Pathogenesis Of Testicular Germ Cell Tumors Research Articles

Occupational exposure to organic solvents and the risk of developing testicular germ cell tumors (TESTIS study): Effect of combined exposure assessment on risk estimation.

Etiological factors of testicular germ cell tumors (TGCT) remain largely unknown, but a causal role of occupational exposures to solvents has been suggested. Previous studies analyzing these exposures reported discordant results, potentially related to exposure assessment methods. The aim of this study was to investigate the role of occupational exposure to solvents on the risk of developing TGCT among young men. This study examined occupational exposures to solvents and TGCT risk based on the lifetime work histories of 454 cases and 670 controls, aged 18-45 years, of the French national TESTIS case-control study. Solvent exposure was estimated using: (i) exposure assignment by job-exposure matrix (JEM) and (ii) JEM combined with self-reported exposure data from specific questionnaires (SQ) and expert assessment (EA). Odds ratios (OR) and 95% confidence intervals (CI) were estimated using conditional logistic regression models. Both approaches (JEM and JEM+SQ+EA) showed a consistent association between TGCT and trichloroethylene exposure (exposed versus not exposed; JEM=OR 1.80 [95% confidence interval (CI) 1.12-2.90] and JEM+SQ+EA= OR 2.59 (95% CI 1.42-4.72). Both approaches also observed positive associations with ketone esters and fuels & petroleum-based solvents. The results suggest that some organic solvents might be involved in the pathogenesis of TGCT among occupationally exposed men. The combined use of JEM+SQ+EA seemed to limit misclassification by considering individual exposure variability and is, therefore, an appealing approach to assess occupational exposures in epidemiological studies.

The seminal plasma microbiome of men with testicular germ cell tumours described by small RNA sequencing.

It has been estimated that microorganisms are involved in the pathogenesis of approximately 20% of all cancers. Testicular germ cell tumours (TGCTs) are the most common type of malignancy in young men and arise from the precursor cell, germ cell neoplasia in situ (GCNIS). The microbiome of seminal plasma and testicular tissue has not been thoroughly investigated in regard to TGCTs. To investigate the differences in the seminal plasma microbiome between men with TGCT or GCNIS-only compared with controls. The study population consisted of patients with GCNIS-only (n=5), TGCT (n=18), and controls (n=25) with different levels of sperm counts in the ejaculate. RNA was isolated from the seminal plasma and sequenced. Reads not mapping to the human genome were aligned against a set of 2784 bacterial/archaeal and 4336 viral genomes using the Kraken pipeline. We identified reads from 2172 species and most counts were from Alteromonas mediterranea, Falconid herpesvirus 1, and Stigmatella aurantiaca. Six species (Acaryochloris marina, Halovirus HGTV-1, Thermaerobacter marianensis, Thioalkalivibrio sp. K90mix, Burkholderia sp. YI23, and Desulfurivibrio alkaliphilus) were found in significantly (q-value<0.05) higher levels in the seminal plasma of TGCT and GCNIS-only patients compared with controls. In contrast, Streptomyces phage VWB was found at significantly higher levels among controls compared with TGCT and GCNIS-only patients combined. Often the microbiome is analysed by shotgun or 16S ribosomal sequencing whereas our present data build on small RNA sequencing. This allowed us to identify more viruses and phages compared with previous studies but also makes the results difficult to directly compare. Our study is the first to report identification of the microbiome species in seminal plasma of men with TGCT and GCNIS-only, which potentially could be involved in the pathogenesis of TGCTs. Further studies are, however, needed to confirm our findings.

Association Study between Polymorphisms in DNA Methylation-Related Genes and Testicular Germ Cell Tumor Risk.

