Search results for "Germ cell"
showing 10 items of 111 documents
Residential proximity to environmental pollution sources and risk of rare tumors in children.
2016
Background: Few epidemiologic studies have explored risk factors for rare tumors in children, and the role of environmental factors needs to be assessed. Objectives: To ascertain the effect of residential proximity to both industrial and urban areas on childhood cancer risk, taking industrial groups into account. Methods: We conducted a population-based case-control study of five childhood cancers in Spain (retinoblastoma, hepatic tumors, soft tissue sarcomas, germ cell tumors, and other epithelial neoplasms/melanomas), including 557 incident cases from the Spanish Registry of Childhood Tumors (period 1996-2011), and 3342 controls individually matched by year of birth, sex, and region of re…
Bax mutation and overexpression inversely correlate with immature phenotype and prognosis of childhood germ cell tumors
2007
Primary childhood germ cell tumors (GCTs) represent a rare and heterogeneous group of tumors that varies in histologic differentiation, age of presentation and clinical outcome. In malignant neoplasms, apoptosis is a prognostic marker and a predictive factor of response to therapy. Therefore, the study of the expression and mutation of molecules involved in the regulation of apoptosis could be useful in order to both predict the clinical outcome and design self-tailored therapeutic approaches. We retrospectively analysed tissue samples of 54 childhood GCTs. The expression of p53 and BAX protein was assessed by immunohistochemistry (IHC). Moreover, we investigated the presence of mutations i…
Intermediate filament protein profiles of human testicular non-seminomatous germ cell tumors: correlation of cytokeratin synthesis to cell differenti…
1991
Abstract The patterns of cytoskeletal differentiation were studied in 20 testicular non-seminomatous germ cell tumors by immunohistochemistry, using diverse monoclonal antibodies specific for different intermediate filament (IF) proteins and for desmoplakin. Immuno-fluorescence and immunoperoxidase methods on both formalin-fixed and frozen tissues were applied, in some cases together with a gel electrophoretic analysis of IF proteins. The tumors examined included embryonal carcinoma (EC), endodermal sinus tumor (EST), choriocar-cinoma and teratoma. Nine of the tumors were composed of only one histological type, the others showed mixed components. Cytokeratins 8 and 18 were identified in all…
Temporal trends in the incidence rate of childhood cancer in Germany 1987-2004.
2007
The German Childhood Cancer Registry regularly presents graphs of childhood cancer incidence rates by period, but no systematic analysis. The Automated Childhood Cancer Information System-project found an increasing trend in Europe. Against this background we present the first detailed trend analysis of childhood (aged under 15) malignancies in Germany. We examined incidence rates separately in western Germany 1987-2004 and eastern Germany 1991-2004. We analyzed all malignancies, all main diagnostic groups and relevant subsets using an age-period-cohort model. Additionally we fitted fractional polynomials to assess the linearity of the drift. All malignancies combined (excluding Central Ner…
Population-based epidemiologic data on brain tumors in German children.
2001
BACKGROUND Brain tumors are the most common disease group of solid tumors in childhood, and children with brain tumors have a relatively poor survival rate. Epidemiologic data from a population-based cancer registry provide the necessary information to obtain a full picture of the frequency of this disease, which is a great challenge in pediatric oncology. METHODS The German Childhood Cancer Registry (GCCR) is a population-based registry. The level of completeness of patient registration is 95%, but it is somewhat lower for patients with brain tumors. More than 300 children with newly diagnosed brain tumors are reported every year. Analyses of GCCR data are performed according to the Intern…
Human endogenous retrovirus rec interferes with germ cell development in mice and may cause carcinoma in situ, the predecessor lesion of germ cell tu…
2005
Germ cell tumors (GCTs) are among the most common malignancies in young men. We have previously documented that patients with GCT frequently produce serum antibodies directed against proteins encoded by human endogenous retrovirus (HERV) type K sequences. Transcripts originating from the env gene of HERV-K, including the rec-relative of human immunodeficiency virus rev, are highly expressed in GCTs. We report here that mice that inducibly express HERV-K rec show a disturbed germ cell development and may exhibit, by 19 months of age, changes reminiscent of carcinoma in situ, the predecessor lesion of classic seminoma in humans. This provides the first direct evidence that the expression of a…
Malignant germ cell tumors in childhood: results of the first Italian cooperative study "TCG 91".
2003
Background and Aims About 20% of patients with germ cell tumor (GCT) are still resistant to therapy. To investigate which features are present in resistant patients, a multicenter study on GCT in children was undertaken to correlate clinical and laboratory parameters with the outcome. Methods Patients aged less than 16 years, with histologically proven extracranial GCT were included. Results Ninety-five patients (median age 33 months, 45 males) were eligible. The site of the primary tumor was gonadal in 59, extragonadal in 36. The stage was I in 39; II in 5; IIIa (microscopic residue) in 7; IIIb (macroscopic residue) in 16; IIIc (unresectable) in 13; IV in 15. The treatment was surgery alon…
MicroRNA signature in various cell types of mouse spermatogenesis: Evidence for stage-specifically expressed miRNA-221, -203 and -34b-5p mediated spe…
2012
Background information Recently, it became apparent that microRNAs (miRNAs) can regulate gene expression post-transcriptionally. Despite the advances in identifying the testis-expressed miRNAs and their role in spermatogenesis, only few data are available showing the spatiotemporal expression of miRNAs during this process. Results To understand how different miRNAs can regulate germ cells differentiation, we generated a transgenic mouse model and purified pure populations of premeiotic (PrM) cells and primary spermatocytes (meiotic cells). We also established spermatogonial stem cell (SSC) culture using relatively simple and robust culture conditions. Comparison of global miRNA expression i…
Gene expression in mouse spermatogenesis during ontogenesis
2006
In this study, we evaluated the expression of genes probably involved in spermatogenesis in the mouse. We examined cytosolic chaperonin theta subunit (CCTtheta), Ngg1 interacting factor 3 like 1 binding protein 1 (NIF3L1 BP1) and apolipoprotein H (ApoH) expression during mouse onto-geny using RT-PCR. Testicular tissue was obtained from mice 3, 6, 8, 10, 12, 14, 18, 20 and 40 (adult) days after birth. For each mouse, one testis was used for histological examination, whereas RNA was extracted from the controlateral testis for expression analysis. RT-PCR analysis showed that CCTtheta gene expression was low until day 10, but increased drastically afterwards. At this age, spermatocytes started …
Dppa3 expression is critical for generation of fully reprogrammed iPS cells and maintenance of Dlk1-Dio3 imprinting.
2014
Reprogramming of mouse somatic cells into induced pluripotent stem cells (iPSCs) often generates partially reprogrammed iPSCs (pre-iPSCs), low-grade chimera forming iPSCs (lg-iPSCs) and fully reprogrammed, high-grade chimera production competent iPSCs (hg-iPSCs). Lg-iPSC transcriptome analysis revealed misregulated Dlk1-Dio3 cluster gene expression and subsequently the imprinting defect at the Dlk1-Dio3 locus. Here, we show that germ-cell marker Dppa3 is present only in lg-iPSCs and hg-iPSCs, and that induction with exogenous Dppa3 enhances reprogramming kinetics, generating all hg-iPSCs, similar to vitamin C (Vc). Conversely, Dppa3-null fibroblasts show reprogramming block at pre-iPSCs sta…