26 results on '"Looijenga, Leendert H.J."'
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2. Heterogeneous distribution of ITGCNU in an adult testis: consequences for biopsy-based diagnosis
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Van Casteren, Niels J., Boellaard, Willem P.A., Dohle, Gert R., Weber, Robertus F.A., Kuizinga, Marti C., Stoop, Hans, Oosterhuis, Wolter J., and Looijenga, Leendert H.J.
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Carcinoma in situ -- Diagnosis ,Testicular cancer -- Diagnosis ,Germ cell tumors -- Diagnosis ,Germ cell tumors -- Case studies ,Health - Published
- 2008
3. The pluripotency homeobox gene NANOG is expressed in human germ cell tumors
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Hart, Adam H., Hartley, Lynne, Parker, Karen, Ibrahim, Marilyn, Looijenga, Leendert H.J., Pauchnik, Marija, Chow, Chung Wo, and Robb, Lorraine
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Germ cell tumors -- Genetic aspects ,Germ cell tumors -- Identification and classification ,Gene expression -- Analysis ,Tumors, Embryonal -- Genetic aspects ,Tumors, Embryonal -- Development and progression ,Health - Published
- 2005
4. Chromosomal anomalies in oligodendroglial tumors are correlated with clinical features
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Bent, Martin J. van den, Looijenga, Leendert H.J., Langenberg, K., Dinjens, Winand, Graveland, Wilfried, Uytdewilligen, Ludo, Smitt, Peter A. Sillevis, Jenkins, Robert B., and Kros, Johan M.
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Oligodendroglia -- Physiological aspects ,Oligodendroglia -- Genetic aspects ,Oligodendroglia -- Prognosis ,Human chromosome abnormalities -- Physiological aspects ,Health - Published
- 2003
5. Biallelic expression of the H19 and IGF2 genes in human testicular germ cell tumors
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Gurp, Ruud J.H.L.M. van, Oosterhuis, J. Wolter, Kalscheuer, Vera, Mariman, Edwin C.M., and Looijenga, Leendert H.J.
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Testicular cancer -- Genetic aspects ,Germ cell tumors -- Genetic aspects ,Disease susceptibility -- Genetic aspects ,Health - Published
- 1994
6. Utility of Serum miR-371a-3p in Predicting Relapse on Surveillance in Patients with Clinical Stage I Testicular Germ Cell Cancer
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Lobo, João, Leão, Ricardo, Gillis, Ad J.M., van den Berg, Annette, Anson-Cartwright, Lynn, Atenafu, Eshetu G., Kuhathaas, Kopika, Chung, Peter, Hansen, Aaron, Bedard, Philippe L., Jewett, Michael A.S., Warde, Padraig, O’Malley, Martin, Sweet, Joan, Looijenga, Leendert H.J., and Hamilton, Robert J.
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Optimal management of clinical stage I (CSI) testicular cancer is controversial due to lack of robust prognostic factors; miRNA-371a-3p holds promise as a biomarker, although its clinical utility for identifying patients at risk of relapse is unknown.
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- 2021
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7. Report From the International Society of Urological Pathology (ISUP) Consultation Conference on Molecular Pathology of Urogenital Cancers
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Looijenga, Leendert H.J., Van der Kwast, Theodorus H., Grignon, David, Egevad, Lars, Kristiansen, Glen, Kao, Chia-Sui, and Idrees, Muhammad T.