Testicular germ cell tumors (TGCT), histologically classified as seminomas and nonseminomas, are believed to arise from primordial gonocytes, with the maturation process blocked when they are subjected to DNA methylation reprogramming. SNPs in DNA methylation machinery and folate-dependent one-carbon metabolism genes have been postulated to influence the proper establishment of DNA methylation. In this pathway-focused investigation, we evaluated the association between 273 selected tag SNPs from 28 DNA methylation-related genes and TGCT risk. We carried out association analysis at individual SNP and gene-based level using summary statistics from the Genome Wide Association Study meta-analysis recently conducted by the international Testicular Cancer Consortium on 10,156 TGCT cases and 179,683 controls. In individual SNP analyses, seven SNPs, four mapping within MTHFR, were associated with TGCT risk after correction for multiple testing (q ≤ 0.05). Queries of public databases showed that three of these SNPs were associated with MTHFR changes in enzymatic activity (rs1801133) or expression level in testis tissue (rs12121543, rs1476413). Gene-based analyses revealed MTHFR (q = 8.4 × 10-4), methyl-CpG-binding protein 2 (MECP2; q = 2 × 10-3), and ZBTB4 (q = 0.03) as the top TGCT-associated genes. Stratifying by tumor histology, four MTHFR SNPs were associated with seminoma. In gene-based analysis MTHFR was associated with risk of seminoma (q = 2.8 × 10-4), but not with nonseminomatous tumors (q = 0.22). Genetic variants within MTHFR, potentially having an impact on the DNA methylation pattern, are associated with TGCT risk. This finding suggests that TGCT pathogenesis could be associated with the folate cycle status, and this relation could be partly due to hereditary factors.

LINC00313 regulates the metastasis of testicular germ cell tumors through epithelial-mesenchyme transition and immune pathways

ABSTRACT Testicular germ cell tumor (TGCT) is a relatively rare entity tumor, accounting for only 1% of all male cancers. However, it is the most common solid tumor in young men between 15 and 34 years old. Long noncoding RNAs (lncRNAs) are involved in various physiological and pathological processes. However, the functions of lncRNAs in TGCT have only rarely been investigated. LncRNAs associated with TGCT were identified using Gene Expression Omnibus (GEO) database and UCSC XENA database data mining. The effects of LINC00313 on NCCIT cell migration and invasion were evaluated in transwell assays. The expression levels of epithelial-mesenchyme transition (EMT)-related proteins in cells knockdown of LINC00313 were analyzed by Western blot. Correlation analyses between lncRNA LINC00313 expression and copy number variation (CNV) and immune cell infiltration were carried out using The Cancer Genome Atl as (TCGA) data. The effect of Panobinostatin targeting LINC00313 in TGCT cells was investigated. We observed higher LINC00313 expression in TGCT. The migratory and invasive properties of TGCT cells were augmented by LINC00313, likely via its effects on modulating the expression of epithelial-mesenchyme transition (EMT) related proteins: CTNNB1, ZEB1, CDH2, Snail and VIM. Moreover, LINC00313 expression and CNV correlated negatively with the infiltration of immune cells. In addition, Panobinostat might be a possible candidate drug to target LINC00313 in TGCT. LINC00313 performs important pro-migration and invasion functions in the pathogenesis of TGCT. LINC00313 could be used as diagnostic, prognostic, immune marker and therapeutic target to develop effective treatment of TGCT.

