Sandra Boots-Sprenger

Publications (5)23.14 Total impact

• Article: Robust detection of EGFR copy number changes and EGFR variant III: technical aspects and relevance for glioma diagnostics.

  Judith Jeuken, Angelique Sijben, Cristina Alenda, Jos Rijntjes, Marieke Dekkers, Sandra Boots-Sprenger, Roger McLendon, Pieter Wesseling
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  ABSTRACT: Epidermal growth factor receptor (EGFR) is commonly affected in cancer, generally in the form of an increase in DNA copy number and/or as mutation variants [e.g., EGFR variant III (EGFRvIII), an in-frame deletion of exons 2-7]. While detection of EGFR aberrations can be expected to be relevant for glioma patients, such analysis has not yet been implemented in a routine setting, also because feasible and robust assays were lacking. We evaluated multiplex ligation-dependent probe amplification (MLPA) for detection of EGFR amplification and EGFRvIII in DNA of a spectrum of 216 diffuse gliomas. EGFRvIII detection was verified at the protein level by immunohistochemistry and at the RNA level using the conventionally used endpoint RT-PCR as well as a newly developed quantitative RT-PCR. Compared to these techniques, the DNA-based MLPA assay for EGFR/EGFRvIII analysis tested showed 100% sensitivity and specificity. We conclude that MLPA is a robust assay for detection of EGFR/EGFRvIII aberrations. While the exact diagnostic, prognostic and predictive value of such EGFR testing remains to be seen, MLPA has great potential as it can reliably and relatively easily be performed on routinely processed (formalin-fixed, paraffin-embedded) tumor tissue in combination with testing for other relevant glioma markers.
  Brain Pathology 11/2009; 19(4):661-71. · 3.99 Impact Factor
• Article: Phenotypic and genotypic characterization of orthotopic human glioma models and its relevance for the study of anti-glioma therapy.

  An Claes, Janneke Schuuring, Sandra Boots-Sprenger, Sandra Hendriks-Cornelissen, Marieke Dekkers, Albert J van der Kogel, William P Leenders, Pieter Wesseling, Judith W Jeuken
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  ABSTRACT: Most human gliomas are characterized by diffuse infiltrative growth in the brain parenchyma. Partly because of this characteristic growth pattern, gliomas are notorious for their poor response to current therapies. Many animal models for human gliomas, however, do not display this diffuse infiltrative growth pattern. Furthermore, there is a need for glioma models that represent adequate genocopies of different subsets of human gliomas (e.g., oligodendrogliomas). Here, we assessed the intracerebral growth patterns and copy number changes [using multiplex ligation-dependent probe amplification (MLPA)/comparative genomic hybridization (CGH)] of 15 human glioma lines in nude mice. Most xenografts present with compact growing lesions intracerebrally. Only the E98 and, to a lesser degree, E106 xenograft lines (propagated through subcutaneous growth) consistently produced intracerebral tumors, displaying diffuse infiltrative growth in the brain parenchyma. In contrast, four xenograft lines (E434, E468, E473 and E478), established by direct intracerebral inoculation of human glioma cells and serially propagated intracerebrally, consistently showed extensive diffuse infiltration throughout the brain. After several passages, the neoplastic cells still carry typical chromosomal aberrations [(-1p/-19q in oligodendroglioma, +7/-10 in glioblastoma multiforme (GBM)]. Especially these latter four models and the E98 line thus represent adequate geno- and phenocopies of human gliomas and form an attractive platform to investigate different therapeutic approaches in a preclinical setting.
  Brain Pathology 08/2008; 18(3):423-33. · 3.99 Impact Factor
• Article: RAS/RAF pathway activation in gliomas: the result of copy number gains rather than activating mutations.

