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Ed Schuuring

Publications and source records attributed to Ed Schuuring.

At least 19 recordsLinked to original sources
PubMed2025

Proposal of real-world solutions for the implementation of predictive biomarker testing in patients with operable non-small cell lung cancer.

The implementation of biomarker testing for targeted therapies and immune checkpoint inhibitors is a cornerstone in the management of metastatic and locally advanced non-small cell lung cancer (NSCLC), playing a pivotal role in guiding treatment decisions and patient care. The emergence of precision medicine in the realm of operable NSCLC has been marked by the recent approvals of osimertinib, atezolizumab, nivolumab, pembrolizumab and alectinib for early-stage disease, signifying a shift towards more tailored therapeutic strategies. Concurrently, the landscape of this disease is rapidly evolving, with several further pending approvals and numerous clinical trials in progress. To harness the benefits of these innovative neo-adjuvant and adjuvant therapies, the integration of predictive biomarker testing into standard clinical protocols is imperative for patients with operable NSCLC. A multidisciplinary international consortium has identified three primary obstacles impeding the effective testing of patients with operable NSCLC. These challenges encompass the limited number of test requests by physicians, the inadequacy of tissue samples for comprehensive testing, and the prevalence of cost-reduction measures leading to suboptimal testing practices. This review delineates the aforementioned challenges and proposed solutions, and strategic recommendations aimed at enhancing the testing process. By addressing these issues, we strive to optimize patient outcomes in operable NSCLC, ensuring that individuals receive the most appropriate and effective care based on their unique disease profile.

Humans↗
PubMed2006

High-resolution mapping identifies a commonly amplified 11q13.3 region containing multiple genes flanked by segmental duplications.

DNA amplification of the 11q13 region is observed frequently in many carcinomas. Within the amplified region several candidate oncogenes have been mapped, including cyclin D1, TAOS1 and cortactin. Yet, it is unknown which gene(s) is/are responsible for the selective pressure enabling amplicon formation. This is probably due to the use of low-resolution detection methods. Furthermore, the size and structure of the amplified 11q13 region is complex and consists of multiple amplicon cores that differ between different tumor types. We set out to test whether the borders of the 11q13 amplicon are restricted to regions that enable DNA breakage and subsequent amplification. A high-resolution array of the 11q13 region was generated to study the structure of the 11q13 amplicon and analyzed 29 laryngeal and pharyngeal carcinomas and nine cell lines with 11q13 amplification. We found that boundaries of the commonly amplified region were restricted to four segments. Three boundaries coincided with a syntenic breakpoint. Such regions have been suggested to be putatively fragile. Sequence comparisons revealed that the amplicon was flanked by two large low copy repeats known as segmental duplications. These segmental duplications might be responsible for the typical structure and size of the 11q13 amplicon. We hypothesize that the selection for genes through amplification of the 11q13.3 region is determined by the ability to form DNA breaks within specific regions and, consequently, results in large amplicons containing multiple genes.

Animals↗
PubMed2006

Assessment of gene promoter hypermethylation for detection of cervical neoplasia.

Current cervical cancer screening is based on morphological assessment of Pap smears and associated with significant false negative and false positive results. Previously, we have shown that detection of hypermethylated genes in cervical scrapings using quantitative methylation-specific PCR (QMSP) is a promising tool for identification of squamous cell cervical cancer. Aim of the present pilot-study was to evaluate presence of hypermethylated genes in cervical carcinogenesis, both in squamous cell as well as adenocarcinomas. Cervical scrapings were obtained from 30 patients diagnosed with cervical cancer (20 squamous cell carcinomas and 10 adenocarcinomas) and 19 women with histologically normal cervices. The scraped cells were used for determination of promoter hypermethylation by QMSP for 12 genes and for morphological assessment. Overall, CALCA, DAPK, ESR1, TIMP3, APC and RAR-beta2 promoters were significantly more often hypermethylated in cancers than in controls, while adenocarcinomas were more often hypermethylated above the highest control ratio for APC, TIMP3 and RASSF1A promoters. Combining 4 genes (CALCA, DAPK, ESR1 and APC) yielded a sensitivity of 89% (with all adenocarcinomas identified), equal to cytomorphology (89%) and high-risk human papilloma virus (Hr-HPV; 90%). The 4-gene QMSP proved theoretically superior to cytomorphology as well as Hr-HPV in specificity (100% vs. 83 and 68%, respectively), because cytology identified 3 controls as moderate or severe dyskaryosis and 6 controls were positive for Hr-HPV. In conclusions, QMSP of 4 gene promoters combined appears to have comparable sensitivity and potentially better specificity in comparison to "classic" cytomorphological assessment and Hr-HPV detection. QMSP holds promise as a new diagnostic tool for both squamous cell carcinoma and adenocarcinoma of the cervix.