MP46-13 TEX11 SUPPRESS THE MIGRATION AND INVASION IN TESTICULAR GERM CELL TUMOR BY DOWN-REGULATED ITGB2

You have accessJournal of UrologyCME1 May 2022MP46-13 TEX11 SUPPRESS THE MIGRATION AND INVASION IN TESTICULAR GERM CELL TUMOR BY DOWN-REGULATED ITGB2 Wenjun Zhou Wenjun ZhouWenjun Zhou More articles by this author View All Author Informationhttps://doi.org/10.1097/JU.0000000000002612.13AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: Testis expressed gene 11 (TEX11) is a X-linked gene and mainly involved in meiotic arrest and male infertility, its role in the testicular germ cell tumor (TGCT) remains unknown. Thus, we aim to investigate the role of TEX11 in the pathogenesis of TGCT. METHODS: In this study, the overexpression plasmid of TEX11 (pcDNA-3.1+/TEX11) was constructed and transfected into NCCIT cell and Tcam-2 cell respectively. After transfection, the change of cell function was detected, including cell cycle, proliferation and apoptosis, migration and invasion. Furthermore, RNA sequence was used to investigated the gene expression profile alternation after TEX11 over-expression in Tcam-2 cell, genes with P value ≤ 0.05 and |log2FC| ≥ 1 were considered as differentially expressed genes (DEGs). GO and KEGG enrichment analyses were used to revealed the function of TEX11. RESULTS: The results showed that after overexpressed TEX11 in NCCIT and Tcam-2, its mRNA expression level was significantly increased. The Transwell indicated that TEX11 inhibited the migration and invasion ability of both NCCIT and Tcam-2 cells. Furthermore, the bioinformatics analysis showed that a total of 131 DEGs were detected in the sequence data, including 75 up-regulated DEGs and 56 down-regulated DEGs. The GO analysis showed that the down-regulated DEGs were significantly enriched in cellular process, biological regulation, protein binding, cell and cell part. KEGG pathway analysis revealed that these genes were mainly enriched in cell adhesion molecules (CAMs), ovarian steroidogenesis, NF-kappa B pathway and leukocyte transendothelial migration. Based on the phenotype change of migration and invasion ability, we chosen the differentially expressed gene ITGB2 from CAMs pathway, as a target gene. Using GEPIA database, we found that ITGB2 was significantly up-regulated in the TGCT tissue, and negatively related with the expression level of TEX11. CONCLUSIONS: In conclusion, we believed that TEX11 is a novel gene in the pathogenesis of TGCT. TEX11 may down-regulate ITGB2 gene through cell adhesion molecules pathway, thereby inhibit the invasion and migration ability of testicular germ cell tumor. Source of Funding: The work was supported by Graduate Independent Innovation Project Fund of Central South University (2020zzts229) © 2022 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 207Issue Supplement 5May 2022Page: e778 Advertisement Copyright & Permissions© 2022 by American Urological Association Education and Research, Inc.MetricsAuthor Information Wenjun Zhou More articles by this author Expand All Advertisement PDF DownloadLoading ...

Proximity to endocrine-disrupting pesticides and risk of testicular germ cell tumors (TGCT) among adolescents: A population-based case-control study in California.

The incidence of testicular germ cell tumors (TGCT) is increasing steadily in the United States, particularly among Latinos. TGCT is thought to be initiated in utero and exposure to endocrine-disrupting chemicals, suspected contributors to TGCT pathogenesis, during this critical developmental period may contribute to the rise. To assess the relationship between fetal exposure to agricultural endocrine-disrupting pesticides (EDPs) and TGCT risk among adolescents in a diverse population in California. We conducted a registry-based case-control study of TGCT. Cases, diagnosed between 1997 and 2011, were 15-19 years of age (n=381). Controls were matched on birth year and race/ethnicity (n=762). Quantities (kilograms) of 33 pesticides applied within 3 km and 1 km radii of each individual's address before birth were estimated using the Pesticide Use Reporting database. Odds ratios (OR), 95% confidence intervals (CI), and population attributable risk (PAR) were calculated for each EDP (using log-2 transformed values). Risk models considered race/ethnicity, birth year, and neighborhood socioeconomic status. A doubling of nearby acephate applications (3km and 1km radii) and malathion applications (1km radius) was associated with increased risks of TGCT among Latinos only (OR=1.09; 95% CI:1.01-1.17; 1.30; 95% CI:1.08-1.57, and 1.19; 95% CI:1.01-1.39, respectively), whereas application of carbaryl within a 3km radius increased TGCT risk in non-Latinos only (OR=1.14, 95% CI:1.01-1.28). We estimate that acephate was associated with approximately 10% of the TGCT PAR, malathion with 3% and carbaryl with 1%. TGCT among adolescents in California was associated with prenatal residential proximity to acephate and malathion among Latinos, and with carbaryl among non-Latinos. These results suggest that the rise in TGCT risk among Latinos may be associated with exposure to these pesticides.

A network-based approach to identify DNA methylation and its involved molecular pathways in testicular germ cell tumors.

Background: Testicular germ cell tumors (TGCT) is the most common testicular malignancy threaten young male reproductive health. This study aimed to identify aberrantly methylated-differentially expressed genes and pathways in TGCT by comprehensive bioinformatics analysis.Methods: Data of gene expression microarrays (GSE3218, GSE18155) and gene methylation microarrays (GSE72444) were collected from GEO database. Integrated analysis acquired aberrantly methylated-genes. Functional and pathway enrichment analysis were performed using DAVID database. Protein-protein interaction (PPI) network was constructed by STRING and App Mcode was used for module analysis. GEPIA platform and DiseaseMeth database were used for confirming the expression and methylation levels of hub genes. Finally, Human Protein Atlas database was performed to evaluate the prognostic significance.Results: Totally 604 hypomethylation-high expression and 147 hypermethylation-low genes were identified. The high expressed genes were enriched in biological processes of cell proliferation and migration. The top 8 hub genes of PPI network were GAPDH, VEGFA, PTPRC, RIPK4, MMP9, CSF1R, KRAS and FN1. After validation in GEPIA platform, all hub genes were elevated in TGCT tissues. Only MMP9, CSF1R and PTPRC showed hypomethylation-high expression status, which predicted the poor outcome of TGCT patients.Conclusion: Our study indicated possible aberrantly methylated-differentially expressed genes and pathways in TGCT by bioinformatics analysis, which may provide novel insights for unraveling pathogenesis of TGCT.