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Supplemental Digital Content is available in the text.The International Society of Urological Pathology (ISUP) organized a Consultation Conference in March 2019 dealing with applications of molecular pathology in Urogenital Pathology, including testicular tumors (with a focus on germ cell tumors [GCTs]), preceded by a survey among its members to get insight into current practices in testicular germ cell tumor (TGCT) diagnostics and adoption of the ISUP immunohistochemical guidelines published in 2014. On the basis of the premeeting survey, the most commonly used immunomarker panel includes OCT3/4, placental alkaline phosphate, D2-40, SALL4, CD117, and CD30 for GCTs and the documentation of germ cell neoplasia in situ (GCNIS). Molecular testing, specifically 12p copy gain, is informative to distinguish non-GCNIS versus GCNIS related GCTs, and establishing germ cell origin of tumors both in the context of primary and metastatic lesions. Other molecular methodologies currently available but not widely utilized for TGCTs include genome-wide and targeted approaches for specific genetic anomalies, P53 mutations, genomic MDM2 amplification, and detection of the p53 inactivating miR-371a-3p. The latter also holds promise as a serum marker for malignant TGCTs. This manuscript provides an update on the classification of TGCTs, and describes the current and future role of molecular-genetic testing. The following recommendations are made: (1) Presence of GCNIS should be documented in all cases along with extent of spermatogenesis; (2) Immunohistochemical staining is optional in the following scenarios: identification of GCNIS, distinguishing embryonal carcinoma from seminoma, confirming presence of yolk sac tumor and/or choriocarcinoma, and differentiating spermatocytic tumor from potential mimics; (3) Detection of gain of the short arm of chromosome 12 is diagnostic to differentiate between non-GCNIS versus GCNIS related GCTs and supportive to the germ cell origin of both primary and metastatic tumors.
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- 2020
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8. Interobserver Agreement in Vascular Invasion Scoring and the Added Value of Immunohistochemistry for Vascular Markers to Predict Disease Relapse in Stage I Testicular Nonseminomas
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Lobo, João, Stoop, Hans, Gillis, Ad J.M., Looijenga, Leendert H.J., and Oosterhuis, Wolter
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Supplemental Digital Content is available in the text.Vascular invasion has been identified as an informative risk factor for relapse in stage I testicular nonseminomas, used to tailor treatment. We investigated interobserver agreement in vascular invasion reporting and studied the potential additional value of immunohistochemistry for vascular markers for predicting relapse. Patients (n=52) with stage I testicular nonseminomas undergoing surveillance (1993-2006) were included (median follow-up of 66 mo). Two formalin-fixed paraffin-embedded blocks with >1 cm2tissue and tumor/normal parenchyma interface were stained with hematoxylin and eosin and CD31, FVIII, and D2-40. Slides were assessed by 3 independent testicular germ cell tumor-dedicated pathologists, and agreement was assessed using Cohen κ statistic. Sensitivity, specificity, and accuracy of vascular invasion scoring in predicting relapse were calculated. Agreement among testicular germ cell tumor-dedicated pathologists was moderate (κ=0.49 to 0.54), as was performance in predicting disease relapse (particularly, specificity of 86%). Immunohistochemistry increased overall sensitivity (71%), but decreased specificity (71%) in predicting relapse. All patients (n=8) with both blood and lymphatic vascular invasion developed a relapse. In multivariable analysis (including age, tumor size, rete testisinvasion, and serum tumor markers), only vascular invasion had an independent impact in predicting relapse. Assessment of vascular invasion by testicular germ cell tumor-dedicated pathologists is good and is clinically meaningful, predicting disease relapse. Immunohistochemistry for vascular markers improves sensitivity of detecting disease relapse and allows for the identification of high-risk patients with both blood and lymphatic vascular invasion simultaneously, potentially of interest for tailored chemotherapy.
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- 2019
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9. Cell-free MicroRNA miR-505-3p in Graft Preservation Fluid Is an Independent Predictor of Delayed Graft Function After Kidney Transplantation
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Roest, Henk P., Ooms, Liselotte S.S., Gillis, Ad J.M., IJzermans, Jan N.M., Looijenga, Leendert H.J., Dorssers, Lambert C.J., Dor, Frank J.M.F., and van der Laan, Luc J.W.
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Delayed graft function (DGF) is a complication affecting transplant outcome. In this paper the authors show that high levels of donor cell-free microRNA in the preservation fluid is associated with an increased risk of DGF after kidney transplantation.Supplemental digital content is available in the text.