DNA Methylation↗
PubMed2006

Prognostic impact of germinal center-associated proteins and chromosomal breakpoints in poor-risk diffuse large B-cell lymphoma.

PURPOSE: Outcome of diffuse large B-cell lymphoma (DLBCL) with a germinal center B-cell (GCB) expression profile is superior to that of non-GCB DLBCL. This conclusion is mainly derived from patients with mixed international prognostic index (IPI) risk profiles treated with CHOP-like therapy (cyclophosphamide, doxorubicin, vincristine, and prednisone). We wondered whether the prognostic impact of the expression profile would hold out in a homogeneous cohort of poor-risk DLBCL patients treated with high-dose sequential therapy (HDT) and autologous stem-cell transplantation (ASCT) as first-line therapy. PATIENTS AND METHODS: DLBCL from 66 newly diagnosed poor-risk patients, treated in two sequential prospective Dutch Hemato-Oncology Association (HOVON) trials, were studied retrospectively for expression of CD10, bcl6, MUM1/IRF4, bcl2, Ki67, and CD21+ follicular dendritic cells (FDC) by immunohistochemistry, and for the breakpoints of BCL2, BCL6, and MYC by fluorescent in situ hybridization (FISH). Lymphomas with any follicular component were excluded. RESULTS: A GCB immunophenotype profile was found in 58% and non-GCB immunophenotype profile in 42% of the tumors. Clinical characteristics of both groups were similar. Complete response (CR) rate was higher in patients with CD10+ tumors (58% v 30%; P = .03). A GCB immunophenotype profile, its constituting markers CD10 more than 30% and MUM1 less than 70%, and bcl2 less than 10% were each associated with a better overall survival (OS). FDC networks, equally present in GCB and non-GCB tumors, had superior CR (73% v 31%; P = .01), but disease-free survival rates were lower and there was no difference in OS rates. None of the breakpoints had a prognostic impact on outcome. CONCLUSION: Also in patients with poor-risk DLBCL treated with HDT and ASCT, the GCB immunophenotype and bcl2 expression retained a major impact on survival.

Adolescent↗
PubMed2006

Enhancement of human papilloma virus type 16 E7 specific T cell responses by local invasive procedures in patients with (pre)malignant cervical neoplasia.

It has been suggested that local invasive procedures may alter the natural course of (pre)malignant cervical disease. This could be due to partial excision of the lesions, or via induction of cellular immunity against human papillomavirus (HPV) by the local invasive procedures. We studied the influence of local invasive procedures on HPV-16 E7 specific immune responses in patients with different grades of cervical intra-epithelial neoplasia (CIN) and different stages of cervical cancer. Blood was obtained at intake and after invasive procedures from patients with CIN or cervical cancer. Antigen specific T-cell responses were measured by IFN-gamma ELISPOT analysis, after stimulation with recombinant HPV-16 E7 protein. As expected, HPV-16 E7 specific IFN-gamma T cell responses were more frequent in HPV-16 DNA positive patients compared with that in HPV-16 DNA negative patients (39/50 vs. 16/36, (p=0.006, chi2 test). After invasive procedures, a small number of HPV-16 DNA positive CIN patients, but a considerable proportion of HPV-16 DNA positive cervical cancer patients, showed an enhancement of T cell responses against HPV-16 E7. Induction of T cell reactivity was most pronounced in cervical cancer patients who had undergone previous invasive procedures. Both CD4+ and CD8+ T cells showed E7 specific IFN-gamma production upon in-vitro stimulation. Our study shows that invasive procedures may enhance HPV-specific cell-mediated immunity in a considerable number of patients with cervical cancer, but in only a minority of CIN patients. Our data indicate that invasive procedures should be considered as possible confounding factors when analyzing the effectiveness of therapeutic immunization studies, especially, when induction of HPV-specific immune responses is used as intermediate end-point.