  Judith Jeuken, Caroline van den Broecke, Sabine Gijsen, Sandra Boots-Sprenger, Pieter Wesseling
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  ABSTRACT: Aberrant RAS/RAF signaling has been reported to be important for many tumor types including gliomas. Activation of the RAS/RAF pathway can result from oncogenic mutations of RAS/RAF itself. However, such mutations have only occasionally been reported in gliomas. In order to further elucidate the role of RAS/RAF pathway activation in a histopathological and genetic spectrum of glioma subtypes (n = 93), we evaluated different types of aberrations in this pathway. Hotspot mutation analysis of BRAF, NRAS, KRAS, and HRAS revealed only two mutations, V600M in BRAF and G10E in NRAS, both occurring in pure oligodendroglial tumors. However, CGH analysis of 87 tumors revealed copy number gains including the above mentioned oncogenes in 38 of the neoplasms (44%) and including the upstream growth factors EGF, PDGF, IGF, FGF, TGF and/or their receptors in 46 tumors (53%). Phosphorylated MAPK (i.e. the activated compound downstream the RAS/RAF pathway) was detected by immunohistochemistry using tissue micro-arrays in the majority of gliomas. Interestingly, a significant correlation was found for nuclear MAPK-P staining and the number of these copy number gains (<or= 2 and >or= 3). These results indicate that RAS/RAF pathway activation in gliomas is achieved much more frequently by copy number gains including RAS/RAF and/or upstream growth factor (receptor) than by activating RAS/RAF mutations.
  Acta Neuropathologica 09/2007; 114(2):121-33. · 9.32 Impact Factor
• Article: Multiplex ligation-dependent probe amplification: a diagnostic tool for simultaneous identification of different genetic markers in glial tumors.

  Judith Jeuken, Sandra Cornelissen, Sandra Boots-Sprenger, Sabine Gijsen, Pieter Wesseling
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  ABSTRACT: Genetic aberrations in tumors are predictive for chemosensitivity and survival. A test is needed that allows simultaneous detection of multiple changes and that is widely applicable in a routine diagnostic setting. Multiplex ligation-dependent probe amplification (MLPA) allows detection of DNA copy number changes of up to 45 loci in one relatively simple, semiquantitative polymerase chain reaction-based assay. To assess the applicability of MLPA, we performed MLPA analysis to detect relevant genetic markers in a spectrum of 88 gliomas. The vast majority of these tumors (n = 79) were previously characterized by comparative genomic hybridization. With MLPA kit P088 (78 cases), complete and partial loss of 1p and 19q were reliably identified, even in samples containing only 50% tumor DNA. Distinct 1p deletions exist with different clinically prognostic consequences, and in contrast to the commonly used diagnostic strategies (loss of heterozygosity or fluorescent in situ hybridization 1p36), P088 allows detection of such distinct 1p losses. Combining P088 with P105 will further increase the accurate prediction of clinical behavior because this kit identified markers (EGFR, PTEN, and CDKN2A) of high-grade malignancy in 41 cases analyzed. We conclude that MLPA is a reliable diagnostic tool for simultaneous identification of different region-specific genetic aberrations of tumors.
  Journal of Molecular Diagnostics 10/2006; 8(4):433-43. · 3.58 Impact Factor
• Article: Molecular analysis as a tool in the differential diagnosis of VHL disease-related tumors.

  Johanna Gijtenbeek, Bram Jacobs, Sandra Boots-Sprenger, Anita Bonne, Jacques Lenders, Benno Küsters, Pieter Wesseling, Judith Jeuken
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  ABSTRACT: Von Hippel-Lindau (VHL) disease is an autosomal dominant tumor syndrome, in which hemangioblastomas (HBs), clear cell renal cell carcinomas (RCCs), and pheochromocytomas are the most frequently encountered tumors. The differential diagnosis of dedifferentiated tumors in general can be difficult, as standard histologic and immunohistochemical investigations do not always allow a definitive diagnosis. We used molecular genetic analysis to resolve the differential diagnosis of sarcomatoid RCC versus pheochromocytoma of a (peri)renal tumor in a VHL patient. Germline mutation analysis identified the C407T mutation, which has been related to a VHL phenotype in which pheochromocytomas are rare. Chromosomal imbalances detected in the tumor by CGH showed a pattern typical for RCCs and not for pheochromocytomas. CGH analysis of the multiple tumors of this VHL patient revealed a comparable karyotype in the metastatic tumors and the (peri)renal tumor. Concordantly, although the germline mutation was detected in all analyzed tumors, LOH 3p was only detected in the (peri)renal mass and most metastases. Overall, based on all genetic data, this tumor corroborated a diagnosis of metastatic sarcomatoid RCC. In line with these observations is the immunopositivity for the RCC-specific RC38 detected in the (peri)renal mass and the metastases that was not detected in pheochromocytomas. The RCC specific marker G250 was uninformative as it stains positive in all types of VHL tumors. This case report illustrates the promising role of genetic analysis in the differential diagnosis of histologically dedifferentiated tumors.
  Diagnostic Molecular Pathology 07/2005; 14(2):115-20. · 2.26 Impact Factor