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- 2019
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10. Improved Progression Prediction in Barrett’s Esophagus With Low-grade Dysplasia Using Specific Histologic Criteria
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ten Kate, Fiebo J.C., Nieboer, Daan, ten Kate, Fiebo J.W., Doukas, Michail, Bruno, Marco J., Spaander, Manon C.W., Looijenga, Leendert H.J., and Biermann, Katharina
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Supplemental Digital Content is available in the text.Risk stratification of patients with Barrett’s esophagus (BE) is based on diagnosis of low-grade dysplasia (LGD). LGD has a poor interobserver agreement and a limited value for prediction of progression to high-grade dysplasia or esophageal adenocarcinoma. Specific reproducible histologic criteria may improve the predictive value of LGD. Four gastrointestinal pathologists examined 12 histologic criteria associated with LGD in 84 BE patients with LGD (15 progressors and 69 nonprogressors). The criteria with at least a moderate (kappa, 0.4 to 0.6) interobserver agreement were validated in an independent cohort of 98 BE patients with LGD (30 progressors and 68 nonprogressors). Hazard ratios (HR) were calculated by Cox proportional hazard regression analysis using time-dependent covariates correcting for multiple endoscopies during follow-up. Agreement was moderate or good for 4 criteria, that is, loss of maturation, mucin depletion, nuclear enlargement, and increase of mitosis. Combination of the criteria differentiated high-risk and low-risk group amongst patients with LGD diagnosis (P<0.001). When ≥2 criteria were present, a significantly higher progression rate to high-grade dysplasia or esophageal adenocarcinoma was observed (discovery set: HR, 5.47; 95% confidence interval [CI], 1.81-17; P=0.002; validation set: HR, 3.52; 95% CI, 1.56-7.97; P=0.003). Implementation of p53 immunohistochemistry and histologic criteria optimized the prediction of progression (area under the curve, 0.768; 95% CI, 0.656-0.881). We identified and validated a clinically applicable panel of 4 histologic criteria, segregating BE patients with LGD diagnosis into defined prognostic groups. This histologic panel can be used to improve clinical decision making, although additional studies are warranted.
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- 2018
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11. DOC1-Dependent Recruitment of NURD Reveals Antagonism with SWI/SNF during Epithelial-Mesenchymal Transition in Oral Cancer Cells
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Mohd-Sarip, Adone, Teeuwssen, Miriam, Bot, Alice G., De Herdt, Maria J., Willems, Stefan M., Baatenburg de Jong, Robert J., Looijenga, Leendert H.J., Zatreanu, Diana, Bezstarosti, Karel, van Riet, Job, Oole, Edwin, van Ijcken, Wilfred F.J., van de Werken, Harmen J.G., Demmers, Jeroen A., Fodde, Riccardo, and Verrijzer, C. Peter
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The Nucleosome Remodeling and Deacetylase (NURD) complex is a key regulator of cell differentiation that has also been implicated in tumorigenesis. Loss of the NURD subunit Deleted in Oral Cancer 1 (DOC1) is associated with human oral squamous cell carcinomas (OSCCs). Here, we show that restoration of DOC1 expression in OSCC cells leads to a reversal of epithelial-mesenchymal transition (EMT). This is caused by the DOC1-dependent targeting of NURD to repress key transcriptional regulators of EMT. NURD recruitment drives extensive epigenetic reprogramming, including eviction of the SWI/SNF remodeler, formation of inaccessible chromatin, H3K27 deacetylation, and binding of PRC2 and KDM1A, followed by H3K27 methylation and H3K4 demethylation. Strikingly, depletion of SWI/SNF mimics the effects of DOC1 re-expression. Our results suggest that SWI/SNF and NURD function antagonistically to control chromatin state and transcription. We propose that disturbance of this dynamic equilibrium may lead to defects in gene expression that promote oncogenesis.
