and one interstitial chromosomal deletion del(2)(q21q31). Additionally, we detected previously not documented loss of heterozygosity (LOH) without copy number changes in 4/5 anaplastic astrocytomas on chromosome regions 5q11.2, 5q22.1, 6q21, 7q21.11, 7q31.33, 8q11.22, 14q21.1, 17q21.31, and 17q22, suggesting segmental uniparental disomy (UPD), applying high-density single nucleotide polymorphism arrays. UPDs are currently considered to play an important role in the initiation and progression of different malignancies. The significance of previously not described genetic alterations in anaplastic astrocytomas presented here needs to be confirmed in a larger series.