Recent Advances in New Discovered Molecular Targets in Testicular Germ Cell Tumors.

Testicular germ cell tumor (TGCT) is the most common solid malignancy occurring in young men between 20 and 34 years of age, and its incidence has increased significantly over the last decades. TGCTs can be subdivided into seminoma and nonseminoma germ cell tumors (NSGCTs), which includes yolk sac tumor, choriocarcinoma, embryonal cell carcinoma, and teratoma. Seminomas and NSGCTs present significant differences in therapy, prognosis, and both show characteristics of the Primordial Germ Cells (PGCs). I undertook a search of bibliographic data from peer-reviewed research literature. Seventy papers were included in the mini-review showing that a large number of new biomarkers have given further advantages to discriminate the different histotypes and could represent useful novel molecular targets for anticancer strategies. A deeper understanding of the pathogenesis of TGCTs is likely to significantly improve not only our knowledge on stem cells and oncogenesis but also the disease management with more selective tumor treatment.

Molecular Pathogenesis of Testicular Germ Cell Tumors

Testicular germ cell tumors (TGCT) are the most frequently diagnosed solid tumors in young men and their incidence has been increasing over the past decades. Several factors may combine and play a role in the TGCT etiology, including environmental factors and genetic predispositions at multiple genomic loci that affect both testicular germ cells and stromal cells, and their interactions within the testicular microenvironment. The pathogenesis of TGCT starts prenatally with primordial germ cell arrest, and further proceeds postnatally, giving rise to in situ germ cell neoplasia and, finally, to invasive TGCT with the characteristic 12p chromosome amplification. Apart from the genes localized here, further molecular mechanisms have been linked to TGCT pathogenesis, such as the activation of the KIT/KITL signaling pathway, and aberrations in genes involved in DNA reparation, regulation of cellular differentiation, proliferation, and survival. Despite the relatively good prognosis and known etiopathogenesis of these tumors, neither targeted therapy nor molecular prognostic/predictive factors have yet been implemented in the management of TGCT, because there is not enough information about the molecular pathways or molecules involved in TGCT development that could be used for patient stratification and treatment. Current high-throughput technologies, such as next generation sequencing at the exome or transcriptome level could provide this missing information on genetic predispositions and other factors influencing the clinical course of the disease and treatment response in TGCT. In this review, we summarize the main molecular characteristics of TGCT and the probable mechanisms participating in tumor initiation and progression.Key words: testicular germ cell tumors - signaling pathways - molecular aberrations - predictive factors - prognostic factors The work was supported by the Czech Ministry of Education, Youth and Sports NPU I nr.LO 1604. The authors declare they have no potential conflicts of interest concerning drugs, products, or services used in the study. The Editorial Board declares that the manuscript met the ICMJE recommendation for biomedical papers.Submitted: 20. 3. 2017Accepted: 23. 7. 2017.

Involvement of the DNA mismatch repair system in cisplatin sensitivity of testicular germ cell tumours.