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- 2017
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12. NR5A1 is a novel disease gene for 46,XX testicular and ovotesticular disorders of sex development
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Baetens, Dorien, Stoop, Hans, Peelman, Frank, Todeschini, Anne-Laure, Rosseel, Toon, Coppieters, Frauke, Veitia, Reiner A., Looijenga, Leendert H.J., De Baere, Elfride, and Cools, Martine
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Purpose:We aimed to identify the genetic cause in a cohort of 11 unrelated cases and two sisters with 46,XX SRY-negative (ovo)testicular disorders of sex development (DSD).Methods:Whole-exome sequencing (n = 9), targeted resequencing (n = 4), and haplotyping were performed. Immunohistochemistry of sex-specific markers was performed on patients’ gonads. The consequences of mutation were investigated using luciferase assays, localization studies, and RNA-seq.Results:We identified a novel heterozygous NR5A1 mutation, c.274C>T p.(Arg92Trp), in three unrelated patients. The Arg92 residue is highly conserved and located in the Ftz-F1 region, probably involved in DNA-binding specificity and stability. There were no consistent changes in transcriptional activation or subcellular localization. Transcriptomics in patient-derived lymphocytes showed upregulation of MAMLD1, a direct NR5A1 target previously associated with 46,XY DSD. In gonads of affected individuals, ovarian FOXL2 and testicular SRY-independent SOX9 expression observed.Conclusions:We propose NR5A1, previously associated with 46,XY DSD and 46,XX primary ovarian insufficiency, as a novel gene for 46,XX (ovo)testicular DSD. We hypothesize that p.(Arg92Trp) results in decreased inhibition of the male developmental pathway through downregulation of female antitestis genes, thereby tipping the balance toward testicular differentiation in 46,XX individuals. In conclusion, our study supports a role for NR5A1 in testis differentiation in the XX gonad.Genet Med 19 4, 367–376.
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- 2017
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13. NR5A1is a novel disease gene for 46,XX testicular and ovotesticular disorders of sex development
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Baetens, Dorien, Stoop, Hans, Peelman, Frank, Todeschini, Anne-Laure, Rosseel, Toon, Coppieters, Frauke, Veitia, Reiner A., Looijenga, Leendert H.J., De Baere, Elfride, and Cools, Martine
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We aimed to identify the genetic cause in a cohort of 11 unrelated cases and two sisters with 46,XX SRY-negative (ovo)testicular disorders of sex development (DSD).
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- 2017
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14. Widespread somatic L1 retrotransposition occurs early during gastrointestinal cancer evolution
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Ewing, Adam D., Gacita, Anthony, Wood, Laura D., Ma, Florence, Xing, Dongmei, Kim, Min-Sik, Manda, Srikanth S., Abril, Gabriela, Pereira, Gavin, Makohon-Moore, Alvin, Looijenga, Leendert H.J., Gillis, Ad J.M., Hruban, Ralph H., Anders, Robert A., Romans, Katharine E., Pandey, Akhilesh, Iacobuzio-Donahue, Christine A., Vogelstein, Bert, Kinzler, Kenneth W., Kazazian, Haig H., and Solyom, Szilvia
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Somatic L1 retrotransposition events have been shown to occur in epithelial cancers. Here, we attempted to determine how early somatic L1 insertions occurred during the development of gastrointestinal (GI) cancers. Using L1-targeted resequencing (L1-seq), we studied different stages of four colorectal cancers arising from colonic polyps, seven pancreatic carcinomas, as well as seven gastric cancers. Surprisingly, we found somatic L1 insertions not only in all cancer types and metastases but also in colonic adenomas, well-known cancer precursors. Some insertions were also present in low quantities in normal GI tissues, occasionally caught in the act of being clonally fixed in the adjacent tumors. Insertions in adenomas and cancers numbered in the hundreds, and many were present in multiple tumor sections, implying clonal distribution. Our results demonstrate that extensive somatic insertional mutagenesis occurs very early during the development of GI tumors, probably before dysplastic growth.