Antigen Presentation↗
PubMed2006

Mechanisms and effects of loss of human leukocyte antigen class II expression in immune-privileged site-associated B-cell lymphoma.

PURPOSE AND EXPERIMENTAL DESIGN: Loss of human leukocyte antigen (HLA) expression on tumor cells is frequent in diffuse large B-cell lymphoma (DLBCL) arising in immune-privileged sites, such as the testis and central nervous system, and is associated with small homozygous deletions of HLA-DQ/HLA-DR and larger hemizygous deletions of the MHC region. To better understand the significance of down-regulation of HLA class II expression in relation to the homozygous and hemizygous deletions, we analyzed global gene expression patterns in a series of 26 testicular DLBCL after characterization of these deletions. RESULTS: Low levels of HLA-DR mRNA in whole testicular DLBCL samples were associated with a strong down-regulation of numerous immune-related genes specific for T cells, macrophages, antigen presentation and processing, lymphocyte activation, chemokines and chemokine receptors, and the complement system. The number of CD3+ tumor-infiltrating T cells was also significantly lower in low expressors of HLA-DR mRNA. Interestingly, hemizygous and homozygous deletions in the MHC region did not have any additional effect on global gene expression. CONCLUSION: In conclusion, we found that loss of HLA class II mRNA expression in testicular DLBCL is associated with a significant change in global gene expression patterns. This effect is independent of the mechanism causing the down-regulation of HLA class II genes in the lymphoma cells.

Centromere↗
PubMed2006

Transgenic mice with mammary gland targeted expression of human cortactin do not develop (pre-malignant) breast tumors: studies in MMTV-cortactin and MMTV-cortactin/-cyclin D1 bitransgenic mice.

BACKGROUND: In human breast cancers, amplification of chromosome 11q13 correlates with lymph node metastasis and increased mortality. To date, two genes located within this amplicon, CCND1 and EMS1, were considered to act as oncogenes, because overexpression of both proteins, respectively cyclin D1 and cortactin, correlated well with 11q13 amplification. Cyclin D1 is involved in cell cycle regulation and the F-actin-binding protein cortactin in cytoskeletal dynamics and cell migration. To study the role of cortactin in mammary gland tumorigenesis, we examined mouse mammary tumor virus (MMTV)-cortactin transgenic mice and MMTV-cortactin/-MMTV-cyclin D1 bitransgenic mice. METHODS: MMTV-cortactin transgenic mice were generated and intercrossed with previously described MMTV-cyclin D1 transgenic mice. Immunohistochemical, Northern and Western blot analyses were performed to study the expression of human transgene cortactin during mammary gland development and in mammary tumors. For tumor incidence studies, forced-bred, multiparous mice were used to enhance transgene expression in the mammary gland. Microscopical examination was performed using haematoxylin and eosin staining. RESULTS: Mammary gland tumors arose stochastically (incidence 21%) with a mean age of onset at 100 weeks. This incidence, however, did not exceed that of aged-matched control FVB/N mice (38%), which unexpectedly, also developed spontaneous mammary gland tumors. We mimicked 11q13 amplification by generating MMTV-cortactin/-MMTV-cyclin D1 bitransgenic mice but did not observe any synergistic effect of cortactin on cyclin D1-induced mammary hyperplasias or carcinomas, nor development of distant metastasis. CONCLUSION: From this study, we conclude that development of (pre-malignant) breast tumors in either wild type or MMTV-cyclin D1 mice was not augmented due to mammary gland targeted overexpression of human cortactin.