Testicular germ cell tumours (TGCT) are highly sensitive to cisplatin-based chemotherapy, but patients with tumours containing differentiated teratoma components are less responsive to this treatment. The cisplatin sensitivity in TGCT has previously been linked to the embryonic phenotype in the majority of tumours, although the underlying mechanism largely remains to be elucidated. The aim of this study was to investigate the role of the DNA mismatch repair (MMR) system in the cisplatin sensitivity of TGCT. The expression pattern of key MMR proteins, including MSH2, MSH6, MLH1 and PMS2, were investigated during testis development and in the pathogenesis of TGCT, including germ cell neoplasia in situ (GCNIS). The TGCT-derived cell line NTera2 was differentiated using retinoic acid (10 μM, 6 days) after which MMR protein expression and activity, as well as cisplatin sensitivity, were investigated in both undifferentiated and differentiated cells. Finally, the expression of MSH2 was knocked down by siRNA in NTera2 cells after which the effect on cisplatin sensitivity was examined. MMR proteins were expressed in proliferating cells in the testes, while in malignant germ cells MMRprotein expression was found to coincide with the expression of the pluripotency factor OCT4, with no or low expression in the more differentiated yolk sac tumours, choriocarcinomas and teratomas. In differentiated NTera2 cells we found a significantly (p < 0.05) lower expression ofthe MMR and pluripotency factors, as well asa reduced MMR activity and cisplatin sensitivity, compared to undifferentiated NTera2 cells. Also, we found that partial knockdown of MSH2 expression in undifferentiated NTera2 cells resulted in a significantly (p < 0.001) reduced cisplatin sensitivity. This study reports, for the first time, expression of the MMR system in fetal gonocytes, from which GCNIS cells are derived. Our findings in primary TGCT specimens and TGCT-derived cells suggest that a reduced sensitivity to cisplatin in differentiated TGCT components could result from a reduced expression of MMR proteins, in particular MSH2 and MLH1, which are involved in the recognition of cisplatin adducts and in activation of the DNA damage response pathway to initiate apoptosis.

Wilms tumor gene 1 (WT1), TP53, RAS/BRAF and KIT aberrations in testicular germ cell tumors

PurposeWilms tumor gene 1 (WT1), a zinc-finger transcription factor essential for testis development and function, along with other genes, was investigated for their role in the pathogenesis of testicular germ cell tumors (TGCT). MethodsIn total, 284 TGCT and 100 control samples were investigated, including qPCR for WT1 expression and BRAF mutation, p53 immunohistochemistry detection, and massively parallel amplicon sequencing. ResultsWT1 was significantly (p < 0.0001) under-expressed in TGCT, with an increased ratio of exon 5-lacking isoforms, reaching low levels in chemo-naïve relapsed TGCT patients vs. high levels in chemotherapy-pretreated relapsed patients. BRAF V600E mutation was identified in 1% of patients only. p53 protein was lowly expressed in TGCT metastases compared to the matched primary tumors. Of 9 selected TGCT-linked genes, RAS/BRAF and WT1 mutations were frequent while significant TP53 and KIT variants were not detected (p = 0.0003). ConclusionsWT1 has been identified as a novel factor involved in TGCT pathogenesis, with a potential prognostic impact. Distinct biologic nature of the two types of relapses occurring in TGCT has been demonstrated. Differential mutation rate of the key TGCT-related genes has been documented.

Exome Sequencing of Bilateral Testicular Germ Cell Tumors Suggests Independent Development Lineages

Intratubular germ cell neoplasia, the precursor of testicular germ cell tumors (TGCTs), is hypothesized to arise during embryogenesis from developmentally arrested primordial germ cells (PGCs) or gonocytes. In early embryonal life, the PGCs migrate from the yolk sac to the dorsal body wall where the cell population separates before colonizing the genital ridges. However, whether the malignant transformation takes place before or after this separation is controversial. We have explored the somatic exome-wide mutational spectra of bilateral TGCT to provide novel insight into the in utero critical time frame of malignant transformation and TGCT pathogenesis. Exome sequencing was performed in five patients with bilateral TGCT (eight tumors), of these three patients in whom both tumors were available (six tumors) and two patients each with only one available tumor (two tumors). Selected loci were explored by Sanger sequencing in 71 patients with bilateral TGCT. From the exome-wide mutational spectra, no identical mutations in any of the three bilateral tumor pairs were identified. Exome sequencing of all eight tumors revealed 87 somatic non-synonymous mutations (median 10 per tumor; range 5-21), some in already known cancer genes such as CIITA, NEB, platelet-derived growth factor receptor α (PDGFRA), and WHSC1. SUPT6H was found recurrently mutated in two tumors. We suggest independent development lineages of bilateral TGCT. Thus, malignant transformation into intratubular germ cell neoplasia is likely to occur after the migration of PGCs. We reveal possible drivers of TGCT pathogenesis, such as mutated PDGFRA, potentially with therapeutic implications for TGCT patients.

Etiology and early pathogenesis of malignant testicular germ cell tumors: towards possibilities for preinvasive diagnosis.