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- 2015
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15. A genome-wide RNAi screen in mouse embryonic stem cells identifies Mp1 as a key mediator of differentiation
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Westerman, Bart A., Braat, A. Koen, Taub, Nicole, Potman, Marko, Vissers, Joseph H.A., Blom, Marleen, Verhoeven, Els, Stoop, Hans, Gillis, Ad, Velds, Arno, Nijkamp, Wouter, Beijersbergen, Roderick, Huber, Lukas A., Looijenga, Leendert H.J., and van Lohuizen, Maarten
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Despite intense investigation of intrinsic and extrinsic factors that regulate pluripotency, the process of initial fate commitment of embryonic stem (ES) cells is still poorly understood. We used a genome-wide short hairpin RNA screen in mouse ES cells to identify genes that are essential for initiation of differentiation. Knockdown of the scaffolding protein Mek binding protein 1 (Mp1, also known as Lamtor3 or Map2k1ip1) stimulated self-renewal of ES cells, blocked differentiation, and promoted proliferation. Fibroblast growth factor 4 (FGF4) signaling is required for initial fate commitment of ES cells. Knockdown of Mp1 inhibited FGF4-induced differentiation but did not alter FGF4-driven proliferation. This uncoupling of differentiation and proliferation was also observed when oncogenic Ras isoforms were overexpressed in ES cells. Knockdown of Mp1 redirected FGF4 signaling from differentiation toward pluripotency and up-regulated the pluripotency-related genes Esrrb, Rex1, Tcl1, and Sox2. We also found that human germ cell tumors (GCTs) express low amounts of Mp1 in the invasive embryonic carcinoma and seminoma histologies and higher amounts of Mp1 in the noninvasive carcinoma in situ precursor and differentiated components. Knockdown of Mp1 in invasive GCT cells resulted in resistance to differentiation, thereby showing a functional role for Mp1 both in normal differentiation of ES cells and in germ cell cancer.
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- 2011
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16. NANOG promoter methylation and expression correlation during normal and malignant human germ cell development
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Nettersheim, Daniel, Biermann, Katharina, Gillis, Ad J.M., Steger, Klaus, Looijenga, Leendert H.J., and Schorle, Hubert
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Testicular germ cell tumors are the most frequent malignant tumors in young Caucasian males, with increasing incidence. The actual model of tumorigenesis is based on the theory that a block in maturation of fetal germ cells lead to formation of the intratubular germ cell neoplasia unclassified. Early fetal germ cells and undifferentiated germ cell tumors express pluripotency markers such as the transcription factor NANOG. It has been demonstrated, that epigenetic modifications such as promoter DNA-methylation is able to silence gene expression in normal and cancer cells. Here we show, that OCT3/4-SOX2 mediated expression of NANOG can be silenced by methylation of promoter CpG-sites. We found that global methylation of DNA decreased from fetal spermatogonia to mature sperm. In contrast, CpGs in the NANOG promoter were found hypomethylated in spermatogonia and hypermethylated in sperm. This selective repression might reflect the cells need to suppress pluripotency in order to prevent malignant transformation. Finally, methylation of CpGs in the NANOG promoter in germ cell tumors and derived cell lines correlated to differentiation state.