Animals↗
PubMed2006

Cortactin affects cell migration by regulating intercellular adhesion and cell spreading.

Cortactin is an F-actin binding protein that stabilizes F-actin networks and promotes actin polymerization by activating the Arp2/3 complex. Overexpression of cortactin, as observed in several human cancers, stimulates cell migration, invasion, and experimental metastasis; however, the underlying mechanism is not understood. To investigate the importance of cortactin in cell migration, we downregulated its expression using RNA interference (RNAi). Stable downregulation of cortactin in HBL100 breast epithelial cells resulted in (i) decreased cell migration and invasion, (ii) enhanced cell-cell adhesion, and (iii) accelerated cell spreading. These phenotypic changes were reversed by expression of RNAi-resistant mouse cortactin. Cortactin colocalized with cadherin and beta-catenin in adherens junctions, consistent with its role in intercellular adhesion. Remarkably, cortactin deficiency did not affect lamellipodia formation. Instead, downregulation of cortactin in human squamous carcinoma cells that overexpress cortactin changed the cytoskeletal organization. We conclude that increased levels of cortactin, as found in human carcinomas, promote cell migration and invasion by reducing cell spreading and intercellular adhesive strength.

Actin-Related Protein 2-3 Complex↗
PubMed2006

t(3;14)(p14;q32) results in aberrant expression of FOXP1 in a case of diffuse large B-cell lymphoma.

Strong expression of Forkhead box-P1 (FOXP1), a winged-helix transcription factor, has been identified as an independent prognostic factor in diffuse large B-cell lymphoma (DLBCL). However, possible mechanisms of deregulation of this gene, on 3p14.1, have yet to be elucidated. We have identified a breakpoint at the IGA1 gene in the immunoglobulin heavy chain (IGH) locus at 14q32 that was juxtaposed to the FOXP1 gene locus in a gastric DLBCL that showed strong expression of FOXP1. This may be one possible mechanism of deregulating FOXP1 expression by placing it under the control of IGH enhancers.

Base Sequence↗
PubMed2006

IGH switch breakpoints in Burkitt lymphoma: exclusive involvement of noncanonical class switch recombination.

Most chromosomal t(8;14) translocations in sporadic Burkitt lymphomas (BL) are mediated by immunoglobulin class switch recombination (CSR), yet all tumors express IgM, suggesting an incomplete or exclusively monoallelic CSR event. We studied the exact configuration of both the nontranslocated IGH allele and the MYC/IGH breakpoint by applying a combination of low- and high-resolution methods (interphase FISH, DNA fiber FISH, long-distance PCR, and Southern blotting) on 16 BL. IGH class switch events involving the nontranslocated IGH allele were not observed. Thirteen cases had MYC/IGH breakpoints in or nearby IGH switch (S) sites, including five at Smu, three at Sgamma and five at Salpha. All eight translocations with a breakpoint at Sgamma or Salpha were perfectly reciprocal, without deletion of Cmu-Cdelta or other CH elements. Internal Smu deletions claimed to be a marker for CSR activity and implicated in stabilization of IgM expression were found in BL but did not correlate with downstream translocation events. This study shows that switch breakpoints in sporadic BL are exclusively resolved by a noncanonical recombination mechanism involving only one switch region.

Adolescent↗
PubMed2006

An overview of innovative techniques to improve cervical cancer screening.