Malignant testicular germ cell tumors (TGCT) are the most frequent cancers in Caucasian males (20–40 years) with an 70% increasing incidence the last 20 years, probably due to combined action of (epi)genetic and (micro)environmental factors. It is expected that TGCT have carcinoma in situ (CIS) as their common precursor, originating from an embryonic germ cell blocked in its maturation process. The overall cure rate of TGCT is more than 90%, however, men surviving TGCT can present long-term side effects of systemic cancer treatment. In contrast, men diagnosed and treated for CIS only continue to live without these long-term side effects. Therefore, early detection of CIS has great health benefits, which will require an informative screening method. This review described the etiology and early pathogenesis of TGCT, as well as the possibilities of early detection and future potential of screening men at risk for TGCT. For screening, a well-defined risk profile based on both genetic and environmental risk factors is needed. Since 2009, several genome wide association studies (GWAS) have been published, reporting on single-nucleotide polymorphisms (SNPs) with significant associations in or near the genes KITLG, SPRY4, BAK1, DMRT1, TERT, ATF7IP, HPGDS, MAD1L1, RFWD3, TEX14, and PPM1E, likely to be related to TGCT development. Prenatal, perinatal, and postnatal environmental factors also influence the onset of CIS. A noninvasive early detection method for CIS would be highly beneficial in a clinical setting, for which specific miRNA detection in semen seems to be very promising. Further research is needed to develop a well-defined TGCT risk profile, based on gene-environment interactions, combined with noninvasive detection method for CIS.

An up-date on newly discovered immunohistochemical biomarkers for the diagnosis of human testicular germ cell tumors.

Although testicular germ cell tumors (TGCTs) are relatively uncommon, they are particularly important, as they tend to affect children and young men, the most common tumor being in males aged from 20 to 40 years, and the incidence has been increasing in the last years. TGCTs comprise two major histologic groups: seminomas and non-seminomas germ cell tumors (NSGCTs). NSGCTs can be further divided into embryonal, carcinoma, Teratoma, yolk sac tumor, and choriocarcinoma. Seminomas and NSGCTs present significant differences in clinical features, therapy, and prognosis, and both show characteristics of the Primordial Germ Cells (PGCs). For proper diagnosis of the different histological subgroups, immunohistochemistry is required using different molecular markers, such as Aurora B, GPR30, Nek2, HMGA1, HMGA2, and others, and they could represent useful novel molecular targets for antineoplastic strategies. More insight into the pathogenesis of TGCTs is likely to contribute not only to better treatment of these tumors but also to a better understanding of stem cells and oncogenesis.

Recent advances in molecular and cell biology of testicular germ-cell tumors.

Testicular germ-cell tumors (TGCTs) are the most frequent solid malignant tumors in men 20-40 years of age and the most frequent cause of death from solid tumors in this age group. TGCTs comprise two major histologic groups: seminomas and nonseminomas germ-cell tumors (NSGCTs). NSGCTs can be further divided into embryonal, carcinoma, Teratoma, yolk sac tumor, and choriocarcinoma. Seminomas and NSGCTs present significant differences in clinical features, therapy, and prognosis, and both show characteristics of the primordial germ cells. Many discovered biomarkers including OCT3/4, SOX2, SOX17, HMGA1, Nek2, GPR30, Aurora-B, estrogen receptor β, and others have given further advantages to discriminate between histological subgroups and could represent useful novel molecular targets for antineoplastic strategies. More insight into the pathogenesis of TGCTs is likely to improve disease management not only to better treatment of these tumors but also to a better understanding of stem cells and oncogenesis.

Tumor-suppressive Function of Protein-tyrosine Phosphatase Non-receptor Type 23 in Testicular Germ Cell Tumors Is Lost upon Overexpression of miR142–3p microRNA