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- 2011
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17. Critical Function of AP-2gamma/TCFAP2C in Mouse Embryonic Germ Cell Maintenance1
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Weber, Susanne, Eckert, Dawid, Nettersheim, Daniel, Gillis, Ad J.M., Schäfer, Sabine, Kuckenberg, Peter, Ehlermann, Julia, Werling, Uwe, Biermann, Katharina, Looijenga, Leendert H.J., and Schorle, Hubert
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Formation of the germ cell lineage involves multiple processes, including repression of somatic differentiation and reacquisition of pluripotency as well as a unique epigenetic constitution. The transcriptional regulator Prdm1has been identified as a main coordinator of this process, controlling epigenetic modification and gene expression. Here we report on the expression pattern of the transcription factor Tcfap2c, a putative downstream target of Prdm1, during normal mouse embryogenesis and the consequences of its specific loss in primordial germ cells (PGCs) and their derivatives. Tcfap2cis expressed in PGCs from Embryonic Day 7.25 (E 7.25) up to E 12.5, and targeted disruption resulted in sterile animals, both male and female. In the mutant animals, PGCs were specified but were lost around E 8.0. PGCs generated in vitro from embryonic stem cells lacking TCFAP2C displayed induction of Prdm1and Dppa3. Upregulation of Hoxa1, Hoxb1,and Ttogether with lack of expression of germ cell markers such Nanos3, Dazl,and Mutyhsuggested that the somatic gene program is induced in TCFAP2C-deficient PGCs. Repression of TCFAP2Cin TCam-2, a human PGC-resembling seminoma cell line, resulted in specific upregulation of HOXA1, HOXB1, MYOD1, and HAND1, indicative of mesodermal differentiation. Expression of genes indicative of ectodermal, endodermal, or extraembryonic differentiation, as well as the finding of no change to epigenetic modifications, suggested control by other factors. Our results implicate Tcfap2cas an important effector of Prdm1activity that is required for PGC maintenance, most likely mediating Prdm1-induced suppression of mesodermal differentiation.
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- 2010
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18. Genetic aspects of testicular germ cell tumors
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Krausz, Csilla and Looijenga, Leendert H.J.
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Testicular Germ Cell Tumor (TGCT) is the most common malignant tumor in young Caucasian men with an annual increase of 3-6% in the past 50 years. Data in the literature indicate that both environmental and genetic factors acting on the primordial gonocyte/gonocyte are implicated in the etiopathogenesis of this tumour. Genetic linkage and genome-wide analyses did not reveal a major gene effect so far, implying that multiple loci must contribute to the development of TGCTs. Only one significant genetic risk factor has been reported, the so called gr/gr deletion of the Y chromosome which still request further confirmation by independent studies. On the other side, the analysis of somatic genetic changes through mutation and genome imbalance analyses and expression profiling has just began to unravel the complex interaction of multiple pathways involved in TGCTs. This review focuses on genetic factors (both genomic and somatic) involved in the etiology, progression and treatment sensitivity of TGCTs.
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- 2008
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19. Extensive genetic alterations of the HLA region, including homozygous deletions of HLA class II genes in B-cell lymphomas arising in immune-privileged sites
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Riemersma, Sietske A., Jordanova, Ekaterina S., Schop, Roelandt F.J., Philippo, Katja, Looijenga, Leendert H.J., Schuuring, Ed, and Kluin, Philip M.
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In B-cell lymphomas, loss of human leukocyte antigen (HLA) class I and II molecules might contribute to immune escape from CD8+and CD4+cytotoxic T cells, especially because B cells can present their own idiotype. Loss of HLA expression and the possible underlying genomic alterations were studied in 28 testicular, 11 central nervous system, and 21 nodal diffuse large B-cell lymphomas (DLCLs), the first two sites are considered as immune-privileged sites. The analysis included immunohistochemistry, loss of heterozygosity analysis, and fluorescent in situ hybridization (FISH) on interphase cells and isolated DNA fibers. Total loss of HLA-A expression was found in 60% of the extranodal cases and in 10% of the nodal cases (P< .01), whereas loss of HLA-DR expression was found in 56% and 5%, respectively (P< .01). This was accompanied by extensive loss of heterozygosity within the HLA region in the extranodal DLCLs. In 3 cases, retention of heterozygosity for D6S1666 in the class II region suggested a homozygous deletion. This finding was confirmed by interphase FISH that showed homozygous deletions in the class II genes in 11 of the 18 extranodal lymphomas but in none of the 7 nodal DLCLs (P< .001). Mapping by fiber FISH showed variable deletions that always included HLA-DQ and HLA-DR genes. Hemizygous deletions and mitotic recombinations often involving all HLA genes were found in 13 of 18 extranodal and 2 of 7 nodal lymphomas. In conclusion, a structural loss of HLA class I and II expression might help the B-cell lymphoma cells to escape from immune attack.