Although current cytomorphology-based cervical cancer screening has reduced the incidence of cervical cancer, Pap-smears are associated with high false positive and false negative rates. This has spurred the search for new technologies to improve current screening. New methodologies are automation of Pap-smear analysis, addition of new biological or molecular markers to traditional cytology or using these new markers to replace the current screening method. In this overview we will summarize data on cervical cancer epidemiology and etiology and the current cervical cancer screening approach. Available data on new screening approaches, such as quantitative cytochemistry, detection of loss of heterozygosity (LOH) and hypermethylation analysis will be reviewed. We discuss the potential of these approaches to replace or augment current screening. When available, data on cost-effectiveness of certain approaches will be provided. In short, Human Papillomavirus (HPV) DNA detection stands closest to implementation in nation-wide screening programs of all markers reviewed. However, specificity is low in women aged <35 years and the psychological effects of knowledge of HPV positivity in absence of cervical (pre) malignant disease are important drawbacks. In our opinion the results of large clinical trials should be awaited before proceeding to implement HPV DNA detection. New technologies based on molecular changes associated with cervical carcinogenesis might result in comparable sensitivity, but improved specificity. Hypermethylation analysis is likely to be more objective to identify patients with high grade squamous intra-epithelial lesions (HSIL) or invasive cancer with a higher specificity than current cytomorphology based screening.

Biomarkers, Tumor↗
PubMed2005

Cortactin overexpression results in sustained epidermal growth factor receptor signaling by preventing ligand-induced receptor degradation in human carcinoma cells.

The chromosome 11q13 region is frequently amplified in human carcinomas and results in an increased expression of various genes including cortactin, and is also associated with an increased invasive potential. Cortactin acts as an important regulator of the actin cytoskeleton. It is therefore very tempting to speculate that cortactin is the crucial gene within the 11q13 amplicon that mediates the invasive potential of these carcinomas. Cortactin also participates in receptor-mediated endocytosis, and recent findings have shown that, during receptor internalization, cortactin overexpression inhibits the ubiquitylation-mediated degradation of the epidermal growth factor receptor, resulting in a sustained ligand-induced epidermal growth factor receptor activity.

Carcinoma↗
PubMed2005

Comparative genome analysis of cortactin and HS1: the significance of the F-actin binding repeat domain.

BACKGROUND: In human carcinomas, overexpression of cortactin correlates with poor prognosis. Cortactin is an F-actin-binding protein involved in cytoskeletal rearrangements and cell migration by promoting actin-related protein (Arp)2/3 mediated actin polymerization. It shares a high amino acid sequence and structural similarity to hematopoietic lineage cell-specific protein 1 (HS1) although their functions differ considerable. In this manuscript we describe the genomic organization of these two genes in a variety of species by a combination of cloning and database searches. Based on our analysis, we predict the genesis of the actin-binding repeat domain during evolution. RESULTS: Cortactin homologues exist in sponges, worms, shrimps, insects, urochordates, fishes, amphibians, birds and mammalians, whereas HS1 exists in vertebrates only, suggesting that both genes have been derived from an ancestor cortactin gene by duplication. In agreement with this, comparative genome analysis revealed very similar exon-intron structures and sequence homologies, especially over the regions that encode the characteristic highly conserved F-actin-binding repeat domain. Cortactin splice variants affecting this F-actin-binding domain were identified not only in mammalians, but also in amphibians, fishes and birds. In mammalians, cortactin is ubiquitously expressed except in hematopoietic cells, whereas HS1 is mainly expressed in hematopoietic cells. In accordance with their distinct tissue specificity, the putative promoter region of cortactin is different from HS1. CONCLUSIONS: Comparative analysis of the genomic organization and amino acid sequences of cortactin and HS1 provides inside into their origin and evolution. Our analysis shows that both genes originated from a gene duplication event and subsequently HS1 lost two repeats, whereas cortactin gained one repeat. Our analysis genetically underscores the significance of the F-actin binding domain in cytoskeletal remodeling, which is of importance for the major role of HS1 in apoptosis and for cortactin in cell migration.

Actin-Related Protein 2↗
PubMed2005

Complex biallelic IGH rearrangements in IgM-expressing Z-138 cell line: Involvement of downstream immunoglobulin class switch recombination.