Protein-tyrosine phosphatase non-receptor type 23 (PTPN23) is a candidate tumor suppressor involved in the tumorigenesis of various organs. However, its physiological role(s) and detailed expression profile(s) have not yet been elucidated. We investigated the function and regulation of PTPN23 in the formation of testicular germ cell tumors (TGCTs). Expression of PTPN23 in human TGCT cell lines was significantly lower than that in spermatogonial stem cells in mice. Overexpression of PTPN23 in NEC8, a human TGCT cell line, suppressed soft agar colony formation in vitro and tumor formation in nude mice in vivo. These data indicate that PTPN23 functions as a tumor suppressor in TGCTs. Multiple computational algorithms predicted that the 3' UTR of human PTPN23 is a target for miR-142-3p. A luciferase reporter assay confirmed that miR-142-3p bound directly to the 3' UTR of PTPN23. Introduction of pre-miR-142 in the PTPN23 transfectant of NEC8 led to suppressed expression of PTPN23 and increased soft agar colony formation. Quantitative RT-PCR data revealed a significantly higher expression of miR-142-3p in human seminomas compared with normal testes. No difference in mRNA expression between seminoma and non-seminoma samples was detected by in situ hybridization. Both quantitative RT-PCR and immunohistochemical analyses revealed that PTPN23 expression was significantly lower in TGCTs than in normal testicular tissues. Finally, a lack of PTPN23 protein expression in human TGCTs correlated with a relatively higher miR-142-3p expression. These data suggest that PTPN23 is a tumor suppressor and that repression of PTPN23 expression by miR-142-3p plays an important role in the pathogenesis of TGCTs.

An Up-Date on the Molecular Biomarkers as Potential Therapeutic Targets in Human Testicular Germ Cell Tumors

Although testicular germ cell tumors (TGCTs) are relatively uncommon, they are particularly important as they tend to affect children and young men, representing the most common tumor in male aged from 20 to 40 years, and the in- cidence has increased in the last years. TGCTs comprise two major histologic groups: seminomas and non-seminomas germ cell tumors (NSGCTs). NSGCTs can be further divided into embryonal, carcinoma, teratoma, yolk sac tumor, and choriocarcinoma. Seminomas and NSGCTs present significant differences in clinical features, therapy, and prognosis, and both show characteristics of the Primordial Germ Cells (PGCs). For proper diagnosis of the different histological sub- groups, immunohistochemistry is required using different molecular markers, such as HMGA1, HMGA2, Aurora B, Nek2, and others and they could represent useful novel molecular targets for antineoplastic strategies. Recent develop- ments such as the discovery or the role of miRNAs in oncogenesis also revealed highly interesting features of TGCTs. Specific miRNAs were shown to be involved in bypassing the WT p53 pathway, which is another characteristic of TGCTs. More insight into the pathogenesis of TGCTs is likely to contribute not only to better treatment of these tumors but also to a better understanding of stem cells and oncogenesis.

Vitamin D Metabolism and Effects on Pluripotency Genes and Cell Differentiation in Testicular Germ Cell Tumors In Vitro and In Vivo

Testicular germ cell tumors (TGCTs) are classified as either seminomas or nonseminomas. Both tumors originate from carcinoma in situ (CIS) cells, which are derived from transformed fetal gonocytes. CIS, seminoma, and the undifferentiated embryonal carcinoma (EC) retain an embryonic phenotype and express pluripotency factors (NANOG/OCT4). Vitamin D (VD) is metabolized in the testes, and here, we examined VD metabolism in TGCT differentiation and pluripotency regulation. We established that the VD receptor (VDR) and VD-metabolizing enzymes are expressed in human fetal germ cells, CIS, and invasive TGCTs. VD metabolism diminished markedly during the malignant transformation from CIS to EC but was reestablished in differentiated components of nonseminomas, distinguished by coexpression of mesodermal markers and loss of OCT4. Subsequent in vitro studies confirmed that 1,25(OH)2D3 (active VD) downregulated NANOG and OCT4 through genomic VDR activation in EC-derived NTera2 cells and, to a lesser extent, in seminoma-derived TCam-2 cells, and up-regulated brachyury, SNAI1, osteocalcin, osteopontin, and fibroblast growth factor 23. To test for a possible therapeutic effect in vivo, NTera2 cells were xenografted into nude mice and treated with 1,25(OH)2D3, which induced down-regulation of pluripotency factors but caused no significant reduction of tumor growth. During NTera2 tumor formation, down-regulation of VDR was observed, resulting in limited responsiveness to cholecalciferol and 1,25(OH)2D3 treatment in vivo. These novel findings show that VD metabolism is involved in the mesodermal transition during differentiation of cancer cells with embryonic stem cell characteristics, which points to a function for VD during early embryonic development and possibly in the pathogenesis of TGCTs.