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- 2000
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20. Restricted 12p Amplification and RAS Mutation in Human Germ Cell Tumors of the Adult Testis
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Roelofs, Helene, Mostert, Marijke C., Pompe, Kirsten, Zafarana, Gaetano, van Oorschot, Monique, van Gurp, Ruud J.H.L.M., Gillis, Ad J.M., Stoop, Hans, Beverloo, Berna, Oosterhuis, J. Wolter, Bokemeyer, Carsten, and Looijenga, Leendert H.J.
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Human testicular germ-cell tumors of young adults (TGCTs), both seminomas and nonseminomas, are characterized by 12p overrepresentation, mostly as isochromosomes, of which the biological and clinical significance is still unclear. A limited number of TGCTs has been identified with an additional high-level amplification of a restricted region of 12p including the K-RASproto-oncogene. Here we show that the incidence of these restricted 12p amplifications is ∼8% in primary TGCTs. Within a single cell formation of i(12p) and restricted 12p amplification is mutually exclusive. The borders of the amplicons cluster in short regions, and the amplicon was never found in the adjacent carcinoma in situcells. Seminomas with the restricted 12p amplification virtually lacked apoptosis and the tumor cells showed prolonged in vitrosurvival like seminoma cells with a mutated RASgene. However, no differences in proliferation index between these different groups of seminomas were found. Although patients with a seminoma containing a homogeneous restricted 12p amplification presented at a significantly younger age than those lacking it, the presence of a restricted 12p amplification/RASmutation did not predict the stage of the disease at clinical presentation and the treatment response of primary seminomas. In 55 primary and metastatic tumors from 44 different patients who failed cisplatinum-based chemotherapy, the restricted 12p amplification and RASmutations had the same incidence as in the consecutive series of responding patients. These data support the model that gain of 12p in TGCTs is related to invasive growth. It allows tumor cells, in particular those showing characteristics of early germ cells (ie, the seminoma cells), to survive outside their specific microenvironment. Overexpression of certain genes on 12p probably inhibits apoptosis in these tumor cells. However, the copy numbers of the restricted amplification of 12p and K-RASmutations do not predict response to therapy and survival of the patients.
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- 2000
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21. A molecular model for the development of germ cell cancer
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Looijenga, Leendert H.J., Munnik, Hannie de, and Oosterhuis, J.Wolter
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Human germ cell tumors comprise a heterogeneous group of neoplasms. Those of the adult testis, known as TGCTs, originate from carcinoma in situ (CIS), which are initiated during intra-uterine development. We present here a molecular model for the development of TGCTs, including various parameters, such as apoptosis, chromosomal constitution, as well as genomic imprinting. We assume that TGCTs originate from a pluripotent, erased embryonic germ cell, of which aneuploidization is one of the early events. Subsequently, net loss and gain of specific chromosomal regions result in the consistent pattern of chromosomal aberrations that are observed in these tumors, including gain of 12p-sequences. By means of analysis of a relatively small region of the short arm of chromosome 12, we are in the process of identifying the relevant genes. Possibly, this gene(s) suppresses apoptosis outside the specific micro-environment of the seminiferous tubule. Int. J. Cancer: 83:809814, 1999. © 1999 Wiley-Liss, Inc.