Chromosomal translocations involving the immunoglobulin (Ig) receptor loci usually disrupt and silence these loci. On the basis of observations in follicular lymphoma (FL) with downstream Ig heavy chain (IGH) class switch recombination (CSR), we hypothesized that downstream CSR-mediated chromosomal translocations would leave the V(D)J-Cmu transcription unit intact, thereby still allowing IgM expression from the IGH allele involved in the translocation. To test this hypothesis, we analyzed biallelic IGH translocations in the IgM-expressing cell line Z-138 by interphase FISH, DNA fiber-FISH, long-distance vectorette PCR, and DNA sequencing. One IGH allele was involved in a t(11;14), showing a break in the JH region that juxtaposed the Emu enhancer and the 3' Calpha enhancers to the cyclin D1 gene. The other IGH allele contained a t(8;14) breakpoint involving the 3' end of a Sgamma region, whereas the reciprocal breakpoint at 8q24 was approximately 40 kb centromeric of MYC. Molecular analysis showed that this IGH allele harbored a normal V(D)J-Cmu complex, which is responsible for IgM expression. These data show that chromosomal breakpoints such as the t(8;14) can occur in downstream IGH constant regions and do not necessarily interfere with Ig expression.

3' Flanking Region↗
PubMed2005

BCL6 alternative translocation breakpoint cluster region associated with follicular lymphoma grade 3B.

Translocations involving band 3q27, affecting the major breakpoint region (MBR) of BCL6, are common in diffuse large B-cell lymphomas (DLBCLs). Recent data suggest an alternative breakpoint cluster region (ABR) located between 245 and 285 kb 5' of BCL6, which might be associated with Follicular Lymphoma (FL). Ten DLBCLs and 9 FLs grade 3B with cytogenetic rearrangements at 3q27 were studied by fluorescence in situ hybridization (FISH) to discriminate between breakpoints at the ABR and MBR. Eight DLBCLs contained a breakpoint in the MBR, and 6 FL grade 3B (FL3B) cases contained a breakpoint in the ABR. No specific chromosomal partners could be identified in both groups. Previously published data have suggested that FL3B cases with 3q27 aberrations are closely related to the majority of DLBCLs of germinal center cell origin. However, our findings suggest that the mechanism of 3q27 rearrangement in FL3B cases is similar to the mechanism in follicular lymphomas grade 1,2, and 3A cases.

Chromosomes, Human, Pair 14↗
PubMed2005

Clinical, immunophenotypic, and genetic analysis of adult lymphomas with morphologic features of Burkitt lymphoma.

A prompt distinction of Burkitt lymphoma (BL) versus diffuse large B cell lymphomas (DLBCL) has important clinical implications; however, this distinction can be difficult. We analyzed 74 adult gray zone and 10 reference pediatric BL using immunohistochemistry (Ki-67, CD10, bcl2, bcl6) and fluorescence in situ hybridization (FISH) for MYC, BCL2, and BCL6 breakpoints. Two algorithms for classification were followed: algorithm A used a two-step review by four hemato-pathologists and algorithm B a set of only biologic markers (Ki-67 > or = 90%, CD10+, bcl6+, bcl2-, MYC breakpoint+, BCL2 and BCL6 breakpoint-). Both algorithms categorized all reference cases as BL. In the adult group, algorithm A resulted in 21 adult BL and 52 DLBCL and algorithm B in 23 BL and 51 "non-Burkitt" lymphomas (nBL); 9 cases (12%) contained two different translocations and were categorized as nBL in algorithm B. Fifteen cases (20%) fulfilled the BL criteria of both algorithms. Although not considered as BL according to both algorithms, many other lymphomas showed nonetheless a phenotypic and/or genetic shift to BL. BL according to algorithm B was more homogeneous with respect to clinical presentation (gender and localization) than BL defined by algorithm A. Our data suggest that only a few cases of these gray zone lymphomas represent true de novo BL. Immunohistochemistry for Ki-67, CD10, and bcl2 with analysis of MYC and preferably also BCL2 and BCL6 may be advised as a marker panel for this diagnostic dilemma.

Adolescent↗