Abstract 4470: Pre-diagnostic gonadotropin levels and development of testicular germ cell tumors

Abstract INTRODUCTION: Testicular germ cell tumors (TGCT) are the most common cancer among young men (20-45 years of age). The pathogenesis of TGCT remains largely unknown; however, there is evidence that TGCT is related to other male reproductive disorders namely infertility and genitourinary malformations (cryptorchidism and hypospadias). It is generally assumed that the development of TGCT is under endocrine control and it has been hypothesized that gonadotropin dysregulation may be one potential cause of TGCT, as the testes are primary target organs for the gonadotropins, follicle-stimulating hormone (FSH) and luteinzing hormone (LH). FSH stimulates spermatogenesis via binding to receptors in Sertoli cells, while LH stimulates the Leydig cells to produce testosterone. Data support the role of primary LH deficiency in cryptorchidism, and also support the role of gonadotropin deficiency in infertility. It is currently not known whether FSH and LH levels are associated with TGCT risk. Thus, we assessed associations of pre-diagnostic serum FSH and LH concentrations and risk of TGCT among participants in the U.S. Servicemen's Testicular Tumor Environmental and Endocrine Determinants (STEED) Study. METHODS: TGCT cases diagnosed between 2002 and 2005 (n=517) were matched on age, race and serum draw date to at least one control (n=790). Associations between pre-diagnostic serum FSH and LH levels and TGCT were estimated using conditional logistic regression with further adjustment for prior cryptorchidism, family history of testicular cancer, height, body mass index and serum testosterone. Associations stratified on histology (seminoma, nonseminoma) were also examined. RESULTS: Overall, TGCT was associated with increased levels of FSH and decreased levels of LH. Men had an increased risk of TGCT if they were in the highest quartile of FSH [Q4 vs. Q1: OR 2.17, 95% CI 1.35-3.48] and in the lowest quartile of LH [Q1 vs. Q4: OR 1.99, 95% CI 1.25-3.16]. These associations were independent of one another and independent of serum testosterone concentration. In analyses stratified by histologic subtype the increased risk of TGCT with high FSH [Q4 vs. Q1: OR 2.86, 95% CI 1.33-6.18] and low LH [Q1 vs. Q4: OR 2.55, 95% CI 1.18, 5.49] was consistent for seminomas. Among nonseminomas, the ORs were indicative of elevated TGCT risk with high FSH [Q4 vs. Q1: OR 1.81, 95% CI 0.96-3.43] and low LH [Q1 vs. Q4: OR 1.80, 95% CI 0.97-3.36], albeit the results did not attain statisitical significance. DISCUSSION: Our findings of associations of TGCT with FSH and LH suggest that gonadotropin disruption may be a critical event in development of TGCT. LH deficiency has previously been associated with risk factors for TGCT, cryptorchidism and infertility, while high levels of FSH may indicate a defect in Sertoli cell production of inhibin B, a negative feedback regulator of FSH. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 4470. doi:1538-7445.AM2012-4470

Pilot Study of the Association between the HLA Region and Testicular Carcinoma among Croatian Patients

Objectives: To analyze the distribution of HLA alleles and HLA microsatellite alleles in Croatian patients with testicular carcinoma, compare it with that of healthy controls and investigate whether the polymorphism within the HLA region could be associated with the development of testicular cancer. Methods: Genomic DNA was isolated from the peripheral blood of 24 patients with testicular germ cell tumors (TGCT). Patients and controls were typed for HLA class I and class II polymorphism by the PCR-SSO method. Nine HLA microsatellites were analyzed by PCR and electrophoresis in an automated sequencer. Results: No significant deviation in the distribution of frequencies at HLA class I alleles was observed between patients and controls. Among HLA class II alleles, a statistically significant increase in the frequency of the HLA-DPB1*1701 allele was found among patients. The frequency of the HLA-DRB1*07-DQA1*0201-DQB1*0202 haplotype was increased in patients in comparison to the controls. Analysis of HLA microsatellites showed an increased frequency of D6S291-3 allele (p_corr = 0.0455, OR = 3.05) among patients. Conclusions: The observed association of the disease and the DPB1*1701 allele as well as with the D6S291-3 allele suggests that this part of the HLA region might be involved in the pathogenesis of TGCT. Our data provide a basis for further studies about the correlation between the HLA region and testicular cancer.