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- 1999
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22. Distinct p53-independent apoptotic cell death signalling pathways in testicular germ cell tumour cell lines
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Burger, Herman, Nooter, Kees, Boersma, Antonius W.M., Wingerden, Kyra E. van, Looijenga, Leendert H.J., Jochemsen, Aart G., and Stoter, Gerrit
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The induction of apoptosis by diverse apoptotic stimuli was studied in a panel of 6 testicular germ cell tumour(TGCT) cell lines with defined p53 status. Although the sensitivity to a particular stimulus varied considerably among the TGCT cell lines, the differences in response were not associated with the presence of functional p53. Mutant (mt) p53-expressing NCCIT and S2 (no p53 protein) were both readily triggered into apoptosis by cisplatin and doxorubicin, while wild-type(wt)-p53-transactivation-competent 2102 EP cells failed to undergo drug-induced apoptosis. Moreover, transactivation-deficient NCCIT cells and wtp53-expressing NT2 cells were equally sensitive to cisplatin, doxorubicin, gamma radiation, and cell-permeable C
2 -ceramide. Our p53 data suggest that, at least in this panel of non-isogeneic TGCT cell lines, hypersensitivity to therapeutic agents is not associated with p53 status. Next, we examined the impact of p53 inactivation on apoptosis induction in isogeneic NT2 sublines expressing human papillomavirus E6 protein. Evidently, abrogation of p53 function did not affect the hypersensitivity to apoptotic stimuli. We noted that drug-sensitive S2 cells were highly resistant to radiation-induced apoptosis, indicating distinct signalling pathways for chemotherapy and irradiation. The impaired radiation-induced apoptotic pathway in S2 and 2102 EP could not be restored by addition of cell-permeable C2 -ceramide, suggesting that the blockade is downstream of ceramide generation. Ligation of Fas/APO-1/CD95 by anti-Fas effectively induced apoptosis in Fas-antigen expressing S2, 2102 EP and 833 KE. The efficient Fas-mediated activation of apoptosis in drug-, radiation-, and ceramide-resistant 2102 EP cells further suggests that diverse apoptosis-inducing factors may use distinct signalling pathways. In summary, we demonstrated the presence of distinct p53-independent apoptotic pathways in TGCT cells. Int. J. Cancer 81:620628, 1999. © 1999 Wiley-Liss, Inc.- Published
- 1999
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23. Detection of Human Endogenous Retrovirus Type K-Specific Transcripts in Testicular Parenchyma and Testicular Germ Cell Tumors of Adolescents and Adults
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Roelofs, Helene, van Gurp, Ruud J.H.L.M., Oosterhuis, J. Wolter, and Looijenga, Leendert H.J.
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Testicular germ cell tumors (TGCTs) of adolescents and adults have been shown to contain proteins of the human endogenous retrovirus type K family. In a recent study, expression of these retroviral sequences was confirmed using in situhybridization, which also showed expression in carcinomain situ, the precursor of all TGCTs. Because of the clinical significance of a test for early diagnosis of TGCTs, we studied whether expression of human endogenous retrovirus type K genes could be an informative parameter. Therefore, we investigated TGCTs of various histologies and testicular parenchyma with and without carcinoma in situusing reverse transcription-polymerase chain reaction for expression of thegag, env, and prtgenes. The gagand prtgenes were expressed in all samples tested. The envtranscripts were not found in TGCTs showing somatic differentiation only but could be detected in most normal testicular parenchyma samples. Therefore, detection of human endogenous retrovirus type K transcripts cannot be used for early diagnosis of TGCTs. Simultaneous expression of multiplegagsequences was found both in normal parenchyma and TGCTs, and we demonstrated that expression of gagsequences with an extra G, necessary to generate a functional protein, was not limited to TGCTs.
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- 1998
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24. VASA mRNA (DDX4) detection is more specific than immunohistochemistry using poly- or monoclonal antibodies for germ cells in the male urogenital tract
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Boellaard, Willem P.A., Stoop, Hans, Gillis, Ad J.M., Oosterhuis, J. Wolter., Looijenga, Leendert H.J., and Alves., Marco G.
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Supplemental Digital Content is available in the text
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- 2017
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25. Value of cyclin A immunohistochemistry for cancer risk stratification in Barrett esophagus surveillance
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van Olphen, Sophie H., ten Kate, Fiebo J.C., Doukas, Michail, Kastelein, Florine, Steyerberg, Ewout W., Stoop, Hans A., Spaander, Manon C., Looijenga, Leendert H.J., Bruno, Marco J., Biermann, Katharina, and Žarko., Babić
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Supplemental Digital Content is available in the text
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- 2016
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26. Letter to the Editor
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Looijenga, Leendert H.J. and Oosterhuis, J. Wolter
- Published
- 2007
- Full Text
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